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 5 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.

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 5 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.

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.

Abstract: The present invention relates to hydraulic circuit capable of independently controlling a plurality of hydraulic cylinders or actuators. The hydraulic circuit includes a set of independently energizable valves fluidically positioned in the circuit and capable of, when selectively energized and de-energized, functionally isolating specific circuit elements. In one preferred embodiment, the present invention relates to a hydraulic circuit for independently controlling the stowage functions, vertical movement, and rollstop operations of a wheelchair-lifting platform. Another preferred embodiment of the present invention relates to a wheelchair lifting platform having a lifting cylinder and a rollstop cylinder and incorporating a hydraulic circuit capable of independently actuating and controlling the respective cylinders.

Abstract: A wheelchair lift having a foldable platform including a first platform portion foldably coupled to a second platform portion, a lifting frame, at least one lifting arm with one end pivotally coupled to the lifting frame and the other end connected to the second platform portion and adapted to pivot the lifting arm between a substantially vertical stowed position and a substantially horizontal deployed position. A post extends from the lifting arm and a locking assembly is pivotably coupled to the lifting frame. The locking assembly includes a lever arm pivotably coupled to the lifting frame, a gas spring extending between the lever arm and the lifting frame which operates to resist pivoting of the lever arm, and a mechanical spring extending between the lever arm and the lifting frame which exerts a biasing force operating to pivot the lever arm to engage the post.

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.

Abstract: In a preferred embodiment, the present invention incorporates a fluid pressure sensing switch in fluid communication with a hydraulic fluid outlet of a hydraulic pump driving a platform lift. The pressure switch is calibrated to activate at a pump outlet pressure created when the pump attempts to lift (fold) the platform into the stow position when it carries a load. The switch is calibrated not to activate at a pump outlet pressure created when the pump attempts to lift (fold) the platform into the stow position when the platform is unloaded. Activation of the pressure switch disables the hydraulic pump, thereby preventing a loaded platform from being folded into the stow position.

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.

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.

Abstract: Improvement in wheelchair lifts generally of the dual hydraulic parallelogram type employing a lever arm assembly which assists in the rotation of the platform from the stowed position to the horizontal deployed position, by providing a gas spring disposed in the lever arm assembly connected at an outboard end to the lifting mechanism link and at an inboard end to at least one of the A arm, the B arm or the common pivot pin of the lever arm assembly. The outward force of the gas spring causes the sliding shoe of the lever arm assembly to maintain contact with the outer face of the lower link of the lifting parallelogram so that upon deployment of the lift during the gravity down phase from stowed position to horizontal transfer position, the inboard end of the platform is pulled up so that it rotates smoothly and is not subjected to free fall.

Abstract: A wheelchair platform free fall control system comprising use of a tension means, such as at least one spring, biasing together the long and short arms of a lever arm assembly that keeps the lever arm slide block in contact with a lifting arm during gravity-down deployment of said platform from an over-vertical stowed position to a horizontal transfer position. A compression means may be used in conjunction with the lifting arm assembly to assist in overcoming the resting momentum of the lift platform mass from over-vertical outwardly until gravity takes over. The tension means may be one or more springs and the compression means may be a gas spring. The forces are preselected to provide lifting assembly over-vertical assist while keeping the sliding block in substantial contact with an arm of the lifting assembly. The springs can be used with a stud/slot interlock. Torsion springs are preferably eliminated.

Abstract: A flow compensator valve for use in a hydraulic system which includes a cylindrical body having inlet and outlet ports, and a slidable, spring-biased hollow piston insert disposed within a center bore of the body, which insert has a plurality of ports for flow control depending on the position of the insert as it reciprocates axially within the center bore of the valve body. In a preferred embodiment, the valve is used in connection with a hydraulically actuated lift which is particularly useful for assistance of handicap persons for vans and mass transit vehicles. The axially-reciprocable, spring-biased flow rate controlling insert has a small central axial bore for slow lift movement in the loaded condition and at least one larger transverse bore, which when exposed, permits flow therethrough for faster movement of the lift in the unloaded condition.