Patent attributes
A hydraulic level-adjustment device has a reservoir, a reversible hydraulic unit with a hydraulic pump, and a single-acting hydraulic linear actuator. To lift a vehicle chassis, the working space of the linear actuator can be pressurized by the hydraulic pump operated in its first pumping direction via its first pump connection and a fill line with a fill-check valve arranged therein. To lower the chassis, via its second pump connection, the hydraulic pump, operated in the reverse pumping direction, pumps hydraulic fluid into the reservoir via an outflow line with a throttle unit arranged therein. The pressure present upstream of the throttle unit acts on the control connection of a lockable, drainage-check valve via a control line and opens same, so that, under the weight of the motor vehicle, hydraulic fluid is forced out of the working space of the hydraulic linear actuator into the reservoir via the drainage line.
