GB2248388A - Fluid filled body support - Google Patents

Abstract

A sealed fluid filled support comprising a plurality of vertically extending, interconnected cells. Each cell may be a truncated pyramid increasing in cross-sectional area from its open base to the under-side of the top surface. The cells are inter-connected to allow free passage of the fluid from cell to cell. The combined area of the top supporting surfaces of the cells is between 50% and 70% of the area of the support. <IMAGE>

Description

SPECIFICATION SPECIFICATION FOR IMPROVED SUPPORT The present invention relates to supports for the human body, particularly cusnions, mattresses and the like.

One of tne most persistent problns in the care of handicapped people, particularly children, is to provide comfortable and hygienic seating/support material. Tnis problem is particularly acute for the non-ambulant patient.

An object of the present invention is to provide improved supports for the numan body and, Particularly, for handicapped people.

According to British patent application no. 8912347.4r a sealer fluid filled support for a human body comprises a plurality of vertically extending, inter-connected cells which have cross-sectional shapes consisting of straight sided figures with not more than six sides, the combined area of the cross-sectional snapes being between 30 % and 75 % of the area of the support.

It has now been found that supports providing even greater comfort to the human body can be formed according to the principles described in British patent application no. 8912847.4 by arranging that the vertically extending ceil walls are angled outwardly form vertical in the direction of the support surface.

Thus, the interior cross-sectional area of the cells increases towards the under-side of the supporting surface.

Accordingly, the present invention is a sealed fluid filled support for a human body comprising a plurality of upwardly extending inter-connected cells in which the cross-sectional area of a cell increases as measured progressively from the base of the cell to the under-side of the top, supporting surface of the cell.

With straignt sided cells having a horizontal supporting surface, the upwardly extending wall or walls defining the sides of the cell have an angle or angles of at least 10 from the vertical. Preferably these angles are in the range 10 to 30 . Above about 30 , for example 45 , the slope of the side walls is sucn that the rasps becore relatively separated and the volume of the cells is reduced to an extend that reduces the effectiveness of the support.

The snape of the cross-sections of the cells is not critical provided they increase towards the support surfaces. Preferably the shapes are regular, for example round or a regular straight sided figure of not more than six sides.

Particularly preferred supports according to the present invention comprise a plurality of truncated pyramids whose upper surfazes are substantially fiat and co-planar.

ine outside of the top surfaces of the cells provide the Support for the human body. They preferably lie in a plane parallel with the bases of the cells which, preferably, lie in one plane. If desired, the top surfaces of the cells and/or the bases of the cells can be arranged to form a curved surface so snaping t final support. Suitably the top surfaces of the cells are arranged close to each other and so shaped that they fill substantially all of the area ci che support.However, some free space between the top surfaces of the cells is desirably to allow each cell surface freedom of movement, thereby preventing t@@sion on the s@@@ of the supported human body. Preferably this free space @o@ms from 20 % to 40 % of the area of the support.

@re bases of tne cells may be formed from any suitable sheet material and thus form an outer wall of the cell. However, if desired, the base section can be open ar joined to another base unit cell which is capable of retaining the fluid within the support.

The shape of the base unit is not critical. In a preferred embodiment of the present invention a support is formed by joining two sets of cells to each other across their open bases.

Tn supports according to the present invention-are filled with a fluid which can pass freely between inter-connected cells.

Tn support provides a closed system for the fluid, which is preferably at, cr close to, atmospheric pressure. The preferred fluid is air.

Supports according to tne present invention have an inherent stiffness due to the varying cross-sectional areas of the individual cells. If it is desired to incresse this stiffness the inner volute of the cells may be completely or partially filled with open cell foam material. It is important that the presence of such a foam or any other additional filling material shall not prevent the free flow of the fluid within the support to all the individual ceas which it cQ-.orises.

In a preferred embodiment the cross-section shape of all the individual cells comprising w e support is hexagonal, thus causing the support to have uniform stiffness. If desired, different sections of the support may be provided with cells naving different cross-section shapes and/or different cross-sectional areas. This res@@ts in a support having varying degrees of stiffness in different sections.

@ne vertically extending inter-connected cells must have sufficient height in relation to theif cross-sectional area to provide the support with a sufficient vo@@@@ of enclosed fluid to support the patient.

@ne support @@y be formed from any flexible fluid tight material, for example, @eoprene rubber. The preferred materials are closed cell plastic foam materials so@d under the trade names Plastazote and Evazote. The supports or sections thereof can suitably be formed by a vacuum forming process form such materials.

jn drawing shows a part sectioned view of an embodiment of the present invention in which two identical sheets of Evazote closed cell foam (1 and 2) are formed into two identically snaped sheets (3 and 3A) according to the present invention. These are bonded together at their contacting edges (4) so that they are inter-connected through their open bases (5). When joining the two formed sneers, inter-connecting air ways (6) are provided so that air can freely pass between cells.

In tne empodiment shown in tie drawing the cross-sectional area of eac.n cell increases from the base (7) to under the under-side of the supporting surface (8) by a factor of 167 %. The side walls of the cells make an angle of 15 .

ne embodiment shown in the drawing as described is a seat cushion according to the present invention. Typically the overall thickness of this embodiment is between 50mm. and 100 mm. To make a cusnion or mattress or lower weight bearing potential, each oE the sheets 3 or 3A can be joined at their bases to G plain backing sneet leavlny airways to allow tne fluid in the cells so formed to puss freely between the cells.

Claims (6)

1) An improved support, for example a cushion or mattress.

The support is a sealed fluid filled support for the human body comprising a plurality of vertically extending interconnected cells, the top surface of which has a cross sectional area of between 30% and 75% of the area of the support.

2) The top surfaces of the cells are substantially flat and parallel to the base and are therefore easily deformed to conform witn the shape of a weignt (body) resting on them.

.) The side walls or the cells are deliberately not vertical. They are inclined at typically 10% inwards from the top to the base (roughly mushroom shaped cells).

rne inclined walls allow each cell to tilt in any direction when a weight is placed on the support surface. Tne inclined walls also reduce the upward pressure of the walls on the supported body.

4) The comoination of a number of interconnected cells each having a relatively large normally flat support surface and Inclined walls as described above, give a support system which readily conforms to the shape of a body resting on it with each cell exerting equal pressure.

AMENDMENTS TO THE CLAIMS HAVE BEEN FILED AS FOLLOWS 1 A sealed fluid filled support for a human body comprising a plurality of upwardly extending inter-connected cells in which the cross-sectional area of a cell increases as measured progressively from the base of the cell to the underside of the top supporting surface of the cell, the sum of the maximum cross-sectional areas of the cells forming the support being in the range 30% to 75% of the area of the support's upper supporting surface.

2 A support as claimed in claim 1 in which the cells are straight sided and the upwardly extending wall or walls defining the sides of a cell have an angle or angles of at least 100 from the vertical.

3 A support as claimed in claim 2 in which said angle or angles are in the range 100 to 300.

4 A support as claimed in any of the preceeding claims in which the cells are truncated pyramids.

5 A support as claimed in any of the preceding claims in which there is free space between the top surfaces of the cells which forms from 20% to 40% of the area of the support.

6 A support substantially as described herein with reference to the accompanying drawing.