US5109456A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Optical fiber unit
Assignee: Sumitomo Electric Industries Ltd
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Filing: 1991-03-07
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Granted: 1992-04-28
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Expires: 2011-03-07
Abstract
Abstract An optical fiber unit including a plurality of sub-units. Each sub-units includes a plurality of optical fibers. Further, the sub-units are twisted together, with a twist pitch in the range of from 30 to 600 mm. Each group of optical fibers are coated with a primary layer to form a sub-unit. The sub-units are then twisted together and coated by a secondary coating. A porous layer is applied onto the secondary layer, thus forming the optical fiber unit.
Inventors
- 👤 Hiroaki Sano
- 👤 Yoshiaki Terasawa
- 👤 Shigeru Tanaka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 09:13
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/46; G02B6/50; G02B6/52; G02B6/44; G02B6/4401; G02B6/4429; G02B6/4438
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
79 words
An optical fiber unit for laying and pushing forward into a previously laid duct line by means of a flow of fluid pressure-sent into said duct line, said optical fiber unit comprising: a plurality of sub-units each of which is formed of a plurality of optical fibers gathered and coated with a primary coating, wherein said plurality of sub-units is twisted; a secondary coating applied over said plurality of sub-units; and a porous coating coated on said secondary coating.
Claim 2
Dependent Claim
79 words
An optical fiber unit for laying and pushing forward into a previously laid duct line by means of a flow of fluid pressure-sent into said duct line, said optical fiber unit comprising: a plurality of sub-units each of which is formed of a plurality of optical fibers gathered and coated with a primary coating, wherein said plurality of sub-units is twisted; a secondary coating applied over said plurality of sub-units; and a porous coating coated on said secondary coating.
Claim 3
Dependent Claim
20 words
An optical fiber unit as claimed in claim 1, wherein each of said plurality of sub-units includes seven optical fibers.
Claim 4
Dependent Claim
20 words
An optical fiber unit as claimed in claim 1, wherein each of said plurality of sub-units includes four optical fibers.
Claim 5
Dependent Claim
20 words
An optical fiber unit as claimed in claim 1, wherein each of said plurality of sub-units includes three optical fibers.
Claim 6
Dependent Claim
26 words
An optical fiber unit as claimed in claim 1, wherein said plurality of sub-units have a twist pitch in the range from 30 to 600 mm.
Claim 7
Dependent Claim
28 words
An optical fiber unit as claimed in claim 5, wherein the twist pitch of said plurality of sub-units is in the range of from 200 to 500 mm.
Claim 8
Independent Claim
55 words
A method of forming an optical fiber unit, said method comprising the steps of: encasing a plurality of optical fibers in a primary coating, and thus forming a sub-unit; twisting a plurality of sub-units together; forming a secondary coating layer around said twisted plurality of sub-units; and coating a porous layer over said secondary coating.
Claim 9
Independent Claim
55 words
A method of forming an optical fiber unit, said method comprising the steps of: encasing a plurality of optical fibers in a primary coating, and thus forming a sub-unit; twisting a plurality of sub-units together; forming a secondary coating layer around said twisted plurality of sub-units; and coating a porous layer over said secondary coating.
Claim 10
Dependent Claim
29 words
A method as in claim 7, wherein said twisting step includes imparting a twist pitch in the range of from 30 to 600 mm to said plurality of sub-units.
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) | 1995-04-28 | 1995-10-28 | 1996-04-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-04-28 | 1999-10-28 | 2000-04-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-04-28 | 2003-10-28 | 2004-04-28 | $7700.00 | Window Closed / Lapsed |