SEAT CUSHION
A seat cushion comprises a relief portion to selectively provide cushioning to a user's sitz bones received when the user is seated on a seating surface. The selective cushioning provided by the relief portion to the user's sitz bones can be greater than cushioning provided by the remainder of the seat cushion to portions of the user's body other than the sitz bones. The relief portion can be in the form of a pair of relief pockets offset to be depressed below the second surface. A resiliency of the relief pockets is different from a resiliency of areas of the second surface surrounding the relief pocket. The first surface and the second surface of the seat cushion can be contoured so as to form a central core, a relief portion substantially surrounding the central core, and an outer portion defined so as to surround the relief portion.
The present application claims priority to U.S. Provisional Application 62/347,888, filed Jun. 9, 2016, and U.S. Provisional Application 62/410,504 filed Oct. 20, 2016, the entire contents of each of which is hereby incorporated by reference.
BACKGROUNDTraditional sitting postures assumed when using typical office seating such as chairs has, over time, a detrimental impact on an individual's health. Besides encouraging a sedentary lifestyle, traditional seating may create muscular or orthopedic discomfort for a person. A more healthful and active seating postures, such as those provided by the upright active-sitting seat of U.S. 2013/0306831 A1 assigned to the assignee of the present application may be beneficial to a user.
It is generally known that the gluteus maximus muscles, which provide cover to ischial tuberosity (also known as “sitz bones”) in a standing or upright position, do not provide any cover to the sitz bones in the seated position. Further, because weight is frequently placed on the sitz bones while seated, this may cause discomfort to a person.
SUMMARYIn an aspect, this disclosure is directed to a seat cushion, comprising a first surface providing a seating surface to sit on and a second surface opposite to the first surface. The second surface can have a pair of relief pockets. The relief pockets can be offset to be depressed below a plane of the second surface so as to provide cushioning to a user's sitz bones received when the user is seated on the seating surface at a location corresponding to the relief pockets. The second surface can have variable resiliency such that a resiliency of the relief pockets is different from a resiliency of areas of the second surface surrounding the relief pocket.
In another aspect, the first surface and the second surface can be contoured so as to form a central core defined about a seat axis, a relief portion extending around the seat axis so as to substantially surrounding the central core, and an outer portion defined so as to surround the relief portion. The relief portion can be configured to receive and provide cushioning to a user's sitz bones received when the user is seated on the seating surface. The relief portion can be deformable when a user's weight is supported by the seating surface. The deformation of the relief portion can be substantially greater than a deformation of the central core and/or the outer portion when a force equivalent to the user's weight is applied on the central core and/or the outer portion.
In a further aspect, a relief portion can be shaped and sized to selectively provide cushioning to a user's sitz bones received when the user is seated on the seating surface at a location corresponding to the relief portion. The selective cushioning provided by the relief portion to the user's sitz bones can be greater than cushioning provided by the remainder of the seat cushion to portions of the user's body other than the sitz bones that are in contact with the seating surface.
The details of one or more examples are set forth in the accompanying drawings and the description below. Other features, objects, and advantages will be apparent from the description and drawings, and from the claims.
With continued reference to
Continuing with
As is apparent, the seat cushion 130 is resilient relative to the seat pan 120 and at least some portions of the seat cushion 130 can flex when a load (a user's body weight) is placed thereon. In some examples, a substantial portion (e.g., greater than about 50% of the area) of the seat cushion 130 can be resilient relative to the seat pan 120. In other examples, the entirety of the seat cushion 130 can be resilient relative to the seat pan 120.
With reference to
With continued reference to
Advantageously, the seat cushion 10 according to the present embodiment is molded as a single piece, with variable resiliency at various portions of seat cushion 10, such that different portions of the seat cushion 10 deform at different rates when a force (e.g., body weight) is applied on the seat cushion 10 (e.g., as seen in
Referring again to
The relief pockets 20 of some exemplary embodiments may have a “shape memory” configured to permit the relief pockets 20 to support users of different body weights without having to customize the shape and size of the relief pockets 20 for each user. For instance, the relief pockets 20 may have an initial shape (shown by the solid lines in
Such selective cushioning can be achieved by an appropriate shape and size of the relief pockets 20. In one example, the relief pockets 20 are positioned to span a certain area of the second surface 14 so as to provide selective cushioning. For instance, the relief pockets 20 can occupy an area of between about 5% and about 50% of a total surface area of the second surface 14. Relief pockets 20 sized to occupy less than about 5% of the total surface area of the second surface 14 may not provide adequate cushioning and may be too firm, while relief pockets 20 sized to occupy greater than about 50% of the total surface area of the second surface 14 may result in the rest of the seat cushion 10 deforming more than a desirable amount under the user's body weight and thereby not providing adequate support. In some embodiments, the relief pockets 20 can occupy an area of about 20% for optimal cushioning of the sitz bones while providing adequate support to the remainder of the user's body in contact with the seat cushion 10.
In another example, the relief pockets 20 can be spaced such that the spacing between the two relief pockets 20 are at a certain desired value to provide selective cushioning to the sitz bones. In this example, the spacing is measured between the geometric centers of the two relief pockets 20. For example, the spacing between the relief pockets 20 corresponds to a sitz bone spacing of an adult male or female user such that on average, the user's sitz bones rest generally at the geometric center “c” of the relief pockets 20. In such examples, the geometric centers “c” of the relief pockets can have a spacing 42 of between about 4 inches and about 8 inches, for instance, about 6 inches. However, it is generally known that the spacing between sitz bones in some adult male users may have a standard deviation of up to about one inch toward each other relative to the average sitz bone spacing of adult male users. In such cases, the spacing 42 of the relief pockets 20 can be about 5 inches. Similarly, the spacing between sitz bones in some adult female users may have a standard deviation of up to about one inch away from each other relative to the average sitz bone spacing of adult female users. In such cases, the spacing 42 of the relief pockets 20 can be about 7 inches. Accordingly, the relief pockets 20 can be sized to accommodate a standard deviation of about +/−1 inch in the sitz bone spacing relative to the average sitz bone spacing in adult male and female users.
In such examples, the relief pockets 20 can have a thickness 28 of between about 20% and about 70% of thickness 30 of the seat cushion 10 to provide increased cushioning at locations corresponding to the relief pockets 20. Further, the relief pockets 20 may have a depth 38 of between about 5% and about 50% of an overall depth 48 of the seat cushion 10, and a width 32 of between about 5% and about 50% of an overall width 40 of the seat cushion 10. Such exemplary embodiments with optimal size and spacing of the relief pockets 20 can advantageously accommodate users of different sizes and weight (and corresponding variability in sitz bone spacing).
In the illustrated embodiment, the thickness 30 of the relief pockets 20 gradually varies in the depthwise direction (e.g., along depth 38), as seen in
Referring back to
Referring now to
The offset distance 242 is generally non-zero, and in some examples, extends between about 15 millimeters and about 35 millimeters, and preferably about 20 millimeters and about 25 millimeters. In the illustrated embodiment, the offset distance 242 is about 30 millimeters. In some such cases, the offset distance 242 permits the front edge 236 of the seat cushion 230 to act as a cantilevered edge, as the seat cushion is made of a material such as injection molded EVA. Such embodiments provide optimal amount of relief to the back of a user's legs while generally supporting the user's weight thereon.
As perhaps best seen in
With continued reference to
Referring to
The seat pan 320 can be disc-shaped and have a planar first surface 322 (e.g., top surface) on which a seat cushion 330 is positioned (e.g., attached adhesively, or by mechanical fasteners). The seat cushion 330 may have a contoured profile to permit selective cushioning of certain areas of a user's body (e.g., sitz bones), however, the seat pan 320 may not follow the contours the seat cushion 330. The seat pan 320 can be rigid relative to the seat cushion 330, and may thus act as a support surface for mounting the seat cushion 330.
In some such examples, the seat cushion 330 can have a central core 332. The central core 332 can be surrounded by a relief portion 336. The relief portion 336 can be surrounded by an outer portion 338. The seat cushion 330 can have a first surface 340 (e.g., top surface or an interior surface below the top surface) providing a seating surface for the user to sit on and a second surface 342 (e.g., bottom surface or an interior surface above the bottom surface) opposite to the first surface 340. The first surface 340 can be contoured such that a portion 344 of the first surface 340 corresponding to the central core 332 can be concave, and a portion 346 of the second surface 342 corresponding to the central core 332 can be convex or generally planar when viewed from a plane parallel to the seat axis 302 (e.g., when viewed from the front, as shown in
The relief portion 336 can be rotationally symmetric so as to substantially surround the central core 332, which may permit cushioning of sitz bones regardless of the rotational orientation in which the user is seated. The relief portion 336 can also be contoured to provide selective cushioning. For instance, the relief portion 336 can be contoured such that it deforms to a greater extent when a user's weight acts on the relief portion 336, relative to the deformation of the central core 332 and/or the outer portion 338 when a force equivalent to the user's weight acts on the central core 332 and/or the outer portion 338.
The relief portion 336 can be sized and positioned so as to accommodate different user sizes and sitz bone spacing (e.g., as described with respect to
As noted above, the relief portion 336 can be contoured so as to provide selective cushioning of certain areas (e.g., sitz bones) of the user's lower body. In an example, the first surface 340 corresponding to the relief portion 336 can be generally convex when viewed from a plane parallel to the seat axis 302. Correspondingly, the second surface 342 at a location corresponding to the relief portion 336 can be generally convex when viewed from a plane parallel to the seat axis 302. The contouring of the first surface 340 can advantageously result in receiving, and thereby making contact with the sitz bones, which may often be the lowest portion of the user's lower body when in a seated posture. Such contouring may permit the relief portion 336 to advantageously deform to a greater extent relative to areas surrounding the relief portion 336 (e.g., central core 332 and outer portion 338) when a user's weight is placed thereon, as described with respect to similarly contoured seat cushion 10 shown in
Referring again to
Advantageously, the seat cushion 330 can be formed as a unitary piece using injected molding a suitable material (e.g., EVA). Accordingly, the convex portions of the central core 332, the convex portions of the relief portion 336 and the contact portions 360 can be a single continuous surface contoured as described above.
Embodiments of the present disclosure provide several advantages. Seat cushions according to the disclosed embodiments provide selective cushioning such that the relief pockets provide cushioning to the sitz bones for the user which are frequently uncovered by the user's muscles (e.g., gluteus maximus) when the user is in a seated position. The seat cushions are made of injection molded EVA, which is durable and cost effective to fabricate. The seat cushions are of a generally unitary construction (e.g., made of a single piece) despite having selective or variable resiliency at various portions of the seat cushion, which reduces discomfort associated with seat cushions fabricated from several pieces of foam that are attached together. Further, the relief pockets of the seat cushions are sized to accommodate a variety of sitz bone spacing, and are fabricated from polymers that have a desired shape memory to accommodate a wide range of user weights without having to size the cushions for each individual user. Additionally, embodiments that include a waterfall edge design on the seat cushion additionally provide further cushioning of the underside of a user's thighs when seated in the active or upright position. Further, embodiments also permit the seat cushion to be used in any rotational orientation.
Various examples have been described. These and other examples are within the scope of the following claims.
Claims
1. A seat cushion, comprising:
- a first surface providing a seating surface to sit on; and
- a second surface opposite to the first surface, the second surface having a pair of relief pockets,
- the relief pockets being configured to provide cushioning to a user's sitz bones received when the user is seated on the seating surface at a location corresponding to the relief pockets, the second surface having variable resiliency such that a resiliency of the relief pockets is different from a resiliency of areas of the second surface surrounding the relief pockets.
2. The seat cushion of claim 1, wherein the relief pockets are adapted to receive a user's weight acting through the user's sitz bones when the user is seated on the seating surface, the relief pockets being deformable in response to the user's weight, the deformation of the relief pockets being greater than a deformation of the areas of the second surface surrounding the relief pockets, when a force equivalent to the user's weight is applied on the areas of the second surface surrounding the relief pockets.
3. The seat cushion of claim 2, wherein the relief pockets have an initial shape when the user is not seated on the seating surface, the resiliency of the relief pockets permitting the relief pockets return to their initial shape once a user seated in the seating surface rises from the seating surface.
4. The seat cushion of claim 2, wherein the areas surrounding the relief pockets have a deformation negligible relative to the deformation of the relief pockets, when the force equivalent to the user's weight is applied on the areas of the second surface surrounding the relief pockets.
5. The seat cushion of claim 1, wherein the seat cushion is fabricated as a unitary piece by molding a polymer material.
6. The seat cushion of claim 5, wherein the polymer material forms a closed-cell foam after fabrication of the seat cushion, the polymer material being ethylene-vinyl acetate.
7. The seat cushion of claim 5, further comprising a plurality of ribs provided on the second surface, the plurality of ribs facilitating flow of polymer material and heat transfer during fabrication.
8. A seat cushion, comprising:
- a first surface providing a seating surface to sit on;
- a second surface opposite to the first surface, the first surface and the second surface each being contoured so as to form: a central core defined about a seat axis, a relief portion extending radially around the seat axis so as to substantially surround the central core, the relief portion being configured to receive and provide cushioning to a user's sitz bones received when the user is seated on the seating surface, and an outer portion defined so as to surround the relief portion such that the relief portion is positioned radially between the central core and the outer portion, the relief portion being configured so as to be deformable when a user's weight is supported by the seating surface, the deformation of the relief portion being substantially greater than a deformation of the central core and/or the outer portion when a force equivalent to the user's weight is applied on the central core and/or the outer portion.
9. The seat cushion of claim 8, wherein the seat cushion is rotationally symmetric about the seat axis.
10. The seat cushion of claim 8, wherein the relief portion extends a 360 degrees surrounding the seat axis.
11. The seat cushion of claim 8, wherein the seat cushion has a thickness, and the relief portion has a relief portion thickness, the relief portion thickness being between about 20% and about 70% of the thickness of the seat cushion.
12. The seat cushion of claim 8, wherein the seat cushion is contoured such that the first surface corresponding to the corresponding to the central core being concave and a portion of the second surface corresponding to the central core being convex or generally planar when viewed from a plane parallel to the seat axis.
13. The seat cushion of claim 8, wherein the seat cushion is contoured such that the first surface of the seat cushion at a location corresponding to the relief portion being generally convex and the second surface of the seat cushion at a location corresponding to the relief portion being generally convex when viewed from a plane parallel to the seat axis.
14. The seat cushion of claim 8, wherein the relief portion having a relief portion width, and the seat cushion has a representative dimension, the relief portion width being between about 20% and about 70% of the representative dimension.
15. The seat cushion of claim 14, wherein the seat cushion is disc-shaped and the representative dimension is a radius.
16. A seat cushion, comprising:
- a first surface providing a seating surface to sit on;
- a second surface opposite to the first surface, the second surface having a relief portion,
- the relief portion being shaped and sized to selectively provide cushioning to a user's sitz bones received when the user is seated on the seating surface at a location corresponding to the relief portion,
- the selective cushioning provided by the relief portion to the user's sitz bones being greater than cushioning provided by areas other than the relief portion to portions of the user's body other than the sitz bones that are in contact with the seating surface.
17. The seat cushion of claim 16, wherein the relief portion occupies an area of between about 10% and about 50% of a total surface area of the second surface.
18. The seat cushion of claim 16, wherein the relief portion comprises a pair of relief pockets separated by a relief pocket spacing, the relief pockets having a generally asymmetrically shape, the relief pocket spacing corresponding to an average sitz bone spacing of an adult male or female user.
19. The seat cushion of claim 18, wherein the relief pockets are of a size configured to accommodate a standard deviation of about +/−1 inch relative to the average sitz bone spacing of an adult male or female user.
20. The seat cushion of claim 18, wherein the relief pockets have a depth of between about 5% and about 50% of an overall depth of the seat cushion, and a width of between about 5% and about 50% of an overall width of the seat cushion.
21. The seat cushion of claim 18, wherein the relief pockets have a thickness of between about 20% and about 70% of an overall thickness of the seat cushion.
22. The seat cushion of claim 21, wherein the thickness of the relief pockets being variable whereby, the thickness of the relief pockets being greater near a back edge of the seat cushion than the thickness of the relief pockets near a front edge of the seat cushion.
23. The seat cushion according to claim 21, wherein the seat cushion is supported by and/or connected to a seat pan of a pivot seat, the seat cushion having a front edge that contacts a portion of a user's thigh when a user is seated thereon, and the front edge of the seat cushion extending past a front edge of the seat pan, the front edge of the seat cushion being cantilevered relative to the seat pan.
24. The seat cushion of claim 23, wherein a substantial portion of the seat cushion is resilient with respect to the seat pan.
25. The seat cushion of claim 23, further comprising a one or more connectors located on the second surface of the seat cushion to permit connection of the seat cushion to the seat pan.
26. The seat cushion of claim 23, wherein the seat pan has a first surface contoured so as to generally conform to a contour of the second surface of the seat cushion.
27. The seat cushion of claim 26, wherein the seat pan has a seat pan depth and a seat pan width, and the seat cushion has a seat cushion depth and a seat cushion width, wherein the seat pan width generally equals the seat cushion width, and the seat pan depth is generally less than the seat cushion depth.
28. The seat cushion of claim 27, wherein a difference between the seat cushion depth and the seat pan depth being equal to an offset distance.
29. The seat cushion of claim 28, wherein the offset distance is generally constant along a widthwise direction between a right edge and a left edge of the seat cushion, the right edge and the left edge each being lateral to the front edge of the seat cushion.
30. The seat cushion of claim 23, wherein the seat pan has a generally planar first surface, and the seat cushion has a generally non-planar second surface.
Type: Application
Filed: Jun 9, 2017
Publication Date: Dec 14, 2017
Inventor: Martin Keen (Jamestown, RI)
Application Number: 15/618,448