| 摘要 |
PURPOSE:To enable to smoothly operate an operating plate retaining a pressure element, by a method wherein a recessed groove provided in a back surface of a valve plate is constituted of a groove shaped indented part and a slant surface part extended from an intermediate depth position of a front edge of the indented part while becoming gradually shallower and connected to the back surface of the valve plate. CONSTITUTION:An operating plate 11 retains the pressure is element 18 between a groove 15 formed in a valve plate 7 and a groove 16 formed in a back plate 17, and when it is moved forward by a manual operation, the tip of an engaging member 8 energized by a leaf spring 13 comes into contact with an engaging wall 9 of a valve box 6 before the valve plate 7 reaches a position faced to a seat surface. When the plate 11 is further moved forward, the engaging member 8 is retracted relatively to the valve plate 7, a pin 22 comes into contact with the front end of a penetrating hole 8a, and the forward movement of the valve plate 7 is stopped. When the plate 11 is further forwardly moved, the pressure element 18 is separated from the grooves 15, 16 and rides on an upper surface 17a of the back plate 17 and the back surface 7c of the valve plate 7, and an O-ring 7b fitted to the valve plate 7 comes into close contact with a sealing surface 4a, thereby closing a passage 2. |
