Abstract: Improvements relating to railroad telemetry and control system address problems in compatibility between HOT and EOT units, implement an automatic UDE location procedure, and automate calibration of EOT units. An improved two way protocol that allows EOT units having different code formats to be used with a HOT unit. A method is implemented by a HOT unit, cooperating with an EOT unit, for locating a fault which causes a UDE brake operation. An automatic calibration procedure for the EOT unit that does not require the operator to have access to the electronic circuitry.

Abstract: Power supply for an EOT unit in which an electrical generator driven by air from the train air brake pipe provides the primary power to the EOT unit. The power supply of this invention may be incorporated as part of the EOT unit or it may be supplied as a power kit modification for existing EOT units in order to replace electric storage batteries in these units.

Abstract: A solid state event recorder having particular application to railroad locomotives has a plurality of interface modules to allow the collection of desired data over a period of time. Radio downloading of the data provided by a telemetry transmitter to wayside receivers is the primary way of downloading data. Alternate data downloading are provided by a removable memory module, a portable wireless data extractor and a laptop computer. The removable memory module is provided with its own backup battery power supply but normally derives its power from an inductive coupling to the solid state recorder. Data is read into the removable memory module from the solid state recorder via an inductive coupling, and data is read out of the removable memory module to the telemetry transmitter via another inductive coupling. Both the portable wireless data extractor and the laptop computer are used for maintenance purposes.

Abstract: A solid state speed indicator for railroad locomotives is provided with a plurality of indications in addition to speed. These include an acceleration indicator and an overspeed indicator. In addition, the speed indicator is provided with a dual range speed function having at least one particular use in drag operations. A variation of the solid state speed indicator is a retrofit design that replaces the meter movement in existing speed indicator equipment with a solid state display.

Abstract: A railroad brake pressure recorder for use with both analogue and digital break pressure manifolds monitors the signal on its analogue air brake pressure input connector. If the signal on this input exceeds a predetermined frequency, inputs are processed as coming from an analogue manifold. If it is less than this frequency, the inputs are processed as coming from a digital manifold.

Abstract: A solid state event recorder having particular application to railroad locomotives has a plurality of interface modules to allow the collection of desired data over a period of time. Radio downloading of the data provided by a telemetry transmitter to wayside receivers is the primary way of downloading data. Alternative data downloading are provided by a removable memory module, a portable wireless data extractor and a laptop computer. The removable memory module is provided with its own backup battery power supply but normally derives its power from an inductive coupling to the solid state recorder. Data is read into the removable memory module from the solid state recorder via an inductive coupling, and data is read out of the removable memory module to the telemetry transmitter via another inductive coupling. Both the portable wireless data extractor and the laptop computer are used for maintenance purposes.

Abstract: An EOT emergency arming apparatus and method in which an engineer at the HOT operates a standard air brake control and responds to a resulting report of change in air pressure from the EOT within a prescribed short interval. The response is a signal which includes the EOT unique identification code, and if received within the short interval is interpreted by the EOT as if the EOT ARM switch had been activated.

Abstract: A motor driven ball valve may be driven in two modes of operation; those modes are a normal or testing mode and an emergency mode. The ball valve, when in its full open position, has an air passage that allows for the rapid exhaust of air in the air pipe of the air brake system to atmosphere, thereby inducing the emergency application of the brakes. The rotating ball valve assembly is capable of infinite variation between its full closed and its full open positions. Thus, the motor drive, which is remotely controlled, can effectively modulate the reduction in air pressure in the air pipe for a variety of purposes, including normal operation of the brakes and testing the air brake system. The motor drive mechanism may be in a cam, gear, or follower configuration. When an emergency application of the brakes is required, the motor drive mechanism is disengaged to allow a spring or other torsion device to rapidly rotate the ball to full open position, while drawing minimal electrical power.

Abstract: An improved timer circuit for engineman monitoring devices allows a "drag operation" without frequent operation of the audio/visual alarms of the monitoring devices. The circuit receives an input from an existing switch in the locomotive to select the drag input state, but this input state does not necessarily select a longer time period for the reset window. More particularly, if drag is off and the speed is between approximately 1/3 and 31/2 mph, the timeout period is long (e.g., 123 seconds), but if drag is on for this speed, the timeout period is doubled (e.g., 246 seconds). Over 31/2 mph, the state of the drag switch is ignored, and the timeout period is long until a predetermined speed is reached and thereafter decreases with increasing speed. In addition, at "zero" speed, i.e., below 1/3 mph, the timeout period is reduced to 20 seconds to prevent defeat of the system by tampering with the axle drive wires.

Abstract: A fuel measuring system of the bubble type is adaptable for use with a plurality of tanks of predetermined differing geometries. The system employs at least two bubbling tubes located at predetermined locations in a tank. A predetermined volume flow of air is made to pass through each tube. Pressure transducers are used to periodically measure the air pressures supplied to the bubbling tubes. Temperature is also periodically sampled, and the pressure and temperature data is used by a microprocessor to make the necessary computations to first determine the averaged normalized air pressure and then the height of the fuel in the tank. In order to correlate the computed value of fuel height with the actual quantity of fuel in the tank, the microprocessor accesses data in a table lookup memory for the particular tank and performs calculations in order to derive the instantaneous volume of fuel in the tank.

Abstract: A gravity operated switching circuit, having particular application in end of train equipment, allows the microprocessor circuit board in the equipment to be turned off. The circuit turns the power off when the equipment is laid on its side after a predetermined time constant, and when the equipment is again mounted in an upright position, the power is turned on after a different predetermined time constant. A modification of the basic circuit requires a reset button to be manually pressed to restore power after the equipment is again mounted in an upright position.

Abstract: An anti-stall motor drive circuit for a very slow running permanent magnet d.c. motor is disclosed. The slow running speed of the motor sometimes allows an insulating film to build up between the brushes and the commutator which causes the stalled condition. The motor (10) is connected in the collector circuit of a drive transistor (Q1) which has a current limiting resistor (R9) connected in its emitter circuit. A stalled condition of the motor (10) is sensed by a lack of output from a tachometer (16) output. The output of the tachometer is full wave rectified by an operational amplifier (22) and diodes (CR1 and CR2). The rectified tachometer voltage is applied to an integrator (24 and C1) having a clamping diode (CR7) connected in its feedback circuit. A zero output from the rectifier allows the integrator output to ramp up to a limiting value determined by the clamping diode.

Abstract: An improved automatic train-line air brake pressure monitoring system includes circuits that emulate an automatic brake valve and cause an automatic brake manifold release whenever a four psi increase in pressure is sensed. The system includes a pressure sensor amplifier (10) which provides a signal proportional to the sensed pressure in a brake pipe. This signal is tracked by a peak hold circuit (12) that stores the peak value of the signal. The output of the sensor amplifier is subtracted from the output of the peak hold circuit in a subtractor (14) to provide a difference signal. The difference signal is tracked by a reduction hold circuit (22) which stores the minimum value of the difference output from the subtractor. An increase in measured pressure from the stored minimum value is compared in a comparator (24) with a reference value representing the four psi level, and when the increased pressure exceeds the reference value, a system reset is generated.

Abstract: A marker light using an array (2) of light emitting diodes (12) in combination with lenses (3) provides a light beam of required intensity, shape and color for railroad applications. The light emitting diodes are arranged in various configurations to form the array (2). The lenses may be Fresnel lenses. Control circuitry (C) energizes the light emitting diodes at predetermined or variable flashing rates. Sensing circuitry (222) senses the failure of light emitting diodes in the array and provides an indication of such failure.

Abstract: An improved attaching device is provided for securely mounting railroad signalling and monitoring equipment (10, 12) on the coupler (36) of a railroad car. A package including a supporting frame (22) to which the equipment is fastened by a draw pull (16) rests on the top surface of the coupler. The supporting frame includes a mounting bracket (32) having an integral rod (50) which extends through the flag hole in the coupler knuckle. The end of the rod projects beyond the bottom of the coupler so that it can be secured. In the second embodiment (FIGS. 8 and 9), the rod (111) has bifurcated extensions (116, 118) which serve to strengthen the supporting frame (80). This embodiment also includes shock absorbing elements (108, 110 and 122). In a third embodiment, a post (162) slidably carries a shaft or rod (188) that is retractable into a locking position with the coupler. A crank (176) is used to retract the shaft into a locking position.