Patent · US Expired

Switch testing

US4692939A · kind A · utility

5Cited by
1References
9Claims
0Family size

Assignee

Inventor

Key dates

Filing dateMar 19, 1986
Grant dateSep 8, 1987
Priority date
Expiry dateMar 19, 2006

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04Q1/24
  • WIPO fieldTelecommunications
  • WIPO sectorElectrical engineering

Abstract

Switches of telephone grids are tested for delayed action subsequent to, but within a number of milliseconds after, actuating the opening or closing of the switches. Excessive delay indicates approaching failure.

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