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. 05, 1988
Filed:
Oct. 24, 1986
Jack T Gregory, Penngrove, CA (US);
The Gregory Company, Menlo Park, CA (US);
Abstract
The hydraulic tool of this invention includes a pressure chamber into which a fluid is pumped. A pump chamber has an inlet port and outlet port at opposite ends thereof and a pump plunger extends into the chamber with an annular space around it. An annular shoulder is provided on either the chamber or the plunger and a seal ring or sleeve fits slidably on the other component to seal against the shoulder. A spring biases the seal ring against the shoulder, and when the pump is extended to force fluid out the outlet port, the pressure in the chamber augments the spring force. Then, when the rod is retracted to create a void, fluid in the reservoir forces the seal ring or sleeve away from the seat surface to enter the inlet port.