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:
Apr. 28, 1981
Filed:
Sep. 10, 1979
Jack T Gregory, San Anselmo, CA (US);
Other;
Abstract
A hydraulic tool comprising a cylinder which is open at one end with a piston extending partially therein, but having a substantial portion extending outside. A lateral bore through the extending portion accommodates intake and exhaust check valves, but the bore is sealed off between them, forming an inlet chamber. Surrounding the inlet and exhaust ports and sealed at its opposite ends to the piston and cylinder, respectively, is a flexible, extendable sleeve forming an annular reservoir. A transfer duct extends from the inlet chamber to a pressure chamber formed between two seals around the piston, and a longitudinal bore opens into the inlet chamber from the extending end of the piston to slidably accommodate a manually-operated pump plunger.