Electronic control circuitry for a nutrunner
US4987806A · kind A · utility
24Cited by
2References
10Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Aug 15, 1990 |
| Grant date | Jan 29, 1991 |
| Priority date | — |
| Expiry date | Aug 15, 2010 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB25B23/147
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
Generally there is provided a nutrunner appliance for automatically driving a nut having an electrical motor, gearing, and a strain gauge to monitor the applied torque. The control system employs analog comparator circuits acting on analog signals from the strain gauge to determine the torque being applied. During operation, the comparator detects a predetermined torque and shifts the motor to a lower velocity to lower the inertia of the system. When the strain gauge output corresponds to the desired final torque, a braking action is applied to the motor to quickly terminate the applied torque.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.