US3715659A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Inductive non-contact vibration analyzer which is independent of standoff distance
Assignee: Reliance Electric Co
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Filing: 1970-03-25
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Granted: 1973-02-06
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Expires: 1990-03-25
Abstract
Abstract Disclosed is a non-contact vibration analyzer that is substantially independent of standoff distance. An inductive probe produces an electrical output having AC and DC components that vary similarly with standoff. An automatic gain control circuit maintains the DC component constant so that the AC output signal is representative of vibration and does not vary with standoff. By connecting the probe through a meter zero potentiometer and switch to a DC meter, the analyzer also indicates shaft runout.
Inventors
- 👤 A Abnett
- 👤 G Foster
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 08:54
CPC Classifications
G; G01; G01M; G01M7/00
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
161 words
A vibration analyzer comprising a high frequency oscillator, an inductive probe coupled to said oscillator, said probe producing an electrical output indicative of the proximity of said probe to a metal surface, said output including both AC and DC components bearing an exponential relationship to standoff distance,with said DC component including a constant DC level, means including a difference amplifier coupled to the output of said probe for removing said constant DC level from said probe output, an automatic gain control circuit coupled to the output of said amplifier and including a voltage divider with a variable resistor, a tunable filter coupled to the output of said gain control circuit, a DC meter, a detector coupled to the output of said filter, a switch having a first position for coupling said detector to said meter, and a meter zero potentiometer coupled to the output of said difference amplifier, said switch having a second position for coupling said potentiometer to said meter.
Claim 2
Dependent Claim
161 words
A vibration analyzer comprising a high frequency oscillator, an inductive probe coupled to said oscillator, said probe producing an electrical output indicative of the proximity of said probe to a metal surface, said output including both AC and DC components bearing an exponential relationship to standoff distance,with said DC component including a constant DC level, means including a difference amplifier coupled to the output of said probe for removing said constant DC level from said probe output, an automatic gain control circuit coupled to the output of said amplifier and including a voltage divider with a variable resistor, a tunable filter coupled to the output of said gain control circuit, a DC meter, a detector coupled to the output of said filter, a switch having a first position for coupling said detector to said meter, and a meter zero potentiometer coupled to the output of said difference amplifier, said switch having a second position for coupling said potentiometer to said meter.
Claim 3
Dependent Claim
161 words
A vibration analyzer comprising a high frequency oscillator, an inductive probe coupled to said oscillator, said probe producing an electrical output indicative of the proximity of said probe to a metal surface, said output including both AC and DC components bearing an exponential relationship to standoff distance,with said DC component including a constant DC level, means including a difference amplifier coupled to the output of said probe for removing said constant DC level from said probe output, an automatic gain control circuit coupled to the output of said amplifier and including a voltage divider with a variable resistor, a tunable filter coupled to the output of said gain control circuit, a DC meter, a detector coupled to the output of said filter, a switch having a first position for coupling said detector to said meter, and a meter zero potentiometer coupled to the output of said difference amplifier, said switch having a second position for coupling said potentiometer to said meter.
Claim 4
Dependent Claim
161 words
A vibration analyzer comprising a high frequency oscillator, an inductive probe coupled to said oscillator, said probe producing an electrical output indicative of the proximity of said probe to a metal surface, said output including both AC and DC components bearing an exponential relationship to standoff distance,with said DC component including a constant DC level, means including a difference amplifier coupled to the output of said probe for removing said constant DC level from said probe output, an automatic gain control circuit coupled to the output of said amplifier and including a voltage divider with a variable resistor, a tunable filter coupled to the output of said gain control circuit, a DC meter, a detector coupled to the output of said filter, a switch having a first position for coupling said detector to said meter, and a meter zero potentiometer coupled to the output of said difference amplifier, said switch having a second position for coupling said potentiometer to said meter.
Claim 5
Dependent Claim
20 words
Apparatus according to claim 1 including a second detector connected between the output of said probe anD said difference amplifier.
Claim 6
Dependent Claim
18 words
Apparatus according to claim 2 including a low pass filter coupling said second detector to said difference amplifier.
Claim 7
Dependent Claim
30 words
Apparatus according to claim 1 wherein said AC and DC components of said probe output both vary as exponentials of the standoff distance of said probe from said metal surface.
Claim 8
Dependent Claim
20 words
Apparatus according to claim 1 including an AC output terminal connected between said gain control circuit and said tunable filter.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-02-06 | 1976-08-07 | 1977-02-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-02-06 | 1980-08-07 | 1981-02-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-02-06 | 1984-08-07 | 1985-02-06 | $7700.00 | Window Closed / Lapsed |