WO2013103858A1

WO2013103858A1 - Multi-fiber patchcord and process for the manufacture thereof

Info

Publication number: WO2013103858A1
Application number: PCT/US2013/020335
Authority: WO
Inventors: Wayne M. Kachmar; William F. WRIGHT; Wagner Da Silva Aguiar
Original assignee: Adc Telecommunications, Inc.
Priority date: 2012-01-06
Filing date: 2013-01-04
Publication date: 2013-07-11

Abstract

A fiber optic cable includes a furcation tube defining an axial passage; and optical fibers having intermediate sections extending through the axial passage of the furcation tube. Ribbonized sections of the optical fibers are disposed at the first and second ends of the furcation tube, respectively. Manufacturing the fiber optic cable includes ribbonizing optical fibers to form a first ribbonized section from which a non-ribbonized section extends; attaching a first end of a pull cord to the first ribbonized section; and pulling the first ribbonized section through the axial passage of the furcation tube using the pull cord. Alternatively, manufacturing the fiber optic cable may include curving a portion of a plurality of optical fibers along a first length; ribbonizing the portion of the plurality of optical fibers along the first length after curving the portion of the plurality of optical fibers along the first length to form a first ribbonized section of optical fibers from which a non-ribbonized section extends, wherein the first ribbonized section is curve shaped; and moving the first ribbonized section through an axial passage of the furcation tube, wherein the curve shape of the first ribbonized section assists moving the first ribbonized section through the axial passage of the furcation tube.

Description

T/US2013/020335

MULTI-FIBER PATCHCORD AND PROCESS FOR THE MANUFACTURE

THEREOF

This application is being filed on 04 January 2013, as a PCT International Patent application and claims priority to U.S. Patent Application Serial No.

61/583,837 filed on 06 January 2012, the disclosure of which is incorporated herein by reference in its entirety.

Technical Field

The present disclosure relates to the manufacture of multi-fiber patch cords.

Background

It may be expensive to maintain large inventories of connectorized fibers having different fiber counts, fiber types, and jacket specifications. Ribbonized fiber cables have preferred bending axes. Bundled loose fibers can require

significant assembly time to separate and organize into ribbonized ends to prepare the fibers for insertion into connector ferrules.

Summary

Some aspects of the disclosure are directed to an optical fiber cable including multiple optical fibers extending through a furcation tube. The optical fibers are loosely bundled along at least a majority of the length of the furcation tube. The optical fibers are ribbonized at both ends to facilitate insertion into connector ferrules. In further aspects of the disclosure the ribbonized sections are curved or non-planar to assist insertion into the furcation tube.

Other aspects of the disclosure are directed to a manufacturing process by which optical fiber cables are produced. The manufacturing process includes ribbonizing optical fibers along a first length to form a first ribbonized section of optical fibers from which a non-ribbonized section extends; attaching a first end of a pull cord to the first ribbonized section; and pulling the first ribbonized section through an axial passage of a furcation tube using the pull cord.

Additional aspects of the disclosure are directed to a manufacturing process by which optical fiber cables are produced. The manufacturing process includes curving a portion of a plurality of optical fibers along a first length; ribbonizing the portion of the plurality of optical fibers along the first length after curving the portion of the plurality of optical fibers along the first length to form a first ribbonized section of optical fibers from which a non-ribbonized section extends; and moving the first ribbonized section through an axial passage of a furcation tube. The first ribbonized section is curve shaped. The curve shape of the first ribbonized section assists moving the first ribbonized section through the axial passage of the furcation tube. Brief Description of the Drawings

FIG. 1 illustrates an embodiment of a schematic diagram of a multi-fiber optical cable having loosely bundled fibers extending through a furcation tube and ribbonized at both ends of the cable;

FIG. 2 illustrates an embodiment of an end perspective view of an example furcation tube and pull cord with the outer jacket of the furcation tube partially removed to reveal the strength layer of the furcation tube;

FIG. 3 illustrates an embodiment of a schematic diagram of optical fibers being ribbonized at a ribbonizing assembly;

FIG. 4 illustrates an embodiment of a schematic diagram of the ribbonized optical fibers being attached to a pull cord; and

FIG. 5 illustrates an embodiment of a schematic diagram of a furcation tube pulling assembly that threads the optical fibers through the furcation tube.

FIG. 6 illustrates a transverse cross-sectional view of an embodiment of a schematic diagram of a planar fiber optic ribbon and a furcation tube.

FIG. 7 illustrates a transverse cross-sectional view of an embodiment of a schematic diagram of a non-planar fiber optic ribbon and a furcation tube.

FIG. 8 illustrates a transverse cross-sectional view of an embodiment of a schematic diagram of a non-planar fiber optic ribbon and a furcation tube. Detailed Description

The present disclosure relates to a multi-fiber optical cable (e.g., a patch cord) that has no preferred bend axis and that has optical fibers grouped in ribbons at each end to facilitate insertion of the optical fibers into ferrules of optical connectors. The cable includes a furcation tube that accommodates bundles of optical fibers ribbonized at discrete locations at either end of the furcation tube to allow quick identification and alignment of large numbers of optical fibers into multi fiber ferrules. In some embodiments the discrete location of the ribbonized optical fibers are curved to assist insertion of the optical fibers into the furcation tube. The present disclosure also relates to the manufacture of such multi-fiber optical cables.

FIG. 1 is a schematic representation of an example multi-fiber optical cable 100. FIG. 1 is not drawn to scale. The multi-fiber optic cable 100 includes multiple optical fibers 120 extending through a furcation tube 1 10. The furcation tube 1 10 defines an axial passage 1 13 extending from a first end 1 1 1 of the furcation tube 1 10 to a second end 109 of the furcation tube 1 10. The optical fibers 120 have a third section 122, a first section 124, and a second section 126. The third section 122 of the optical fibers 120 extends through the axial passage 1 13 of the furcation tube 1 10. The first section 124 of the optical fibers 120 is disposed at the first end 1 1 1 of the furcation tube 1 10 and the second section 126 of the optical fibers 120 is disposed at the second end 109 of the furcation tube 1 10.

The optical fibers 120 are loose (e.g., loosely bundled) at the third section 122 and are ribbonized at the first and second sections 124, 126. The third section 122 of the optical fibers 120 is significantly longer than the first and second sections 124, 126 of the optical fibers 120. For example, in some implementations, the third section 122 is at least twice as long as the first and second sections 124, 126. In certain implementations, the third section 122 is at least three times as long as the first and second sections 124, 126. In certain implementations, the third section 122 is at least five times as long as the first and second sections 124, 126. In certain implementations, the third section 122 is at least ten times as long as the first and second sections 124, 126.

Ribbonizing the ends (e.g., sections 124, 126) of the optical fibers 120 facilitates identification of the individual fibers 120 and termination of the fibers 120 at a fiber optic connector (e.g., a multi-fiber connector such as an MPO/MTP connector). Additionally, in some implementations, the optical fibers 120 are color coded for facilitating identification of individual fibers 120. Accordingly, ribbonizing the ends (e.g., sections 124, 126) of the optical fibers 120 provides the establishment of a fiber identification order (e.g., via color identification) and reliable spatial positioning of the fibers 120. Leaving the fibers 120 loose (e.g., loosely bundled) along the length of the furcation tube 1 10 provides a cable 100 that does not have a preferred bend axis.

In some implementations, the optical cable 100 includes at least six optical fibers 120. In certain implementations, the optical cable 100 includes at least twelve optical fibers 120. In certain implementations, the optical cable 100 includes at least forty-eight optical fibers 120. In certain implementations, the optical cable 100 includes about 144 optical fibers 120. In other implementations, the cable 100 may include a greater or lesser number of fibers 120. In some implementations, the cable 100 has a length of no more than about 100 meters. In certain implementations, the cable 100 has a length of no more than about 50 meters. In certain implementations, the cable 100 has a length of no more than about 25 meters. In one example implementations, the cable 100 has a length of about 10 meters.

FIG. 2 illustrates one example furcation tube 1 10 suitable for use in the optical cable 100 of FIG. I . The example furcation tube 1 10 is a dual reinforced furcation tube 1 10 configured to accommodate tensile and elongation requirements of patch cord cable and/or meet specific safety and protection requirements. The furcation tube 1 10 includes a buffer tube 1 12, a strength layer 1 14, and a jacket 1 16. The buffer tube 1 12 defines the axial passage 1 13. In some implementations, the strength layer 1 14 incorporates a contrahelical set of yarns (e.g., aramid or fiberglass or other) that will provide the tensile strength, shrink and expansion characteristics as well as the specific protection requirements (temperature range, fire retardance, vibration, chemical resistance etc.). In some implementations, furcation tubes 110 of various dimensions may be manufactured and stored in inventors to accommodate various fiber counts and performance types (plenum, Low Smoke Zero Halogen (LSZH) aerospace, etc.).

As shown in FIG. 2, in some embodiments, the furcation tube 1 10 also includes a pulling member 130 (e.g., a pull cord) extending through the axial passage 1 13. In some implementations, the pull member 130 includes an aramid yarn that is formed disposed within the furcation tube 1 10 during a forming and extrusion process. The pulling member 130 enables the optical fibers 120 to be inserted into the furcation tube 1 10 subsequent to the formation of the tube 1 10. In multi-fiber cables 100, the optical fibers 120 are the largest cost component.

Accordingly, a cable 100 configured so that the fibers 120 need not be incorporated into the cable 100 until the specific demand for cable fiber type, count, and total quantity are known is advantageous. The inventory cost for the cable 100 may be reduced since only the total number of fibers 120 in a cable 100 need to be in inventory as single reels 1 80 (FIG. 5) of fiber 120.

FIGS. 3-5 illustrate the manufacturing process for the example multi-fiber optical cable 100. As shown in FIG. 3, the manufacturing process includes ribbonizing a portion of a number of optical fibers 120 along a first length to form a first ribbonized section 124 from which a non-ribbonized section 122 extends. For example, in some implementations, the individual optical fibers 120 may be spooled off tension-controlled payoffs (e.g., reels) 180 and fed into a ribbonizing arrangement 150. In the example shown, the ribbonizing arrangement 150 includes a fiber organizing guide 152, a ribbonizing die 154, and a ribbon cutting block 156.

In some implementations, the ribbonizing process is performed using a UV curable ribbonizing solution. In other implementations, the ribbonizing process is performed using ribbonizing tape. In additional implementations, the ribbonizing process is performed using ribbonizing adhesive, such as glue. The ribbonizing material may be flexible or non-flexible when hardened or cured. In some implementations, the first ribbonized section 124 is no more than twenty centimeters (cm) in length. In certain implementations, the first ribbonized section 124 is no more than fifteen cm in length. In certain implementations, the first ribbonized section 124 is about ten cm in length. In certain implementations, the first ribbonized section 124 is about five cm in length.

In some implementations, the ribbonized section 124 and/or 126 is planar or substantially planar as illustrated in FIG. 6. In alternative implementations, the ribbonized section 124 and/or 126 is non-planar or curved (i.e., curved in the short dimension of the ribbon or across the width of the ribbon) as illustrated in FIGS. 7 and 8. In some embodiments, to form a ribbonized section 124 and/or 126 that is curved, the plurality of optical fibers 120 along a first length are inserted into a P T/US2013/020335 curved shaped mold before ribbonizing the plurality of optical fibers 120 along that first length. Once the plurality of optical fibers 120 along that first length have been ribbonized (e.g. the UV curable solution, adhesive, or tape has cured or hardened), the curved shaped mold is removed from the ribbonized section 124 and/or 126.

Accordingly, the individual fibers cooperate to define a curve in the ribbonized section 124 and/or 126 when viewed in a transverse cross-sectional view as illustrated in FIGS. 7 and 8. Therefore, the optical fibers 120 are not curved but instead cooperate to define a curve in the ribbonized section 124 and/or 126.

Typically, ribbonized sections 124, 126 were utilized for splicing or connectorizing processes. Accordingly, the ribbonized sections 124, 126 needed to be planar. However, the ribbonized sections 124, 126 as utilized herein facilitate insertion into the furcation tube 1 10. Accordingly, a ribbonized section 124 and/or 126 that is planar, as illustrated in FIG. 6, will have to bend to move through the furcation tube 1 10 because the internal diameter of the axial passage 1 13 (e.g., illustrated as 2.1 mm in FIGS. 6-8) of the furcation tube 1 10 is smaller than the width of the ribbon. A ribbonized section 124 and/or 126 that is curved shaped exhibits less resistance to deformation when moved through a small diameter hole or into a tube, compared to a flat ribbon. When a flat or non-planar ribbonized section 124 and/or 126 is forced into a restricted space, such as when it is forced through hole or a tube with a diameter smaller than the width of the ribbon, the non-planar ribbonized section 124 and/or 126 is more likely to incur damage (fiber to fiber separation and/or fiber coating damage), compared to a ribbonized section 124 and/or 126 that was originally fabricated in a non-planar or curved orientation because the curved shaped ribbonized section 124 and/or 126 will be distorted less than the flat ribbon to move through the same hole or diameter.

For example, as illustrated in FIGS. 7, the curved ribbonized section 124 and/or 126 with a radius of the curve shape that is larger than the inner diameter of the axial passage 1 13 of the furcation tube 1 10 will be distorted less than the flat ribbonized section 124 and/or 126 to fit within the axial passage 1 13 of the furcation tube 1 10. Further, the curved ribbonized section 124 and/or 126 with a radius of the curve shape that is smaller than the inner diameter of the axial passage 1 13 of the furcation tube 1 10 will not have to be distorted to fit within the axial passage 1 13 in contrast to the flat or planar ribbonized section 124 and/or 126. Accordingly, a curved or non-planar ribbonized section 124 and/or 126 assists insertion into furcation tube 1 10.

Therefore, the curved or non-planar ribbonized section 124 and/or 126 may be pushed and/or pulled into the furcation tube 1 10. In some implementations, the curved or non-planar ribbonized section 124 and/or 126 further includes a pull cord to facilitate insertion into furcation tube 1 10, which is discussed in more detail below. In some embodiments, the ribbonizing material, such as tape, adhesive, and/or UV curable solution that is flexible after curing or hardening, is utilized to further assist insertion into furcation tube 1 10.

Utilizing a ribbonized section 124 and/or 126 that is curved shaped reduces the amount of physical deformation on the ribbonized section 124 and/or 126 when moving through the furcation tube 1 10 when compared to a flat or planar ribbonized section. Accordingly, as discussed above, a curved ribbonized section 124 and/or 126 reduces damage to and/or fiber to fiber separation of the ribbonized section when moving through the furcation tube 1 10 when compared to a ribbonized section that is planar or flat.

As shown in FIG. 4, the manufacturing process also includes attaching a first end 132 of the pull cord 130 to the first ribbonized section 124. In some

implementations, the attachment of the pull cord 130 to the first ribbonized section 124 is implemented at the ribbon cutting block 156. In certain implementations, the first end 132 of the pull cord 130 is attached to the first ribbonized section 124 using adhesive (e.g., UV curable solution or glue). In other implementations, the first end 132 of the pull cord 130 is attached to the first ribbonized section 124 using tape.

In some implementations, the optical fibers 120 are grouped into a single ribbonized section 124. In other implementations, the optical fibers 120 may be grouped into multiple ribbonized sections 124. In some implementations, each of the ribbonized sections 124 may be attached to a separate pull member 130. In other implementations, two or more of the ribbonized sections 124 may be attached to the same pull member 130. In further implementations, one or more of the multiple ribbonized sections 124 may be curved shaped. As shown in FIG. 5, the manufacturing process also includes pulling the one or more first ribbonized sections 124 of the optical fibers 120 through the axial passage 1 13 of the furcation tube 1 10 using the one or more pull cords 130. For example, in some implementations, the furcation tube 1 10 is laid out straight on a pulling bench 160. A first end of the bench 160 is located towards the ribbonizing arrangement 150 and the reels 180. A machine 170 for applying a pulling force to the pull cord 130 is located at the second end of the bench 160. For example, the machine 170 may include a torque drive catapuller. In the example shown, the machine 170 includes a stepper controlled pulling motor and pinch rollers 175 through which the pull member 130 is fed. The fibers 120 are pulled through the furcation tube 1 10 by the catapuller under controlled tension and torque to a predetermined length. In an alternative implementation, the pull member 130 is manually pulled to pull the fibers 120 through the furcation tube 1 10.

When the ribbonized section 124 has been moved through the furcation tube 1 10 by a predetermined amount, the optical fibers 120 are ribbonized along a second length to form one or more second ribbonized sections 126. For example, the second ribbonized section(s) 126 may be formed when the first ribbonized section(s) 124 has been pulled along a majority of the length of the furcation tube 1 10.

In some embodiments, once a ribbonized section 124 and/or 126 that is curved shaped has been pull through the furcation tube by a predetermined amount, the curved ribbonized sections 124 and/or 126 are removed, such as by being cut off. In further embodiments, once the ribbonized sections 124 and/or 126 that are curved are removed, the optical fibers 120 may be ribbonized to form ribbonized sections 124 and/or 126 that are planar or flat.

When the second section(s) 126 has been ribbonized, the first and second ribbonized sections 124, 126 are disposed at the opposite ends (109, 1 1 1 ) of the furcation tube 1 10. In some implementations, the ribbonized sections 124, 126 are disposed wholely within the furcation tube 1 10. In other implementations, the ribbonized sections 124, 126 are disposed partly within the furcation tube 1 10. In other implementations, the ribbonized sections 124, 126 are disposed outside of and adjacent to the furcation tube 1 10. The non-ribbonized section(s) 122 of the optical fibers 120 extends along the axial passage 1 13 of the furcation tube 1 10. In some implementations, each of the one or more second ribbonized sections 126 is cut into two parts. The first part forms a second ribbonized section 126 for the optical fiber cable 100. The second part forms a first ribbonized section 124 for the next cable 100 to be manufactured. For example, the ribbonized section 126 may be cut in half. When the next cable 100 is to be manufactured, the first manufacturing step is already complete, thereby saving time and increasing efficiency.

Claims

Claims:

1. A fiber optic cable comprising:

a furcation tube defining an axial passage extending from a first end of the furcation tube to a second end of the furcation tube, the furcation tube including an inner buffer tube, a strength layer, and an outer jacket; and

a plurality of optical fibers having a first section, a second section, and a third section, the first section of the optical fibers extending through the axial passage of the furcation tube, the second section of the optical fibers being disposed at the first end of the furcation tube, and the third section of the optical fibers being disposed at the second end of the furcation tube, the second and third sections of the optical fibers being ribbonized.

2. The fiber optic cable of claim 1 , wherein the strength layer includes contra- helically served strength members.

3. The fiber optic cable of claim 2, wherein the strength members are formed from aramid yarn.

4. The fiber optic cable of claim 2, wherein the strength members are formed from fiberglass.

5. The fiber optic cable of claim 1 , wherein the second and third sections of the optical fibers are each no more than about 10 cm in length.

6. The fiber optic cable of claim 5, wherein the second and third sections of the optical fibers are each about 5 cm in length.

7. The fiber optic cable of claim 1 , wherein the plurality of optical fibers includes at least six optical fibers.

8. The fiber optic cable of claim 1 , wherein the second sections of the optical fibers form multiple ribbons and the third sections of the optical fibers form multiple ribbons.

9. A method of manufacturing a fiber optic cable having a furcation tube defining an axial passage through which a pull cord extends, the method comprising: ribbonizing a portion of a plurality of optical fibers along a first length to form a first ribbonized section of optical fibers from which a non-ribbonized section extends;

attaching a first end of the pull cord to the first ribbonized section; and pulling the first ribbonized section through the axial passage of the furcation tube using the pull cord.

10. The method of claim 9, further comprising ribbonizing the optical fibers along a second length to form a second ribbonized section at a second end of the furcation tube.

The method of claim 10, further comprising slicing the second ribbonized

12. The method of claim 9, wherein pulling the first ribbonized section through the axial passage of the furcation tube comprises pulling the pull cord using a catapuller.

13. The method of claim 9, wherein attaching the first end of the pull cord to the first ribbonized section comprises attaching the first end of the pull cord using UV adhesive.

14. The method of claim 9, wherein providing the furcation tube comprises forming the furcation tube including forming a buffer tube that defines the axial passage and forming an outer jacket.

15. The method of claim 14, wherein forming the furcation tube comprises contra-helically serving strength members around the buffer tube and extruding the outer jacket over the strength members.

The method of claim 14, wherein forming the furcation tube comprises g the furcation tube with the pull cord.

17. The method of claim 9, further comprising attaching a fiber optic connector to the respective ribbonized section at each end of the furcation tube.

18. The method of claim 9, wherein ribbonizing the plurality of optical fibers comprises ribbonizing the plurality of optical fibers using a UV curable ribbonizing solution.

19. The method of claim 9, wherein ribbonizing the plurality of optical fibers comprises ribbonizing the plurality of optical fibers using ribbonizing tape.

20. The method of claim 9, further comprising curving the plurality of optical fibers along the first length before ribbonizing the portion of the plurality of optical fibers along the first length to form the first ribbonized section of optical fibers into a curve shape, wherein the curve shape assists pulling the first ribbonized section through the axial passage of the furcation tube.

21. The method of claim 20, wherein a radius of the curve shape is smaller than an inner diameter of the axial passage of the furcation tube.

22. The method of claim 20, wherein the curving the plurality of optical fibers along the first length before ribbonizing comprises inserting the plurality of optical fibers into a curved shaped mold.

23. The method of claim 9, further comprising: ribbonizing first portions of additional optical fibers along respective first lengths to form respective first ribbonized sections of optical fibers from which respective non-ribbonized sections extend;

attaching the first end of the pull cord to each of the first ribbonized sections of the additional optical fibers;

pulling the first ribbonized sections through the axial passage of the furcation tube from the first end towards a second end using the pull cord;

ribbonizing the additional optical fibers along second lengths to form second ribbonized sections at the second end of the furcation tube; and

continuing to pull the first ribbonized sections so that at least a majority of each non-ribbonized section of additional optical fibers is disposed within the axial passage.

24. A method for manufacturing a fiber optic cable having a furcation tube defining an axial passage, the method comprising:

curving a portion of a plurality of optical fibers along a first length;

ribbonizing the portion of the plurality of optical fibers along the first length after curving the portion of the plurality of optical fibers along the first length to form a first ribbonized section of optical fibers from which a non-ribbonized section extends, wherein the first ribbonized section is curve shaped; and

moving the first ribbonized section through an axial passage of the furcation tube, wherein the curve shape of the first ribbonized section assists moving the first ribbonized section through the axial passage of the furcation tube.

25. The method of claim 24, wherein a radius of the curve shape is smaller than an inner diameter of the axial passage of the furcation tube.

26. The method of claim 24, wherein curving the portion of the plurality of optical fibers along the first length comprises inserting the portion of the plurality of optical fibers along the first length into a curved shaped mold.

27. The method of claim 24, wherein moving the first ribbonized section through the axial passage of the furcation tube comprises pulling the first ribbonized section through the axial passage of the furcation tube.

28. The method of claim 24, wherein moving the first ribbonized section through the axial passage of the furcation tube comprises pushing the first ribbonized section through the axial passage of the furcation tube.

29. The method of claim 24, wherein curve shape of the first ribbonized section reduces physical deformation of the first ribbonized section while moving through the axial passage of the furcation tube when compared to planar ribbonized sections.

30. The method of claim 24, wherein curve shape of the first ribbonized section reduces damage to the first ribbonized section while moving through the axial passage of the furcation tube when compared to planar ribbonized sections.

3 1 . The method of claim 24, wherein curve shape of the first ribbonized section reduces fiber separation of the first ribbonized section while moving through the axial passage of the furcation tube when compared to planar ribbonized sections.