Current protector
US3962664A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 25, 1975 |
| Grant date | Jun 8, 1976 |
| Priority date | — |
| Expiry date | Aug 25, 1995 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M1/745
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A current sensing, self-heating device for protecting equipment against abnormal current levels which is automatically resettable under mild overcurrent conditions and nonresettable under severe overcurrent conditions. The device comprises a thermostat metal assembly with a temperature compensating portion and an actuating portion which is placed adjacent a nonresettable two-position snap-acting blade electrically connected to ground. During normal operation current flows from the line source through the actuating portion of the thermostat metal assembly to the equipment. However, if an overcurrent condition occurs the heat generated in the actuating portion of the assembly will bend the assembly and cause it to make contact with the blade shorting the current from the line source to ground. As long as the overcurrent is not above a prescribed level, the assembly will bend back out of contact with the electrically grounded blade and again provide current to the equipment upon resumption of normal current levels. But if the overcurrent is above a preselected level, thermostat assembly will cause the nonresettable blade to snap to permanently electrically ground the device.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.