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:
Nov. 29, 2022
Filed:
Oct. 27, 2017
Koki Holdings Co., Ltd., Tokyo, JP;
Takuya Yoshinari, Ibaraki, JP;
Kazutaka Iwata, Ibaraki, JP;
Koki Holdings Co., Ltd., Tokyo, JP;
Abstract
An electric tool capable of achieving inhibition of reaction due to braking in good balance with inhibition of voltage jumping due to regenerated energy is provided. A grinder () is provided with a motor (), an inverter circuit () for supplying electric current to the motor (), and a controller () for controlling the inverter circuit (). When generating an electric braking force on a motor (), the rotation speed of which exceeds a specified rotation speed, the controller () performs a first braking control of continuously turning on lower arm-side switching elements (Q-Q) of the inverter circuit (), after which the controller performs a second braking control of repeatedly turning on and off the lower arm-side switching elements (Q-Q).