US Patent 7500818 Passenger lift with passenger sensitive moveable barrier

A wheelchair lift (100) for a vehicle having a barrier (128) moveable between an access position and a blocking position. The wheelchair lift includes an actuator (152) coupled to the barrier, the actuator adapted to apply an actuation force upon the barrier to move the barrier from the access position to the blocking position. When the barrier is in an unloaded state, the actuation force causes the actuator to move in a first direction resulting in the barrier moving from the access position to the blocking position. When the barrier is in a loaded state, the actuation force causes the actuator to move in a second direction a predetermined amount without causing substantial movement of the barrier.