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. 05, 1980
Filed:
Nov. 06, 1978
Applicant:
Inventor:
Howard E Mitchell, Duncanville, TX (US);
Assignee:
Dresser Industries, Inc., Dallas, TX (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
E21B / ; E21C / ;
U.S. Cl.
CPC ...
175334 ; 175 53 ; 175385 ;
Abstract
A raise bit for enlarging a pilot hole into a larger diameter hole by disintegrating the earth formations that surround the pilot hole is provided with a cutter arrangement that provides a continuous angle bottom configuration in the range of 134.degree. to 60.degree..