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:
Sep. 01, 1998
Filed:
Feb. 12, 1997
Masaaki Jindai, Itami, JP;
Jun Okamoto, Itami, JP;
Sumitomo Electric Industries, Ltd., Osaka, JP;
Abstract
A drill capable of drilling a deep hole while keeping high chip discharging ability and having a helical flute whose width and helix angle will not change even after the cutting edges have been regenerated by regrinding. The drill has a tip portion formed with a helical flute having a constant width and helix angle, a rear portion formed with a helical flute which are greater in width and smaller in helix angle than the helical flute formed in the tip portion, and a middle portion provided between the tip portion and rear portion and formed with a helical flute smoothly connecting with the helical flutes of the tip portion and rear portion and having a gradually increasing width and a gradually decreasing helix angle from the tip portion toward the rear portion.