GB2045699A

GB2045699A - Vehicle boarding platforms

Info

Publication number: GB2045699A
Application number: GB8011226A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1979-04-07
Filing date: 1980-04-03
Publication date: 1980-11-05

Abstract

The platform has a step (10) mounted on a vehicle (12) beneath an entrance thereof. The step (10) is moved between extended and retracted positions by means of a double-acting actuator (20) and is guided by paralleled telescopic members (18). Actuator (20) may be hydraulic or pneumatic; if pneumatic it may be powered from the vehicle air brake pressure source. A mechanism may be provided to indicate to the driver when the step (10) is extended. <IMAGE>

Description

SPECIFICATION Improvements relating to vehicles The present invention relates to vehicles and particularly to the provision of movable platforms for vehicles.

One of the problems associated with vehicles such as mobile libraries where access by the public is required is the difficulty of providing easy access where the interior floor of the vehicle is as much as two to four feet above ground. Manually operated folding steps are sometimes provided as are separate stools but these are not satisfactory, particularly in the latter case where it may be difficult to ensure stability.

The present invention seeks to provide an improved movable platform for vehicles.

The present invention provides a movable platform for a vehicle, comprising a base member having a substantially planar surface, means actuable to move the base member between a first retracted position and a second extended position and guide means for maintaining the base member in a substantially horizontal attitude in said second position.

In a preferred embodiment of the present invention the base member is a step which is movable by means of a hydraulically or pneumatically actuable double-acting piston and cylinder unit.

A movable platform according to the present invention is suitable for use as a movable step on vehicles such as mobile libraries, coaches and ambulances where the step can be moved between an extended, in-use position and a retracted position.

The present invention is further described hereinafter, by way of example, with reference to the accompanying drawings in which: Figure 1 is a side elevation, partly in section, of a platform according to the present invention mounted on a vehicle; and Figure 2 is a diagram of a control circuit for the platform of Fig. 1.

Fig. 1 shows a base member in the form of a step 10 mounted on a vehicle 12, only part of which is shown and that being partially in section. A portion of the interior flooring 14 is shown together with a portion of the near side wall 16.

The step 10 is mounted directly beneath an entrance (not shown in the drawings) of the vehicle by means of two paralleled telescopic members 1 8 (only one of which is shown in the drawings) and a double-acting piston and cylinder unit 20. The latter has a piston rod 22 which is pivotally secured to the trailing edge of the step 10 while the remote end of the cylinder is pivotally mounted to the vehicle by way of a bracket 24. Each telescopic member 18 has three arms 26, 28 and 30 the last of which is rigidly secured to the vehicle while the arm 26 is rigidly secured to a respective side of the step 10.

The step 10 is shown in its extended position, the piston and cylinder unit 20 and the telescopic members 1 8 being so arranged to ensure that the step 10 is in a substantially horizontal attitude. While in the described embodiment the step 10 is also maintained in a substantially horizontal attitude in its retracted position (not shown) this is not an essential feature of the invention and the step 10 may be moved into any convenient attitude in its retracted position.

A warning mechanism may be provided to indicate when the step 10 is in its extended position. This is advisable where actuation of the piston and cylinder unit 20 is effected from a remote position for example by a driver of the vehicle. In the illustrated embodiment the warning mechanism comprises a switch 32 which controls an indicator (not shown) such as a lamp and is in turn actuated by movement of the step 10 into its extended position by suitable means such as a spring 34. The latter is tensioned during extension of the step 10 to trip the switch 32.

The piston and cylinder unit 20 is hydraulically or pneumatically operated, preferably being pneumatically operated to enable it to be powered from the same pressure source as that used for the vehicle air brakes, and is controlled by a suitable circuit such as shown in Fig. 2. The piston and cylinder unit 20 has pneumatic ports 36 and 38 at respective ends of the unit, these ports being connected by airlines 40 and 42 to a two-position valve 44 which may be electrically or mechanically operated and is preferably a hand operated valve. The valve 44 connects a selected one of the lines 42, 44 to a source 46 of pressurised gas while venting theother of the two lines 40, 42 to atmosphere.In the position illustrated the valve 44 connects the line 40 to the source 46 thus driving the piston 48 of the unit 20 in the direction indicated by arrow A to extend the step 1 0. The source 46 is preferably the pressure source for the vehicle air brakes.

As an alternative to the spring 34 and switch 32 the valve 44 may itself trip a switch which energises a warning lamp to indicate that the step 10 is extended. The valve 44 is preferably positioned on the vehicle so that it may controlled by the vehicle driver.

Finally, the pressure of the gas applied to the unit 20 is conveniently fifty pounds per square inch. Where the gas is air drawn from the vehicle air brake pressure source a pressure reduction valve (not shown) is preferably connected between the source 46 and the valve 44. In addition, a pressure control valve (not shown) prevents air being drawn from the vehicle air brake pressure source if the pressure of the latter drops to a preselected minimum safety value.

Claims

1. A movable platform for a vehicle com prising a base-member having a substantially planar surface, means actuable to move the base member between a first retracted posi tion-and a second extended position and gu ide means for maintaining the base member in a substantially horizontal attitude in said second position.

2. A-platform as claimed in claim 1 wherein said means actuable to-move the base member comprises a double-actingfoylin- der adapted to be mounted on the vehicle, and said guide means comprises at least two substantially parallel telescopic members, adapted to couple the platform to the vehicle.

3. A platform as claimed in claim2 wherein said cylinder is-pneumatically opera ble.

4. A platform as claimed in claim.3 wherein said cylinder is adapted to be coupled to a pneumatic.braking system of the vehicle by way of a pressure reducing valve.

5. A platform as claimed in claim 2 wherein said cylinder is hydraulically operable.

6. A platform as claimed in any of claims 1 to 5 further comprising a warning mecha nism actuable responsively to extension of the base member to indicate that said base mem ber is extended.

7. A movable platform substantially as hereinbefore described with reference-to the accompanying drawings.

8. A movable platform substantially as hereinbefore described with reference to the drawings accompanying United Kingdom patent application No. 7912321.

9. A vehicle having a movable platform as claimed in any of claims 1-to 8.