Dry core optical fiber cables for premises applications and methods of manufacture

• US 6,205,277 B1
• Filed: 02/19/1999
• Issued: 03/20/2001
• Est. Priority Date: 02/19/1999
• Status: Expired due to Fees

• Current Assignee: Fitel USA Corporation (Furukawa Electric Company Limited)
• Original Assignee: Lucent Technologies, Inc. (Nokia Corporation)
• Inventors: Shmukler, Mark I., Viriyayuthakorn, Montri, Mathis, Terry D., Wilson, Carla G., Newton, Wayne M., Sheu, Jim J.
• Primary Examiner(s): Bovernick, Rodney
• Assistant Examiner(s): PAK, SUNG H
• Application Number:
  US09/253,412
• Time in Patent Office: 760 Days
• Field of Search: 385/102, 385/103, 385/104, 385/105, 385/106
• US Class Current: 385/106
• CPC Class Codes: G02B 6/441 built up from sub-bundles G02B6/4429, G02B6/4439, G02B6/4479 take precedence
• CPC Class Codes: G02B 6/44384 the means comprising water blocking or hydrophobic materials G02B6/4439, G02B6/4479 take precedence
• CPC Class Codes: G02B 6/449 Twisting

Abstract

A preferred embodiment of the dry core optical fiber cable of the present invention incorporates a plurality of sub-units with each of said sub-units being arranged adjacent another of the sub-units so that the plurality of sub-units define an outer periphery. Preferably, each of the sub-units includes a plurality of optical fibers, a yarn layer and a sub-unit jacket, with each of the optical fibers being arranged adjacent another of the optical fibers. The sub-unit jacket surrounds the optical fibers, with the yarn layer being disposed between the optical fibers and the sub-unit jacket. An outer jacket surrounds the plurality of sub-units, with water-blocking tape being disposed between the outer jacket and the outer periphery of the sub-units. A method of manufacture of the cable also is provided.

Claims

1. A dry core optical cable comprising:

a plurality of sub-units, each of said sub-units arranged adjacent another of said sub-units such that said plurality of sub-units define an outer periphery, each of said sub-units comprising;

a plurality of optical fibers, a yarn layer and a sub-unit jacket, each of said optical fibers arranged adjacent another of said optical fibers, said sub-unit jacket surrounding said optical fibers, said yarn layer disposed between said optical fibers and said sub-unit jacket;

a second yarn member surrounded by said plurality of sub-units;

an elongated organizer disposed within said second yarn member;

an outer jacket surrounding said plurality of sub-units; and

water-blocking tape disposed between said outer jacket and said outer periphery of said plurality of sub-units.

2. The cable of claim 1, wherein said yarn layer comprises water-blocking aramid yarn.

3. The cable of claim 1, wherein said plurality of optical fibers surround a first yarn member.

4. The cable of claim 1, wherein each of said optical fibers is a buffered optical fiber.

5. The cable of claim 1, wherein said plurality of sub-units comprises at least four of said sub-units.

6. The cable of claim 3, wherein said first yarn member comprises a water-blocking aramid yarn.

7. The cable of claim 1, wherein said organizer has a glass rod and an outer layer of plastic formed about said glass rod.

8. The cable of claim 6, wherein said second yarn member comprises water-blocking yarn.

9. The cable of claim 8, wherein said second yarn member is helically wound about said organizer.

10. A dry core optical cable comprising:

an elongated organizer having a first breaking strength;

at least one water-blocking yarn member arranged about said organizer;

a plurality of sub-units arranged in reverse-oscillated lay about said organizer such that said water-blocking yarn member is disposed between said organizer and said plurality of sub-units, each of said sub-units arranged adjacent another of said sub-units, each of said sub-units comprising;

a plurality of optical fibers, a water-blocking aramid yarn layer and a sub-unit jacket, each of said optical fibers having a second breaking strength and being arranged adjacent another of said optical fibers, said sub-unit jacket surrounding said optical fibers, said water-blocking aramid yarn layer disposed between said optical fibers and said sub-unit jacket, said first breaking strength being greater than said second breaking strength;

an outer jacket surrounding said plurality of sub-units; and

water-blocking tape surrounding and in contact with said outer periphery of said plurality of sub-units and disposed between said outer jacket and said outer periphery of said plurality of sub-units.

11. The cable of claim 10, wherein said plurality of optical fibers surround a water-blocking aramid yarn member.

12. The cable of claim 10, wherein each of said optical fibers is a buffered optical fiber.

13. The cable of claim 10, wherein said plurality of sub-units comprises at least four of said sub-units.

14. A method of manufacturing dry core optical fiber cable comprising the steps of:

providing at least one water-blocking yarn;

providing an elongated organizer;

wrapping said water-blocking yarn about said organizer;

wrapping a plurality of sub-units about said water-blocking yarn in a reverse-oscillated lay, each of said sub-units comprising;

a plurality of optical fibers, a yarn layer and a sub-unit jacket, each of said optical fibers arranged adjacent another of said optical fibers, said sub-unit jacket surrounding said optical fibers, said yarn layer disposed between said optical fibers and said sub-unit jacket;

wrapping said plurality of sub-units with water-blocking tape; and

forming an outer jacket about said plurality of sub-units and said water-blocking tape such that said water-blocking tape is disposed between said plurality of sub-units and said outer jacket.

15. The method of claim 14, wherein the step of providing said elongated organizer comprises providing said elongated organizer having a glass rod and an outer layer of plastic formed about said glass rod;

and wherein the step of wrapping said water-blocking yarn comprises wrapping said water-blocking yarn about said outer layer of said organizer.

16. The method of claim 14, wherein the step of forming an outer jacket comprises extruding a plastic outer jacket about said plurality of sub-units and said water-blocking tape.