Patent · US Expired

Two-threshold changeover pressure switch

US4778963A · kind A · utility

3Cited by
11References
9Claims
0Family size

Assignee

Inventors

Key dates

Filing dateApr 13, 1987
Grant dateOct 18, 1988
Priority date
Expiry dateApr 13, 2007

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH01H35/34
  • WIPO fieldElectrical machinery, apparatus, energy
  • WIPO sectorElectrical engineering

Abstract

The invention relates to a pressure switch comprising an insulating housing fitted with contact tabs and receiving moving contact members, a conductive washer, and a membrane subjected to pressure. The pressure switch includes two moving insulating members (15, 19), two contact members (16, 20), two associated springs (17, 21), and a pusher (14) which is conductive and in contact with the membrane. The fixed conductive washer (11) has a central hole through which a cylindrical projection provided on one of the insulating moving members (15) passes, with a rod on the pusher (14) sliding inside said cylindrical projection so that the insulating moving members (15, 19), the contact members (16, 20), and the associated springs (17, 21) are all disposed on the same side of the fixed conductive washer which therefore constitutes one end of the cavity (9) in the insulating housing. The invention is applicable to monitoring and providing warnings concerning pressure variations going beyond one or other of two predetermined thresholds, and in particular to monitoring hydraulic circuits in vehicles provided for lubrication or for braking purposes. These thresholds may respectively indicate t…

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