Patent · US Expired

Thermal switch device and method of making

US4017818A · kind A · utility

1Cited by
5References
16Claims
0Family size

Assignee

Inventor

Key dates

Filing dateDec 22, 1975
Grant dateApr 12, 1977
Priority date
Expiry dateDec 22, 1995

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH01H37/764
  • WIPO fieldElectrical machinery, apparatus, energy
  • WIPO sectorElectrical engineering

Abstract

A thermal switch for automatically opening a circuit when the ambient temperature is increased to a predetermined level. A pair of conductor wires are arranged in side by side fashion with extremities extending in the same direction. A spring portion is included in at least one of the conductor wires to provide stored energy when the spring is biased into electrical contact with each other. A localized contact region is included in the conductor wire in the region below the spring portion. The extremities, contact region, and spring being encapsulated with a heat fusible material which biases the conductor wires into contact with each other and which is coated with a rigid insulating material to retain the conductor wires electrically insulated from each other except at the contact region. The heat fusible material holding the conductors into electrical contact until the temperature level reaches the level at which the fusible material flows thereby allowing the contacts to be separated due to the energy stored by the spring.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.