GB2161704A - Bath cushion - Google Patents

Abstract

A deformable cushion has a water-tight skin (1) and a displaceable filling (7). The filling (7) and hence the cushion as a whole is denser than water. It can be used to provide padding on an underwater surface such as a bath for people who do not wish to sit directly on the hard surface, e.g. people with bed-sores. Preferably the skin (1) is a PU/PVDC/PU laminate, embossed on the outside to provide a non-slip surface. The filling is preferably a mixture of silica, montmorellic clay, barytes, glycerol and a biocide. The faces of the cushion may be joined together in a number of places (5) giving a quilted appearance to the cushion, to promote an even distribution of the filling. <IMAGE>

Description

SPECIFICATION Cushion Some people suffer discomfort when taking a bath, because they have to sit on the relatively hard bath surface. This problem typically affects elderly, frail and sick people, and also people suffering from ulcers, bed-sores and other conditions which make it painful to sit on a hard surface. In some instances injury or the aggravation of an existing condition may result.

It has been proposed to avoid this problem by placing an inflatable cushion in the bath, on which the bather sits. The cushion has suckers to attach it to the bottom of the bath so as to prevent it from floating to the surface when the bath contains water.

In practice, this cushion is not ideal, as the suckers tend to come away from the bath surface so that the cushion is not held down to the bottom.

US 3892000 and US 4051563 each propose a liner for a bath which will cover not only the bottom of the bath but also the back and at least part of the sides of the bath. The liner in each case has a water filled section resting on the bottom of the bath.

Using water as filling serves to avoid gross positive buoyancy, but it is not material whether buoyancy is entirely absent or not because the liner is dimensioned to cover the entire floor of the bath and will be held in place by the weight of bath water on top of the liner.

US 2483077 proposes a bath cushion with a sponge rubber filling. Again, this will tend to float, and suckers are provided to hold it in place. US 3835483 proposes an inflatable bath cushion for the purpose of aiding a user to get out of a bath by obtaining lift from the cushion's buoyancy.

Many other cushions have been proposed in order to prevent or ease sores, but they are not intended for use immersed in water, and it is unlikely that they would be suitable for this purpose.

For instance, US 3721232 proposes a cushion filled with a water-based colloid gel. Inevitably this will have a density substantially equal to that of water, and so would not rest satisfactorily on the bottom of a bath even if it was otherwise suitable. Likewise, US 3968530 proposes a pad with a gel filling containing a lightweight aggregate such as expanded polystyrene beads. Such a pad will float on water. US 3308491, US 3663973, US 3737930 and US 3858379 all propose polymer-gel-filled cushions or pads which are not intended for use immersed in water. They are not likely to be suitable for such use, e.g. US 3737930 proposes a cover for the gel pad which is closed by a zip fastener and which therefore is not water-tight. Since the cushions or pads are not intended to be used in water, none of these specifications says whether the cushion or pad will sink or float.As a practical matter there is a general desire in the pressure-relieving-cushion art to minimise cushion weight, in order to make the cushions easy to handle. If these proposals are put into practice, the density of the filling, and thus the cushion buoyancy, is likely to be influenced strongly by the details of the gel-making process.

The present invention seeks to provide a better solution to the problem of hard baths. It provides a deformable cushion suitable for use immersed in water, the cushion having a flexible water-tight skin and a displaceable filling, the cushion as a whole being denser than water so that it will rest naturally on the bottom of a filled bath without the need for any securing means.

The skin is preferably a PU/PVDC/PU three-layer laminate. This material has a long life and does not tend to dry out or crack. Preferably the outer surface of the skin is roughened, e.g. embossed, so that it is "non-slip", although this feature is not necessary if the cushion is used in an outer cover e.g. of fabric.

Other materials are possible for the skin, but if the filling contains a liquid it is preferable that the skin is impervious to this liquid so that the cushion does not "sweat". "Sweating" (the permeation of filling liquid through the skin) is preferably avoided as it can make the cushion somewhat unpleasant to touch.

The cushion can be of any desired shape and size.

However, it is very strongly preferred that the cushion should have dimensions such that it can rest wholly submerged on the floor of a conventional bath, intended for human occupation without completely covering the floor of the bath. It will be apparent that with such a size water is free to percolate beneath the cushion. The fact that the cushion will remain on the floor of the bath even when the bath is unoccupied is due to the density of filling being greater than the density of water. For a cushion to be confined to the floor of a conventional bath it is appropriate that its length should be less than 80 or 90 cm while its width should be even less.

A square of about 15 ins x 15 ins (38 cm x 38 cm) has been found to be satisfactory in most uses.

Limiting the size also has the advantage that the total weight of the cushion does not become too great. An excessive weight would of course hinder removing the cushion from the bath after use. It is preferred that the cushion has a total weight which does not exceed 5 kg.

Although it is desired that the dimensions of the cushion should be such that it will not completely cover the floor of a conventional bath, this does not, however, mean that the cushion cannot be used in any other way. It can for instance be used on special baths for the bathing of infirm hospitai patients and can also be used on existing systems to lower aged or infirm hospital patients into a bath.

Satisfactory fillings can be made by mixing one or more powdered or granular solids with a liquid. I have found a mixture of silica, montmorellic clay, a biocide, barytes and glycerol to be suitable. The barytes is principally responsible for giving the cushion sufficient weight. The biocide may be a blend of partially chlorinated heterocyclic compounds. Expanded polystyrene beads may also be used as a cheap way of providing bulk for the filling, but care must be taken to see that the overall density of the cushion remains suitable.

The following is an example of a suitable filling composition: parts by weight Glyceroi B.P. Grade 100 Hydrated magnesium silicate 5.25 Afumed silica having a surface area of 200-400 m2gm~1 3.75 A biocide which is a blend of partially chlorinated heterocyclic compounds 0.5 Expanded polystyrene beads 3.09 Barytes powder 75 The density of this filling composition (and thus of a cushion filled with it) is about 1.08 times that of water.

The viscosity may be varied as desired by altering the proportions of the ingredients. The filling may be coloured with a suitable dye or pigment. Other liquids may be used instead of or as well as glycerol, e.g. other polyhydric alcohols, water or oils. Other thickeners may be used, e.g. alginates, polyacrylamides, modified starches, or sodium polyacrylate.

Other constituents are possible, but it is preferable to include a biocide, though not necessarily partially chlorinated heterocyclic compounds.

The total weight of a cushion 15 inches square might, for instance, be about 7 Ibs (3 kg). Preferably its overall density is between 1 and 1.5 times that of water, more preferably between 1 and 1.2.

Preferably the two opposed major surfaces of the cushion are connected to each other in a number of other places as well as around the edge of the cushion. If the skin is made of the laminate mentioned above, these connections may be spotwelds between the skin on either side of the cushion. This construction hinders movement of the filling without preventing it entirely. Thus when someone sits on the cushion, it will conform to the body and reduce the contact pressure as compared with sitting directly on the bath surface. However, the movement of the filling is hindered so that it will not entirely leave the area directly beneath the sitter, as if this happened the benefit of the cushion would be lost or reduced. For a 15 inch square cushion, 25 spot-welds, arranged in alternating rows of 4 and 3, are suitable.

If the skin is made of PU/PVDC/PU laminate, it may be manufactured by sealing together two sheets of the laminate around their edges, and also in other places (as mentioned above) if desired. This sealing may be carried out by any suitable method, e.g. by an adhesive, by heat-sealing, or by high-frequency welding. The skin is then filled.

It has been found convenient to provide the skin with plugable holes, e.g. two, through which the filling is introduced. Once the skin is filled, the holes are closed.

The cushion can be used with most existing baths without the need for any modification. The cushion can also be used on existing systems to lower the aged and infirm into a bath, thereby adding to their safety and minimising the worsening of skin conditions by reducing the incidence of pressure and abrasion damage.

The cushion may have connection means so that it can be connected to other like cushions, so as to increase the area covered. Thus two or three cushions could be connected so as to cover part of the bottom of a bath, an adjacent end of the bath and the rim of the bath at that end. In this way a person can lean back without placing their back and neck in direct contact with the hard bath surface.

The present invention also provides a method of alleviating the hardness of a surface on which a person rests when the surface is under water, the method comprising placing on the surface a cushion as described above. Typically the surface will be a surface of a bath or a part of apparaus for lowering the person into a bath or raising them out of it.

An embodiment of the present invention, given by way of example, will now be described with reference to the accompanying drawings, in which: Figure lisa plan view of a cushion embodying the present invention; and Figure 2 is a section along line Il-Il of Fig. 1.

A deformable cushion has a flexible water-tight skin 1,made up of an upper skin layer 1a and a lower skin layer 1 b. Each layer is a PU/PVDC/PU laminate. The layers 1 a, 1 b are attached to each other by welding around the edge 3 of the cushion, and also at a number of other places 5 distributed across the area of the cushion, giving the cushion a quilted appearance.

Within the skin is a displaceable filling 7.

Movement of the filling 7 is hindered but not prevented by the additional places 5 of attachment between the skin layers 1 a, 1 b. The composition of the filling 7 may be as exemplified above.

The cushion as a whole is denser than water, and will rest naturally on the bottom of a filled bath without the need for any securing means. If a person taking a bath uses the cushion to sit on in the bath, the cushion deforms so as to spread the load and reduce the contact pressure on the body, as compared with sitting directly on the bath surface.

The cushion is manufactured and filled through two plugable holes as described above.

Preferably the outer surface of each skin layer 1 a, 1 b is embossed or roughened to make it "non-slip".

In use the cushion is placed in a bath or on a system used to lower a person into a bath. When the cushion is immersed in water it has no tendency to float and thus retains its position stably.

Conveniently the cushion is about 15 inches (38 cm) square, and weighs about 7 lb (3 kg), having an overall density between 1 and 1.5 times the density of water, more preferably between 1 and 1.2 times the density of water.

Holes through the cushion may be made in some 5a of the places 5 of attachment between the skin layers 1 a, 1 b. The holes would be connection means, enabling two such cushions to be connected by a cord passing through the holes. The places 5a with the holes would usually be at the corners of the cushion. Other ways of connecting cushions, e.g.

clips, buckles or permanently attached straps or ribbons, are possible. The usefulness of connection means on the cushions is given above.

Claims (12)

1. A deformable cushion suitable for use immersed in a bath of water, the cushion having a water-tight skin and a displaceable filling, the filling of the cushion being denser than water so that the cushion will be denser than water and will rest naturally on the bottom of the bath of water in the absence of securing means.

2. A cushion as defined in claim 1 having a density of more than 1 and not more than 1.5 times that of water.

3. A cushion as defined in claim 1 or claim 2 in which the filling comprises a mixture of at least one granular or powdered solid and a liquid.

4. A cushion as defined in claim 3 in which the filling comprises a mixture of silica, montmorellic clay, barytes, glycerol and a biocide.

5. A cushion as defined in any one of the preceding claims having two opposed major surfaces connected to each other in a plurality of places not at the edge of the cushion.

6. A cushion as defined in any one of the preceding claims in which the skin is a polyurethane/polyvinyldichloride/polyurethane laminate.

7. A cushion as defined in claim 6 in which the skin comprises two sheets of the said laminate, the sheets being sealed to each other around their edges and at a plurality of other places.

8. A cushion as defined in any one of the preceding claims in which the exposed outer surface of the skin of the cushion is roughened.

9. A cushion substantially as herein described with reference to the accompanying drawings.

10. A method of alleviating the hardness of a surface on which a person rests when the surface is under water, the method comprising placing on the said surface a cushion as defined in any one of the preceding claims.

11. A method as defined in claim 10 in which the said surface is a surface of a bath.

12. A method as defined in claim 10 in which the said surface is a part of apparatus for lowering the said person into or raising the said person out of a bath.