US3699563A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Wheel slip detector
Assignee: Canadian National Railway Co
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Filing: 1969-11-25
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Granted: 1972-10-17
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Expires: 1989-11-25
Abstract
Abstract The fact that one drive axle of a railway locomotive is rotating faster than another due to ''wheel slip'' of the wheels on the faster driving axle is detected by the circuitry of this invention. The rotation of each of two or more drive axles is caused to generate a cyclically varying signal which cyclic variation includes a frequency proportional to the rotational speed of the drive axle. The circuitry provides a signal whose magnitude varies as such frequency and the magnitudes of such signals are compared with each other to obtain an indication of wheel slip of an undesirable amount. A power supply and associated circuitry are provided for deriving from the locomotive supply potentials for operating the electronic circuitry of the wheel slip detector. Such power supply is arranged to eliminate the effects of voltage surges and fluctuations from the locomotive supply, to create alternating current from the direct current supply, transform such current, rectify and regulate it. Such supply is useful for the wheel slip detector circuitry and for other electrical functions.
Inventors
- 👤 George R Cass
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 20:46
CPC Classifications
B; B60; B60L; B60L3/00; B60L3/10; B60L2200/00; B60L2200/26
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
322 words
A wheel slip detector comprising a plurality of means, each responsive to the rotation of the locomotive drive axle of an independently mounted locomotive drive wheel slippage of which is to be detected, for producing a corresponding plurality of cyclically varying signals each having a frequency proportional to the rotational speed of the corresponding said axle, means for deriving a like plurality of further signals from said cyclically varying signals each of which is indicative of the corresponding said frequency; and means for comparing said further signals and for producing an output when the difference between the least of said further signals and the greatest of said further signals exceeds a predetermined value, said means for deriving said further signal indicative of frequency comprising means for deriving from said cyclically varying signal, a square wave of frequency varying with said rotation, means for differentiating said square wave to produce pulses, means responsive to such pulses of one sense to produce pulses of substantially equal duration, means responsive respectively to said pulses of substantially equal duration to produce pulses of such duration and substantially constant amplitude, and means responsive to said last mentioned pulses for producing a voltage of magnitude proportional to the frequency of said last mentioned pulses, said means for producing square waves comprising means responsive to axle rotation for producing a periodically varying signal having variations of a frequency proportional to axle rotational frequency, means for amplifying the last mentioned signal, and means for developing from the amplified signal, a square wave of frequency corresponding to said amplified signal, said amplifying means comprising an amplifier having its input connected to said square wave developing means, said amplifier being provided with a negative feedback line connecting said output to said input, said feedback line having parallel diodes poled in opposite polarity, each diode being selected to require a predetermined voltage drop across it in its poled conducting direction before conduction commences.
Claim 2
Dependent Claim
322 words
A wheel slip detector comprising a plurality of means, each responsive to the rotation of the locomotive drive axle of an independently mounted locomotive drive wheel slippage of which is to be detected, for producing a corresponding plurality of cyclically varying signals each having a frequency proportional to the rotational speed of the corresponding said axle, means for deriving a like plurality of further signals from said cyclically varying signals each of which is indicative of the corresponding said frequency; and means for comparing said further signals and for producing an output when the difference between the least of said further signals and the greatest of said further signals exceeds a predetermined value, said means for deriving said further signal indicative of frequency comprising means for deriving from said cyclically varying signal, a square wave of frequency varying with said rotation, means for differentiating said square wave to produce pulses, means responsive to such pulses of one sense to produce pulses of substantially equal duration, means responsive respectively to said pulses of substantially equal duration to produce pulses of such duration and substantially constant amplitude, and means responsive to said last mentioned pulses for producing a voltage of magnitude proportional to the frequency of said last mentioned pulses, said means for producing square waves comprising means responsive to axle rotation for producing a periodically varying signal having variations of a frequency proportional to axle rotational frequency, means for amplifying the last mentioned signal, and means for developing from the amplified signal, a square wave of frequency corresponding to said amplified signal, said amplifying means comprising an amplifier having its input connected to said square wave developing means, said amplifier being provided with a negative feedback line connecting said output to said input, said feedback line having parallel diodes poled in opposite polarity, each diode being selected to require a predetermined voltage drop across it in its poled conducting direction before conduction commences.
Claim 3
Dependent Claim
210 words
A wheel slip detector comprising a plurality of means, each responsive to the rotation of the locomotive drive axle of an independently mounted locomotive drive wheel slippage of which is to be detected, for producing a corresponding plurality of cyclically varying signals each having a frequency proportional to the rotational speed of the corresponding said axle, means for deriving a plurality of further voltage signals from said cyclically varying signals each of which is indicative of the corresponding said frequency; and means for comparing the least of said further signals and the greatest of said further signals and for producing an output when the difference between the least of said further signals and the greatest of said further signals exceeds a predetermineD amount, said comparing means comprising a like plurality of pairs of transistors, means for connecting said voltage signals to the base electrodes of the transistors of said pairs of transistors, means for commonly connecting one transistor of each of said pairs of transistors produce a voltage signal substantially equal to the lowest of said voltage signals and means for commonly connecting each of the other transistors of each pair of said pairs of transistors to produce a voltage signal substantially equal to the highest of said voltage signals.
Claim 4
Dependent Claim
210 words
A wheel slip detector comprising a plurality of means, each responsive to the rotation of the locomotive drive axle of an independently mounted locomotive drive wheel slippage of which is to be detected, for producing a corresponding plurality of cyclically varying signals each having a frequency proportional to the rotational speed of the corresponding said axle, means for deriving a plurality of further voltage signals from said cyclically varying signals each of which is indicative of the corresponding said frequency; and means for comparing the least of said further signals and the greatest of said further signals and for producing an output when the difference between the least of said further signals and the greatest of said further signals exceeds a predetermineD amount, said comparing means comprising a like plurality of pairs of transistors, means for connecting said voltage signals to the base electrodes of the transistors of said pairs of transistors, means for commonly connecting one transistor of each of said pairs of transistors produce a voltage signal substantially equal to the lowest of said voltage signals and means for commonly connecting each of the other transistors of each pair of said pairs of transistors to produce a voltage signal substantially equal to the highest of said voltage signals.
Claim 5
Dependent Claim
66 words
A wheel slip detector as claimed in Claim 2 wherein a power electrode of each said one transistor is connected to a first common conductor and a power electrode of each said other transistor is connected to a further common conductor, and wherein said last named means further comprises a differential amplifier having first and second inputs connected to said first and further common conductors, respectively.
Claim 6
Dependent Claim
173 words
A wheel slip detector comprising a plurality of means, each responsive to the rotation of the locomotive drive axle of an independently mounted drive wheel slippage of which is to be detected, for producing a corresponding plurality of cyclically varying signals each having a frequency proportional to the rotational speed of the corresponding said axle, means for deriving a like plurality of further signals from said cyclically varying signals each of which is indicative of the corresponding frequency, said further signal deriving means including amplifier means for amplifying said cylically varying signals, said amplifier means including negative feedback line connected between the output and input thereof and comprising a pair of oppositely poled diodes connected in parallel for detecting deflections in a said cyclically varying signal of a predetermined amplitude; and means for comparing the least of said further signals and the greatest of said further signals and for producing an output when the difference between the least of said further signals and the greatest of said further signals exceeds a predetermined amount.
Claim 7
Dependent Claim
173 words
A wheel slip detector comprising a plurality of means, each responsive to the rotation of the locomotive drive axle of an independently mounted drive wheel slippage of which is to be detected, for producing a corresponding plurality of cyclically varying signals each having a frequency proportional to the rotational speed of the corresponding said axle, means for deriving a like plurality of further signals from said cyclically varying signals each of which is indicative of the corresponding frequency, said further signal deriving means including amplifier means for amplifying said cylically varying signals, said amplifier means including negative feedback line connected between the output and input thereof and comprising a pair of oppositely poled diodes connected in parallel for detecting deflections in a said cyclically varying signal of a predetermined amplitude; and means for comparing the least of said further signals and the greatest of said further signals and for producing an output when the difference between the least of said further signals and the greatest of said further signals exceeds a predetermined amount.
Claim 8
Dependent Claim
90 words
A detector as claimed in Claim 4 wherein said further signal deriving means comprises monostable multivibrator means for converting pulses derived from a said cyclically varying signal into corresponding control pulses of a precise predetermined pulse width, said multivibrator means including a first transistor whose off time determines the pulse width of the control pulses, timing network means for controlling the off time of said first transistor and a second transistor having the emitter-collector circuit thereof connected to the base of said first transistor for compensating for variations in temperature.
Claim 9
Dependent Claim
76 words
A method as claimed in Claim 24 wherein said step of eliminating voltage transients includes connecting a Zener diode across the locomotive direct current output lines poled to conduct at low voltage from the negative to the positive line and to conduct at a predetermined higher voltage from the positive to the negative line, said Zener diode being selected in relation to the voltage on said output lines so that said Zener diode is continuously conducting.
References Cited (Backward Citations)
US2735090A
Cited
US3146432A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-10-17 | 1976-04-17 | 1976-10-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-10-17 | 1980-04-17 | 1980-10-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-10-17 | 1984-04-17 | 1984-10-17 | $7700.00 | Window Closed / Lapsed |