Patent US4227401A successfully refreshed from Google Patents.
US4227401A
Expired / Lapsed
US
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Surface elevation measuring apparatus
Assignee: United States Department of the Navy
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Filing: 1979-05-15
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Granted: 1980-10-14
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Expires: 1999-05-15
Abstract
Abstract A terrain probe for sensing the elevation of a terrain surface whose prof is being measured and followed. A two-phase induction motor will raise or lower the terrain probe in response to either an increase or decrease in the elevation of the terrain surface. A four arm bridge circuit, which has an arm enclosed within the terrain probe, in combination with a low frequency oscillator, a differential amplifier, and power amplifier generate a sinusoidal drive signal which controls the two-phase induction motor.
Inventors
- 👤 John C. McKechnie
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 20:43
CPC Classifications
G; G01; G01C; G01C7/00; G01B; G01B7/00; G01B7/004; G01B7/008; G01B7/012; G01B7/28; G01D; G01D5/00; G01D5/12; G01D5/125
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
254 words
A surface elevation measuring apparatus comprising in combination: terrain probing means for sensing the elevation of a terrain surface whose profile is being measured and followed; oscillating means, having first and second outputs for generating a sinusoidal reference signal having a predetermined frequency; bridge circuit means having a quartet of arms, with one of said arms being enclosed within said terrain probing means; and having a first input terminal connected to the first output of said oscillating means, a second input terminal connected to the second output of said oscillating means, a first output terminal, and a second output terminal for providing a first sinusoidal signal, having a fixed amplitude, and a second sinusoidal signal, having a variable amplitude, in response to said sinusoidal reference signal generated by said oscillating means; amplifier means having a first input connected to the first terminal output of said bridge circuit means, a second input connected to the second terminal output of said bridge circuit means, and an output for providing a sinusoidal drive signal whose amplitude is proportional to the difference between the amplitude of the first sinusoidal signal and the amplitude of the second sinusoidal signal provided by said bridge circuit means; and servo drive motor means having an input connected to the output of said amplifier, and a shift output effectively connected to said terrain probing means for raising or lowering said terrain probing means along a vertical axis above said terrain surface in response to the sinusoidal drive signal provided by said amplifier means.
Claim 2
Dependent Claim
254 words
A surface elevation measuring apparatus comprising in combination: terrain probing means for sensing the elevation of a terrain surface whose profile is being measured and followed; oscillating means, having first and second outputs for generating a sinusoidal reference signal having a predetermined frequency; bridge circuit means having a quartet of arms, with one of said arms being enclosed within said terrain probing means; and having a first input terminal connected to the first output of said oscillating means, a second input terminal connected to the second output of said oscillating means, a first output terminal, and a second output terminal for providing a first sinusoidal signal, having a fixed amplitude, and a second sinusoidal signal, having a variable amplitude, in response to said sinusoidal reference signal generated by said oscillating means; amplifier means having a first input connected to the first terminal output of said bridge circuit means, a second input connected to the second terminal output of said bridge circuit means, and an output for providing a sinusoidal drive signal whose amplitude is proportional to the difference between the amplitude of the first sinusoidal signal and the amplitude of the second sinusoidal signal provided by said bridge circuit means; and servo drive motor means having an input connected to the output of said amplifier, and a shift output effectively connected to said terrain probing means for raising or lowering said terrain probing means along a vertical axis above said terrain surface in response to the sinusoidal drive signal provided by said amplifier means.
Claim 3
Dependent Claim
109 words
A surface elevation measuring apparatus according to claim 1, wherein said terrain probing means comprises: a cylindrical housing of ferromagnetic material having an upper end wall, said upper end wall having a centrally located downwardly protruding member extending to a predetermined distance above the lower end of said cylindrical housing; a rim cap effectively attached to the lower end of said cylindrical housing, and having a centrally located circular perforation; a flexible diaphragm of ferromagnetic material located between the lower end of said cylindrical housing and said rim cap; and a surface sensor effectively attached to said flexible diaphragm and passing through the circular perforation of said rim cap.
Claim 4
Dependent Claim
46 words
A surface elevation measuring apparatus according to claim 2, wherein said surface sensor comprises: an elongated rod attached at one end to said flexible diaphragm; and a tip fastened to the end of said elongated rod that is opposite the end attached to said flexible diaphragm.
Claim 5
Dependent Claim
15 words
A surface elevation measuring apparatus according to claim 3, wherein said tip comprises a wheel.
Claim 6
Dependent Claim
18 words
A surface elevation measuring apparatus according to claim 1, wherein said terrain surface comprises a model board surface.
Claim 7
Dependent Claim
18 words
A surface elevation measuring apparatus according to claim 1, wherein said oscillating means comprises a low frequency oscillator.
Claim 8
Dependent Claim
22 words
A surface elevation measuring apparatus according to claim 1, wherein the predetermined frequency of said sinusoidal reference signal is four hundred hertz.
Claim 9
Dependent Claim
134 words
A surface elevation measuring apparatus according to claim 1, wherein said bridge cicuit means comprises: an electromagnetic coil enclosed within said terrain probing means, and having first and second leads protruding from said terrain probing means with the first lead thereof effectively connected to the first output of said oscillating means; a reference coil having a first lead connected to the second lead of said electromagnetic coil and a second lead connected to the second output of said oscillating means; and a potentiometer having a fixed resistance and a movable arm in slidable engagement therewith, with the fixed resistance of said potentiometer having a first input terminal effectively connected to the first output of said low frequency oscillator, and a second input terminal effectively connected to the second output of said low frequency oscillator.
Claim 10
Dependent Claim
64 words
A surface elevation measuring apparatus according to claim 1, wherein said amplifier means comprises: a differential amplifier having a first input connected to the first output terminal of said bridge circuit means, a second input connected to the second output terminal of said bridge circuit means, and an output; and a power amplifier having an input connected to the output of said differential amplifier.
Claim 11
Dependent Claim
20 words
A surface elevation measuring apparatus according to claim 1, wherein said servo drive motor means comprises a two-phase induction motor.
Claim 12
Dependent Claim
229 words
A surface contour measuring apparatus, comprising in combination: a terrain probe; an electromagnetic coil enclosed within said terrain probe, and having first and second leads protruding from said terrain probe; a low frequency oscillator having a first output connected to the first lead of said electromagnetic coil and a second output for generating a sinusoidal reference signal having a predetermined frequency; a potentiometer having a fixed resistance, and a movable arm in slidable engagement therewith, with the fixed resistance of said potentiometer having a first input terminal effectively connected to the first output of said low frequency oscillator, and a second input terminal effectively connected to the second output of said low frequency oscillator, and the movable arm of said potentiometer having an output terminal; a reference coil having a first lead connected to the second lead of said electromagnetic coil and a second lead connected to the second output of said low frequency oscillator; a differential amplifier having a first input connected to the output terminal of the movable arm of said potentiometer, a second input connected to the second lead of said electromagnetic coil, and an output; a power amplifier having an input connected to the output of said differential amplifier; and a servo drive motor having an input connected to the output of said power amplifier, and a shaft output effectively connected to said terrain probe.
Claim 13
Dependent Claim
229 words
A surface contour measuring apparatus, comprising in combination: a terrain probe; an electromagnetic coil enclosed within said terrain probe, and having first and second leads protruding from said terrain probe; a low frequency oscillator having a first output connected to the first lead of said electromagnetic coil and a second output for generating a sinusoidal reference signal having a predetermined frequency; a potentiometer having a fixed resistance, and a movable arm in slidable engagement therewith, with the fixed resistance of said potentiometer having a first input terminal effectively connected to the first output of said low frequency oscillator, and a second input terminal effectively connected to the second output of said low frequency oscillator, and the movable arm of said potentiometer having an output terminal; a reference coil having a first lead connected to the second lead of said electromagnetic coil and a second lead connected to the second output of said low frequency oscillator; a differential amplifier having a first input connected to the output terminal of the movable arm of said potentiometer, a second input connected to the second lead of said electromagnetic coil, and an output; a power amplifier having an input connected to the output of said differential amplifier; and a servo drive motor having an input connected to the output of said power amplifier, and a shaft output effectively connected to said terrain probe.
Claim 14
Dependent Claim
108 words
A surface contour measuring apparatus according to claim 11, wherein said terrain probe comprises: a cylindrical housing of ferromagnetic material having an upper end wall, said upper end wall having a centrally located, downwardly protruding member extending to a predetermined distance above the lower end of said cylindrical housing; a rim cap effectively attached to the lower end of said cylindrical housing, and having a centrally located circular perforation; a flexible diaphragm of ferromagnetic material located between the lower end of said cylindrical housing and said rim cap; and a surface sensor effectively attached to said flexible diaphragm and passing through the circular perforation of said rim cap.
Claim 15
Dependent Claim
47 words
A surface contour measuring apparatus according to claim 12, wherein said surface sensor comprises: an elongated rod effectively attached at one end to said flexible diaphragm; and a tip fastened to the end of said elongated rod that is opposite the end attached to said flexible diaphragm.
Claim 16
Dependent Claim
15 words
A surface contour measuring apparatus according to claim 13, wherein said tip comprises a wheel.
Claim 17
Dependent Claim
22 words
A surface contour measuring apparatus according to claim 11, wherein the predetermined frequency of said sinusoidal reference signal is four hundred hertz.
Claim 18
Dependent Claim
19 words
A surface contour measuring apparatus according to claim 11, wherein said servo drive motor comprises a two-phase induction motor.
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) | 1983-10-14 | 1984-04-14 | 1984-10-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-10-14 | 1988-04-14 | 1988-10-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-10-14 | 1992-04-14 | 1992-10-14 | $7700.00 | Window Closed / Lapsed |