GB2181048A - Overlay - Google Patents

Abstract

An overlay for a bed mattress or seat cushion comprising a layer of foam (11) having a sculpted upper surface providing spaced protrusions or apices (12) and covered with a fire retardant fabric (14) held in a state of tension. <IMAGE>

Description

SPECIFICATION Overlay This invention concerns an overlay for a bed mattress or seat cushion as of a wheel-chair for example, particularly, though by no means exclusively, suitable for use in hospitals or similar establishments, primarily for the prevention or relief of the symptoms of decubitus ulcers, more commonly known as 'bed-sores'.

It has been known to overlay a bed mattress with a sheet of synthetic foamed plastics material whose upper surface has been moulded, cut, sculpted or otherwise formed to provide a multiplicity of mutually spaced protrusions or apices which may extend from a planar surface or be separated by intermediate nadirs. Such an overlay, which will be referred to hereinafter as an overlay of the kind referred to, is efficacious in that it relieves pressure on the bony prominences of the body and encourages air circulation with attendant dispersal of heat and moisture at the points of contact with the body.

Overlays of the kind referred to have however not been in widespread use, at least in the United Kingdom, since they have, in the main failed to pass, even when of the better fire retardant foams commercially available, appropriate test specifications such as Crown Supplies Fire Test Specification No. 5 (Crib No. 5) of November 1982.

The present invention is based on the discovery that if an overlay of the kind referred to is covered with a fire retardant fabric which is in a state of tension the combination will, in fact, pass such tests.

Thus according to the present invention there is provided an overlay of the kind referred to having a cover of flame retardant fabric tensioned thereover.

The cover may take the form of a close-fitting baglike enclosure encapsulating the overlay or a fitted sheet having elasticated corners.

The invention will be further apparent from the following description with reference to the figures of the accomqanying drawing, which show, by way of example only, one form of the mattress overlay embodying the invention.

Of the drawing: Figure 1 shows a perspective view of the overlay; and Figure 2 shows a cross-section through the overlay on the line Il-Il on Figure 1 Referring now to the drawing it will be seen that the overlay, generally indicated at 10 is of rectangular shape suited to be positioned on a standard single hospital bed having a length 1 of 182 cm or thereabouts and a width w of 76 cm or thereabouts.

The overlay is readily portable being light in weight and easily rolled.

The overlay comprises in combination a pad 11 of foamed synthetic plastics material such as of polyurethane and preferably incorporating flame retardant additives.

The upper surface of the pad 11 is sculpted to provide a multiplicity of protrusions or apices 12 mutually spaced and separated from one another by intermediate nadirs 13. Typically the overall thickness of the pad 11 may be 7.5 cm or thereabouts and the depth of the nadirs from the upper extremities of the apices 3.75 cm or thereabouts.

The pad 11 is provided with a cover 14 in the form of a fitted sheet whose general shape is that of a shallow rectangular box lacking one of its major faces, and sized such that when fitted in position on and over the pad 11 its upper surface is tensioned over the apices 12. This effect can be enhanced and ensured by the provision of elasticated corners-as well known from conventional bedding.

The cover 14 is fabricated from a flame retardant fabric capable of laundering without immediate ioss of its flame retardant properties.

The pad 11 can, of course, be cleaned and sterilized a number of times by autoclaving.

It will be appreciated that it is not intended to limit the invention to the above example only, many variations, such as might readily occur to one skilled in the art, being possible, without departing from the scope thereof.

The cover may take the form of a closely fitting bag-like enclosure which becomes tensioned on account of the resilience of the overlay.

Overlays of smaller size may be provided suitable for use over seat cushions such as those of wheelchairs for example.

1. An overlay of the kind referred to having a cover of flame ratardentfabric tensioned thereover.

2. An overlay according to claim 1, wherein said cover is in the form of a fitted sheet sized to ensure that it is tensioned over the protrusions or apices of the overlay.

3. An overlay according to claim 2, wherein the fitted sheet has elasticated corners.

4. An overlay according to any preceding claim sized to fit on a bed mattress.

5. An overlay according to any one of claims 1 to 3, sized to fit on a seat cushion.

6. An overlay of the kind referred to substantially as described herein with reference to the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (6)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Overlay This invention concerns an overlay for a bed mattress or seat cushion as of a wheel-chair for example, particularly, though by no means exclusively, suitable for use in hospitals or similar establishments, primarily for the prevention or relief of the symptoms of decubitus ulcers, more commonly known as 'bed-sores'. It has been known to overlay a bed mattress with a sheet of synthetic foamed plastics material whose upper surface has been moulded, cut, sculpted or otherwise formed to provide a multiplicity of mutually spaced protrusions or apices which may extend from a planar surface or be separated by intermediate nadirs. Such an overlay, which will be referred to hereinafter as an overlay of the kind referred to, is efficacious in that it relieves pressure on the bony prominences of the body and encourages air circulation with attendant dispersal of heat and moisture at the points of contact with the body. Overlays of the kind referred to have however not been in widespread use, at least in the United Kingdom, since they have, in the main failed to pass, even when of the better fire retardant foams commercially available, appropriate test specifications such as Crown Supplies Fire Test Specification No. 5 (Crib No. 5) of November 1982. The present invention is based on the discovery that if an overlay of the kind referred to is covered with a fire retardant fabric which is in a state of tension the combination will, in fact, pass such tests. Thus according to the present invention there is provided an overlay of the kind referred to having a cover of flame retardant fabric tensioned thereover. The cover may take the form of a close-fitting baglike enclosure encapsulating the overlay or a fitted sheet having elasticated corners. The invention will be further apparent from the following description with reference to the figures of the accomqanying drawing, which show, by way of example only, one form of the mattress overlay embodying the invention. Of the drawing: Figure 1 shows a perspective view of the overlay; and Figure 2 shows a cross-section through the overlay on the line Il-Il on Figure 1 Referring now to the drawing it will be seen that the overlay, generally indicated at 10 is of rectangular shape suited to be positioned on a standard single hospital bed having a length 1 of 182 cm or thereabouts and a width w of 76 cm or thereabouts. The overlay is readily portable being light in weight and easily rolled. The overlay comprises in combination a pad 11 of foamed synthetic plastics material such as of polyurethane and preferably incorporating flame retardant additives. The upper surface of the pad 11 is sculpted to provide a multiplicity of protrusions or apices 12 mutually spaced and separated from one another by intermediate nadirs 13. Typically the overall thickness of the pad 11 may be 7.5 cm or thereabouts and the depth of the nadirs from the upper extremities of the apices 3.75 cm or thereabouts. The pad 11 is provided with a cover 14 in the form of a fitted sheet whose general shape is that of a shallow rectangular box lacking one of its major faces, and sized such that when fitted in position on and over the pad 11 its upper surface is tensioned over the apices 12. This effect can be enhanced and ensured by the provision of elasticated corners-as well known from conventional bedding. The cover 14 is fabricated from a flame retardant fabric capable of laundering without immediate ioss of its flame retardant properties. The pad 11 can, of course, be cleaned and sterilized a number of times by autoclaving. It will be appreciated that it is not intended to limit the invention to the above example only, many variations, such as might readily occur to one skilled in the art, being possible, without departing from the scope thereof. The cover may take the form of a closely fitting bag-like enclosure which becomes tensioned on account of the resilience of the overlay. Overlays of smaller size may be provided suitable for use over seat cushions such as those of wheelchairs for example. CLAIMS

1. An overlay of the kind referred to having a cover of flame ratardentfabric tensioned thereover.

2. An overlay according to claim 1, wherein said cover is in the form of a fitted sheet sized to ensure that it is tensioned over the protrusions or apices of the overlay.

3. An overlay according to claim 2, wherein the fitted sheet has elasticated corners.

4. An overlay according to any preceding claim sized to fit on a bed mattress.

5. An overlay according to any one of claims 1 to 3, sized to fit on a seat cushion.

6. An overlay of the kind referred to substantially as described herein with reference to the accompanying drawings.