Hydraulic circuit for isolating a lifting cylinder from a rollstop cylinder in a wheelchair lift

摘要

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.