Railroad track circuit for determining the occupancy status of a portion of a railroad

Patent metadata

Field	Value
Publication number	US-2018257685-A1
Application number	US-201715452114-A
Country	US
Kind code	A1
Filing date	Mar 7, 2017
Priority date	Mar 7, 2017
Publication date	Sep 13, 2018
Grant date	—

Abstract

A railroad track circuit determines occupancy status of a portion of a railroad track, and includes: a track including first and second rails; a transmitter including first and second connection terminals to generate a voltage between connection terminals; and first and second receiver units, each including first and second measurement terminals, the first and second receiver units measuring voltage between first and second measurement terminals. The output connection terminals of the transmitter connect to the respective rails at a first connection location, using first and second cables. The first measurement terminal of the first receiver unit is connected to the first rail at a second connection location, using a third cable and the first measurement terminal of the second receiver unit is connected to the first rail at a third location, using a fourth cable, the second and third locations forming respectively first and second boundaries of the track circuit.

First claim

1 . A railroad track circuit adapted to determine the occupancy status of a portion of a railroad track, said track circuit including:
a railroad track comprising first and second rails; a transmitter unit comprising first and second connection terminals and being adapted to generate a voltage signal between the first and second connection terminals; a first and a second receiver units, each comprising a first measurement terminal and a second measurement terminal, the first and a second receiver units being each adapted to measure a voltage signal between their respective first and second measurement terminals;
and wherein:
the first and second output connection terminals of the transmitter unit are connected to the first and second rails at a first connection location, respectively using a first cable and a second cable;
the first measurement terminal of the first receiver unit is connected to the first rail at a second connection location, using a third cable and the first measurement terminal of the second receiver unit is connected to the first rail at a third location, using a fourth cable, the second and third locations forming respectively first and second boundaries of the track circuit;
the second measurement terminal of the first and second receiver units are both connected to the second terminal of the transmitter unit by means of wayside cables.

2 . The railroad track circuit of claim 1 , wherein the transmitter unit is adapted to generate high frequency voltage signals, with a frequency greater than or equal to 10 kHz.

3 . The railroad track circuit of claim 1 , wherein the first and the second locations are equidistant from the transmitter unit.

4 . The railroad track circuit of claim 1 , wherein it comprises an electronic calculator unit programmed to compare the voltage signals measured by the first and second measurement units with at least one predefined threshold value, the occupancy status being determined as a result of this comparison.

Assignees

• Alstom Transp Tech

Inventors

• Nagrodsky Nicholas
• Fries Jeffrey

Classifications

• B61L1/187 Primary

  Use of alternating current · CPC title

• B61L25/025 Primary

  Absolute localisation, e.g. providing geodetic coordinates · CPC title

• E01B26/00

  Tracks or track components not covered by any one of the preceding groups · CPC title