Patent ID: 11970102
Assignee: HIAB USA INC.
Field: Mechanical elements (Mechanical engineering)
Classification: CPC B  F | IPC B  F

Claim 0:
1. A liftgate assembly comprising:
a liftgate that is movable from a raised position to a lowered position; and
a hydraulic power unit usable to raise the liftgate from the lowered position;
wherein the hydraulic power unit includes an energy-recovery mechanism configured to store energy while the liftgate is being lowered under load, and to use the energy stored by the energy-recovery mechanism subsequently to raise the liftgate;
wherein the hydraulic power unit includes a pump that pumps hydraulic fluid from a reservoir;
wherein the energy-recovery mechanism includes an accumulator that is configured to receive hydraulic fluid while the liftgate is being lowered under load, to store the energy;
wherein a selector for lowering with energy recovery engages the energy recovery mechanism;
wherein the selector engages the energy recovery mechanism only when a load on the liftgate exceeds a threshold load; and
wherein the selector includes a pressure sensor incorporated on the liftgate.