Hybrid ferrule boot for standard and small OD fibers

Abstract

A ferrule boot (100) to assist keeping adhesives from wicking in a multi-fiber ferrule (10) includes a body (102), a first opening (130) in the body (102) extending from the front end (112) toward the back end and a second opening (132) in the body extending longitudinally toward the front end (112), the first opening (130) and the second opening (132) in communication with each other. There is also a first internal seal (160) disposed at a junction (134) of the first opening (130) and the second opening (132), the first internal seal (160) extending around at least of portion of the second opening (132) and narrowing the second opening (132) at the junction (134) of the first opening (130) and the second opening (132). There may also be a third opening (140) with a second internal seal (162) extending around at least of portion of the second opening (132). External seals (124,152) may also extend around at least a portion of the body (102).

Description

HYBRID FERRULE BOOT FOR STANDARD AND SMALL OD FIBERSReference to Related Case

[0001] This application claims priority under 35 U.S.C. § 119 (e) to U.S. provisional application no. 63 / 552,710 filed on February 13, 2024, the contents of which are hereby incorporated by reference in their entirety.BACKGROUND OF THE INVENTION

[0002] There is an increase in the need to use smaller outer diameter (OD) optical fibers. The current market utilizes 250 pm optical fibers The general market is migrating to smaller optical fibers, which helps increase the density of optical fibers per jacket.

[0003] The assembly of fiber optic connectors requires the optical fibers are secured within the fiber optic ferrule. The optical fibers are secured by using epoxy, but the epoxy can wick down the optical fibers and onto unintended areas such as the guide pin holes. Therefore, there is usually a boot or a sleeve that keeps the epoxy from wicking into critical areas. If the epoxy leaks out, one has to clean the epoxy, which adds time to the termination process. If cleaning is not possible, the ferrule will have to be cut off and the process of termination will need to restart; a costly endeavor. Additionally, epoxy may wick or leak out during the curing process of the epoxy resulting in cured epoxy in unwanted, critical areas.

[0004] The current boot, sized for the larger (250 micron) optical fibers and factory ribbonized 250 micron fiber, will not prevent epoxy wicking when terminating with smaller OD optical fibers as the clearance between the optical fibers and the ferrule boot is too large. One solution is to have two different sized boots - one for the smaller OD optical fibers and one for the larger OD optical fibers. However, such a scheme would require holding inventory of both boots, keeping track of different sizes, and making sure that the correctly sized one is used, and related issues therewith. To at least address the foregoing issues Applicant has designed a hybrid ferrule boot that allows the use of a broader range of optical fiber diameters using just one ferrule boot, and addresses epoxy wicking issues.SUMMARY OF THE INVENTION

[0005] According to one aspect, the present invention is directed to a ferrule boot for a multi-fiber ferrule that includes a body having a top, a bottom, and two sides connecting the top and the bottom, the body extending longitudinally between a front end and a back end, a first opening in the body extending from the front end toward the back end, a second opening in the body extending longitudinally toward the front end, the first opening and the second opening in communication with each other, and a first internal seal disposed at a junction of the first opening and the second opening, the first internal seal extending around at least of portion of the second opening and narrowing the second opening at the junction of the first opening and the second opening.

[0006] In some embodiments, there is also a third opening extending toward the front end and separated from but parallel to the second opening and also in communication with the first opening, the third opening having a second internal seal disposed at a junction of the first opening and the third opening, the second internal seal extending around at least of portion of the third opening and narrowing the third opening at the junction of the first opening and the third opening.

[0007] In some embodiments, the first opening is configured to be received inside at least a portion of the multi-fiber ferrule and the second opening is configured to receive a plurality of optical fibers.

[0008] In some embodiments, there is also a first external seal extending circumferentially around at least an external portion of the body.

[0009] In some embodiments, the invention also includes a second external seal also extending circumferentially around at least a second external portion of the body.

[0010] In some embodiments, the narrowed second opening is less than 125 microns.

[0011] In some embodiments, the narrowed second opening could have features that extend circumferentially around the fibers further sealing any openings.

[0012] In some embodiments, the first internal seal and the second internal seal extend across the top and the bottom and not along respective sides of the second opening and the third opening.

[0013] In other embodiments, the first internal seal and the second internal seal extend completely around the second opening and the third opening, respectively, at the junctions with the first opening.

[0014] In some embodiments, the second opening and the third opening extend from the back end towards the front end.

[0015] In yet another aspect, there is a ferrule boot for a multi-fiber ferrule that includes a body having a top, a bottom, and two sides connecting the top and the bottom, the body extending between a front end and a back end, a first opening in the body extending from the front end toward the back end to be received in a portion of the multifiber ferrule, a second opening in the body extending toward the front end and terminating rearwardly of the front end, a third opening in the body extending toward the front end and terminating rearwardly of the front end, a first internal seal disposed at the terminated second opening, the first internal seal extending around at least of portion of the second opening and narrowing the second opening, and a second internal seal disposed at the terminated third opening, the second internal seal extending around at least of portion of the second opening and narrowing the second opening.

[0016] In some embodiments, the first opening is configured to be received inside at least a portion of the multi-fiber ferrule and the second opening and the third openings are configured to receive a plurality of optical fibers.

[0017] In yet another aspect, there is a ferrule boot for a multi-fiber ferrule that includes a body having a top, a bottom, and two sides connecting the top and the bottom, the body extending longitudinally between a front end and a back end, a first opening in the body extending from the front end toward the back end, a second opening in the body extending longitudinally rearward from the first opening and in communication with the first opening, and a first internal seal disposed at a junction of the first opening and the second opening, the first internal seal extending around at least of portion of the second opening and narrowing the second opening at the junction of the first opening and the second opening.

[0018] It is to be understood that both the foregoing general description and the following detailed description of the present embodiments of the invention are intended to provide an overview or framework for understanding the nature and character of the invention as it is claimed. The accompanying drawings are included to provide a further understanding of the invention, and are incorporated into and constitute a part of this specification. The drawings illustrate various embodiments of the invention and, together with the description, serve to explain the principles and operations of the invention.BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Fig. l is a top view of one embodiment of a ferrule boot according to the present invention with a multi-fiber ferrule and optical fibers;

[0020] Fig. 2 is cross section of the ferrule boot in Fig. 1 with the optical fibers disposed within the ferrule boot and the multi-fiber ferrule removed for clarity;

[0021] Fig. 3 is an elevational view of the ferrule boot and the optical fibers from the back end thereof;

[0022] Fig. 4 is a cross section of the ferrule boot inserted into the back end of the multi-fiber ferrule;

[0023] Fig. 5 is a perspective view of one embodiment of a ferrule boot according to the present invention from the upper right thereof;

[0024] Fig. 6 is a left side perspective view the ferrule boot in Fig. 1;

[0025] Fig. 7 is a perspective view from the front of the ferrule boot in Fig. 1;

[0026] Fig. 8 is a cross section view of the ferrule boot in Fig. 1 along the line 8-8 inFig. 6;

[0027] Fig. 9 is a cross sectional view of the ferrule boot in Fig. 1 along the line 9-9 in Fig. 6;

[0028] Fig. 10 is an elevational view of the ferrule boot in Fig. 1 from the front left;

[0029] Fig. 11 is a cross section of a second embodiment of a ferrule boot according to the present invention;

[0030] Fig. 12 is a perspective view of a third embodiment of a ferrule boot according to the present invention;

[0031] Fig. 13 is a cross section view of the ferrule boot in Fig. 12;

[0032] Fig. 14 is a cross section view of the ferrule boot in Fig. 12;

[0033] Fig. 15 is a top view of a fourth embodiment of a ferrule boot according to the present invention with a multi-fiber ferrule and optical fibers;

[0034] Fig. 16 is a cross section of the ferrule boot in Fig. 15 with the optical fibers disposed within the ferrule boot and the multi-fiber ferrule removed for clarity;

[0035] Fig. 17 is an elevational view of the ferrule boot in Fig. 15 from the back end thereof;

[0036] Fig. 18 is a perspective view of the ferrule boot in Fig. 15;

[0037] Fig. 19 is a partial cross section view of the ferrule boot in Fig. 15;

[0038] Fig. 20 is a partial cross section view of the ferrule boot in Fig. 15; and

[0039] Fig. 21 is a rear view of another embodiment of a ferrule boot with curved portions to engage the optical fibers.DETAILED DESCRIPTION OF THE INVENTION

[0040] Reference will now be made in detail to the present preferred embodiment(s) of the invention, examples of which are illustrated in the accompanying drawings. Whenever possible, the same reference numerals will be used throughout the drawings to refer to the same or like parts.

[0041] Illustrated in Figs. 1 - 9 is one embodiment of a ferrule boot 100 for a multifiber ferrule 10. Also present in Fig. 1 are a number of optical fibers 12 that extend through the ferrule boot 100 and into (and through) the multi-fiber ferrule 10. The multifiber ferrule 10 illustrated in Figs. 1 and 3 is an MT ferrule, but the ferrule boot 100 may be used in a number of other different multi-fiber ferrules (e.g., the TMT ferrule provided by the Applicant). The ferrule boot 100 can be used with multi-fiber ferrules that use epoxy or other adhesive, where the epoxy can interfere with the operation of the components used with the multi-fiber ferrules 10. As illustrated in Figs. 3 and 4, the ferrule boot 100 is inserted into the back end of the multi-fiber ferrule 10. See also Fig. 16.

[0042] Applicant notes that the term “front” or “forward” means that direction where the fiber optic ferrule would meet with another fiber optic ferrule or device, while the term “rear” or “rearward” is used to mean the direction from which the optical fibers enter into the fiber-optic ferrule or fiber optic connector. In the present application, the ferrule boot 100 will therefore have a front and a rear, the front will be inserted into the rear of the multi-fiber ferrule 10. See also Fig. 15. Thus, in Fig. 1, the “front” of the ferrule boot 100 (and also the multi-fiber ferrule 10) is on the right side of the figure and pointing out the side of the page. The “rear” or “back” is that part of the ferrule boot 100 (or the multi-fiber ferrule 10) is on the left side of the figure and “rearward” and “backward” is toward the left.

[0043] Turning now to Figs. 4-9, the ferrule boot 100 will be described. The ferrule boot 100 may be referred to as a hybrid ferrule boot, the term “hybrid” relating to theferrule boot 100 being capable of receiving standard 250micron OD fibers, 250 micron OD fiber having a factory ribbon form, or smaller OD fibers (e.g., 125 microns or less). The ferrule boot 100 has a body 102, a top 104, a bottom 106, and two sides 108,110. The two sides 108,110 connect the top 104 and the bottom 106. The body 102 also has a front end 112 and a back end 114 and the body 102 extends longitudinally between the front end 112 and the back end 114 along longitudinal axis A. See Figs. 4 and 5. The body 102 also has an external surface 120 and, as described more in detail below, has a first external portion 122 where a first external seal 124 extends circumferentially around at least a portion of the body 102.

[0044] The body 102 has a first opening 130 that extends rearwardly toward the back end 114 from the front end 112 and is at least partially formed by the top 104, the bottom 106, and the two sides 108,110. See also Fig. 2. The body 102 also has a second opening 132 that extends longitudinally toward the front end 112. The first opening 130 and the second opening 132 are in communication with each other at a junction 134 of the first opening 130 and the second opening 132. See Fig. 7. The second opening 132 has a configuration that is more of an oval or rectangular to receive the optical fibers 12. In this respect, the second opening 132 forms a first channel for a row of fibers 12 to be terminated inside the multi-fiber ferrule 10. The optical fibers may be loose or individual optical fibers or in a ribbon format joined together. See Figs. 3, 5, 7, and 10. The configuration of the second opening 132 assists in keeping the optical fibers 12 in a row.

[0045] The body 102 also has a third opening 140 that extends longitudinally toward the front end 112. The first opening 130 and the third opening 140 are in communication with each other at a junction 142 of the first opening 130 and the third opening 140. In this respect, the third opening 140 forms a second channel for another row of fibers 12 to be terminated inside the multi-fiber ferrule 10, which makes the multi-fiber ferrule 10 a multi-row ferrule too. The third opening 140 is separated from but parallel to the second opening 132. The third opening 140 is also identical in construction to the second opening 132. See Figs. 7-10. In one embodiment, the second opening 132 and the third opening 140 extend from the first opening 130 to the back end 114. See Figs. 3-8. The configuration of the third opening 140 also assists in keeping the optical fibers 12 in a row. Thus , there is at least one of the second opening 132 or the third opening 140 inside the body 102 of the ferrule boot 100. Further, each of the second opening 132 and thethird opening 140 may not extend all the way to the back end 114 of the ferrule boot 100, and may stop short thereof. Likewise, each of the second opening 132 and the third opening 140 may extend all the way to the front end 112, making the first opening 130 optional or non-existent.

[0046] In an alternative embodiment, see Fig. 11, there is a ferrule boot 100’ that has a second opening 132’ and a third opening 140’ that only extend as separate openings partially toward the back end 114’ and then join together to create a larger opening 144’. The larger opening 144’ can extend farther into the body 102’ (toward the front end 112’) than illustrated in Fig. 11, but may also be shorter. The dividing portion 146’ may take other forms than that shown in Fig. 11. The back end 148’ of the dividing portion 146’ may be more rounded, or more tapered than is illustrated.

[0047] The ferrule boot 100’ may not have a first opening, opting for a truncated front end 112’ where the second opening 132’ and the third opening 140’ extend through the body 102’.

[0048] Referring back to Figs. 1-10, the ferrule boot 100 has a number of seals to prevent the adhesive / epoxy from wi eking down the optical fibers 12 and contaminating a fiber optic connector in which they are installed. There are, in this embodiment, internal seals and external seals. The first external seal 124 extends circumferentially around at least a portion of the body 102 at the first external portion 122. See Fig. 6. The first external seal 124 is configured to engage an inside surface 150 of the multi-fiber ferrule 10. See Figs. 2 and 4. In one embodiment, the first external seal 124 extends circumferentially around the entirety of ferrule boot 100, but it may also extend around less than the entirety of the body 102. Rearward of the first external seal 124 is a second external seal 152 at a second external portion 154. The second external seal 152 extends circumferentially around at least a portion of the body 102 at the second external portion 154. The second external seal 152 is also configured to engage an inside surface 150 of the multi-fiber ferrule 10, preferably at the rear end of the multi-fiber ferrule 10. See Figs. 2 and 4. Alternatively, the second internal seal 152 may be optional or non-existent.

[0049] There are also the internal seals, a first internal seal 160 is at the junction 134 of the first opening 130 and the second opening 132, and a second internal seal 162 is at the junction 142 of the first opening 130 and the third opening 140. See Figs. 7-10. In this embodiment, the internal seals 160,162 are divided into two portions 160a, 160b and162a, 162b. The portions 160a, 160b extend across the top and the bottom, respectively, of the first opening 132 at the junction 134 of the first opening 130 and the second opening 132. See Figs 4-10. The two portions 160a, 160b are directed to or face each other, thereby narrowing the second opening 132 at the junction 134 to less than 125 microns. The two portions 160a, 160b of the first internal seal 160 preferably do not touch each other inside or adjacent the sides 108, 110 of the ferrule boot 100. See Figs. 7, 9, and 10.

[0050] The same is true with the two portions 162a, 162b of second internal seal 162, which is at the junction 134 of the first opening 130 and the third opening 140. That is, the first portion 162a does not touch the second portion 162b inside or adjacent the sides 108, 110 of the ferrule boot 100. The spacing between the two portions 160a, 160b and 162a, 162b allows for the two portions 162a, 162b to be more flexible and to conform more to the optical fibers 12. This flexibility allows for accommodating differently sized fibers with the same ferrule boot 100 as the two portions 160a, 160b and 162a, 162b can change. In one alternative implementation shown in Fig. 21, there is another ferrule boot 400 with an internal seal 460 that is made of two portions 460a, 460b that may instead have curved parts 426 to match a geometry of the optical fibers in the ribbon.

[0051] Another embodiment of a ferrule boot 200 according to the present invention is illustrated in Figs. 12-14. The ferrule boot 200 is constructed in the same way as ferrule boot 100, except that the first internal seal 260 and the second internal seal 262 both go all the way around the second opening 232 and the third opening 240 at their junctions with the first opening, respectively, without any breaks. If the first internal seal 260 and the second internal seal 262 are pliable enough, their presence at the side portions (near the sides 208 and 210) will not affect their ability to stop the wicking of the epoxy / adhesive.

[0052] Another embodiment of a ferrule boot 300 according to the present invention is illustrated in Figs. 15-19. In this embodiment, the ferrule boot 300 is significantly shorter than the ferrule boot 100, and it only has two openings, rather than the three openings in the ferrule boot 100.

[0053] The ferrule boot 300 has a body 302, a top 304, a bottom 306, and two sides 308,310. The two sides 308,310 connect the top 304 and the bottom 306. The body 302 also has a front end 312 and a back end 314 and the body 302 extends longitudinallybetween the front end 312 and the back end 314 along longitudinal axis B. See Fig. 18. The body 302 also has an external surface 320 and, as described more in detail below, has a first external portion 322 where a first external seal 324 extends circumferentially around at least a portion of the body 302.

[0054] The body 302 has a first opening 330 that extends rearwardly toward the back end 314 from the front end 312 and is at least partially formed by the top 304, the bottom 306, and the two sides 308,310. The body 302 also has a second opening 332 that extends longitudinally toward the front end 312. The first opening 330 and the second opening 332 are in communication with each other at a junction 334 of the first opening 330 and the second opening 332. The second opening 332 has a configuration that is more of an oval or rectangular to receive the optical fibers 12. The optical fibers 12 may be loose or individual optical fibers or in a ribbon format. See Figs. 15-17. The configuration of the second opening 332 assists in keeping the optical fibers 12 in a row. The second opening 332 is preferably centered between the top 304 and the bottom 306 as well as between the sides 308,310. See Figs. 16 and 17. The second opening 332 may also be larger at the back end of the ferrule boot 300.

[0055] The ferrule boot 300 has three seals to prevent the adhesive / epoxy from wicking down the optical fibers 12. There are, in this embodiment, two external seals and one internal seal. The first external seal 324 extends circumferentially around at least a portion of the body 302 at the first external portion 322. The first external seal 324 is configured to engage an inside surface 150 of the multi-fiber ferrule 10. See Fig. 16. In one embodiment, the first external seal 324 extends circumferentially around the entirety of ferrule boot 300, but it may also extend around less than the entirety of the body 302. Rearward of the first external seal 324 is a second external seal 352 at a second external portion 354. The second external seal 352 extends circumferentially around at least a portion of the body 302 at the second external portion 354. The second external seal 352 is configured to engage an inside surface 150 of the multi-fiber ferrule 10, preferably at the rear end of the multi-fiber ferrule 10. See Fig. 16. Alternatively, only one external seal may be provided.

[0056] There is also one internal seal - a first internal seal 360 is at the junction 334 of the first opening 330 and the second opening 332. See Figs. 16 and 18-20. The first internal seal 360 is directed toward the first opening 330 and narrows the second opening332 to less than 250 microns. As illustrated, the first internal seal 360 completely encircles the opening 332, but it could be broken up into two or more portions.

[0057] It will be apparent to those skilled in the art that various modifications and variations can be made to the present invention without departing from the spirit and scope of the invention. Thus it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.

Claims

IN THE CLAIMS:We claim:

1. A ferrule boot for a multi-fiber ferrule comprising: a body having a top, a bottom, and two sides connecting the top and the bottom, the body extending longitudinally between a front end and a back end; a first opening in the body extending from the front end toward the back end; a second opening in the body extending longitudinally toward the front end, the first opening and the second opening in communication with each other; and a first internal seal disposed at a junction of the first opening and the second opening, the first internal seal extending around at least of portion of the second opening and narrowing the second opening at the junction of the first opening and the second opening.

2. The ferrule boot according to claim 1, further comprising a third opening extending toward the front end and separated from but parallel to the second opening and also in communication with the first opening, the third opening having a second internal seal disposed at a junction of the first opening and the third opening, the second internal seal extending around at least of portion of the third opening and narrowing the third opening at the junction of the first opening and the third opening.

3. The ferrule boot according to claim 1, wherein the first opening is configured to be received inside at least a portion of the multi-fiber ferrule and the second opening is configured to receive a plurality of optical fibers4. The ferrule boot according to claim 1, further comprising a first external seal extending circumferentially around at least an external portion of the body.

5. The ferrule boot according to claim 4, further comprising a second external seal also extending circumferentially around at least a second external portion of the body.

6. The ferrule boot according to claim 1, wherein the narrowed second opening is less than 125 microns.

7. The ferrule boot according to claim 2, wherein the first internal seal and the second internal seal extend across the top and the bottom and not along respective sides the second opening and the third opening.

8. The ferrule boot according to claim 2, wherein the first internal seal and the second internal seal extend completely around the second opening and the third opening, respectively, at the junctions with the first opening.

9. The ferrule boot according to claim 1, wherein the second opening extends from the back end towards the front end.

10. The ferrule boot according to claim 2, wherein the third opening extends from the back end towards the front end.

11. A ferrule boot for a multi-fiber ferrule comprising: a body having a top, a bottom, and two sides connecting the top and the bottom, the body extending between a front end and a back end; a first opening in the body extending from the front end toward the back end to be received in a portion of the multi-fiber ferrule; a second opening in the body extending toward the front end and terminating rearwardly of the front end; a third opening in the body extending toward the front end and terminating rearwardly of the front end; a first internal seal disposed at the terminated second opening, the first internal seal extending around at least of portion of the second opening and narrowing the second opening; and a second internal seal disposed at the terminated third opening, the second internal seal extending around at least of portion of the third opening and narrowing the third opening.

12. The ferrule boot according to claim 11, wherein the first opening is configured to be received inside at least a portion of the multi-fiber ferrule and the second opening and the third opening are configured to receive a plurality of optical fibers.

13. The ferrule boot according to claim 11, further comprising a first external seal extending circumferentially around at least an external portion of the body.

14. The ferrule boot according to claim 13, further comprising a second external seal also extending circumferentially around at least a second external portion of the body.

15. The ferrule boot according to claim 11, wherein the narrowed second opening is less than 125 microns.

16. The ferrule boot according to claim 11, wherein the second internal seal and the third internal seal extend across the top and the bottom and not along sides of the second opening and the third opening, respectively.

17. The ferrule boot according to claim 11, wherein the second internal seal and the third internal seal extend completely around the second opening and the third opening, respectively, at the junctions with the first opening.

18. The ferrule boot according to claim 11, wherein the second opening extends from the back end towards the front end.

19. The ferrule boot according to claim 11, wherein the third opening extends from the back end towards the front end.

20. A ferrule boot for a multi-fiber ferrule comprising: a body having a top, a bottom, and two sides connecting the top and the bottom, the body extending longitudinally between a front end and a back end; a first opening in the body extending from the front end toward the back end;a second opening in the body extending longitudinally rearward from the first opening and in communication with the first opening; and a first internal seal disposed at a junction of the first opening and the second opening, the first internal seal extending around at least of portion of the second opening and narrowing the second opening at the junction of the first opening and the second opening.

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