Dual function inboard barrier/bridgeplate assembly for wheelchair lifts

Abstract

A dual function, inboard barrier/bridgeplate assembly for wheelchair lifts having a stowable platform, the barrier being pivotably secured to the inboard end of the lift platform, which barrier is actuated by a link to variously raise the barrier' to a safety position and lower it to a bridging position in accordance with the position of the platform. The dual function barrier/bridgeplate system is particularly useful in combination with a parallelogram type lift employing an articulated lever assembly having a sliding block for leveraging the platform from a horizontal transfer orientation to a vertical, or over-vertical stowage position. There is disclosed a barrier assembly in which a spring assist system comprising a gas spring acting on one member of the articulated lever assembly and a lever arm linking a second arm of the articulated lever assembly to the barrier co-operate to actuate the barrier from a raised position when the platform is away from the transfer level and a lowered position to act as a bridge plate at the transfer level. A telescoping push arm is included which actuates the barrier by means of a pivoted link which rotates the barrier in response to the telescoping motion of the push arm. A safety interlock and load detecting system may be employed to prevent the platform from moving to the stowed position when a load greater than a predetermined weight is on the platform. An anti-free fall mechanism is disclosed comprising a pin in the slide block which engages mating slots in the telescoping push arm members to lock their length during the initial stage of deploy of the platform downwardly from the vertical stowed position.