The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.

The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.

Date of Patent:
Sep. 08, 1992

Filed:

Mar. 27, 1991
Applicant:
Inventor:

Raymond C Franke, Glenshaw, PA (US);

Assignee:

Union Switch & Signal Inc., Pittsburgh, PA (US);

Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
B61L / ;
U.S. Cl.
CPC ...
2461 / ; 246 / ;
Abstract

A railway track circuit for protection of an extended track block having a master unit at one end of the block and a satellite unit at the other. Each master and satellite unit having transmitting and receiving capabilities. The output impedance of the transmitters or of the receivers is of a low impedance as connected to the rails. Through an alternative transmit and receive sequence a link-up between the master and satellite units provides detection of broken rail and/or shunts from each end of the track circuit. The use of low impedance and detection at both ends of the section permit extended length track circuits.


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