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:
Jul. 22, 2003
Filed:
Nov. 08, 2000
Toru Mizuno, Fukushima-ken, JP;
Ikuo Hattori, Mitsukaido, JP;
Akihiko Sugama, Koriyama, JP;
Toshikatsu Matsuya, Tendo, JP;
Yoshiaki Ise, Tendo, JP;
Other;
Abstract
A core drill having a shank and a cup shaped base metal section constructed of a disk shaped top wall and a cylindrical side wall provided on a fore-end of the shank. A grinding stone portion is mounted on an outer end part of the base metal section, with abrasive grains fixed to the outer end part of the base metal section. Abrasive grain layers are formed in a spiral pattern on inner and outer side surfaces of the cylindrical side wall of the base metal section, with abrasive grains fixed to the inner and outer side surfaces of the cylindrical side wall thereof. When the grinding stone portion is put into rotational contact with a workpiece, the workpiece is ground through to form a circle hole in section leaving a cylindrical core therein.