Patent ID: 6209565
Filing Date: 2001-04-03
Classification: F16K,Y10T

Abstract:
A pulse piloted cartridge valve comprising:a housing defining a piston chamber, a supply port, a vent port and a control port;a latching piston assembly having an upper stem and a head, said latching piston assembly slidably located in said piston chamber and movable between an open position and a closed position;a biasing mechanism to bias said latching piston assembly to the closed position, sealing said supply port from said control port;a pilot open piston slidably received on said upper stem of said latching piston assembly within said piston chamber, said pilot open piston defining a pilot open chamber above said pilot open piston, such that a pulse applied to said pilot open chamber moves the latching piston assembly downward to the open position;a first passageway within said latching piston assembly leading from the supply port to the piston chamber between the head of the latching piston assembly and the pilot open piston for applying pressure from the supply port when said latching piston assembly is in said open position to hold the latching piston assembly in said open position without continued application of pulse pressure to said pilot open chamber; anda poppet cavity communicating said control port, said vent port, said supply port and said first passageway, said poppet cavity blocking the supply port from the vent port while the latching piston assembly is in the open position;wherein if supply pressure from said supply port fails, said biasing mechanism forces said latching piston assembly back to the closed position.