GB2036670A - Invalid carriage - Google Patents

Abstract

A self-propelled invalid carriage comprises a three-wheeler chassis with two steerable front wheels 1 and a non-steerable rear driving wheel 3, making for good weight distribution with the occupant's seat 56 mounted above the driving wheel, particularly if electric propulsion batteries 20 are mounted in front of the steering wheels. The seat 56 is displaceable in the longitudinal direction of the vehicle and may also be rotatable to facilitate mounting and dismounting by disabled persons. As shown the seat 56 is constituted by a manually movable wheel chair which can be hauled up lowerable ramps 61 by a screw-threaded spindle driven by an electric motor 70. Also described are arrangements for steering, braking etc., for positional adjustment of foot rests, and for removing the front end provided for outdoor travel and replacing it by one more convenient for indoor use. <IMAGE>

Description

SPECIFICATION Invalid carriage This invention relates to an invalid carriage constructed as a self-propelled vehicle and basically comprising a seat, with back rest, on a three-wheeler chassis with an electrical drive unit.

Known invalid carriages of this kind are all built so that there are two rear wheels, above which a bench seat is situated, and there is a steerable front wheel.

Drive can be applied to the front wheel or to the two back wheels. This arrangement has the advantage that below the seat unit, between the two rear wheels, a great deal of space is available for housing the drive elements including batteries where appropriate, and the steering mechanism can be of very simple design. The disadvantage of the arrangement is that the weight (driver, drive unit and batteries) bears substantially entirely on the rear wheels and therefore it is difficult to travel over obstacles, even small ones. But the serious disadvantage of these invalid carriages is that the physically handicapped person usually can get on to the seat only with the help of one or two assistants, since free access to the seat is blocked by the two rear wheels.In one known arrangement, this drawback is supposed to be remedied by arranging one of the rear wheels to be capable of being swung to the rear to allow the invalid to get in and out. But this aid also can scarcely be operated by a physically handicapped person and allows access only to those persons who can still support themselves at least partially.

The present invention has as its object to provide an invalid carriage of the kind described which (1) makes it possible for even considerably handicapped persons to get in and out on their own, without assistants, (2) can be operated in a simple manner and even by such physically handicapped persons, (3) can travel over relatively small obstacles without injury, (4) is reliable in operation and (5) allows production at a moderate cost.

According to the present invention this is achieved in that the three-wheeler chassis comprises two forwad steerable wheels (these being slewablefor steering) and a rear non-slewable driving wheel and that the seat is mounted above the driving wheel so as to be displaceable in the longitudinal direction of the vehicle and pivotable if necessary and to be capable of being fixed in the particular position desired.

This arrangement of the seat above a well-sprung rear wheel, which is used as the driving wheel at the same time, has the advantage that the seat can always be slid or turned into such a position for getting in and out that a physically handicapped person can seat himself without difficulty. Thus it is even possible to get on to the carriage from behind, with the seat turned through 1800 and displaced rearwardly, which is highly advantageous especially in restricted spaces. It is also possible with this invalid carriage to move side-on to a pay desk or table etc. and, by turning the seat, to sit front-on to the desk or table.

Furthermore, with such a vehicle it is ensured on the one hand that the driver's weight bears on the driving wheel, thus effecting a good grip on the surface over which the carriage is travelling, and on the other hand that the total load can be distributed in the desirable way over all three wheels, and does not simply bear down on the rear wheels. This is the case more expecially if the relatively heavy driving batteries are situated in front of the steerable wheels. A further result is that small obstacles can reliably be travelled over without difficulty, since the individual wheel load is relatively small. This low individual wheel load is also useful for operational safety, since the good wheel load distribution, together with a floating axle, avoids excessively hard shocks on the wheel suspension.

It is true that because of the provision of two front steerable wheels the steering mechanism is more expensive than an arrangement with a single steerable wheel, but it does afford the possibility of transmitting the swinging movement of a steering lever or arm disproportionately strongly to the steerable wheels, thus achieving a very small turning circle for such a vehicle. Of course this further promotes easy operation of this invalid carriage.

Since, because of the uniform weight distribution particularly, such an invalid carriage can be given a relatively light construction, this kind of vehicle can also be produced without too much expense, i.e. at an economic price.

If the invalid carriage is constructed with a chassis comprising tubes which are divided at a bridge supporting the steerable wheels by means of a bridge bar and are connected to one another by coupling sleeves, it becomes possible to interchange the front frame of the invalid carriage according to the present invention. A stable front housing part, suitable for outdoor journeys and supporting the battery housing with the heavy batteries, can then be replaced temporarily with a front housing part which simply has small steerable rollers which can be operated for example by a small servomotor, making the vehicle well-adapted for indoor use.

The vehicle described hereinafter is designed so as to allow physically handicapped people to cope with quite long distances, even if such distances include considerable upward or downward gradients and possibly sections of roadway which are badly consolidated and bumpy. Thus it is possible for a handicapped person to move in a manually movable wheel chair, which is used indoors, to this invalid carriage constructed as a self-propelled vehicle, change conveyances there in a very simple manner, and move about outdoors within relatively wide limits. The seat of the invalid carriage is rotatable, so that the handicapped person can also move up side-on to a table, counter etc. and thus perform activities which normally would be impossible for such a person.

However, because of the fact that the handicapped persons have to leave their manually movable wheel chair at the place where they transfer to the invalid carriage constructed as a self-propelled vehicle, once they arrive at their intended destination they have to have a further wheel chair available or must remain confined to the self-propelled invalid carriage. A further object of the present invention is to obviate this disadvantage, and and according to a feature of the present invention this is made possible in that the seat of the self-propelled invalid carriage is a manually movable wheels chair which can be pushed over the driving wheel and secured in the desired position.

The construction of the three-wheeler chassis with two forward steerable wheels and one rear driving wheel, which is particularly advantageous for versatility in use and for good running properties, also readily allows this pushing-on of a manually movable wheel chair since the rear driving wheels can easily fit between the supporting wheels of a manually movable wheel chair. Thus it simply has to be ensured that the manually movable wheel chair can be pushed in the simplest way over the driving wheel and secured there in such a position that the supporting wheels of the wheel chair are lifted sufficiently clear of the roadway to allow unimpeded travel with the self-propelled carriage.

One way of ensuring this is to arrange that the driving wheel is mounted by means of pivotable struts or spring legs on the three-wheeler chassis and that the struts are adapted to be displaced by means of a shifting device adjustable with an electric motor-mechanical, hydraulic, pneumatic or hydropneumatictype - into an upper limit position and a lower limit position. The displacement of these struts into the lower limit position swings the entire chassis about the axis of the two front steerable wheels and downwards so that the manually movable wheel chair can be run over the chassis or a support provided above the driving wheel. Then by swinging the struts upwardly the chassis is lifted again, at the same time as the manually movable wheel chair situated above it, and the said chair is thus held in this position by this operation.The moving-off of the manually movable wheel chair is effected in the reverse sequence, by moving the struts downwardly into the lower limit position and running-away the manually movable wheel chair. If the pivotability of the struts of the driving wheel is not sufficient to allow the necessary ground clearance for the manually movable wheel chair, a special seat accommodating means can be provided on the support arranged above the driving wheel, said means being formed of pairs of levers adapted to be swung out upwardly by the adjustable shifting device also.A further possible method of taking the manually movable wheel chair over the driving wheel of the self-propelled carriage consists according to a feature of the present invention in that laterally of the driving wheel there are arranged two run-on ramps which are pivotable about pivot pins, the pivot pins being situated behind the centre of gravity of the wheel chair when it has been run on to the three-wheeler chassis. With this construction, the handicapped person in his or her wheel chair moves up the ramps, arrives thus above the driving wheel over the chassis, and is lowered on to this chassis by the tilting of the ramps about their pivot pins. The manually movable wheel chair can then be easily secured in this position.Here again the manually movable wheel chair can be run off in the reverse sequence, the running-off operation being assisted by connecting the ramps to one another by means of a cross-member and arranging between the cross-member and the three-wheeler chassis a securing pneumatic spring which presses the ramps into the ramp negotiating position.

With this arrangement it is also possible to bring the manually movable wheel chair into its operating position for the self-propelled vehicle by means of a servo force, by arranging above the driving wheel a traction device which can latch on to the wheel chair and can be driven by an electric motor. This traction device can itself consist of a screwthreaded spindle, a rope system, or hydraulic elements. It is readily possible by latching the device to secure the manually movable wheel chair in the correct operating position on the self-propelled vehicle and also to allow unimpeded running of the wheel chair from off the vehicle.

The aforesaid ramps may optionally also comprise end rollers and be provided with a spring which presses the ramps towards the readway so that, when the carriage is being used as a self-propelled vehicle as originally, loads can be deposited on these ramps or an assistane can also travel with the invalid, standing on the ramps.

The construction proposed according to the invention for the self-propelled invalid carriage now makes it possible for handicapped persons, without difficulty, to travel with their normal manually movable wheel chair to the self-propelled vehicle, place this familiar wheel chair on the vehicle, and with it travel over relatively considerable distances, even relatively open ground. At the destination this familiar manually movable wheel chair can be set down again without the assistance of other people and there the handicapped person is fully capable of moving about within the framework of his own capabilities.

The invention will now be described, by way of example, with reference to the accompanying diagrammatic drawings wherein: Figure 1 shows a side view, Figure2 a plan view and Figure 3 a front view of an invalid carriage embodying the invention; Figure 4 shows a rear view with the seat pivoted round; Figure 5 shows a side view of the invalid carriage with a driving wheel strut pivoted downwardly; Figure 6 shows the same view with the driving wheel strut pivoted upwardly; Figure 7shows a fragmentary side view with ramps in the run-on position; Figure 8 shows a side view with ramps in the operating position; Figure 9 shows a plan view to the view shown in Figures 7 and 8; and Figure 10 shows a side view with ramps provided with end rollers.

Two steerable wheels 1, 2 and a rigid driving wheel 3 are so arranged on a chassis 4 and the two steerable wheels 1, 2 are situated at the front, in the direction of travel, and the driving wheel is arranged centrally at the rear on the chassis 4. The steerable wheels 1, 2 are secured with their pivot pins 5, 6 on a bridge bar 7 which itself is guided and held through the agency of pressure elements 8 in a bridge member 9. The bridge member 9 is mounted on the chassis 4, which is formed by a total of four tubes situated parallel to one another in the longitudinal direction of the vehicle. The chassis terminates at the front end in a bumper 10 which is carried resiliently in the tubes of the chassis. When the bumper 10 is pushed in, a limit switch 11 is actuated which inhibits forward propulsion of the vehicle.

The driving wheel 3 is connected to the chassis through telescopic springs 12 and a rockable fork 13.

Above this driving wheel 3 there is provided a support 14 which is formed oftubes and on which a vehicle seat 15 with back rest 16 is mounted so as to be rotatable about a central axle 17 and capable of displacement in the longitudinal direction of the vehicle, indicated by the arrows 18. To facilitate climbing in and out, a supporting arm 19 is provided behind the back rest. Within the space bounded by the support 14 and the chassis 4 there is situated an electrical drive unit, which may be supplemented with a internal combustion engine so as to have a composite drive arrangement. The batteries for electric propulsion are situated in a battery housing 20, which is arranged on the chassis 4 in front of the steerable wheels 1, 2.With this arrangement, the wheels 1,2,3 are subjected to approximately uniform loading, although the driving wheel 3 is under slightly greater load so as to achieve a good grip on the ground with this driving wheel.

The two steerable wheels 1,2 are connected to one another by way of a suitable steering mechanism which may be of a kind known perse. This steering mechanism is operated by a bowed steering arm 21, on which the operating elements for control of the vehicle are also arranged. The steering arm 21 is pressed by spring force against a safety arm 23 acting as an end stop, as Figure 1 shows. In this way the bowed steering arm can be used at the same time as a support in the event of frontal impact of the vehicle against something. In operation, the bowed steering arm 21 is swung downwards (arrow 24) for comfortable handling. Pressing the bowed steering arm 21 in the direction of the arrow 24 to its limit position, presses the said arm against a slide pressure plate 25, which is connected to a vehicle brake.Thus, by simply pressing-down the bowed steering arm 21, the vehicle brakes are operated and the vehicle braked. Laterally of the driving wheel 3, on the bearing bracket 14, there are arranged outwardly pivotable foot rests 26, 27 which are required for example if a physically handicapped person wishes to sit at a table 31 after pivoting the seat 15 sideways (Figure 4). It is also possible to provide foot or leg rests 28, likewise outwardly pivotable, above the steerable wheels (Figure 3).

Struts 51 are attached pivotably to the rockable fork 13, and slide attheirfree end in a slide rail 52 situated below the support 14. The struts 51 are connected at the end with a screwthreaded spindle 53, which is also used for pivoting pairs of levers 54, 55, which serve as seat accommodating means for a manually movable wheel chair 56 (shown in dotdash lines). The screwthreaded spindle is driven by an electric geared motor (not shown) which is supplied by the battery arranged in the battery housing 20.

In the run-on position, which is illustrated in Figure 5, the chassis 4, or support 14, is pivoted to such an extent, by pivoting the strut 51 into the lower limit position about the axis of the steerable wheels 1, 2, that the wheel chair 56 can travel completely over the support 14. In this position, the lever pairs 54,55 are also completely swung away so that they disappear within the support 14. When the driving motor rotating the screwthreaded spindle 53 has been switched on, the screwthreaded spindle 53 draws the struts 51 into the upper limit position shown in Figure 6, whereby the support 14 is pivoted into the position of use. At the same time the pairs of levers 54, 55 are also pivoted upwardly and thus lift the wheel chair 56 to an extent sufficient to give the necessary ground clearance for the supporting wheels 57 and guide rollers 58 belonging to this wheel chair 56.In this way the wheel chair is in the correct secured position for operation of the selfpropelled vehicle.

The lowering of the manually movable wheel chair 56 is carried out in the reverse sequence, the electric motor being switched on to drive the screwthreaded spindle 53 in the opposite direction; as a result the pairs of levers 54,55 are lowered, so that the wheel chair 56 is no longer held, and then the bracket 14 is pivoted until the supporting wheels 57 and guide rollers 58 stand on the roadway, and the wheel chair 56 can then be made to travel away from the vehicle.

For moving the wheel chair 56 on and also for moving it off the vehicle, the handicapped person can remain on the manually movable wheel chair 56 and travel over the driving wheel 3, or support 14, with his legs open. However, it is also possible to pivot one of the arm rests 59 of the wheel chair 56 to one side so that the handicapped person can place himself on the seat 60 of the wheel chair 56 sideways, have himself shifted into the travelling position, and then turned into the correct travelling position. This turning of the handicapped person's body can be assisted by providing the seat 60 with a rotating plate or turntable.

In the views shown in Figures 7, 8 and 9 the wheel chair 26 is put on to the support 14 of the selfpropelled vehicle by way of run-on ramps 61,62.

These ramps 61,62 are pivotably mounted on pivot pins 63,64, which are so secured on the threewheeler chassis 4 that they are situated behind the centre of gravity of the wheel chair 56 when it has been run on. In order to obtain a uniform pivoting motion, the two ramps 61, 62 are connected to one another by means of a cross-member 65. Acting on this cross-member 65 is a securing pneumatic spring 66 whose energy storage means swings the ramps 61,62 into the run-on position shown in Figure 7. As a result the wheel chair 56 can run on to these ramps 61, 62, the correct run-on position for the wheel chair 56 being ensured by guide rails 67 and a guide rail 68.

The wheel chair 56 can be run on to the ramps 61, 62 by manual force. But in the views shown in Figure 7 to 9 a screwthreaded spindle 69 is provided which is driven by an electric motor 70 and, by means of a latching device 71 provided at the front edge of the wheel chair 56, draws the wheel chair 56 upwards into the position shown in Figure 8. In this pulling-up movement, the centre of gravity of the wheel chair 56 moves beyond the pivot pins 63,64 of the ramps 61,62, so that the ramps 61,62 are swung about these pivot pins 63, 64 into the position of use shown in Figure 8. This pivoting takes place against the action of the pneumatic spring 66, so that the gas in this pneumatic spring 66 is compressed.In this position of use of the wheel chair 56 the securing pneumatic spring 66 is locked, so that the wheel chair is firmly held in this position of use, on then one hand by the limit position of the screwthreaded spindle 69, or latching device 71, and on the other hand by fixing of the ramps 61,62.

Here again, the wheel chair 56 is run off in the reverse sequence. By releasing the pneumatic spring 66 and putting the wheel chair 56 slightly rearwards the ramps 61,62 are swung into the run-on position shown in Figure 7, and the wheel chair 56 slowly taken down the ramps 61, 62 to the ground by rotation of the screwthreaded spindle 69 by means of the electric motor 70.

Finally, Figure 10 shows a modified constructional form of the ramps 61, 62, which in this case are each provided at the end with a roller or small wheel 72. In this way footboards are formed on which luggage can be placed or an assistant can travel.

Figure 10 also shows a lateral holding device 73 for the legs of the handicapped person. Such a holding device is appropriate if the handicapped person can no longer move his or her legs actively, in other words if the legs would slump sideways without the holding device 73. This holding device 73 is telescopically slidable and is shown in one case (full lines) in the position of use and in the other case (broken lines) in the telescoped position.

Claims (27)

1. An invalid carriage constructed as a selfpropelled vehicle, comprising a seat with back rest mounted on a three-wheeler chassis with electric drive unit, characterised in that the three-wheeler chassis comprises two forward steerable wheels (these being slewable for steering) and a rear non-slewable driving wheel, and that the seat is mounted above the driving wheel so as to be displaceable in the longitudinal direction of the vehicle and maybe also pivotable, and to be secureable in the desired position.

2. An invalid carriage according to claim 1, characterised in that the two steerable wheels are connected with one another via a steering mechanism and to the chassis through pivot pins, and that on the steering mechanism there is arranged a bowed steering arm which extends over the space between the steerable wheels and the front edge of the seat.

3. An invalid carriage according to claim 2, characterised in that the bowed steering arm has at least the same width as the seat.

4. An invalid carriage according to claim 2 or 3, characterised in that the bowed steering arm is adapted to pivot about a pivoting axis situated transversely relatively to the vehicle axis.

5. An invalid carriage according to claim 4, characterised in that the upper limit position of the bowed steering arm is defined by a fixed abutment at a height of about 50 centimetres above the seat, for the front edge of the bowed steering arm.

6. An invalid carriage according to claim 5, characterised in that the bowed steering arm is loaded by a spring force acting in the direction towards the upper limit position.

7. An invalid carriage according to claim 4, characterised in that the lower limit position of the bowed steering arm is defined by a slide pressure plate which is connected with a vehicle brake by way of adjusting elements.

8. An invalid carriage according to claim 7, characterised in that the slide pressure plate is lockable in its lower limit position - with the vehicle brake applied.

9. An invalid carriage according to claim 1 or 2, characterised in that the pivot pins of the two steerable wheels are arranged at the two sides on a bridge bar and that the bridge bar is held. with interposition of elastic pressure elements, in a bridge member connected with the chassis.

10. An invalid carriage according to claim 9, characterised in that the pressure elements are rubber springs.

11. An invalid carriage according to claim 1, characterised in that the chassis is formed of a plurality of tubes which are situated parallel to one another in the longitudinal direction of the vehicie.

12. An invalid carriage according to claim 1, characterised in that at a bridge member which supports the steerable wheels through the agency of the bridge bar the tubes are divided and are adapted to be connected to one another by means of coupling sleeves.

13. An invalid carriage according to claim 1, characterised in that batteries of the electric drive unit are arranged in front of the steerable wheels.

14. An invalid carriage according to one or more of the preceding claims, characterised in that outwardly swingable foot rests are arranged above the steerable wheels and laterally of the driving wheel.

15. An invalid carriage according to one or more of the preceding claims, characterised in that the front edge of the vehicle is formed of a bumper which can be pushed-in in opposition to spring force.

16. An invalid carriage according to claim 15, characterised in that behind the bumper there is arranged a limit switch which switches off the forward propulsion.

17. An invalid carriage according to claim 1, characterised in that the seat is a manually movable wheel chair which can be pushed over the driving wheel and secured in the desired position.

18. An invalid carriage according to claim 17, characterised in that the driving wheel is mounted on the three-wheeler chassis by means of pivotable spring legs.

19. An invalid carriage according to claim 18, characterised in that the spring legs are adapted to be displaced into the two limit positions by means of an adjusting device which can be adjusted with an electric driving motor.

20. An invalid carriage according to claim 19, characterised in that the seat accommodating means at the upper side of the three-wheeler chassis comprise pairs of levers which can be pivoted upwardly by means of the adjusting device.

21. An invalid carriage according to claim 17, characterised in that laterally of the driving wheel there are arranged two run-on ramps which are capable of pivoting about pivot pins situated behind the centre of gravity of the wheel chair when mounted in place on the three-wheeler chassis.

22. An invalid carriage according to claim 21, characterised in that the said ramps are connected to one another by means of a cross-member, and between the cross-member and the three-wheeler chassis there is arranged a securing pneumatic spring which presses the ramps into the run-on position.

23. An invalid carriage according to claim 21 or 22, characterised in that above the driving wheel a guide rail is provided for the wheel chair.

24. An invalid carriage according to one of claim 21, 22 or 23, characterised in that above the driving wheel there is arranged a traction device for latching on to the wheel chair and being driven by an electric motor.

25. An invalid carriage according to claim 21, characterised in that the said ramps are provided with end rollers.

26. An invalid carriage according to one or more of the preceding claims, including a manually movable wheel chairwhich is provided with a seat turntable.

27. An invalid carriage substantially as herein described with reference to the accompanying drawings.