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:
Oct. 04, 1983
Filed:
Aug. 17, 1981
Applicant:
Inventor:
Osamu Nakamura, Tokyo, JP;
Assignee:
Tsukamoto Seiki Co., Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
E21B / ;
U.S. Cl.
CPC ...
175228 ; 384 93 ; 138 31 ;
Abstract
A pressure compensator installed in the bit body of a rotary earth boring tool to lubricate the bearing surfaces of a rotary cutter and to effect a liquid seal. In order to reduce the number of component parts and to enhance durability, the pressure compensator includes a rubber diaphragm interposed between upper and lower capsule halves that form a spherical space.