US4596443A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Light guide for liquid detection and cable comprising such a guide
Assignee: Nederlanden Posterijen Telegrafie en Telefonie Staatsbedrif der
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Filing: 1985-04-18
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Granted: 1986-06-24
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Expires: 2005-04-18
Abstract
Abstract A glass-fibre cable has been provided with a signalling conductor for signalling liquid which has penetrated into the cable sheath. The signalling conductor is a glass fibre, which is inserted in a protective perforated sheath in the usual way. The inner periphery of this sheath is provided with a wave-shaped pattern on one side, whereas the opposite side is provided with a layer of swelling powder. As soon as the liquid which has entered the cable, reaches the swelling powder, the volume of this swelling powder will considerably increase, in consequence of which the glass fibre will be pressed against the wave-shaped pattern. This causes microbending which involves a strong, measurable attenuation of the light signal transmitted through the glass fibre. The swelling powder can be applied to a substrate.
Inventors
- 👤 Martinus B. J. Diemeer
- 👤 Alphonsus G. W. M de Jongh
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 15:19
CPC Classifications
G; G01; G01N; G01N19/00; G01N19/10; G01M; G01M3/00; G01M3/02; G01M3/04; G01M3/042; G01M3/045; G01M3/047; G02; G02B; G02B6/00; G02B6/44; G02B6/4401; G02B6/4415; G02B6/4439; G02B6/4469
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
82 words
A moisture signalling conductor comprising: (A) an elongated tubular element pervious to moisture and having a rib-shaped pattern pressure area therein, (B) a light guide in said tubular element, and (C) a swellable material in said tubular element which swellable material swells under the influence of moisture entering into said tubular element to deform and press said light guide against said pressure area to produce detectable attenuation in said light guide for indicating the location of said moisture in said tubular element.
Claim 2
Dependent Claim
82 words
A moisture signalling conductor comprising: (A) an elongated tubular element pervious to moisture and having a rib-shaped pattern pressure area therein, (B) a light guide in said tubular element, and (C) a swellable material in said tubular element which swellable material swells under the influence of moisture entering into said tubular element to deform and press said light guide against said pressure area to produce detectable attenuation in said light guide for indicating the location of said moisture in said tubular element.
Claim 3
Dependent Claim
31 words
A moisture signalling conductor according to claim 1 wherein said pressure area is provided with a wave-shaped pattern causing periodic microbending in said light guide when pressed against said pressure area.
Claim 4
Dependent Claim
23 words
A moisture signalling conductor according to claim 1 wherein said swellable material inserted in said tubular element has been applied to a substrate.
Claim 5
Dependent Claim
18 words
A moisture signalling conductor according to claim 3 wherein said substrate has a cross-section which is substantially round.
Claim 6
Dependent Claim
30 words
A moisture signalling conductor according to claim 1 wherein said tubular element comprises a membrane which is mounted as a separating wall between said swellable material and said light guide.
Claim 7
Dependent Claim
92 words
In a cable having a sheath pervious to moisture and a star-shaped cross-sectional core forming longitudinal notches, at least one of said notches containing: (A) a swellable material which swells under the influence of moisture, (B) a light guide, and (C) a rib-shaped pattern pressure area against which said light guide is pressed and deformed by the swelling of said swellable material to produce a detectable attenuation in a signal transmitted in said light guide for indicating the location of the moisture in said cable which caused said swellable material to swell.
Claim 8
Dependent Claim
92 words
In a cable having a sheath pervious to moisture and a star-shaped cross-sectional core forming longitudinal notches, at least one of said notches containing: (A) a swellable material which swells under the influence of moisture, (B) a light guide, and (C) a rib-shaped pattern pressure area against which said light guide is pressed and deformed by the swelling of said swellable material to produce a detectable attenuation in a signal transmitted in said light guide for indicating the location of the moisture in said cable which caused said swellable material to swell.
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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) | 1989-06-23 | 1989-12-23 | 1990-06-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-06-23 | 1993-12-23 | 1994-06-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-06-23 | 1997-12-23 | 1998-06-24 | $7700.00 | Window Closed / Lapsed |