STRENGTH MEMBER SYSTEM FOR FIBER OPTIC CABLE

• US 20130202262A1
• Filed: 03/20/2012
• Published: 08/08/2013
• Est. Priority Date: 02/03/2012
• Status: Active Grant

• Current Assignee: Corning Optical Communications LLC (Corning Incorporated)
• Original Assignee: Corning Optical Communications LLC (Corning Incorporated)
• Inventors: Haymore, Daniel P.
• Granted Patent: US 9,256,043 B2
• Time in Patent Office: Days
• US Class Current: 385/111
• CPC Class Codes: G02B 6/4413 Helical structure
• CPC Class Codes: G02B 6/4429 Means specially adapted for strengthening or protecting the cables
• CPC Class Codes: G02B 6/443 Protective covering
• CPC Class Codes: G02B 6/4434 Central member to take up tensile loads
• CPC Class Codes: G02B 6/44384 the means comprising water blocking or hydrophobic materials G02B6/4439, G02B6/4479 take precedence

Abstract

A fiber optic cable includes a strength member, a layer of polyethylene contacting the exterior of the strength member, and a yarn wound around the strength member. The yarn is between the strength member and the layer of polyethylene.

Claims

1. A fiber optic cable, comprising:

a strength member;

a layer of polyethylene contacting the exterior of the strength member; and

a yarn wound around the strength member, between the strength member and the layer of polyethylene.

2. The fiber optic cable of claim 1, wherein strength member is a glass-reinforced plastic rod having a longitudinal axis extending in parallel or co-linearly with a longitudinal axis of the fiber optic cable.

3. The fiber optic cable of claim 2, wherein the yarn is helically wound around the strength member.

4. The fiber optic cable of claim 3, wherein the yarn is water-swellable yarn.

5. The fiber optic cable of claim 4, wherein the water-swellable yarn comprises a super-absorbing polymer.

6. The fiber optic cable of claim 4, wherein the strength member is a central strength member coaxially located within the fiber optic cable.

7. The fiber optic cable of claim 6, further comprising:

buffer tubes supporting optical fibers; and

wherein the layer of polyethylene is an overcoat such that together the central strength member and the overcoat form a guide over which the buffer tubes are stranded.

8. The fiber optic cable of claim 7, wherein the yarn between the strength member and the layer of polyethylene consists of a single piece of yarn that is helically wound.

9. A method of manufacturing a fiber optic cable, comprising steps of:

winding a yarn around a strength member;

coating the strength member with a layer of polyethylene contacting the exterior of the strength member, wherein the yarn is between the strength member and the layer of polyethylene.

10. The method of claim 9, wherein the step of winding further comprises helically winding the yarn around the strength member.

11. The method of claim 10, wherein strength member is a glass-reinforced plastic rod having a longitudinal axis extending in parallel or co-linearly with a longitudinal axis of the fiber optic cable.

12. The method of claim 11, wherein the yarn is water-swellable yarn.

13. The method of claim 12, wherein the water-swellable yarn comprises a super-absorbing polymer.

14. The method of claim 12, wherein the strength member is a central strength member coaxially located within the fiber optic cable.

15. The method of claim 14, wherein the layer of polyethylene is an overcoat, and the method further comprising a step of stranding buffer tubes, which are supporting optical fibers, around a guide formed by the overcoat, the yarn, and the central strength member.

16. The method of claim 15, wherein the yarn between the strength member and the layer of polyethylene consists of a single piece of yarn that is helically wound.

17. The method of claim 9, wherein the step of winding further comprises counter-helically winding separate pieces of the yarn around the strength member such that the pieces form a crisscross pattern with respect to one another around the strength member.

18. A fiber optic cable, comprising:

a guide, comprising;

a strength member comprising a glass-reinforced plastic rod having a longitudinal axis extending in parallel or co-linearly with a longitudinal axis of the fiber optic cable,

a first water-swellable yarn helically wound around the rod; and

a polymer overcoat overlaying the first yarn and the rod;

a second water-swellable yarn helically wound around the exterior of the guide;

buffer tubes stranded around the guide and overlaying the second yarn, wherein the buffer tubes support optical fibers; and

a polymer jacket overlaying the buffer tubes.

19. The fiber optic cable of claim 18, wherein the polymer of the jacket and the polymer of the overcoat are the same material.

20. The fiber optic cable of claim 19, wherein the polymer of the jacket and the overcoat is polyethylene.