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:
Mar. 07, 1995
Filed:
Aug. 24, 1993
Applicant:
Inventors:
Roger P Johns, Terrace Mustang, OK (US);
Gary Portwood, Katy, TX (US);
Gilbert S Tyner, Mission Viejo, CA (US);
Charles R Muren, Humble, TX (US);
Assignee:
Smith International, Inc., Houston, TX (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
E21B / ;
U.S. Cl.
CPC ...
175332 ; 175403 ;
Abstract
A roller cone drill bit is disclosed that leaves uncut a substantial formation core having a diameter from 10% to 25% of the bit gage diameter. The bit is designed to have normal size bearings, cone shell thickness and cutter protrusion to allow the use of standard drilling weights and RPM, thereby achieving a significant increase in drilling rate. When drilling abrasive formations, ultra hard cutting teeth are used in the cone apex to maintain the core diameter.