Patent ID: 6065288
Filing Date: 2000-05-23
Classification: F15B,Y10T

Abstract:
A control valve comprising:a spool valve housing having a cylindrical bore;in said housing, a source port;in said housing, a poppet check valve element;in said bore, a spool valve element mechanically connected to said poppet valve element, the side of said spool valve element opposite said stem being open to said source port, movement of said spool valve element responsive to pressure at said source port being operative to open said poppet valve element, said spool valve element having an interior chamber,said spool valve housing and said spool valve element forming:a throttle port which is opened to said interior chamber by displacement of said spool valve element opening said poppet valve anda source drain port which is opened to said source port by displacement of said spool valve element opening said throttle port; andin said spool valve element, a check valve permitting flow from said interior chamber to said source port;aligned with said spool valve element, a piston adapted to engage said spool valve element in a direction aiding opening of said poppet valve); anda port in said housing providing fluid pressure access to the side of said piston opposite said spool valve element.