US3794833A — Train speed control system

Claim 1

Independent Claim 395 words

A train control system for trains moving along a stretch of track, comprising in combination, a. a track circuit arrangement dividing said stretch into a plurality of sections and including a center fed detector track circuit for each pair of adjacent track sections supplied by a transmitter means with energy of a distinctive frequency different from that supplied other pairs of sections in said track stretch, 1. the track circuit for each pair of sections individually detecting the occupancy of each section by a train; b. said track circuit arrangement further including another energy source for each track section connected at the exit end thereof for supplying to the corresponding section at times energy with a single preselected frequency different from any of said distinctive frequencies and modulated with one of a plurality of allowable speed signals, selected in accordance with the detected occupancy conditions of sections in advance, 1. each other energy source being controlled by the associated track circuits for supplying said preselected frequency energy only when the corresponding section is occupied and at least the next advance section is unoccupied, c. receiver means on each train inductively coupled to the track rails for receiving the modulated preselected frequency energy supplied by a second energy source to the track section then occupied by that train and responsive thereto for producing a distinctive output in accordance with the selected modulation signal, d. registry means on each train connected for receiving the output of the associated receiver means and recording an indication of the allowable train speed, e. speed measuring means on each train coupled to the train propulsion apparatus for registering an indication of the actual train speed, f. overspeed detection means on each train jointly controlled by the associated registry means and the associated speed measuring means for comparing allowable and actual train speeds and further connected to the train braking apparatus for at times initiating an automatic brake application to reduce the train speed in response to a detected overspeed condition of actual speed greater than allowable speed, and g. time delay means on each train controlled by the associated overspeed detection means and responsive to deceleration of said train for measuring a predetermined time period after an overspeed condition detection and connected for inhibiting an automatic brake application when deceleration of said train is otherwise initiated during said predetermined time period.

Claim 2

Dependent Claim 395 words

A train control system for trains moving along a stretch of track, comprising in combination, a. a track circuit arrangement dividing said stretch into a plurality of sections and including a center fed detector track circuit for each pair of adjacent track sections supplied by a transmitter means with energy of a distinctive frequency different from that supplied other pairs of sections in said track stretch, 1. the track circuit for each pair of sections individually detecting the occupancy of each section by a train; b. said track circuit arrangement further including another energy source for each track section connected at the exit end thereof for supplying to the corresponding section at times energy with a single preselected frequency different from any of said distinctive frequencies and modulated with one of a plurality of allowable speed signals, selected in accordance with the detected occupancy conditions of sections in advance, 1. each other energy source being controlled by the associated track circuits for supplying said preselected frequency energy only when the corresponding section is occupied and at least the next advance section is unoccupied, c. receiver means on each train inductively coupled to the track rails for receiving the modulated preselected frequency energy supplied by a second energy source to the track section then occupied by that train and responsive thereto for producing a distinctive output in accordance with the selected modulation signal, d. registry means on each train connected for receiving the output of the associated receiver means and recording an indication of the allowable train speed, e. speed measuring means on each train coupled to the train propulsion apparatus for registering an indication of the actual train speed, f. overspeed detection means on each train jointly controlled by the associated registry means and the associated speed measuring means for comparing allowable and actual train speeds and further connected to the train braking apparatus for at times initiating an automatic brake application to reduce the train speed in response to a detected overspeed condition of actual speed greater than allowable speed, and g. time delay means on each train controlled by the associated overspeed detection means and responsive to deceleration of said train for measuring a predetermined time period after an overspeed condition detection and connected for inhibiting an automatic brake application when deceleration of said train is otherwise initiated during said predetermined time period.

Claim 3

Dependent Claim 42 words

A train speed control system for trains moving along a stretch of track, comprising in combination, a. a track circuit arrangement dividing said track stretch into preselected track sections and operable for detecting the presence and location of trains within said stretch,

Claim 4

Dependent Claim 42 words

A train speed control system for trains moving along a stretch of track, comprising in combination, a. a track circuit arrangement dividing said track stretch into preselected track sections and operable for detecting the presence and location of trains within said stretch,

Claim 5

Dependent Claim 67 words

the occupancy detection means for that particular section to complete the energy supply when an approaching train occupies that section, and f. train control aPparatus on each train traversing said stretch responsive to the modulated selected frequency energy successively supplied to the sections and connected for monitoring the speed of that train and maintaining the speed below the maximum allowable speed designated by the received code frequency.

Claim 6

Dependent Claim 67 words

the occupancy detection means for that particular section to complete the energy supply when an approaching train occupies that section, and f. train control aPparatus on each train traversing said stretch responsive to the modulated selected frequency energy successively supplied to the sections and connected for monitoring the speed of that train and maintaining the speed below the maximum allowable speed designated by the received code frequency.

Claim 7

Dependent Claim 168 words

A speed control system as defined in claim 2 in which, a. said automatic brake application control means has only a nonbraking, a normal braking, and an emergency braking condition and is connected for actuating a train service brake application when operated to its normal braking condition and an emergency brake application when operated to its emergency braking condition, b. said brake application control means operates to its normal braking condition a first preselected time interval and to its emergency braking condition a second and longer preselected time interval after the overspeed detection means detects that the actual speed is greater than the allowable speed if no other braking action has occurred, and c. said brake assurance means is connected in its second position for retaining said brake application control means in its nonbraking condition if train deceleration occurs prior to the expiration of said first time interval and at least in its normal braking condition if deceleration occurs prior to the expiration of said second time interval.

Claim 8

Dependent Claim 182 words

A speed control system for railroad trains moving along a stretch of track, comprising in combination, a. a track circuit arrangement connected for dividing said track stretch into a plurality of sections and for normally supplying energy having a distinctive frequency, to each adjoining pair of track sections at their common junction location, to feed through the rails to the distant end of each section, b. an occupancy detection means coupled at the distant end of each of the pair of track sections supplied with the same distinctive frequency energy for registering the occupancy condition of the corresponding section, c. a second source of energy for each track section coupled at the exit end thereof for at times supplying energy having a selected frequency different from said plurality of distinct frequencies and the same for each section, d. a modulating means coupled to each second source and controlled by said track circuit arrangement for modulating the second source energy by a selected one of a plurality of code frequencies in accordance with the section occupancy conditions in advance of the corresponding section,

Claim 9

Dependent Claim 182 words

A speed control system for railroad trains moving along a stretch of track, comprising in combination, a. a track circuit arrangement connected for dividing said track stretch into a plurality of sections and for normally supplying energy having a distinctive frequency, to each adjoining pair of track sections at their common junction location, to feed through the rails to the distant end of each section, b. an occupancy detection means coupled at the distant end of each of the pair of track sections supplied with the same distinctive frequency energy for registering the occupancy condition of the corresponding section, c. a second source of energy for each track section coupled at the exit end thereof for at times supplying energy having a selected frequency different from said plurality of distinct frequencies and the same for each section, d. a modulating means coupled to each second source and controlled by said track circuit arrangement for modulating the second source energy by a selected one of a plurality of code frequencies in accordance with the section occupancy conditions in advance of the corresponding section,

Claim 10

Dependent Claim 106 words

A speed control system as defined in claim 2 in which each train-carried apparatus further includes, a. a zero speed detection means coupled to said speed measuring for registering a zero train speed condition, b. said zero speed detection means producing another output when zero train speed is detected and coupled for holding said overspeed detection means in its nonactuating condition to permit that train to restart when an allowed speed is registered, c. said zero speed detection means also connected for holding said brake application control means in its nonbraking condition when a registered zero speed condition results from other than an automatic brake application.

Claim 11

Dependent Claim 188 words

A speed control system as defined in claim 5 further including in each train-carried apparatus, a. a stop and proceed restricted speed relay means normally occupying a first position and operable at times to a second position, b. a timing means controlled by said zero speed detection means for measuring a predetermined delay period after zero speed is registered, c. a first circuit means completed by said restricted speed relay means in its second position for controlling said overspeed detection means to authorize train movement at a preselected restricted speed when no code frequency is received, d. an energizing circuit means connected for operating said restricted speed relay to its second position and completed jointly by said signal receiving means when no code frequency is being received, said brake application control means in its nonbraking condition, and said zero speed detection means when a zero speed condition is registered, and e. a second circuit means completed by said timing means when said delay period is expired for alternately controlling said overspeed detection means to authorize train movement at said preselected restricted speed when no code frequency is received.

Claim 12

Dependent Claim 109 words

A speed control system as defined in claim 4 which further includes, a. traffic direction means operable to a first and second positions for establishing normal or reverse direction traffic, respectively, through the track stretch, b. remotely controlled switch means connected for operating said traffic direction means to its first or second positions as normal or reverse traffic selection commands are registered by said switch means, and c. the supply of second source energy at each junction between sections is further controlled by said traffic direction means for supplying such energy only to that section whose exit end is at that junction in accordance with the established traffic direction.

Claim 13

Dependent Claim 45 words

A speed control system as defined in claim 7 in which the track section limits are defined by cross-bond devices connected between the rails without insulated joints, said energy sources and detection means being coupled to the section rails by transformer windings of said crossbonds.

Claim 14

Dependent Claim 33 words

A speed control system as defined in claim 8 in which all apparatus except said crossbond devices for said track circuit arrangement for said stretch of track is located at a central housing.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1977-02-25	1977-08-27	1978-02-26	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1981-02-25	1981-08-27	1982-02-26	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1985-02-25	1985-08-27	1986-02-26	$7700.00	Window Closed / Lapsed

Train speed control system

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