US3902628A - Plastic container hinge and latch - Google Patents

Abstract

Blow-molded plastic container body and cover parts are hinged together by a cover joint formation integrally formed thereon and received in a body trough formation having sockets at the opposite ends thereof receiving hinge pins integrally formed at the opposite ends of the cover joint formation. A tapered latch tongue formed integral with the cover is received in snap-fitted engagement with a tapered latch receiving formation on the body for releasably latching the cover and body parts in closed position.

Description

United States Patent [191 Schurman 1 1 Sept. 2, 1975 PLASTIC CONTAINER HINGE AND LATCH [75] Inventor: Peter T. Schurman, Woodbridge,

Conn,

[73] Assignee: The Plastic Forming Company, Inc.,

Woodbridge, Conn.

22 Filed: Sept. 13, 1972 21 App1.No.: 288,707

[52] US. Cl 220/306; 220/343 [51] Int.Cl B65d 43/10;B65d 43/16 [58] Field of Search 220/31 S, 31 R, 60 R, 306,

220/307, 343; 24/208 A, 213 R, 224 PS, 224

[56] References Cited UNITED STATES PATENTS 2,295,494 9/1942 Valentine 220/31 S 2,702,651 2/1955 Graham 220/31 S 2,842,178 7/1958 Solomon 3,339,781 9/1967 Schurman et a1. 220/60 R Schurrnan 220/82 R 3,612,233 10/1971 Nagpal 206/52 F 3,645,758 2/1972 MacManus 220/306 3,651,992 3/1972 Hazard 1 220/31 S D145,008 6/1946 Crane 220/31 S Primary Examiner-l-lerbert 1?. Ross Assistant ExaminerAl1an N. Shoap Attorney, Agent, or FirmChristel & Bean [5 7] ABSTRACT Blow-molded plastic container body and cover parts are hinged together by a cover joint formation integrally formed thereon and received in a body trough formation having sockets at the opposite ends thereof receiving hinge pins integrally formed at the opposite ends of the cover joint formation. A tapered latch tongue formed integral with the cover is received in snap-fitted engagement with a tapered latch receiving formation on the body for releasably latching the cover and body parts in closed position.

6 Claims, 14 Drawing Figures PATENTEB 21975 3,902,628

ILL] PLASTIC CONTAINER HINGE AND LATCH BACKGROUND OF THE INVENTION This invention relates generally to the plastic container art, and more particularly to a new and improved hinge joint and latch for joining blow molded cover and body parts and latching them together in closed position.

The forming of separate container bodies and covers offers certain advantages in production and also enables merchandise to be shrink-wrapped in the body prior to assembly of the cover. Moreover. the body and cover can be formed of different materials and colors, as desired. Blow molding such container parts to form double wall constructions also is desirable from various parts of view. For example, the double wall construction provides a cushioned arrangement wherein the inner wall can be shaped to form pockets conforming generally to the shape of the articles to be received therein for packaging. However, a problem arises in hinging such blow molded parts together, particularly in heavy duty applications. While such parts can be separately pinned it is advantageous, where possible, to provide a selfcontained hinge construction which can be quickly and easily assembled by either the moldcr or the packager without need for complex tooling.

Problems also are encountered in providing a suitable latch for such hinged container parts. Where the latch is formed separate from the container parts, an additional assembly step is involved, adding to production costs. While this can be avoided by molding the latch integral with one of the container parts, problems remain in providing a latch of sufficient strength and durability without imposing undesirable design limitations.

SUMMARY OF THE INVENTION Accordingly, an object of this invention is to provide an improved hinge joint formed integral with blow molded container parts which facilitates assembly without complex tooling, contemplates a wide range of container styling variations, provides a substantially continuous or closed hinge construction to enhance container appearance, and provides a positive step for the container cover in an open position.

Another object of this invention is to provide an integral latch construction for blow molded container parts which has excellent latching action and securing characteristics, is only moderately stressed during movement between the latched and released positions, and which is esthetically extremely pleasing.

In one aspect thereof, a plastic container of the present invention is characterized by the provision of a blow molded cover having formed as an integral part thereof a pair of hinge pins and a joint formation extending therebetween, and a body having spaced apart hinge pin receiving means and a trough formation extending therebetween receiving the cover joint formation in assembled relation. In another aspect thereof, a plastic container of this invention is characterized by the provision of a latch tongue of tapered side wall form integral with one container part and having snap in engagement with a recess of tapered side wall form on the other container part for securing the container in closed position.

The foregoing and other objects, advantages, and characterizing features of the present invention will become clearly apparent from the ensuing detailed description of an illustrative embodiment thereof, taken together with the accompanying drawings wherein like reference numerals denote like parts throughout the various views.

BRIEF DESCRIPTION OF THE DRAWING FIGURES FIG. 1 is a top plan view of an illustrative container embodying the present invention, in closed position;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a side elevational view thereof;

FIG. 5 is a vertical sectional view, on an enlarged scale, taken about on line 5-5 of FIG. 1, showing the container in a fully opened position;

FIG. 6 is a fragmentary front elevational view, on an enlarged scale, showing container in an open position with the latch disengaged;

FIG. 7 is a view similar to FIG. 6 but showing the container in closedposition with the latch fully engaged and locking the container parts closed;

FIG. 8 is a fragmentary top plan view of the container body, looking in the direction of arrows 8-8 in FIG.

FIG. 9 is a fragmentary horizontal sectional view, taken about on line 9-9 of FIG. 6;

FIG. 10 is a fragmentary horizontal sectional view, taken about on line 10-10 of FIG. 7;

FIG. 11 is a fragmentary top plan view, partially in section, on an enlarged scale, showing the hinge joint formation of this invention;

FIG. 12 is a fragmentary top plan view, on an enlarged scale, of the container body, showing the hinge trough formation therein;

FIG. 13 is a transverse, cross sectional view, on an enlarged scale, taken about on line 13-13 of FIG. 1 parts being broken away in FIGS. l1, l2 and 13 for convenience in illustration; and

FIG. 14 is a fragmentary vertical sectional view, taken about on line 14l4 of FIG. 11.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENT The illustrative container depicted in the accompanying drawings comprises a base or body, generally designated 20, and a lid or cover therefor, generally designated 21.Body 20 is formed of a suitable thermoplastic material blow-molded into the desired shape and having a hollow, double wall construction formed by an outer shell 22 (FIGS. 5 and 13) comprisingopposite side walls 23, afront wall 25, arear wall 26 and abottom wall 27, and aninner shell 28 formed to provide a generally recessed compartment (FIGS. 5 and 13) withinouter shell 22 in spaced relation thereto except adjacent the edge portions thereof where it is connected to the upper edge of the outer shell. If desired,inner shell 28 can extend across the upper end ofouter shell 22 and can be compartmented or provided with pockets for receiving variously shaped articles therein. Also, afterbody 20 is removed from the mold, one or more portions ofinner shell 28 can be cut-away, as desired, to provide access to the interior ofbody 20 between the inner and outer shells for storage or any other purpose.

Cover 21 also is formed of thermoplastic material blow-molded into a hollow. double wall construction defined by an outer shell havingopposite side walls 30, arear wall 31, afront wall 32 and atop wall 33, and an inner shell extending across the outer shell in spaced relation thereto except adjacent the edge portions thereof where it is connected thereto. The cover inner shell has atop wall 35 formed to provide arecessed compartment 36, front andrear walls 37, 38 andopposite side walls 40. A generallyhorizontal ledge 41 extends outwardly from the outer ends offront wall 37 andside walls 40 and connects the cover inner shell to the outer shell thereof.

The outer shell ofbody 20 is formed to provide an outwardlyoffset band 42, extending horizontally aroundbody 10 adjacent the upper end thereof and the juncture of theouter shell 22 withinner shell 28. Theinner shell 28 is formed, adjacent its connection with theouter shell band 42, with a raised shoulder 43 (FIG. extending inwardly from the upper edge ofband 42 and terminating at its lower end in a generallyhorizontal ledge 45 which extends about the upper inner edge of body and against which cover ledge 41 abuts whencover 21 is closed. Thus, the parting line betweencover 21 and body at theabutting ledges 41 and 45 is disposed below and concealed by the upper edge ofband 42, thereby creating an attractive container appearance.

An important feature of this invention resides in the provision of a closed hinge joint all parts of which are formed with and as an integral part of either the body or the cover. To this end, atrough formation 46 of a generally U-shaped transverse configuration is provided along the upper rear edge ofbody 20 betweenledge 45 and the upper end ofband 42. As shown in FIGS. 5 and 13,trough formation 46 is a channel defined by an inclinedouter wall 47 joined to the upper edge ofband 42, a steppedinner wall 48 extending downwardly from the outer edge ofledge 45, and abottom wall 50 connecting the outer andinner walls 47 and 48. Steppedinner wall 48 as shown in FIG. 13 consists of avertical portion 48a, aninclined portion 48b and a short ledge or step portion 480.Elements 48b, 50 and 47 form a trapezoidal channel intrough formation 46.

A pair of hollow, bulbous formations orsections 51 are formed integral with the upper, rear edge ofbody 20 at the opposite ends oftrough 46 and are provided withopenings 53 through the inner transverse walls thereof which are upstanding at the opposite ends oftrough 46 to define inwardly openingsockets 52 therein (FIG. 11) aligned withtrough 46 for receiving cover hinge pins, hereinafter described. The inlet openings ofsockets 52 are defined byannular walls 55 which serve as hinge pin bearings in the assembled relation.

Container cover 21 is provided with an elongatedjoint formation 56 formed integral withcover 21 along the lower rear edge thereof. As shown in FIGS. 5 and 13,joint formation 56 is hollow and is formed in part by the outer portion of the inner shellrear wall 38 and an arcuatclycurved wall portion 57 connected to outer shellrear wall 31 by a straight wall portion 58. A pair of coaxially aligned hollow hinge pins 60 also are formedintegral withjoint formation 56 and project axially outwardly from the opposite ends thereof so as to be oppositely directed.Wall portion 57 is curved on a radius about the axis of hinge pins 60, such radius being larger than the radius of hinge pins 60.

Whencover 21 andbody 20 are assembled, the coverjoint formation 56 is receivedintrough formation 46 and hinge pins 60 project throughopenings 53 intosockets 52 thewalls 55 of which serve as hinge pin bearings whencover 21 is swung between open and closed positions. In assemblingcover 21 tocontainer body 20, the inherent resiliency of the plastic material of whichbody 20 and cover 21 are formed permits both to be flexed sufficiently to allow the passage of hinge pins past the opposed faces ofsocket formations 57 and intosockets 52 for pivotal engagement therein. Thus, cover 21 is easily attached tobody 20 by a simple mechanical fixture without the use of complex tooling and without need for hinge parts separate from the molded container parts. Whencover 21 andbody 20 are assembled,joint formation 56 extends intotrough 46 for the full length thereof betweensockets 52. As shown in FIG. 13 the configuration of the arcuatecurved wall portion 57 of thejoint formation 56 is such that when the cover is closed,portion 57 is located in the channel defined bywalls 48b and 47 andbottom wall 50. When the cover is raised as shown in FIG. 5,

arcuatecurved wall portion 57 contactsvertical wall portion 48a, inclined portion 480 andbottom wall 50. Thus the configuration ofjoint formation 56 is such that a portion of the full length thereof is disposed within the channel oftrough formation 46, below the upper plane ofbody 20, at all positions ofcover 21. This, together with the concealment of hinge pins 60 withinsockets 52 effects a substantially continuous hinge joint which, as viewed from the inside or open position of the container, is closed at all times during opening and closing ofcover 21, as clearly apparent from FIGS. 5 and 13. This closed hinge construction eliminates the usual gap or open spaces commonly found between the bodies and covers of conventional containers in an open position and greatly enhances the appearance of the container. Furthermore, this closed hinge construction permits numerous container styling variations to be made without detracting from the overall appearance of the container.

Another advantage residing in the closed hinge con struction of this invention is in the provision of a positive stop forcover 21 at a predetermined open position. As shown in FIG. 5, the inwardly offset orientation of outer shellrear wall 31 relative toarcuate wall portion 57, together with the upper recessed edge 61 ofband 42 along the rear end ofbody 20, enablescover 21 to be swung past for example to about for more convenient access intobody 20. However, at the full open position,rear wall 31 engages the recessed edge 61 ofband 42, limiting further opening ofcover 21. The flatrear wall 38 of the cover inner shell provides clearance assuring proper closing ofcover 21 without interference with any other portion ofbody 20. Hinge pins 60 are of relatively large diameter, several times the wall thickness of the container, for greater bearing area and strength.

Another significant feature of the present invention resides in the latching arrangement provided thereby. As shown in FIGS. 6-10 and 13, a latch member, generally designated 62, is formed integral with the lower edge of coverfront wall 32 for reception into an associated latch receiving means. generally designated 63, provided along the upper portion ofbody front wall 25 for releasably lockingcover 21 tobody 20 in closed position. It should be appreciated that in larger, heavier container constructions, two or more latches with corresponding latch receiving means can be provided. desired.

Latch member 62 comprises atongue 65 ofa generally trapezoidal outline having tapered side edges eX- tending towardcover 21 in a converging relation and joined to cover 21 by a connectingflange portion 66 formed integral with the upper end oftongue 65 and with the lower edge of coverfront wall 32.Flange 66 projects forwardly of coverfront wall 32 and serves as a pivotal, hinge connection for swingingtongue 65 through relatively small arcuate movements.Tongue 65 is provided with a pair ofinturned side walls 67 extending substantially the length of the tapered side edges thereof and of progressively increasing width from the upper end oftongue 65 to thc bottom end thereof. Also. the wall thickness oftongue 65 progressively increases from the top to the bottom thereof.Cover 21 and body are blow molded, as by trapping a portion of a parison of thermoplastic material between a pair of mold sections and expanding the same into conformance with the mold faces, in a manner well known in the art.Tongue 65 is formed withcover 21 by compressing together opposite wall portions of the trapped material during the blow molding operation to form a tongue wall which is thicker, in part at least, than the individual wall thickness of the trapped material or the walls of the finished container parts. Eachside wall 67 is formed with a laterally projecting bead orprotuberance 68 for a purpose to the explained.

The upper central portion of container body front wall is formed with a slight recess, as defined by a generally vertical wall surface 70 (FIG. 13) terminating at its upper end in an outwardly directed ledge 71 having a central recess 72 therein (FIG. 8). Also, the outwardly offsetband 42 is discontinuous adjacent the central portion ofbody front wall 25, forming arecess 73 defined by a pair of axially spaced, taperedwalls 75 extending inwardly to the plane ofvertical wall surface 70 to form the latch receiving means 63 of this invention.Walls 75 are inclined towardcover 21 in a converging relation corresponding to the tapered side edge form oftongue 65 to accommodate the latter in the latched position. A pair ofshoulders 76 are formed at the juncture ofband 42 withwalls 75 and haveouter portions 77 projecting forwardly out of the plane ofband 42 andinner edge portions 78 projecting inwardly fromwalls 75 intorecess 73 to provide undercut recesses in the sidewalls defining recess 73. Theseundercut shoulders 76 are blow molded with and as an integral part ofcontainer body 20 and complete the latch receiving means 63 of this invention.

Whencover 21 is pivoted into a closed position with thecover ledge 41 confined withinband 42 and abuttingcontainer body ledge 45,tongue 65 lies in its normal plane of repose with the major portion thereof disposed outwardly ofrecess 73 and with lockingbeads 68 positioned adjacent theouter portions 77 ofshoulders 76, as shown in FIG. 13. In order to latchcover 21 in this closed position,tongue 65 is depressed towardbody 20, and pivoted inwardly intorecess 73 about a horizontal axis defined at the juncture of connectingflange 66 and the lowerend of coverfront wall 32. The inherent resiliency of the plastic material forming the latch permits the passage ofbeads 68 past the inwardly directedportions 78 ofshoulders 76 and into the undercutrecess 73 behindshoulders 76 with a snap-fit engagement (FIG. 10), theinner portions 78 ofshoulders 76 resiliently yielding and deforming to permit snap passage ofbeads 68 through the restricted inlet defined between shoulderinner portions 78. Once assembled, the engagement of beads ,68 behindshoulders 76 precludes accidental removal of latching tongue fromrecess 63. Any force tending to movecover 21 upwardly, away fromcontainer body 20, is resisted by the wedging eoaction between thetapered walls 75 ofband 42 and theinclined side walls 67 oftongue 65, and tends to more securely locktongue 65 in place.

Whenlatch member 62 is in the latched position withtongue 65 withinrecess 73 andbeads 68 engaged behindshoulders 76, latch member 62lies closely adjacent its natural plane of repose whereby it is not under any significant stress. Ledge 71 offers a measure of support to latchportion 66 in latched position. Latchingbeads 68 are snappedpast shoulders 76 by depressing or lifting tongue 65'to latch and release thecontainer cover 21. In the latched position, the lower edge oftongue 65 is sufficiently spaced from thevertical wall surface 70 to permit insertion of the users thumb or finger to readily lift or releasetongue 65 fromrecess 73. As shown in FIG. 13,tongue 65 extends at about a right angle to the connectinghinge 66 which is molded at a slight, e.g. 20 upward angle to coverledge 41, whereby in its natural condition ofrepose tongue 65 just clears the associatedbody portions 76 ascover 21 is moved into closed position.Tongue 65 therefore is flexed through a relatively small or angle during latching and unlatching movement thereof so as to produce only a minimum of stress and strain thereon. Moreover, this short pivotal movement facilitates dimensional accuracy in positioningtongue 65 in the desired holding position. As a result,latch member 62 is assured a relatively long useful life, assuming normal usage thereof, and requires only to be formed of a suitable tear resistant material, such as polyethylene or polypropylene, for example, having a long flex life.

The container parts, including the hinge joint and the latch, can be made of any suitable thermoplastic material, such as high density polyethylene and polypropylene, which are given by way of example only. It should be understood that the hinge joint and latch of this invention are not dependent upon or limited to use with each other, nor are they intended to be limited in use with the specific container described and illustrated, but have utility, whether taken together or separately, in a wide variety of applications where it is desired to hingedly mount one part to another and/or releasably latch them together.

Also. it will be appreciated that the foregoing detailed description is given by way of illustration only, and thattrough 46, for example, can be of curved rather than straight wall form.

From the foregoing, it is apparent that the objects of the present invention have been fully accomplished. There is provided an improved closed hinge construction formed integral with the container parts for simplicity and enhancing the appearance of the container while permitting a wide range of container styling vari ations. A latch member is formed integral with the cover and offers improved latching action while permitting a wide range of styling variation.

I claim:

1. A container comprising a body of thermoplastic material, a cover of thermoplastic material hinged to said body for movement between open and closed positions relative thereto, a latch member formed integral with said cover, said cover being of double wall construction and said latch member comprising a tongue of tapered side wall form joined to a wall of said cover by a connecting portion, said body being of double wall construction formed to provide a tongue receiving recess in a wall thereof, said recess being of tapered side wall form corresponding to the tapered side wall form of said tongue, the side walls of said recess being undercut and the side walls of said tongue having snap-fitting engagement with said undercut recess side walls for releasably confining said tongue within said recess, said tongue and said recess being tapered toward said cover and coacting when engaged to releasably latch said cover in closed position.

2. A container as set forth in claim 1, wherein said latch member is of single wall form whose position of repose is closely adjacent its position of latching engagement within said recess.

3. A container as set forth in claim 1, said body being formed to provide a pair of opposed shoulder portions along the outer edges of said recess side walls and projecting into said recess to form said undercut therebehind.

4. A container as set forth in claim 3, said tongue side walls having laterally projecting beads for snap-fitting past said shoulder portions into said undercut.

5. A container as set forth in claim 1 wherein said connecting portion is formed integral with the upper end of said tongue and with said cover wall and positions said tongue just outside of said recess in its natural condition of repose, said connecting portion providing a hinge about which said tongue is pivoted through relatively small angular movements between latching and unlatching positions.

6. A container as set forth in claim 1 wherein said tongue has a thickness greater than the wall thickness of said cover portion and of progressively increasing thickness from said connecting portion to the free end

Claims (6)

1. A container comprising a body of thermoplastic material, a cover of thermoplastic material hinged to said body for movement between open and closed positions relative thereto, a latch member formed integral with said cover, said cover being of double wall construction and said latch member comprising a tongue of tapered side wall form joined to a wall of said cover by a connecting portion, said body being of double wall construction formed to provide a tongue receiving recess in a wall thereof, said recess being of tapered side wall form corresponding to the tapered side wall form of said tongue, the side walls of said recess being undercut and the side walls of said tongue having snap-fitting engagement with said undercut recess side walls for releasably confining said tongue within said recess, said tongue and said recess being tapered toward said cover and coacting when engaged to releasably latch said cover in closed position.

2. A container as set forth in claim 1, wherein said latch member is of single wall form whose position of repose is closely adjacent its position of latching engagement within said recess.

3. A container as set forth in claim 1, said body being formed to provide a pair of opposed shoulder portions along the outer edges of said recess side walls and projecting into said recess to form said undercut therebehind.

4. A container as set forth in claim 3, said tongue side walls having laterally projecting beads for snap-fitting past said shoulder portions into said undercut.

5. A container as set forth in claim 1 wherein said connecting portion is formed integral with the upper end of said tongue and with said cover wall and positions said tongue just outside of said recess in its natural condition of repose, said connecting portion providing a hinge about which said tongue is pivoted through relatively small angular movements between latching and unlatching positions.

6. A container as set forth in claim 1 wherein said tongue has a thickness greater than the wall thickness of said cover portion and of progressively increasing thickness from said connecting portion to the free end thereof.

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