Electric power machine with protection against overspeed
US4516045A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 14, 1984 |
| Grant date | May 7, 1985 |
| Priority date | — |
| Expiry date | May 14, 2004 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01H35/10
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An electric power machine, particularly an angle grinding tool is provided with a centrifugal overspeed protecting device including a fly weight in the form of a severing blade which interrupts a power supply conduit when the rotary speed of the machine is excessive. The protective device includes a cylindrical housing attached face to face to the shaft of the electric motor. The severing blade is in the form of a quadrangular frame defining a center opening. The cylindrical housing is provided with a diametric through bore of a rectangular cross-section matching the frame-like severing blade. A blind bore of a circular cross-section is coaxially superposed on the rectangular through bore and its upper part is formed with inner thread for receiving a setting screw. A helical tensioning spring is inserted in the center opening of the frame-like severing blade and rests on the bottom of the blind bore to urge the centrifugal severing blade against the setting screw. When the rotary speed of the shaft and thus of the housing exceeds a predetermined value the severing blade is displaced by centrifugal force out of the rectangular through bore and severs a conduit in the power supply ci…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.