Patent · US Expired

Electrical heating element

US4021769A · kind A · utility

6Cited by
1References
2Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMar 18, 1976
Grant dateMay 3, 1977
Priority date
Expiry dateMar 18, 1996

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH01C3/14
  • WIPO fieldElectrical machinery, apparatus, energy
  • WIPO sectorElectrical engineering

Abstract

An elongated electrical heating element comprises intertwisted helical strands of metal wire. Some of the strands extend the full length of the heating element and other strands extend predetermined shorter distances to provide two or more zones having differing electric resistances and therefore differing operating temperatures.

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