GB2078176A - Wheeled chair or platform - Google Patents

Abstract

A wheeled chair or wheeled goods platform particularly a wheel chair as shown comprising a seat 10, 11 mounted on an upper element 14 of a parallelogram linkage 14, 15, 16, 17 wheels 12, 13 being attached to a lower element of the linkage and a lever or other means 20 being provided to raise and lower the seat relatively to the wheels through the parallelogram linkage whereby downward and rearward movement of the seat or platform is accompanied by rearward movement in relation to the wheels. By this means an occupant can be lowered onto a chair or other support without the necessity for leaving the seat of the wheel chair. The chair may comprise a turntable engageable with a cover attached to a vehicle seat. The rear element 16 of the linkage is re-entrant. <IMAGE>

Description

SPECIFICATION Wheeled chair or platform This invention relates principally to wheel chairs for the disabled but it is also applicable for transportation of goods by means of a wheeled plafform, wherein the platform for the goods takes the place of the seat on a wheel chair.

For wheel chairs users, the problems of transfer from the wheel chair seat to a normal chair or seat can be very severe. It is often impossible for a disabled person to make the transfer without the assistance of another person. Such transfer often involves physically lifting the disabled person out of the wheel chair and onto the other chair or seat.

Such lifting is both arduous for those assisting the disabled person and can often be painful and injurious to the disabled person. Problems of transfer are particularly severe for example in moving a disabled person from a wheel chair into a car, train or aircraft seat. Passenger cars have access limited by such factors as door height and width and the position of the car seat in relation to such door opening.

Where disabled persons are transferred onto a car or aircraft seat it is usual to arrange for the wheel chair to be collapsible so that it can be stowed in another part of the vehicle during the subsequent journey so that it is ready for use again at the destination.

It has been proposed to transfer a wheel chair directly into a motor vehicle by means of a suitably designed mechanism. In such a case the wheel chair is partially collapsed so that it can enter the vehicle while the disabled person is occupying the seat of the wheel chair. The chair occupies the position of the normal vehicle seat and to this extent the vehicle has to be specially adapted.

Such adaptation and the associated mechanism is relatively expensive although it is possible to remove the mechanism and to replace the normal seat in the car and to this extent the arrangement is preferable to the specially designed invalid cars which have been available for some time.

It is however often desired that a disabled person should travel in a normal car which is either unmodified or only modified to a small extent.

It is the object of this invention to provide a wheel chair or platform which enables transfer of a disabled person or of goods particularly though not exclusively into a vehicle the arrangement being inexpensive and involving minimum modification of associated equipment.

According to the invention there is provided a wheel chair or platform comprising a seat or platform mounted on an upper element of a parallelogram linkage, wheels being attached to a lower element of such linkage, means being provided for lowering and raising the seat or platform in relation to the wheels, through the parallelogram linkage, whereby downward movement of the seat or platform is accompanied by rearward movement thereof in relation to the wheels, the arrangement being such that an occupant of the seat or goods on the platform can be lowered and at the same time displaced rearwardly onto a support onto which the weight is thus transferred.

This is principally applicable to a wheel chair and is particularly useful for transferring an occupant of a wheel chair into a passenger car or into an aircraft seat where access is restricted. It will be apparent there the occupant is transferred without the necessity to leave the seat of the wheel chair itself.

In accordance with a further aspect, the invention resides in a procedure for transferring an occupant of a wheel chair, of the kind referred to herein, onto a support, comprising lowering the seat on the wheel chair, so that downward and rearward movement towards the support takes place by means of the parallelogram linkage.

The invention will now be described by way of example with reference to the accompanying drawings in which; Fig. 1 is a side elevation view of a wheel chair constructed in accordance with the invention and showing positions which it can occupy, Fig. 2 shows a passenger car into which an occupant of a wheel chair can transfer and, Figs. 3, 4 and 5 show successive stages in such entry into the vehicle.

Referring to Fig. 1 this shows a wheel chair of relatively simple construction and therefore relatively inexpensive to produce. The chair has a seat comprising a seat portion 10 and backrest portion 11 and is mounted on two larger rear wheels 12 and two smaller castor type front wheels 13. The seat 10, 11 is mounted on a horizontal element indicated generally at 14 of the parallelogram linkage including front bars 1 5 and rear bars 1 6. The wheels are similarly mounted on a lower element 1 7 of the parallelogram linkage.

In its construction the chair preferably comprises two side by side parallelogram linkages each including upper, lower and connecting elements.

However it may be convenient for the rear upper hinge of the parallelogram linkage that is between the element 14 and the bar 16 to be towards the centre of the width of the seat for reasons that will be explained.

As shown the rear larger wheels 1 2 are pivoted at the hinge point at the bottom rearward corner of the parallelogram linkage but there is no necessity for the wheels to be pivoted at this point and they may be on downward rearward of forward extensions of the lower element 1 7 of the linkage. The front castor wheels 1 3 are provided at the lower ends of the upright front bars 1 5 so that as the parallelogram linkage collapses the castor wheels 13 move fowardly relatively to the front bottom hinge of the linkage.

There is a connecting rod 18 which in this example is coincident with the axis of the hinge at the front lower corner of the parallelogram linkage and to this rod is pivotally mounted a foot rest 1 9.

Attached at the upper rear corner of the linkage is a handle 20. In the normal upright position of the wheel chair as shown in full lines in Fig. 1 this handle 20 lies in a plane parallel with the upper element 14 of the linkage and is retained in place by a fixture 21 on such upper element 14. The outer end of the handle is convenient for the operator. The handle 20 is none rotatably connected to the rear bar 1 6 of the parallelogram linkage so that if the handle 20 is lifted the linkage operates in the manner illustrated in dotted lines in Fig. 1 to both lower the seat and move it in a rearward direction relatively to the wheels. The rear bar 16 of the parallelogram linkage is of re entrant configuration so that its centre part is substantially forward of the top and bottom rear hinges of the linkage.As shown in dotted lines when the seat has reached its lowermost position the handle 20 is in an upright position generally coplanar with the backrest portion 11 and the rear bars 1 6 are in the position of arm rests for the occupant. The handle 20 may have a release mechanism enabling it to be returned to the horizontal position beside the seat portion 10 of the seat when the seat is in its lower position.

In an alternative construction the handle is connected to a ratchet mechanism whereby the seat is lowered incrementally by upward and downward movement of the lever 20.

Over the rear wheel 12 shown there is a brake 22 which is shown in full lines in its released position. It is connected to the rear bar 1 6 of the parallelogram linkage and may be connected to a lever (not shown) adjacent to the handle 20 so that the brake may be manually operated to lock the rear wheel when the downward and rearward operation is commenced. Cable operation wherein the cable passes through the rear bar 1 6 is a convenient arrangement. The brake may alternatively be automatically operable to lock the rear wheels 12 when the downward and rearward movement commences.

The wheel chair as shown in Fig. 1 is suitable for use for transferring an occupant onto a passenger car or aircraft or train seat. Figs. 2 to 5 show successive stages in the transfer into a passenger car indicated generally as 23. Such a car has normal seat 24 which in this case is shown behind the normal steering wheel and controls 25 of the vehicle. The invention is however equally applicable to entry at the front passenger side of the car. The seat 24 is preferably mounted on runner enabling forward and rearward adjustment to take place and in many cars it is desirable that the rearward movement shall be greater than that which is usually provided in the standard car.Modification to enable such additional rearward movement to take place is however quite small and can normally be carried out in such manner as to enable the car to be returned to standard condition at a later stage for example when the vehicle is to be sold.

The car door opening is bounded at its lower edge by a sill which is lower than the surface of the car seat 24.

As illustrated the car seat is fitted with a cover 27 which engages over the seat portion of the car seat. This cover is preferably made from a material which will not damage the upholstery of the car seat but which has some rigidity at least in its centre section. Since the normal car seat would usually have a slight rearward slope the cover 27 may be reinforced to bring its centre portion to a near horizontal position.

Fig. 2 shows also the wheel chair of the kind described in relation to Fig. 1 in addition to the features described the seat portion 10 has beneath it a turntable 28. A slot 29 is provided in the cover 27 on the car seat and together the turntable 28 and slot 29 form a register which serves to guide the wheel chair seat into the proper position as will be described. The slot 29 has one open end directed outwardly of the car door opening and around its closed end corresponding in radius to the external sides of the turntable 28 on the wheel chair seat.

Fig. 6 shows the next stage in transferring the wheel chair occupant. The wheel chair is placed so that its rear is towards the car door opening and it is moved backwards until the rear wheels 12 come into contact with the sill 26 on the vehicle or alternatively when the rear bars 1 6 contact such sill. The first contact will depend to some extent on the height of the ground in relation to the car seat. It can be seen that in the example shown the wheel chair is being loaded from a curb and in this case it will usually occur that the rear wheels 12 encounter the sill first. However where the wheel chair is on the same level as the vehicle wheels the wheel chair wheels may pass under the sill to some extent.

The lever 20 is now raised resulting in downward and rearward movement of the seat of the wheel chair relatively to its wheels. The brake should at this time be applied to prevent the wheels of the wheel chair moving away from the side of the car. The turntable 28 beneath the seat portion 10 of the wheel chair seat should register in the slot 29 in the cover 27 on the car seat.

Sliding movement will occur as the seat of the wheel chair moves in a rearward direction towards the centre of the car seat.

As shown in Fig. 4 as the weight of the seat and occupant are transferred onto the car seat continued lifting of the lever 20 will result in raising of the wheels 12 and 13 from the ground while these are still outside the sill 26 of the car.

As soon as it is possible the seat of the wheel chair will be moved fully into register with the slot 29 that is in a position in which the turntable 28 is at the rounded closed end of the slot 29.

The parallelogram linkage is substantially completely collapsed by moving the lever 20 to its fully rearward and upward position or alternatively by operating the ratchet to its maximum extent.

This will then bring the wheels above the sill 26 so that the entire wheel chair can be swivelled about the centre of the turntable 28 into the position illustrated in Fig. 5. It may be necessary to provide rounded corners on the rear edges of the seat portion of the wheel chair seat to enable the seat of the wheel chair to swivel. It is for this reason that it may be convenient for the rearward upper hinge of the parallelogram linkage to be near the centre of the back of the seat of the wheel chair.

In order that the front wheels 13 and footrest 1 9 can clear the door opening front edge is is often necessary for the car seat 24 to be moved to its rearmost position as indicated in Fig. 5.

Preferably this fully rearward position is obtained before the transfer operation is started but the shape and dimensions of the car door opening will dictate the procedure to be followed.

As shown in Fig. 5 the seat of the wheel chair has taken up a position on the car seat 24 and the front wheels 13 and footrest 1 9 of the wheel chair are in the foot well of the car. In this position the parallelogram linkage can take up an over centre position that is one in which the front upper corner hinge is below the rear lower corner hinge and this allowed the footrest 1 9 to sink down to the floor of the vehicle so that the occupant need no longer use the footrest but can use the normal footwell in the car.

A normal seat belt can be used by the occupant as if he were occupying the car seat in the ordinary way.

To bring the wheel chair with the occupant out of the car it is first necessary to bring the parallelogram linkage back from the over position.

Convenient a further lever (not shown) may be provided to enable this to be carried out.

When the wheels 12, 13 are again above the level of the sill 26 it is possible for the wheel chair to be rotated about the axis of the turntable 28.

With a combination of rotation and sliding movements the wheel chair is brought to a position in which the wheels 1 2 and 13 are resting on the kerb or on the roadway beside the vehicle. By means of the lever 20 the seat is raised into the fully upright position and locked to enable the wheel chair to be used to move the occupant from place to place. By removing the cover 27 it is possible for the vehicle to be used by a none disabled passenger. The additional rearward movement of the seat 24 in the car furthermore is preferably not sufficient to limit unduly the leg room available for back seat passengers in the car.

When the wheel chair is not in use it can be folded substantially flat and for this purpose the backrest portion preferably folds onto the seat portion 10. Some form of lock is required to retain in selected position.

Conveniently the seat of the wheel chair may be made as plastics moulding either in one piece or in two and therefore has minimum thickness particularly in the seat portion thereof. This ensures that the occupant is not significantly higher in the vehicle than would be the case if he were occuplying the normal car seat.

Transfer into and out of the vehicle will in most cases require external assistance but such assistance does not involve lifting the wheel chair occupant bodily and is merely for the purpose of guiding the seat into the correct position on the cover 27 on the car seat and for assisting in the swivelling movement of the chair as well as in acutation of the forward and rearward sliding movement of the car seat within the vehicle.

When used on aircraft or train seats or on seats in the home the swivelling facility may not be necessary.

Instead it will be possible for the occupant simply to move rearwardly and downwardly onto a chair placed immediately behind the wheel chair. For aircraft use the wheel chair may be light in weight and would be dimensioned so as easily to travel along the alleyway between the sets of aircraft seats. By this means it is often possible for the occupant of a wheel chair to use a normal aircraft seat which is not specially modified to take disabled persons.

The parallelogram linkage can be used also for a platform instead of as a wheel chair. In place of the seat there is a simple platform attached to the upper element of the parallelogram linkage. Goods may be carried on this and can be transferred to a lower or upper and laterally displaced position as required. For example the apparatus may be used as a trolley onto which goods may be loaded when the platform is in its upper position. It is then rolled on its wheels to a different location at which the goods are transferred to a lower level by downward and rearward movement of the platform relatively to the wheels.

Claims (15)

1. A wheeled chair or platform comprising a seat or platform mounted on an upper element of a parallelogram linkage, wheels being attached to a lower element of such linkage, means being provided for lowering and raising the seat or platform in relation to the wheels, through the parallelogram linkage, whereby downward movement of the seat or platform is accompanied by rearward movement thereof in relation to the wheels, the arrangement being such that an occupant of the seat or goods on the platform can be lowered and at the same time displaced rearwardly onto a support onto which the weights is thus transferred.

2. A wheeled chair or platform as claimed in claim 1 wherein the rear element of the parallelogram linkage is of re-entrant form to provide clearance relatively to the support onto which the seat or platform is to be transferred.

3. A wheeled chair or platform as claimed in claim 1 or claim 2 wherein the means for lowering and raising the seat or platform includes a lever for collapsing or erecting the parallelogram linkage.

4. A wheeled chair or platform as claimed in claim 3 wherein the means for lowering and raising the seat of platform includes a ratchet mechanism actuated by said lever.

5. A wheeled chair or platform as claimed in any one of the preceding claims wherein a brake is arranged to act on at least one of the wheels.

6. A wheeled chair or platform as claimed in claim 5 wherein the brake is automatically operable when the lowering of the seat or platform commences.

7. A wheeled chair or platform as claimed in claim 5 wherein the brake is manually operable.

8. A wheel chair as claimed in any one of the preceding claims wherein the seat has means for registration on a support onto which it is to be transferred, such registration means enabling the seat to be rotated relatively to said support about a substantially vertical axis.

9. A wheel chair as claimed in claim 8 wherein the means for registration is a turn table arranged to register in a complementary formation on the support.

10. A wheel chair as claimed in claim 9 wherein, where the support is a seat, the complementary formation is provided in a cover for the seat.

11. A wheel chair as claimed in claim 10 wherein said complementary formation includes means for permitting guided lateral movement of the seat relatively to the axis about which it is rotatable.

12. A procedure for transferring an occupant of a wheel chair, as claimed in any one of the preceding claims, onto a support, comprising lowering the seat one the wheel chair, so that downward and rearward movement towards the support takes place by means of the parallelogram linkage.

13. A procedure as claimed in claim 12 wherein the support is a vehicle seat in a vehicle, comprising placing a cover on the seat and then lowering the seat of the wheel chair on the covered vehicle seat from one side thereof, raising the wheels from the floor and then swivelling the seat to a position in which the occupant is sitting, in the wheel chair seat, in the vehicle seat in a forward posture.

14. A procedure as claimed in claim 13 wherein the cover for the vehicle seat includes a register for the seat of the wheel chair permitting relative rotation.

15. A procedure as claimed in claim 14 wherein relative sliding movement between the wheel chair seat and the cover is necessary to bring the seat of the wheel chair into a position in which it can rotate to enable the occupant to take up the required position relatively to the vehicle seat.

1 6. A procedure as claimed in any one of claims 13 to 1 5 wherein movement of the vehicle seat in a rearward direction takes place before lowering the seat of the wheel chair onto it.

1 7. A wheeled chair or platform substantially as hereinbefore described with reference to and as shown in the accompanying drawings.

1 8. A procedure for transferring an occupant of a wheel chair substantially as hereinbefore described with reference to and as shown in the accompanying drawings.