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US 5,174,544 AGranted
Normally closed pilot operated bi-directional poppet valve
AssigneeDelta Power Hydraulic Co.
InventorFaraidoon Emanie
Life of this patent
Estimating the term…
Abstract
A normally closed pilot operated bi-directional poppet valve for controlling flow between first and second valve ports. When the pilot valve is closed, pressure is applied from whichever port is at the higher pressure to the poppet in a manner to hold the poppet closed. When the pilot valve is open, pressure is vented to whichever port is at the lower pressure in a manner to allow the poppet to open.
Claims19
A normally closed pilot operated bi-directional poppet valve comprising:
- (a) valve casing means defining a valve bore, a valve chamber at one end of the valve bore and a first pressure chamber communicating with an end of the valve bore remote from the valve chamber;
- (b) the casing means having first and second valve ports communicating with the valve chamber and a valve seat coaxial with the valve bore and having a cross-sectional area smaller than the cross-sectional area of the valve bore;
- (c) an elongated valve member including an intermediate portion slidable in the bore;
- a reduced first end portion extending from a first end of the intermediate portion and having a distal end adapted for engagement with the valve seat to shut-off flow between the first and second ports;
- a reduced second end portion extending from a second end of the intermediate portion and having a distal end exposed to fluid pressure in said first chamber;
- (d) a sleeve member slidable in the valve bore and slidably engaging said second end portion of the valve member for movement relative thereto between a forward position engaging said intermediate portion and a retracted position engaging an abutment on the casing means, the valve member and sleeve member define a second pressure chamber in the valve bore between the intermediate portion and one end of the sleeve member, the other end of the sleeve member being exposed to fluid pressure in said first pressure chamber;
- (e) a pilot valve passage means for communicating with said first pressure chamber and with said second pressure chamber, pilot valve means for controlling flow through said pilot valve passage means, means yieldably urging the pilot valve to a closed position closing the pilot valve passage means, and solenoid actuator means for actuating the pilot valve means to an open position;
- (f) first passage means communicating said first port with said second pressure chamber, said first passage means having first flow restrictor means therein and first check valve means operative to by-pass said first flow restrictor means when the pressure at the second pressure chamber is greater than the pressure at said first port;
- (g) second passage means communicating said second port with said first pressure chamber, said second passage means having second flow restrictor means therein and second check valve means operative to by-pass said second flow restrictor means when the pressure in the first chamber is greater than the pressure at said second port.
6 more elements
A normally closed pilot operated bi-directional poppet valve comprising:
- (a) valve casing means defining a valve bore having a cross-sectional area Al, a valve chamber at one end of the valve bore and a first pressure chamber communicating with an end of the valve bore remote from the valve chamber;
- (b) the valve casing means having first and second valve ports communicating with the valve chamber and a valve seat coaxial with the valve bore and the valve seat having a cross-sectional area smaller than the cross-sectional area of the valve bore;
- (c) an elongated valve member including an intermediate portion slidable in the bore;
- a reduced first end portion extending from a first end of the intermediate portion and having a distal end adapted for engagement with the valve seat to shut-off flow between the first and second ports;
- a reduced second end portion extending from a second end of the intermediate portion and having a distal end exposed to fluid pressure in said first chamber, the valve member, when closed, having a net forward facing seat area A2 exposed to fluid pressure at the first port;
- a net forward facing differential area A3 exposed to fluid pressure at the second port;
- a net rearward facing stem area A4 exposed to fluid pressure in the first pressure chamber and net rearward facing differential area A5 exposed to fluid pressure in the second pressure chamber,
- (d) a sleeve member slidable in the valve bore and slidably engaging said second end portion for movement relative thereto between a forward position engaging said intermediate portion and a retracted position engaging an abutment on the casing means, the valve member and sleeve member defining a second pressure chamber in the valve bore between the intermediate portion and one end of the sleeve member, the other end of the sleeve member having a net rearward facing area A6 exposed to fluid pressure in said first pressure chamber;
- (e) pilot valve passage means including a pilot valve port for communicating with said first pressure chamber and with said second pressure chamber, pilot valve member for controlling flow through said pilot valve port, spring means yieldably urging the pilot valve member to a closed position closing the pilot valve port, and solenoid actuator means for actuating the pilot valve member to an open position;
- (f) first passage means communicating said first port with said second pressure chamber, said first passage means having first flow restrictor means therein and first check valve means operative to by-pass said first flow restrictor means when the pressure at the second pressure chamber is greater than the pressure at said first port;
- (g) second passage means communicating said second port with said first pressure chamber, said second passage means having second flow restrictor means therein and second check valve means operative to by-pass said second flow-restrictor means when the pressure in the first chamber is greater than the pressure at said second port,
- (h) said sleeve member being movable to said forward position engaging the intermediate portion when the pressure in the first chamber is greater than the pressure in the second chamber.
9 more elements
Dependencies are inferred from the claim text.