Patent ID: 6427721
Filing Date: 2002-08-06
Classification: F15B,Y10T

Abstract:
Hydraulic valve arrangement with locking function, with a control valve, which in two operating positions connects one motor connection with a pump connection and a second motor connection with a tank connection and vice versa, and in a locking position separates both motor connections from pump and tank connection, and with two lock valves, each connected between the control valve and one of the motor connections, wherein for each lock valve a pressure release valve is provided, whose operating member is loadable in the closing direction by a first chamber pressure and an additional force acting in a first chamber and in the opening direction by a control pressure acting in a second chamber, and that the control pressure in dependence of the position of the control valve has a lower value, which is equal to the first chamber pressure, and an upper value, which exceeds the first chamber value by such a value that the oppositely acting closing force is overcome.