Torque responsive motor shutoff for power tool
US3970151A · kind A · utility
19Cited by
4References
11Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Jul 3, 1975 |
| Grant date | Jul 20, 1976 |
| Priority date | — |
| Expiry date | Jul 3, 1995 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB25B23/145
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A pneumatic power tool for tightening threaded fasteners includes a planetary gear unit in which the ring gear is rotatable against the bias of a torsion coil spring to actuate a motor shutoff control valve at a predetermined torque reaction exerted on the ring gear. The torsion spring is in a substantially relaxed state during fastener rundown and before torque buildup on the fastener regardless of the torque setting at which motor shutoff is to occur. Adjustment of the motor shutoff torque setting is obtained by changing the positional relationship between a control valve pushrod and a cam surface on the ring gear member.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.