GB2117235A

GB2117235A - A back support cushion

Info

Publication number: GB2117235A
Application number: GB08208891A
Authority: GB
Inventors: Harry David Nicholas Webster
Original assignee: Individual
Current assignee: Individual
Priority date: 1982-03-26
Filing date: 1982-03-26
Publication date: 1983-10-12
Also published as: GB2117235B

Abstract

A back support cushion, for location against the lower part of the back-rest of a chair, comprises a resilient front portion 12 having a front surface shaped to engage and support the lumbar region of a person sitting on the chair, and a rear portion 11 to which the front portion is secured, the rear portion being formed of a harder material than the front portion and extending to the lower extremity of the cushion so as to rest on the seat portion of a chair on which the cushion is located, and thereby support the cushion. Sandwiched between the two portions 11, 12 of the cushion is an inflatable assembly 15 comprising a plurality of separately inflatable pockets (16, 17, Fig. 2), whereby the surface contour of the front portion 12 of the cushion may be varied by varying the extent of the inflation of the assembly. <IMAGE>

Description

SPECIFICATION A back support cushion The invention relates to back support cushions, by which is meant cushions designed to be located against the lower part of the back-rest of a chair to provide additional support for the lumbar region of a person using the chair. As is well known, most chairs do not provide adequate lumbar support and the use of an additional back support cushion can overcome this deficiency and reduce the incidence of back pain due to the lack of proper lumbar support.

However, many currently available forms of back support cushion are, due to their design, comparatively ineffective in providing the necessary support. One major difficulty arises in ensuring that the cushion is correctly located against the back-rest of the chair. Since the cushion needs to be fairly soft there is a tendency for it to collapse into the angle between the backrest and seat of the chair, or to be forced gradually into that angle by movement of the user. If the cushion collapses or is forced into this position it becomes ineffective for providing lumbar support and can even exacerbate back problems. In an effort to overcome this problem cushions are frequently provided with straps for securing the cushion to the back-rest of a chair, but these are comparatively ineffective since the cushion will still move over a period of time.

Back support cushions are commonly inflatable.

While this permits some variation in the shape and hardness of the cushion, thus permitting adjustment according to the requirements of the user, certain disadvantages arise. For example, an inflatable cushion does not provide adequate lumbar support on a car seat since sideways swaying movement of the user will simply squeeze air out of one side of the cushion and into the other, thus tending to exaggerate the sway rather than provide the necessary support.

The present invention sets out to provide an improved form of back support cushion which may overcome both of the problems referred to above.

According to the invention a back support cushion, for location against the lower part of the back-rest of a chair, comprises a resilient front portion having a front surface shaped to engage and support the lumbar region of a person sitting on the chair, and a rear portion to which the front portion is secured, the rear portion being formed of a harder material than the front portion and extending to the lower extremity of the cushion so as to rest on the seat portion of a chair on which the cushion is located, and thereby support the cushion.

Since the harder rear portion forms the lower extremity of the cushion, it will rest on the chair seat and prevent the cushion collapsing or being gradually forced into the angle between the chair back and seat.

Preferably the front portion and rear portion are substantially co-extensive over the whole area of the cushion. Alternatively, the rear portion may project downwardly beyond the lower extremity of the front portion.

The front portion of the cushion is preferably formed from resilient foamed plastics material.

The rear portion may also be formed from foamed plastics material, but of a harder form of such material. The two portions may be bonded together, for example by an adhesive, over substantially the whole common area thereof.

There may be sandwiched between the two portions of the cushion an inflatable assembly whereby the surface contour of the front portion of the cushion may be varied by varying the extent of the inflation of the assembly. The inflatable assembly preferably comprises a plurality of separate inflatable pockets whereby the contour of various parts of the surface of the front portion may be adjusted relatively to one another by differential inflation of the pockets. The pockets may be provided with separate inflation valves which project through apertures in the rear portion of the cushion.

The cushion may include a removable flexible cover to envelop the front and rear portions thereof. Means, such as straps, may be provided on the cover to locate the covered cushion on a chair. As previously mentioned, the formation of the cushion in two parts locates the cushion vertically against the back-rest, but the straps may be required to prevent the cushion moving forwardly away from the back-rest.

The following is a more detailed description of an embodiment of the invention, reference being made to the accompanying drawings in which: Figure 1 is a vertical section through a back support cushion according to the invention, in position on a chair, and Figure 2 is a front view of the cushion shown in Figure 1.

Referring to Figure 1, the cushion 10 comprises a rear portion 11 to which a front portion 12 is bonded, for example by means of an adhesive. The rear portion 11 is substantially planar whereas the front portion is moulded so that its front surface has a contour of the kind generally accepted as providing the best form of lumbar support for a user. That is to say, the surface is concavely curved in horizontal cross-section to provide support at the sides of the lower back, and convexly curved in vertical section so as to conform to the recommended shape of the lower back when sitting.

Both portions 11 and 12 are moulded from resilient foamed plastics material, but the material of the rear portion 11 is harder than the material of the front portion 12. The rear portion 11 is substantially co-extensive with the front portion 12 and provides the lowermost edge of the cushion so that, in use, it is the lower edge of the harder rear portion 11 which rests on the seat 13 of the chair. The harder rear portion 11 thus acts as a support for the softer front portion 12 and prevents the softer portion collapsing or being gradually forced into the angle between the chair seat 13 and the chair back 14.

As mentioned above, the portions 11 and 1 2 are secured together. However, an inflatable assembly 1 5 is sandwiched between the two portions towards the lower end of the cushion, as best seen from Figure 2. The inflatable assembly 1 5 is a unit formed from two layers of sheet rubber or plastics welded together along lines to form two spaced vertical side pockets 1 6 connected by two spaced horizontal pockets 17.

Each pocket is provided with an individual valve for inflating the pocket, each valve, such as the valve 18 shown in Figure 1, passing through an aperture 19 in the rear portion 11 of the cushion.

By differentially inflating the pockets 1 6 and 17, the contour of the front surface of the portion 12 of the cushion may be adjusted according to the exact requirements of the user. By adjusting the extent of inflation of the side pockets 1 6 the amount of side support given to the user can be varied, whereas by adjusting the inflation of the horizontal pockets 1 7 the vertical curvature of the cushion may be adjusted to give the best possible support for a particular user. The valves 1 8 may be of the well known type where the mouthpiece may be withdrawn for inflation and then sealed with a cap before being depressed flush with the surface from which it was withdrawn.

The two portions of the cushion may be formed in a single mould by a two-stage moulding process. There may be provided an open-topped mould, of the required area of the cushion, having its lower surface shaped according to the required contour of the front surface of the front portion 12.

The lower part of the mould is then filled with low density foam plastics material and when this is set the inflatable assembly 1 5 is located in the appropriate position on the plastics material. A layer of higher density, and thus harder, foamed plastics material is then introduced into the upper part of the mould to form the layer 11 over the assembly 1 5. An adhesive may be required to secure the two layers together but in some cases the high density layer may bond itself adequately to the lower layer as it is introduced into the mould.

'Although the rear layer 1 1 is shown as being co-extensive with the front portion 12, it will be appreciated that one layer could overlap the other layer, provided that the harder rear portion 11 forms the lower edge of the cushion to prevent the cushion collapsing as described above.

The two portions 11 and 1 2 of the cushion may be enclosed in known manner within a fabric cover 20, a zip fastener being provided along one side of the cover to permit its removal for washing.

As shown in Figure 2, straps 21 may be provided on the cover 20 so that the straps may be passed around the chair back 14. It should be stressed, however, that the purpose of such straps is merely to prevent the cushion from falling away from the chair back 14 and the straps are not required to locate the cushion vertically. As previously explained this is achieved by the inclusion of the harder rear support portion 11 in the cushion.

Claims

1. A back support cushion, for location against the lower part of the back-rest of a chair, comprising a resilient front portion having a front surface shaped to engage and support the lumbar region of a person sitting on the chair, and a rear portion to which the front portion is secured, the rear portion being formed of a harder material than the front portion and extending to the lower extremity of the cushion so as to rest on the seat portion of a chair on which the cushion is located, and thereby support the cushion.

2. A back support cushion according to claim 1, wherein the front portion and rear portion are substantially co-extensive over the whole area of the cushion.

3. A back support cushion according to claim 1, wherein the rear portion projects downwardly beyond the lower extremity of the front portion.

4. A back support cushion according to any of claims 1 to 3, wherein the front portion of the cushion is formed from resilient foamed plastics material.

5. A back support cushion according to any of claims 1 to 4, wherein the rear portion is formed from foamed plastics material.

6. A back support cushion according to any of claims 1 to 5, wherein the front and rear portions are bonded together over substantially the whole common area thereof.

7. A back support cushion according to claim 6, wherein the front and rear portions are bonded together by an adhesive.

8. A back support cushion according to any of claims 1 to 7, wherein there is sandwiched between the two portions of the cushion an inflatable assembly whereby the surface contour of the front portion of the cushion may be varied by varying the extent of the inflation of the assembly.

9. A back support cushion according to claim 8, wherein the inflatable assembly comprises a plurality of separate inflatable pockets whereby the contour of various parts of the surface of the front portion may be adjusted relatively to one another by differential inflation of the pockets.

10. A back support cushion according to claim 9, wherein the pockets are provided with separate inflation valves which project through apertures in the rear portion of the cushion.

11. A back support cushion according to any of claims 1 to 10, including a removable flexible cover to envelop the front and rear portions of the cushion.

12. A back support cushion according to claim 1 1, wherein straps are provided on the cover to locate the covered cushion on a chair.

13. A back support cushion substantially as hereinbefore described with reference to the accompanying drawings.