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Patent US4565099A successfully refreshed from Google Patents.
US4565099A
Expired / Lapsed
US
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Method and apparatus for determining tension in a cable
Assignee: Gulf Energy Co
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Filing: 1984-09-04
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Granted: 1986-01-21
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Expires: 2004-09-04
Abstract
Abstract A method and apparatus for measuring tension in a suspended cable or the like, wherein the tension may be derived from sensor signals corresponding to the fundamental frequency of vibration in the cable and which enables accurate tension measurements to be made from sensors located at or near the terminal end of a span of cable.
Inventors
- 👤 William S. Arnold
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 12:42
CPC Classifications
G; G01; G01L; G01L5/00; G01L5/04; G01L5/042
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
100 words
An apparatus for measuring tension in a cable or like object comprising: sensor means for sensing vibrations occurring in the object, said sensor means further including means for generating a sensor signal indicative of the sensed frequency of vibration in the object under observation; filter means for receiving the sensor signal and providing as an output a compensated sensor signal, said filter means having a characteristic frequency response which is substantially the inverse function of the characteristic frequency response of said sensor means; tension deriving means for receiving the compensated sensor signal and deriving therefrom a signal analogous to tension.
Claim 2
Independent Claim
100 words
An apparatus for measuring tension in a cable or like object comprising: sensor means for sensing vibrations occurring in the object, said sensor means further including means for generating a sensor signal indicative of the sensed frequency of vibration in the object under observation; filter means for receiving the sensor signal and providing as an output a compensated sensor signal, said filter means having a characteristic frequency response which is substantially the inverse function of the characteristic frequency response of said sensor means; tension deriving means for receiving the compensated sensor signal and deriving therefrom a signal analogous to tension.
Claim 3
Dependent Claim
61 words
The apparatus of claim 1, wherein said tension deriving means comprises an electrical circuit adapted to solve the equations T=(2FL) 2 M where T is the tension in the object; F is the sensed fundamental frequency of vibration; L is the span length of the object under observation; and M is the mass per unit length of the object under observation.
Claim 4
Dependent Claim
180 words
The apparatus of claim 2 wherein said tension deriving means comprises: frequency to voltage converter circuit means for receiving the compensated sensor signal as an input signal and providing an output signal analogous to the frequency of the compensated sensor signal; a first multiplier circuit means for receiving the output signal from said converter circuit means as an input signal and providing an output signal which is analogous to the product of the input signal received from said converter circuit multiplied by the span length of the object under observation; squaring circuit means for receiving the output signal from said first multiplier circuit means as an input signal and providing an output signal which is analogous to the square of the signal received from said first multiplier circuit means; and a second multiplier circuit means for receiving the output signal from said squaring means as an input signal and providing an output signal which is analogous to the product of the signal received from said squaring circuit means multiplied by the weight per unit length of the object under observation.
Claim 5
Dependent Claim
69 words
The apparatus of claim 3 wherein: said first multiplier circuit means includes an amplifier circuit means an adjustable gain to permit adjustment of the multiplier value corresponding to the length of the object under observation; and said second multiplier circuit means includes an amplifier circuit means having an adjustable gain to permit adjustment of the multiplier value corresponding to the weight per unit length of the object under observation.
Claim 6
Dependent Claim
64 words
The apparatus of claim 1, wherein: said sensor means comprises means for generating a signal which is indicative of sensed velocity of vibrations in the object under observation; and said filter means includes a low pass filter circuit having a frequency response characterized by a negative six decibel per octave slope on a logarithmic scale in the frequency bandwidth of the tension measuring apparatus.
Claim 7
Dependent Claim
35 words
The apparatus of claim 5 wherein said filter means further comprises: a high pass filter circuit having a frequency response characterized by a threshold frequency corresponding to the desired low frequency response of the apparatus.
Claim 8
Dependent Claim
62 words
The apparatus of claim 1, wherein: said sensor means comprises means for generating a signal indicative of sensed acceleration of vibrations in the object under observation; and said filter means includes a low pass filter circuit having a frequency response characterized by a negative twelve decibels per octave slope on a logarithmic scale in the frequency bandwidth of the tension measuring apparatus.
Claim 9
Dependent Claim
35 words
The apparatus of claim 7 wherein said filter means further comprises: a high pass filter circuit having a frequency response characterized by a threshold frequency corresponding to the desired low frequency response of the apparatus.
Claim 10
Dependent Claim
55 words
The apparatus of claim 1, wherein: said sensor means comprises means for generating a signal indicative of the displacement of vibrations in the object under observation; and said filter means comprises a high pass filter circuit having a frequency response characterized by a threshold frequency corresponding to the desired low frequency response of the apparatus.
Claim 11
Dependent Claim
136 words
The apparatus of claim 1 wherein said sensor means may be selected to be means for generating a signal indicative of either the displacement or velocity of vibrations in the object under observation; and wherein said filter means further comprises: a lead in high pass filter circuit having a frequency response characterized by positive six decibel per octave slope on a logarithmic scale in the frequency bandwidth of the tension measuring apparatus for initially processing signals from said displacement probe only; a high pass filter circuit having a frequency response with a threshold frequency corresponding to the desired low frequency response of the apparatus; and a low pass filter circuit having a frequency response characterized by a negative six decibel per octave slope on a logarithmic scale in the frequency bandwidth of the tension measuring apparatus.
Claim 12
Independent Claim
67 words
A method for measuring tension in a cable or like object comprising the steps of: sensing vibrations occurring in the object; generating a sensor signal indicative of the sensed vibrations; normalizing the sensor signal to the lowest frequency component of the sensor signal within the bandwidth of the apparatus; deriving a tension value corresponding to the tension in the object under observation from the normalized sensor signal.
Claim 13
Independent Claim
67 words
A method for measuring tension in a cable or like object comprising the steps of: sensing vibrations occurring in the object; generating a sensor signal indicative of the sensed vibrations; normalizing the sensor signal to the lowest frequency component of the sensor signal within the bandwidth of the apparatus; deriving a tension value corresponding to the tension in the object under observation from the normalized sensor signal.
Claim 14
Dependent Claim
54 words
The method of claim 11, wherein said step of normalizing the sensor signal comprises: providing the sensor signal to a filter circuit having a characteristic frequency response which is substantially the inverse function of the frequency response of the means used to carry out the steps of sensing vibrations and generating the sensor signal.
Claim 15
Dependent Claim
62 words
The method of claim 11, wherein said step of deriving a tension value comprises deriving a solution to the equation T=(2FL) 2 M where T is the tension in the object; F is the sensed fundamental frequency of vibration; L is the span length of the object under observation; and M is the mass per unit length of the object under observation.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-01-20 | 1989-07-22 | 1990-01-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-01-20 | 1993-07-22 | 1994-01-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-01-20 | 1997-07-22 | 1998-01-21 | $7700.00 | Window Closed / Lapsed |