GB2146241A

GB2146241A - Hospital bed

Info

Publication number: GB2146241A
Application number: GB08324358A
Authority: GB
Inventors: Charles Barnes
Original assignee: Doherty & Sons Ltd Edward
Current assignee: Doherty & Sons Ltd Edward
Priority date: 1983-09-12
Filing date: 1983-09-12
Publication date: 1985-04-17
Also published as: GB8324358D0

Abstract

In order to hold the backrest (14) of a hospital bed in any selected position of inclination on a frame (18), holding means are pivotally connected between a plate or bracket (22) of the backrest and a cross-girder or bracing member (24) on the frame (18). The holding means take the form of a "gas strut" comprising a gas-containing cylinder (26) having a piston (28) provided with a piston rod (30) which is pivotally connected at (32) to the plate (22). The end of the gas cylinder (26) remote from the piston rod (30) carries a resilient buffer (36) and valve means (38) which are under the control of a release lever (40) which can easily be operated by a patient on the bed to release the hold of the holding means. However, to permit the backrest to be moved quickly from an inclined position to a horizontal position if the patient is having a heart-attack, the holding means has provision for the build- up of gas pressure in the cylinder (26) to be released as the backrest is forced downwards, without actuation of the lever (40). This can be effected by a pressure-release valve in the piston (28). <IMAGE>

Description

SPECIFICATION Hospital bed This invention relates to hospital beds of the kind having mattress platforms.

In our co-pending Patent Application filed on the same day as the present Application we have described a hospital bed in which part of the mattress platform is arranged to be pivotally mounted on a supporting rectangular frame so that it can be swung upwards into a position where it serves as a backrest. The present invention is concerned with means which allow the backrest to be held in a desired position of inclination but which also permits the backrest to be forced downwards rapidly, i.e., into its normal horizontal position, without the need for a release lever to be operated. This is important in those cases where the patient has a heart condition and it suddenly becomes necessary for the backrest to be moved quickly from an inclined position to its horizontal position.

With this need in view, the present invention is concerned with a hospital bed having a pivotally-mounted backrest which is held in any selected position of inclination by holding means provided with a release lever positioned so that the lever can easily be operated by a patient in the bed, the said holding means comprising a so-called gas strut in the form of a cylinder and piston containing gas under pressure which is adapted to allow the backrest to be forced down quickly into its horizontal position without actuation of the release lever.

An example of a hosital bed in accordance with the invention is shown in the accompanying drawings, in which: Figure 1 is a diagrammatic perspective view from above of the mattress platform and its supporting frame; Figure 2 is a view similar to Fig. 1 showing part of the mattress platform in a raised position whereby it serves as a backrest; and Figure 3 is an enlarged side view of holding means on the bed for holding the backrest portion of the mattress platform in any selected position of inclination.

Hospital beds frequently comprise a onepiece matress platform which is bounded and supported by a rectangular metal frame. In the case of the bed shown in the drawings, however, the mattress platform 10 comprises a main portion 1 2 and a secondary portion 1 4 which is pivotally mounted at 16 on the supporting frame 1 8 so that it can be swung upwards out of the horizontal position shown in Fig. 1 into the inclined position shown in Fig. 2 where it serves as a backrest.Further, in accordance with the invention described in the co-pending Application referred to above, the frame 1 8 is so mounted on the bed that raising of the backrest portion 14 of the platform 10 causes the frame to be tilted into a "feet-up" position so that it lies at a small angle a to the horizontal. Preferably this angle is substantially 4" when the backrest portion 14 is in the position shown in Fig. 2, but in practice it can be anywhere between 1" and 10".

In order to hold the backrest 14 in any selected position of inclination on the frame 18, holding means 20 are pivotally connected between a plate or bracket 22 welded or otherwise attached to the lower portion of the backrest and a cross-girder or bracing member 24 on the frame 18 as shown in Fig. 3. The holding means 20 take the form of a so-called "gas strut" comprising a gas-containing cylinder 26 having a piston 28 provided with a piston rod 30 which is pivotally connected at 32 to a nose portion 34 on the plate or bracket 22. The end of the gas cylinder 26 remote from the piston rod 30 carries a resilient buffer 36 made of synthetic rubber and valve means 38 which are under the control of a lever 40 which can easily be operated by a patient on the bed to release the hold of the holding means 20 on the backrest.In this way the backrest can be readily moved into and out of any particular position and be held in any such position by the releasable holding means 20. The valve means 38,which form an extension of the cylinder 26, are pivotally mounted at 42 on a bracket or lug 44 welded or otherwise secured to the cross-girder 24 on the frame 1 8.

The internal construction of the gas cylinder 26 and the construction of the valve means 38 is such that the piston 28 is "stiff" within the cylinder (due to gas pressure within the latter) when the lever 40 is in its "off" or "non-release" position. Such is the stiffness of the cylinder and piston in those circumstances that the backrest 1 4 is held firmly in any selected position of inclination. When the lever 40 is moved into its "on" or "release" position, gas within the cylinder is allowed to flow freely by the valve means 38 so that the stiffness of the piston 28 in the cylinder 26 disappears. The backrest can then be moved up or down very easily.

Ther are, however, circumstances in which the backrest may need to be moved quickly from an inclined position to a horizontal position without a nurse or doctor having to look for the release lever 40. For example, a nurse or doctor may suddenly see that the patient is having a heart-attack, in which case they must be able to force the backrest down quickly without operating the lever 40. To permit this, the holding means 20 has provision for the build-up of gas pressure in the cylinder 26 to be released as the backrest is forced downwards. This can be effected, for example, by a pressure-release valve in the piston 28 or in some other part of the holding means 20.

Gas struts are freely available on the mar ket, and their precise construction varies ac cording to the manufacturer. In general, any commercial gas strut which is adapted to operate in the manner described above would be suitable for use in a bed in accordance with the invention.

Claims

1. A hospital bed having a pivotally mounted back-rest which is held in any se lected position of inclination by holding means provided with a release lever positioned so that the lever can easily be operated by a patient in the bed, the said holding means comprising a gas strut in the form of a cylinder and piston containing gas under pressure which is adapted to allow the backrest to be forced down quickly into its horizontal position without actuation of the release lever.

2. A hospital bed according to claim 1, in which the backrest comprises a portion of a mattress platform supported by a frame, the backrest being pivotally mounted on the supporting frame so that it can be swung upwards out of a horizontal position into an inclined position.

3. A hospital bed according to claim 2, in which the gas strut is pivotally connected between a plate or bracket welded or otherwise attached to the lower portion of the backrest and a cross-girder or bracing member on the frame.

4. A hospital bed according to claim 3, in which the piston of the gas strut is provided with a piston rod which is pivotally connected to a nose portion of the plate or bracket.

5. A hospital bed according to claim 4, in which the end of the cylinder of the gas strut remote from the piston rod carries a resilient buffer and valve means which are under the control of the release lever.

6. A hospital bed according to claim 5, in which the valve means form an extension of the cylinder of the gas strut and are pivotally mounted on a bracket or lug welded or otherwise secured to the cross-girder on the frame.

7. A hospital bed according to claim 5 or claim 6, in which the internal construction of the cylinder of the gas strut and the construction of the valve means are such that the piston is stiff within the cylinder, due to gas pressure within the latter, when the release lever is in its "off" or "non-release" position, while, when the lever is moved into its "on" or "release" position, gas within the cylinder is allowed to flow freely by the valve means so that the stiffness of the piston in the cylinder disappears.

8. A hospital bed according to any preceding claim, in which, to permit the backrest to be forced down quickly without operating the release lever, the build-up of gas pressure in the cylinder of the gas strut is releasable, as the backrest is forced downwards, by a pressure-release valve in the piston of the gas strut or in some other part of the holding means.

9. A hospital bed substantially as described herein with reference to the accompanying drawing.