| 摘要 |
A first normally open solenoid valve "A" is connected to passageway (32). A second normally open solenoid valve "B" is connected to a passageway (36). A latching valve (24) includes a valve spool chamber (26) and a valve spool (50) within the chamber. An air-delivery conduit (20) delivers pressurized air to both a first passageway (32) and a second passageway (36). Passageway (32) is connected to one end of the valve spool chamber (26). Passageway (36) is connected to the opposite end of the valve spool chamber (26). The valve spool (50) has two positions. In the first position, passageway (32) is connected with a passageway (40) that extends to an air-operated device (44). Flow through the valve (24) to and from passageway (36) is blocked. In the second position, flow from passageway (32) to passageway (40) is blocked. Also, flow through the valve (24) to and from passageway (36) is blocked. Air in the air-operated device is vented through passageway (40), the path (42), valve spool groove (56) and passageway (46) to a vent avenue (48).
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