Patent ID: 6029448
Filing Date: 2000-02-29
Classification: B66F,F04B,F15B

Abstract:
A hydraulic power unit for an auto-hoist lift, the power unit comprising:a reservoir for holding hydraulic fluid, the reservoir having a closed end and an open end;a manifold block attached to the open end of the reservoir having an inlet port an outlet pressure port for connection to the auto-hoist lift and a return line for connecting the outlet pressure port to the reservoir, the manifold block carrying a hydraulic circuit located between the ports for controlling the hydraulic fluid delivered by the power unit;a pump driven by an AC motor, the motor and pump located inside the reservoir and submerged in the hydraulic fluid, the pump drawing hydraulic fluid through the motor before delivering the fluid to the lift, the pump having a pump output fluidically connected through the inlet port to the outlet pressure port:a return valve manually actuated by a handle, the return valve located in the return line for selectively venting the outlet pressure port to the reservoir;a check valve disposed between the pump output and the pressure output port for ensuring one directional flow from the pump to the pressure output port; anda pressure relief safety valve connected in fluid parallel with the sump for connecting the pump output to the reservoir at a predetermined pressure.