Combined thermostatic control and thermal fuse overtemperature protector for electrical heating appliances
US4313047A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 6, 1980 |
| Grant date | Jan 26, 1982 |
| Priority date | — |
| Expiry date | Mar 6, 2000 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01H37/002
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An overtemperature protector for an appliance having an electrical heating element, the overtemperature protector being formed basically of just a spring blade positionable to bring a contact on the surface of the blade into circuit-energizing engagement with a fixed contact, and an insulator-capped fusible pin retaining the blade in that position. Excessive heat in the appliance softens the pin, allowing the spring blade force on the insulator cap to shear the pin and interrupt the circuit. The overtemperature protector is preferably incorporated in a thermostatic control, the fixed contact being supported on a lateral extension projecting from one circuit element of the thermostat assembly and the spring blade being supported within the assembly with an insulating spacer separating it from the thermostat element having the lateral extension. The spring blade is preferably sickle-shaped for compactness despite having a long length for low force to minimize effects of creep of the fusible pin. The spring blade engages the fusible pin at a point well beyond the contact, the result being that a much smaller force is exerted on the pin for any desired force between the contacts.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.