Abstract: An apparatus and method are provided for interfacing railway controllers with light units, such as LED light unit arrays, to shunt and/or disable test signals not traditionally intended to test non-incandescent light unit arrays.

Abstract: Detection of a zero speed or moving railway vehicle wheel or other metallic object is accomplished by providing a balanced E-core inductive detector. An exciter coil on the center leg of the E-core inductively couples a pair of sensor coils connected in series opposition on the outside legs of the E-core. A voltage detector responsive to unbalancing of the E-core magnetic field by a train wheel or other metallic object is connected to the output of the sensor coils. A zero speed wheel located at the center of the magnetic field is detected by using the output of one of the sensor coils compared with the phase shifted and amplitude adjusted exciter signal. Speed and direction of travel are also determined by monitoring wheel detection output sequencing and timing.

Abstract: A reliable and consistent electrical contact path between the rails of a section of railroad track established by the shunting effect of the wheels and axles of a train is ensured by applying time-spaced, short duration electrical pulses to the rails at a voltage level sufficient to overcome poor wheel/rail contact. Each of the pulses is produced by a generator that discharges a capacitor across the rails. The narrow pulse width inductively isolates the pulse generator and associated track section from adjacent stretches of track, and the spacing between pulses further avoids interference with other types of electrical track equipment. A detector responsive to the voltage on the rails disables the pulse generator when the received voltage exceeds a threshold and thus indicates that no train wheels are present in the track section. In a grade crossing warning system, once activated the pulse generator and detector assume the role of the island detection circuit and maintain the crossing warning.

Abstract: A track circuit with diagnostic capability differentiates between an occupied track circuit and one in which a conductor of the track circuit (one of the rails) is broken. Transceiver units are provided at the respective ends of the track circuit and operate alternately in transmit and receive modes. The applied voltage and current are measured at the transmitting unit, and the received voltage and current are sensed and measured at the receiving unit. From these measurements made successively as the units alternately transmit and receive, each unit can determine whether the track is available or unavailable and, if unavailable, whether the track has a broken rail. A microprocessor in each unit distinguishes a broken rail from an occupied track when an increase in the applied transmitting voltage at the unit occurs simultaneously with a decrease in each of the other voltage and current measurements.

Abstract: A vital wheel detector for railways injects an oscillating electrical current into a short rail segment and produces a monitor signal in response the magnetic field around the rail. A high Q pickup coil is employed which, when a car wheel is present on the rail segment, sharply decreases in Q and significantly reduces the level of the monitor signal. Any failure of the detector apparatus is in a safe mode, as a loss of rail current results in a loss of the monitor signal whether through an electrical or a mechanical failure. Also, internal mechanical or electrical failures either interrupt the current to the rail or interrupt transmission of the monitor signal to the processing logic.

Abstract: Inductive pickups for sensing coded cab current information employ short ferrite cores and exhibit a pronounced roll-off characteristic to provide a detection system that may be used with locomotives powered by alternating current traction motors. Desired response is enhanced by connecting the inductors in phase in a tuned circuit and by employing a cancelling coil in phase opposition that receives interfering motor noise but is insensitive to the coded information.

Abstract: Apparatus for sensing coded cab current information in a high level noise environment, caused by the magnetic fields of AC traction motors employed in the locomotive, utilizes pickup coils each having an upright axis and an axially extending, ferrite core. The coils are employed in pairs on a common magnetic structure located over an underlying rail, the coils being spaced apart horizontally and transversely of the rail. Magnetic flux resulting from the cab current is directed in opposite axial directions through the coils, whereas magnetic flux produced by the AC traction motors is directed through the coils in the same axial directions. This results in the addition of the voltages induced in the coils by the cab current, and voltage subtraction in response to the interfering magnetic field produced by the AC motors.

Abstract: A train control system employs a series of wayside control units spaced along the track, each of which has responsibility for the control of trains in a corresponding local area and monitors track availability and signal status in its local area. Each wayside unit has a data base in memory that comprises fixed data defining an operational profile of the associated local area, and is provided with a data radio for transmitting profile messages containing the fixed data for that area and authority messages containing the dynamic data bearing track availability and signal status information. A data radio in a receive mode on a train receives the data transmissions from the wayside unit or units responsible for its control, and an on-board computer determines the proper train control instructions from the received data.

Abstract: Apparatus for mounting an impedance bond or other device between a pair of spaced, concrete railroad ties employs a clamping plate which overlies and spans the ties, and a pair of clamping feet that are installed between the ties. Components interconnecting the plate and the feet draw the plate and feet toward one another to securely clamp the ties therebetween. The device to be mounted between the ties is secured to the undersurface of the plate and is thus held in a fixed position in the space between the ties. The spacing between the feet may be varied to accommodate different tie spacings, and the entire installation is accomplished without embedding fasteners in the concrete tie material.

Abstract: A train control-system employs beacon transponders along the track to transmit fixed data to a passing train in addition to dynamic data relating to track availability and routing provided by encoded cab signals transmitted in the track. The fixed data includes the location of block boundaries and distances to such boundaries, timetable speed limits, and the distance to a point along the track at which a speed restriction is in effect. This data and other fixed information is integrated with the dynamic data in an on-board computer which determines train control instructions from the received data and displays the instructions to the train crew. The system is capable of enforcing any restrictive instructions that are not obeyed.

Abstract: A three-terminal surge arrestor unit employs air gaps augmented with semiconductors to protect a circuit having two ungrounded conductors. Conductive electrodes and the semiconductors are mounted on a common axis in a sandwich arrangement and secured in fixed relative positions. Two air gap lightning arrestors provide current paths for the respective conductors to ground in response to lightning strikes or other damaging surges, and an equalizer is incorporated in the electrode configuration to establish a current path between the conductors to protect them from an excessive voltage differential. The resulting configuration is a single, three-terminal unit designed to replace multiple unit air gap systems and gas tube arrestors.

Abstract: A train control system employs beacon transponders along the track to transmit fixed data to a passing train in addition to dynamic data relating to track availability and routing provided by encoded cab signals transmitted in the track. The fixed data includes the location of block boundaries and distances to such boundaries, timetable speed limits, and the distance to a point along the track at which a speed restriction is in effect. This data and other fixed information is integrated with the dynamic data in an on-board computer which determines train control instructions from the received data and displays the instructions to the train crew. The system is capable of enforcing any restrictive instructions that are not obeyed.

Abstract: A reliable and consistent electrical contact path between the rails of a railroad track established by the shunting effect of the wheels and axles of a train is ensured by applying an alternating current signal to the rails at a voltage level sufficient to overcome poor wheel/rail contact and cause a wetting current to flow between the rails. This likewise provides a current path for railroad control and communication signals, such as the island circuit signal of a grade crossing warning system. The effective range of the wetting current signal is limited by providing the signal with a frequency of 10 KHz or higher to inductively isolate the signal source and associated stretch of track from any shunts beyond that stretch. To avoid interference with other types of electronic track equipment, the signal is applied only when required. In grade crossing warning systems, it is controlled in a fail-safe manner.

Abstract: Overheated railroad journal bearings, wheels, and other wheel components on a moving or stationary railroad train are detected by amplifying the current signal from an infrared radiation sensor comprising a pytoelectric cell. A reference temperature is sensed by chopping the incident infrared radiation with an asynchronous shutter that momentarilly closes at successive time spacings of shorter duration than the scanning period of the sensor. The amplified signal is converted to a digital signal and processed by a microcontroller and associated hardware and software. The detector automatically and periodically calibrates itself and compensates the temperature signals for any temperature difference between the ambient external temperature and the temperature inside the detector housing. The output signal may be digital or analog.

Abstract: Overheated railroad journal bearings, wheels, and other wheel components on a moving or stationary railroad train are detected by amplifying the current signal from an infrared radiation sensor comprising a pyroelectric cell. A reference temperature is sensed by chopping the incident infrared radiation with an asynchronous shutter that momentarily closes at successive time spacings of shorter duration than the scanning period of the sensor. The amplified signal is converted to a digital signal and processed by a microcontroller and associated hardware and software. The detector automatically and periodically calibrates itself and compensates the temperature signals for any temperature difference between the ambient external temperature and the temperature inside the detector housing. The output signal may be digital or analog.

Abstract: Warning lights at a railroad grade crossing are energized at a predetermined flash rate when a train is approaching through the use of an essentially fail-safe solid state crossing controller employing circuitry that is active in creating an off condition of the warning lamps. A controller unit operates a pair of warning lamps alternately in synchronism with a warning rate (flash rate) signal having a predetermined repetition rate, such as 55 pulses per minute. When the crossing is safe, an RC circuit in the lamp driver responds to a 500 Hz safe status signal by providing continuous control excitation to a normally conductive lamp switching circuit to maintain the lamps deenergized. In a failure mode, the normal condition of the switching circuit maintains one lamp of each pair continuously energized.

Abstract: Overheated railroad journal bearings, wheels, and wheel components on a moving or stationary railroad train are detected by amplifying the current signal from an infrared radiation sensor comprising a pyroelectric cell. A reference temperature is sensed by chopping the incident infrared radiation with an asynchronous shutter that momentarily closes at successive time spacings of shorter duration than the scanning period of the sensor. The amplified signal is converted to a digital signal and processed by a microcontroller and associated hardware and software. The software comprises a free-running loop Main Program which is subject to several interrupts. The output signal may be digital or analog and is transmitted to remote signal processing equipment for further processing.

Abstract: An island circuit detects the presence of a train on a crossing island, and, in response, de-energizes a normally energized relay to activate a warning. A random signature signal is generated and transmitted through the rails from a transmitter to a receiver connected to the rails on either side of the island. If a train is present within the island, the wheels and axles form an electrical shunt, preventing the receiver from detecting the transmitted signal. The circuit employs solid state micro-electronic components and ancillary components, and embedded software for controlling and monitoring the circuit functions. The random signature signal is characterized by a relatively high voltage level but a low duty cycle on the order of ten percent, and has three variables: (1) frequency; (2) duration time of the pulse, or burst, of the signal; and (3) the delay between successive bursts. Each of the three variables randomly assumes any one of eight different discrete values.

Abstract: A railroad train moving along an approach to a grade crossing (or other location of interest) is detected by apparatus that is responsive to the change in effective track impedance caused by the moving shunt. A constant current AC signal is applied to the track adjacent the crossing, and the resulting voltage changed in amplitude and phase is picked off by a receiver on the opposite side of the crossing. Voltage and current information derived from these signals is inputted to a microcomputer which calculates the track impedance and determines whether or not a warning device or devices at the crossing should be activated. Such determination is made on a repetitive basis in accordance with a repeating program loop and stored in memory.

Abstract: The number of on-line locomotives of a consist is either reduced or increased by a manual control system that conserves fuel by throttling back trailing locomotives and operating the remaining locomotives of the consist at the most efficient throttle position. A control unit in the lead locomotive is operated by the engineer to command control units in equipped trailing locomotives of the consist. Each time the engineer depresses a "subtract power" push button, one trailing locomotive is throttled back; conversely, each time an "add power" push button is depressed, a trailing locomotive is returned on line by advancing its throttle to the most efficient position. A cutout control signal, which is generated in the lead locomotive and transmitted to trailing units in serial order (front to rear) by a single spare trainline wire, has voltage levels that progressively decrease or increase in response to the subtract or add power commands.