Patent ID: 9689139
Date: 2017-06-27
CPC Classifications: E02F,Y10T

Claim:
1. A quick coupler comprising a coupling receptacle for receiving a first locking part and a locking receptacle for receiving a second locking part, wherein to the coupling receptacle a securing element is associated for at least one of catching and securing the first locking part in the coupling receptacle, and to the locking receptacle a locking element is associated for locking the second locking part in the locking receptacle, wherein the locking element and the securing element are actuatable by a common pressure circuit that includes an unlocking pressure port and a locking pressure port, wherein the securing element is actuable by a double-acting, reversible actuator and is hydraulically movable into an opening position as well as into a locking position by means of applying pressure medium from the common pressure circuit, wherein at least a locking chamber and an unlocking chamber of the actuator are pressurizable via a valve arrangement in dependency of a pressure level at at least one of the unlocking and locking pressure ports of the common pressure circuit; wherein the locking and unlocking pressure ports are selectively connectable with at least one of a pressure source and a return line via valve means, wherein a pressure switching valve of the valve arrangement opens upon at least one of reaching and exceeding a predetermined first pressure and is connected with the unlocking pressure port, and the valve means of the pressure circuit includes pressure control means for selectively controlling the pressure applied at the unlocking pressure port to a second pressure greater than the first pressure, and to a third pressure smaller than the first pressure; and wherein the pressure control means includes a pressure reducing valve for reducing the second pressure to the third pressure and a secondary switching valve provided upstream of the pressure reducing valve, which secondary switching valve in a first switching position applies an input pressure to the pressure reducing valve and in a second switching position applies the input pressure bypassing the pressure reducing valve to the unlocking pressure port.