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:
Nov. 04, 2014
Filed:
Sep. 04, 2009
Kazuya Yanagida, Anpachi-gun, JP;
Koichiro Naruke, Anpachi-gun, JP;
Kazuya Yanagida, Anpachi-gun, JP;
Koichiro Naruke, Anpachi-gun, JP;
Mitsubishi Materials Corporation, Tokyo, JP;
Abstract
A guide portion prevents the drilling hole from curving due to a skipping rope phenomenon, and also prevents the inner wall face of the drilling hole from being damaged, so that its surface roughness can be improved. Chip evacuating flutesare formed in the periphery of a drill bodywhich has a stick shape and is rotatable on its axis O, from its front flanktoward the rear side. Cutting edgesA are formed along ridge lines where the front flanksintersect with wall facesA which are in the chip evacuating flutesand face in a drill rotational direction T. A cutting edge section, where the cutting edgesA are formed, is provided in the front side of the drill body. A cutting edge sectionhas an external diameter which is smaller toward the rear side in the axis O direction than the external diameter D at the cutting edgesA. A guide portionhas a maximum external diameter partA at the front periphery side, and is provided to the rear side of the cutting edge section An external diameter at the maximum external diameter partA is larger than the external diameter at the rear of the cutting edge section, and is smaller than or equal to the external diameter D at the cutting edgesA. The maximum external diameter partA of the guide portionshows a smooth convex curve shape in a rotatory figure obtained by rotating it on the axis O.