US20010007391A1 - Air bag apparatus for passenger seat - Google Patents

Abstract

An air bag apparatus for a passenger seat has reduced deploying speed and reduces the impact of the air bag on an occupant moving forward at the time of a crash of a vehicle. A gas generator is disposed in a case of the air bag apparatus, extending in a fore-to-aft direction relative to the vehicle. The gas generator case contains a cylindrical inflator extending in the fore-to-aft direction. An air bag is disposed in the apparatus case, folded in a predetermined manner. An inner bag for controlling gas flow is disposed in the air bag, folded in a predetermined manner. An auxiliary inner bag is sewed to an outside surface of a bag of the inner bag. When the inner bag is inflated and deployed, the bag of the inner bag presses a portion of the air bag against the windshield, and the auxiliary inner bag presses another portion of the air bag against the instrument panel.

Description

INCORPORATION BY REFERENCE
• The disclosure of Japanese Patent Application No. HEI 9-338846 filed on Dec. 9, 1997 including the specification, drawings and abstract is incorporated herein by reference in its entirety.[0001]
BACKGROUND OF THE INVENTION
• 1. Field of the Invention[0002]
• The present invention relates to an air bag apparatus for a passenger seat for protecting an occupant in the passenger seat in a vehicle such as a motor vehicle and the like.[0003]
• 2. Description of the Related Art[0004]
• A known air bag apparatus for a passenger seat is described in, for example, Japanese Patent Application Laid-open No. Hei 7-215151.[0005]
• In conjunction with the air bag apparatus for a passenger seat, the laid-open patent application proposes an air bag folding manner such that the air bag will be deployed toward an occupant's torso during an early period of deployment. Furthermore, in this air bag apparatus for a passenger seat, the resistance or drag that occurs when the air bag is unfolded from the folded state is utilized to reduce the deploying speed of the air bag.[0006]
• However, in a typical air bag apparatus for a passenger seat, the air bag needs to be tightly folded in order to minimize the size of the entire apparatus. Therefore, there is a danger that at the time of an impact on the vehicle, the air bag may not completely unfold but may remain partially folded or packed when an occupant moves forward by inertia and contacts the air bag. Also, in a typical air bag arrangement, gas is directly jetted into the air bag from the inflator, so that it is difficult to control the direction of gas flow in the air bag. Therefore, it is difficult to control the direction of deployment of the air bag.[0007]
SUMMARY OF THE INVENTION
• Accordingly, it is an object of the present invention to provide a passenger seat air bag arrangement having a reduced deploying speed.[0008]
• According to a first aspect of the invention, there is provided an air bag apparatus for a passenger seat disposed in a passenger seat-side instrument panel. The air bag apparatus includes an air bag folded and disposed in a case having at one side thereof an opening, and an inner bag disposed in the air bag so that the inner bag is inflated prior to inflation of the air bag. The inner bag is designed to press a portion of the air bag against at least one of a front glass pane and an instrument panel when inflated.[0009]
• With this construction, the air bag is inflated and deployed, dragging between the inner bag and the front glass pane and/or between the inner bag and the instrument panel. Sliding friction that occurs at the dragging portions reduces the deploying speed of the air bag with respect to conventional air bag arrangements. Therefore, even if an occupant comes into contact with the air bag before the deployment is completed (during the deployment), the air bag will not strongly contact the occupant.[0010]
• One alternative construction features providing a supply hole in the inner bag for supplying gas to the air bag.[0011]
• This construction makes it possible to adjust the deploying speed of the air bag by suitably selecting the size and number of supplying holes formed in the inner bag.[0012]
• According to an alternative construction, the inner bag may be designed to press a portion of the air bag against each of the front glass pane and the instrument panel. The air bag is inflated and deployed, dragging between the inner bag and the front glass pane and between the inner bag and the instrument panel. Sliding friction that occurs on the dragging portions further reduces the deploying speed of the air bag. According to another alternative construction, the inner bag may have an upper inflating portion and a lower inflating portion. The upper inflating portion is formed so as to inflate to a greater size than the lower inflating portion.[0013]
• This optional construction ensures that a large area of the inner bag presses against the front glass pane even if the front glass pane is far apart from the instrument panel. Therefore, the deploying speed of the upper portion of the air bag can be effectively reduced.[0014]
• According to an alternative construction, a restriction member may be disposed in the inner bag. The restriction member restricts inflation of a central portion of the inner bag to a predetermined amount and defines, at least partially, two inflating portions in the inner bag.[0015]
• This construction enhances the pressing of the inner bag against the front glass pane and the instrument panel, thereby more reliably reducing the deploying speed of the air bag.[0016]
• The inner bag may be formed by sewing an upper face to a lower face cloth. The upper face cloth is inflated and deployed in an upward direction relative to the vehicle. The lower face cloth is inflated and deployed in a downward direction relative the vehicle.[0017]
• This construction ensures that the upper face cloth will press a portion of the air bag against the front glass pane and the lower face cloth will press another portion of the air bag against the instrument panel. Therefore, the deploying speed of the air bag can be reliably reduced.[0018]
• The restriction member may extend from an end of at least one of the upper face cloth and the lower face cloth. This construction facilitates production of the inner bag.[0019]
• The restriction member may be disposed in the inner bag at a lower position therein so that an upward deploying portion of the inner bag is inflated and deployed to a greater size than a downward deploying portion of the inner bag.[0020]
• This construction ensures that the upper face cloth will press a portion of the air bag against the front glass pane, thereby reliably reducing the deploying speed of the air bag.[0021]
• The inner bag may be formed by two base cloths so that when the inner bag is inflated and deployed, the base cloths face each other in transverse directions relative to the vehicle and the inner bag is inflated and deployed in upward and downward directions relative to the vehicle.[0022]
• This construction makes it possible to sufficiently inflate and deploy the inner bag in the upward and downward directions relative to the vehicle and therefore reduce the deploying speed of the air bag, without requiring a restriction member or the like that is disposed in the inner bag for restricting the amount of inflation of a central portion of the inner bag. Therefore, the structure of the inner bag can be simplified.[0023]
• The inner bag may assume a generally gourd shape in a side view when it is inflated. With this construction, when the inner bag is inflated and deployed, the tensions on the bag portions of the inner bag repel each other at a constricted portion therebetween and therefore resist collapse in vertical directions. Therefore, the inner bag continues pressing portions of the air bag against the front glass pane and the instrument panel until the inflating deployment of the[0024]bag32 is completed. Consequently, the deploying speed of the air bag will be more effectively reduced.
• The inner bag may contact the front glass pane and the instrument panel so as to curve into a generally crescent shape in a side view when it is inflated. When the inner bag contacts the front glass pane and the instrument panel, gas pressure inside the inner bag urges the inner bag to inflate into a designed deployment shape, so that the force of the inner bag pressing against the front glass pane and the instrument panel is increased. Since the sliding friction caused on portions of the air bag that drag between the inner bag and the front glass pane and between the inner bag and the instrument panel is also increased, the deploying speed of the air bag will be more effectively reduced.[0025]
• The inner bag may have an extension portion that extends in a rearward direction relative to the vehicle. The extension portion presses a portion of the air bag against the instrument panel. The extension portion actively presses a portion of the air bag against the instrument panel, so that a portion of the air bag will be reliably sandwiched between the extension portion and the instrument panel. Therefore, the deploying speed of the air bag will be reliably reduced.[0026]
• The inner bag may have a forward ejection hole for ejecting gas in a forward direction relative to the vehicle.[0027]
• With this construction, when the inner bag is inflated, the air bag is deployed also in the forward direction by gas supplied through the forward ejection hole. Therefore, a forward portion of the air bag is additionally pressed against the front glass pane and the instrument panel by gas supplied thereinto. Consequently, the sliding resistance occurring when the air bag is deployed is further increased, thereby further reducing the deploying speed of the air bag.[0028]
• During assembly of the air bag apparatus, before it is put into its case, the air bag may be folded by folding portions of the air bag that face in forward and rearward directions relative to the vehicle and then folding portions of the air bag that face in transverse directions relative to the vehicle.[0029]
• This construction enables smooth inflation and deployment of the air bag in the transverse directions relative to the vehicle. Furthermore, since the portions of the air bag that face in forward and rearward directions relative to the vehicle are folded before the portions of the air bag that face in transverse directions relative to the vehicle are folded, the air bag is deployed in the transverse directions prior to the deployment in the fore-to-aft directions. Therefore, the deploying speed of the air bag toward the occupant side is further reduced.[0030]
• The inner bag may be folded by folding opposite end portions thereof that face in the transverse directions relative to the vehicle while avoiding folding a central portion of the air bag relative to the case, in the transverse directions.[0031]
• During an early period of deployment of the air bag, the entire folded portions facing in the fore-to-aft directions are quickly protruded from the upper surface of the instrument panel as the inner bag is inflated and deployed. Therefore, the air bag is inflated and deployed more smoothly in the transverse directions, so that the deploying speed of the air bag toward the occupant side will be reliably reduced.[0032]
• An inflator having a cylindrical shape may be disposed so that an axis thereof extends substantially in a fore-to-aft direction relative to the vehicle.[0033]
• During an early period of deployment of the air bag, the entire folded portions of the air bag facing in the fore-to-aft directions are reliably protruded from the upper surface of the instrument panel as the inner bag is inflated and deployed. Therefore, the deploying speed of the air bag toward the occupant side will be more reliably reduced.[0034]
• A portion of the air bag may be disposed between an inner wall face of the case and right and left sides of the inflator. This construction enables compact packaging of the air bag in the case.[0035]
• The air bag apparatus for a passenger seat may be constructed to include a fixing portion at which the air bag is fixed to the case and a mouth portion that guides gas into the air bag. The mouth portion is disposed in a central portion of the case. An upward deploying portion of the air bag and a downward deploying portion of the air bag are folded and disposed in a space between the mouth portion and one of opposite inner surfaces of the case that face the mouth portion and a space between the mouth portion and the other one of the opposite inner surfaces of the case, respectively.[0036]
• This construction enables compact packaging of the air bag in the case while improving the deploying performance of the air bag.[0037]
• An air bag cover may be disposed at the opening of the case. The air bag cover can be opened in transverse directions relative to the vehicle in a manner of a double-hinged door.[0038]
• With this construction, the air bag cover will not interfere with the inflating deployment of the inner bag and the air bag toward the occupant side. Furthermore, this construction reliably prevents the cover from contacting an occupant when the cover breaks open.[0039]
• The air bag apparatus can be constructed to include an outlet hole for exhausting gas, and the inner bag has a supply hole for supplying gas to the air bag. The air bag and the inner bag are disposed in the case in such a manner that the outlet hole of the air bag and the supply hole of the inner bag correspond to each other, and so that, during inflation of the inner bag and the air bag, the supply hole and the outlet hole become separate from each other.[0040]
• With this construction, during an early period of the deployment of the inner bag, gas introduced into the inner bag flows out through the supply hole of the inner bag and through the outlet hole of the air bag, so that the gas pressure inside the inner bag decreases and, therefore, the deploying speed of the inner bag also decreases. Therefore, if an occupant contacts the air bag and presses the inner bag during the deployment of the inner bag, the inflation of the air bag afterwards is weakened, thereby substantially preventing strong contact of the air bag with the occupant.[0041]
• According to the first aspect of the invention, the outlet hole of the air bag and the supply hole of the inner bag may be sewed together at peripheral portions thereof so as to correspond to each other, using a thread that breaks when the air bag and the inner bag are inflated.[0042]
• With this construction, during an early period of the deployment of the inner bag, gas flows out of the inner bag through the supply hole of the inner bag and through the outlet hole of the air bag without fail, so that the gas pressure inside the inner bag reliably decreases and, therefore, the deploying speed of the inner bag reliably decreases. Therefore, even if an occupant contacts the air bag and thus presses the inner bag during an early period of the deployment of the inner bag, strong contact of the inner bag with the occupant will be substantially prevented.[0043]
• A site in the inner bag and a site in the air bag that come closest to an occupant side at the time of completion of inflation and deployment of the inner bag and the air bag may be interconnected so that the sites remain interconnected during an early period of the inflation of the inner bag and the air bag, and so that the sites are disconnected from each other as the inner bag and the air bag are further inflated.[0044]
• The interconnection between the aforementioned sites reduces the deploying speed of the air bag toward the occupant side. Therefore, even if at the time of a vehicle crash, an occupant moves forward and comes into contact with the air bag before it is completely deployed, strong contact of the air bag with the occupant will be prevented.[0045]
• A second aspect of the invention provides an air bag apparatus for a passenger seat disposed in a passenger seat-side instrument panel. The air bag apparatus includes an air bag having an outlet hole for exhausting gas. The air bag is folded and disposed in a case having at one side thereof an opening. The inner bag has a supply hole for supplying gas to the air bag. The inner bag is disposed in the air bag so that the inner bag is inflated prior to inflation of the air bag. The air bag and the inner bag are disposed in the case in such a manner that the outlet hole of the air bag and the supply hole of the inner bag correspond to each other. During inflation of the inner bag and the air bag, the supply hole and the outlet hole become separate from each other.[0046]
• Early during deployment of the inner bag, gas introduced into the inner bag flows out through the supply hole of the inner bag and through the outlet hole of the air bag, so that the gas pressure inside the inner bag decreases and, therefore, the deploying speed of the inner bag also decreases. Therefore, if an occupant contacts the air bag and presses the inner bag during the deployment of the inner bag, the inflation of the air bag afterwards is weakened, thereby substantially preventing strong contact of the air bag with the occupant.[0047]
• In this second aspect of the invention, the outlet hole of the air bag and the supply hole of the inner bag may be sewed together at peripheral portions thereof so as to correspond to each other, using a thread that breaks when the air bag and the inner bag are inflated.[0048]
• With this construction, during an early period of deployment of the inner bag, gas flows out of the inner bag through the supply hole of the inner bag and through the outlet hole of the air bag without fail, so that the gas pressure inside the inner bag reliably decreases and, therefore, the deploying speed of the inner bag reliably decreases. Therefore, even if an occupant contacts the air bag and thus presses the inner bag during an early period of the deployment of the inner bag, strong contact of the inner bag with the occupant will be substantially prevented.[0049]
• The inner bag may be provided with a duct extending therefrom corresponding to the supply hole. In this case, the inner bag and the air bag are folded and disposed in the case in such a manner that the duct protrudes out from the outlet hole of the air bag.[0050]
• With this construction, there is no need to sew a peripheral portion of the supply hole of the inner bag to a peripheral portion of the outlet hole of the air bag. Therefore, the production efficiency of the air bag apparatus for a passenger seat can be improved.[0051]
• As a construction alternative, a site in the inner bag and a site in the air bag that come closest to an occupant side at the time of completion of inflation and deployment of the inner bag and the air bag may be interconnected so that the sites remain interconnected during an early period of the inflation of the inner bag and the air bag, and so that the sites are disconnected from each other as the inner bag and the air bag are further inflated.[0052]
• The interconnection between the aforementioned sites reduces the deploying speed of the air bag toward the occupant side. Therefore, even if at the time of a vehicle crash, an occupant moves forward and comes into contact with the air bag before it is completely deployed, strong contact of the air bag with the occupant will be prevented.[0053]
• According to a third aspect of the invention, there is provided an air bag apparatus for a passenger seat disposed in a passenger seat-side instrument panel. The air bag apparatus includes an air bag folded and disposed in a case having at one side thereof an opening, and an inner bag disposed in the air bag so that the inner bag is inflated prior to inflation of the air bag. A site in the inner bag and a site in the air bag that come closest to an occupant side at the time of completion of inflation and deployment of the inner bag and the air bag are interconnected so that the sites remain interconnected during an early period of the inflation of the inner bag and the air bag, and so that the sites are disconnected from each other as the inner bag and the air bag are further inflated.[0054]
• The interconnection between the aforementioned sites reduces the deploying speed of the air bag toward the occupant side. Therefore, even if at the time of a vehicle crash, an occupant moves forward and comes into contact with the air bag before it is completely deployed, strong contact of the air bag with the occupant will be prevented.[0055]
• The inner bag has a supply hole for supplying gas to the air bag. This construction makes it possible to adjust the deploying speed of the air bag by suitably selecting the size and number of supplying holes.[0056]
• A site in the inner bag and a site in the air bag that come closest to an occupant side at the time of completion of inflation and deployment of the inner bag and the air bag may be interconnected by a restriction member that is folded and sewed with a breakable thread so that the folded sections of the restriction member are joined together.[0057]
• With this construction, during an early period of the deployment of the air bag, the deploying direction of the air bag is restricted by the restriction member after the breakable thread joining the folded sections thereof breaks.[0058]
• The interconnected sites in the inner bag and the air bag may be directly sewed together using a thread that breaks when the inner bag and the air bag are inflated.[0059]
• This construction reduces the deploying speed of the air bag without requiring a complicated arrangement. Furthermore, during an early period of the deployment of the air bag, since the deploying direction of the air bag is restricted by the site connected to the inner bag, the air bag is stably inflated and deployed.[0060]
BRIEF DESCRIPTION OF THE DRAWINGS
• The foregoing and further objects, features and advantages of the present invention will become apparent from the following description of preferred embodiments with reference to the accompanying drawings, wherein like numerals are used to represent like elements and wherein:[0061]
• FIG. 1 is a perspective view of an air bag apparatus for a passenger seat according to a first embodiment of the invention;[0062]
• FIG. 2 is a schematic longitudinal sectional view of the apparatus illustrated in FIG. 1, taken along a plane extending in a fore-to-aft direction relative to the vehicle, wherein the air bag is deployed;[0063]
• FIG. 3 is an enlarged transverse sectional view of the apparatus illustrated in FIG. 1, taken along a right-to-left extending plane, wherein the air bag apparatus is installed;[0064]
• FIG. 4 is an enlarged sectional view taken along a fore-to-aft extending plane, that is, a plane perpendicular to the plane employed in FIG. 3;[0065]
• FIG. 5 is a perspective view of the air bag of the air bag apparatus for a passenger seat, illustrating the procedure of folding the air bag;[0066]
• FIG. 6 is a perspective view illustrating the procedure of folding the air bag that follows the procedure shown in FIG. 5;[0067]
• FIG. 7 is a perspective view illustrating the procedure of folding the air bag that follows the procedure shown in FIG. 6;[0068]
• FIG. 8 is a schematic perspective view of the air bag apparatus, illustrating an early state of deployment;[0069]
• FIG. 9 is a schematic perspective view illustrating a deploying state that follows the state shown in FIG. 8;[0070]
• FIG. 10 is a schematic perspective view illustrating a deploying state that follows the state shown in FIG. 9;[0071]
• FIG. 11 is a plan view of an air bag apparatus for a passenger seat according to a second embodiment of the invention;[0072]
• FIG. 12 is an exploded perspective view of the air bag apparatus for a passenger seat shown in FIG. 11;[0073]
• FIG. 13 is a plan view of an inner bag, illustrating a production process of the inner bag;[0074]
• FIG. 14 is a plan view illustrating a production process of the inner bag that follows the process in FIG. 13;[0075]
• FIG. 15 is a schematic sectional view taken on line XV-XV of FIG. 11;[0076]
• FIG. 16 is a rear view of the air bag, illustrating the procedure of folding the air bag;[0077]
• FIG. 17 is a side view of the air bag, illustrating the same folding step as in FIG. 16;[0078]
• FIG. 18 a rear view of the air bag, illustrating a folding step that follows the step shown in FIG. 16;[0079]
• FIG. 19 is a schematic sectional view taken on line XIX-XIX of FIG. 18;[0080]
• FIG. 20 is a schematic sectional view of the air bag apparatus for a passenger seat of the second embodiment taken in a fore-to-aft extending plane, wherein the apparatus is installed;[0081]
• FIG. 21 is a schematic sectional view of the apparatus, illustrating an early state of the deployment;[0082]
• FIG. 22 is a schematic sectional view illustrating a deploying state that follows the state shown in FIG. 21;[0083]
• FIG. 23 is a schematic sectional view illustrating a deploying state that follows the state shown in FIG. 22;[0084]
• FIG. 24 is a schematic sectional view illustrating a deploying state that follows the state shown in FIG. 23;[0085]
• FIG. 25 is a plan view illustrating a production process of an inner bag according to a third embodiment of the invention;[0086]
• FIG. 26 is a schematic sectional view of an air bag according to the third embodiment;[0087]
• FIG. 27 is a plan view illustrating a production process of an inner bag according to a fourth embodiment of the invention;[0088]
• FIG. 28 is a schematic sectional view of an air bag according to the fourth embodiment;[0089]
• FIG. 29 is a plan view of an inner bag according to a modification of the embodiment;[0090]
• FIG. 30 is a plan view of an air bag according to a fifth embodiment of the invention;[0091]
• FIG. 31 is a plan view illustrating a production process of the inner bag;[0092]
• FIG. 32 is a plan view illustrating a production process that follows the process shown in FIG. 31;[0093]
• FIG. 33 is a plan view illustrating a production process that follows the process shown in FIG. 32;[0094]
• FIG. 34 is a schematic sectional view taken along line XXXIV-XXXIV of FIG. 30;[0095]
• FIG. 35 is a schematic sectional view of an air bag apparatus of the fifth embodiment, taken on a fore-to-aft extending plane, wherein the apparatus is installed;[0096]
• FIG. 36 is a schematic sectional view of the air bag apparatus in an early state of the deployment;[0097]
• FIG. 37 is a schematic sectional view of the air bag apparatus in a deploying state that follows the state shown in FIG. 36;[0098]
• FIG. 38 is a schematic sectional view of the air bag apparatus in a deploying state that follows the state shown in FIG. 37;[0099]
• FIG. 39 is a schematic sectional view of the air bag apparatus in a deploying state that follows the state shown in FIG. 38;[0100]
• FIG. 40 is a plan view of an inner bag according to a sixth embodiment of the invention;[0101]
• FIG. 41 is a schematic sectional view of an air bag apparatus of the sixth embodiment, illustrating a deploying state thereof;[0102]
• FIG. 42 is a schematic sectional view of the air bag apparatus in a deploying state that follows the state shown in FIG. 41;[0103]
• FIG. 43 is a schematic sectional view of the air bag apparatus in a deploying state that follows the state shown in FIG. 42;[0104]
• FIG. 44 is a plan view of an air bag according to a seventh embodiment of the invention;[0105]
• FIG. 45 is a left-side plan view illustrating a step of folding an inner bag;[0106]
• FIG. 46 is a right-side plan view of the inner bag in the folding step illustrated in FIG. 45;[0107]
• FIG. 47 is a top plan view of the inner bag, illustrating a folding step that follows the step shown in FIG. 45;[0108]
• FIG. 48 is a top plan view of the inner bag, illustrating a folding step that follows the step shown in FIG. 47;[0109]
• FIG. 49 is a schematic sectional view of an air bag apparatus according to the seventh embodiment, taken along a fore-to-aft extending plane, wherein the apparatus is installed;[0110]
• FIG. 50 is a schematic sectional view of the air bag apparatus in an early state of the deployment;[0111]
• FIG. 51 is a schematic sectional view of the air bag apparatus in a deploying state that follows the state shown in FIG. 50;[0112]
• FIG. 52 is a schematic sectional view of the air bag apparatus in a deploying state that follows the state shown in FIG. 51;[0113]
• FIG. 53 is a schematic sectional view of the air bag apparatus in a deploying state that follows the state shown in FIG. 52;[0114]
• FIG. 54 is a perspective view of an air bag apparatus for a passenger seat according to an eighth embodiment of the invention;[0115]
• FIG. 55 is a schematic sectional view of the air bag apparatus in an early state of deployment;[0116]
• FIG. 56 is a schematic sectional view of the air bag apparatus that has been deployed to a state that follows the state shown in FIG. 55;[0117]
• FIG. 57 is a schematic sectional view of the air bag apparatus in a deploying state that follows the state shown in FIG. 56;[0118]
• FIG. 58 is a perspective view of an air bag apparatus for a passenger seat according to a ninth embodiment of the invention, wherein the air bag is being deployed;[0119]
• FIG. 59 is a schematic sectional view of the air bag apparatus in an early state of deployment;[0120]
• FIG. 60 is a schematic sectional view of the air bag apparatus in a deploying state that follows the state shown in FIG. 59;[0121]
• FIG. 61 is a schematic sectional view of the air bag apparatus in a deploying state that follows the state shown in FIG. 60;[0122]
• FIG. 62 is a horizontal sectional view of an air bag apparatus for a passenger seat according to a tenth embodiment of the invention;[0123]
• FIG. 63 is a horizontal sectional view of an air bag of the air bag apparatus, wherein the air bag is folded and housed in the case;[0124]
• FIG. 64 is a horizontal sectional view of the air bag apparatus in an early state of deployment;[0125]
• FIG. 65 is a horizontal sectional view of an air bag apparatus for a passenger seat according to an eleventh embodiment of the invention;[0126]
• FIG. 66 is a horizontal sectional view of an air bag of the air bag apparatus, wherein the air bag is folded and housed in the case;[0127]
• FIG. 67 is a horizontal sectional view of the air bag apparatus in an early state of deployment;[0128]
• FIG. 68 is a schematic sectional view of a air bag apparatus for a passenger seat according to a twelfth embodiment of the invention, taken along a plane extending in the fore-to-aft directions relative to the vehicle;[0129]
• FIG. 69 is a sectional view illustrating a deployment completed state of the apparatus;[0130]
• FIG. 70 is a schematic sectional view of an air bag apparatus according to a construction of the second through twelfth embodiments, taken along a fore-to-aft extending plane;[0131]
• FIG. 71 is a schematic sectional view of an air bag apparatus according to another construction of the second through twelfth embodiments, taken along a fore-to-aft extending plane;[0132]
• FIG. 72 is a schematic sectional view of an air bag apparatus according to still another construction of the second through twelfth embodiments, taken along a fore-to-aft extending plane;[0133]
• FIG. 73 is a schematic sectional view of an air bag apparatus according to a further construction of the second through twelfth embodiments, taken along a fore-to-aft extending plane; and[0134]
• FIG. 74 is a schematic sectional view of an air bag apparatus according to an alternative construction of the second through twelfth embodiments, taken along a fore-to-aft extending plane.[0135]
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
• Preferred embodiments of the present invention will be described in detail hereinafter with reference to the accompanying drawings.[0136]
• First Embodiment[0137]
• A first embodiment of the invention will be described with reference to FIGS. 1 through 10.[0138]
• Referring to FIGS. 1 and 2, an air bag apparatus for a passenger seat (hereinafter, referred to as “passenger seat-side air bag apparatus”)[0139]11 is disposed in an upper portion of a passenger seat-side portion of aninstrument panel13 that faces afront windshield12 of a vehicle such as a motor vehicle and the like. Theinstrument panel13 has anouter shell13aand anopening13b.
• The passenger seat-side[0140]air bag apparatus11 is fixed inside theinstrument panel13, at a position corresponding to theopening13bof theinstrument panel13. As shown in FIG. 3, acase16 of the passenger seat-sideair bag apparatus11 has the shape of a box without a lid, and an upper opening portion of thecase16 is provided with acover14 firmly attached thereto by aband15. Abreakable groove14aextends in the fore-to-aft direction relative the vehicle in a lower surface of a central portion of thecover14.
• A[0141]gas generator24 is disposed inside thecase16, extending in the fore-to-aft direction relative to the vehicle. Disposed inside acase19 of thegas generator24 is a cylindrical or tubular inflator18 (hereinafter inflator18) whose axis extends also in the fore-to-aft direction. The inflator18 generates gas by burning a gas generating agent or the like disposed therein. Thecase19 of thegas generator24 has a plurality ofgas ejecting openings20 for releasing gas while rectifying gas flow. Thus, thecase19 of thegas generator24 also functions as a diffuser. Hereinafter, thecase19 is termed “diffuser”. A plurality ofbolts22 are fixed to thediffuser19. Eachbolt22 extends through a throughhole17 that extends through a bottom portion of thecase16, and anut23 is fastened to a distal end portion of thebolt22 protruding from the outer surface of thecase16. Therefore, thegas generator24 is fixed to thecase16 by thebolts22 and the nuts23.
• An[0142]air bag31 is housed in thecase16, facing the inflator18, as shown in FIGS. 3 and 4. Theair bag31 is folded in a predetermined folding manner described below. Theair bag31 has abag32 and a mountingportion33 that is formed at an opening edge of thebag32. The mountingportion33 has a plurality of insert holes34 that are fitted over thebolts22.
• An[0143]inner bag41 for controlling gas flow is disposed inside theair bag31, in a predetermined folded state. Theinner bag41 has abag42 and a mountingportion43. The mountingportion43 of theinner bag41 also has a plurality of insert holes44 that are fitted over thebolts22.
• When the[0144]gas generator24 is fixed to thecase16 by thebolts22 and the nuts23, theair bag31 and theinner bag41 are also fixed in such a manner that the mountingportions33,43 thereof are fastened by thebolts22 and therefore firmly clamped between thecase16 and thediffuser19. Therefore, theair bag31 and theinner bag41 surround thegas generator24.
• The[0145]bag42 of theinner bag41 is open at opposite ends thereof, as shown in FIG. 1. Each openingedge portion48 is folded so as to form pleats. The pleated or overlapping portions of each openingedge portion48 are adhered to each other. Therefore, each of the two ends of thebag42 has opposideside openings50 that are reduced in size, as shown in FIG. 1.
• The[0146]bag42 of theinner bag41 has acommunication hole47 for communication with an auxiliaryinner bag46 provided as an extended portion of theinner bag41, as shown in FIGS. 1 and 2. The auxiliaryinner bag46 has a generally triangular sectional shape, and is sewed onto the outer surface of thebag42 of theinner bag41 at a position corresponding to thecommunication hole47. The auxiliaryinner bag46 is disposed on a passenger-side face of thebag42, at such a position that when theair bag31 is deployed, a lower face of the auxiliaryinner bag46 abuts on theinstrument panel13 with theair bag31 intervening therebetween. The auxiliaryinner bag46 has in a passenger-side end portion thereof twocommunication holes49 for communication with the interior of theair bag31. The communication holes49 are designed to be smaller than theopposite side openings50 of theinner bag41.
• The procedure of folding the[0147]air bag31 and theinner bag41 when they are housed into thecase16 will be described with reference to FIGS.5-7. In this procedure, theinner bag41 is folded together with theair bag31, so that theinner bag41 is not shown in FIGS.5-7 and will not be described below.
• The[0148]air bag31 is first flattened in a top-to-bottom direction relative to the vehicle as shown in FIG. 5 (in the direction indicated by arrow Z in FIG. 5). Subsequently, opposite end portions of theair bag31 in the fore-to-aft direction (the direction indicated by arrow X) are folded onto a lower surface of theair bag31 into the form of bellows, thereby forming first foldedportions35. Opposite end portions of theair bag31 in the transverse direction relative to the vehicle (direction indicated by arrow Y) are folded into the form of bellows so that the folded portions embrace the mountingportion33 on three sides thereof, as shown in FIG. 7, thereby forming second foldedportions36. The second foldedportions36 are disposed between thegas generator24 and the inner wall surface of thecase16, as shown also in FIG. 3. Central portions of the first foldedportions35 are disposed over thegas generator24 as shown in FIG. 4. When theair bag31 is folded so as to decrease in length in the fore-to-aft directions as shown in FIGS. 4 and 6, the folding is performed so that the amount of sheet of theair bag31 folded is greater in the rearward folded portion (a rightward portion in FIG. 4) of the first foldedportions35 than in the forward folded portion (leftward portion in FIG. 4). In this manner, theair bag31 and theinner bag41 are folded and housed in thecase16 without leaving any substantial space therein.
• The operation and deployment manner of the passenger seat-side[0149]air bag apparatus11 of this embodiment will be described.
• When the[0150]inflator18 of the passenger seat-sideair bag apparatus11 produces gas at the time of an impact on the vehicle, gas is introduced into theinner bag41 through thegas ejecting openings20 of thediffuser19, and temporarily held in theinner bag41. Therefore, the pressure inside the small-capacityinner bag41 increases so that theinner bag41 is inflated and deployed while pressing theair bag31 upward. Then, thecover14, closing the opening of thecase16, is broken along thebreakable groove14aso that thecover14 is forced to open as in a double-hinged door in the transverse directions relative to the vehicle. Gas flows from thebag42 of theinner bag41 into the auxiliaryinner bag46 through thecommunication hole47, so that the auxiliaryinner bag46 is inflated and deployed.
• Immediately, an upper portion of the[0151]bag42 of theinner bag41 presses a portion of theair bag31 against the inner surface of thefront windshield12, and a lower portion of the auxiliaryinner bag46 presses a portion of theair bag31 against an upper surface of theinstrument panel13.
• When the pressure inside the[0152]bag42 of theinner bag41 exceeds a predetermined value, the openingedge portions48 of thebag42 are expanded from the pleated and adhered state so that theopenings50 increase in diameter. Therefore, gas flow into theair bag31 becomes easier.
• The[0153]bag32, folded inside thecase16, is projected from the upper surface of theinstrument panel13 as theinner bag41 is inflated and deployed. In this process, a portion of the first foldedportions35 located over the inflator18 readily protrudes from the upper surface of theinstrument panel13 as indicated by point P1 in FIG. 8 together with the inflation and deployment of theinner bag41, since the inflator18 is disposed in thecase16 in such a posture that the axis of the inflator18 extends in the fore-to-aft direction. Furthermore, since thebag42 of theinner bag41 is provided with the auxiliaryinner bag46, the inflation and deployment of the auxiliaryinner bag46 ensures that the first foldedportions35, disposed over the auxiliaryinner bag46, will be protruded from the upper surface ofinstrument panel13.
• The second folded[0154]portions36 of thebag32 of theair bag31 are folded in on the right and left sides of the inflator18 so as to sandwich theinflator18, as described above. Therefore, when theinner bag41 is inflated and deployed, only small portions of the second foldedportions36 are protruded from the upper surface of theinstrument panel13, and large portions of the second foldedportions36 remain inside thecase16, as indicated by point P2 in FIG. 8. In other words, during an early period of the operation of the passenger seat-sideair bag apparatus11, the deployment of a portion of theair bag31 disposed over the inflator18, that is, over thegas generator24, in the fore-to-aft directions occurs to greater extents than the deployment of theair bag31 in the transverse directions relative to the vehicle.
• Forward and rearward end portions of the first folded[0155]portions35 of theair bag31 become sandwiched between thebag42 of theinner bag41 and thefront windshield12 and between the auxiliaryinner bag46 of theinner bag41 and theinstrument panel13, respectively, while remaining in a folded state, as shown in FIG. 2. Therefore, excessively early deployment of theair bag31 toward the occupant is prevented.
• Subsequently, when the deployment of the[0156]inner bag41 is substantially completed, large amounts of gas flow out of thebag42 of theinner bag41 into theair bag31 through theopposite end openings50 of thebag42 and through the communication holes49 of the auxiliaryinner bag46.
• In this process, the[0157]air bag31 tends to be deployed in the transverse directions relative to the vehicle more easily than in the fore-to-aft directions because, in the assembly process, the transversely opposite end portions of theair bag31 were folded after the opposite end portions thereof in the fore-to-aft directions were folded as described above. Furthermore, since the transverselyopposite side openings50 of thebag42 of theinner bag41 are larger in diameter than the communication holes49 of the auxiliaryinner bag46, greater amounts of gas are supplied throughopposite side openings50 than through the communication holes49, so that theair bag31 is inflated and deployed at greater rates and to greater extents in the transverse directions than in the fore-to-aft directions, as indicated in FIG. 8. Moreover, when the openingedge portions48 of theinner bag41 are expanded from the pleated and adhered state so as to increase their diameters, the inflating deployment of theair bag31 in the transverse directions is further accelerated. Thus, during an intermediate deployment period after theair bag31 of the passenger seat-sideair bag apparatus11 has been protruded upward from theinstrument panel13, the deployment of theair bag31 in the transverse direction relative to the vehicle occurs at greater rates or to greater extents than the deployment thereof in the fore-to-aft directions.
• The first folded[0158]portions35 of theair bag31, sandwiched between theinner bag41 and thefront windshield12 and between the auxiliaryinner bag46 and theinstrument panel13, are also deployed dragging though gaps therebetween. The second foldedportions36 left in thecase16 are pulled out therefrom over theinstrument panel13, dragging through gaps between theinner bag41 and thecase16. The dragging through gaps produces sliding resistance, so that the deploying speed is reduced. Simultaneously, however, gas is supplied into theair bag31 though the communication holes49 of the auxiliaryinner bag46 as well as theopposite side openings50 of theinner bag41. Therefore, theair bag31 is gradually deployed in the fore-to-aft directions, particularly, in the aft direction, as well as in the transverse directions, but at less deploying speeds in the fore-to-aft directions than in the transverse directions.
• When the deployment of the[0159]air bag31 in the transverse directions relative to the vehicle is completed, theair bag31 is immediately inflated and deployed in the fore-to-aft directions to assume a final deployment shape, as indicated in FIG. 10. Prior to the final deployment shape, theair bag31 is deployed toward an occupant at reduced speeds while dragging between thebag42 of theinner bag41 and thefront windshield12 and between the auxiliaryinner bag46 and theinstrument panel13, as described above. In addition, a lower portion of the auxiliaryinner bag46 actively presses the dragging portion of theair bag31 against theinstrument panel13. Therefore, the deploying speed of theair bag31 toward an occupant is reduced without fail.
• The passenger seat-side[0160]air bag apparatus11 of the first embodiment achieves the following advantages.
• When the[0161]inner bag41 is inflated and deployed, thebag42 presses a forward portion of theair bag31 against thefront windshield12, and the auxiliaryinner bag46 presses a rearward portion of theair bag31 against theinstrument panel13. Theair bag31 thus becomes sandwiched between theinner bag41 and thefront windshield12 and between the auxiliaryinner bag46 and theinstrument panel13, so that sliding resistance occurs as theair bag31 is deployed. Therefore, the deploying speed of theair bag31 toward an occupant is reduced, so that strong contact of theair bag31 with the occupant can be avoided if the occupant comes into contact with theair bag31 by inertia or the like before theair bag31 is completely deployed.
• Furthermore, since the[0162]air bag31 is sandwiched between theinner bag41 and thefront windshield12 and between the auxiliaryinner bag46 and theinstrument panel13 during an early deployment period, it is possible to reduce the protrusion of the first foldedportions35 of theair bag31 toward an occupant during the early period. Therefore, it is possible to reduce the danger that if an occupant comes into contact with theair bag31 before theair bag31 is completely deployed, the first foldedportions35, still remaining in a folded state, may contact the occupant.
• While being inflated and deployed, the[0163]air bag31 drags between theinner bag41 and thefront windshield12 and between the auxiliaryinner bag46 and theinstrument panel13. Tension is thereby applied to theair bag31 during the deployment thereof. Therefore, it becomes possible to prevent theair bag31 to be protruded in a nearly packed state.
• During deployment, the auxiliary[0164]inner bag46, attached to thebag42 of theinner bag41, becomes pressed against the upper surface of theinstrument panel13, with a rearward portion of the first foldedportions35 of theair bag31 being sandwiched between the auxiliaryinner bag46 and theinstrument panel13. Therefore, it is possible to reliably prevent the first foldedportions35 of theair bag31 from being protruded toward an occupant during an early period of the deployment of theair bag31.
• Since a lower portion of the auxiliary[0165]inner bag46 actively presses a corresponding portion of theair bag31 against theinstrument panel13, a rearward portion of the first foldedportions35 of theair bag31 will be highly reliably sandwiched between the auxiliaryinner bag46 and theinstrument panel13. Furthermore, since the auxiliaryinner bag46 has a generally triangular shape with a relatively long bottomside when viewed from the side thereof, a sufficiently large area of contact between the auxiliaryinner bag46 and theinstrument panel13 is secured.
• As for the folding of the[0166]air bag31, the opposite end portions thereof in the fore-to-aft directions relative to the vehicle are folded before the transversely opposite end portions thereof are folded. Therefore, when deployed, theair bag31 is first deployed in the transverse directions, and then in the fore-to-aft directions, so that the deploying speed of theair bag31 toward an occupant is reduced. Therefore, even if the occupant comes into contact with theair bag31 before the deployment of theair bag31 is completed, strong contact of theair bag31 with the occupant will be highly reliably prevented. Further, since the entire first foldedportions35 of theair bag31, that is, the end portions thereof in the fore-to-aft directions, are protruded from the upper surface of theinstrument panel13 during an early deployment period, theair bag31 can be smoothly deployed in the transverse directions relative to the vehicle.
• In an early period of the deployment of the[0167]air bag31, the inflating deployment of the auxiliaryinner bag46 ensures that the first foldedportions35 of theair bag31 will be protruded from the upper surface of theinstrument panel13. Therefore, theair bag31 can be smoothly deployed in the transverse directions relative to the vehicle.
• The two[0168]communication holes49 for communication with the interior of theair bag31 are formed in an occupant-side end portion of the auxiliaryinner bag46. Therefore, while theair bag31 is being inflated and deployed in the transverse directions, theair bag31 is gradually inflated and deployed in the fore-to-aft directions relative the vehicle. Consequently, it is possible to highly reliably prevent strong contact of theair bag31 with an occupant even if the occupant comes into contact with theair bag31 before the complete deployment of theair bag31.
• The[0169]air bag31 is folded so that second foldedportions36 of theair bag31, that is, the transversely opposite-side folded portions, will not interfere with a central portion of theair bag31. Therefore, in an early deployment period, the entire first foldedportions35, that is, the opposite-side folded portions in the fore-to-aft directions, are readily protruded from the upper surface of theinner bag41 as theinner bag41 is inflated and deployed. As a result, theair bag31 will be smoothly deployed in the transverse directions relative to the vehicle.
• The[0170]inflator18 is disposed in thecase16 so that the axis of the inflator18 lies in the fore-to-aft directions, and the first foldedportions35 of theair bag31, that is, the opposite-end folded portions in the fore-to-aft directions, are located over theinflator18. Therefore, in an early period of the deployment of theair bag31, the substantially entire first foldedportions35 will be reliably protruded from the upper surface of theinstrument panel13 as theinner bag41 is inflated and deployed. Then, theair bag31 will be smoothly deployed in the transverse directions relative to the vehicle.
• The[0171]air bag31 and theinner bag41 are housed in thecase16 without any substantial free space therein. Therefore, this embodiment achieves compact containment of theair bag31 in thecase16 while retaining the air-bag deploying performance as described above.
• The[0172]cover14 breaks open in the transverse directions as theinner bag41 is inflated and deployed. Therefore, thecover14 does not interfere with the auxiliaryinner bag46 of theinner bag41, so that the auxiliaryinner bag46 will be reliably deployed rearward into a downwardly pressing state as described above. Furthermore, thecover14 is reliably prevented from contacting an occupant when it is broken open.
• The amount of gas to be supplied from the[0173]inner bag41 into theair bag31 per unit time can be adjusted by changing the diameter of the opposite side openings of theinner bag41. Thereby, the inflating-deploying speed of theair bag31 can be adjusted. Consequently, it is possible to adjust the restraint performance on an occupant in accordance with types of vehicles.
• The first embodiment may also be modified as follows.[0174]
• The shape of the auxiliary[0175]inner bag46 may also be a shape other than a triangular shape in a side view, for example, a circular shape, an elliptical shape, rectangular shape and the like.
• Although in the first embodiment, the[0176]bag42 is formed separately from theinner bag41 and then sewed onto theinner bag41, the auxiliaryinner bag46 and theinner bag41 may also be formed together.
• The auxiliary[0177]inner bag46 may also be adhered to thebag42 instead of being sewed thereto.
• Although in the foregoing embodiment, the opening[0178]edge portions48 of theinner bag41 are pleated and adhered in order to reduce the diameter ofopposite side openings50 at the transversely opposite ends of theinner bag41, the pleats of the openingedge portions48 may instead be sewed together using a thread that breaks when the internal pressure of theinner bag41 reaches or exceeds a predetermined value (tear seam).
• The communication holes[0179]49 of the auxiliaryinner bag46 may be changed in position to, for example, side surfaces of the auxiliaryinner bag46, upper or lower surfaces thereof, or the like.
• Second Embodiment[0180]
• A second embodiment of the invention will be described with reference to FIGS.[0181]11-24. Portions of the second embodiment comparable to those of the first embodiment are represented by comparable reference characters in the drawings, and will not be described again. In each of the embodiments described below, thecover14 for covering an air bag apparatus for a passenger seat is substantially the same as that in the first embodiment, and is not shown in the drawings.
• Referring first to FIGS. 11 and 12, an[0182]air bag31 has amouth portion61 that is provided between abag32 and a mountingportion33.
• An[0183]inner bag41 also has amouth portion71 that is provided between abag42 and a mountingportion43 for introducing gas from an inflator18 into theinner bag41. Theinner bag41 further has astrap72 as a restriction member. Each of an upper surface and a lower surface of thebag42 has twocommunication holes73 for supplying gas into theair bag31. The mountingportion43 and thestrap72 have a plurality of insert holes74 and75, respectively.
• In the second embodiment, the[0184]inflator18 and adiffuser19, which form agas generator24, are disposed so that the axis thereof lies in the transverse direction relative to the vehicle, not in the fore-to-aft direction as in the first embodiment.
• The construction of the[0185]inner bag41 will be described following the production procedure thereof.
• First, a[0186]left face cloth100 and alower face cloth77 are placed on each other in alignment as shown in FIG. 13, and distal end portions of the upper andlower face cloths76,77 are placed over an end of thestrap72. While being held in this position, the upper andlower face cloths76,77 and thestrap72 are sewed together so as to form aseam78. Subsequently, theleft face cloth100 and thelower face cloth77 are turned inside out as shown in FIG. 14, with the distal end portion thereof being folded inside, in such a manner that the insert holes74 of the mountingportion43 of theinner bag41 coincide with the insert holes75 of thestrap72.
• The[0187]inner bag41 is then inserted into theair bag31 as shown in FIGS. 11 and 15. The upper andlower face cloths76,77 of the mountingportion43 of theinner bag41 are sewed to the upper and lower face cloths of the mountingportion33 of theair bag31, respectively, so as to form seams79. In this sewing process, an end portion of thestrap72 is simultaneously sewed to the upper or lower face cloth of the mountingportion33 of theair bag31 on theseam79.
• The thus-sewed[0188]inner bag41 is folded together with theair bag31. The folded bag unit is then placed in thecase16. The procedure for placing theair bag31 and theinner bag41 in thecase16 and fixing them to thecase16 will be described below with reference to FIGS.16-20.
• First, the[0189]bag32 and themouth portion61 of theair bag31 are respectively flattened so that theentire air bag31 has a profile of a letter “T” as shown in FIGS. 16 and 17. Subsequently, the transverselyopposite end portions32dof thebag32 of theair bag31, protruding from the width of the inflator18 in the transverse directions relative to the vehicle, are alternately folded back to a central portion of theair bag31 so that thebag32 is formed into the shape of a belt elongated in the fore-to-aft directions relative to the vehicle and having a sectional shape of bellows as shown in FIG. 19.
• In this folding process, the[0190]inner bag41 is placed and folded in aforward portion32aof thebag32, so that theinner bag41 extends through themouth portion61 into theforward portion32aof theair bag31, as can be seen in FIG. 20 (theinner bag41 is indicated by a broken line). After that, theforward portion32aof thebag32 of theair bag31 is folded into generally the shape of a squared roll by rolling it counterclockwise in a view from the left side of the vehicle, as shown in FIG. 20. Arearward portion32bof thebag32 is folded into generally the shape of a squared roll by rolling it clockwise in a view from the left side of the vehicle.
• The mounting[0191]portion33 of theair bag31, and the mountingportion43 of theinner bag41, and the end portion of thestrap72 are wrapped around thegas generator24, and thebolts22 provided on thegas generator24 are inserted into the insert holes34,74,75, as shown in FIG. 20. While maintained in this state, thegas generator24 and theair bag31 are placed into thecase16 so that thebolts22 of thegas generator24 are inserted intoholes17 of thecase16. By subsequently fastening the nuts23 to thebolts22, thegas generator24 and theair bag31 are positioned and fixed in thecase16.
• When the[0192]air bag31 and theinner bag41 are thus housed in thecase16, themouth portion61 of theair bag31 is located extending in a middle portion within thecase16, as shown. Acentral portion32cof thebag32 of theair bag31 tautly extends in a middle portion of the opening of the case16 (facing the plane of the opening). Theforward portion32aand therearward portion32bof thebag32 of theair bag31 are folded and disposed between themouth portion61 and the opposite inner surfaces of thecase16. Theinner bag41 is folded and contained in theforward portion32aof thebag32.
• When gas is generated in the[0193]gas generator24 of the passenger seat-sideair bag apparatus11 of this embodiment, gas flows out of thegas ejecting openings20 of thediffuser19 into thebag42 of theinner bag41 through themouth portion71. Since themouth portion71 is flattened or squeezed as shown in FIG. 20, gas dwells at the entrance to themouth portion71 and therefore builds up pressure in such a manner that themouth portion71 would be forced to protrude upward from the upper surface of theinstrument panel13. However, themouth portion71 is not actually forced to protrude upward, since themouth portion71 extends from the inflator18 without slack.
• Instead, the[0194]mouth portion71 of theinner bag41 is expanded in breadth in the directions indicated by arrows in FIG. 21, by the high-pressure gas introduced thereinto from thegas generator24, thereby forming a guide passage through themouth portion71. Themouth portion61 of theair bag31 is expanded together with themouth portion71 of theinner bag41, so that theforward portion32aand therearward portion32bof thebag32, folded and contained between themouth portion61 and the inner opposite surfaces of thecase16, are pressed against the corresponding inner surfaces. Immediately, gas flows through the guide passage of themouth portion71 into thebag42 of theinner bag41, thereby inflating thebag42. Therefore, thebag32 of theair bag31 is deployed in the following manner. That is, only, thecentral portion32cis initially expanded so that thecentral portion32cis deployed while being tightly drawn without a crease allowed therein, as shown in FIG. 22.
• In this manner, gas introduced into the[0195]bag42 of theinner bag41 inflates thebag42 and, in addition, flows out into thebag32 of theair bag31 through the communication holes73. However, due to the contraction flow resistance caused when gas flows through the communication holes73, the pressure inside theinner bag41 remains higher than that in theair bag31. Therefore, theinner bag41 is first inflated to a final deployment state as shown in FIG. 22.
• In the process of inflation of the[0196]inner bag41, thestrap72 restricts the expansion length of a central portion of thebag42 toward an occupant. Therefore, thebag42 of theinner bag41 is deployed into a shape that is long in the transverse directions and vertical directions relative to the vehicle and short in the fore-to-aft directions. As a result, the deployedbag42 of theinner bag41 presses portions of thebag32 of theair bag31 against thefront windshield12 and theinstrument panel13.
• When gas is further introduced into the[0197]bag32 of theair bag31 through the communication holes73 of theinner bag41, the tension in thecentral portion32cof thebag32, now facing rearward, increases so that theforward portion32aand therearward portion32bof thebag32 are progressively pulled out of thecase16 and deployed, as shown in FIG. 23. Since theforward portion32aand therearward portion32bof thebag32 are being pressed against the inner surfaces of thecase16 due to the expansion of themouth portion61 of theinner bag41 as described above, sliding resistance occurs between the forward andrearward portions32a,32band the corresponding inner surfaces of thecase16 when the portions are pulled out. Therefore, the deploying speed of the forward andrearward portions32a,32bof thebag32 is considerably reduced.
• Since the[0198]forward portion32aand therearward portion32bof thebag32 of theair bag31 are also being pressed against thefront windshield12 and theinstrument panel13, respectively, due to the inflation of thebag42 of theinner bag41, sliding resistance also occurs therebetween so that the deploying speed of theforward portion32aand therearward portion32bof thebag32 is further reduced.
• The passenger seat-side[0199]air bag apparatus11 of the second embodiment achieves the following advantages.
• When the[0200]inner bag41 is inflated and deployed, theleft face cloth100 of theinner bag41 presses a portion of theair bag31 against thefront windshield12, and thelower face cloth77 of theinner bag41 presses a portion of theair bag31 against theinstrument panel13. Therefore, theair bag31 is thereby sandwiched between theinner bag41 and thefront windshield12 or theinstrument panel13, so that sliding resistance occurs when theinstrument panel13 is deployed. Consequently, the deploying speed of theair bag31 toward an occupant is reduced so that strong contact of theair bag31 with the occupant can be substantially prevented even if the occupant comes into contact with theair bag31 before the deployment of theair bag31 is completed.
• Since the[0201]air bag31 becomes sandwiched between theinner bag41 and thefront windshield12 or theinstrument panel13 during an early period of the deployment of theair bag31, the passenger seat-sideair bag apparatus11 of the embodiment significantly reduces the danger that the roll-like folded portions of theforward portion32aand therearward portion32bof thebag32 of theair bag31 may protrude toward an occupant during the early period. Therefore, the embodiment significantly reduces the danger that the folded forward orrearward portion32aor32bof thebag32 of theair bag31 may contact an occupant even if the occupant comes into contact with theair bag31 before it is completely deployed.
• When the inflator[0202]18 is operated, theinner bag41 is inflated so that theforward portion32aof theair bag31 is deployed to a predetermined extent prior to other portions of theair bag31. Due to gas subsequently supplied through the communication holes73 of theinner bag41, the other portions of theair bag31 are inflated and deployed from the folded state while being tightly drawn. Therefore, no crease is formed in thecentral portion32cof thebag32 of theair bag31.
• The[0203]inner bag41 contains thestrap72 provided as a restriction member for restricting the inflation of a central portion of theinner bag41 to a predetermined extent. Due to thestrap72, the upper and lower portions of theinner bag41 are inflated to greater extents than the central portion thereof, so that theforward portion32aand therearward portion32bof theair bag31 are reliably pressed against thefront windshield12 and theinstrument panel13, respectively. Therefore, the deploying speed of theforward portion32aand therearward portion32bof theair bag31 is considerably reduced. Consequently, strong contact of theair bag31 with an occupant can be substantially prevented even if the occupant comes into contact with theair bag31 while theair bag31 is being deployed.
• The inflation of the central portion of the[0204]inner bag41 is restricted to a predetermined amount by thestrap72. Therefore, even if an occupant is out of the proper sitting position and contacts theair bag31 before it is completely deployed, this embodiment considerably reduces the danger that theinner bag41 may strike the occupant with theair bag31 intervening therebetween.
• By changing the diameter of the communication holes[0205]73, the amount of gas supplied from theinner bag41 into theair bag31 per unit time can be adjusted and, therefore, the deploying speed of theair bag31 can be adjusted. Consequently, this embodiment makes it possible to adjust the restraining performance on an occupant in accordance with types of vehicles and the like.
• Third Embodiment[0206]
• A third embodiment of the invention will be described with reference to FIGS. 25 and 26.[0207]
• In the third embodiment, the[0208]strap72 of theinner bag41 has been formed as an extension of a distal end portion of theleft face cloth100 or thelower face cloth77, as shown in FIG. 25. In the production of theinner bag41, after theupper face cloth76 and thelower face cloth77 are sewed together so as to form aseam78, theupper face cloth76 and thelower face cloth77 are turned inside out so that the distal end portions thereof are folded inside.
• After that, the[0209]inner bag41 is inserted into theair bag31 in substantially the same manner as in the second embodiment, and the upper and lower faces of the mountingportion43 of theinner bag41 are sewed to the upper and lower faces of the mountingportion33 of theair bag31, respectively, so as to formseams79, as shown in FIG. 26. In this sewing process, a distal end of thestrap72 is simultaneously sewed to the upper or lower face of the mountingportion33 of theair bag31 on theseam79.
• Therefore, the third embodiment achieves not only substantially the same advantages as achieved by the second embodiment, but also the following advantages.[0210]
• In the third embodiment, the[0211]strap72 of theinner bag41 is formed together with one of theupper face cloth76 and thelower face cloth77. Therefore, there is no need to align thestrap72 to the distal end portions of theupper face cloth76 and thelower face cloth77 when the upper andlower face cloths76,77 are sewed together so as to form theseam78 in the production process of theinner bag41. In this manner, this embodiment simplifies the sewing process.
• Fourth Embodiment[0212]
• A fourth embodiment of the invention will be described with reference to FIGS. 27 and 28.[0213]
• In this embodiment, the[0214]strap72 of theinner bag41 has been formed as an extension of a distal end portion of each of theupper face cloth76 and thelower face cloth77, as shown in FIG. 27. In the production of theinner bag41, after theupper face cloth76 and thelower face cloth77 are sewed together so as to form aseam78, theupper face cloth76 and thelower face cloth77 are turned inside out so that the distal end portions thereof are folded inside.
• After that, the[0215]inner bag41 is inserted into theair bag31 in substantially the same manner as in the second and third embodiments, and the upper and lower faces of the mountingportion43 of theinner bag41 are sewed to the upper and lower faces of the mountingportion33 of theair bag31, respectively, so as to formseams79, as shown in FIG. 28. In this sewing process, a distal end of thestrap72 is simultaneously sewed to the upper or lower face of the mountingportion33 of theair bag31 on theseam79. In the fourth embodiment, thestrap72 of theinner bag41 has a double-layer structure.
• Therefore, the third embodiment achieves not only substantially the same advantages as achieved by the second or third embodiment, but also the following advantages.[0216]
• In the fourth embodiment, the[0217]strap72 has a double-layer structure, so that the tensile strength of thestrap72 is enhanced. Therefore, the embodiment substantially eliminates the danger that thestrap72 may be broken by gas pressure when thebag42 of theinner bag41 is inflated and deployed toward an occupant by gas generated by theinflator18.
• Furthermore, since the[0218]upper face cloth76 and thelower face cloth77 are identical to each other, there is no need to cut the cloths in separate processes. Therefore, the cutting process can be simplified, and the production of theinner bag41 is made easier.
• The second through fourth embodiments may be modified as follows.[0219]
• The number of communication holes[0220]73 may be changed to three or less or to five or greater.
• Communication holes may also be formed simply by leaving portions of the outer periphery of the[0221]upper face cloth76 and thelower face cloth77 unsewed.
• The[0222]upper face cloth76 and thelower face cloth77 may be joined by using adhesive instead of sewing.
• Any of the aforementioned modifications will facilitate the production of the[0223]inner bag41.
• In the second through fourth embodiments, the[0224]upper face cloth76 and thelower face cloth77 of theinner bag41 may also be formed of a single cut cloth having an integrated shape as shown in FIG. 29 (wherein the cut cloth is based on the second embodiment). With this cut cloth, theinner bag41 can easily be formed by folding it so that the upper andlower face cloths76,77 face each other, and by sewing them along the outer periphery thereof except for the folded portion.
• In the fourth embodiment, the[0225]strap72 may have agas passage hole72aas indicated by an imaginary line (two-dot line) in FIG. 27. This modification increases the freedom of gas flow between the side of theupper face cloth76 and the side of thelower face cloth77.
• Fifth Embodiment[0226]
• A fifth embodiment of the invention will be described with reference to FIGS.[0227]30-39.
• In the fifth embodiment, the[0228]strap72 disposed in aninner bag41 is shifted toward a lower side of theinner bag41 so that an upper portion of thebag42 of theinner bag41 will be inflated to a greater size than the lower portion thereof, as shown in FIGS.37-39. To produce thisinner bag41, a distal end of thestrap72 is positioned to a portion of thelower face cloth77 toward the center thereof, instead of the distal end thereof, as shown in FIG. 31. While being held in this position, thestrap72 is sewed to thelower face cloth77 so as to form aseam80. Subsequently, thelower face cloth77 and theupper face cloth76 are sewed together so as to form aseam78 as shown in FIG. 32. The upper andlower face cloths76,77 are then turned inside out so that distal end portions thereof are folded inside, as shown in FIG. 33.
• After the[0229]inner bag41 is inserted into theair bag31 as in the second embodiment, the upper and lower faces of the mountingportion43 of theinner bag41 are sewed to the upper and lower faces of the mountingportion33 of theair bag31 so as to formseams79, as shown in FIG. 34. In this sewing process, an end of thestrap72 is simultaneously sewed to the upper face of the mountingportion33 of theair bag31 on theseam79. Therefore, thestrap72 inside theinner bag41 is shifted to the side of thelower face cloth77, instead of being disposed at an intermediate position between the upper andlower face cloths76,77.
• The Passenger seat-side[0230]air bag apparatus11 of this embodiment is installed in an upper portion of theinstrument panel13 as shown in FIG. 35. When gas is produced from the inflator18, theinner bag41 is inflated and, subsequently, theair bag31 is deployed, substantially in the same manner as in the second embodiment. That is, themouth portion71 of theinner bag41 is first expanded, as shown in FIG. 36, so that theforward portion32aand therearward portion32bof thebag32 of theair bag31 are pressed against the opposite internal surfaces of thecase16. As theinner bag41 is deployed, thecentral portion32cof thebag32 starts to be deployed.
• Subsequently, the[0231]bag42 of theinner bag41 is inflated to a final deployment shape as shown in FIG. 37 so that thebag32 of theair bag31 are pressed against thefront windshield12 and theinstrument panel13. Since thestrap72 inside theinner bag41 is shifted to the side of thelower face cloth77 of theinner bag41, the upper portion of thebag42 of theinner bag41 is inflated to a greater size than the lower portion thereof. As a result, the area in theforward portion32aof thebag32 of theair bag31 pressed against thefront windshield12 is larger than the area in therearward portion32bthat is pressed against theinstrument panel13.
• As more gas is introduced into the[0232]air bag31 through the communication holes73 of theinner bag41, theforward portion32aand therearward portion32bof thebag32 of theair bag31 are progressively pulled out of thecase16 as shown in FIG. 38 until theair bag31 is deployed to a final deployment shape indicated by a solid line in FIG. 39. Since face areas of thebag32 of theair bag31 are pressed against thefront windshield12 and theinstrument panel13 by thebag42 of theinner bag41 during the deployment of theair bag31, sliding resistance occurs therebetween so that the deploying speed of thebag32 is reduced. The deploying speed of theforward portion32aof thebag32 is particularly effectively reduced since the area in theforward portion32apressed against thefront windshield12 by thebag42 is relatively large.
• Therefore, the fifth embodiment achieves substantially the same advantages as achieved by the second embodiment and, in addition, the following advantages.[0233]
• In this embodiment, the[0234]strap72 is shifted from a central position inside theinner bag41 so that the upper portion of theinner bag41 will be inflated to a greater size than the lower portion thereof. Therefore, even if thefront windshield12 is far apart from theinstrument panel13, the embodiment ensures that a large area in theforward portion32aof theair bag31 will be pressed against thefront windshield12 by thebag42 of theinner bag41, thereby effectively reducing the deploying speed of the upper portion of theair bag31.
• The fifth embodiment may also be modified as follows.[0235]
• The[0236]lower face cloth77 of theinner bag41 may be shorter in the fore-to-aft direction than theupper face cloth76. The upper andlower face cloths76,77 are sewed together, with the mountingportions33 thereof being aligned to each other. Thestrap72 is provided as a portion extending from the distal end of the upper andlower face cloths76,77, so that the upper and lower portions of thebag42 divided by the seam and thestrap72 will be inflated to different sizes.
• Sixth Embodiment[0237]
• A sixth embodiment of the invention will be described with reference to FIGS.[0238]40-43.
• In the sixth embodiment, the[0239]upper face cloth76 of thebag42 of theinner bag41 as in the fifth embodiment has forward communication holes81 in addition to the right and left communication holes73, as shown in FIG. 40. When gas flows into theinner bag41 from the inflator18, gas is supplied into theair bag31 not only through the communication holes73 but also through the forward communication holes81. Gas through the forward communication holes81 is mainly supplied to a forward lower portion of theair bag31.
• Therefore, when the[0240]inner bag41 is inflated by gas from the inflator18, thebag32 of theair bag31 is inflated forward downward by gas supplied through the forward communication holes81 as shown in FIG. 41-43, so that an increased portion of thebag32 of theair bag31 is pressed into a corner defined by thefront windshield12 and theinstrument panel13 and therefore pressed against thefront windshield12 and theinstrument panel13 by gas supplied thereinto. Therefore, the sliding resistance caused when theforward portion32aof thebag32 of theair bag31 is pulled out of thecase16 is further increased. Consequently, the deploying speed of theair bag31 is further reduced.
• Therefore, in addition to substantially the same advantages as achieved by the second through fifth embodiments, the sixth embodiment achieves the following advantages.[0241]
• In the sixth embodiment, the[0242]inner bag41 has the forward communication holes81 for letting gas out in a forward downward direction, so that theair bag31 is deployed also in a forward direction. Therefore, theair bag31 is also pressed, at a forward side, against thefront windshield12 and theinstrument panel13, thereby further reducing the deploying speed of theair bag31.
• The sixth embodiment may be modified in the following manners.[0243]
• The number of forward communication holes[0244]81 may be reduced to one or increased to three or greater.
• A dust portion may be provided extending forward downward from one of the forward communication holes[0245]81.
• This modification ensures that gas will be delivered into a forward downward portion of the[0246]air bag31.
• Seventh Embodiment[0247]
• A seventh embodiment of the invention will be described with reference to FIGS.[0248]44-53.
• In the seventh embodiment, the[0249]inner bag41 is formed by sewing theleft face cloth100 and theright face cloth101 along aseam78 as shown in FIGS. 45 and 46. In this embodiment, theleft face cloth100 and theright face cloth101 do not actually face upward and downward when disposed in the passenger-sideair bag apparatus11, but the terms are still used to separately refer to the two cloths of thebag42 of theinner bag41. Thebag42 of theinner bag41 has an upper protrudedportion82 and alower protruded portion83 that are protruded upward and downward (when in the passenger seat-side air bag apparatus11). A distal end of the bag42 (that faces rearward when inflated) connecting between the upper and lower protrudedportions82 and83 is substantially straight. The upper protrudedportion82 is larger than thelower protruded portion83. The mountingportion43 of each of the left andright face cloths100,101 has acutout43a.
• In the folding process, the[0250]inner bag41 is folded separately from theairbag31 in the following manner. First, theleft face cloth100 is folded, as indicated in FIG. 45, along folding lines La1, La2 in a channel folding manner, and along folding lines Lb1, Lb2, Lb3 in a ridge folding manner. Simultaneously, theright face cloth101 is folded, as indicated in FIG. 46, along folding lines La3, La4 in a channel folding manner, and along folding lines Lb4, Lb5, Lb6 in a ridge folding manner. Theinner bag41 is thereby folded into a shape as shown in FIG. 47. Subsequently, the upper protrudedportion82 is channel-folded along a folding line La5 so as to form a shape as shown in FIG. 48. When theinner bag41 is thus folded, theedge43bof eachcutout43aforms rightward or leftward outer edge of the mountingportion43, and theseam78 extends through substantially the middle of the mountingportion43. In this folded state, the upper protrudedportion82 and thelower protruded portion83 vertically overlap each other.
• When the thus-folded[0251]bag42 is inflated and deployed, theleft face cloth100 and theright face cloth101 come to face in the transverse directions relative to the vehicle. Therefore, thebag42 is inflated and deployed mainly upward and downward. Since the upper protrudedportion82 is larger in size than thelower protruded portion83, thebag42 becomes larger in an upper portion than in a lower portion thereof when inflated. Further, since the distal end of thebag42 that faces rearward when thebag42 is deployed is substantially straight, thebag42 does not protrude toward an occupant to a significant extent when it is deployed.
• While maintained in this folded state, the[0252]inner bag41 is inserted into theair bag31 as shown in FIG. 44. The upper and lower faces of the mountingportion43 of theinner bag41 are sewed to the upper and lower faces of the mountingportion33 of theair bag31, respectively, along seams79. After theair bag31 is folded in substantially the same procedure as in the second embodiment, theair bag31 is placed together with the inflator18 inside thecase16. The passenger seat-sideair bag apparatus11 is installed in an upper portion inside theinstrument panel13 of a vehicle as shown in FIG. 49.
• When gas is produced from the[0253]inflator18 of the passenger seat-sideair bag apparatus11 of this embodiment, theinner bag41 is first inflated and, after that, theair bag31 is deployed, as in the second embodiment. That is, themouth portion71 of theinner bag41 is first expanded as shown in FIG. 50 so that the foldedforward portion32aand the foldedrearward portion32bof thebag32 of theair bag31 are pressed against the opposite inner surfaces of thecase16. As theinner bag41 is deployed from this state, thecentral portion32cof thebag32 of theair bag31 starts to be deployed.
• Subsequently, the[0254]bag42 of theinner bag41 is inflated to a final deployment shape as shown in FIG. 51 so that portions of thebag32 of theair bag31 are pressed against thefront windshield12 and theinstrument panel13. Owing to the upper protrudedportion82 and thelower protruded portion83 of thebag42 of theinner bag41, thebag42 is inflated to great extents mainly in upward and downward directions. Further, since the upper protrudedportion82 is designed to have a greater amount of protrusion than thelower protruded portion83, thebag42 is inflated and deployed to a greater extent at an upper side than at a lower side thereof. As a result, a relatively large area in theforward portion32aof thebag32 of theair bag31 is pressed against thefront windshield12.
• As more gas is introduced into the[0255]air bag31 through the mountingportion43 of theinner bag41, thebag32 and therearward portion32bof thebag32 of theair bag31 is progressively pulled out of thecase16 as shown in FIG. 52 until thebag32 of theair bag31 is deployed into a final deployment shape as shown in FIG. 53. Since portions of thebag32 are pressed against thefront windshield12 and theinstrument panel13, sliding resistance occurs therebetween as thebag32 is deployed, so that the deploying speed of thebag32 is reduced. In particular, the deploying speed of theforward portion32aof thebag32 is effectively reduced since a relatively large area in theforward portion32aof thebag32 is pressed against thefront windshield12.
• Therefore, in addition to substantially the same advantages of the second embodiment, the seventh embodiment further achieves the following advantages.[0256]
• In the seventh embodiment, the[0257]inner bag41 has the upper protrudedportion82 and thelower protruded portion83, so that theinner bag41 is deployed mainly in upward and downward directions. Therefore, there is no need to provide inside the inner bag41 a restriction member, such as thestrap72, for restricting the amount of inflation of a central portion of theinner bag41, so that the construction of theinner bag41 can be simplified. Furthermore, since the inflation of the upper protrudedportion82 and thelower protruded portion83 of theinner bag41 more effectively presses theforward portion32aand therearward portion32bof theair bag31 against thefront windshield12 and theinstrument panel13, the deploying speed of theair bag31 can be more effectively reduced.
• In this embodiment, the upper protruded[0258]portion82 of theinner bag41 is designed to be inflated to a greater size than thelower protruded portion83. Therefore, even if theair bag31 and thefront windshield12 are far apart from each other, it is possible to secure a large area of an upper portion of theair bag31 that is pressed against thefront windshield12. Consequently, the deploying speed of an upper portion of theair bag31 can be effectively reduced.
• Eighth Embodiment[0259]
• An eighth embodiment of the invention will be described with reference to FIGS.[0260]54-57.
• Referring to FIG. 54, the[0261]bag42 of theinner bag41 in the eighth embodiment has a gourd-like sectional shape formed by afirst inflating portion84 and asecond inflating portion85 each having a generally ellipsoid shape. Thesecond inflation portion85 is disposed on top of the first inflatingportion84, and communicates with the first inflatingportion84. Thesecond inflating portion85 has in transversely opposite end portions thereof a pair of communication holes86 for supplying gas therefrom into theair bag31. Thefirst inflating portion84 is larger than thesecond inflating portion85.
• This[0262]inner bag41 is disposed in theair bag31. Theinner bag41 and theair bag31 are fixed in thecase16 and folded therein as in the second embodiment.
• When gas is produced from the[0263]inflator18 of the passenger seat-sideair bag apparatus11 of this embodiment, the first inflatingportion84 of thebag42 of theinner bag41 is first inflated and deployed as shown in FIG. 55 and, subsequently, thesecond inflating portion85 is inflated and deployed as shown in FIG. 56. As the deployment of theinner bag41 approaches completion, gas is supplied into theair bag31 through the communication holes86 of thesecond inflating portion85 and, therefore, theair bag31 starts to be deployed.
• When the inflating deployment of the[0264]inner bag41 approaches completion, thesecond inflating portion85 presses a portion of theair bag31 against thefront windshield12 and, on the other hand, the first inflatingportion84 presses a portion of theair bag31 against theinstrument panel13.
• As more gas is introduced into the[0265]bag32 of theair bag31 through the communication holes86 of theinner bag41, thebag32 of theair bag31 is inflated and deployed toward an occupant. In this process, thebag32 of theair bag31 is deployed dragging between thebag42 of theinner bag41 and thefront windshield12 and between thebag42 and theinstrument panel13, so that sliding resistance occurs therebetween, significantly reducing the deploying speed of theforward portion32aand therearward portion32bof thebag32.
• Furthermore, since the[0266]bag42 of theinner bag41 has a gourd-like sectional shape formed by the ellipsoidal first andsecond inflating portions84,85, thebag42 is unlikely to collapse while gas is being supplied into theair bag31 through the communication holes86 of thebag42. More specifically, thebag42 receives tension from gas therein in directions as indicated by arrows in FIG. 56, so that the tensions on the first andsecond inflating portions84,85 repel each other at a constricted portion therebetween and therefore resist collapse in vertical directions. Consequently, thebag42 of theinner bag41 continues pressing portions of thebag32 of theair bag31 against thefront windshield12 and theinstrument panel13 until thebag32 of theair bag31 is completely inflated and deployed as shown in FIG. 57. Therefore, the deploying speed of theair bag31 is further effectively reduced. Moreover, since the first inflatingportion84 is larger than thesecond inflating portion85, the first inflatingportion84 makes a firm base so that thebag42 remains substantially fixed in position thereby allowing stable inflation and deployment.
• Therefore, in addition to substantially the same advantages as achieved by the second embodiment, the eighth embodiment further achieves the following advantages.[0267]
• The[0268]bag42 of theinner bag41 resists collapsing after the inflation and deployment there has been completed. Therefore, thebag32 of theair bag31 is dragged between thebag42 of theinner bag41 and thefront windshield12 and between thebag42 and theinstrument panel13 during substantially the entire period from the start to the completion of the inflating deployment of thebag32. Consequently, the passenger seat-sideair bag apparatus11 of this embodiment further effectively reduces the deploying speed of theair bag31, and substantially prevents strong contact of theair bag31 with an occupant even if the occupant comes into contact with theair bag31 before it is completely deployed.
• The[0269]bag42 of theinner bag41 has a gourd-like sectional shape formed by the arrangement of the upper and lowerellipsoidal inflating portions84,85, thereby achieving an increased vertical dimension. The increased vertical length of thebag42 ensures thatbag42 will be pressed against thefront windshield12 even if thefront windshield12 is far apart from theinstrument panel13, that is, if the slope angle θ of thefront windshield12 as indicated in FIG. 57 is great. Therefore, the passenger seat-sideair bag apparatus11 of this embodiment reliably reduces the deploying speed of theair bag31 even when applied to a vehicle type in which the slope angle θ of thefront windshield12 is great so that thefront windshield12 stands nearly vertical.
• Since the first inflating[0270]portion84 of thebag42 of theinner bag41 is larger than thesecond inflating portion85, thebag42 will be stably inflated and deployed so that sliding resistance will be reliably applied to theair bag31.
• The eighth embodiment may be modified as follows.[0271]
• Although in the eighth embodiment, the first inflating[0272]portion84 is larger than thesecond inflating portion85, the first inflatingportion84 may be as large as thesecond inflating portion85. Further, thesecond inflating portion85 may be larger than the first inflatingportion84.
• Although in the foregoing embodiment, the[0273]inner bag41 has a gourd-like sectional shape formed by the upper and lower inflating portions, theinner bag41 may also be formed by three or more inflating portions arranged vertically.
• Ninth Embodiment[0274]
• A ninth embodiment of the invention will be described with reference to FIGS.[0275]58-61.
• In the ninth embodiment, the[0276]bag42 of theinner bag41 is formed so as to be inflated into a vertically elongated shape as indicated by a two-dot line in FIGS. 60 and 61 if it is not restricted. Anupper portion42aof thebag42 has in transversely opposite portions thereof communication holes86 for supplying gas into theair bag31. Thebag42 is designed so that the distance between the upper andlower portions42aand42bis greater than the distance between thefront windshield12 and theinstrument panel13 measured at the position of deployment of thebag42. Therefore, the actual shape of thebag42 when deployed is a generally crescent shape in which theupper portion42aand thelower portion42bare curved along thefront windshield12 and theinstrument panel13, respectively, as shown in FIGS. 58, 60 and61.
• The[0277]inner bag41 formed in this manner is disposed in theair bag31. Theinner bag41 and theair bag31 are fixed in thecase16 and folded therein as in the second embodiment.
• When gas is produced from the[0278]inflator18 of the passenger seat-sideair bag apparatus11 of this embodiment, theinner bag41 is inflated in such a manner that theupper portion42aand thelower portion42bof thebag42 protrude from the upper surface of theinstrument panel13, as shown in FIG. 60. As the deployment of theinner bag41 approaches completion, gas is supplied from thebag42 into theair bag31 through the communication holes86 so that theair bag31 starts to be deployed. Therefore, in the passenger seat-sideair bag apparatus11 of this embodiment, theinner bag41 is first inflated and, subsequently, theair bag31 is deployed, as in the second embodiment.
• When the inflating deployment of the[0279]inner bag41 is substantially completed, theupper portion42aof thebag42 presses a portion of theair bag31 against thefront windshield12, and thelower portion42bpresses a portion of theair bag31 against theinstrument panel13.
• When more gas is introduced into the[0280]bag32 of theair bag31 through the communication holes86 from theinner bag41 in a completely deployed state, thebag32 of theair bag31 becomes inflated and deployed toward an occupant side. In this process, thebag32 of theair bag31 is deployed dragging between thebag42 of theinner bag41 and thefront windshield12 and between thebag42 and theinstrument panel13, so that sliding resistance occurs thereby significantly reducing the deploying speed of theforward portion32aand therearward portion32bof thebag32 of theair bag31. Furthermore, since thebag42 of theinner bag41 tends to extend into a non-restricted deployment shape as indicated by the two-dot line in FIGS. 60 and 61, the force of theupper portion42aand thelower portion42bpressing against thefront windshield12 and theinstrument panel13, respectively, increases thereby further increasing the sliding friction between the upper andlower portions42a,42band thebag32 of theair bag31. Therefore, the deploying speed of thebag32 of theair bag31 is further effectively reduced.
• Therefore, in addition to substantially the same advantages as achieved by the second embodiment, the ninth embodiment further achieves the following advantages.[0281]
• Since the[0282]bag42 of theinner bag41 is vertically elongated, the sliding friction between the upper andlower portions42a,42bof thebag42 and thebag32 of theair bag31 is increased so that the deploying speed of thebag32 can be further effectively reduced. Therefore, the ninth embodiment substantially prevents strong contact of theair bag31 with an occupant even if the occupant comes into contact with theair bag31 before it is completely deployed.
• Furthermore, since the[0283]bag42 of theinner bag41 has a simple shape that is vertically elongated, the production of thebag42 becomes easy and, therefore, production efficiency can be improved.
• Tenth Embodiment[0284]
• A tenth embodiment of the invention will be described with reference to FIGS.[0285]62-64.
• In the tenth embodiment, the[0286]bag42 of theinner bag41 has a generally circular sectional shape as shown in FIG. 62. Thebag42 has in transversely opposite side portions thereof a pair of communication holes86 for supplying gas into theair bag31. The communication holes86 are formed at positions that are a distance L1 apart from the opening end of thecase16 when theinner bag41 is deployed. Thebag32 of theair bag31 has in transversely opposite side portions thereof a pair ofoutlet openings87 for letting gas out of theair bag31. Theoutlet openings87 are formed at positions that are a distance L2 apart from the opening end of thecase16 when theair bag31 is deployed. The positional relationship between the communication holes86 and theoutlet openings87 are set such that the distance L1 is greater than the distance L2.
• The[0287]inner bag41, having the above-described construction, is inserted into theair bag31. Theinner bag41 and theair bag31 are fixed and folded in thecase16 as in the second embodiment. In the folded state in thecase16 as shown in FIG. 63, the communication holes86 of theinner bag41 are aligned to theoutlet openings87 of theair bag31, and peripheral edges the holes are sewed to each other with breakable threads (tear seam)88.
• When gas is produced in the[0288]gas generator24 of the passenger seat-sideair bag apparatus11 of this embodiment, gas flows out from thegas ejecting openings20 of thediffuser19, through themouth portion71 of theinner bag41, into thebag42 of theinner bag41 as indicated in FIG. 63, thereby inflating and deploying theinner bag41. After being introduced into theinner bag41, gas flows out through the communication holes86 and theoutlet openings87 as indicated by arrows E in FIGS. 63 and 64. The gas pressure inside theinner bag41 is thereby reduced, and the deploying speed thereof is also reduced.
• The positions of the communication holes[0289]86 of theinner bag41 are different from the positions of theoutlet openings87 of theair bag31 as described above, that is, the distance L1 of the communication holes86 from the opening end of thecase16 is greater than the distance L2 of theoutlet openings87 from the opening end of thecase16. Therefore, theinner bag41 is not completely deployed while the communication holes86 andoutlet openings87 are aligned with each other. More specifically, theinner bag41 can be further inflated by gas pressure therein even after theinner bag41 has reached a maximum deployment limit that is allowed while the communication holes86 andoutlet openings87 are aligned, because there still is a plenty of slack between the communication holes86 and the mountingportion43 as shown in FIG. 64. When the deploying force on theinner bag41 exceeds the strength of the tear seams88 joining the peripheral edges of the communication holes86 andoutlet openings87, the tear seams88 break thereby allowing the holes communication holes86 and outlet holes87 to shift from each other. As a result, gas starts to flow into theair bag31, thereby inflating and deploying theair bag31.
• The shape of side faces of the[0290]inner bag41 is substantially the same as in the ninth embodiment, so that when inflated and deployed, theinner bag41 presses portions of theair bag31 against thefront windshield12 and theinstrument panel13. Therefore, theinner bag41 of the tenth embodiment also produces sliding friction against theair bag31 during the inflating deployment.
• Consequently, in addition to substantially the same advantages as achieved by the ninth embodiment, the tenth embodiment further achieves the following advantages.[0291]
• This embodiment allows gas to flow out of the[0292]inner bag41 during an early period of the deployment of theinner bag41, thereby reducing the gas pressure inside theinner bag41 and the deploying speed of theinner bag41. Even if an occupant comes into contact with theinner bag41 in such an early deployment period, strong contact of theinner bag41 with the occupant can be prevented.
• Furthermore, if an occupant contacts the[0293]air bag31 thereby pressing theinner bag41 in such an early period, gas is allowed to flow out through theoutlet openings87. Therefore, if an occupant comes into contact with theair bag31, the embodiment effectively controls rebound of theinner bag41 that may force the occupant rearward.
• Since the breaking pressure on the tear seams[0294]88 can be adjusted based on the strength thereof or the like, the embodiment makes it possible to adjust the deploying speed of theinner bag41 and theair bag31 without requiring a complicated arrangement.
• It is also possible to adjust the restraining force on an occupant by changing the diameter of the[0295]outlet openings87.
• Eleventh Embodiment[0296]
• An eleventh embodiment of the invention will be described with reference to FIGS.[0297]65-67.
• In the eleventh embodiment, each of communication holes[0298]86 formed in theinner bag41 in substantially the same manner as in the tenth embodiment is provided with aduct89 as shown in FIG. 65.
• The[0299]inner bag41, having the construction described above, is inserted into theair bag31. Theinner bag41 and theair bag31 are fixed and folded in thecase16 in substantially the same manner as in the tenth embodiment. Theducts89 are inserted through theoutlet openings87 of theair bag31 in the folding process, so that theducts89 extends out of theair bag31 in the folded state in thecase16 as shown in FIG. 66. That is, the communication holes86 andoutlet openings87 are aligned to each other as in the tenth embodiment.
• When gas is generated in the[0300]gas generator24 of the passenger seat-sideair bag apparatus11 of this embodiment, gas flows out from thegas ejecting openings20 of thediffuser19, through themouth portion71 of theinner bag41, into thebag42 of theinner bag41, thereby inflating and deploying theinner bag41 substantially in the same manner as in the tenth embodiment.
• After the[0301]inner bag41 reaches a maximum deployment limit that is allowed while the communication holes86 andoutlet openings87 are aligned to each other as shown in FIG. 67, theducts89 are drawn out of the outlet holes87 of theair bag31 as theinner bag41 is further deployed to a final deployment shape. Therefore, as shown in FIG. 65, theducts89 become located inside theair bag31 so that gas is supplied from theinner bag41 into theair bag31 to inflate and deploy theair bag31.
• Therefore, in addition to substantially the same advantages as achieved by the tenth embodiment, the eleventh embodiment further achieves the following advantages.[0302]
• Since there is no need to sew the peripheral edges of the communication holes[0303]86 of theinner bag41 to the peripheral edges of thecorresponding outlet openings87 of theair bag31, the production efficiency of the passenger seat-sideair bag apparatus11 can be improved.
• The timing of the start of gas supply into the[0304]air bag31 can be adjusted by adjusting the length of theducts89. Therefore, the embodiment makes it possible to adjust the deploying speeds of theinner bag41 and theair bag31 while requiring less complicated construction.
• Twelfth Embodiment[0305]
• A twelfth embodiment of the invention will be described with reference to FIGS.[0306]68-69.
• In this embodiment, the[0307]bag42 of theinner bag41 has a generally circular sectional shape as shown in FIGS. 68 and 69. Thebag42 has in transversely opposite side portions thereof a pair of communication holes86 (only one hole is shown in FIGS. 68 and 69). Thebag32 of theair bag31 and thebag42 of theinner bag41 are interconnected by a strap (restriction member)90 having a cord shape. One of thestrap90 is sewed to an occupant-side end portion P1 of thebag42 of theinner bag41 by a thread91 (the occupant-side end portion P1 comes substantially nearest to an occupant in theinner bag41 when theinner bag41 is completely deployed). The other end of thestrap90 is sewed, by athread92, to an occupant-contacting portion P2 of thebag32 of theair bag31 that is located on a horizontal straight line passing through the occupant-side end portion P1 of theinner bag41 when the bags are deployed as shown in FIG. 69. The length of thestrap90 is substantially equal to the distance between the occupant-side end portion P1 and the occupant-contacting portion P2 in the deployed state. Thestrap90 is folded into two and the two sections are sewed together with a breakable thread (tear seam)93 at an appropriate position as clearly shown in FIG. 68, so that the length of thestrap90 is correspondingly reduced.
• The[0308]air bag31 and theinner bag41, having the construction described above, are fixed and folded in thecase16 in substantially the same manner as in the second embodiment.
• When gas is produced from the[0309]inflator18 of the passenger seat-sideair bag apparatus11 of this embodiment, gas is guided into theinner bag41, thereby inflating and deploying theinner bag41. Gas is also supplied from theinner bag41 into theair bag31 to inflate and deploy theair bag31. During an early period of the deployment of theair bag31, the deployment of thebag32 of theair bag31 is restricted by thestrap90 up to a position close to the occupant-side end portion P1 of thebag42 of theinner bag41 as indicated in FIGS. 68 and 69. The deploying speed of theair bag31 toward an occupant side is thereby reduced during an early period of the deployment.
• Subsequently, as the gas pressure inside the[0310]air bag31 increases, thetear seam93 of thestrap90 breaks so that thestrap90 is allowed to extend straight. When theair bag31 is further deployed to a predetermined amount, thestrap90 becomes taut as shown in FIG. 69, thereby restricting the deployment of the occupant-contacting portion P2 of thebag32.
• As the gas pressure inside the[0311]air bag31 further increases, theair bag31 is inflated and deployed to a final shape while being restricted by thestrap90. Thus, the deployment of theair bag31 toward the occupant side is restricted by thestrap90 during early and intermediate periods of the deployment as shown in FIGS. 68 and 69, so that the deploying speed of theair bag31 is effectively reduced. Furthermore, thestrap90 also restricts the direction of the deployment of theair bag31 so that the occupant-contacting portion P2 of thebag32 of theair bag31 moves substantially horizontally during the deployment. Thus, theair bag31 is stably inflated and deployed.
• Therefore, the twelfth embodiment achieves the following advantages.[0312]
• Since the[0313]strap90 restricts the deployment of theair bag31 toward the occupant side, this embodiment reduces the deploying speed of theair bag31 and substantially prevents strong contact of theair bag31 with an occupant even if the occupant comes into contact with theair bag31 before it is completely deployed.
• Since the[0314]strap90 also causes the occupant-contacting portion P2 of thebag32 to move substantially horizontally during the deployment, theair bag31 is stably inflated and deployed. Therefore, even if an occupant comes into contact with theair bag31 before it is completely deployed, it is possible to prevent the rubbing between the occupant and theair bag31.
• The breaking pressure can be adjusted based on the manner of stitch of the tear seam[0315]93 (lock stitch, chain stitch and the like), the strength of the thread, and the like. Furthermore, the positions at which deployment of theair bag31 is restricted can be adjusted based on the length of thestrap90. Therefore, the embodiment makes it possible to adjust the deploying speeds of theinner bag41 and theair bag31 and to adjust the occupant restraining performance without requiring a complicated construction.
• The twelfth embodiment may be modified as follows.[0316]
• Although in the twelfth embodiment, the[0317]strap90 are used to interconnect the sites in theinner bag41 and theair bag31 that come closest to an occupant when the inflating deployment is completed, it is also possible to directly sew those sites together with a tear seam instead of using thestrap90. This modification makes it possible to reduce the deploying speed of theair bag31 while employing a simpler construction. Furthermore, since the deploying speed of theair bag31 is restricted by the restriction member during an early period of the deployment, theair bag31 can be stably inflated and deployed.
• The[0318]strap90 may be reduced in length and may be sewed at both or one of the two ends thereof to theinner bag41 and/or theair bag31 with a tear seam. This modification reduces the deploying speed of theair bag31, and restricts the deploying direction of theair bag31 during early and intermediate periods of the deployment so that the air bag will be stably inflated and deployed.
• Other Embodiments[0319]
• Further possible embodiments according to the invention will be described with reference to FIGS.[0320]70-74. The constructions described below employ modified manners of folding theforward portion32aand therearward portion32bof thebag32 of theair bag31. In these modified constructions, it is also possible to achieve substantially the same advantages as achieved by the foregoing embodiments. The constructions shown in FIGS.70-74 are modifications to the second through twelfth embodiments.
• In the construction shown in FIG. 70, the[0321]inner bag41 is folded into therearward portion32bof theair bag31. Therearward portion32bof thebag32 is folded into generally the shape of a squared roll by rolling it clockwise in a view from the left side of the vehicle. Theforward portion32ais folded into generally the shape of a squared roll by rolling it counterclockwise in a view from the left side of the vehicle.
• In the construction shown in FIG. 71, the[0322]inner bag41 is folded into theforward portion32aof thebag32 of theair bag31. Theforward portion32aand therearward portion32bof thebag32 are folded separately into accordion folds.
• In the construction shown in FIG. 72, the[0323]inner bag41 is folded into therearward portion32bof thebag32 of theair bag31, conversely to the construction shown in FIG. 71. Theforward portion32aand therearward portion32bof thebag32 are folded separately into accordion folds.
• In the construction shown in FIG. 73, the[0324]inner bag41 is folded into theforward portion32aof thebag32 of theair bag31. Theforward portion32aof thebag32 is folded into generally the shape of a squared roll by rolling it counterclockwise in a view from the left side of the vehicle. Therearward portion32bis folded into accordion folds.
• In the construction shown in FIG. 74, the[0325]inner bag41 is folded into therearward portion32bof thebag32 of theair bag31, conversely to the construction shown in FIG. 73. Therearward portion32bof thebag32 is folded into generally the shape of a squared roll by rolling it clockwise in a view from the left side of the vehicle. Theforward portion32ais folded into accordion folds.
• The first through twelfth embodiments and the other embodiments may be modified as follows.[0326]
• The shape of the[0327]case16, the position of the inflator18 in thecase16, and the manner of folding theair bag31 and theinner bag41 into thecase16 in the second through twelfth embodiments may be changed to substantially the same as those in the first embodiment.
• The shape of the[0328]case16, the position of the inflator18 in thecase16, and the manner of folding theair bag31 and theinner bag41 into thecase16 in the first embodiment may be changed to substantially the same as those in the second through twelfth embodiments.
• The auxiliary[0329]inner bag46 disposed on thebag42 of theinner bag41 in the first embodiment may also be provided on thebag42 in the second through twelfth embodiments. This modification ensures that therearward portion32bof thebag32 of theair bag31 will be sandwiched between the auxiliaryinner bag46 and theinstrument panel13. Therefore, it becomes possible to more reliably prevent therearward portion32bof thebag32 from being deployed toward the occupant side during an early period of the deployment.
• The constructions and portions in the foregoing embodiments may be suitably combined. For example, the[0330]strap90 in the twelfth embodiment may be provided between theinner bag41 and theair bag31 in the construction according to any one of the first through eleventh embodiments or the other embodiments.
• While the present invention has been described with reference to what are presently considered to be preferred embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments or constructions. To the contrary, the invention is intended to cover various modifications and equivalent arrangements.[0331]

Claims (30)

What is claimed is:

1. An air bag apparatus for a passenger seat disposed in a passenger seat-side instrument panel, comprising:

an air bag folded and disposed in a case having at one side thereof an opening; and

an inner bag disposed in the air bag, the air bag and inner bag being arranged in a manner so that the inner bag is inflated prior to inflation of the air bag, the inner bag being arranged to press a portion of the air bag against at least one of a front glass pane and an instrument panel when inflated.

2. An air bag apparatus for a passenger seat according to

claim 1

, wherein the inner bag has a supply hole for supplying gas to the air bag.

3. An air bag apparatus for a passenger seat according to

claim 1

, wherein the inner bag is designed to press a portion of the air bag against each of the front glass pane and the instrument panel when inflated.

4. An air bag apparatus for a passenger seat according to

claim 3

, wherein the inner bag has an upper inflating portion and a lower inflating portion, and the upper inflating portion is formed so as to inflate to a greater size than the lower inflating portion.

5. An air bag apparatus for a passenger seat according to

claim 3

, further comprising a restriction member disposed in the inner bag, the restriction member restricting inflation of a central portion of the inner bag to a predetermined amount and defining, at least partially, two inflating portions in the inner bag.

6. An air bag apparatus for a passenger seat according to

claim 5

, wherein the inner bag is constituted at least in part by an upper face cloth sewed to a lower face cloth, the cloths being constructed and arranged such that the upper cloth is inflated and deployed in an upward direction relative to the vehicle and the lower cloth is inflated and deployed in a downward direction relative the vehicle.

7. An air bag apparatus for a passenger seat according to

claim 6

, wherein the restriction member extends from an end of at least one of the upper face cloth and the lower face cloth.

8. An air bag apparatus for a passenger seat according to

claim 6

, wherein the restriction member is disposed in the inner bag at a lower position therein so that an upward deploying portion of the inner bag is inflated and deployed to a greater size than a downward deploying portion of the inner bag.

9. An air bag apparatus for a passenger seat according to

claim 3

, wherein the inner bag is formed by two base cloths so that when the inner bag is inflated and deployed, the base cloths face each other in transverse directions relative to the vehicle and the inner bag is inflated and deployed in upward and downward directions relative to the vehicle.

10. An air bag apparatus for a passenger seat according to

claim 3

, constructed and arranged so that when inflated, the inner bag assumes a generally gourd shape in a side view.

11. An air bag apparatus for a passenger seat according to

claim 3

, constructed and arranged so that when inflated, the inner bag contacts the front glass pane and the instrument panel and curves into a generally crescent shape in a side view.

12. An air bag apparatus for a passenger seat according to

claim 1

, wherein the inner bag has an extension portion that extends in a rearward direction relative to the vehicle, the extension portion pressing a portion of the air bag against the instrument panel.

13. An air bag apparatus for a passenger seat according to

claim 1

, wherein the inner bag has a forward ejection hole for ejecting gas in a forward direction relative to the vehicle.

14. An air bag apparatus for a passenger seat according to

claim 1

, wherein before being disposed in the case, the air bag is folded by folding portions of the air bag that face in forward and rearward directions relative to the vehicle and then folding portions of the air bag that face in transverse directions relative to the vehicle.

15. An air bag apparatus for a passenger seat according to

claim 14

, wherein the inner bag is folded by folding opposite end portions thereof that face in the transverse directions relative to the vehicle while avoiding folding a central portion of the air bag relative to the case, in the transverse directions.

16. An air bag apparatus for a passenger seat according to

claim 1

, further comprising an inflator having a cylindrical shape and disposed so that an axis thereof extends substantially in a fore-to-aft direction relative to the vehicle.

17. An air bag apparatus for a passenger seat according to

claim 16

, wherein a portion of the air bag is disposed between an inner wall face of the case and right and left sides of the inflator.

18. An air bag apparatus for a passenger seat according to

claim 1

,

wherein the air bag has a fixing portion at which the air bag is fixed to the case and a mouth portion that guides gas into the air bag, and

wherein the mouth portion is disposed in a central portion of the case, and an upward deploying portion of the air bag and a downward deploying portion of the air bag are folded and disposed in a space between the mouth portion and one of opposite inner surfaces of the case that face the mouth portion and a space between the mouth portion and the other one of the opposite inner surfaces of the case, respectively.

19. An air bag apparatus for a passenger seat according to

claim 1

, further comprising an air bag cover disposed at the opening of the case, the air bag cover being openable in transverse directions relative to the vehicle in a manner of a double-hinged door.

20. An air bag apparatus for a passenger seat according to

claim 1

,

wherein the air bag has an outlet hole for letting out gas, and

wherein the inner bag has a supply hole for supplying gas to the air bag, and wherein the air bag and the inner bag are disposed in the case in such a manner that the outlet hole of the air bag and the supply hole of the inner bag correspond to each other and, during inflation of the inner bag and the air bag, the supply hole and the outlet hole become separate from each other.

21. An air bag apparatus for a passenger seat according to

claim 20

, wherein the outlet hole of the air bag and the supply hole of the inner bag are sewed together at peripheral portions thereof so as to correspond to each other, using a thread that breaks when the air bag and the inner bag are inflated.

22. An air bag apparatus for a passenger seat according to

claim 1

, wherein a site in the inner bag and a site in the air bag that come closest to an occupant side at the time of completion of inflation and deployment of the inner bag and the air bag are interconnected so that the sites remain interconnected during an early period of the inflation of the inner bag and the air bag, and so that the sites are disconnected from each other as the inner bag and the air bag are further inflated.

23. An air bag apparatus for a passenger seat disposed in a passenger seat-side instrument panel, comprising:

an air bag folded and disposed in a case having at one side thereof an opening, the air bag having an outlet hole for letting out gas; and

an inner bag disposed in the air bag so that the inner bag is inflated prior to inflation of the air bag, the inner bag having a supply hole for supplying gas to the air bag,

the air bag and the inner bag being disposed in the case in such a manner that the outlet hole of the air bag and the supply hole of the inner bag correspond to each other and, during inflation of the inner bag and the air bag, the supply hole and the outlet hole become separate from each other.

24. An air bag apparatus for a passenger seat according to

claim 23

, wherein the outlet hole of the air bag and the supply hole of the inner bag are sewed together at peripheral portions thereof so as to correspond to each other, using a thread that breaks when the air bag and the inner bag are inflated.

25. An air bag apparatus for a passenger seat according to

claim 23

, wherein the inner bag is provided with a duct extending therefrom corresponding to the supply hole, and wherein the inner bag and the air bag are folded and disposed in the case in such a manner that the duct protrudes out from the outlet hole of the air bag.

26. An air bag apparatus for a passenger seat according to

claim 23

, wherein a site in the inner bag and a site in the air bag that come closest to an occupant side at the time of completion of inflation and deployment of the inner bag and the air bag are interconnected so that the sites remain interconnected during an early period of the inflation of the inner bag and the air bag, and so that the sites are disconnected from each other as the inner bag and the air bag are further inflated.

27. An air bag apparatus for a passenger seat disposed in a passenger seat-side instrument panel, comprising:

an air bag folded and disposed in a case having at one side thereof an opening; and

an inner bag disposed in the air bag so that the inner bag is inflated prior to inflation of the air bag,

a site in the inner bag and a site in the air bag that come closest to an occupant side at the time of completion of inflation and deployment of the inner bag and the air bag being interconnected so that the sites remain interconnected during an early period of the inflation of the inner bag and the air bag, and so that the sites are disconnected from each other as the inner bag and the air bag are further inflated.

28. An air bag apparatus for a passenger seat according to

claim 27

, wherein the inner bag has a supply hole for supplying gas to the air bag.

29. An air bag apparatus for a passenger seat according to

claim 27

, wherein a site in the inner bag and a site in the air bag that come closest to an occupant side at the time of completion of inflation and deployment of the inner bag and the air bag are interconnected by a restriction member that is folded and sewed with a breakable thread so that the folded sections of the restriction member are joined together.

30. An air bag apparatus for a passenger seat according to

claim 27

, wherein the interconnected sites in the inner bag and the air bag are directly sewed together using a thread that breaks when the inner bag and the air bag are inflated.

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