| 摘要 |
PURPOSE:To facilitate the restoration operation to the opened valve state by smoothly pushing-down a valve piece free from tilt. CONSTITUTION:In order to open a valve, an operating port 50 is opened by talking-off a cap 51. When an operating shaft 39 is revolved against the retaining strength of a spring 46, a returning cam 41 is turning-shifts in a gas inflow port. Therefore, the cam surface 42 of the returning cam 41 contacts with the center part of the upper surface of a valve piece 25, namely with the axis center of a supporting disc 27. When the returning cam 41 is further turning- shifted, the valve piece 25 is pushed-down against the retaining strength of a spring 29, and a plunger 33 is separated form a valve seat 22 and attracted onto a magnet 35. Therefore, the valve piece 25 is kept in the valve opened state. |
