Detection of overheated railroad wheel and axle components
First Claim
1. A method of detecting an overheated component of a railroad train, comprising the steps of:
- (a) at a trackside location, scanning a passing component with an infrared sensor during a scanning period;
(b) momentarily preventing any infrared radiation from said component from impinging on said sensor to thereby establish a reference temperature;
(c) repeating said step (b) at successive time spacings each shorter in duration than said period; and
(d) comparing the response of said sensor when infrared is received to the response of the sensor at said time spacings.
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Accused Products
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.
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Citations
18 Claims
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1. A method of detecting an overheated component of a railroad train, comprising the steps of:
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(a) at a trackside location, scanning a passing component with an infrared sensor during a scanning period; (b) momentarily preventing any infrared radiation from said component from impinging on said sensor to thereby establish a reference temperature; (c) repeating said step (b) at successive time spacings each shorter in duration than said period; and (d) comparing the response of said sensor when infrared is received to the response of the sensor at said time spacings. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. In apparatus for detecting an overheated component of a railroad train:
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a sensing unit adapted to be disposed at trackside and having an infrared sensing element and means for focusing incident infrared radiation from a passing component on said sensing element, a shutter movable between a normally open position and a closed position in which the shutter blocks radiation that would otherwise reach said sensing element via said focusing means so that the sensing element is subjected only to ambient heat, means responsive to said sensing element for producing a heat signal during a period in which the sensing element is scanning the passing component, drive means connected to said shutter for repeatedly momentarily closing the same at successive time spacings each shorter in duration than said period, and output means responsive to said heat signal for comparing its amplitude between said time spacings with its amplitude at said time spacings. - View Dependent Claims (9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
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Specification