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, 1991
Filed:
Jun. 09, 1989
Applicant:
Inventors:
Johann Lohmuller, Ravensburg, DE;
Klaus Dreps, Altshausen, DE;
Assignee:
DreBo Werkzeugfabrik GmbH, Altshausen, DE;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
E21B / ;
U.S. Cl.
CPC ...
175398 ; 175399 ; 175406 ; 175408 ;
Abstract
A drill bit for producing an undercut. The drill bit includes a shaft and a cutting edge that is disposed asymmetrically radially beyond the shaft in a front end portion of the drill bit. A planar guide surface is provided on a conical end face of the drill bit. This guide surface is disposed radially opposite the cutting edge. The guide surface terminates at a concentric tip of the drill bit.