GB2306435A

GB2306435A - Vehicle Wheelchair Lift

Info

Publication number: GB2306435A
Application number: GB9521659A
Authority: GB
Inventors: Andrew Simon Mynheer
Original assignee: Individual
Current assignee: Individual
Priority date: 1995-10-23
Filing date: 1995-10-23
Publication date: 1997-05-07
Anticipated expiration: 2015-10-23
Also published as: GB9521659D0; GB2306435B

Abstract

Vehicle wheelchair lift comprises a platform 2A for supporting a wheelchair, means 3 for raising and lowering the platform, means 5 for moving the platform sideways in a raised position, and a control means 64, wherein the platform is locatable in the vehicle to support the wheelchair in a driving or front seat position for the user, the platform is movable between said internal position and a wheelchair transfer position on the ground outside the vehicle, and the control means is operable by a wheelchair user without aid. Preferably: (i) a guide means 10 is mounted or mountable within a vehicle for partial rotational movement, and (ii) the platform forms part of a load hearing member 2 connected to the guide means for generally vertical reciprocating movement relative to the guide means and pivotal movement together with the guide means. Preferably, the platform is raid by a hydraulic motor 3 and rotated by an electric motor 4 and gearing 5.

Description

LOADING LIFT FOR VEHICLES The present invention relates generally to lifts for raising loads into and out of vehicles. More particularly it relates to a system for lifting wheelchairs in and out of vehicles. However the system could be adapted e.g. for assisting deliveries from small vans, especially those fitted with side-opening doors.

Known systems for lifting disabled persons fall into three types: One type uses a cable hoist to raise a flexible chair. This is sometimes called a "basket" system. Its principle disadvantage is that it is necessary for an assistant to lift a disabled person from a wheelchair to the lift chair and afterwards from the latter to a car seat. The user feels insecure and is often knocked about.

Another system e.g. as described in US-A-5261779 employs a "parallelogram" linkage to raise a platform carrying a wheelchair to floor level in a vehicle without a door sill. An assistant then pushes the wheelchair into the car and manipulates it to a suitable position. The linkage can then be folded up to allow the door to close.

The type to which the present invention is more closely related is a "rotary" type of lift as described in e.g. US-A-4664584 and WO 92/21532. In the known lifts, a platform, which can be extendible, is raised by a hydraulic actuator on a guide which itself swings through an arc on swivel arms about an off-set vertical axis from an external position facing backwards parallel to the vehicle to a position within the vehicle facing the side door. Rotation is accomplished by an actuator and lever mechanism. The wheelchair is then rolled off the platform which folds up for storage. The known lifts again require the presence of an assistant and manipulation of the wheelchair within the vehicle. The requirement for folding and the use of an actuator connected to the platform via chains and pulleys, lead to a complicated and expensive mechanism.

There is a need for a lift system which can be operated throughout by a disabled person without assistance and which enables him or her to arrive without interior manipulation in a secure driving position or, alternatively or in addition, in a front passenger position. An aim of the invention is to fulfil this need. There is also need for a lift system which is simple and robust, which can be used on small passenger cars which are normally fitted with door sills, and which can be used in other applications such as raising and lowering delivery loads from relatively small vehicles.

According to one aspect the invention provides a system for lifting wheelchairs in and out of vehicles comprising a load bearing member with a platform for supporting a wheelchair, means for raising and lowering the platform, means for moving the platform sideways in a raised position, and a control means, wherein: (a) the platform is locatable in the vehicle to support the wheelchair in an internal driving position or front passenger positiion for the user, (b) the platform is movable between said internal position and a wheelchair transfer position on the ground outside the vehicle, and (c) the control means is operable by a wheelchair user without aid.

According to a second aspect the invention provides a system for lifting wheelchairs or other loads in and out of vehicles comprising a load bearing member, means for raising and lowering the load bearing member, means for moving the load bearing member sideways in a raised position, and a control means, wherein:: (i) a guide means is mounted or mountable within a vehicle for partial generally horizontal rotational movement without translational movement, (ii) the load bearing member is supported upon the guide means for generally vertical reciprocating movement relative to the guide means and rotational movement together with the guide means, the load bearing member being laterally off-set from the guide means so as to swing through an arc during rotation of the guide means between positions horizontally within and outside the vehicle, the system including (iii) first activating means for activating the rotational movement of the guide means, and (iv) second activating means for activating the reciprocating movement of the load bearing member, and wherein the control means is operable to energise the first and second activating means in an appropriate sequence for movement of the load bearing member between an internal position within a vehicle and a load transfer position with the load bearing member adjacent to the ground outside the vehicle.

Preferably the second activating means is fixed to the guide means for rotation therewith.

The guide means is preferably mounted between upper and lower tapered roller bearings, the upper one being preferably tapered upwardly and the lower one downwardly. In this way the load bearing member is supported by the bearings both axially and laterally. The bearings may be mounted directly to the car body, but preferably they are mounted to a cradle, e.g. of steel having two C frames at right angles, with the lower part of the cradle secured to the vehicle floor and the upper part, by a horizontal support member, to the adjacent car door post. This provides additional support for the load when extended outside the car.

In the preferred embodiment to be described, the guide means comprises a vertical post upon which the load bearing member is mounted for vertical sliding reciprocation, preferably via upper and lower PTFE or equivalent bearings. The first activating means may comprise an electric motor and reduction gearing and the second activating means a hydraulic ram which is preferably fixed to post for horizontal movement therewith, e.g. via an arm fixed to the post adjacent its lower end.

The load bearing member may be generally L shaped with a generally horizontally extending platform and a generally vertically extending carriage member. The actuator preferably comprises a piston rod connected to carriage member adjacent its upper end. preferably includes a platform which may be arranged, e.g. with appropriate guides and safety ramps, for supporting a wheelchair or which may be a simple structural floor member suitable for various loads or which, if desired, may be telescopically extendible.

A preferred outward sequence of movement of the load bearing member includes: (a) first upward movement of the load bearing member relative to the guide means from an internal position with said platform resting on the vehicle floor in a driver or front passenger situation to an inward hoisted position, (b) rotational movement at said inward hoisted position to an outward hoisted position with the platform clear of the vehicle side, and (c) downward movement of the load bearing member at the outward hoisted position to a transfer position with the platform resting on the ground, the inward sequence consisting essentially of a reverse sequence of movements.

With this sequence of movements the platform may be lifted to a rotation level above the level of any vehicle door sill.

As will become apparent the control means in the embodiment is operable by a wheelchair user without aid for movement of the wheelchair into and out of the vehicle.

An embodiment of the invention is described below with reference to the accompanying drawings, in which: Figure 1 is a perspective view of a wheelchair lift system (the "lift") before installation, Figure 2 is a view in side elevation showing part of the lift, Figure 3 is a diagrammatic plan view (from the top) of the lift installed in the left front seat position of a car, showing the two rotational end positions of the wheelchair supporting platform, Figure 4 is a laterally exploded downward perspective view from the side showing the three principal component structures of the lift, Figures 5 (a), (b) and (c) together form an exploded downward perspective view with parts shown in cross-section of the cylindrical guide or post, together with its upper and lower bearings and Figure 6 is a similar perspective and cross-sectional view of the bearing assembly for vertical movement of the load bearing member and platform.

Figures 1 and 2 show a system 1 for lifting wheelchairs in and out of vehicles, comprising a generally L shaped load bearing member 2 with a generally horizontally extending platform 2a and a vertically extending carriage member 2b, means comprising a hydraulic actuator 3 having a cylinder 3a and piston rod 3b for raising and lowering the load bearing member 2 and means comprising an electric motor 4 and reduction gearing 5 for moving the load bearing member and platform sideways in a raised position.

As seen in Figure 3, which is a view looking downwards on to the lift system installed in the left front seat position of a car, the platform 2a rests, in the internal end position 1, on the car floor facing forwards as indicated by the broken line arrow C marking the central vertical axial plane of the car. In left hand drive cars this position, to the right in Figure 3, will be the driving position. The hatched area at 6 shows the side wall of the car and that at 7 the left front door post, the open door being indicated at 8.It can be seen from Figure 3 that the load bearing member 2 is rotatable about the vertical axis X of a cylindrical post, 10 constituting a guide means, about an angle of generally 90 , in the direction of the broken line arrow R so that the platform reaches an outward hoisted position T where the platform is outside the bounds of the car facing away from its side.

When the platform is so situated it can be lowered to rest on the ground outside the car in a wheelchair transfer position where the user of the wheelchair can move himself or herself off the platform.

As seen in Figure 4, the lift system 1 is essentially constituted of three individually integral parts A, B and C which are articulated together.

Part A comprises a mounting cradle 11 adapted to b fixed within a vehicle. The cradle 11 comprises two generally C shaped frames 11a and lib positioned at right angles. Lower arms 12a, 12b of the cradles are in use bolted to the floor of the vehicle which may if necessary be suitable strengthened. At their ends, the arms 12a, 12b are connected e.g. by welding to a lower bearing cup 13. Uprights 14a, 14b connect the respective lower arms to respective upper arms 15a, 15b similarly connected to an upper bearing cup 16. The arms and uprights may be formed of steel strips welded to form rectangular section tubes (Figure 3).From Figure 3 it will be apparent that the frame Ila will support the weight of the load during raising and lowering movement outside the vehicle and the frame 11 b will support the weight of the load within the car when the platform is not in contact with the floor.

While the cradle will normally be welded or bolted to a strengthened floor of a car, certain strongly constructed cars may not need strengthening. However it is normally desirable to secure the nearest cradle arm (e.g. 15b) or upright (e.g.

14b), at a level near the top, to the rear doorpost for additional strength.

A mounting plate 17 extending from the side of the upper cup 16 serves to mount the electric motor 4 and reduction gearing 5 for rotating the post 10.

Although not shown in detail, the reduction gearing may for example consist of a worm gear 19 coupled to a small pinion gear 20. The small gear 20 meshes with a large pinion gear 21 fixed to the post 10. The specification of the motor and gearing may vary with the particular application but in one example a proprietary 24 v, 32 w motor is used, driven by a 12 v battery (e.g. the vehicle battery) to reduce the designed speed of the motor to approximately half. The motor is obtained coupled to a worm gear having a ratio of about 1:8 with a designed output speed of 125 rpm, which is reduced to about 60 rpm by voltage reduction.

The output shaft of the worm gear is coupled to a sprocket gear having a ratio of 1:5 (12 teeth to 60) to provide a rotational speed for the post 10 of about 12 rpm.

The rotational speed of the post 10 (and consequently of the platform 2a) should generally be within the range of 5 to 15 rpm. Obviously an appropriate 12 v motor could be used.

Part B (Figure 4) consists of the rotatable post 10 and the attached hydraulic actuator 3. The post 10 can be of any desired cross-section, e.g.

square, since part C, although slipping up and down the post, is designed to rotate with it. However a cylindrical cross-section is chosen in this embodiment for economy of construction, since slip bearings of any other cross-section would be difficult and expensive to construct. Coupling of the piston 3b of the actuator 3 to part C prevents any relative rotation of the two parts. However additional means may if desired be used to reduce any strain on the piston and coupling, e.g. the provision of one or more longitudinal grooves in the post and the insertion of one or more balls or rollers between the grooves and sockets in the slip bearings to be described.

As shown in Figure 3, the large sprocket gear 21 is fixed to the upper end of the post 10. The detailed construction of the post and its gear and bearings is shown in Figures 5 (a) to (c). Turning to Figure 5 (a), a hardened steel upper plug 22 seats within the upper bearing cup 16 which is bored with an axial aperture 23. A threaded axial socket 24 is present in the upper plug 22 into which is loosely screwed a large diameter Allen bolt 25 which may be reached through the aperture 23 by a hexagonal tool to adjust its position. Unscrewing the bolt 25 will press the plug 22 downwards to clamp the bearings in place.

Likewise the bearings and post can be removed by fully screwing down the bolt 25.

The upper roller bearing proper consists of outer bearing ring 26 with a frustoconical inner face, inner bearing ring 27 with a frustoconical outer face and rollers 28. The inner bearing ring 27 seats as a machined fit within a ring shaped recess 29 in a rim portion 31 of a hardened steel lower plug 32. Although shown as a separate part, the lower plug 32 is seam welded to the upper edge of the post 10.

The large sprocket gear 21 has an inner rim 33 which fits over plug 32 and is a tight machined fit over a recessed portion 34 of post 10. To prevent relative rotation, keyways 35 and 36 in the gear and post respectively are connected by a key 37.

The lower roller bearing is similar to the upper bearing but in inverted relationship. Thus plug 38 is similar to plug 32 and is seam welded to the lower end of the post 10. Inner bearing ring 39 is similar to ring 27, outer bearing ring 40 is similar to ring 26 and the rollers 41 are similar to the rollers 28. The lower bearing cup indicated at 13 in Figure 4 is formed of a cup shaped part 13a which seats the outer ring 40, welded to a projecting portion 13b of the cradle 11.

Returning to Figure 4, the cylinder 3a of actuator 3 rests on a short arm 41 composed of steel plates welded in rectangular section to a lower end portion of the post 10. Cylinder 3a is also strapped by curved bar 42, threaded at the ends, to a horizontally curved steel support plate 43 welded to the arm 41 and extending upwards against most of the length of cylinder 3a. As shown more clearly in Figure 2, an enlargement at the upper end of the piston rod 3b is coupled by a high tensile steel pin 44 of e.g. 15 mm diameter to the cross bars of two upright inverted U shaped brackets 45a and 45b formec of welded steel plate.

The brackets 45a and 45b are welded to the top of an inverted U shaped steel upper connecting member 46 which is welded at the right hand end as viewed in Figure 4 (at the left hand end in Figure 2) to carriage member 2b of the load bearing member 2. Two generally C shaped lower connecting members 47 are similarly welded lower down on respective sides of the actuator cylinder 3a. The other ends of the connecting members 46, 47 are welded to the near side plate of a box shaped welded steel bearing holder 48 (Figures 2, 4) which holds the bearings by which the load bearing member 2 slides on the post 10.

The actuator 3 in the example already mentioned is designed for a load of 1 ton (1.016 tonne) which is more than sufficient for lifting a wheelchair and user.

It has a maximum stroke of 18 ins. (45.7 cm) but a stroke of 14 ins. (35.6 cm) is normally sufficient for use in small vehicles. It is driven by a pump 49 housed in a recess in the rear of the load bearing member 2 (Figure 4) through pipe 50. The pump is only used for raising the load; lowering of the load is permitted by an adjustable pressure release valve (not shown) through which fluid returns to the pump.

The construction of the bearing holder 48 is best viewed in Figure 6. The sides of the holder are of steel plate bent and welded to define a square section container 51 open at each end. Holder plates 52 and 53 are welded at slightly recessed positions respectively at the top and bottom of the container. The plates 52, 53 are bored to receive flanged TEFLONS (PTFE) bearings 54, 55 which require no lubrication. As shown the flanges are bolted to the holder plates 52, 53.

As shown in Figure 4, the bearing holder 48 is rigidly connected to the load bearing member 2 by the actuator coupling assembly 46, 47, 45a, 45b. The load bearing member comprises a framework of welded square or rectangular sectioned tubular steel frame members 56, some of which are shown in Figures 2 and 4, but which extend also under the press-formed steel plate 57 (Figure 1) which defines the surface of the platform 2a and the carriage member 2b. The actuator assembly and the plate 57 are welded to the steel framework. The plate 57 is press-formed in the embodiment shown to define surface formations adapted to receive a wheelchair in a secure position for lifting. Thus indented tracks 58 are formed near the edges of the platform portion to receive the wheels of the wheelchair.Ramps 59 are formed at the forward edges of the tracks which also extend obliquely upwards at the rear to form abutments for the wheels. A wheelchair user may quite easily ride the large rear wheels of the wheelchair backwards over the ramps 59, but the small diameter front wheels are found to be secure against forward rolling when the wheelchair is in position To exit from the platform requires a deliberate thrust by the user, which can be assisted by leaning backwards. A central inverted V shaped section 60 of the plate 57 strengthens the plate and frame assembly and provides a convenient housing for the pump 49. Curved guide plates 61 may be welded to the plate 57 to assist in guiding the wheels of the wheelchair into the tracks 58.

A welded steel stand 62 (Figure 1) forming part of the supporting framework is welded to a box shaped holder 63 into which can be placed a control box 64 in a position easily reached by the wheelchair user. The control box is attached by an umbilical control cable 65 to a circuit board behind the plate 57 at the top of the load bearing member 2. The control box is fitted (in the present embodiment) with a keyed power switch, a (green) button for raising the platform, a (red) button for lowering the platform and a left/right (out/in) toggle switch for activating left and right rotation of the platform.

The length of the umbilical cable 65 is sufficient to allow the user of the wheelchair to re-position the control box in the position 64' shown in broken lines in Figure 3, where it can be hooked on to the cradle upright 14b.

As is well known in the art, the operation may be fully controlled by electric or electronic controls using relays and solenoid switches for operation of the motor and actuator. A single switch may initiate the whole necessary sequence of movements for loading or unloading. However it has been found quite possible to switch the rotation motor on or off directly and either to switch on the pump for a raising movement or activate a solenoid to temporarily open the pressure release valve for a lowering movement. Welded mechanical stops 66 on the cradle uprights 11a, 11b (Figure 1) ensure that the rotation is stopped in the correct positions. Similar mechanical stops (not shown) are used to control the upper and lower end positions of the load bearing member. These are preferably made adjustable to allow for differing vehicle floor heights.Clearly, electric stop switches may be employed alternatively or in addition as desired. To allow for different pavement or sidewalk levels it is desirable to employ a stop switch on the platform at its lower level to halt the downward movement when the ground level is reached.

The embodiment described is designed for use in cars or vans which are normally constructed with door sills above the level of the interior floor. To overcome this problem the hydraulic actuator 3 is arranged so that the level of the rest position of the load bearing member in the car is reached some distance from the fully extended position of the piston 3b. This allows the user to raise the platform before rotation to a stop indicating a correct level for rotation, above the level of the door sill. A safety circuit be used to ensure that rotation is not activated at the wrong level.

The following describes the sequences of operations employed by the Starting with the user in the wheelchair at the roadside, he positions him/herself to unlock the car and open the door. The control box at this time is in the position 64' on the upright 14b near the rear door post. The view in Figure 3.

is not to scale and the user can easily reach the control box and unhook it.

Positioning him/herself clear of the doorway he/she uses the control box to lift the platform to the inward hoist position and then switches the toggle to rotate the platform out to the outward hoist position. When this position is reached he/she uses the control box to lower the platform to the ground. During these operations the control box may be in position on the stand (Figure 1) or held in his/her hand.

The user then manipulates him/herself backwards over the ramps into the tracks on the platform and puts the wheelchair brakes on. When in position with the control box in the holder 63 he uses it firstly to lift the platform to the outward hoist position, then rotates to the inward hoist position facing forward above the level of the door sill, and finally downwards to floor level.

Clearly various safety features may be employed such as locks, bars or unfolding ramps to secure the wheelchair on the platform. However in practice, with the wheelchair brakes on, the user is found to be very secure. He/she can hold on to the side frame member 67 securing the stand 62, which serves as a banister. When in the car, conventional seat belts can be used. The wheelchair is more secure against backward movement than a normal front driver or passenger seat. A head rest may be attached to the top of the carriage member if desired.

The present invention allows disabled persons in wheelchairs full unassisted use of a car or other road transport either as a passenger or driver.

As already described, he/she can leave the car and lock it and return to drive away. Left-rotating or right-rotating versions can be constructed and fitted depending on the country of use and whether driver use or passenger use is required.

The invention has uses also for loading and unloading e.g. from small delivery vans or similar vehicles There is a clear need for such lifts since quite heavy loads are often carried and manipulation into and out of such vehicles is the primary difficulty. The unit may be positioned if desired near the rear door of vans and the platform constructed as a simple level floor or e.g. fork. Telescopic extending platforms of known construction provide another alternative.

While many of the components are described as constructed of steel, alternative materials can be used. E.g. the cradle could be made of aluminium and the formed platform shhet of composite such as g.r.p. or carbon fiber.

Claims

1. A system for lifting wheelchairs in and out of vehicles comprising a load bearing member with a platform for supporting a wheelchair, means for raising and lowering the platform, means for moving the platform sideways in a raised position, and a control means, wherein: (a) the platform is locatable in the vehicle to support the wheelchair in an internal driving position or front passenger position for the user, (b) the platform is movable between said internal position and a wheelchair transfer position on the ground outside the vehicle, and (c) the control means is operable by a wheelchair user without aid.

2 A system for lifting wheelchairs or other loads in and out of vehicles comprising a load bearing member, means for raising and lowering the load bearing member, means for moving the load bearing member sideways in a raised position, and a control means, wherein: (i) a guide means is mounted or mountable within a vehicle for partial generally horizontal rotational movement without translational movement, (ii) the load bearing member is supported upon the guide means for generally vertical reciprocating movement relative to the guide means and rotational movement together with the guide means, the load bearing member being laterally off-set from the guide means so as to swing through an arc during rotation of the guide means between positions horizontally within and outside the vehicle, the system including (iii) first activating means for activating the rotational movement of the guide means, and (iv) second activating means for activating the reciprocating movement of the load bearing member, and wherein the control means is operable to energise the first and second activating means in an appropriate sequence for movement of the load bearing member between an internal position within a vehicle and a load transfer position with the load bearing member adjacent to the ground outside the vehicle.

3. A system according to claim 2 wherein the second activating means is fixed to the guide means for rotation therewith.

4. A system according to claim 2 or claim 3 wherein the guide means is mounted between upper and lower tapered roller bearings

5. A system according to any of claims 2 to 4 wherein the upper bearing is an upwardly tapered roller bearing.

6. A system according to any of claims 2 to 5 wherein the lower bearing is a downwardly tapered roller bearing.

7. A system according to any of claims 2 to 6 wherein the guide means comprises a vertical post upon which the load bearing member is mounted for vertical sliding reciprocation.

8. A system according to claim 7 wherein the load bearing member is supported for sliding movement on the post via upper and lower PTFE or equivalent bearings.

9. A system according to claim 7 or claim 8 wherein the post is cylindrical.

10. A system according to claim any of claims 2 to 9 wherein the first activating means comprises an electric motor and reduction gearing.

11. A system according to any of claim 2 to 10 wherein the second activating means comprises a hydraulic ram.

12. A system according to claim 11 wherein the ram has a cylinder mounted on an arm fixed to the post adjacent its lower end.

13. A system according to claim 11 or claim 12 wherein the load bearing member is generally L shaped with a generally horizontally extending platform and a generally vertically extending carriage member, and the actuator comprises a piston rod connected to the carriage member adjacent its upper end.

14. A system according to any of claims 2 to 13 wherein the load bearing member includes a platform arranged for supporting a wheelchair.

15. A system according to any of claims 1 to 14 wherein the outward sequence of movement of the load bearing member includes: (a) first upward movement of the load bearing member relative to the guide means from an internal position with said member resting on the vehicle floor in a driver or front passenger situation to an inward hoisted position, (b) rotational movement at said inward hoisted position to an outward hoisted position with the load bearing member clear of the vehicle side, and (c) downward movement of the bearing member at the outward hoisted position to a transfer position with the load bearing member resting on the ground, the inward sequence consisting essentially of a reverse sequence of movements.

16. A system according to claim 15 wherein the rotation level is above the level of any vehicle door sill.

17. A system according to any of claims 10 to 16 wherein the control means is operable by a wheelchair user without aid for movement of the wheelchair into and out of the vehicle.

18. A system according to any preceding claim wherein the lift system is essentially constituted of three individually integral parts which are articulated together.

19. A system for lifting wheelchairs in and out of vehicles substantially as described herein with reference to the accompanying drawings.