GB2140749A - Wheelchair elevator for passenger vehicles - Google Patents

Abstract

A combination wheelchair elevator mechanism and foot step for a passenger vehicle is provided wherein the foot step 36 automatically assumes a lay-flat configuration forming or resting on the support surface of the wheelchair platform 34 when the wheelchair platform is deployed. <IMAGE>

Description

SPECIFICATION Wheelchair elevator for passenger vehicles This invention relates to wheelchair elevator mechanisms, notably to a combined wheelchair elevator and foot step mechanism suitable for use in passenger vehicles.

Considerable difficulty has been experienced in attempting to provide a wheelchair elevator mechanism which can be used for both pedestrian passengers and wheelchair passengers for entering and leaving passenger vehicles.

In previous proposals, difficulty has been experienced in attempting to insure that a foot step will be automatically deployed when the elevator mechanism is to be used as a foot step by pedestrian passengers. In' one proposal, the foot step is mounted so that it bridges the elevator platform at a required step height above the platform much in the manner of a drawbridge. In this mechanism, the foot step assumes an upright position at one side of the stairwell when the platform is used as an elevator platform and is lowered to bridge the platform when it is to be used as a foot step. However, difficulty has been experienced in maintaining the step in an upright position out of the path of the wheelchair.

We have found that these difficulties can be reduced by providing a step which is movable between a lowered position in which it provides part of the load-bearing platform for the wheelchair and a raised position in which it is forms one of the steps adjacent the platform for a pedestrian user. Thus, when the step is not required, it is stowed in a manner in which it causes a reduced obstruction to the passage of the wheelchair across the platform.

According to one aspect, the present invention provides a mechanism for aiding the access of a wheelchair to a passenger vehicle, which mechanism comprises a platform member adapted to provide at least part of a loadbearing support for a wheelchair; a step member which is adapted to be moved between a first position at which it serves as a step for a pedestrian and a second position at which it provides at least part of the said load-bearing surface; and means for raising or lowering the load-bearing surface.

Preferably, the mechanism is one in which the platform member extends generally horizontally to form a tread portion of the steps at the entry to the vehicle and the tread and riser sections of a step member adjacent the platform member are collapsed to adopt a position as an extension to the platform member or overlie the platform and thereby form the load-bearing surface upon which the wheel chair is supported and lowered. It is also preferred that the platform member adopt the position of a step tread in the retracted position and that it be extended generally horizonfally in co-operation with the step member to form the load-bearing support for the wheelchair.

According to a further aspect of the invention, there is provided a mechanism for aiding access of a wheelchair to a passenger vehicle comprising a platform having a support surface proportioned to provide an underlying support for a wheelchair, guide means mounting said platform for horizontal movement between an extended position and a retracted position, elevator means mounting said platform for movement between a lowered position and a raised position when in said extended position, step means mounted for movement between a lowered position in which it is disposed in a face to face relationship with respect to said platform and a raised position in which it is disposed a substantial distance above said platform to provide a foot step, actuator means communicating with said step mem-ber for affecting movement of said step member in response to horizontal movement of said platform whereby said step is in its lowered position when said platform is in its extended position and is in its raised position when said platform is in its retracted position.

According to a further aspect of the present invention, there is provided in a passenger vehicle elevator means mounted on said side wall, a slipway member mounted on said elevator means for movement between a raised position and a lowered position, said slipway extending in a first direction, a step, a parallelogram linkage pivotally mounting said step on said platform above said support surface for movement between a lowered position in which the step is located in a face-toface relationship with the support surface adjacent the inner end thereof and a raised position disposed one step height above said support surface and one step height below said floor when said platform is in its raised positon, a tie bar connecting said parallelogram linkage and said slipway whereby movement of said platform toward said retracted position causes said linkage to pivot to its raised positon and movement of the platform to the extended position causes the linkage to pivot to its lowered position, means for activating said elevator means to raise and lower said slipway and platform when the platform is in the extended position, means for driving said platform between said extended position and retracted position.

The invention will be described with respect to a particularly preferred embodiment thereof as shown in the accompanying drawings in which; Figure 1 is a pictorial side view of a wheelchair elevator mechanism illustrating in broken lines the location of the mechanism on a passenger vehicle: Figure 2 is a view similar to Fig. 1 showing the wheelchair elevator mechanism in the configuration in which the elevator platform is oriented for use as a wheelchair elevator.

Figure 3 is a partially sectioned pictorial view of the elevator platform with the step located in the raised position.

Figure 4 is a front view of the elevator mechanism of Fig. 1, partially sectioned to illustrate the operating mechanism.

Figure 5 is a sectional view of the elevator mechanism of Fig. 4 taken along line 5-5 of Fig. 4.

With reference to Figs. 1 and 2 of the drawings, the reference numeral 10 refers generally to a wheelchair elevator mechanism constructed in accordance with the the present invention. The mechanism 10 is constructed to fit within the stairwell 12 of a passenger vehicle, such as a bus 14 which has a pair of doors 16 mounted in a doorway 18. The bus has a floor 20 which has a step edge 22 located at the inner end of the stairwell.

The wheelchair elevator mechanism 10 is in the form of a combined wheelchair elevator and foot step mechanism. The mechanism 10 comprises an elevator mechanism generally identified by the reference numeral 30, a guide in the form of a slipway generally identified by reference numberal 32, a platform 34 and a foot step assembly 36.

With reference to Fig. 3 of the drawings, it will be seen that the platform 34 comprises a horizontally orientated bottom wall 40 and a pair of oppositely disposed side walls 42 which extend upwardly from opposite side edges of the bottom wall 40 to form a generally U-shaped enclosure 46 which has a wheelchair support surface 48. The platform 42 has an inner end 50 and an outer end 52.

The step assembly 36 includes a step plate 60, a riser plate 62 and a parallelogram linkage which is generally identified by the reference numeral 64. The step plate 60 consists of a flat plate portion 66 which has upwardly extending side edge portions 68 at opposite ends thereof. The parallelogram linkage includes link arms 70, the outer ends of which are pivotally connected to the end portion 68 of the step plate 60. The inner ends of the link arms 70 extend through elongated slots 72 formed in the bottom wall 40 of the platform and are pivotally mounted by means of pivot pins 74 to the side walls 42 in the platform. The link arms 70 are Lshaped at their lower end to provide an offset which permits the step plate 60 to be lowered to a face-to-face overlying relationship with respect to the support face 46 of the platform 40 as shown in Fig. 2 of the drawings.

The riser plate 62 has its opposite ends secured with respect to the front arms 70 and extends transversely therebetween for movement therewith. A tie bar 76 extends between one of the link arms 70 and a lug 78 which is mounted on the slipway 32. An expandable ram 80 has one end secured by means of a pivot pin 82 to a fixed anchorage and the other end secured by means of a pivot pin 84 with respect to the side wall 42 of the platform.

By activating the ram 80, it is possible to move the platform 36 between the retracted position shown in Fig. 1 of the drawings and the extended or deployed position shown in Fig. 2 of the drawings. In the retracted position shown in Fig. 1 of the drawings, the inner end of the platform is disposed below the floor 20 of the vehicle and the outer end 52 is located inwardly of the doorway 18 to permit closing of the doors 16. In the extended position or deployed position shown in Fig. 2 of the drawings, the platform projects forwardly from the floor 20. In moving between the extended positon and the contracted position, the step 36 is automatically positioned in the lowered position shown in Fig. 2 of the drawings and the raised position shown in Fig. 1 of the drawings.This results from the fact that one end of the tie bar 76 is held against latter movement by the pivot pin 78 such that when the platform is moved to its extended position as a result of movement in the direction of the arrow A of Fig. 3, the tie bar 76 pivots in the direction of the arrow B and comes to rest in the position shown in Fig. 2 of the drawings in which position the step 60 and riser 62 are horizontally oriented and rest in a face-to-face relationship on the support surface 40 of the platform.

The elevator mechanism is best illustrated in Figs. 4 and 5 of the drawings to which reference will now be made. The elevator mechanism 30 comprises a pair of guide posts 90 within which slide members 92 are slidably mounted. A bridge plate 94 extends across the upper ends of the guide posts 90 and one end of a ram 96 is mounted on the bridge plate 94. Roller chains 98 and 98A connect the slide members 92 to stationary mounting fixtures 100 and 1 00A respectively.

The roller chains 98 and 98A extend around sprockets 102 and 1 02A mounted on a head 104 which is carried by the other end of the ram 96. By extending the ram 96, the slide members 92 may be raised and by retracting the ram 96 the slide members 92 may be lowered.

The slipway 32 is formed in beams 110 and 112 which extend transversely between the lower ends of the posts 92. The slipway 32 is in the form of a channel 114 which is formed in the beam 110 and a channel 11 6 which is formed in the beam 112. The inner side wall 42 of the platform 40 has guide rails 118 and 120 extending longitudinally thereof which are proportioned to fit in a close fitting sliding relationship within the channels 114 and 116 respectively to cooperate therewith to permit horizontal movement of the platform.

In use, the wheelchair elevator mechanism is located in the configuration illustrated in Fig. 1 of the drawings when the vehicle is to be driven with the doors closed. In this configuration, a step proportioned to correspond to the proportions of the step normally found on a bus is provided. To prevent the platform extending outwardly from the doorway, the inner end portion 50 is arranged to extend below the floor 20 of the vehicle. When the elevator mechanism is to be used for lowering a wheelchair, the power source (not shown) which activates the ram 80 is connected to the ram 80 to cause it to extend. Extension of the ram 80 causes the platform to deploy to the position shown in Fig. 2, wherein the inner end 50 of the platform is located outwardly from the step edge of the'floor 20 of the vehicle.As previously indicated, movement of the platform from the position shown in Fig. 1 to the position shown in Fig. 2, causes the step 36 to articulate to its lay-flat position. When the platform 34 is in this configuration, it may be raised or lowered as required to the level of the bus floor or through the open lower end of the stairwell to extend to ground level. When in this configuration, a wheelchair may be wheeled onto and off of the platform so as to be raised or lowered as required in use.

From the foregoing it will be apparent that the wheelchair elevator mechanism of the present invention is a mechanism which is capable of performing the dual functions of a wheelchair elevator and a pedestrian step. By causing the step to collapse in response to movement of the platform to the configuration required for wheelchair access, the step is conveniently stowed in a configuration in which it will not present a significant obstacle to the movement of a wheelchair across the platform. The step deployment mechanism is in the form of a simple parallelogram linkage which can be easily serviced and permits the provision of a riser plate in addition to a step plate. The riser plate is an important safety feature of the step in that it serves to reduce the likelihood of a pedestrian passenger tripping when using the step to enter the vehicle.

As indicated above, the step members need not be collapsed to lie upon the wheelchair platform, but can form part of the overall platform itself. Thus, the base 40 of the U shaped member 34 can be provided by a shortened base which extends rearwardly only to the foot of the riser of the step member 36.

This shortened base acts as the tread portion of the lowest step when the assembly of the invention is in the step configuration, but combines with the tread and riser portions of the step member to form the load-bearing surface of a wheelchair platform when the platform is extended to receive a wheelchair.

The platform thus formed is supported by the front and rear edges of member 34 and the pivot points 74 of the step member.

Claims (11)

1. A wheelchair elevator mechanism for aiding the access of a wheelchair to a passenger vehicle, which mechanism comprises a platform member adapted to provide at least part of a load-bearing support for a wheelchair; a step member which is adapted to be moved between a first position at which it serves as a step for a pedestrian and a second position at which it provides at least part of the said load-bearing surface; and means for raising or lowering the load-bearing surface.

2. A wheelchair elevator mechanism as claimed in claim 1 wherein the platform member extends generally horizontally to form a tread portion of the steps at an entry to the vehicle and the tread and riser sections of a step member adjacent the platform member are collapsed to adopt a position as an extension to the platform member or overlie the platform member and thereby form the loadbearing surface upon which the wheelchair is supported.

3. A wheelchair elevator mechanism for a passenger vehicle comprising: a) a platform having a support surface proportioned to a provide an underlying support for a wheelchair b) guide means mounting said platform for horizontal movement between an extended position and a retracted position c) elevator means mounting said platform for movement between a lowered position and a raised position when in said extended position d) step means mounted for movement between a lowered position in which it is disposed in a face to face relationship with respect to said platform and a raised position in which it is disposed a substantial distance above said platform to provide a foot step e) actuator means communicating with said step member for affecting movement of said step member in response to horizontal movement of said platform whereby said step is in its lowered position when said platform is in its extended position and is in its raised position when said platform is in its retracted position

4. A wheelchair elevator mechanism as claimed in any one of the preceding claims wherein said platform comprises a bottom wall and a pair of oppositely disposed side walls arranged in a generally U-shaped confi gyration.

5. A wheelchair mechanism as claimed in Claim 3, wherein said guide means comprises a slipway mounted on said elevator means for movement therewith and a slide rail mounted on said platform and slidably mounted in said slipway.

6. A wheelchair elevator mechanism as claimed in any one of the preceding claims, wherein said step member is mounted for movement between a lowered position and a raised position by means of a parallelogram linkage which includes a pair of link arms at each end of the step, each link arm having a first end pivotally mounted on the step and a second end pivotally mounted on the platform, and tie means having a first end pivotally connected to said parallelogram linkage and a second end pivotally mounted on a portion of the elevator mechanism which does not move laterally with the platform whereby said tie means is operable to raise and lower said step as aforesaid when said platform moves laterally between the extended and retracted positions.

7. A wheelchair elevator mechanism as claimed in claim 3, wherein said step comprises a step plate and a riser plate, the riser plate being pivotally connected to the step plate at a front edge thereof for movement between said lowered position in which said plates are arranged in a side-by-side relationship and a raised position in which said step is horizontally disposed and said riser is vertically disposed and extended from the outer edge of the step.

8. A wheelchair elevator mechanism is claimed in any one of the preceding claims, wherein said elevator means is located at one side of said platform so as to permit substantially unrestricted movement of passengers across said platform.

9. A wheelchair elevator mechanism substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

10. In a passenger vehicle having a doorway leading inwardly therefrom to a stairwell which has a predetermined length in a first direction from the doorway to a step edge to the floor of the passenger compartment, the stairwell having an open lower end and at least one side wall extending in the direction of said predetermined length, the improvement of a combined wheelchair and elevator step mechanism comprising:: a) elevator means mounted on said side wall b) a slipway member mounted on said elevator means for movement between a raised position and a lowered position, said slipway extending in said first direction c) a step d) a parallelogram linkage pivotally mounting said step on said platform above said support surface for movement between a lowered position in which the step is located in a face-to-face relationship with the support surface adjacent the inner end thereof and a raised position disposed one step height above said support surface and one step height below said floor when said platform is in its raised position e) a tie bar connecting said parallelogram linkage and said slipway whereby movement of said platform toward said retracted position causes said linkage to pivot to its raised position and movement of the platform to the extended position causes the linkage to pivot to its lowered position f) means for activating said elevator means to raise and lower said slipway and platform when the platform is in the extended position g) means for driving said platform between said extended position and retracted position

11. A passenger vehicle having fitted to an entry thereto a mechanism as claimed in any one of claims 1 to 9 hereof.