TECHNICAL FIELD OF THE INVENTION
[0001] This invention relates to pressure relief cushions for supporting part of the body.
BACKGROUND
[0002] Such cushions are of particular value in the prevention of pressure sores in people
such as the disabled or geriatric, who are obliged to remain in one position for long
periods of time.
[0003] US Patent No. 4 391 466 and European Patent No. 0 284 294 disclose known forms of
chair which incorporate pressure relief cushions.
[0004] An aim of the present invention is to provide a from of pressure relief cushion which
is patentably different from existing cushions.
SUMMARY OF THE INVENTION
[0005] The present invention proposes a pressure relief cushion as set forth in the appended
Claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] The following description and the accompanying drawings referred to therein are included
by way of non-limiting example in order to illustrate how the invention may be put
into practice. In the drawings:
Figure 1 is a general exploded view of part of a water chair, including two cushions of the
invention,
Figure 2 is a general view of a water cell for use with the chair of Fig. 1,
Figure 3 is a transverse section through the water cell as used in an upright cushion,
Figure 4 is a general view of an alternative form of seat cushion for the water chair of Fig.
1, and
Figure 5 is a general view of a cushion of the invention as incorporated in a divan.
DETAILED DESCRIPTION OF THE DRAWINGS
[0007] Referring firstly to Fig. 1, the water chair comprises a generally horizontal seat
portion 1 and an upright back-rest portion 2. Each portion 1, 2 is provided with a
support cushion 3, 4 respectively. Each support cushion includes a planar carrier
10 of relatively rigid plastics sheet which is secured to the frame of the chair by
nails 11, staples or the like. It will be appreciated that the carrier could also
be of hardboard, plywood or other stiff sheet material. A series of horizontally extending
sleeves 12, extending from side-to-side of the chair, are formed from a flexible sheet
13 of cotton, gabardine, canvas or like material, which is secured to the carrier
10 by a series of parallel rows 14 of stitching, staples or similar means. The width
of the strips of the sheet 13 defined between the rows of stitching 14 is greater
that the linear distance between the rows 14, so that the sleeves can each receive
a respective elongate cell 15, one of which will now be described with reference to
Fig. 2.
[0008] Each cell 15 comprises a backing sheet 16 of relatively rigid water-impermeable plastics
such as pvc, to which a front body-support sheet 17 of relatively flexible pvc or
other water-impermeable plastics is secured by heat welding 18 around the periphery
of the sheet 17. The support sheet 17 is either pre-shaped and/or is sufficiently
flexible to form an internal space between the sheets 16 and 17 which is partially
pre-filled with water prior to sealing the cell. The space is generally filled to
between 65% and 98% of its maximum volumetric capacity depending on the application
and position of use of the cell.
[0009] Each cell 15 is slid longitudinally into one end of the respective sleeve 12. The
transverse width of each backing sheet is slightly less than the distance between
the lines of stitching 14, and the width of the flexible front sheet of the sleeve
12 is dimensioned to hold the cell against lateral movement. Longitudinal movement
of the cell may be prevented by providing end portions 20 of the backing sheet 16
which project from each end of the sleeve 12 and are releasably secured to the carrier
10 by press-studs 21, hook-and-loop fasteners or the like.
[0010] In the case of the cushion 4, which is disposed in an upright, rearwardly inclined
position in use, the backing sheet 16 provides integral support for the cell 15 which
helps to maintain the shape of the cell as shown in Fig. 3. The cell thus has a less
pendulous shape in transverse section than has hitherto been possible for a cell of
similar dimensions and filled capacity. The cells are easily removed when required
by releasing the fasteners 21 and sliding the cells out of the sleeves 12, and the
rigid backing sheet 16 allows the cells to be easily re-inserted. This is very important
to allow thorough cleaning.
[0011] In practice, the cushions will usually have a decorative further outer covering of
cotton or the like.
[0012] It will be appreciated that the sheets 16 and 17 could be secured by means other
than heat welding, such as by using a suitable adhesive for example. Also within the
scope of the present invention, the rear wall of the cell could be formed by a rear
panel of flexible sheet material bonded to an outer layer of stiff board. The rear
wall could also be formed of two superimposed panels of flexible sheet with a sheet
of stiff board sandwiched between them.
[0013] Instead of water, the cell could be partially filled with another liquid or a viscous
gel.
[0014] The cell could furthermore be provided with a valve or a capped opening 24 (Fig.
2) to permit drainage and refilling of the cell. This would also allow the volumetric
contents of the cell to be adjusted after filling, if desired.
[0015] In the case of a generally horizontal cushion, as used with the seat portion 1, the
cells 15 and sleeves 12 could run from front-to-back of the chair if desired, as shown
in Fig. 4. The carrier 10 could also be curved as in the case of the divan illustrated
in Fig. 5. It will also be appreciated that the cushion could form a separate entity
which can be placed on a conventional seat, bed or the like.
[0016] The backing portion 16 provides integral support for the cell, which determines the
shape of the cell to a large extent whilst still permitting the body-support portion
17 to conform to the shape of the human body. The cell need not be secured within
the sleeve in all cases. The carrier may be secured to or form part of the back or
seat of a multi-seater chair such as a settee. The cushion could also form the support
surface of a bed.
1. A pressure relief cushion comprising a substantially rigid carrier (10) and at least
one relatively flexible layer (13) secured thereto to form a sleeve, the or each sleeve
having a cell (15) inserted therein which comprises an envelope partially filled with
a liquid or gel,
characterised in that the said envelope comprises a flexible body-support portion
(17) and a relatively rigid backing portion (16).
2. A pressure relief cushion according to Claim 1, in which the backing portion (16)
of the or each cell is substantially planar.
3. A pressure relief cushion according to Claim 1 or 2, in which the backing portion
(16) projects from at least one end of the sleeve and said projecting portion (20)
is releasably secured to the carrier (10).
4. A pressure relief cushion according to Claim 3, in which the backing portion (16)
projects from opposite ends of the sleeve and said projecting portions (20) are both
releasably secured to the carrier (10).