Transmitting loop arrangement for railroad cab signal and speed control system
First Claim
1. A loop arrangement for transmitting cab signal controls to a vehicle, provided with cab signal apparatus, traversing a stretch of fixed roadway divided into a plurality of sections, comprising in each section the combination of,(a) a first transmitting loop extending parallel to and within the section roadway generally along a first predetermined alignment but with an offset portion of preselected length at the section exit end positioned on a second predetermined alignment,(b) a second loop of the same preselected length as said offset portion of said first loop positioned at the exit end parallel to and within the section roadway along said first predetermined alignment,(c) a cab signal transmitter means at the exit end coupled to said first loop and responsive to advance traffic conditions along said stretch for transmitting into said first loop a selected one of a plurality of cab signal commands in accordance with the location of the next preceding vehicle,(d) said cab signal transmitter means also coupled to said second loop for transmitting the same commands but responsive to the occupancy condition of the adjoining advance section for interrupting the transmission of cab signal commands when said adjoining advance section is occupied by a vehicle,(e) a first cab signal pick-up means on each vehicle traversing the stretch positioned to respond to a loop signal in each loop positioned along said first predetermined alignment and coupled for actuating the associated cab signal apparatus to a movement control condition when a signal is present and to a cut-off condition when a signal is absent in such loop, and(f) a second cab signal pick-up means on each vehicle positioned to respond to a signal in said offset portion of said first loop and coupled for resetting said associated cab signal apparatus from said cut-off condition to an active condition only when a proceed cab signal command is received from that loop.
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Accused Products
Abstract
A wire loop for carrying cab signal or speed control commands is laid parallel to the rails along the track center line except at the exit end of each section where an offset portion of this loop is laid immediately adjacent one rail to form a cut-in signal source. A second loop is laid along the center line of the rails through this offset distance, which is equal to the stopping distance of the train from the restricted speed rate, and each loop is supplied by the same cab signal transmitter. Each train carries receiver coils positioned above the center line loops and above the cut-in loop positions. The normal cab signal or speed control apparatus is controlled by the signal picked up by the receiver coil above the centerline loops in the track. A separate cut-in receiver is controlled by signals picked up from the offset portion of the main loop but responds only to a proceed signal command. Interruption of signal transmission to the second loop when the advance track section is occupied halts a train moving in the approach section and cuts off the cab signal apparatus by interrupting a stick circuit of a cab signal control relay. When the cut-in receiver again responds to a proceed signal command, transmitted after the advance track section is again unoccupied, it energizes a cut-in relay which picks up the cab signal relay to again complete its stick circuit and activate the normal cab signal apparatus.
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Citations
15 Claims
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1. A loop arrangement for transmitting cab signal controls to a vehicle, provided with cab signal apparatus, traversing a stretch of fixed roadway divided into a plurality of sections, comprising in each section the combination of,
(a) a first transmitting loop extending parallel to and within the section roadway generally along a first predetermined alignment but with an offset portion of preselected length at the section exit end positioned on a second predetermined alignment, (b) a second loop of the same preselected length as said offset portion of said first loop positioned at the exit end parallel to and within the section roadway along said first predetermined alignment, (c) a cab signal transmitter means at the exit end coupled to said first loop and responsive to advance traffic conditions along said stretch for transmitting into said first loop a selected one of a plurality of cab signal commands in accordance with the location of the next preceding vehicle, (d) said cab signal transmitter means also coupled to said second loop for transmitting the same commands but responsive to the occupancy condition of the adjoining advance section for interrupting the transmission of cab signal commands when said adjoining advance section is occupied by a vehicle, (e) a first cab signal pick-up means on each vehicle traversing the stretch positioned to respond to a loop signal in each loop positioned along said first predetermined alignment and coupled for actuating the associated cab signal apparatus to a movement control condition when a signal is present and to a cut-off condition when a signal is absent in such loop, and (f) a second cab signal pick-up means on each vehicle positioned to respond to a signal in said offset portion of said first loop and coupled for resetting said associated cab signal apparatus from said cut-off condition to an active condition only when a proceed cab signal command is received from that loop.
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7. A cab signal control arrangement for a stretch of railroad track divided into a plurality of sections, and traversed by trains having cab signal apparatus responsive to signals received from the wayside right-of-way, comprising in combination,
(a) a first transmitting loop extending the length of each section between the rails, generally positioned along a first predetermined alignment but with an offset portion of preselected length along a different alignment at the exit end, (b) a second transmitting loop in each section of said preselected length and positioned between the rails along said first predetermined alignment parallel to said offset portion of said first loop at the exit end, (c) a cab signal transmitter means for each section coupled to the corresponding first and second loops at the section exit end and responsive to advance traffic conditions for transmitting one of a plurality of cab signal commands into each loop selected in accordance with the existing traffic conditions, (d) a track occupancy detection means for each section coupled for registering occupancy of the section by a train, (e) each track occupancy detection means further coupled for actuating the adjoining approach section transmitter means to transmit only a restricted signal command and for interrupting the transmission of signal commands into the adjoining approach section second loop, when a train occupancy of the associated section is registered, and (f) a first and a second signal pick-up means on each train, (1) said first pick-up means inductively coupled for receiving signal commands transmitted in loops positioned along said first predetermined alignment, (2) said second pick-up means inductively coupled for receiving signal commands transmitted in the offset portion of each first loop, (g) each first pick-up means coupled to said cab signal apparatus on that train for actuating a selected control of the train movement through each section in accordance with the selected signal command transmitted by the corresponding transmitter means, (h) each cab signal apparatus responsive to the absence of a signal command in the second loop of a section to stop the train from a restricted speed level within the length of that second loop.
Specification