Pre-connectorized fiber optic distribution cable having multifiber connector

• US 20050111800A1
• Filed: 10/13/2004
• Published: 05/26/2005
• Est. Priority Date: 11/26/2003
• Status: Active Grant

• Current Assignee: Corning Optical Communications LLC (Corning Incorporated)
• Original Assignee: Corning Cable Systems LLC (Corning Incorporated)
• Inventors: Luther, James P., Cooke, Terry L., Knecht, Dennis M., Elkins, Robert B. II, Johnson, John B., Nielsen, Lars K.
• Granted Patent: US 7,088,893 B2
• Time in Patent Office: Days
• US Class Current: 385/100
• CPC Class Codes: G02B 6/4431 with provision in the protective covering, e.g. weak line, for gaining access to one or more fibres, e.g. for branching or tapping break-out terminations G02B6/4471
• CPC Class Codes: G02B 6/4473 Three-way systems
• CPC Class Codes: G02B 6/4475 with provision for lateral branching G02B6/4431 takes precedence

Abstract

A factory-prepared preterminated and pre-connectorized fiber optic distribution cable having at least one mid-span access location for providing access to a plurality of preterminated optical fibers pre-connectorized with a multi-fiber connector is provided. Also provided is a method of forming a pre-connectorized fiber optic distribution cable by terminating and pre-connectorizing a predetermined number of the plurality of optical fibers of the cable to create a pre-connectorized mid-span access location. The fiber optic distribution cable provides a low profile mid-span access location that is sufficiently flexible to be installed through relatively small-diameter buried conduits and over aerial installation sheave wheels and pulleys without violating the minimum bend radius of the cable or the optical fibers. A protective encapsulant protects and seals the mid-span access location during cable reeling, unreeling, installation and until the access location is needed for interconnecting a connectorized fiber optic drop or branch cable.

Claims

1. A pre-connectorized fiber optic distribution cable comprising:

a plurality of optical fibers disposed within the cable;

at least one predetermined access location along the length of the cable, the access location configured prior to installation of the cable in a fiber optic communications network, the access location providing access to the plurality of optical fibers such that two or more of the optical fibers are preterminated from the remaining optical fibers in the cable; and

a multi-fiber connector mounted upon the ends of the terminated optical fibers.

2. A pre-connectorized fiber optic distribution cable having at least one predetermined mid-span access location for accessing a plurality of preterminated and pre-connectorized optical fibers, the cable comprising:

a plurality of optical fibers disposed within the cable;

a transition piece operable for transitioning preterminated ones of the plurality of optical fibers out of the cable;

a multi-fiber connector mounted upon the ends of the preterminated optical fibers;

an elongate member defining a longitudinally extending optical fiber guide channel operable for storing a predetermined useable length of the preterminated optical fibers and the multi-fiber connector; and

a protective means operable for protecting and sealing the at least one mid-span access location during installation of the pre-connectorized fiber optic distribution cable.

3. The pre-connectorized distribution cable of claim 2, wherein the protective means is a heat deformable material operable for securing the elongate member and for providing a smooth transition between an outer diameter of the cable and the elongate member.

4. The pre-connectorized distribution cable of claim 2, wherein the protective means is an over-molded encapsulating shell.

5. The pre-connectorized distribution cable of claim 2, wherein the distribution cable, the transition piece, the elongate member and the protective means are sufficiently flexible to permit installation through buried conduits and over aerial installation sheave wheels and pulleys.

6. The pre-connectorized distribution cable of claim 2, wherein a length of the preterminated and pre-connectorized optical fibers ranges from about 10 to about 30 inches.

7. The pre-connectorized distribution cable of claim 2, further comprising at least one ripcord disposed underneath the protective means operable for removing the protective means after cable installation.

8. The pre-connectorized distribution cable of claim 2, further comprising a closure affixed to the cable following installation and operable for encapsulating and sealing the at least one mid-span access location.

9. The pre-connectorized distribution cable of claim 2, wherein the transition piece and the elongate member are each C-shaped so as to permit the transition piece and the elongate member to be affixed to the cable without being threaded onto the cable.

10. The pre-connectorized distribution cable of claim 2, further comprising a water-swellable tape disposed between the protective means and the elongate member.

11. A pre-connectorized fiber optic distribution cable having at least one access location for providing access to a plurality of preterminated and pre-connectorized optical fibers, comprising:

a plurality of optical fibers disposed within at least one tube, at least a portion of the plurality of optical fibers being preterminated and withdrawn from the tube at the at least one access location;

a multi-fiber pigtail comprising a multi-fiber connector optically connected to the preterminated optical fibers;

a tube transition piece operable for transitioning the plurality of optical fibers out of the tube and the cable; and

a protective shell for encapsulating the access location, wherein the protective shell remains on the cable during installation and until the at least one access location is needed for interconnecting a branch cable or drop cable.

12. The pre-connectorized distribution cable of claim 11, wherein the protective shell is a heat deformable material.

13. The pre-connectorized distribution cable of claim 11, wherein the protective shell is an over-molded encapsulating shell.

14. The pre-connectorized distribution cable of claim 11, wherein the cable, the at least one tube, the tube transition piece and the protective shell are sufficiently flexible to permit installation through buried conduits and over aerial installation sheave wheels and pulleys.

15. The pre-connectorized distribution cable of claim 11, wherein a predetermined useable length of the preterminated and pre-connectorized optical fibers ranges from about 10 to about 30 inches.

16. The pre-connectorized distribution cable of claim 11, further comprising at least one ripcord disposed underneath the protective shell operable for removing the protective shell following installation of the cable.

17. A method of forming a preterminated and pre-connectorized fiber optic distribution cable in the factory prior to installing the cable in a fiber optic communications network to provide a pre-connectorized mid-span access location, comprising:

removing a predetermined length of a cable sheath to expose at least one buffer tube;

cutting at least two access points along the length of the buffer tube;

severing a plurality of optical fibers disposed within the buffer tube at a first downstream access point to produce a predetermined number of preterminated optical fibers;

fishing the preterminated optical fibers out of an upstream access point to withdraw a useable length of the preterminated optical fibers;

transitioning the useable length f the preterminated optical fibers out of the buffer tube and the cable via a buffer tube transition piece; and

pre-connectorizing the preterminated optical fibers with a multi-fiber connector.

18. The method of claim 17, further comprising positioning and maintaining the preterminated and pre-connectorized optical fibers in an elongate member comprising a longitudinally extending optical fiber guide channel;

and

protecting and sealing the mid-span access location with a protective encapsulant.

19. The method of claim 18, wherein the protective encapsulant is a heat deformable material.

20. The method of claim 18, wherein the protective encapsulant is an over-molded shell.