US3871217A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Continuous cable tension monitor
Assignee: Rucker Co
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Filing: 1973-04-25
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Granted: 1975-03-18
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Expires: 1993-04-25
Abstract
Abstract A cable tension monitor has an electromagnet having a C-shaped pole piece extending along a cable adjacent thereto with the poles in a plane parallel to the cable axis. A coil on the pole piece is energized substantially at the natural frequency of the cable when under tension. A pair of pick-up coils are connected oppositely in series and are disposed on either side of the electromagnet close to the cable. The pick-up coils furnish repeated signals in accordance with perturbations in the magnetic field set up by the electromagnet and induced by cable vibration. The signals are used to time the energization of the electromagnet and to operate an indicating device. Spurious signals are rejected and noise is conditioned to the natural frequency of the cable. The indication given takes into account the stiffness of the cable.
Inventors
- 👤 David C Miley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 01:05
CPC Classifications
G; G01; G01L; G01L5/00; G01L5/04; G01L5/042; Y; Y10; Y10S; Y10S73/00; Y10S73/01
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
114 words
A cable tension monitor comprising an electromagnet having a pole adapted to be disposed adjacent a cable and having a magnet coil, a first electrical circuit including said magnet coil, means for periodically energizing said first circuit to establish a magnetic field adjacent said cable, a pair of pick-up devices disposed in said field spaced from opposite ends of said pole and effective to furnish repeated signals in accordance with perturbations in said field, an indicating device, means including a second electrical circuit and responsive to said repeated signals from said pick-up devices for controlling the frequency of energizing said first circuit, and means in said second electrical circuit for actuating said indicating device.
Claim 2
Dependent Claim
114 words
A cable tension monitor comprising an electromagnet having a pole adapted to be disposed adjacent a cable and having a magnet coil, a first electrical circuit including said magnet coil, means for periodically energizing said first circuit to establish a magnetic field adjacent said cable, a pair of pick-up devices disposed in said field spaced from opposite ends of said pole and effective to furnish repeated signals in accordance with perturbations in said field, an indicating device, means including a second electrical circuit and responsive to said repeated signals from said pick-up devices for controlling the frequency of energizing said first circuit, and means in said second electrical circuit for actuating said indicating device.
Claim 3
Dependent Claim
31 words
A device as in claim 1 including means in said second circuit for limiting said frequency to a frequency approximately the same as the natural frequency of said cable under tension.
Claim 4
Dependent Claim
42 words
A device as in claim 1 in which said means for energizing said first circuit employs an initially relatively high voltage to induce current in said magnet coil and a subsequent relatively low voltage to maintain said current in said magnet coil.
Claim 5
Dependent Claim
18 words
A device as in claim 1 in which said pick-up devices of said pair are connected in series.
Claim 6
Dependent Claim
23 words
A device as in claim 4 in which said pick-up devices include coils disposed on opposite ends of and adjacent to said electromagnet.
Claim 7
Dependent Claim
69 words
A device as in claim 1 in which said electromagnet has a C-shaped pole piece with the ends thereof terminating in substantially co-planar surfaces parallel to said cable, with the portion of said pole piece between said ends also parallel to said cable and with said magnet coil disposed on said portion between said ends with the axis of said coil substantially parallel with the axis of said cable.
Claim 8
Dependent Claim
19 words
A device as in claim 1 including manually controlled means in said first electrical circuit for introducing oscillations therein.
Claim 9
Dependent Claim
17 words
A device as in claim 1 including means for interrupting said means for actuating said indicating device.
Claim 10
Dependent Claim
33 words
A device as in claim 1 in which said actuating mass includes means for subtracting from said second electrical circuit a predetermined amount of energy corresponding to a factor correcting for cable stiffness.
Claim 11
Dependent Claim
13 words
A device as in claim 9 in which said predetermined amount is variable.
Claim 12
Dependent Claim
35 words
A device as in claim 1 including means in said second electrical circuit for conditioning random noise signals received by said pick-up devices into signals having substantially the natural frequency of said cable under tension.
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) | 1978-03-17 | 1978-09-16 | 1979-03-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-17 | 1982-09-16 | 1983-03-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-17 | 1986-09-16 | 1987-03-18 | $7700.00 | Window Closed / Lapsed |