MULTIFIBER SUBUNIT CABLE

• US 20120243841A1
• Filed: 06/07/2012
• Published: 09/27/2012
• Est. Priority Date: 12/14/2009
• Status: Active Grant

• Current Assignee: Corning Optical Communications LLC (Corning Incorporated)
• Original Assignee: Corning Optical Communications LLC (Corning Incorporated)
• Inventors: Hurley, William C., Navé, Samuel D.
• Granted Patent: US 8,718,428 B2
• Time in Patent Office: Days
• US Class Current: 385/113
• CPC Class Codes: B29C 48/15 incorporating preformed parts or layers, e.g. extrusion moulding around inserts
• CPC Class Codes: G02B 6/4401 Optical cables glass fibres with a protective coating G02B6/02395
• CPC Class Codes: G02B 6/4411 Matrix structure
• CPC Class Codes: G02B 6/443 Protective covering
• CPC Class Codes: G02B 6/4434 Central member to take up tensile loads

Abstract

Micromodule subunit cables are constructed to allow for ease of identification between optical fibers in differing groups of optical fibers. In one cable, a first group of fibers is located within a first subunit while a second group of fibers is located within a second subunit, both subunits being enclosed in a cable jacket.

Claims

1. A subunit cable, comprising:

a subunit cable jacket; and

at least two subunits located within the cable jacket, each subunit comprising;

a buffer tube; and

a plurality of optical fibers disposed within the buffer tube;

wherein

the subunits are compressed in the subunit cable jacket so that at least one of the subunits has a cross-section with a minor outside dimension and a major dimension, and the ratio of the minor outside dimension to the major outside dimension is less than 0.9.

2. The cable of claim 1, wherein the ratio of minor outside dimension to major outside dimension is less than 0.8.

3. The cable of claim 1, wherein the ratio of minor outside dimension to major outside dimension is less than 0.7.

4. The cable of claim 1, further comprising a strain-relief component disposed within the cable jacket, the strain-relief component comprising a plurality of longitudinally extending tensile yarns.

5. The cable of claim 4, wherein portions of the tensile yarns contact the subunits and the subunit cable jacket.

6. The cable of claim 1, wherein the cable jacket comprises a PVC and the buffer tubes comprise a PVC.

7. The cable of claim 1, wherein the at least two subunits comprises a first subunit and a second subunit, and wherein for each optical fiber in the first subunit, there is a corresponding optical fiber in the second subunit of identical color and appearance.

8. The cable of claim 7, wherein the first subunit comprises twelve optical fibers and the second subunit comprises twelve optical fibers.

9. The cable of claim 1, wherein a nominal outside diameter of the cable is less than 3.5 mm.

10. The cable of claim 1, wherein a nominal outside diameter of the cable is less than 3.3 mm.

11. The cable of claim 1, wherein the compressed subunits have a generally oval cross section.

12. A micromodule cable comprising a polymeric outer jacket;

a strength element; and

a plurality of cables according to claim 1 located within the outer jacket.

13. A method of making a subunit cable, comprising:

providing at least two subunits along a process direction, each subunit comprising a buffer tube and a plurality of optical fibers disposed within the buffer tube;

compressing the subunits so that at least one of the subunits has a cross-section with a minor outside dimension and a major outside dimension, and the ratio of the minor dimension to the major dimension is less than 0.9; and

extruding a subunit cable jacket around the subunits, wherein the subunits are compressed within the subunit cable jacket.

14. The method of claim 13, wherein the ratio of minor outside dimension to major outside dimension is less than 0.8.

15. The method of claim 13, further comprising paying off a tensile yarn strain-relief component, wherein the cable jacket is extruded around the strain-relief component, and wherein the tensile yarns contact the subunits and the subunit cable jacket.

16. The method of claim 13, wherein the at least two subunits comprises a first subunit and a second subunit, wherein for each optical fiber in the first subunit, there is a corresponding optical fiber in the second subunit of identical color and appearance.

17. The method of claim 16, wherein the first subunit comprises twelve optical fibers and the second subunit comprises twelve optical fibers, and wherein a nominal outside diameter of the cable is less than 3.5 mm.

18. The method of claim 16, wherein the first subunit comprises twelve optical fibers and the second subunit comprises twelve optical fibers, and wherein a nominal outside diameter of the cable is less than 3.3 mm.

19. The method of claim 13, wherein the cable jacket comprises a PVC and the buffer tubes comprise a PVC.

20. The method of claim 13, wherein the compressed subunits have a generally oval cross section.