Wheelchair lift with wheelchair barrier platform interlock mechanism

摘要

A platform-type wheelchair lift for mounting in the stairwell of a vehicle, such as a bus or train. The wheelchair lift includes a platform frame that is movable from a retracted position in which it is stowed underneath the vehicle to an extended position in which it extends out from the side or back of the vehicle. A wheelchair platform is movably coupled to the platform frame by a parallelogram linkage that allows the wheelchair platform to move between a lowered and a raised position. The wheelchair platform includes foldable outer and inner wheelchair barriers that prevent a wheelchair from moving off of the wheelchair platform during operation of the wheelchair lift. The wheelchair platform also includes a mechanical platform interlock mechanism. The platform interlock mechanism is moveable between an unlocked and a locked position. The platform interlock mechanism is in an unlocked position when no weight is placed on the wheelchair platform. In the unlocked position, the platform interlock mechanism allows the outer barrier to move between an upright barrier position, and a retracted position in which the barrier lies adjacent an upper surface of the wheelchair platform. When a weight such as a person or wheelchair is located on the wheelchair platform, the platform interlock mechanism moves into a locked position in which the outer barrier is prevented from moving between the upright position and the retracted position.