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US4812014A
Expired / Lapsed
US
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Water penetration-detecting apparatus and optical fiber cable using same
Assignee: Fujikura Ltd
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Filing: 1987-05-06
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Granted: 1989-03-14
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Expires: 2007-05-06
Abstract
Abstract A water penetration-detecting apparatus includes an optical fiber sensor having an optical fiber, and a water-absorbent material disposed along the optical fiber in contiguous relation to the fiber. The water-absorbent material, when absorbing water, expands volumetrically so as to apply a pressure to an outer peripheral surface of the optical fiber to bend the fiber. A detecting means is connected to the optical fiber sensor for detecting a bending of the optical fiber.
Inventors
- 👤 Hiroyuki Sawano
- 👤 Hideo Suzuki
- 👤 Yasuyuki Sugawara
- 👤 Kazunaga Kobayashi
- 👤 Nobuyasu Sato
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 13:55
CPC Classifications
G; G01; G01M; G01M3/00; G01M3/02; G01M3/04; G01M3/16; G01M3/165; G01M3/042; G01M3/045; G01M3/047
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
71 words
A water penetration-detecting apparatus comprising: (a) an optical fiber sensor comprising (i) an optical fiber, and (ii) a water-absorbent material disposed along said optical fiber in contiguous relation to said fiber, said water-absorbent material, when absorbing water, expanding volumetrically so as to apply a pressure to an outer peripheral surface of said optical fiber to bend said fiber; and (b) a detecting means for detecting a bending of said optical fiber.
Claim 2
Dependent Claim
71 words
A water penetration-detecting apparatus comprising: (a) an optical fiber sensor comprising (i) an optical fiber, and (ii) a water-absorbent material disposed along said optical fiber in contiguous relation to said fiber, said water-absorbent material, when absorbing water, expanding volumetrically so as to apply a pressure to an outer peripheral surface of said optical fiber to bend said fiber; and (b) a detecting means for detecting a bending of said optical fiber.
Claim 3
Dependent Claim
28 words
An apparatus according to claim 1, in which said water-absorbent material is in the form of a coating mounted around an entire circumferential surface of said optical fiber.
Claim 4
Dependent Claim
30 words
An apparatus according to claim 2, in which an elongated expansion-restraint member is spirally wound around said water-absorbent coating so as to limit a radial expansion of said water-absorbent coating.
Claim 5
Dependent Claim
43 words
An apparatus according to claim 2, in which a plurality of expansion-restraint elements of a ring-like shape are mounted around said water-absorbent coating and spaced from one another along said optical fiber, said expansion-restraint elements limiting a radial expansion of said water-absorbent coating.
Claim 6
Dependent Claim
98 words
An apparatus according to claim 3, in which an expansion-restraint member in the form of a tubular net is fitted over said water-absorbent coating so as to limit a radial expansion of said water-absorbent coating. An optical fiber cable comprising (a) a sheath; (b) a plurality of communication optical fibers mounted within said sheath; (c) an optical fiber sensor mounted within said sheath and comprising (i) an optical fiber, and (ii) a water-absorbent material disposed along said optical fiber of said sensor in contiguous relation thereto, said water-absorbent material, when absorbing water, expanding volumetrically so as to apply
Claim 7
Dependent Claim
49 words
An apparatus according to claim 1, in which the optical fiber comprises an expansion restraint member disposed in the vicinity of and extending along said water-absorbent material so as to direct expansion of the water-absorbent material towards the optical fiber to thereby bend the optical fiber when absorbing water.
Claim 8
Dependent Claim
30 words
An apparatus according to claim 6, in which said expansion-restraint member is of an annular cross-section and has water-passage means for passing water radially therethrough to the water absorbent material.
Claim 9
Dependent Claim
25 words
An apparatus according to claim 7, in which said water-absorbent material is in the form of a rod disposed generally parallel to said optical fiber.
Claim 10
Dependent Claim
17 words
An apparatus according to claim 7, in which said water-absorbent material is in the form of yarns.
Claim 11
Dependent Claim
30 words
An apparatus according to claim 7, in which said water-absorbent material is in the form of powder filled in a space formed between said optical fiber and said expansion-restraint member.
Claim 12
Dependent Claim
57 words
An apparatus according to claim 7, in which said water-absorbent material is in the form of a coating mounted around an entire circumferential surface of said optical fiber, said water-passage means being provided along a straight line, said optical fiber being disposed eccentric with respect to said water-absorbent coating in a direction away from said water-passage means.
Claim 13
Dependent Claim
26 words
An apparatus according to claim 1, in which said water-absorbent material is in the form of a rod around which said optical fiber is spirally wound.
Claim 14
Dependent Claim
76 words
An apparatus according to claim 12, in which an elongated expansion-restraint member is spirally wound around said optical fiber in such a manner that said optical fiber and said expansion-restraint member intersect each other at points spaced along the length of said rod-like water-absorbent member and that said expansion-restraint member overlies said optical fibers at the intersections between said expansion-restraint member and said optical fiber, said expansion-restraint member limiting a radial expansion of said water-absorbent rod.
Claim 15
Dependent Claim
105 words
An optical fiber cable comprising: (a) a sheath; (b) a plurality of communication optical fibers mounted within said sheath; (c) an optical fiber sensor mounted within said sheath and comprising (i) an optical fiber, and (ii) a water-absorbent material disposed along said optical fiber of said sensor in contiguous relation thereto, said water-absorbent material, when absorbing water, expanding volumetrically so as to apply a pressure to an outer peripheral surface of said optical fiber of said sensor to bend said fiber, said optical fiber sensor being adapted to be connected to a detecting means for detecting a bending of said optical fiber of said sensor.
Claim 16
Dependent Claim
105 words
An optical fiber cable comprising: (a) a sheath; (b) a plurality of communication optical fibers mounted within said sheath; (c) an optical fiber sensor mounted within said sheath and comprising (i) an optical fiber, and (ii) a water-absorbent material disposed along said optical fiber of said sensor in contiguous relation thereto, said water-absorbent material, when absorbing water, expanding volumetrically so as to apply a pressure to an outer peripheral surface of said optical fiber of said sensor to bend said fiber, said optical fiber sensor being adapted to be connected to a detecting means for detecting a bending of said optical fiber of said sensor.
Claim 17
Dependent Claim
87 words
An optical fiber cable according to claim 14, in which there is provided a spacer of a tubular shape having an central axial bore therethrough and covered by said sheath, a plurality of spiral grooves being formed on an outer peripheral surface of said spacer, a tension wire of a high tensile strength being received in and extending along said axial bore, said optical fiber sensor being received in one of said spiral grooves while said communication optical fibers are received in the other spiral grooves, respectively.
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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) | 1992-03-13 | 1992-09-12 | 1993-03-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-03-13 | 1996-09-12 | 1997-03-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-03-13 | 2000-09-12 | 2001-03-14 | $7700.00 | Window Closed / Lapsed |