The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 19, 1980
Filed:
Jan. 23, 1979
Clifford M Peters, Longview, TX (US);
W-K-M Wellhead Systems, Inc., Shreveport, LA (US);
Abstract
An improved pilot valve mechanism for controlling the flow of a pressure medium responsive to predetermined variations in a pressurized system. The pilot valve mechanism is constructed in such manner that a plurality of pilot valves may be connected in an assembly and may be operative to shut down operation of a flow system responsive to sensing of pressures that are above or below a predetermined range of operating pressure. Each of the valves may include a shuttle valve mechanism capable of interrupting fluid communication between the inlet and outlet of the pilot valve mechanism or between the outlet and vent thereof, depending upon the position of a shuttle valve actuating piston that is proportionally movable responsive to variations in the pressure that is sensed by the pilot valve mechanism. Movement of the shuttle valve actuating piston and the shuttle valve are controlled by an urging means that may be adjustably preset for a particular high or low pressure. The shuttle valve incorporates annular peripheral seal that is retained in assembly with the shuttle valve and engagable with and movable partly beyond annular sealing edges defined within the valve body of the valve assembly in order to control fluid communication between the various ports. Slight movement of the shuttle valve peripheral seal away from the annular sealing edges affords substantial cross-sectional flow area for large volume flow, thus providing for rapid pressure responsive actuation. Utilization of sealing elements having low friction characteristics and utilization of a low friction spring for urging the shuttle valve and piston between operative positions thereof, facilitates accurate operation of the pilot valve mechanism at relatively narrow pressure differentials.