High density riser and plenum breakout cables for indoor and outdoor cable applications

• US 5,857,051 A
• Filed: 04/21/1997
• Issued: 01/05/1999
• Est. Priority Date: 04/21/1997
• Status: Expired due to Fees

• Current Assignee: Fitel USA Corporation (Furukawa Electric Company Limited)
• Original Assignee: Lucent Technologies, Inc. (Nokia Corporation)
• Inventors: Viriyayuthakorn, Montri, Travieso, Ruben
• Primary Examiner(s): Palmer, Phan T. H.
• Application Number:
  US08/844,745
• Time in Patent Office: 624 Days
• Field of Search: 385/100-114
• US Class Current: 385/114
• CPC Class Codes: G02B 6/4403 with ribbon structure G02B6/4429, G02B6/4439, G02B6/4479 take precedence
• CPC Class Codes: G02B 6/4411 Matrix structure
• CPC Class Codes: G02B 6/443 Protective covering

Abstract

The breakout cable is made up of an arrangement of optical fiber ribbon structures. Arranged above and/or below the optical fibers in each of the ribbon structures are strength members which are preferably made of an aramid fiber, such as KEVLAR. The combined optical fibers and strength members are surrounded by a sheath, which is preferably made of a suitable plastic, such as a material selected from the group consisting of polyolefin, PVC, low smoke PVC, EVA, FEP, PVDF, and thermoplastic fluoropolymers, thereby forming the high strength, sheathed optical fiber ribbon structure arrangement. A plurality of these individually sheathed ribbon structures can be stacked to form higher density ribbon bundles, or subunits, which can be further surrounded by sheaths. Similarly, a large numbers of such high density ribbon bundle subunits can be combined within a protective sheath to form cables which can be pulled through risers and plenums in the construction of premises, such as apartment buildings or commercial buildings, or used in appropriate indoor/outdoor applications. Accordingly, even as subunits are broken out of the cables, and as ribbon structures are broken out of the subunits, the optical fibers will still be surrounded by high strength members which will help protect them from breakage.

Claims

1. An optical fiber ribbon bundle comprising:

(a) a plurality of ribbon structures, each of said ribbon structures comprising;

(i) a plurality of optical fibers, each of said optical fibers being adjacent to another optical fiber, wherein each said ribbon structure has a single layer of optical fibers and each said ribbon structure has a top side above said layer of optical fibers and a bottom side below said layer of optical fibers, when said layer of optical fibers is viewed on edge through a cross-section thereof;

(ii) at least one strength member being positioned along one of said top side or said bottom side, said at least one strength member being made of a fiber material having a breaking strength which is substantially greater than that of said optical fibers; and

(iii) a protective sheath which surrounds said optical fibers and said strength member;

(b) a subunit sheath which surrounds all of said ribbon structures within said ribbon bundle; and

(c) said ribbon structures filling a portion of space inside of said subunit sheath with a remainder of said space being filled by air.

2. The optical fiber ribbon bundle of claim 1 wherein said protective sheath which surrounds each individual ribbon structure is made of a material selected from the group consisting of polyolefin, PVC, low smoke PVC, EVA, FEP, PVDF, and thermoplastic fluoropolymers.

3. The optical fiber ribbon bundle of claim 2 wherein said subunit sheath which surrounds all of the individual ribbons structures within said ribbon bundle is made of a material selected from the group consisting of polyolefin, PVC, low smoke PVC, EVA, FEP, PVDF, and thermoplastic fluoropolymers.

4. The high density fiber optic cable of claim 1 wherein said ribbon bundles are helically wound.

5. The high density fiber optic cable of claim 1 wherein said ribbon bundles are bound together in a reverse oscillating lay.

6. A high density fiber optic cable for premises wiring comprising a plurality of fiber optic ribbon bundles, each ribbon bundle comprising:

(a) a plurality of ribbons made of optical fibers, each of said ribbons comprising;

(i) a plurality of optical fibers, each of said optical fibers being adjacent to another optical fiber, whereby said ribbon has a single layer of optical fibers and said ribbon has a top side above said layer and a bottom side below said layer, when said layer is viewed on edge through a cross-section thereof;

(ii) at least one strength member being arranged along one of said top side or said bottom side, said strength member being made of a fiber material having a breaking strength which is substantially greater than that of said optical fibers; and

(iii) a protective sheath which surrounds said ribbon and said strength member; and

(b) a subunit sheath which surrounds all of said ribbons within said ribbon bundle;

(c) said ribbons filling a portion of space inside of said subunit sheath with a remainder of said space being filled by air; and

(d) an outer sheath which surrounds a plurality of said ribbon bundles.

7. The high density fiber optic cable of claim 6 wherein said ribbon bundles are helically wound.

8. The high density fiber optic cable of claim 7 wherein said ribbon bundles are powdered in order to allow them to slip relative to one another.

9. The high density fiber optic cable of claim 8 wherein said ribbon bundles are powdered with talc.

10. The high density fiber optic cable of claim 9 wherein said protective sheath which surrounds each individual ribbon structure is made of a material selected from the group consisting of polyolefin, PVC, low smoke PVC, EVA, FEP, PVDF, and thermoplastic fluoropolymers.

11. The high density fiber optic cable of claim 10 wherein said subunit sheath which surrounds all of the individual ribbons structures within said ribbon bundle is made of a material selected from the group consisting of polyolefin, PVC, low smoke PVC, EVA, FEP, PVDF, and thermoplastic fluoropolymers.

12. The high density fiber optic cable of claim 6 wherein said ribbon bundles are bound together in a reverse oscillating lay.

13. The high density fiber optic cable of claim 12 wherein said ribbon bundles are powdered in order to allow them to slip relative to one another.

14. The high density fiber optic cable of claim 13 wherein said ribbon bundles are powdered with talc.