Electric power tool
US8198839B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 4, 2007 |
| Grant date | Jun 12, 2012 |
| Priority date | — |
| Expiry date | Jul 22, 2029 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S388/937
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
An electric power tool “A” operates a working part 5 by repeating rotation of a motor 4 in a normal direction and in a reverse direction one or more times. The motor 4 includes a brushless motor. Sensors H for detecting a position of a rotor 15 are provided on the motor 4 so as to be advanced by an electrical angle of 30°±θ° from an intermediate position between respective stator teeth 16 in a direction of the normal rotation of the rotor 15. A control part 20 for controlling the rotation of the motor 4 controls a driving signal of the motor 4 based on the results of detection by the sensors H. Moreover, the control part 20 selects a detection signal of the sensors H so that relation between the rotor 15 and the detection signal of the sensors H is equivalent in either of the normal rotation and the reverse rotation of the rotor 15.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.