US3726129A
Expired / Lapsed
US
⏱️ 0.0 years remaining
System for measuring the resonant frequency of a body
Assignee: United Kingdom Atomic Energy Authority
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Filing: 1970-11-16
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Granted: 1973-04-10
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Expires: 1990-11-16
Abstract
Abstract Various physical characteristics of a solid body are dependent upon its natural frequency of vibration and the invention describes a method whereby a body may be excited to resonance through the operation of a remote transducer, and once resonance is achieved it may be preserved, even though the value thereof alters. By measuring the variations in resonance, environment conditions, such as temperature, may be deduced.
Inventors
- 👤 E Thorne
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 03:40
CPC Classifications
G; G01; G01K; G01K11/00; G01K11/22; G01K11/26; G01H; G01H13/00; G01V; G01V7/00; G01V7/005
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
221 words
Apparatus for the monitoring of the resonant frequency of a body comprising an electric oscillator, a control device for controlling the frequency of said oscillator in response to an input signal, a transducer connected to said oscillator for delivering an output in the form of bursts of elastic waves whose frequency within the burst corresponds to that of the oscillator, a transmission line connected at one end thereof to the transducer output including a terminal portion at the other end thereof remote from the transducer, a body having a discrete resonant frequency associated with the terminal portion of said transmission line such that echos of bursts of elastic waves launched at said resonant frequency into said one end of the transmission line and transmitted back from said body contain a discontinuity and echos received from bursts of elastic waves at a non-resonant frequency are continuous within the burst, means for converting the echos of the bursts of elastic waves into electrical pulses, means for generating a continuous pulse train, means for comparing said electrical pulses with said continuous pulse train and for delivering an output pulse when a discontinuity in the burst of echo pulses occurs, and means for employing a pulse so delivered as an input signal to said control device to maintain the oscillator frequency at said resonant frequency.
Claim 2
Dependent Claim
221 words
Apparatus for the monitoring of the resonant frequency of a body comprising an electric oscillator, a control device for controlling the frequency of said oscillator in response to an input signal, a transducer connected to said oscillator for delivering an output in the form of bursts of elastic waves whose frequency within the burst corresponds to that of the oscillator, a transmission line connected at one end thereof to the transducer output including a terminal portion at the other end thereof remote from the transducer, a body having a discrete resonant frequency associated with the terminal portion of said transmission line such that echos of bursts of elastic waves launched at said resonant frequency into said one end of the transmission line and transmitted back from said body contain a discontinuity and echos received from bursts of elastic waves at a non-resonant frequency are continuous within the burst, means for converting the echos of the bursts of elastic waves into electrical pulses, means for generating a continuous pulse train, means for comparing said electrical pulses with said continuous pulse train and for delivering an output pulse when a discontinuity in the burst of echo pulses occurs, and means for employing a pulse so delivered as an input signal to said control device to maintain the oscillator frequency at said resonant frequency.
Claim 3
Dependent Claim
64 words
Apparatus as claimed in claim 1 including a free-running multivibrator whose pulse output is suppressed by the electrical pulse train obtained from echos at nonresonant frequency, means for extracting a pulse or pulses from the multivibrator output when a discontinuity in the electrical pulse train occurs at resonance and means for employing the extracted pulse or pulses to control the frequency of the oscillator.
Claim 4
Dependent Claim
29 words
Apparatus as claimed in claim 1 in which the oscillator sweeps through a frequency band and means are provided for interrupting the frequency sweep when an extracted pulse appears.
Claim 5
Dependent Claim
101 words
Apparatus as claimed in claim 1 comprising a solid resonator, an acoustic transmission line for leading bursts of acoustic pulses to the resonator, a transducer for converting electrical pulses into acoustic waves and launching these waves into the transmission line, a voltage controlled oscillator for supplying the transducer, the oscillator having a frequency range which includes the natural frequency of vibration of the resonator, means for connecting the oscillator to a voltage source and means for interrupting the connection between oscillator and the voltage source in response to an echo signal from the resonator which is indicative of the resonant frequency.
Claim 6
Dependent Claim
54 words
Apparatus as claimed in claim 4 in which said connecting means comprises relay contacts included in the connection between the oscillator and the voltage source and means allowing the relay contacts to open in response to a signal derived from an echo at resonance in order to stop the oscillator at the resonant frequency.
Claim 7
Dependent Claim
23 words
Apparatus as claimed in claim 5 including means for reading out the frequency of the oscillator at which the voltage source is interrupted.
Claim 8
Dependent Claim
33 words
Apparatus as claimed in claim 6 including a means for reading out the value of the oscillator at the point at which the connection between the voltage source and the oscillator is interrupted.
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) | 1976-04-09 | 1976-10-09 | 1977-04-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-09 | 1980-10-09 | 1981-04-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-09 | 1984-10-09 | 1985-04-10 | $7700.00 | Window Closed / Lapsed |