| 摘要 |
A selector valve for use with a resistance-welding pneumatic cylinder, the selector valve comprising a valve body (76), a valve member (74) moveable in the valve body, a first port (68) connected to a second port (70) by a first flow path defined by the valve member when said member is in a first position and connected by a second flow path defined by the valve member to a third port (72) when the valve member is in a second position, means (80, 86, 90) biasing the valve member towards the second position, the presence of pressure in the first flow path causing the valve member to move to the first position. |
