Anti-kickback power tool control
US4249117A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 1, 1979 |
| Grant date | Feb 3, 1981 |
| Priority date | — |
| Expiry date | May 1, 1999 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01P3/489
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
An impending kickback condition in the operation of a power tool or machine tool system is sensed and used to control or eliminate the kickback. The ability to sense an impending kickback condition can be used in all categories of power driven tools. The change in force applied to the power driven tool or other implement is monitored with a microcomputer by measuring the rate of change of current. If the current is increasing, the microcomputer compares the rate of change of current with a threshold value which may be either preset or computed by the microcomputer. If this threshold value is exceeded, an output control signal is generated by the microcomputer which inhibits the coupling of power to the tool or other implement and/or applies a brake to stop the tool or implement. In order for power to once again be coupled to the tool or implement, the start switch must be opened and then reclosed or some other signal provided by the operator or another predetermined condition must be fulfilled.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.