Abstract: A method and apparatus are disclosed for sensing the temperature of bearings of vehicles traveling along a track, the apparatus including a linear-array infrared detector positioned adjacent to the track. The output from the linear-array infrared detector is scanned at a scanning rate that is regulated according to the vehicle's velocity, and this output is compared to predetermined thresholds to indicate excessive heat produced by the wheels and/or bearings.

Abstract: In a device for detecting excessively heated components or locations in moving objects, in particular in moving rail vehicles, such as bearings, brakes and/or wheel rims, having at least one infrared beam detector (7) and optical devices for representing the image of the measuring point on the infrared beam detector (7), a separate lens (1, 2) is aimed toward each measuring point, which focuses the image of the measuring point on different points (4, 5) of an image-correcting system (3), and a scanning device (9), which periodically picks up the measuring beams, is disposed between the image-correcting system (3) and the detector (7) and focuses the measuring beams onto the detector (7) which is common to all measuring points.

Abstract: A detector apparatus uses two scanners on the right of way for monitoring the wheels of a moving train . The scanners scan the wheels transversely to the tracks along a common axis and generate wheel temperature signals. The signals corresponding to the wheel bearing end caps or housing lids indicative of the wheel bearing temperatures are separated and analyzed so that the apparatus can detect and indicate both hot wheel and hot bearing conditions.

Abstract: An on-board hot bearing detector system includes a microprocessor and heat sensors mounted on the train cars for sensing the bearing temperatures. Diagnostic circuitry is also provided to monitor the sensors and detect if a sensor is open or short. Additionally, the train line is controlled by the microprocessor and is provided with a current limiting device for protection against large currents in case of a short.

Abstract: A frequency generating circuit and a cap-freeing mechanism in a bolt are responsive to a longitudinal movement of a piston in response to overheating of an associated bearing. The cap-freeing mechanism transfers a force from the piston to a cap, thereby freeing the cap from a head portion of the bolt and allowing an antenna to extend to the outside of the bolt. The frequency generating circuit is activated by a connection made between a switch and a battery of the circuit by the piston. Upon becoming activated, the frequency generating circuit sends a predetermined frequency or frequency pattern through the antenna.

Abstract: Heaters are used to simulate wheel bearings at specified temperatures. Two heaters are mounted on each side of a railroad test car. The heaters are mounted on the sprung carriage of the car to reduce vibration of the hardware and avoid interfering with wheel trucks on the car. Ambient temperature sensors are similarly mounted. Wire brushes are mounted below the heaters and sensors to activate magnetic wheel flange sensors. The heaters are controlled by a system which is integrated with a hot wheel simulator system.

Abstract: A monitor to diagnose wheel assemblies of passing railroad trains, the monitor being characterized in that a cavity is present in and parallel to a measurement tie or in a hollow railroad tie, the cavity housing infrared deflection units and at least one infrared detector which make it possible to monitor all heat sources present in the vicinity of the wheel assembly and the undercarriage of the train car while offering maximum protection against mechanical and electrical factors. The wheel pressure and accelerator pickups introduced with the monitor allow accurate determination of the values needed to normalize the infrared test results such as wheel position, wheel weight and tread conditions.

Abstract: A communication system for submitting RF signals responsive to the currents of defects or hazards in a railway system wherein a reserve cell ampule containing an electrolyte is disposed in one compartment of a housing and the electronic apparatus transmitting desired signals is disposed in a second compartment such that when the reserve cell is heated the pressure rises within the ampule to rupture it, whereby the electrolyte contained is dispersed in the first compartment and causes energization of electronic apparatus including an antenna connected to such apparatus, whereby the antenna is ejected from the housing and is able to broadcast suitable RF signals.

Abstract: A temperature sensor assembly for monitoring railroad car wheels includes an array of temperature detectors arranged to generate a temperature profile of the wheel. The array may be formed integrally with imaging elements and signal conditioning elements on a single IC chip. The assembly may be arranged to monitor the wheel either transversely or in parallel to the direction of wheel movement.

Abstract: The present invention relates to an alarm system suitable for use in warning of overheating in rotatable bearings 4 having first and second bearing portions. The alarm system comprises an alarm signal generator means having a thermally activated engagement element 8 on a first bearing portion or body 6 connected thereto. The element 8 is in thermal connection with the bearing 4 and is formed and arranged so as to be driven from a first primed retracted position into a second deployed extended alarm position upon reaching a predetermined temperature. In the alarm position the element 8 contacts an engaging portion 12 on the second bearing portion so as to produce a distinctive alarm signal indicating that said bearing 4 has exceeded the predetermined temperature.

Abstract: A temperature warning device for indicating when a threshold temperature has been exceeded includes a threaded bolt having a bolt head and a bolt body. The bolt head and bolt body have a longitudinal bore defined by a surrounding surface with the bore having a closed end and an open end at the bolt head. A plunger in the bore has a plunger head and a plunger body terminating at the open end of the bore. A retaining cap is secured in the bore of the bolt head and has a cap hole through which the plunger body freely extends. A sleeve of a fusible material is contained in the bore which melts at the threshold temperature. This sleeve substantially fills a volume of the bore radially between the plunger body and the surrounding surface of the bore and longitudinally between the plunger head and the cap. A compressed spring is located in the bore between the closed end and the plunger head.

Abstract: In a process for measuring axle bearing temperatures in order to locate hot wheels in moving railroad cars with infrared receivers and with an oscillating scanning beam that is oriented transversely to the longitudinal direction of the rail, the analog measured values from the infrared receiver are digitized and then coupled with the oscillation frequency orientation of the scanning beam so that at least two complete oscillations of the scanning beam are analyzed for each axle. A mean value is formed from the measured value corresponding to one sub-area of a first oscillation of the scanning beam and from the measured value that corresponds to subsequent oscillations of the scanning beam. When this is done, the calculation of the average or mean value is repeated for a specific predetermined maximum number of oscillations of the scanning beam and for as long as an activation signal initiated by the wheel signals from the same axle is within the measuring angle of the center.

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: A hot bearing simulator is provided for verifying the proper operation of hot box detectors in a dynamic fashion. The hot bearing simulator employs a temperature controller and heater means associated with various axles of a rolling carriage. The heaters are adjusted such that a hot box detector will be verified to determine if it is able to sense when the absolute temperature of left or right wheel bearings exceeds a first predetermined temperature or, alternatively, when the difference in temperature between a left and right wheel bearing differ by a second predetermined amount.

Abstract: Auto-correlation techniques are employed to monitor railway care wheel bearings. Three successive bearing temperatures A, B and C are measured and those two temperatures that are the closest in value determined. The least of these is used as a reference to be multiplied by a constant and thereby define a limit value which when exceeded generates an alarm signal.

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: A hot bearing simulator is provided for verifying the proper operation of hot box detectors in a dynamic fashion. The hot bearing simulator employs a temperature controller and heater means associated with various axles of a rolling carriage. The heaters are adjusted such that a hot box detector will be verified to determine if it is able to sense when the absolute temperature of left or right wheel bearings exceeds a first predetermined temperature or, alternatively, when the difference in temperature between a left and right wheel bearing differ by a second predetermined amount.

Abstract: A thermal sensor composed of a standard bolt which has been modified to embody a temperature sensing element and placed into a bearing assembly of a train. This element contains a heat-sensitive wax that at a preset temperature expands causing the motion of a piston which exposes projections. The projection may function as an antenna either passive (reflective) or active (transmitter) that can be probed from the wayside with very high selectivity.

Abstract: A gating circuit and method for controlling the output of data from the scanner of a heat detector in response to a bi-polar signal indicating the presence of an object within the scanning window of the heat detector; stores the data output; senses the stored data with respect to a reference signal with a differential amplifier responsive to the data output; gates the data output to storage by a first gate interconnecting the data output with the differental amplifier; generates control signals for opening and closing the gate with different states of the bi-polar signal for controlling the gate such that the reference signal represents the last immediate data output; detects the difference between the stored peak value and the highest data value of the output data subsequent to turning off a first gate; and using a second gate interconnecting the output of the sensor with the detector and controlled by the control signals to be open with the first gate closed and closed with the first gate open.

Abstract: A hot box detector system is provided wherein heat signals from bearings within a housing are analyzed to determine if the scanned surface of the housing is an inner sidewall surface or an outer sidewall surface. The signals are normalized to account for differences in the heat dissipating characteristics of the inner and outer sidewalls and air stream cooling resulting from the trains movement.

Abstract: Hot-box signalling devices are disclosed for indicating the presence of overheated bearings in vehicles such as rail cars. The device includes means defining a closed compartment containing a fluid and pressure-sensitive means communicating with the compartment. The compartment is arranged in thermal communication with a bearing of the vehicle so that increases in the temperature of the bearing cause increases in the pressure exerted by the fluid. The pressure-sensitive means is adapted to produce a signal when the pressure exerted by the fluid exceeds a predetermined threshold representing an over-temperature condition in the bearing. Preferably, the pressure-sensitive means takes the form of a plug normally closing an opening in the compartment, and a marker material, the plug and marker material being expelled when the pressure in the compartment reaches said predetermined threshold. In one aspect of the invention, provision is made to compensate for ambient temperature.

Abstract: A train monitoring system for detecting hot boxes, dragging equipment and the like at the rail site, determining the location on the train of a monitored defect and annunciating the defect and location from a digital automated voice generator to the train crew as well as along a telephone line to a central location. Recording of the defect with time and date of same is provided. The system also has provision for self check via an external simulated train.

Abstract: A speed independent system is used for obtaining a preselected number of samples from an object moving along a fixed path, such as a railroad train passing through a sensing zone along the section of track. The sensing zone is defined by a pair of wheel sensors. Upstream of the sensing zone a third sensor is positioned. The distance between the third sensor and the closer of the pair of sensors comprises a reference distance which is the length of the sensing zone multiplied by a known multiple. The time for the train to pass through the reference distance is obtained and then divided by a divisor comprising the product of the known multiple and the desired number of samples to obtain a single interval. During the time the train passes through the sensing zone consecutive intervals are counted off to obtain the desired number of samples.

Abstract: A railroad car hot box detector system is provided which includes a variable circuit means for processing the heat signal generated by an infra-red detector viewing a sensing zone along a section of track. The system includes a conditioning circuit which determines one or more conditions of the train (such as the wheel speed or temperature of the car bottom) and uses that information to vary the processing circuit to enable the heat signal to be processed optimally for the detected condition.

Abstract: In a method for advance indication of the possibility of damage occurring to wheel bearings of vehicles, particularly railroad vehicles, the temperatures of the wheel bearing sets of a plurality of wheels are monitored by temperature detectors fixedly mounted on the vehicle. A determined value is derived from the measured values of temperature, and this determined value is compared with the temperature of a further temperature detector, in order to produce a warning signal. The warning system is incorporated in the vehicle itself, and provides a warning to the vehicle personnel.

Abstract: An improved method and circuit is provided for processing waveforms from a railway car heat signal to eliminate spurious signals and to differentiate between roller bearings and friction bearings in a railroad hot box detector system. The waveforms generated by passing bearings are discretely sampled and spurious signals are eliminated by considering only those signals that fall within the crossing points of a threshold value. Discrimination between roller bearings and friction bearings is obtained by determining the ratio of the sum of the discrete values of the amplitude of the waveform within a first set of samples between the crossing points to the sum of the discrete values of the amplitude of the waveform within a second set of samples between the crossing points.

Abstract: An apparatus for the thermal monitoring of railway wheels is provided. The monitor comprises an insert placed into the railway wheel near its rim. If the wheel overheats, the monitor will be released from its location. A subsequent inspection will readily indicate that the wheel has been overheated during operation.

Abstract: A warning indicator including a housing attachable to the wheel and axle assembly of a railway car. An ejector assembly in the housing is spring biased to deploy a visual indicator in the presence of abnormal bearing temperatures. A fusible retainer, upon being subjected to abnormal temperatures, releases a stem of the ejector assembly which carries a visible indicator, such as a streamer, outwardly into the airstream for display in a highly visible manner. The indicator housing is provided with tool receiving surfaces to facilitate indicator installation and removal.

Abstract: An improved circuit is provided for differentiating between roller bearings and friction bearings in a railroad hot box detector system. The improved circuit integrates the waveform generated by a bearing scanner and compares that to the integral of a pre-selected portion of the waveform. By this method of comparison, irregularities in the system due to noise are obviated.

Abstract: An apparatus for determining the temperature of railroad car wheel journals (i.e., "hotbox" detector) includes a sensor including a pyroelectric cell responsive to infrared radiation signals, which are focused onto the cell, to output voltage signals as a function of the radiation signals inputted thereto. The sensor exhibits a nonlinear gain response to different frequencies of input signals and compensation is provided by coupling the output of the sensor to a differentiating circuit which has a similar but relatively negative gain response. The output of the differentiating circuit is a substantial voltage replica of the infrared input signal and this voltage signal may be applied to a suitable utilization device such as one which records journal temperature and/or provides a suitable alarm when a sensed journal temperature exceeds a predetermined value.

Abstract: A normally inactive sound signal generator is supported from the rotatable axle of each railway car in a train and actuatable to generate a predetermined signal in response to a hot box condition. Electrically operable signal receivers coupled to electrically operable radio signal transmitters are spaced along the railroad track at predetermined intervals which may be 4,000 to 6,000 feet apart and the receivers and transmitters are operable on low magnitude current, such as provided in the rails of the track for Centralized Train Control Systems.

Abstract: A system for each car of a railway train for detecting a hot journal box or boxes on the car by utilizing the heat of the overheated journal box to produce electrical current which, when a sufficient degree is transmitted through appropriate electrical devices to an explosive bolt placed in the brake pipe, causes the bolt to be exploded and thereby open a vent in the brake pipe to atmosphere to effect a brake application on the train. The sound of the escaping air from the brake pipe is used to determine the particular car on which the overheated journal box is located.

Abstract: An anti-derailment system to prevent train derailment due to axle failure sulting from journal bearing overheating includes a thermal sensor to continuously monitor the temperature of the bearing and to activate the brake system when the temperature exceeds a predetermined level. A thermally-responsive element located in the journal bearing adapter physically deforms to activate a power source. The resulting signal initiates an electroexplosive brake line venting mechanism, puncturing and venting the brake line to stop the train. Several configurations of the thermal sensor and the power source are possible.