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:
Dec. 10, 2019
Filed:
Mar. 25, 2015
Hitachi Koki Co., Ltd., Tokyo, JP;
Nobuhiro Takano, Ibaraki, JP;
Kazutaka Iwata, Ibaraki, JP;
Toshiaki Koizumi, Ibaraki, JP;
Naoki Tadokoro, Ibaraki, JP;
Hiroshi Haga, Ibaraki, JP;
Shinichirou Satou, Ibaraki, JP;
KOKI HOLDINGS CO., LTD., Tokyo, JP;
Abstract
An electric tool including a motor configured to be driven by a PWM control of a semiconductor switching element by using a power supply, a power transmission mechanism configured to transmit a rotation of the motor to an end tool, and a controller configured to control a rotation of the motor by a duty ratio of a PWM signal, wherein the controller is configured to set the duty ratio to a reference duty ratio less than 100% when a voltage of the power supply applied to the electric tool is within a predetermined range including a rated voltage of the electric tool, and wherein the controller is configured to drive the motor by setting the duty ratio to be higher than the reference duty ratio when the voltage of the power supply applied to the electric tool is lower than the predetermined range.