Power tools
US6771043B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 8, 2002 |
| Grant date | Aug 3, 2004 |
| Priority date | — |
| Expiry date | Jun 14, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02J7/0031
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Battery-powered tools may include battery 1 or battery pack BP and a drive source (e.g., motor M) for generating power using current supplied from the battery. A switch 3 may electrically connect the battery to the drive source. A voltage detector may detect the output battery voltage of the battery. Further, a processor 60, 210, a comparator 5 or another similar device preferably determines when a difference between (1) a first battery voltage detected at a first predetermined time period after the switch is turned OFF and (2) a second battery voltage detected at a second predetermined time after the first predetermined time period exceeds a predetermined value. This information may be utilized to determine whether to warn an operator of the battery powered tool that further operation using the battery 1 or battery pack BP should be discontinued.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.