Variable speed trigger switch
US4737661A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 27, 1986 |
| Grant date | Apr 12, 1988 |
| Priority date | — |
| Expiry date | Oct 27, 2006 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01H9/52
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A variable speed trigger switch particularly adapted for use with electric power tools such as drills. The trigger switch features clam shell construction and a single vertically disposed circuit board thereby facilitating assembly and resulting in a low cost and compact unit. Wire connections are kept to a minimum through use of the circuit board in accordance with this invention having power contact resistance and wire terminal connectors formed directly on the board. The trigger switch includes a locking feature enabling the trigger switch to be locked at a desired position and further provides an adjustable detent which can be felt by the user during trigger retraction. The electronics package of the trigger switch employs an electronic motor speed control circuit which provides a combination of open loop and closed loop motor control.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.