Abstract: The present invention relates to bearing defect detectors and in particular to an acoustic system for detecting defects in the bearings of moving railroad cars and identifying the location of these defects.

Abstract: This invention relates to the testing of apparatus used for on-line acoustic detection of bearing defects, particularly in railroad applications. A loudspeaker on each side of the section of track, in response to a microprocessor, generates simulated acoustic signatures characteristics of various bearing defects. The microprocessor additionally sends corresponding simulated train speed signals to the apparatus. The invention monitors the apparatus for the appropriate alarm signal.

Abstract: An apparatus for the detection of impact frequencies in moving railway train bearings which are characteristic of bearing defects. The apparatus transduces acoustic vibrations of the bearings into an electrical signal and extracts an envelope modulated carrier frequency component from the electric signal. The envelope is extracted from the carrier frequency component and is analyzed by a bandpass filter. The bandpass filter includes a switch capacitor filter controlled by a master clock which, in turn, is controlled by train speed and/or direction sensors positioned along the track on which the train travels.

Abstract: This invention relates to apparatus for the detection of accustic impact frequencies, characteristic of bearing assembly failure during operation, which modulate an acoustic carrier frequency band. This apparatus allows for on-site or field application with high-level of ambient noise such as are present in railroad yards. This apparatus allows for early detection of such failures, so that a repair may be made before damaging heat build-up or catastrophic bearing failure occurs. Additionally, with sufficient early warning in railroad applications, a train may continue running to a railyard for convenient shop repair rather than expensive field repair.

Abstract: A system to permit the visual observation of objects moving along a fixed path. The object is viewed through a television camera which images the object through an optic axis bending element. The bending element is angularly rotated in a sawtooth manner with the slope of the sawtooth determined by the speed at which the object moves along the path so as to track the object to immobilize the scene viewed by the mirror.

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: 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: A quasi-doppler direction finder is provided wherein the alternate dipole elements are divided into two groups. Each of the groups is connected to an associated RF attenuator which is driven by a control signal 180.degree. out-of-phase from that for the other group. Commutation between dipoles occurs so that there is a 50% overlap of "on" time between adjacent dipoles. Switching for each dipole occurs when its associated modulating function passes through zero.