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:
Feb. 07, 1984
Filed:
Nov. 26, 1982
Applicant:
Inventors:
Nareshchandra J Kar, Westminster, CA (US);
Rao R Nimmagadda, Fountain Valley, CA (US);
Assignee:
Smith International, Inc., Newport Beach, CA (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
E21B / ;
U.S. Cl.
CPC ...
384 94 ; 175371 ; 277 26 ; 277177 ;
Abstract
A resilient O-ring shaft seal for use in a rotary rock bit is described wherein the degree of squeeze imposed upon the O-ring seal is increased in one or more discrete steps, occurring as drilling conditions or bearing deterioration cause rising temperatures to be imposed on the seal. The squeeze is increased in discrete steps through a thermally related shape change in one or more nitinol, or the like, back up rings positioned adjacent to the packing ring seal housed within a seal gland. The seal gland is formed between a rock bit journal and a rock cutter cone rotatably mounted to the journal.