| 摘要 |
The valve cartridge, for lockable non-return valves for gallery lining frame struts in mining, has a main piston (78) and a control piston (76). This is actuated by fluid fed through a transverse channel (50) in the casing (72) into an annular gap (64) between it and the wall of the piston mounting bore (60). An independent claim is included for a valve system, use in lockable non-return valves for gallery lining frame struts in mining, containing the cartridge. |
