Power fastening tool
US7155986B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 13, 2004 |
| Grant date | Jan 2, 2007 |
| Priority date | — |
| Expiry date | Feb 1, 2025 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB25B23/1475
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
In a power fastening tool for fastening a fastening member such as a screw or a fastening member, malfunction that driving of a motor is stopped before the fastening member is fastened completely can be prevented. A fastening judger judges that the fastening operation is completed when a value of an estimated torque T for fastening the fastening member becomes larger than a predetermined lower limit value T1 previously set by a user and a value of a torque variation ratio ΔΔT varies from positive to negative. Thus, it is possible to prevent malfunction for stopping driving of a motor even when the value of the torque variation ratio ΔΔT varies from positive to negative due to trouble before the vale of the estimated torque T becomes larger than the lower limit value T1.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.