Patent · US Active

Safety circuit

US9158289B2 · kind B2 · utility

0Cited by

7References

21Claims

0Family size

Assignee

OTIS ELEVATOR COMPANY · US

Inventors

Peter Herkel · Berlin, DE
Juergen Gewinner · Berlin, DE
Dirk H. Tegtmeier · Berlin, DE

Key dates

Filing date	Apr 23, 2010
Grant date	Oct 13, 2015
Priority date	—
Expiry date	Nov 30, 2031

Classification

Technology area (CPC B)Performing Operations; Transporting
CPC primaryB66B13/22
WIPO fieldControl
WIPO sectorInstruments

Abstract

An exemplary safety circuit includes a plurality of contacts that are configured to establish a conductive path across the contacts when the contacts are in electrically conductive contact with each other. The contacts selectively interrupt the conductive path across them when the contacts are separated. A controller selectively introduces a voltage pulse across the contacts at a voltage level that is effective to overcome an electrical resistance of any contamination on at least one of the contacts. The controller introduces the voltage pulse at least when the contacts are expected to be in contact to establish the conductive path.

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