Valve arrangement for use with a hydraulic accumulator

A valve arrangement for connection of a hydraulic pressure accumulator with a hydraulic machine and a reservoir tank, said valve arrangement comprising:

• a leak-free shutoff valve having one port connected to a pressure accumulator and a second port connected to a hydraulic machine,
• said shutoff valve including:
• an actuator cylinder and an actuator piston slidably movable in leak-proof manner in said cylinder by a control pressure and a valve member on said piston pressed against a valve seat of said shutoff valve when the piston is acted upon by the control pressure,
• a shuttle valve including control lines connecting the shuttle valve with each of the two ports of the shutoff valve and connecting the shuttle valve with a supply line for communicating said control pressure to said actuator cylinder, said shuttle valve including a displaceable valve member which moves in response to the control pressure at the two ports of said shuttle valve to connect said supply line with that one of the two ports which is at the higher control pressure than at said other port, and a leak-proof remote-controlled actuator valve in said supply line in one operative position for controlling the control pressure from said shuttle valve to said actuator piston for closing the shutoff valve , and
• said remote-controlled valve being constructed to assume another operative position in which it interrupts and by passes the connection between the shuttle valve and the cylinder to allow the control pressure to exhaust through said remote-controlled valve which opens a relief connection between the cylinder and the tank.