| 摘要 |
A combined electrical and fluid control switch is disclosed, comprising a casing, at least one operating carriage movable in the casing, and valve means in the casing and operable by the movement of the carriage. The valve means may comprise a valve wall along which a control member is movable. The valve wall is formed with at least one vacuum supply port and at least one vacuum utilization port. The control member includes a sealing member having first and second sealing dam enclosures which provide a double seal to prevent leakage between the atmosphere and the vacuum supply port as the control member is moved between a first position in which the support port and the utilization port are connected together, and a second position in which the utilization port is connected to the atmosphere. Each port preferably has a tapered portion at the intersection between the port and the valve wall.
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