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:
Jun. 20, 1989
Filed:
Jun. 24, 1987
Applicant:
Inventor:
Werner Kleine, Achim, DE;
Assignee:
Gebruder Heller GmbH. Werkzeugfabrik, Achim-Uphusen, DE;
Primary Examiner:
Int. Cl.
CPC ...
B23B / ; B23B / ;
U.S. Cl.
CPC ...
408226 ; 279 60 ; 279123 ; 279 19 ; 408240 ;
Abstract
The invention contemplates an improved drill-bit construction wherein the shank by which the bit is clamped is characterized by (a) three angularly spaced grooves which are continuous over their entire length of engageability to the jaws of a multi-jaw chuck, (b) at least one of the grooves being closed at its rear end, (c) the rear end of the closed-end groove is at no greater offset than 5-mm from the rear end of the bit, and (d) the diameter of the cutting part of the bit shank is greater than the diameter of the clamping part of the shank, to an extent which at most results from shaped formation of the chip-removal groove.