GB2281094A - Restraints for wheeled appliances - Google Patents

Abstract

A stretcher trolley (2) has upright fingers (4) spaced lengthwise of the trolley and low down on the side which is to be against the wall of a vehicle. This wall is equipped with a guide and locator (6) and a catch (7) with which the fingers (4) cooperate. The trolley (2) is steered towards the wall at a shallow angle and the leading finger (4) enters the wide mouth of the locator (6) and is guided to a blind end (14). That finger (4) then acts as a pivot as the rear of the trolley (2) is swung towards the wall. The other finger (4) engages and is trapped by the catch (7) and the trolley is secure. The catch (7) may have a remote release device. <IMAGE>

Description

ImDrovements relating to Restraints for Wheeled ApPliances This invention relates to restraints for wheeled appliances such as trolleys for stretchers and is intended primarily for installation in vehicles.

Any wheeled appliance loaded into a van or other vehicle has to be firmly held while the vehicle is in motion. This is particularly true for ambulances adapted to convey stretchers on wheeled trolleys.

Any restraint must not interfere with the free movement of the appliance into and out of the vehicle, which means that there can be problems if it is floor mounted.

Generally, it would be better to leave the floor clear and to have some fitting on the side wall to which the appliance could be attached. But this too is not always straightforward. Once the appliance is in position, up against the wall, a fixture on that wall for holding it may be out of reach or accessible only with difficulty. It is the aim of this invention to provide at least a partial answer to this.

According to the present invention there is provided a restraint for wheeled appliances such as trolleys for stretchers having at horizontally spaced positions on at least one side thereof two fingers at least one of which is upright, the restraint comprising a guide and locator for the first, upright finger and a catch for the second finger, wherein the wheeled appliance to be restrained is steered so that the first finger enters the guide and is located and then arrested thereby, and the wheeled appliance is then swung, pivoting about the located first finger, until the second finger engages and is trapped by the catch.

For convenience, reference will now be made just to trolleys for stretchers, but it will be understood that the principles can be applied to other mobile devices whose wheel arrangements permit the necessary movements.

The fingers may be fittings added to the basic structure of the trolley, or parts of the trolley may already provide suitable members, such as portions of a frame. Preferably, the fingers will be of circular section and they may be a metal tube or rod protected by a resilient sleeve to give a softer engagement by the restraint.

The guide and locator may comprise a simple bracket with a blind end slot open to face the advancing trolley. This slot will preferably have a V-shaped mouth so that the first finger has an easy entry but is then steered towards the blind end. There the slot is preferably rounded and the arc may be just more than 1800 so that there is a slight neck between the mouth and the rounded portion in which the finger locates. With the resilient sleeve this can provide for snap engagement and positive location.

The catch conveniently has a U-shaped body open to the second finger as the trolley is swung towards it. As that finger moves towards the bottom of the U it hits part of a spring-biased, pivoted keep which swings round sufficiently for another part to engage partially, at least, behind the finger. Then a spring-loaded locating pin engages to hold the pivoted keep in place, and thereby the second finger.

This locating pin can be withdrawable from a position remote from the catch, which may be low down on a wall underneath the stretcher. Ambulance staff will not want to grovel underneath to release it. In one embodiment, therefore, the locating pin is the lower end of a vertical rod with a handle at the top. Although this will be against the wall, provided the handle is above stretcher level it should be easy enough to reach over and pull it up to release the catch. Once pulled up, the spring bias will urge the keep back to its initial position and free the trolley, which can then be swung clear and pulled back from the guide and locator.

Instead of a rigid release mechanism such as this rod, there could be a cable led to almost any convenient point clear of the parked trolley.

To cater for different appliances, the guide and locator and the catch will preferably be adjustable in position. In one preferred form they will be mounted on a horizontal track and fixable at selected points along that track.

The leading finger 4 must be upright to act as a pivot for the trolley swinging horizontally. The trailing finger need not be vertical, but it will be preferable to have it so, since then the trolley can be entered in either direction and locked in place, assuming there are similar locating and catch arrangements on both sides of the vehicle. Conveniently, the guide and locator and the catch will be invertible so that they are usable on either side of a vehicle.

For a better understanding of the invention one embodiment will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a perspective view of a stretcher on a trolley, Figure 2 is a plan view of a guide and locator forming part of a restraint for a trolley, Figure 3 is a plan view of a catch forming another part of the restraint, Figure 4 is a plan view of a keep which forms part of the catch, and Figure 5 is an elevation of a release pin mechanism associated with the catch, In Figure 1 a stretcher 1 is carried by a trolley 2 which runs on four castors 3. Aligned with the vertical shaft about which each castor turns there is a finger 4.

This is of circular section and sheathed in a resilient plastics or rubber sleeve 5. It is by means of these fingers at one side or the other that the stretcher trolley can be held firmly in place.

The restraint is in two parts. There is a guide and locator 6 (Figure 2) and catch 7 (Figure 3) spaced to cooperate with respective fingers 4 on one side of the trolley. To cater for different finger spacings they are conveniently mounted on a common horizontal track 8 fitted to a side wall of a vehicle and along which they can be shifted to be clamped in any desired position. They can be inverted, and so are usable on a similar track on the opposite side of the vehicle.

The guide and locator 6 is basically a horizontally projecting bracket of J-form in plan view, the longer leg 9 being adjacent the track 8 and forming a blind end slot 10 with the shorter leg 11. This slot 10 is contoured rather like a keyhole, with its open end having a divergent mouth 12 and, after a short parallel section which forms a slight neck 13, terminating at the blind end in a rounded portion 14 with an arc exceeding 1800. The slot 10 is open generally towards the catch 7 and its centre line inclines slightly away from the wall on which the locator is mounted.

The catch 7 has a body 15 of sandwich construction, with two outer horizontal plates of similar size and shape and the "filling" being plates within the bounds of the two outer ones and which create a slot for a keep, as described below. In plan view the profile of the body 15 has a U-shaped recess 16 opening away from the wall on which it is mounted. The rounded base of the U is slightly wider and offset to one side with respect to its mouth. The filler plates create a generally L-shaped slot 17 between the outer plates of the body 15 with its convex corner open to the most of said one side of the recess 16 and its rounded base.

Within the slot 17 there is a spring-loaded, pivoted keep 18 with the general shape of a question mark.

At the end of its straight tail 19 there is an aperture 20 and at the middle of its curved portion there is a widening to accommodate an aperture 21 with a counter bore 22, the shoulder formed within it having a small hole 23. The keep 18 is positioned in the slot 17 so that the aperture 21 registers with holes in the outer plates adjacent said one side of the recess 16. A pivot pin 24 through these holes and the keep screws into a member 25 secured to one of the outer plates. Just beside this there is a small hole 26 in the member 25 which receives one end of a coil spring (not shown) housed within the counterbore 22 and surrounding the pivot pin 24, while its other end engages in the hole 23.

The spring imparts a bias to the keep 18 urging it to the position shown in Figure 3, where the knee between the tail 19 and the curved portion projects into the recess 16 and the free end or toe of the curved portion is retracted clear of the recess, or virtually so.

The pivot pin 24 is positioned so that as the keep 18 swings, the aperture 20 comes into registry with aligned apertures 27 in the outer plates of the body 15 near the edge adjacent the wall. Mounted over these apertures there is a guide 28 for the lower end of a rod 29. It contains a spring 30 urging the rod downwards so that, without impediment, its rounded lower tip projects through the upper of the two apertures 27 into the slot 17. The upper end of the rod 3 passes through a guide 31 fixed to the wall and at the top there is a handle 32.

In use, the trolley is manoeuvred so that the leading finger 4 adjacent the wall enters the slot 10. The sleeve 5 is slightly squeezed as it is pushed through to locate in the rounded end 14. There it forms a pivot, and the trolley is swung sideways for the trailing finger on that side to enter the recess 16. It hits the knee of the keep 18 which is thereby swung about the pivot pin 24 to bring the curved portion into the recess 16 partially behind the finger 4. At the same time, the tail 19 swings round, wedging up the rod 29 by its lower tip until the aperture 20 comes directly below the rod 29, which then snaps down into it. The keep 18 is therefore locked and so is the trolley with its stretcher.

To release, the handle 32 is pulled up, and the trolley is swung away and then pulled backwards. The keep 18 automatically reverts to the open position by virtue of the spring surrounding the pivot pin.

Claims (15)

1. A restraint for wheeled appliances such as trolleys for stretchers having at horizontally spaced positions on at least one side thereof two fingers at least one of which is upright, the restraint comprising a guide and locator for the first, upright finger and a catch for the second finger, wherein the wheeled appliance to be restrained is steered so that the first finger enters the guide and is located and then arrested thereby, and the wheeled appliance is then swung, pivoting about the located first finger, until the second finger engages and is trapped by the catch.

2. A restraint as claimed in Claim 1, wherein the fingers are fittings added to the basic structure of the trolley.

3. A restraint as claimed in Claim 1, wherein parts of the trolley provide suitable members, such as portions of a frame, to act as the fingers.

4. A restraint as claimed in Claims 1, 2 or 3, wherein the fingers are of circular section.

5. A restraint as claimed in Claim 4, wherein each finger is a metal tube or rod protected by a resilient sleeve to give a softer engagement by the restraint.

6. A restraint as claimed in any preceding claim, wherein the guide and locator comprises a bracket with a blind end slot open to face the advancing trolley.

7. A restraint as claimed in Claim 6, wherein the slot has a V-shaped mouth so that the first finger has an easy entry but is then steered towards the apex.

8. A restraint as claimed in Claim 6 or 7, wherein the blind end of the slot is rounded, and the arc is more than 1800 so that there is a neck between the mouth and the rounded portion in which the finger locates.

9. A restraint as claimed in any preceding claim, wherein the catch has a U-shaped body open to the second finger as the trolley is swung towards it, a spring-biased, pivoted keep which swings round sufficiently to engage partially, at least, behind the finger as that finger moves towards the bottom of the U after hitting part of the keep, and a spring-loaded locating pin which engages to hold the pivoted keep in place, and thereby the second finger.

10. A restraint as claimed in Claim 9, wherein the locating pin is withdrawable from a position remote from the catch.

11. A restraint as claimed in Claim 10, wherein the locating pin is the lower end of a vertical rod with a handle at the top.

12. A restraint as claimed in Claim 10, wherein the locating pin is releasable via a wire cable led to a point remote from the catch.

13. A restraint as claimed in any preceding claim, wherein the guide and locator and the catch are adjustable in position.

14. A restraint as claimed in Claim 13, wherein the guide and locator and the catch are mounted on a horizontal track and fixable at selected points along that track.

15. A restraint for wheeled appliances substantially as hereinbefore described with reference to the accompanying drawings.