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:
Apr. 01, 2014
Filed:
Jan. 19, 2010
Yoshikazu Kawano, Ibaraki, JP;
Nobihiro Takano, Ibaraki, JP;
Eiji Nakayama, Ibaraki, JP;
Kenro Ishimaru, Ibaraki, JP;
Kazumi Tanaka, Ibaraki, JP;
Masahiro Isono, Ibaraki, JP;
Yoshikazu Kawano, Ibaraki, JP;
Nobihiro Takano, Ibaraki, JP;
Eiji Nakayama, Ibaraki, JP;
Kenro Ishimaru, Ibaraki, JP;
Kazumi Tanaka, Ibaraki, JP;
Masahiro Isono, Ibaraki, JP;
Hitachi Koki Co., Ltd., Tokyo, JP;
Abstract
According to an aspect of the present invention, there is provided a power tool including: a motor; a switching device that switches over, in response to a conduction angle thereof, an AC voltage to be applied to the motor; a rotation speed setting unit that sets a target rotation speed of the motor; a rotation speed detection unit that detects an actual rotation speed of the motor; and a controller that determines the conduction angle by comparing the actual rotation speed with the target rotation speed and that controls the switching device by use of the conduction angle based on a maximum conduction angle, the maximum conduction angle being set in accordance with the target rotation speed.