Fiber optic splice organizer and associated method

A fiber optic splice organizer for storing optical fiber splices and the slack associated therewith to permit ready separation of the optical fibers, such as to remake a splice. The splice organizer includes a generally rectangular base, splice securing slots on the base, and optical fiber guides for guiding slack portions of first and second optical fiber groups from a first end of the base, along respective portions of the base adjacent the first and second sides thereof, into a plurality of overlying slack loops adjacent the second end of the base, and back to the splice securing means from respective first and second sides of the base. The slack optical fibers, including the overlying respective slack loop, of the first and second optical fiber groups, form a figure-eight pattern on the base and are thus readily separable from each other. An ability to interconnect individual optical fibers broken out from optical fiber ribbons is also provided by crossing first and second groups of optical fiber ribbons and breaking out individual optical fibers at the crossover point. Arcuately shaped walls on the base are provided to maintain the individual fibers in a predetermined bend radius. A series of tabs along sidewalls of the base separate the individual fibers from the optical fiber ribbons downstream from the crossover point.

FIELD OF THE INVENTION 
The invention relates to the field of fiber optics and, more particularly, 
to the storage and organization of fiber optic splices and associated 
slack. 
BACKGROUND OF THE INVENTION 
Optical fiber communications systems are used extensively in the 
telecommunications industry due to their large information carrying 
capacity, their virtually noise-free performance, and the long span 
distances achievable with optical fibers before regeneration and 
amplification of the signal is required. Practical limits on the lengths 
of optical fiber cables that can be manufactured and installed typically 
require that many splice points be included over the total cable route. 
At each splice location, the optical fibers are separated from 
The invention relates to the field of fiber optics and, more particularly, 
to the storage and organization of fiber optic splices and associated 
slack. 
BACKGROUND OF THE INVENTION 
Optical fiber communications systems are used extensively in the 
telecommunications industry due to their large information carrying 
capacity, their virtually noise-free performance, and the long span 
distances achievable with optical fibers before regeneration and 
amplification of the signal is required. Practical limits on the lengths 
of optical fiber cables that can be manufactured and installed typically 
require that many splice points be included over the total cable route. 
At each splice location, the optical fibers are separated from the other 
protective cable components for splicing and are, thus, more susceptible 
to damage. In addition, the optical fibers at a splice point are handled 
by a technician who must splice the fibers and then store the splice and 
associated slack in a protective enclosure. 
Accordingly, enclosures for protecting optical fiber splices have been 
developed and are readily available. Typically, these enclosures include 
one or more splice organizers, or splice trays, on which the individual 
splices and associated slack are mounted. For example, the assignee of the 
present invention manufactures a conventional splice enclosure and splice 
organizer under the model designation FOSC 100. Siecor Corporation of 
Hickory, N.C. makes splice enclosures under the model designations SC2, 
and SC4-6. Another splice enclosure is shown in UK Patent Application No. 
2,150,313A assigned to Preformed Line Products of Cleveland, Ohio. 
A splice organizer is typically limited in the amount of space it may 
occupy although it must permit the mounting of the individual splices and 
permit storage of the slack optical fibers in a relatively neat 
configuration. To hold a sufficient amount of slack to permit splicing, a 
splice organizer typically accommodates one or more bends of slack optical 
fiber in slack loops that cannot be sharply bent and thereby exceed the 
minimum bend radius for the optical fiber. Exceeding the bend radius 
causes microbending losses, that is, increased attenuation of the optical 
signal. In addition, the optical fibers may be physically damaged by 
exceeding the minimum bend radius. An approach to storing a sufficient 
length of slack, is to use multiple loops for each individual fiber. See, 
for example, U.S. Pat. No. 4,373,776, to Purdy, and U.S. Pat. No. 
4,765,709 to Suillerot et al. 
The slack loops of conventional splice organizers are frequently 
permanently entangled with each other as part of the normal course of 
splicing and routing of the slack for storage on the splice organizer. 
Unfortunately, it is very difficult to access an individual splice after 
all of the splices have been completed because of the entangling of the 
slack optical fibers. In almost all fiber optic communications systems, it 
is critical that high quality and high reliability splices be obtained. 
Fusion and mechanical splicing techniques and equipment have been 
developed that permit low loss, high quality, and durable splices to be 
obtained. However, it may sometimes be necessary to remake or repair 
splices to achieve the desired splice quality. The inability to readily 
reaccess a splice, such as to remake the splice, is a significant 
shortcoming of conventional fiber optic splice organizers. 
Fiber cables are also available of a ribbon type, such as manufactured by 
AT&T, wherein several optical fibers are arranged in side-by-side relation 
and secured together by an adhesive layer. However, another difficulty 
with conventional splice organizers and techniques is that organizers for 
ribbon-type fiber optic cables require that every fiber in a given ribbon 
be spliced to every correspondingly positioned fiber of another fiber 
optic ribbon. Thus, any flexibility in interconnecting a predetermined 
individual optical fiber to an optical fiber in a different position or on 
a different ribbon is simply not available. Moreover, should it be 
necessary to repair only a single optical fiber splice of the ribbon, all 
of the splices must then be broken and remade. Thus, unnecessary 
communications system downtime is experienced because of the need to work 
with all of the fibers in the ribbon, rather than being able to 
efficiently access only one optical fiber from the ribbon. 
In many new fiber optic communications applications, such as in campus-type 
networks or cable TV networks, high fiber counts and a large number of 
drop points are required. Unfortunately, since conventional fiber optic 
organizers cannot accommodate splices between individual optical fibers 
when ribbon cables are used, interconnection flexibility for such a system 
is severely limited. 
OBJECTS AND SUMMARY OF THE INVENTION 
In view of the foregoing background, it is therefore an object of the 
present invention to provide a splice organizer and method for securing 
optical fiber splices and slack associated therewith that also permits 
ready separation of the optical fibers even after all of the splices have 
been completed, such as to facilitate remaking a splice. 
Another object of the invention is to provide a splice organizer and method 
for optical fiber ribbons which permits the break out and splicing of 
individual optical fibers from the ribbons to enhance interconnection 
flexibility and to permit the repair of individual optical fibers from an 
optical fiber ribbon. 
These and other objects, advantages and features according to the invention 
are provided by a splice organizer including a generally rectangular base, 
splice securing means on the base, and slack guide means on the base for 
guiding respective slack portions of first and second optical fiber groups 
from a first end of the base, along respective portions of the base 
adjacent the first and second sides thereof, into a plurality of overlying 
slack loops adjacent the second end of the base, and back to the splice 
securing means from respective first and second sides of the base. The 
slack, including the overlying respective slack loops of the first and 
second optical fiber groups, form a figure-eight pattern on the base and 
are thus readily separable from each other. Accordingly, splices between 
optical fibers in high fiber count cables can be readily accommodated, 
and, if necessary, a single splice and its associated slack may be readily 
separated from the others, such as to permit remaking a defective splice. 
Ribbon optical fiber cables are also advantageously used with the splice 
organizer. 
The splice organizer may be adapted for an in-line splice or a butt splice. 
As would be readily understood by those skilled in the art, for an in-line 
splice the two optical fiber cables are secured to opposite ends of the 
base and the routing of the overlying slack loops are the same as for the 
butt splice. 
The slack guide means for the splice organizer preferably includes first 
and second pairs of laterally spaced apart optical fiber guides positioned 
adjacent respective first and second sides of the base. Each of these 
first and second pairs of optical fiber guides includes first and second 
optical fiber guides, wherein the first optical fiber guide of each pair 
is positioned on a medial portion of the base between the first and second 
ends thereof and the second optical fiber guide of each pair is positioned 
adjacent the second end of the base. Each of the optical fiber guides is 
preferably formed by a pair of opposing spaced apart walls extending 
upwardly from the base. An additional pair of laterally spaced apart 
optical fiber guides and associated fasteners are preferably provided 
adjacent the first end of the base and further serve to hold the optical 
fiber groups to the base. 
The splice securing means is preferably provided by a series of laterally 
spaced apart walls extending upwardly from the base. The spaced apart 
walls thereby define a series of widthwise extending slots for receiving 
conventional optical fiber splices therein. 
A further aspect of the present invention is the ability to permit 
interconnecting predetermined individual optical fibers broken out from 
groups of optical fiber ribbons or to repair an individual optical fiber 
in a ribbon. An optical fiber ribbon typically contains four, six, twelve 
or more, side-by-side optical fibers secured together by an adhesive 
layer. Optical fiber ribbons are typically spliced as a unit; however, the 
present invention permits individual fibers to be broken out from the 
ribbons to be repaired, or to be spliced to other optical fibers either in 
a different position or on another ribbon. Thus, the invention provides 
greater flexibility in interconnecting ribbon optical fiber cables and 
facilitates the repair of individual optical fibers in optical fiber 
ribbons. 
The ability to interconnect and splice individual optical fibers is 
provided by breakout means positioned on the base for securing the first 
and second optical fiber ribbon groups and for guiding predetermined 
individual optical fibers broken out from optical fiber ribbons away from 
the ribbons for effecting individual splices. The breakout means for the 
butt splice embodiment of the invention includes crossover means 
positioned adjacent the first end of the base for guiding the first and 
second optical fiber ribbon groups in a crossing relation to positions 
adjacent respective opposing sides of the base. The crossover means 
includes the pair of laterally spaced apart optical fiber ribbon guides 
and fasteners forming the optical fiber group securing means described 
above for holding the optical fiber groups in place on the base. The 
optical fiber ribbon groups are brought along the underside of the base 
and in crossing relation at the first end of the base to the upper surface 
of the base. 
The individual fibers are broken out from the ribbons at the crossing point 
and guided along first and second arcuately shaped walls positioned on the 
base adjacent respective optical fiber ribbon guides. The arcuately shaped 
walls each have a predetermined radius of curvature for maintaining the 
individual optical fibers at a predetermined minimum bend radius. As would 
be readily understood by those skilled in the art, exceeding the minimum 
bend radius of an optical fiber causes undesirable microbending losses for 
the optical signal carried by the optical fiber and jeopardizes the 
physical integrity of the optical fiber groups. 
Separator means for maintaining the individual optical fibers separate from 
the first and second optical fiber ribbon groups is provided downstream 
from the breakout means. The separator means is provided by first and 
second channels on the base extending lengthwise adjacent respective first 
and second sides of said base for receiving therein slack portions of the 
predetermined individual optical fibers. A generally widthwise extending 
arcuately shaped wall, having a predetermined radius of curvature, is also 
positioned on the base adjacent the second end thereof to maintain the 
individual optical fibers and ribbons separated. 
The method according to the present invention for organizing optical fiber 
splices and their associated slack includes the steps of guiding and 
securing respective slack portions of first and second optical fiber 
groups from the first end of the base, along respective portions of the 
base adjacent the first and second sides thereof, into a plurality of 
overlying slack loops adjacent the second end of said base, and back to 
adjacent the first end of the base from respective first and second sides 
of the base. The optical fiber splices are then secured on a medial 
portion of the base adjacent the first end thereof. 
A method according to the present invention for splicing optical fiber 
ribbon groups includes the steps of breaking out predetermined individual 
optical fibers from predetermined optical fiber ribbons and splicing the 
thus broken out predetermined individual optical fibers. The remaining 
fibers in the optical fiber ribbon groups are also spliced. These steps 
are advantageously combined with the slack routing and organizing method 
steps described in the preceding paragraph. Thus, several major 
shortcomings of conventional splice organizers and methods are overcome by 
the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
The present invention will now be described more fully hereinafter with 
reference to the accompanying drawings, in which preferred embodiments of 
the invention are shown. This invention may, however, be embodied in many 
different forms and should not be construed as limited to the embodiments 
set forth herein; rather, applicants provide these embodiments so that 
this disclosure will be thorough and complete, and will fully convey the 
scope of the invention to those skilled in the art. Prime notation is used 
to identify to like elements of alternate embodiments. 
A completed fiber optic butt splice 20 is shown in FIG. 1 with the fiber 
optic splice organizer 21 according to the present invention shown 
installed within a protective housing 22. The fiber optic butt splice 20 
includes portions of two fiber optic cables 24, 25 entering through an 
opening in an end cap 26 of the butt splice 20. The protective housing 22 
is sealed to the end cap 26 after the splicing operation is completed. A 
mounting bracket 27 secures the splice organizer 21 to the end cap 26. The 
fiber optic butt splice 20 may be installed aerially along a pole line, in 
a manhole, direct buried in the ground, and in other locations as would be 
understood by those having skill in the art. As will also be readily 
appreciated by those skilled in the art the present invention is 
advantageously used in other splice configurations, such as an in-line 
splice wherein a pair of fiber optic cables enter the housing through 
respective opposing end caps. 
Referring first to FIGS. 2 and 3, the two embodiments of the splice 
organizer 21, 21' according to the invention are best understood. In FIG. 
2 there is shown a splice organizer 21 for a butt-type splice wherein both 
fiber cables 24, 25 enter the splice enclosure 20 (FIG. 1) from one end 
cap 26. FIG. 3 shows an alternate embodiment of the splice organizer 21' 
for an in-line splice wherein two cables 24, 25 enter the splice enclosure 
from opposing end caps and are thus secured to the splice organizer 21' at 
opposing first and second ends of the base 30'. In view of the similarity 
of the two embodiments shown in FIGS. 2 and 3, the following description 
will be directed to the embodiment shown in FIG. 2 for the butt-type 
splice; it being readily understood therefrom by those skilled in the art 
the operation of the in-line splice organizer shown in FIG. 3. 
Letters A and B are used in the various drawing figures for clarity in 
describing the elements of the invention on first and second lengthwise 
extending sides, respectively, of the splice organizer 21. The splice 
organizer 21 includes a generally rectangular base 30 having lengthwise 
extending first and second opposing sides (A, B) and widthwise extending 
first and second opposing ends. The first end of the base 30 is defined as 
the end opposite from the mounting bracket 27 while the second end of the 
base is adjacent the mounting bracket. The base 30 is preferably made of a 
plastic material and is generally rectangular in shape. By generally 
rectangular is meant that the base 30 may be square, or may have rounded 
or cut-off corners and thus appear somewhat elliptical in shape. 
Referring now to FIGS. 2-5, splice securing means 31 is positioned on a 
medial portion of the base between the first and second sides thereof and 
adjacent the first end of the base for securing a plurality of optical 
fiber splices 39, 34 on the base 30. As shown in the illustrated 
embodiment of FIG. 4, the splice securing means may be provided by a 
series of laterally spaced apart walls 35 extending upwardly from the base 
30 and being integrally molded with the base to thereby define a series of 
widthwise extending slots for receiving optical fiber splices therein. 
As shown best in the exploded view of FIG. 4, a conventional ribbon optical 
fiber splice holder 33 as used in the present invention includes a first 
clip 36 which is secured to the splice retaining means 31 by screws 37, 
and a second clip 38 which matingly engages the first clip 36 and also 
retains a plurality of individual ribbon optical fiber splices, each 
surrounded by a protective sleeve 39. The individual optical fiber splices 
34 (FIGS. 2 and 4) are also of a conventional type, wherein the fiber ends 
are either mechanically held in alignment or fusion welded, and housed 
within protective sleeves, not shown. 
The splice organizer 21 also includes slack guide means positioned on the 
base 30 for guiding respective slack portions of laterally spaced apart 
first and second optical fiber groups 40A, 40B from the first end of the 
base, along respective portions of the base adjacent the first and second 
sides thereof, into a plurality of overlying slack loops adjacent the 
second end of the base, and back to splice securing means 31 from 
respective first and second sides of the base. Accordingly, overlying 
respective slack loops of first and second optical fiber groups are 
readily separable from each other. This feature of the invention is 
achieved by the guide means in both the in-line splice embodiment of the 
invention shown in FIG. 3 and the butt splice embodiment illustrated in 
the other drawing figures. 
As shown in the illustrated embodiment of FIG. 2, the slack guide means may 
be provided by first and second pairs of laterally spaced apart optical 
fiber guides 42A, 42B positioned adjacent respective first and second 
sides of the base 30. The first optical fiber guide of each pair is 
positioned on a medial portion of the base between the first and second 
ends thereof, and the second optical fiber guide of each pair is 
positioned adjacent the second end of the base. Each of optical fiber 
guides 42A, 42B is formed by a pair of opposing spaced apart walls 
extending upwardly from the base. To secure the respective optical fiber 
groups 40A, 40B within the optical fiber guides 42A, 42B, fasteners (not 
shown) may be used to close the open upper ends of the optical fiber 
guides 42A, 42B after splicing is completed, as would be readily 
understood by those skilled in the art. 
Optical fiber group securing means is also positioned on the base adjacent 
the first end thereof for securing the first and second optical fiber 
groups 40A, 40B in laterally spaced apart relation on the base 31 upstream 
from the guide means and adjacent respective first and second sides of the 
base. The optical fiber group securing means includes a pair of laterally 
spaced apart optical fiber guides 45A, 45B and a pair of associated 
fasteners 46A, 46B. 
Referring now to FIGS. 8-11, the freedom from entanglement between fibers 
in the respective optical fiber ribbon groups 40A, 40B and ease of 
subsequent access obtained with the splice organizer 21 are best 
explained. FIG. 8 illustrates a conventional ribbon optical fiber splice 
and protective sleeve 39 after completion of the splice wherein an optical 
fiber ribbon 40A", 40B" from each optical fiber ribbon group 40A, 40B is 
shown routed away from the splice organizer 21 to the splicing location. 
The splicing location is typically a conventional splicing tool for 
precisely aligning the optical fiber ends and securing them in the aligned 
position. As would be readily understood by those skilled in the art, 
single optical fiber ribbons or individual optical fibers may be spliced 
and routed as shown in FIG. 8. 
In FIG. 9, the slack optical fibers 40A", 40B" to the made splice and 
protective sleeve 39 are shown routed through the pairs of optical fiber 
guides 42A, 42B so as to form a pair of overlying slack loops adjacent the 
second end of the base 30. Each splice and protective sleeve 39, and the 
slack may thus be stored on the splice organizer 21 in a sequential 
fashion as shown in FIGS. 8 and 9 without any permanent entangling between 
the two optical fiber ribbon groups 40A, 40B. 
Referring to FIGS. 10 and 11, one method for accessing a made splice after 
all of the splices have been completed is shown. As shown in FIG. 10, the 
optical fiber ribbon groups 40A, 40B are readily removed from the pairs of 
optical fiber guides 42A, 42B leaving two separate slack loops. In FIG. 
11, an individual splice and its protective sleeve 39 and its associated 
slack 40A", 40B" have been separated from the slack loops of FIG. 10, such 
as for remaking a bad splice. After completing the splice, the optical 
fiber ribbon groups 40A, 40B may then be repositioned within the optical 
fiber guides 42A, 42B. Thus, the present invention permits ready access to 
an individual splice even after all of the splices have been made and the 
slack secured on the splice organizer 21. 
As would be readily understood by those having skill in the art, another 
method for repairing or remaking a bad splice would be to remove only the 
desired optical fiber ribbon 40A", 40B" from the optical fiber guides 42A, 
42B. This subsequent separation and handling of a desired optical fiber 
ribbon is readily facilitated by the present invention because no 
permanent entanglement of the optical fiber ribbon groups or ribbons 
within each group occurs. 
Another significant aspect of the present invention is the ability to break 
out individual optical fibers from optical fiber ribbons and store the 
splices for both, as well as the slack associated with both types of 
splices. 
Referring again to FIGS. 1-2 and 4-7, the break out of individual optical 
fibers from optical fiber ribbons for the butt splice embodiment of the 
invention will be explained. FIGS. 6 and 7 show an optical fiber ribbon 
40A" in cross-section and illustrate the removal of an interior optical 
fiber 50 from the side-by-side optical fibers secured together by an 
adhesive layer 51 surrounding the optical fibers as in a conventional 
ribbon cable of the type manufactured by AT&T. 
As shown best in FIGS. 2 and 5, the splice organizer 21 includes breakout 
means positioned on the base 30 for securing the first and second optical 
fiber ribbon groups 40A, 40B on the base and for guiding predetermined 
individual optical fibers 50 broken out from optical fiber ribbons away 
therefrom for effecting splicing. The breakout means includes crossover 
means 51 positioned adjacent the first end of base 30 for guiding the 
first and second optical fiber ribbon groups 40A, 40B in a crossing 
relation to positions adjacent respective opposing sides of the base. The 
crossover means includes the optical fiber ribbon group securing means, 
that is, the pair of laterally spaced apart optical fiber ribbon guides 
45A, 45B and their associated fasteners 46A, 46B as described above. 
The breakout means further includes first and second arcuately shaped walls 
56A, 56B positioned on the base 30 adjacent respective optical fiber 
ribbon guides 45A, 45B and extending upwardly from the base. Each of the 
first and second arcuately shaped walls has a predetermined radius of 
curvature for maintaining the individual optical fibers at a predetermined 
minimum bend radius. Third and fourth arcuately shaped walls 57A, 57B of 
the crossover means are also provided to guide the optical fiber ribbon 
groups 40A, 40B and maintain them at a sufficiently large predetermined 
bend radius. 
Separator means is provided on the base 30 for maintaining the individual 
optical fibers 50 separate from the first and second optical fiber ribbon 
groups 40A, 40B downstream from the breakout means to thereby prevent 
entangling between the individual optical fibers and the optical fiber 
ribbon groups. The separator means includes first and second channels on 
the base 30 extending lengthwise adjacent respective first and second 
sides of the base for receiving therein slack portions of the individual 
optical fibers 50. The first and second channels are formed by respective 
lengthwise extending side walls 60A, 60B extending upwardly from the base 
30 adjacent the first and second sides of the base and a series of 
laterally spaced apart tabs 61A, 61B connected to upper portions of the 
side walls 60A, 60B. The tabs 61A, 61B extend inwardly from respective 
first and second sides of the base to define the channels for receiving 
the individual optical fibers 50. 
The separator means further includes a generally widthwise extending 
arcuately shaped wall 62 having a predetermined radius of curvature and 
extending upwardly from the base 30 adjacent the second end thereof. The 
individual optical fibers 50 are stored on the inside of the separator 
wall 62, while the optical fiber ribbon groups are stored on the outside 
of the separator wall. 
Splice securing means for the individual optical fibers 50 is provided by 
the series of laterally spaced apart walls extending upwardly from a 
medial portion of the base as shown in FIG. 4. 
As would be readily understood by those skilled in the art, an in-line 
splice according to the invention may also include breakout means for 
separating out individual optical fibers from the optical fiber ribbon 
groups 40A, 40B. An in-line arrangement, however, would not require the 
crossover means as described for the butt-type splice. The separator means 
and the splice securing means for the in-line splice may be similar to 
that for the butt-type splice 20. 
In view of the foregoing description of the splice organizer 21 according 
to the invention, the method aspects of the present invention will be 
readily understood. A method for organizing a plurality of optical fiber 
splices between first and second optical fiber groups 40A, 40B according 
to the invention includes the steps of guiding and securing respective 
slack portions of the first and second optical fiber groups from the first 
end of the base 30, along respective portions of the base adjacent the 
first and second sides thereof, into a plurality of overlying slack loops 
adjacent the second end of said base, and back to adjacent the first end 
of the base from respective first and second sides of the base. 
Accordingly, overlying respective slack loops of the first and second 
optical fiber groups 40A, 40B are readily separable from each other. The 
optical fiber splices are then secured on a medial portion of the base 30 
adjacent the first end thereof. Preferably, the first and second optical 
fiber groups 40A, 40B are secured to the base in laterally spaced apart 
relation prior to splicing. 
Another method aspect according to the present invention for splicing first 
and second optical fiber ribbon groups includes the steps of breaking out 
predetermined individual optical fibers from predetermined optical fiber 
ribbons and splicing the thus broken out predetermined individual optical 
fibers. In addition, the remaining optical fibers in the first and second 
optical fiber ribbon groups are also spliced. This method of separating 
out individual optical fibers from optical fiber ribbons is advantageously 
combined with the method for organizing first and second groups of optical 
fibers to provide ready separability. 
Many modifications and other embodiments of the invention will come to the 
mind of one skilled in the art having the benefit of the teachings 
presented in the foregoing descriptions and the associated drawings. 
Therefore, it is to be understood that the invention is not to be limited 
to the specific embodiments disclosed, and that modifications and 
embodiments are intended to be included within the scope of the appended 
claims.