Patent ID: 6293180
Filing Date: 2001-09-25
Classification: F15B,Y10T

Abstract:
A fluid pressure control circuit, comprising:a pressurized fluid source;a directional control valve connected to said pressurized fluid source;a pair of speed controllers, each of which comprises:a pilot check valve having a first body which has a first fluid inlet/outlet port defined in an end thereof and a pilot port defined in an opposite end thereof;a flow control valve having a second body integral with said first body;a pipe joint having a third body which has a second fluid inlet/outlet port defined in an end thereof, said third body being integral with said second body;a flow adjustment member disposed in said flow control valve and extending into a fluid passage interconnecting said first fluid inlet/outlet port and said second fluid inlet/outlet port, for adjusting a rate of flow of a fluid under pressure in said fluid passage;a valve body disposed in said pilot check valve for opening a fluid passage interconnecting said first fluid inlet/outlet port and said second fluid inlet/outlet port in response to a pilot fluid pressure supplied from said pilot port; anda stem movably disposed in said first body and a valve seat fixedly disposed in said first body, wherein said valve body is slidably fitted over said stem, the arrangement being such that said stem and said valve body are integrally displaceable in response to the pilot fluid pressure supplied from said pilot port for unseating said valve body off said valve seat;a cylinder having respective ports, and respective fluid passages providing fluid communication between said respective ports and the first inlet/outlet ports of each of said pair of speed controllers;wherein a first fluid passage from said directional control valve branches for providing fluid communication between the pressurized fluid source and the second inlet/outlet port of one of said pair of speed controllers, while simultaneously providing fluid communication between the pressurized fluid source and the pilot port of another of said speed controllers, andwherein a second fluid passage from said directional control valve branches for providing fluid communication between the pressurized fluid source and the second inlet/outlet port of the other of said pair of speed controllers, while simultaneously providing fluid communication between the pressurized fluid source and the pilot port of said one of said speed controllers.