GB2192533A

GB2192533A - Improvements to bed immobilisers

Info

Publication number: GB2192533A
Application number: GB08617487A
Authority: GB
Inventors: Ian Doherty
Original assignee: Edward Doherty & Sons Ltd
Current assignee: Edward Doherty & Sons Ltd
Priority date: 1986-07-17
Filing date: 1986-07-17
Publication date: 1988-01-20
Also published as: GB8617487D0

Abstract

A hospital bed immobiliser wherein a comparatively small initial movement of a pedal (2) forming part of it from its rest position (A) to an intermediate position (B) causes a comparatively large movement of one or more bed-immobilising pads (3) from a retracted position (A') to an intermediate position (B') immediately above the floor, while continued movement of the pedal (2) from the intermediate position (B) over a comparatively large distance to a final position (C) gives rise to a comparatively small displacement of the pad or pads (3) from the intermediate position (B') to a final position (C') where the pad or each pad engages the floor. A good mechanical advantage is therefore gained in applying pressure to the pad or each pad (3) as it comes into contact with the floor. <IMAGE>

Description

SPECIFICATION Improvements to bed immobilisers This invention relates to bed immobilisers.

It is usual to provide hospital beds with immobilising means so as to stop movement of the bed with respect to the floor supporting it. Such bed immobilisers frequently comprise friction pads which can be retracted out of contact with the floor when it is desired to move the bed but which can be forced down into contact with the floor to immobilise the bed. Movement of the friction pads is generally carried out by depressing a pedal mounted on the bed frame.

The aim of the present invention is to improve the mechanical advantage between the pedal and the friction pads so as to apply increased pressure to the pads as they come into contact with the floor on being moved down from their retracted position. With this aim in view, the present invention is directed to a bed immobiliser wherein an initial comparatively small movement of the pedal out of its normal rest position causes a comparatively large movement of the or each friction pad out of its retracted position to a position close to the floor, while further movement of the pedal over a comparatively large distance to its final position produces a comparatively small movement of the or each friction pad from its position just above the floor to actual contact with the latter.

By these means, a good mechanical advantage is gained in applying pressure to the friction pad(s) over the last part of their movement when it is desired to immobilise the bed.

An example of a hospital bed incorporating a bed immobiliser in accordance with the invention is shown in the accompanying drawing which shows a small part of the bed in side elevation.

The hospital bed shown partially in the drawing comprises a frame 1 forming part of the bed chassis, an immobilising pedal or other lever 2 pivotally mounted at 2a on the bed frame 1, an immobilising friction pad or foot 3 arranged for vertical movement on the bed frame and depending therefrom, and a castor or wheel 4 for supporting the frame 1 at one of its corners. It will be understand that four castors or wheels 4 will be provided-one at each corner of the rectangular frame 1-and that there will be anything between one and four immobilising friction pads or feet, all controlled (if there are more than one) by the pedal 2.

As is usual in hospital beds of the general construction outlined above, depression of the pedal 2 causes the friction pad or pads 3 to be lowered into contact with the floor. When the pad is in its retracted position A', it lies well clear of the floor so as to avoid obstacles on the latter. It thus follows that the pad has to be moved a substantial distance out of its retracted position A' into the position C' where it is in contact with the floor.

The present invention is based on the premise that no effort on the part of the operator of the pedal is required to move the pad from the fully retracted position A' to an intermediate position B' where it lies just clear of the floor. On the other hand, more effort is needed as the pad is moved from the position B' into the position C' where it engages the floor.

Notwithstanding this fact, bed immobilisers used hitherto are so constructed that the act of depressing the pedal 2 from its rest position A to its final position C is directly proportional to the movement of the pad from its position A' to its position C'.

In contrast to this, the present invention makes provision for a comparatively small initial movement of the pedal 2 from its rest position A to an intermediate position B to cause a comparatively large movement of the pad 3 from its retracted position A' to its intermediate position B' immediately above the floor. Continued movement of the pedal 2 from the intermediate position B over a comparatively large distance to the final position C gives rise to a comparatively small displacement of the pad 3 from its position B' to its final position C' where it engages the floor.

In short, a small movement of the pedal 2 from A to B gives a large displacement of the pad 3 from A' to B', while a large movement of the pedal 2 from B to C results in a small movement of the pad 3 from B' to C'. A good mechanical advantage is therefore gained in applying pressure to the friction pad 3 as it comes into contact with the floor.

The connection 5 between the pedal 2 and the pad 3 (or each pad where there is more than one) can take various forms. It may for example comprise a mechanical linkage to give the desired differential mechanical advantage indicated above, or use could be made of hydraulic or even pneumatic means to provide the necessary operating link between the pedal and the pad.

1. A bed immobiliser for installation in or on a hospital bed, the bed immobiliser having one or more friction pads which are connected to operating means such as a pedal so that the pad(s) can be retracted out of contact with the floor when it is desired to move the bed but can be forced down into contact with the floor to immobilise the bed, in which the connection between the pad(s) and the operating means is so arranged as to apply increased pressure to the pad(s) as the latter come(s) close to and into contact with the floor on being moved down from the retracted position.

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

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Improvements to bed immobilisers This invention relates to bed immobilisers. It is usual to provide hospital beds with immobilising means so as to stop movement of the bed with respect to the floor supporting it. Such bed immobilisers frequently comprise friction pads which can be retracted out of contact with the floor when it is desired to move the bed but which can be forced down into contact with the floor to immobilise the bed. Movement of the friction pads is generally carried out by depressing a pedal mounted on the bed frame. The aim of the present invention is to improve the mechanical advantage between the pedal and the friction pads so as to apply increased pressure to the pads as they come into contact with the floor on being moved down from their retracted position. With this aim in view, the present invention is directed to a bed immobiliser wherein an initial comparatively small movement of the pedal out of its normal rest position causes a comparatively large movement of the or each friction pad out of its retracted position to a position close to the floor, while further movement of the pedal over a comparatively large distance to its final position produces a comparatively small movement of the or each friction pad from its position just above the floor to actual contact with the latter. By these means, a good mechanical advantage is gained in applying pressure to the friction pad(s) over the last part of their movement when it is desired to immobilise the bed. An example of a hospital bed incorporating a bed immobiliser in accordance with the invention is shown in the accompanying drawing which shows a small part of the bed in side elevation. The hospital bed shown partially in the drawing comprises a frame 1 forming part of the bed chassis, an immobilising pedal or other lever 2 pivotally mounted at 2a on the bed frame 1, an immobilising friction pad or foot 3 arranged for vertical movement on the bed frame and depending therefrom, and a castor or wheel 4 for supporting the frame 1 at one of its corners. It will be understand that four castors or wheels 4 will be provided-one at each corner of the rectangular frame 1-and that there will be anything between one and four immobilising friction pads or feet, all controlled (if there are more than one) by the pedal 2. As is usual in hospital beds of the general construction outlined above, depression of the pedal 2 causes the friction pad or pads 3 to be lowered into contact with the floor. When the pad is in its retracted position A', it lies well clear of the floor so as to avoid obstacles on the latter. It thus follows that the pad has to be moved a substantial distance out of its retracted position A' into the position C' where it is in contact with the floor. The present invention is based on the premise that no effort on the part of the operator of the pedal is required to move the pad from the fully retracted position A' to an intermediate position B' where it lies just clear of the floor. On the other hand, more effort is needed as the pad is moved from the position B' into the position C' where it engages the floor. Notwithstanding this fact, bed immobilisers used hitherto are so constructed that the act of depressing the pedal 2 from its rest position A to its final position C is directly proportional to the movement of the pad from its position A' to its position C'. In contrast to this, the present invention makes provision for a comparatively small initial movement of the pedal 2 from its rest position A to an intermediate position B to cause a comparatively large movement of the pad 3 from its retracted position A' to its intermediate position B' immediately above the floor. Continued movement of the pedal 2 from the intermediate position B over a comparatively large distance to the final position C gives rise to a comparatively small displacement of the pad 3 from its position B' to its final position C' where it engages the floor. In short, a small movement of the pedal 2 from A to B gives a large displacement of the pad 3 from A' to B', while a large movement of the pedal 2 from B to C results in a small movement of the pad 3 from B' to C'. A good mechanical advantage is therefore gained in applying pressure to the friction pad 3 as it comes into contact with the floor. The connection 5 between the pedal 2 and the pad 3 (or each pad where there is more than one) can take various forms. It may for example comprise a mechanical linkage to give the desired differential mechanical advantage indicated above, or use could be made of hydraulic or even pneumatic means to provide the necessary operating link between the pedal and the pad. CLAIMS

2. A bed immobiliser according to claim 1, in which the connection between the pad(s) and the operating means is so arranged that an initial comparatively small movement of the operating means out of their normal rest position causes a comparatively large movement of the or each friction pad out of its retracted position to a position close to the floor, while further movement of the pedal over a comparatively large distance to its final position produces a comparatively small movement of the or each friction pad from its position just above the floor to actual contact with the latter.

3. A bed immobiliser according to claim 1 or claim 2, in which the operating means comprise a pedal or other lever pivotally mounted on the bed frame.

4. A bed immobiliser according to any one of claims- 1 to 3, in which the connection between the operating means and the pad(s) comprises a mechanical linkage to give the desired differential mechanical avantage, or an hydraulic or pneumatic linkage.

5. A bed immobiliser substantially as described herein with reference to the accompanying drawing.

6. A hospital bed incorporating a bed immobiliser as claimed in any preceding claim.