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.

Date of Patent:
Jul. 14, 2009

Filed:

May. 04, 2007
Applicants:

Olaf Koch, Kaufering, DE;

Karl-heinz Hofmann, Weil, DE;

Inventors:

Olaf Koch, Kaufering, DE;

Karl-Heinz Hofmann, Weil, DE;

Assignee:
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
E21B 10/43 (2006.01);
U.S. Cl.
CPC ...
Abstract

A solid hard material head for a percussion drilling tool rotatable about a rotational axis (A) in a rotational direction (ω), includes at least one main bit and at least one auxiliary bit (), circumferentially offset relative to the at least one main bit () and having an auxiliary cutting edge () formed, at least piecewise, as a circular arc section () spaced from the rotational axis (A) radially inwardly and inclined in a radial direction, and a straight outer section () extending radially outwardly with respect to the circular arc section () and inclined in the radial direction.


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