CA2226156A1 - Wheelchair lift with wheelchair barrier ground interlock mechanism - Google Patents

Abstract

A platform-type wheelchair lift for mounting in the stairwell of a vehicle, suchas 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 thewheelchair 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 ground interlock mechanism. The ground interlock mechanism is moveable between an unlocked and a locked position. The ground interlock mechanism is in an unlocked position when the wheelchair platform is touching the ground. In the unlocked position, the groundinterlock mechanism allows the outer barrier to move between an upright barrier position, and a fully extended position in which a wheelchair may be maneuvered onto or off of the wheelchair platform. When the wheelchair platform is not in contact with the ground, the ground interlock mechanism moves into a locked position in which the outer barrier is prevented from moving between the upright position and the fully extended position.