PILOT OPERATED PNEUMATIC VALVE

摘要

A pilot operated valve assembly (10) including a valve body (12) having a pressurized air supply inlet port (28) in communication with a source of pressurized air and at least one cylinder passage (30, 32). A main valve bore (34) extends axially within the valve body (12) and a main valve member (44) is movable between predetermined positions within the main valve bore (34) to selectively direct pressurized air from the inlet port (28) through at least one cylinder passage (30, 32). A pilot valve bore (122) is formed within the main valve member (44) and extends coaxially relative to the main valve bore (34). A pair of short pilot cylinder ports (136, 138) spaced apart from one another extend between the main valve bore (34) and the pilot valve bore (122). A pilot valve member (140) is movable between predetermined positions within the pilot valve bore (122) to selectively direct air from the pilot valve bore (122) through alternating ones of the pilot cylinder ports (136, 138) to act upon the main valve member (44) thereby moving the main valve member (44) between predetermined positions.