| 摘要 |
PURPOSE:To enlarge the opening and closing strokes of a diaphragm type valve member and as well to enhance the durability of the latter while making it compact, by constituting an opening and closing mechanism for the diaphragm type valve member with a closed bellows-type expansible member. CONSTITUTION:An opening and closing mechanism 6 is constituted such that a closed bellows type expansible member 9 connected at its upper and lower ends thereof with attaching members 7, 8, respectively, is attached to a supporting member 10, the lower attaching member 8 is connected to a valve rod 4 while a compressed spring 11 is disposed between the attaching member 8 and a valve box 2, and a pneumatic pressure supply device 5 is connected to a connector 12 fitted in the upper attaching member 7, through a pipe line 13. The number of folded parts in the above-mentioned bellows type expansible members is made large for enlarging the opening and closing strokes of the shut-off valve while making stress in the folded parts small, thereby the durability of the valve is enhanced. |
