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:
Nov. 09, 1982
Filed:
Dec. 22, 1980
George A Kappenhagen, Stroud Township, Monroe County, PA (US);
Westinghouse Electric Corp., Pittsburgh, PA (US);
Abstract
A hydraulic system having a single acting, mult-stage, synchronous hydraulic jack having a trapped oil space which provides the required synchronism. The hydraulic system additionally includes a first external pump in fluid flow communication with an oil space disposed between the outer cylinder and an intermediate section, and a second external pump disposed in fluid flow communication with the trapped oil space between the intermediate section and an inner plunger section. Oil leakage from the trapped oil space is detected when the sections are retracted. The next time the sections are to be extended following such detection, both pumps are automatically started, with the second pump being deactivated when the trapped oil space has been replenished.