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:
Sep. 14, 1993
Filed:
Dec. 02, 1992
Russell E Robertson, Ashland, OH (US);
The Shafer Valve Company, Mansfield, OH (US);
Abstract
A hydraulic pipeline valve operating system (10) includes a tank (12) which holds a quantity of unpressurized hydraulic fluid. A pump (14) provides that fluid under pressure to a valve actuator (11). The valve actuator has an actuator cylinder (40) having a piston (42) which is operatively connected to the pipeline valve (28). The fluid under pressure moves the piston (42) of the cylinder (40) to compress a spring (35) to open the valve (28). When the piston (42) of the cylinder (40) ceases movement, continued pumping moves a piston (53), of a smaller diameter than the piston (42), which also acts against the spring (35). An indicator rod (60) gives a visual indication of the position of the piston (53) and when it is at approximately its midstroke location, pumping of the fluid is terminated and the actuator (11) is set. Should ambient temperature conditions change, the piston (53) moves to accommodate such changes thereby leaving the piston (42) unaffected. When a pressure sensing valve (22) senses a predetermined pressure change in the fluid in the pipeline, a dump valve (23) is opened permitting the pressurized fluid in the system (10) to be transferred back to the tank (12). The spring (35) can thus move the piston (42) to close the pipeline valve (28).