Patent ID: 8800958

Claim:
A slow-acting ON/OFF valve comprising: an actuating member which actuates a valve body that comes into contact with and moves away from a valve seat to close and open a flow passage; a spring device which biases said actuating member in a valve-closing direction; a valve-opening pressure chamber which exerts a force in a valve-opening direction on said actuating member against said spring device; a manifold provided independently of said valve-opening pressure chamber; a pressure regulation valve which allows air to flow into said valve-opening pressure chamber from said manifold until pressure in said valve-opening pressure chamber reaches a predetermined reserve pressure, and which is closed upon said pressure in said valve-opening pressure chamber reaching said reserve pressure; a flow rate regulation valve which supplies air to said valve-opening pressure chamber from said manifold, in minute increments, after said pressure in said valve-opening pressure chamber reaches said reserve pressure, the moving speed of the valve body toward the valve opening direction being adjusted by an opening amount of the flow rate regulation valve; and an exhaust valve which discharges air in said valve-opening pressure chamber to said manifold upon pressure in said manifold dropping below said pressure in said valve-opening pressure chamber.