摘要 |
A hydraulic apparatus drives a semi-trailer hitched to a road tractor and a hydraulic equipment device carried by the semi-trailer. The apparatus includes an auxiliary motor capable of driving the device, for example a concrete mixer, through a hydraulic circuit when the vehicle is traveling along the ground, and an electric circuit for controlling valves which, when the vehicle is stationary, put in communication the circuit and a hydrostatic circuit which drives the concrete mixer. The hydrostatic circuit motorizing the semi-trailer is used for alternately driving either the axles of the semi-trailer or the equipment device to be driven. |