Master-Satellite railway track circuit
AssigneeUnion Switch & Signal Inc.
InventorRaymond C. Franke
Life of this patent
Estimating the term…
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.
Claims40
A railway track circuit for connecting to a track section to detect the presence of a railway vehicle on such track section comprising:
- (a) a master transmitter having means for transmitting a master signal onto one end of such track section;
- (b) a satellite receiver having means for receiving said mater signal at the opposite end of such track section;
- (c) a satellite transmitter having means for transmitting a satellite signal onto said opposite end of such track section only in response to the receipt of said master signal by said satellite receiver;
- (d) a master receiver having means for receiving said satellite signal at said one end of such track section;
- (e) said transmitters and said receivers each have an impedance less than 0.3 ohms as coupled to the rails of such track section;
- and
- (f) said satellite transmitter transmits a satellite linkup signal in response to said satellite receiver detecting a master link-up signal.
A railway track circuit for connecting to a track section to detect the presence of a railway vehicle on such track section comprising:
- (a) a master transmitter having means for transmitting a master signal onto one end of such track section;
- (b) a satellite receiver having means for receiving said master signal at the opposite end of such track section;
- (c) a satellite transmitter having means for transmitting a satellite signal onto said opposite end of such track section only in response to the receipt of said master signal by said satellite receiver;
- (d) a master receiver having means for receiving said satellite signal at said one end of such track section;
- and
- (e) said master transmitter and said satellite transmitter each have a low impedance and have an impedance greater than the individual impedance of said master receiver and said satellite receiver as coupled to the rails of such track section.
A railway track circuit for connecting to a track section to detect the presence of a railway vehicle on such track section comprising:
- (a) a master transmitter having means for transmitting a master signal onto one end of such track section;
- (b) a satellite receiver having means for receiving said master signal at the opposite end of such track section;
- (c) a satellite transmitter having means for transmitting a satellite signal onto said opposite end of such track section only in response to the receipt of said master signal by said satellite receiver;
- (d) a master receiver having means for receiving said satellite signal at said one end of such track section;
- and
- (e) said master receiver and said satellite receiver each have a low impedance and each have an impedance greater than the individual impedance of said master transmitter and said satellite transmitter as coupled to the rails of such track.
A method of detecting the presence of railway vehicles and broken rail between a master and a satellite location comprising:
- (a) monitoring the rails at such master location for a period of time with an impedance of less than 0.3 ohms as coupled to said rails;
- (b) sequentially transmitting a master link-up signal at the master location with an impedance greater than 0.3 ohms as coupled to said rails in response to no signal detected during said monitoring, and sequentially transmitting at said master location with an impedance greater than 0.3 ohms as coupled to said rails a master signal other than said master link up signal in response to said satellite signal;
- (c) monitoring the rails at such satellite location with an impedance of less than 0.3 ohms as coupled to said rails, and transmitting at said satellite location with an impedance greater than 0.3 ohms as coupled to said rails a satellite link-up signal in response to receipt of a master link-up signal, and transmitting at said satellite location with an impedance greater than 0.3 ohms as coupled to said rails a satellite signal other than said satellite link-up signal in response to receipt of said master signals other than said master link-up signals;
- (d) indicating an unoccupied condition at said satellite location only in response to receipt of master signals other than said master link-up signal;
- and
- (e) indicating an unoccupied condition at said master location in response to receipt of satellite signals other than said satellite link-up signal.
A method of detecting the presence of railway vehicles and broken rail between a master and a satellite location comprising:
- (a) monitoring the rails at such master location for a period of time with an impedance greater than 0.3 ohms as coupled to said rails;
- (b) sequentially transmitting a master link-up signal at the master location with an impedance less than 0.3 ohms as coupled to said rails in response to no signal detected during said monitoring, and sequentially transmitting at said master location with an impedance less than 0.3 ohms as coupled to said rails a master signal other than said master link-up signal in response to said satellite signal;
- (c) monitoring the rails at such satellite location with an impedance greater than 0.3 ohms as coupled to said rails, and transmitting with an impedance of less than 0.3 ohms as coupled to said rails, a satellite link-up signal in response to receipt of a master link-up signal, and transmitting with an impedance less than 0.3 ohms as coupled to said rails a satellite signal other than said satellite linkup signal in response to receipt of said master signals other than said master link-up signals;
- (d) indicating an unoccupied condition at said satellite location only in response to receipt of master signals other than said master link-up signal;
- an
- (e) indicating an unoccupied condition at said master location in response to receipt of satellite signals other than said satellite link-up signal.
Dependencies are inferred from the claim text.