Abstract: A system for transmitting data between the ground and moving vehicles, for example consisting of a stretch of railway line V.sub.1 having beacons between the rails. The various beacons are connected to nodes, e.g. N.sub.i, N.sub.j, N.sub.k, which are in turn linked to a nodal transmission point (CNT) and to fixed railway installations controlling, for example, a points motor. The system is useful particularly in the field of data transmission between the ground and moving railway vehicles such as locomotives, passenger coaches, freight wagons, and train units.

Abstract: An improved audio frequency track circuit system utilizes a synchronous train detection arrangement and reduces the number of fixed code rate modulated carrier signals. As few as two carrier signals are alternately applied at discrete points along a pair of jointless track rails to define the transmitter ends of the track sections, with complementary receivers defining the opposite ends. The two carrier signals are coded at one of two phase angles which are 90.degree. out-of-phase so that, when assigned, the nearest possible interfering signal is 90.degree. out-of-phase and is rejected thereby. Like carrier frequency transmitter/receiver arrangements are disposed on opposite sides of an insulated joint but are coded 180.degree. out-of-phase so that a breakdown of the insulated joint is detected and the false code signal is rejected.

Abstract: A system for transmitting data long rails of a railway track for reception by a receiver mounted on a vehicle of the train. The system includes resonance circuits defining contiguous zones which are independent of a block system of the railway track. An insulative conductive loop is placed between the rails of the track and proximate the resonance circuits. An AC generator and modulation are provided to produce a modulated carrier frequency corresponding to the data to be transmitted and is coupled to the conductive loop. The receiver is positioned at the front of the train when the conductive loop is positioned near the downstream side of each zone and toward the rear of the train when the conductive loop is positioned toward the upstream side of each zone relative to the direction of train travel.

Abstract: An arrangement enabling continuous control of vehicles on a track divided into individual areas comprises at least one track-conductor loop associated with the track in each of the areas having N transpositions therein, where N is an integer greater than two, the loop communicating data between the vehicles and a fixed control station by being coupled at opposite ends thereof to a different one of two supply units coupled to the control station and by being inductively coupled to communicating equipment on the vehicles. The one loop further comprises coupling elements disposed intermediate adjacent ones of the N transpositions to subdivide the loop into N track-conductor loops.

Abstract: An audio frequency track circuit with improved security in the train detection function for rapid transit applications for use with uninsulated rails includes an improved transmitter and receiver. The transmitter modulates a track frequency carrier with a fixed code rate, regardless of the code rate employed to modulate the train information frequency. The receiver includes a decoder tuned to the track frequency modulation rate. By using such a sharply tuned decoder, the noise protection threshold is increased. Because of its application to uninsulated rails, with the associated lack of hard track circuit boundaries, adjacent track circuits have different track frequency modulation rates to insure that the modulated track frequency signal, from one track circuit, is not effective to operate a track relay in another circuit even under failure conditions.

Abstract: A fail-safe electronic time delay circuit for providing a predetermined time delay period having an emitter-follower amplifier connectable to a source of recurrent signals, a voltage doubling rectifier for rectifying the amplified recurrent signals and for charging a capacitor which powers a tickler coil transistor oscillator, a pair of complementary switching transistors which are alternately rendered conductive by the a.c. oscillations of the transistor oscillator, a rectifier having a capacitor which is charged when one of the pair of complementary switching transistors is conductive and which is discharged through a vital relay when the other of the pair of complementary switching transistors is rendered conductive.

Abstract: The present invention relates to a train vehicle speed control apparatus which recognizes a change in one of the acceleration rate or the deceleration rate of a train moving along the track and the control of the train velocity in relation to what distance will be required for a desired operation of the train such as a predetermined decrease in the train speed or a stopping of the train. If the deceleration rate has changed, for example, the fixed physical system limits what control can be exercised and the velocity of the train can be modified to adjust the actual stopping distance used by the train or with a fixed stopping distance desired then the permitted train velocity can be changed.

Abstract: A safety device for a transport system in which a vehicle travels on a track divided into sequential sections operates to stop the vehicle when a parameter representing the motion of the vehicle exceeds a threshold in the course of travelling over a track section. The device comprises two comparators each delivering during passage of the vehicle in each track section a comparison signal having a first value when the parameter remains within the threshold and a second value when the parameter exceeds the threshold. A coincidence detector is connected to receive the output signals of the two comparators and operates to initiate emergency braking of the vehicle if the output signals of the two comparators do not simultaneously have the same value during travel in a track section.

Abstract: A method and apparatus for continuous supervision of both a vehicle's speed and deceleration over a track, provides overspeed detection in one set of conditions and under-deceleration detection under other conditions. The apparatus does not provide automatic driving, but is used in conjunction with either automatic driving equipment or manual driving of the vehicle. The process involved comprises the steps of transmitting to the vehicle an exit speed, defined as a speed limit to be observed on leaving a particular block section of the track upon which the vehicle travels. The exit speed is stored in the vehicle, and comparisons are made with a stored exit speed for the preceding block section. The process further includes a continuous measurement of both actual speed and deceleration of the vehicle, and provides for initiation of emergency braking dependent upon the results of the comparison and measurement steps.

Abstract: A method and apparatus is provided for communicating information in the form of plural items of data between a first station and a rail vehicle by transmission of pulses at predetermined repetition rates along railway tracks including a transmitting station for generating the information pulses having control apparatus receiving a particular data item as an input for selecting a repetition rate to represent the data item for transmission and generating apparatus connected to the control apparatus for generating the information pulses. The information pulses are coupled to railway tracks which transmit the generated information. A receiving station receives the information pulses from the tracks and includes sensing apparatus for sensing the information pulses and apparatus for removing interference signals received along with the information pulses, the interference signals being attributable to a number of causes which include unbalanced traction return currents and/or transmission interference.

Abstract: Alternating current track circuits are provided for the several adjoining track sections of a stretch of railway track, each of the track circuits comprising an alternating current code transmitter and an alternating current code receiver connected to track rails at opposite ends of the associated section. Circuit apparatus including an alternating current line circuit extending along the stretch of railway track is provided for normally communicating alternating current from the line circuit through rails of the associated track sections, the alternating current being modulated at a selected rate code and current in any two adjoining track sections being of opposite instantaneous polarity for broken down joint protection. Phase sensing apparatus is provided at a receiving end of each track section including a comparator for comparing the rate code modulated alternating current communicated through the track rails with a steady reference source connected to the line circuit.

Abstract: A stretch of railway track, has a high frequency track circuit transmitter and receiver and a cab signal transmitter coupled across track rails at each of several locations marking the ends of track sections along a stretch of railway track. Each location has an impedance bond having a primary winding connected across the track rails and having toroid secondary windings tuned to assigned distinctive high frequencies for coupling a track transmitter and a track receiver to the track rails. A loop circuit is also provided at each location, including a tuned loop, for inductively coupling a cab signal code transmitter to the track rails independent of the impedance bond. The tuned toroid coils and the loop circuit are connected in series to one end of a two wire line circuit, which, at its other end, is connected to a track circuit high frequency transmitteer, a track circuit receiver, and a cab signal transmitter connected in multiple.

Abstract: The present invention relates to a train vehicle speed control signal providing apparatus operative with a frequency command speed control signal, and relates to the generation of the desired speed code signals in such a frequency rate system. Two separate and independent physical and electrical operations provide each of the respective desired frequency speed code signals in combination with a comparison step to provide an output speed code signal only if the two input frequency signals are each at the desired frequency.

Abstract: A communication system for track or guideway operated vehicles is disclosed. The system is adapted for two-way transmission between a vehicle and a wayside station and is provided with a transmission line of special configuration along the wayside. The transmission line comprises three conductors each having a wave configuration with the waves disposed in three-phase relationship and a return conductor which is also of wave configuration. The vehicle transmitter section is provided with an inductive loop which is coupled with the transmission line and is energized with a continuous wave signal. This produces signals on the three phase conductors which have an envelope frequency proportional to vehicle speed and a phase relationship corresponding to the relative position of the wave configurations of the phase conductors. Thus, vehicle speed may be derived by measuring frequency and vehicle position may be derived by counting cycles or pulses from a given starting point.

Abstract: A collision avoidance system adapted for railroad use comprising a track having connected thereto a plurality of first signal transmitters exciting the track by a first control signal within a first frequency bandpass range and a plurality of second signal transmitters interspaced between the first signal transmitters in an alternating arrangement, such second transmitters exciting the track by a second control signal within a second frequency bandpass range. While the first and second control signals are respectively within the first and second bandpass range, individual ones thereof are separated by frequency increments from the other control signals within the corresponding bandpass range such that any beats therebetween are of a relatively high frequency.