Abstract: A construction equipment machine has a lower frame and an upper frame rotatably connected, the machine having at least one hydraulic pilot circuit comprising a primary hydraulic pilot line running from the upper frame to the lower frame through a rotary joint for controlling the operation of at least one hydraulic device located on the lower frame, including: a pressure regulating system capable of setting in the pilot circuit a pilot pressure having a value; a hydraulic pressure controlled selecting system which is located on the lower frame and is fed by the primary hydraulic pilot line, at least two independent secondary pilot lines located downstream of the pressure controlled selecting system, and wherein said hydraulic pressure controlled selecting system is capable of selectively and independently supply or not supply pressurized fluid to the independent secondary pilot lines, responsive to the value of the pilot pressure.

Abstract: The invention relates to a hydraulic circuit (20) for public works vehicles. The circuit comprises: a pump (21) which is driven by a heat engine (22) using a load sensing technique; a hydraulic motor (10) which is used to move one part of the vehicle (8) and a set of hydraulic actuators (12-14); at least one distributor (29) which supplies the hydraulic actuators (12-13) in a controlled manner; and a device (45) for cooling the fluid circulating through the circuit. The inventive circuit is characterised in that it comprises: a pressure-reducing device (33) which is connected to the outlet of the pump (21) and which delivers a first pressure level, said device (33) being connected to the feed port (34) of the hydraulic motor (10); and an assembly which connects a check valve (40) and a calibrated orifice (41) in parallel, said assembly being connected downstream of the feed port (34) of the hydraulic motor and the return line (36) of the distributor (29) and upstream of the cooling device (45).

Abstract: A construction equipment machine has a lower frame and an upper frame rotatably connected, the machine having at least one hydraulic pilot circuit comprising a primary hydraulic pilot line running from the upper frame to the lower frame through a rotary joint for controlling the operation of at least one hydraulic device located on the lower frame, including: a pressure regulating system capable of setting in the pilot circuit a pilot pressure having a value; a hydraulic pressure controlled selecting system which is located on the lower frame and is fed by the primary hydraulic pilot line, at least two independent secondary pilot lines located downstream of the pressure controlled selecting system, and wherein said hydraulic pressure controlled selecting system is capable of selectively and independently supply or not supply pressurized fluid to the independent secondary pilot lines, responsive to the value of the pilot pressure.

Abstract: The invention relates to a hydraulic circuit (20) for public works vehicles. The circuit comprises: a pump (21) which is driven by a heat engine (22) using a load sensing technique; a hydraulic motor (10) which is used to move one part of the vehicle (8) and a set of hydraulic actuators (12-14); at least one distributor (29) which supplies the hydraulic actuators (12-13) in a controlled manner; and a device (45) for cooling the fluid circulating through the circuit. The inventive circuit is characterised in that it comprises: a pressure-reducing device (33) which is connected to the outlet of the pump (21) and which delivers a first pressure level, said device (33) being connected to the feed port (34) of the hydraulic motor (10); and an assembly which connects a check valve (40) and a calibrated orifice (41) in parallel, said assembly being connected downstream of the feed port (34) of the hydraulic motor and the return line (36) of the distributor (29) and upstream of the cooling device (45).