摘要 |
A fluid control valve for connection between a positive fluid pressure source, a negative fluid pressure source and a device to be connected alternately to the pressure sources, comprising a body having ports for connection to the fluid pressure sources and the device, and a rotary member rotatable with respect to the body and adapted selectively to interconnect the ports, whereby the rotary member is operable on rotation in a single sense to connect alternately the positive fluid pressure source and the negative fluid pressure source to the device. |