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. 13, 1990
Filed:
Dec. 16, 1988
Applicant:
Inventors:
James H Cobbs, Tulsa, OK (US);
David C Cobbs, Glenpool, OK (US);
Assignee:
Other;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
E21B / ; E21B / ;
U.S. Cl.
CPC ...
175374 ; 175360 ; 175361 ; 175353 ;
Abstract
A drilling member for use in a drilling system, such as for drilling a large diameter subterranean hole or for removing rock at the earth's surface, in which the system employs a cutting head rotated about an axis and mounted for movement into a rock face, the cutting head having a plurality of drilling members, each of which has a truncated conical external surface rotated about the conical axis thereof, and a plurality of spaced-apart rows of indentors secured to the drilling member conical surface, the indentors being adapted to penetrate into the rock face a distance P, and wherein the indentors are spaced a distance not greater than 7 P apart.