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:
Dec. 08, 1981
Filed:
Sep. 20, 1979
John W Erickson, Huntington Beach, CA (US);
Harold L Petrie, Sieria Madre, CA (US);
F Barton Brown, La Crescenta, CA (US);
Herbert L Johnson, Los Angeles, CA (US);
Kobe, Inc., Commerce, CA (US);
Abstract
This invention effects a significant reduction in leakage along a piston reciprocating in a cylinder and having a high fluid pressure differential existing between one end of the piston and the other. A large number of closely spaced, annular grooves are provided on the periphery of the piston and the clearance between the non-grooved piston diameter and the interior wall of the cylinder is maintained at a value significantly larger than that commonly employed between a smooth cylindrical shaft and a cylindrical interior sealing surface. The employment of such unexpectedly large clearance not only provides reduced fluid leakage for lighter density fluids when the equipment is relatively new, but the leakage becomes substantially less than that encountered in a smooth surface bearing construction as the piston and cylinder surfaces wear and increase the clearance.