Patent ID: 7055637

Claim:
An improved tilting device for tilting a cab of a vehicle between a driving position and a tilted position, which cab is resiliently supported on the chassis of the vehicle, which tilting device comprises: a reservoir for hydraulic fluid, a pump which is connected to the reservoir for delivering pressurized hydraulic fluid, a double-acting hydraulic tilting cylinder for tilting the cab, comprising a cylinder housing having a cylinder space in which a piston-piston rod assembly is moveable in a reciprocating manner, which piston-piston rod assembly, in the cylinder space, forms a pull chamber which, when hydraulic fluid is supplied to it, retracts the piston-piston rod assembly, and a pressure chamber which, when hydraulic fluid is supplied to it, extends the piston-piston rod assembly, an associated pull and pressure connection being provided for the pull and pressure chambers, respectively, a lost-motion passage, which extends between ports which open out into the cylinder space of the tilting cylinder, also being provided at the tilting cylinder, which ports are respectively in communication with the pressure chamber and the pull chamber if the piston of the piston-piston rod assembly is in a lost-motion range defined by the ports, the piston-piston rod assembly, within the said lost-motion range, being able to move up and down if the cab, which is in its driving position, executes spring movements, wherein the tilting device further comprises a system of lines, such that the pull connection and the pressure connection of the tilting cylinder are connectable as desired to the pump or the reservoir, which system of lines comprises at least one connecting line between the pump and the pressure connection of the tilting cylinder, for delivering pressurized liquid by the pump to the pressure connection, a reservoir line leading to the reservoir, which is connected to the relevant connecting line, and an associated reservoir valve for opening and closing the reservoir line being provided, wherein the improvement is that a flow restrictor is incorporated in the said connecting line between the pump and the pressure connection of the tilting cylinder, and in that the reservoir valve is designed—when fluid flows out of the pressure chamber via the pressure connection—to open the reservoir line under the influence of a pressure drop caused by said flow restrictor, and in that the reservoir valve is designed—when fluid flows in the direction from the pump to the pressure chamber—to close the reservoir line under the influence of a pressure drop caused by said flow restrictor.