CROSS REFERENCE TO RELATED APPLICATIONS This application is a continuation-in-part of application Ser. No. 10/896,572, filed Jul. 22, 2004, which claims the benefit of provisional patent application Ser. No. 60/489,041, filed Jul. 22, 2003, both of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION The invention relates generally to furniture and more specifically to a chair cushion that provides improved pressure distribution and reduced pressure at high pressure points.
Sitting on a chair for long periods of time can result in discomfort in the buttocks, particularly at high pressure points such as the ischia and bony prominences. It also can cause discomfort in the back, for example, the spine, shoulders and shoulder blades. Although a number of chairs are available having padding or the like, it would be beneficial to provide a chair that includes a seat cushion that provides improved pressure distribution and reduced pressure at high pressure points, and even more beneficial if the user can easily and conveniently adjust the pressure distribution and reduction aspects of the cushion. Furthermore, it would be advantageous to provide a chair, particularly a lounge chair or recliner, that provides improved pressure distribution under the back, arms and legs.
SUMMARY OF THE INVENTION One aspect of the invention provides a chair having seat including a contoured, padded base with an inflatable air cell pad positioned securely within the base and encased within a cover. The air cell pad is optimally located in the base so as to be positioned under the user's buttocks, particularly under the high-pressure areas of the buttocks of a normally positioned user. The inflatable air cell pad is operatively connected to a pump device located outside the cover for access by the user of the chair. The user can sit on the cushion and then inflate or deflate the air cell pad for optimal support and comfort. The pump can be of any acceptable design. In one aspect of the invention the pump comprises a bulb and valve combination.
In another aspect of the invention, the seat cushion is employed in an easy chair, lounge chair or recliner. The inflatable air cell pad cushion is operatively connected to a pump such as the one described. Alternatively, in another aspect of the invention, the inflatable air cell pad can be connected to an automatic pump, such as a small electric pump. The pump is operatively connected to a controller. The seated user can actuate the controller to set the inflation level of a desired level for optimal support and comfort.
In yet another aspect of the invention, the base with an air cell pad is positioned in the back rest of the chair and can be operatively connected to a manual or automatic pump and controller.
In another aspect of the invention the base comprises a substantially rigid frame with the air cell pad positioned within the frame. The base and air cell pad are enclosed within the chair seat or backrest or both.
In another aspect of the invention, the chair has pressure-distributing pads under high-pressure areas, including the seat, the backrest, head and/or neck rest, the armrests and a leg rest.
Moreover, in another aspect of the invention, the pressure-distributing pads comprise a pad selected from a group of pressure-distributing pads consisting of air cell pads, inflatable pillows or gel-type pads.
BRIEF DESCRIPTION OF THE DRAWINGS The patent or patent application contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawings will be provided by the Office upon request and payment of the necessary fee.
FIG. 1 is a perspective view of a representative embodiment of an office chair including a seat cushion of the present invention with the seat cover partial cut away to expose the air cell insert;
FIG. 2 is a perspective view of the seat cushion of the present invention, sans cover;
FIG. 3 is a cross sectional view of the cushion of the present invention taken along line3-3 ofFIG. 2;
FIG. 4 is a side elevational view of the cushion of the present invention;
FIG. 5 is a perspective view of the air cell pad;
FIG. 6 is a cross section view of the cushion of the present invention, similar toFIG. 3, wherein the air cell pad is inserted in a cavity formed in the top of the resilient base;
FIG. 7 is a front plan view of a representative embodiment of recliner chair including a back rest cushion and a seat cushion of the present invention with the covering partial cut away to expose the air cell inserts;
FIG. 8 is a side elevational view of a representative embodiment of recliner chair in a reclining position;
FIG. 9 is a perspective view of a representative embodiment of a side chair including a back rest cushion and a seat cushion of the present invention with the covering partial cut away to expose the air cell inserts;
FIG. 10 is a side elevational view of another representative embodiment of a recliner chair in a reclining position;
FIG. 11 is a pressure map of a prior art office chair seat cushion showing areas of distribution of 50 mm Hg pressure;
FIG. 12 is a pressure map of a seat cushion of the present invention showing areas of distribution of 50 mm Hg pressure;
FIG. 13 is a pressure map of a prior art office chair seat cushion showing areas of distribution of 40 mm Hg pressure;
FIG. 14 is a pressure map of a seat cushion of the present invention showing areas of distribution of 40 mm Hg pressure;
FIG. 15 is a pressure map of a prior art office chair seat cushion showing areas of distribution of 30 mm Hg pressure; and
FIG. 16 is a pressure map of a seat cushion of the present invention showing areas of distribution of 30 mm Hg pressure.
DETAILED DESCRIPTION OF ONE EMBODIMENT OF THE INVENTION A chair, employing a seat cushion of the present invention is indicated generally inFIG. 1 byreference numeral20.Chair20, in the embodiment ofFIG. 1, is configured like a conventional office chair. Howeverchair20 can be of any acceptable configuration and, at a minimum includes aseat cushion21.Chair20 also includes abackrest23.Chair20, as shown, includes afloor engaging base25 havingcasters27 and an upwardly extendingpedestal29 connected to a pan30 (FIG. 3) on which the seat cushion is mounted.Pedestal29 generally is connected topan30 by a swivel connection (not shown).
Backrest23 includes a structural frame (not shown) and is attached to the seat pan by anappropriate brace31 or the like. In most embodiments,base25,casters27,pedestal29,pan30,brace31 and the backrest frame are constructed of metal. Hence, the backrest is padded for comfort, as is the seat cushion, as will be explained below, and both are enclosed by anacceptable cover33.Cover33 usually is a durable, aesthetically pleasing fabric. In the present invention, certain physical qualities are preferred, particularly the cover ofseat cushion21.
It will be appreciated thatchair20 as shown is a basic configuration for simplicity of description, and the acceptable configurations of a chair employing the seat cushion of the present invention are unlimited. The chair can have a headrest, arm rests, legs, and so forth. The claimed seat cushion can be used in any seating environment. It can be particularly suited to those users who are seated for extended periods of time, such as chairs in theatres, dentists' chair, chairs in hair salons, barber chairs, and chairs for home use, similar to those described below.
Seat cushion21, without a cover, is shown in greater detail inFIGS. 2 through 4 and6. Cushion21 includes a supportive,resilient base35.Base35, in an illustrated aspect of the invention, is comprised of polyurethane foam and shaped with appropriate contours to facilitate comfortable seating by the user, as known in the art.Base35 includes a cut out area orcavity37 and anair cell pad39 positioned incavity37. In general,cavity37 is formed in the bottom ofbase35 andair cell pad39 is introduced into the cavity and a foam layer or seal can be secured to the bottom of the base to keepair cell pad39 in place. In one aspect of the invention the thickness of the foam can range for ½ in to more than 3 inches, preferably 1½ inches to 2 inches or more. It will be appreciated that foam other than polyurethane foam can be employed, including, but not limited to viscoelastic foam or any other type of material that imparts the functional qualities of a foam.
In alternative embodiments of the invention, for example, as shown inFIG. 6,cavity37 can be formed in the top ofbase35 withair cell pad39 introduced from the top. In such an arrangement, there can be a thin layer offoam38 positioned over the air or, the air cell pad can be covered only bycover33. In yet another alternative embodiment, the cover can have an opening at the air cell pad, so that the air cell pad is exposed.
Air cell pad39 is located inbase35 at a position that places the air cell pad under the ischial area of a normally seated user. The ischial tuberosities are the lower portions of the hip bones and usually represent the area of greatest pressure on the buttocks of a seated user. Most discomfort experienced from prolonged seating is felt in the buttocks at the ischial area.
In any event,air cell pad39, shown in detail inFIG. 5, is comprised of aflexible base40 and an array ofindividual air cells42 arranged in rows of air cells across the base. In the illustrated embodiment, eachair cell42 is preferably an expandable, four fin cell preferably molded from neoprene. Any geometry of cell can be employed however, such as pyramidal shaped, cells having more than four fins, cubes or other useful shapes.
The geometry of the air cells, however, should provide minimal resistance to conformity to the shape of the buttocks of the seated user. In a preferred aspect of the invention, the air cells are approximately 2 inches in height. As seen inFIG. 3, the geometry of theair cells42 in array of air cells provides for a smooth transition between theair cell pad39 and surroundingbase35. Theindividual air cells42 are interconnected so that air introduced into one cell is distributed among the cells so as to equalize pressure within the cells.
As shown inFIG. 5, there is anair conduit46 connected to oneair cell42 at one end and a pump, shown asbulb pump48 inFIG. 4, at the other end.Air cell pad39 preferably can be molded from neoprene in accordance with the teachings of U.S. Pat. No. 4,541,136, which is incorporated herein by reference.Air cell pad39 also can be made from urethane or PVC or other plastic or moldable materials that can be used to make an air cell.
Base35 is enclosed incover33. In the illustrated embodiment, the top surface ofcover33 should stretch to deform under the seated user, ideally 250% by 170%. It is not necessary for the cover material over the sides of the seat cushion to stretch. The cover material at the top surface preferably also should be breathable. In the illustrated embodiment, the cover also enclosesair cell pad39.
It will be appreciated from the drawings that in the illustrated embodiment,bulb pump48 is located on one side ofseat cushion21,outside cover33 so as to be accessible to the user seated on the chair. The pump can be located in any convenient place on the chair as long as it is easily accessible by a seated user and is in fluid communication withair cell pad39. The pump actually could be under the cover, as shown inFIG. 4, yet accessible for actuation by depressing the cover and bulb, for example.Pump48 includes abulb50 and push button relief ofvalve52. The user can actuatebulb50 and pump air into the air cell pad and depresspush button valve52 to allow the release of air from the air cell pad. Although the illustrated embodiment employs a bulb pump, it is intended that any acceptable pump be encompassed by the present invention.
To achieve optimal benefit of the seat cushion of the present invention, the user sits on the cushion with the ischial area positioned overair cell pad39. The user then can actuatepump bulb50 and pump air into the air cell pad until that individual user is comfortable and well supported. Thecells42 deform under the buttocks and thighs to provide a maximum Air Floatation® support surface. The user also can allow air to escape through the valve until he or she reaches a desired immersion intoair cell pad39 to provide customized support surface. This support surface provides superior pressure relief over prior art seat cushions, as shown by pressure mapping illustrated inFIGS. 11 through 16, below. In any event, during use, if the user wants to change the immersion depth or seating characteristics, he or she can open the valve and adjust the air pressure withinair cell pad39.
FIGS. 7 and 8 illustrate another embodiment of a chair, indicated generally byreference numeral60 incorporating the seat cushion of the present invention. As shown,chair60 has a conventional external appearance, in this instance, including aseat62 for supporting seated user, abackrest64, aleft armrest66 and aright armrest68. As best seen inFIG. 8,chair60 can be configured as a lounge chair or reclining chair, commonly referred to as a recliner. In this configuration,chair60 includes aconventional reclining mechanism70 that operates to allowbackrest64 to lay back and aleg rest72 to elevate. Whenchair60 is fully reclined, the user is positioned in a nearly horizontal position. Of course, the backrest and leg rest can be positioned as desired so that the user can sit in any number of positions from fully upright (FIG.7) to fully reclined.
In any event,chair60 includes a seat cushion of the present invention indicated generally byreference numeral74 inFIG. 8.Seat cushion74 is enclosed inseat62.Seat cushion74 includes aresilient foam base76 and an inflatableair cell pad78.Base76 andair cell pad78 are constructed according to the principles set out above. It will be appreciated in a chair of the style ofchair60, thatseat62 may be of the conventional type with a frame, such as a wooden frame with padding, with springs or the like positioned under the padding. Hence, a cavity is formed in the padding, withbase76 andair cell pad78 positioned in the cavity. Alternatively,seat cushion74 can be installed inside the seat frame and replace any other padding.
Alternatively,air cell pad78 can be employed directly in a seat, withoutbase76, as will be explained below in reference toFIG. 9. In either embodiment, additional padding can be placed over the air cell pad, or just a thin layer of padding or foam placed over the air cell pad, and theentire seat62 is covered with upholstery, leather, vinyl or other appropriate cover material. It will be noted that the cover overair cell pad78 can be fashioned from the stretchy material described above.
As seen inFIG. 8,air cell cushion78 is connected to apump82 byair conduit84. Although a hand actuated pump similar to the one described above can be used, in the illustrated embodiment, pump82 is a small electric pump housed inside the bottom of the chair itself.Pump82 has acord86 for plugging into an electric outlet.Pump82 also is operatively connected to a control, indicated generally bycontrol88.Control88 is positioned on the exterior of the chair so as to be accessible by a seated user.Control88 is used to actuatepump82 so as to inflateair cell pad78 to taste.Control88 also can be provided with an indexing mechanism so that the user can setcontrol88 to an indicia or number, for example, that correspondence to a particular inflation pressure or firmness.
Chair60 also includes anair cell pad90 inbackrest64.Air cell pad90 is positioned within abase92, which can be a resilient foam base of the type described above or, alternatively, it can be a base comprising a substantially rigid frame with underlying support structure such as springs, as will be described below. There can be padding surrounding the base and air pad combination or the base and air cell pad can comprise the entire backrest. There can be a layer of padding on top of the air cell pad or a thin layer of foam or nothing at all.Backrest64 is enclosed in an appropriate cover material, including stretchy fabric over the air cell pad, if desired. In the illustrated embodiment,air cell pad90 is in fluid communication withpump82 byair conduit94. As with theair cell pad78,control88 can be used to select a firmness ofair cell pad90.
FIG. 9 illustrates aside chair100 includingseat102, abackrest104, andarmrests105. There is anair cell pad106 in abase108 withinseat102 and anair cell pad110 in abase112 withinback rest104. In this embodiment, each base comprises a substantially rigid frame positioned around the air cell pad to keep the air cell pads in position and the underlying springs or other support structure. In essence, in this embodiment the frame and the underlying support structure function as a non-resilient base and theair cell pads106 and110 are positioned in the base. These types of base and air cell pad combinations can be employed in any configuration of a chair, such aschair20 orchair60 and are shown only inchair100 for purposes of brevity and clarity.
FIG. 10 illustrates yet another embodiment of thereclining chair60 ofFIGS. 7 and 8. In this embodiment,chair60 includes anair cell pad120 in the arm rests66 and68 to provide enhanced support and comfort to the resting arms of a user. Moreover, there is anair cell pad122 inleg rest72 to provide enhanced support and comfort for the lower leg, for example the calves, of the seated user. There also can be an air cell cushion in a head and/or neck rest.
In any event the respective air cell pads, regardless of the location in the various chairs can be pre-inflated at the time of assembly or can be connected to a bulb type pump, or to an electric pump and controller of the types previously described, for inflation. The fact that the supportive characteristics of the base and pressure distributing pad configurations of the present invention, whether employed in a chair seat or a chair backrest, armrests or leg rests, can be provided in chairs of unlimited styles and configurations to enhance the support and comfort of a seated user.
It will also be appreciated that in addition to the air cell pads described above, the chairs can be equipped with support or pressure distributing pads having similar support and pressure distributing characteristics, such as single bladder inflatable pads, inflatable pillows, or gel-type pads. Gel pads, for example, have good support and pressure distributing characteristics and can be used in place of the air cell pads to impart desired support and pressure distribution characteristics to a chair. Hence, a pressure distributing pad, in the present invention, can include the air cell pads described above, or any other type of inflatable or gel-type support that can impart support and pressure relief characteristics to the chair seats, backrests, armrests or leg rests or any other section of a chair.
The pressure maps inFIGS. 11 through 16 are a visual representation of the force distribution on a seat cushion of the present invention, particularly that cushion shown inFIG. 1-6, versus a prior art office chair seat cushion designed to reduce pressure. The prior art cushion tested is the Ergogenesis Model No. J2507 (Ergogenesis, Navasota, Tex.). The prior art seat cushion is a contoured seat, based upon the concept of zero gravity posture that is designed to disperse the user's body weight over an increased surface area.
In creating the pressure maps approximately 35 to 40 mm Hg pressure was applied to the cushion by a seated load. The darkest areas of the black and white pressure maps, which correspond to the red areas of the color pressure maps, represent the areas of greatest pressure.FIGS. 11 and 12 illustrate the areas of 50 mm Hg pressure resulting from the force load on the prior art seat cushion (FIG. 11) and the cushion of the present invention (FIG. 12). As shown by the pressure maps, areas of resulting 50 mm Hg pressure appear on the pressure map ofFIG. 11, whereas none appear on pressure map ofFIG. 12.
FIGS. 13 and 14 illustrate the distribution of 40 mm Hg pressure or greater in the respective cushions under the force load. As can be seen inFIG. 13, the pressure map of the prior art cushion illustrates a significant area of pressure of 40 mm Hg or greater, whereas the cushion of the present invention again shows none.
Finally,FIGS. 15 and 16 show the distribution of 30 mm Hg pressure or greater under the force load. The pressure map of the prior art cushion,FIG. 15, shows an even greater area of pressure when measuring pressure of 30 mm Hg or more, whereas the cushion of the present invention, mapped inFIG. 16, shows relatively small areas of pressure of 30 mm Hg or greater under the force load.
It will be appreciated by comparing the darkest areas of the pressure maps in the black and white pressure maps, which correspond to the red color in the color pressure maps, that the seat cushion of the present invention reduces pressure, particularly at the ischial areas when measuring three different pressure distributions under a constant force load.
It will be appreciated that the foregoing description and accompanying drawings illustrate one representative aspect of the invention, including the best mode of working the invention presently known to the inventor. However, the specification should be viewed as illustrative of the broadest aspects of the invention and should not be construed in a limiting sense.