Patent ID: 8607821

Claim:
A stack valve comprising: an unloading path connected to a hydraulic pump; a tank path connected to a tank; a first direction switching valve connected to the unloading path and controlling supply of a pressure fluid from the hydraulic pump to a first actuator; a pair of first supply and discharge paths connecting the first direction switching valve with the first actuator; a second direction switching valve connected to the unloading path at the downstream of the first direction switching valve and controlling supply of the pressure fluid from the hydraulic pump to a second actuator; a pair of second supply and discharge paths connecting the second direction switching valve with the second actuator; and a tank return path connecting the first direction switching valve with the tank path, wherein the pressure fluid returns from the first supply and discharge paths to the unloading path when the first actuator is activated, and the first direction switching valve has a changeover position at which the unloading path on the upstream of the first direction switching valve is connected with one of the first supply and discharge paths and the other one of the first supply and discharge path is connected with the unloading path on the downstream of the first direction switching valve and the tank return path.