Patent US3716787A successfully refreshed from Google Patents.
US3716787A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for monitoring speed utilizing a tuned circuit whose phase changes in proportional to speed
Assignee: Westinghouse Air Brake Co
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Filing: 1970-11-27
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Granted: 1973-02-13
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Expires: 1990-11-27
Abstract
Abstract A motion detector system using a pulse tachometer comprising a wheel of non-magnetic, non-conductive material such as fiber or Teflon having a plurality of equally spaced magnetically distinct pins in the periphery which move into proximity of a pick-up coil of a tuned circuit to vary the impedance therein. Varying the impedance effects a circuit phase-shift which is compared with a predetermined reference phase of voltage and current in said circuit to provide an indication of any movement of the wheel and a measurement of the speed of movement in a measured time interval.
Inventors
- 👤 P Hammond
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 16:40
CPC Classifications
G; G01; G01P; G01P3/00; G01P3/42; G01P3/44; G01P3/48; G01P3/481; G01P3/488; G01P3/489
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
149 words
Speed detector apparatus comprising in combination: a. a tuned circuit including a coil and a capacitor, b. oscillator means for supplying a fixed frequency excitation signal at the input of said tuned circuit, c. speed responsive means comprising: i. a non-magnetic, non-conductive rotatable disc member arranged with the periphery thereof in close relationship with said coIl, and ii. a plurality of magnetically distinct pin means spaced around the periphery of said disc member to vary the inductance of said tuned circuit in accordance with the presence or absence of a pin in proximity with said coil to effect a leading or a lagging phase shift in the output of said tuned circuit relative to said resonant frequency thereof, and d. comparison means subject to said fixed frequency excitation signal and the output of said tuned circuit for detecting said leading or lagging phase shift of said tuned circuit output.
Claim 2
Dependent Claim
149 words
Speed detector apparatus comprising in combination: a. a tuned circuit including a coil and a capacitor, b. oscillator means for supplying a fixed frequency excitation signal at the input of said tuned circuit, c. speed responsive means comprising: i. a non-magnetic, non-conductive rotatable disc member arranged with the periphery thereof in close relationship with said coIl, and ii. a plurality of magnetically distinct pin means spaced around the periphery of said disc member to vary the inductance of said tuned circuit in accordance with the presence or absence of a pin in proximity with said coil to effect a leading or a lagging phase shift in the output of said tuned circuit relative to said resonant frequency thereof, and d. comparison means subject to said fixed frequency excitation signal and the output of said tuned circuit for detecting said leading or lagging phase shift of said tuned circuit output.
Claim 3
Dependent Claim
149 words
Speed detector apparatus comprising in combination: a. a tuned circuit including a coil and a capacitor, b. oscillator means for supplying a fixed frequency excitation signal at the input of said tuned circuit, c. speed responsive means comprising: i. a non-magnetic, non-conductive rotatable disc member arranged with the periphery thereof in close relationship with said coIl, and ii. a plurality of magnetically distinct pin means spaced around the periphery of said disc member to vary the inductance of said tuned circuit in accordance with the presence or absence of a pin in proximity with said coil to effect a leading or a lagging phase shift in the output of said tuned circuit relative to said resonant frequency thereof, and d. comparison means subject to said fixed frequency excitation signal and the output of said tuned circuit for detecting said leading or lagging phase shift of said tuned circuit output.
Claim 4
Dependent Claim
149 words
Speed detector apparatus comprising in combination: a. a tuned circuit including a coil and a capacitor, b. oscillator means for supplying a fixed frequency excitation signal at the input of said tuned circuit, c. speed responsive means comprising: i. a non-magnetic, non-conductive rotatable disc member arranged with the periphery thereof in close relationship with said coIl, and ii. a plurality of magnetically distinct pin means spaced around the periphery of said disc member to vary the inductance of said tuned circuit in accordance with the presence or absence of a pin in proximity with said coil to effect a leading or a lagging phase shift in the output of said tuned circuit relative to said resonant frequency thereof, and d. comparison means subject to said fixed frequency excitation signal and the output of said tuned circuit for detecting said leading or lagging phase shift of said tuned circuit output.
Claim 5
Dependent Claim
36 words
Speed detector apparatus, as recited in claim 1, further comprising means for registering the frequency of detection of said leading or lagging phase shift as an indication of the speed of rotation of said disc member.
Claim 6
Dependent Claim
89 words
Speed detector apparatus, as recited in claim 1, further characterized in that said comparison means comprises: a. signal modifying means for amplifying and shaping said phase shifted output of said tuned circuit, and b. a bistable flip-flop device having a first input subject to said modified output of said phase shifted signal, a second input subject to said excitation signal of said oscillator means and an output provided so long as said first input is present at the transition of said excitation signal from one digital state to another.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-02-13 | 1976-08-14 | 1977-02-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-02-13 | 1980-08-14 | 1981-02-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-02-13 | 1984-08-14 | 1985-02-13 | $7700.00 | Window Closed / Lapsed |