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:
May. 27, 2014
Filed:
Mar. 09, 2010
Manabu Saito, Tokyo, JP;
Tatsuo Nakahata, Tokyo, JP;
Hideharu Takahashi, Tokyo, JP;
Junji Tsuchiya, Tokyo, JP;
Eiji Hashimoto, Chiba, JP;
Hirofumi Higashiwaki, Mie, JP;
Manabu Saito, Tokyo, JP;
Tatsuo Nakahata, Tokyo, JP;
Hideharu Takahashi, Tokyo, JP;
Junji Tsuchiya, Tokyo, JP;
Eiji Hashimoto, Chiba, JP;
Hirofumi Higashiwaki, Mie, JP;
Fuji Jukogyo Kabushiki Kaisha, Tokyo, JP;
Makotoloy Co., Ltd., Osaka, JP;
Abstract
A drill includes a pair of main cutting edges extending from a distal portion of the drill to a position close to a proximal end of the drill to entirely define a two-edge configuration, and a pair of auxiliary cutting edges extending between positions at the distal and proximal sides of a maximum diameter position to partly define a four-edge configuration. A ridgeline of each auxiliary cutting edge is located within an angle smaller than 90° from a ridgeline of the corresponding main cutting edge toward the rear in a rotation direction of the drill. The point angle of the auxiliary cutting edges increases at a higher rate than the point angle of the main cutting edges in a predetermined range from the maximum diameter position toward a distal end of the drill.