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:
Oct. 29, 1985
Filed:
Apr. 05, 1984
Applicant:
Inventors:
Gerhard Rumpp, Inning, DE;
Dieter Scholz, Unterpfaffenhofen, DE;
Assignee:
Hilti Aktiengesellschaft, Funstentum, LI;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
E21B / ;
U.S. Cl.
CPC ...
175394 ; 175323 ; 408226 ; 408230 ;
Abstract
A rock drill is formed of an axially elongated member made up of a cutting bit at one end followed by a helically grooved shaft and then ending in a shank. At least a portion of the groove, viewed in the axial direction of the member, has a stepped bottom providing groove sections of different depths. The depth of the groove section from the surface of the shaft decreases in the direction toward the shank. The groove sections with stepped bottom commence at a certain axial length from the cutting bit.