Electric power tool
US9154062B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 7, 2012 |
| Grant date | Oct 6, 2015 |
| Priority date | — |
| Expiry date | Jun 17, 2032 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB25F5/00
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
An electric power tool is provided with a three-phase brushless motor that drives a tool and a motor driver that drives the three-phase brushless motor with square voltage waves. The motor driver is able to set a conduction angle to a value that is equal to or more than 130 degrees but not more than 180 degrees, and especially to change the conduction angle among at least two values that are equal to or more than 130 degrees but not more than 180 degrees. In this configuration, it may be preferable that the conduction angle is set to a larger value as a load applied to the tool becomes smaller. On the other hand, it may be also preferable that the conduction angle is set to a larger value as a load applied to the tool becomes smaller.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.