Patent ID: 6192937
Filing Date: 2001-02-27
Classification: F15B,Y10T

Abstract:
A pilot operated valve assembly comprising:a valve body having a pressurized air supply inlet port in communication with a source of pressurized air, and at least one cylinder passage;a main valve bore extending axially within said valve body and a main valve member including a spool valve having a pair of opposed valve heads disposed at either end of said spool valve, said opposed valve heads presenting a piston surface extending transversely relative to said main valve bore, said main valve member being movable between predetermined positions within said main valve bore to selectively direct pressurized air from said inlet port through said at least one cylinder passage;a pilot valve bore formed integrally within said valve body and extending parallel to and spaced a short distance from said main valve bore;a pair of short pilot cylinder ports spaced apart from one another and extending between said main valve bore and said pilot valve bore, said pilot cylinder ports communicating with said main valve bore immediately adjacent said opposed spool valve heads with each piston surface being aligned flush with a corresponding one of said pilot cylinder ports as viewed in cross-section to alternatingly direct fluid pressure against said valve heads thereby moving said spool valve between said predetermined positions; anda pilot valve member movable between predetermined positions within said pilot valve bore to selectively direct air from said pilot valve bore through alternating ones of said pilot cylinder ports to act upon said main valve member thereby moving said main valve member between said predetermined positions.