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:
May. 21, 1985
Filed:
Apr. 28, 1983
Walter J Stinson, Houston, TX (US);
Larry J Phillips, Houston, TX (US);
General Signal Corporation, Stamford, CT (US);
Abstract
A control system for a valve actuator which is subject to oppositely directed displacement due to thermal expansion and spring forces has sensor switches which detect successively greater amounts of compression of a spring which compresses to accommodate thermal expansion of the valve, its stem and seat when the valve is seated in closed position. A position servomechanism which is responsive to the position of the stem and a control signal operates a motor for advancing and retracting the stem. Separate control devices, which are two way valves when the motor is a fluid motor and the servomechanism is a fluid operative servomechanism, are controlled by the sensor switches to stop the motor from overcompressing the spring when first position of the spring is reached and to operate the motor to retract the valve back to the first position when the second position is reached whereby to maintain a predetermined bias forcing the valve against the seat due to the spring forces in spite of thermal expansion of the valve, its seat and stem.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile