CA2160474A1

CA2160474A1 - Fiber optic splice closure and associated methods

Info

Publication number: CA2160474A1
Application number: CA002160474A
Authority: CA
Inventors: Daniel Francois Daems; John Randolph Holman; Carney Preston Ii Claunch; Edward Jackson Wilcox
Original assignee: Individual
Current assignee: Raychem Corp
Priority date: 1993-04-19
Filing date: 1994-04-18
Publication date: 1994-10-27
Also published as: US5479553A; EP0736191A1; JPH08509303A; US5692299A; WO1994024599A1; ZA942606B; BR9406480A

Abstract

A splice closure including a frame having a partition wall to define front and rear access areas for the closure. The frame carries one or more splice trays on a first surface portion making the splices accessible from the front or first access area. A slack storage compartment is provided on the second surface portion.
The slack storage compartment includes one or more pairs of opposing sidewalls that define an access opening for the slack that is accessible from the rear access area. An extension member for the frame is disclosed for obtaining greater amounts of slack from the cable, such as for a taut sheath cable splice. A tandem longitudinal arrangement of splice trays is also disclosed and may be used for a taut sheath ring splice or for repairing a severed cable.

Description

~ WO 91/24599 2 1 ~ 0 4 7 ~ PCT/~S9 l/04232 FIBER OPIIC SPLICE CLOSURE AND
ASSOCLATED METHODS

Field of the Invention The invention relates to the field of fiber optic co~ niC~ti~ ns systems and e~lui~ t and, more particularly, to a splice closure for the storage and protection of fiber optic splices and ~c~i~teA slack.

Background of the Invçntion 0 Optical fiber co~ llllnic~tions systems are used extensively in the teleco.. ~ tions industry due to their large in~lmation carrying capacity, their virtually noise-free pelrol...Ance, and the long span ~lict~nces achievable with optical fibers before l~,g~nr.,.l;Qn and ~mplific~tion of the signal are l~uil~d. Practical limits on the lengths of optical fiber cables that can be m~nnf~l~tllred and inct~lle~l typically require 15 that several splice points be in~lnAr~l over the total cable route.
At each such splice location, all of the optical fibers are se~;~.,.tr~ from theother p~i~e cable cc,~ for sp~ ng and are, thus, more ~usc~l~Lible to damage.
In addition, the optical fibers at a splice point are h~n~ by a te~hni~ n who splices the fibers and stores the splices and ~csoc;~trcl slack in a ~-vt~cli~e splice closure. In almost all fiber optic ~.. ;~tions systems, it is critical that high quality and high reliability splices be obtained. Fusion and ~.ccl.Ani~l spli~-ing l~hni~lues and c~luiylll~llt have been developed that permit low loss, high quality, and durable splices to be obtained.
However, it may SC~ CS be n~cess~.~/ to remake or repair splices to achieve the desired splice quality.
There are many dirr~GI~ types of splice closures for l~rv~ecLing optical fiber splices wh~ç~ all of the fibers are spliced to c~ spondillg fibers in an ~ cent cable section. Typically, these splice closures include one or more splice organizing trays, on which the individual splices and the relatively short lengths of associated slack fibers are mounted. For example, the ~c~ignee of the present invention m~nllf~r.tures a conventional splice enclosure and splice organizer under the model cle~ign~tion FOSC

WO 9J/7 2 1 6 ~ 4 ~ 4 ! '~ PCrlU59JlOJ232 ~

100. Siecor Col~l~Lion of Hickory, North Carolina makes splice enclosures under the model decign~tions SC2, and SC4-6. Another splice enclosure is shown in UK Patent Application No. 2,150,313A ~ccignf ~1 to ~I,r.,. ,".--1 Line Products of Cleveland, Ohio.
Another c~ on fiber optic c~ tion system application l~uil;llg 5 fiber splicing inc!urlss a main cable serving several drop cables at spaced apart ~ tion~
along the route of the main cable. Splices are l~uil~d at these drop points; however, not all of the fibers in the main cable are severed and spliced. Rather, only a relatively small number of fibers are typically spliced to the drop cable. The ~ g fibers, or express fibers, are desirably left llnflist~rbed. Accordingly, a large amount of slack is typically 0 associated with these express fibers. This slack may be in the form of a plurality of buffer tubes, each in turn con~ ing a plurality of fibers.
Fiber optic splice closures have been developed for plulccLing the splices bel~.een a main cable and a drop cable. Such closures typically have an in-line n~ nt of inco...;ng and c~ cables. In ~d~ such C1O~U1GS typically have a com~ cnL for storing the relatively large amount of slack express fibers. For eY~mrlf, U.S. Patent No. 4,805,979 to Bossard et al. entitl~d Fiber Op~ic Cable Splice Closure and ~igned to 3M, ~lisc!oses an in-line splice closure inclllrling two rigid half shells.
Unff llunately, the 3M splice closure is assembled by routing the slack buffer tubes in a cclll~ llellL rlr~lned by the lower rigid shell, and the splice organizer trays and cable end ~ttaçh~ are built upon the bottom shell. Thus, initial assembly is so.lh,~l.aL complicated and, mo~eover, the slack is f~ALI~C1Y limrult to reaccess once the closure is assembled as the bottom shell cannot be removed without subst~nti~llyfli~ hling the entire splice closure.
U.S. Patent No. 4,679,896 to Krafcik et al. entitled Optical Fiber Splice Organizer discloses a splice closure including a bottom slack storage tray positioned within a cylindrical housing. The slack stored in the tray may only be ~- cess~ after removing a series of stacked splice Ol~ ; f.l s from a pair of upwardly e~rtenfling threaded studs. Stated in other words, the access opening for the slack storage ~ray is covered by the stacked splice O~ and access to the slack l~Uil~s di~ ing the splice trays.
Somewhat similar to the Krafcik et al. splice closure is the closure ~lescrihe~l in U.S. Patent No. 4,428,645 to Korbelak et al. entitled Cable Accumulator.
The splice closure includes a hinged and removable splice c,lg~lizer and underlying wo s~l24sss ~ 1 ~ 0 4 7 4 PCT/U$94/04232 co~ cu lul~ nt or tray for slack cable. The splice vrganizer must be pivoted out of the way to gain access to the slack storage COI11lJCU llll~ opening.
Similar to such conventional splice closures, is splice closure model FOSC 100~D m~nuf~rtllred by Rayche.n, ~c~ign~oe of the present invention. The FOSC
100~D includes as an option, a slack storage compcul~llent that may be mounted underlying a series of pivotally secured splice vl~ 7ing trays. The access opening for the slack storage cvll~culn~e n~ is covered by the splice organizing trays; however, the splice trays may be pivoted upward to gain access to the slack. Thus, the splice trays must still be reposition~ to access the underlying slack.
0 There are other applications where conventional splice closures have ~i~nific~nt shvllcvllungs. For example, when a new drop point must be added to an existing or preinstalled main cable, a so-called "taut sheath" splice is desirable.
Unfollullatc;ly, convention~l splice closure, such as the 3M closure, may be too short to permit sufficiçnt slack fibers to be cA~osed from the cable. Similarly, for a taut sheath ring splice, wLc,~ both incoming and oulgoillg ffbers are spliced to a drop cable, a convention~l closure does not permit ~inillg sl~ffcient slack for splicing.
Another shc,llco...;l-g of conventional splice closures is that the usc of such closures is eYren~ive for a typical repair of a severed cable, since two splice closures must be used. In other words, in a conventional repair, a patch length of slack 20 cable is spliced to restore the damaged cable section and two splice closures are used to protect each of the splices to the patch cable ends.

Objects and Sllmm~ry of ~e Invention In view of the foregoing background, it is thelefole an object of the 25 present invention to provide a splice closure for secnring optical fiber splices and slack, while f~c-ilit~tinp initial access and re~rcess to either the slack or the splices without disturbing the other.
It is another object of the present invention to provide a splice closure and ~oci~ted mr.tho~ for f~cilit~ting splirin~ of a drop cable, for eY~mrle, to a fiber optic 30 cable that has already been in~t~lled, such as in a taut sheath fiber splice.It a further object of the present invention to provide a splice closure and ~c~i~A method for 1~ a fl~m~g~l fiber optic cable.

wo gla4S99 ~ ~ 6 ~ i 7 ~ I'CT/US9-1/01232 These and other objects, fealuf~s, and advantages of the present invention are provided by a splice closure inrlu-ling an elongate frame and paTtition wall means for defining opposing front and rear, or first and second, opposing access areas for splice ory,a~ means and slack storage means. In other words, the splice closure according to 5 the invention permits access to the splices and slack relative independent from one another, thereby farilitating initial assembly and l~access within the splice closure.
The wall partition means defines surface portions ~Yt~nrling longiturlin~lly ~Iw~n c,yyosing ends of the frame. Thus, the splice 0~ ;,;..g means is on the front or first surface portion so that the splices are acces~ible from a first access area, while the 0 slack storage means is on the second surface portion of the partition wall means and stores slack optical fibers so that the slack is ~rcessihle from the second access area. The slack storage means preferably includes one or more pairs of opposing spaced apart sidewalls depending from the wall partition rneans and defining a slack storage access opening for f~ilit~ting access to the slack optical fibers from the second access area In one embo1~ nl of the splice closure, the splice organizing means preferably inclt)des a plurality of splice trays, and mounting means for mounting the splice trays in a stack. More particularly, the ..~U~ means preferably inchldes means for pivotally ~ou~ g an end of each splice tray for pivotal move~el-~ bel~. cen a stored position, generally parallel with the wall partition me~ns, and a raised posi~ion~ f~ilit~ting 20 access to an und~ g splice tray.
Another embodiment of the splice closure according to the present invention includes a second plurality of splice trays, and second mounting means for mollnting the splice trays in a second stack longihl~1in~lly ~ re-l t the first stack on the wall partition means. The second ~ UI~ g means also preferably inf~lndes second means 25 for pivotally Illounling an end of each splice tray for pivotal mov~,~nt ~l~. ~n the sta~ed and raised ~osi~;ol-~. In other words, this tandem splice tray em~lim~o-nt preferably includes an elongate frame, and splice or~r~.;7;.-g means on the frame, and wL~ the splice c~ lg means preferably inc!udes a plurality of splice trays and first and second ..-o~ ;,-g means for ~loullling at least one of the splice trays in each of respective first 30 and second lonpitllrlin~lly ~dj~ce.nt position~ on the el-ng~te frame.
The tandem splice tray embodim~q~t may be useful for a nllmber of appli~tion~, such as for facilitating the repair of a severed cable. In addition, the embo lim~nt may have application in a taut sheath splice, and especially in a taut sheath ~ WO 94/24599 0 ~ 7 ~ ` PCT/US94m4232 ring splice, as more fully described below with respect to method aspects of the present invention.
Another feature of the splice closure accol~ing to the present invention is that the wall ~al LiLion means inr~ (les at least one guide opening thcl~,Lllluugh for routing 5 optical fibers bet~.~,el~ the first and second access areas. Moreover, the guide opening preferably opens ouLw~lly to an edge of the wall partition means to facilitate positioning of optical fibers through the guide opening without requiring severing of the optical fibers.
In one embo ~ F l~ of the invention, the wall partition means incllldçs a 10 pair of opposing spaced apart generally rect~ng~ r walls lying in a Cûlllll1011 plane and e,Ytrn~ing in a longinltlin~l direction. The space be~ ,en the two walls defines a longit l-lin~lly cyt~onr3ing guide opening for routing optical fibers between the first and second access areas.
In another çmborlimrnt~ the wall partition means is provided by a generally rect~ng~ r wall having at least one T-shaped opening therein. The T-shaped opening may be relatively large and located in a longinldin~lly central portion of the rect~n~ r wall, or a pair of relatively small T-shaped openings may be provided ~j~rent opposing end pulLiolls of the ~ r wall.
Another aspect of the present invention is that a lon~ l eYtçn~ion ....... h~.l may be cûi-nec~d to an end of the wall partition means to provide an extended length for the closure. The eYtçn~ length may be rl~sir~hle in certain a~plica~iolls, such as a taut sheath cable splice, for eY~mple, as ~lescribe~l more fully below according to a method aspect of the invention. In one embo lim.o.nt, the eY-trn~ible m~mber may be provided by a rect~ng~ r wall or plate co~lnc~t~ in end-to-end relation to the elo~g~te 25 frame.
The splice closure according to the invention also preferably includes a housing ~u~ unding the frame, the splice Ul~;alliL~ means, and the slack storage means.
In one embod;.--f -l, such as for strict en~ir~n.-~Fnt~l se~ling, the housing may be a tubular metal shell with a heat recoverable m~teri~ luundillg the tubular shell. The 30 tubular shell may be provided by two lorgiturlin~lly cYIr.i-~il-g section~, each having a semicircular cross-sectinn~l shape. The tubular shell may also have tapered end portions defining a frusLoconical shape for sealing the ends of the housing where the relatively smaller rli~m.o.tr.r cables enter. To further enh~nce sealing of the housing ends, a pair of WO 9~/24599 ~ 7 4 ~ ; PCT/US9 1/0 ~232 elongate bodies are preferably positioned extending longit~ in~lly outward from res~f~ e ends of the frame to engage respective ends of the heat recoverable material housing.
Another aspect of the invention provides a tubular shell including first and 5 second lo~ ly eYt~n~ling se~tion~- Accordingly, an end portion of the first section is slidably posi*oneA within an end portion of the second section. Thus, the length of the housing may be readily ~rljnste~ in the field by the technician to ~cco.-...-~l~te the frame length and an extension ..,....1~1, as desired. In ~rlr1ition, the heat recoverable material is available relatively long lengths and may be r~adily cut to leng~.
0 In another embo~limPnt of the invention, such as for aerial applications where strict environment~l sealing is not required, the housing preferably includes first and second longiturlin~lly eYtenlling plastic panels. The panels are preferably joined together by an integrally lded lengthwise c~ 1~ nrl;ng hinge.
The splice closure accol~ing to the present invention is preferably used in an in-line configuration. Accor~lingly, the splice closure preferably includes cable securing means carried by c~posing end portions of the frame for securing respective fiber optic cables to the frame in the in-line cQnfi~ iol~
One methorl aspect of the present invention is for making a taut sheath fiber optic cable splice to one or more optical fibers in a cable of the type having an outer jacket and plurality of buffer tubes co~ ;ni.~g optical fibers. More particularly, the buffer tubes are ~rr~ngf~ around a central ~up~ g .~.f ~lr - in an oscill~ting helical lay pattern having a preA- -t~ ...;nP.1 period.
The method includes providing a splice closure including an elongate frame and splice o~ -g means mounted thereon for holrling one or more optical fiber 25 splices, the frame having a preAelel...;nc~l length as least as great as the period of the osc ~ ting helical lay pattern of the cable. The jacket is removed from the pl`edf~ t~ eA
longit~ in~l portion of the cable co~ ;ng to the period of the os~ tinpi helical lay pattern of an underlying ~ t - Il;--~d buffer tube to thereby ~ UC,f slack in the buffer tube. The cable is secured to the frame and the one or more fibers of the yl~et~ - ,nillcA
30 buffer tube are spliced to l~i~cc~i~/e fibers of another fiber op~ic cable. The splices are secured within the splice organizer means and the housing is placed surrounding the splice c,l~ means and the frame.

~I WO 94/24S99 2 1 ~ 0 4 7 4 . pcTlus9~m4232 For a typical taut sheath splice, the splice closure including the extension member may be used to provide the ~ddition~l length l~u~ed to obtain sufficient slack.
For a taut sheath ring splice, the tandem splice tray splice closure may be advantageously used.
Another m~thod aspect according to the invention is dir~Led to lGyaifillg a severed portion of a fiber optic cable. The method in~hl~les the steps of providing a splice closure in~ rling an elon~te frame, and splice ol~ g means on the frame for securing splices bet~ e" predetermined optical fibers. The splice organizing means in~ fl.o.s a plurality of splice trays and first and second mounting means for mounting at least one of the splice trays in each of l.,i,~Li~/e first and second longitll.lin~lly adjacent positions on the elong~te frame. In other words, the tandem splice tray splice closure is provided. Other steps include: securing l~ syec~i~e first and second ends of the fiber optic cable to lesye~ Li~/e opposing ends of the elongate frame of the splice closure, making first and second splices ~l~..en a patch optical fiber and l~s~c~ e first and second ends of each severed optical fiber, and positiQning the first and second splices in splice trays at l~;,~;Li~e first and second lon~ l;n~lly ~lj~ce-nt position~ on the elong~t~
frame. Accordingly, the tandem lon~;l.,.l;n~l arrangement of the splice trays ~l,nils Gl)~ .ing slack for 1~;~ ;ng each severed optical fiber with an intervening patch optical fiber. The splice closure also preferably includes a hollsing ~ullollnding the frame and the two stacks of splice trays.

P~rief Description of the Drawin~.~
~;IG. 1 is an eYplo~ e~ e view of an embodiment of the splice closure acculdillg to the invention.
FIG. 2 is a rear p~ view of the emb~im~nt of the splice closure as shown in FIG. 1 with the holl~ing l~,llw~cd for clarity.
FIG. 3 is an enlarged plan view of the embo~lh~ nl of the splice closure as shown in PIG. 1 with the housing removed for clarity.
FIG. 4 is a f~g.. -lS.. ~ front view of another e.l,b~l;.. -ent of the splice 30 closure ac.;o~ lg to the present invention.
~ ;IG. S is a greatly enlarged plan view of a portion of the embo~liment of the splice closure shown in ~;IG. 4 with the housing removed for clarity.

wo g~/24s99 2 16 0 4 '7 9; PCT/USg4m4232 FIG. 6 is a cross-gection~l view of the housing of the splice closure taken along lines 6-6 as shown in FIG. 4.
FIG. 7 is a cross-section~l view of the housing of the splice closure as in FIG. 6 shown in an open position to f~r.iljt:lte s-~mbly.
FIG. g is a front view of yet another embo limrnt of the splice closure according to the invention with the housing removed and without the optical fibers or splices being shown for clarity.
FIG. 9 is front view of another emb~liment of the splice closure accc,l~ling to the invention illu~lla~ g a tandem a~n~rmrnt of splice trays, and with the 0 housing removed for clarity.
FIG. 10 is a pCl~p-~ L ve view of another embodiment of a housing according to the invention.

n~t~iled Descri~tion of dle rlefe-l~d Embodiments The present invention will now be described more fully hereinafter with rer l~nce to the accompanying drawings, in which plefc.l~d embof~ el~t~ of the invention are shown. This invention may, however, be emhoAieA in many liLrc~nt forms and should not be col,sLlued as limited to the embo~ t~ set forth herein.
Rather, applicants provide these e ...h~~ . so that this disclosure will be thorough and 20 comrlete, and will fully convey the scope of the invention to those skilled in the art. Like nu~b~l~ are used in ~ltPrn~tf elllb~~ to clesi~e similar c~
Referring first to PIGS. 1-3, a first elllb~l;..~ of the splice closure 15 ac~l~lillg to the invention is eYrl~in~l The splice closure 15 is for secllring splices 19 ~L~ .,.I individual optical fibers 20 ~ t~ ~l;n~ ~om one or more fiber optic bufer tubes 25 23 of one or more fiber optic cables 22.
The splice closure 15 inrl~des an elongate frame 16 having opposing ends. More particularly, in the illn~tr~qtr-l embo-limPnt, the frame 16 incllldes wall partition means provided by a pair of spaced apart genrr~lly rect~n~ r walls 17 lying in a co..~...on plane and eytrnrling in a longitl~rlin~l dil~lion. The wall partition means 30 provided by the spaced apart walls 17 defines OppOSillg first and second surface portions çYten~iing lorlgit~tlin~lly bel~ n opl)o~ing ends of the frame 16. These opposing first and second surface portions, in tu~n, define l~ e O~yO~ g first and second, or front and rear, access areas as highlightetl in FIG. 3.

2 ~ 6 ~ 4 7 4 J PCT/US94104232 Splice org~ni7ing means is positioned on the first or front surface portion of the pair of walls 17 for securing splices 19 ~l~.~ e n predelcln~ined optical fibers 20 so that the splices are ~eces~ible from the first access area. As shown in the illustrated embo limtont, the splice org~ni7ing means includes a plurality of splice trays 25, and 5 mollnting means for l~oun~ing the splice trays in a stack. The ll-OU~ g means preferably includes means for pivotally .~o,~ g an end of each splice tray 25 for pivotal movement between a stored position, generally parallel with the pair of walls 17, and a raised position, f~cilit~ting access to an underlying splice tray as also shown best in FIG. 3.
As shown in the illustrated emb~imf nt, the pivotal mounting means 0 incl~ldes a bracket 26 having a series of openings therein receiving hinge pins 27 for pivotally mounting the splice trays 25 to the frame 16. Other pivotal mounting arr~n~c ..~,nl~ will be readily ~I,l~iated by those skilled in the art.
The bracket 26 is integrally formed with the pair of walls 17 forming the wall partition means. Accordingly, the frame 16 incl~des a second integrally formed 5 bracket 28 at an UpposilG end of the frame so that the frame may be formed from a single sheet of metal.
Slack storage means is provided on the second or rear surface portion of the pair of walls 17 for storing slack 30 conli.;.-rA within buffer tubes as shown in the illl.~l.~tr~ cmbo l;.--f-Qt. Accordingly, the slack 30 is acces~ible from the second access 20 area, and may be initially ~rcessfYl and r~cces~fA without ~ nc~e~ ;ly disturbing the splice trays 25. As would be readily understood by those skilled in the art, the slack 30 may be in the form of buffer tubes, individual fibers, or LlallSl)Oll tubes, for example.
The slack storage means preferably includes one or more pairs of opposing spaced apart sidewalls 32a, 32b rk,~ g from the pair of walls 17 which 25 provide the wall partition means. In the illu~ ted embo li.... -t, the sidewalls include ec~i-~e inwardly facing tabs 34a, 34b to further secure the slack 30 in place. In addition, the sidewalls 32a, 32b have an arcuate shape cc,llGi,l,onding to the circular cross-section shape of the hou~ing 40 described in greater detail below. The free ends of the sidewalls 32a, 32b and their lc~ecLi~re tabs 34a, 34b thus define a slack storage 30 access opening for f~ilit~ting access to the slack optical fibers from the second or rear aceess area (FIGS. 2 and 3).
Referring now more particularly to FIG. 2, the pair of walls 17 which providethe wall partition means also define a lon~itll~lin~lly e~ct~n-ling guide opening 37 WO 94/24599 21~ 0 4 7 4 PCT/llS94m4232 ~

for routing optical fibers bel~. ~n the first and second access areas. The guide opening 37 also opens outwardly to an end edgë of the wall partition means to facilitatepositioning of optical fibers through~the guide opening without requiring severing of the ophcal fibers.
Referring now more particularly to FIG. 1, the splice closure also preferably inr~ludes a housing 40 ~ull~undillg the frame 16, the splice organizer means, and the slack storage means. As shown in the illustrated emb~imtont, the housing 40 includes a tubular shell having first and second halves 41a, 41b and a heat recoverable material sheet 42 surrounding the tubular shell. As would be readily nn-lerstood by those skilled in the art, the housing 40 is preferably of the conventif n~l type used in splicing of copper cables collll~ollly used in the telephone industry.
The shell halves 41a, 41b each preferably have a semicircular cross-section~l shape, and a plurality of tapered end portions for dçfining a frllctocor~ l shape for the housing ends when the heat recoverable m~tPri~l sheet 42 is heated and draws down upon the shell. In ~ liti~ll, each shell half 41a, 41b also preferably includes a series of lon~ihl~lin~11y spaced apart tabs 43 offset on c,~osing shell edges to llle.eby form a hinge-like joint.
The heat recoverable m~t~ri~l sheet 42 preferably includes an adhesive flap portion 45 for sealing the lon~ l;n~l seam ~I~.c~,n the o~posing beaded edges 47 of the sheet. In addition, a clip 46 is preferably used to secure the o~,posing beaded edges 47 of the heat recoverable m~tori~l sheet 42.
To further assist in sealing the end portions of the housing 40, the splice closure preferably also includes a pair of elongate tubular bodies 48 extending lon~itll-lin~lly Ou~ d from l~s~ccli~e ends of the frame 16. The tubular bodies are secured to ~ /e b, ~ .t~ 26, 28 at each end of the ~frame 16. The elongate tubular bodies 48 increase the ...;.~ rli~m~oter to which the heat recoverable m~t~ri~l of the holl~ing 40 must shrink to seal the ends of the housing to the çntering cables 22.
The elong~te tubular bodies 48 also cooperate with l~c~ e r~
such as tie wraps 49, to provide means for se~nring the fiber optic cables 22 to the frame 30 16 in an in-line confignration. To further reduce the lik~lihood of water migT~tic n into the interior of the splice closure 15, the ends of the cables 22 may be sealed by a water blocking colll~ul~d and heat shrink tubular cover 50 as would be readily understood by those skilled in the art.

~ WO 9~1/2~599 21 6 ~4 74 ; PCT/US94/04232 Referring now to FIGS. 4-7 a second emWime.nt of the splice closure 60 according to the invention is explained. This embodiment of the splice closure 60 is particularly well suited for an aerial inct~ tion as shown, wherein the splice closure is su~polled from an ov~,ll.ead messenger strand 61. To f~cilit~te underst~nding of this 5 embo-liment, like numbers are used where possible for like e!çm~ tc ~liccucsetl above with respect to the cmWimtont of the splice closure as shown in ~;IGS. 1-3.
The splice closure 60 incl~-(les an elongate frame 62 on which splice org~ni7.ing means pivotally secures a plurality of splice trays 25. The splice trays 25 hold splices 19 ~I~. een plGrlet~ optical fibers 20 from predet~lll)ined fiber optic o cables 22. The splice closure 60 also includes wall partition means provided by a generally rect~n~nl~r wall 63. The splice organizer means is on a first or front surface portion of the gençr~lly rect~ng~ r wall 63.
Slack storage means is on the second or back surface of the generally rect~n~ r wall 63 so that the slack 30 is a~cçccible from the second or rear access area 5 (FIG. 5). The slack storage means is provided by one or more pairs of opposingsidewalls, only one sidewall 34b being shown in the ill..~ ti~ embolim~-~t for clarity.
The sidewalls define a slack access opening for the splice closure 60.
A relatively large T-shaped guide opening 67 (FIG. 4~ is provided in a central or medial portion of the generally rect~ng~ r wall 62 so that slack 30 may be 20 readily poition~A within the slack storage means and routed ~l~,. ~n the first and second access areas of the splice closure 60. The T-shaped guide opening 67 preferably opens oul~dly to a bottom edge of the generally rectangular wall 63 as shown in the illustrated GLubo~l;...e~-t Accordingly, the e~ ,s buffer tubes 23 not being ~cesseA
may be readily position~d into the slack storage means willlOul l~ULling cutting of the 25 buffer tubes.
The frame 62 of the splice closure 60 is sll~pçn-i~l from the mP~sse~ng~r 61 by a pair of metal L-shaped m~o.mbers 65. An in~nl~tor, not shown, may be positioned bcl~.~,en each of the L-shaped ...r ...1~ i 6S and the frame 62 to electrically isolate the frame. In addition, proper ~lignment of the fiber optic cables 22 e.mering the 30 splice closure 60 is m~int~ined by stacked spacers blocks 66 as would be readily understood by those sl~lled in the art.
As shown in the ill~-cl-~lerl emboliment, the splice closure 60 is suited for splicing cables 22 in an in-line configuration. Accorllingly, the splice closure 60 WO 94/24599 216 ~ 4 7 4 ~ PCT/US9~/04232 , ~ ~

int lndt s means for securing the cables~ 22 ~n an in-line configuration. More parhcularly, the generally rect~ng~ r wall 63 ~n~iuries openings 68 ~ ent each end df fining stubs 69 for securing ends of the cable 22 thereto with a f~ctr.ner, such as a band clamp 70.
The housing 75 for the splice closure 60 as illu~LIalccl includes first and 5 second longit~ in~lly eYten-ling corrugated plastic panels 76, and an intf gr~lly molded lon~ lly ~ .~. ntling hinge po~ion 78 illt~l~;O.~.~f~;l;..g the plastic panels. The housing 7S includes generally rectangular end openings 79 which are secured around c~~ onding rectangularly shaped end caps 80 through which the cables 22 enter the splice closure. As shown in FIGS. 6 and 7, the plastic panels 76 are joined together at 0 their bottom edges by l~spe~ e projections 81 and cc,l.~sl,onding openings 82.Referring now to FIG. 8, another aspect of the present invention is eYpl~ineA. In certain applir~tion~ access to a relatively long length of optical fibers 20 cont~inf~l within the fiber optic cable 22 may be required. For example, it may be df~ hle to add a drop cable to a main cable that is already in~t~llrA, that is, to make a taut 5 sheath splice. Accordingly, the ~ .PI-~ of the splice closure 90 as illus~ ,d may thus be used to mount and protect the splices and the e~posed relatively long portion of the cable. To ~çco.. cd~l~; such al~ui~ nt, a 1Qn~ 1;n~1 eYtrn~iorl .. ~ .. 1.~;.. 95 may be col~necl~ to an end of the frame 91. In the illustrated emkPlimrnt, the frame 91 incl~ldes a genf .r~lly rect~n~ r wall 92.
The eYtf n~ion l~f .~ 95 and the gcnf r~lly rect~n~ r wall 92 may have o~ pil~g ends as ill"~ t~ ~1 and r~ ning means for secnring the ends together with an adjustable degree of overlap to provide a pre~lelf - Ill;nrd length for the splice closure 90.
As shown in the illn~tr~A embo1im~ t, the f~tening means includes a pair of slotted openings 97 in each ~,Ytf n~ion 1~ 95 and the generally rect~nglll~r wall 92, and a pair of bolts 98 eYten-ling through the l~c~ re oFening~ As would be readily llntl~rstood by those skilled in the art, other shapes of lc-ng;l~l.l;n~l eYt~n~ion mtomher may also be provided, and other auael~ t arran~ n nt~ for the extension ~ .llbel arecol It I .p!~t~A by the invention.
FIG. 8 also illustrates anoth.,l feature of the invention, that is, a pair of relatively small T-shaped openings 99 provided in the generally rect~n~ r wall 92 for f~ilit~ting routing of fibers be~ the front and rear access areas of the splice closure 90. As illustrated, the T-shaped openings 99 open ouLwal~lly to an upper edge of the gçn.o.r~lly rect~ng~ r wall 92.

~ WO 94/24599 2 1~ ~ 4 7 4 i~ Pt CT/US94/04232 Referring now to FIG. 9, another emb~lim~ nt of a splice closure 110 according to the invention is ill~lstr~ted This embodiment of the splice closure 110 includes a m~rri~ge of the coll")onellt~ of two splice closures 15 as illustrated in FIGS.
1-3. Thus, where possible, like l ÇelGI-ce null~ are used in FIG. 9 and the following 5 desc~ ion for ease of underst~n-ling More particularly, as shown in the central portion of FIG. 9, the r~ ec~i~re frames 16 of two splice closures are joined in end-to-end relation bypositioning fasteners, not shown, through each protruding tab 111 and cullG;,~ollding opening, not shown, in the frames. As would be readily understood by those skilled in o the art, other secllring arr~ng.. l~ may also be used.
The illu~ ted embodiment of the splice closure 110 includes first and second llloull~ing means for l-~oulllillg the plurality of splice trays 25 in respective first and second long~hlrlin~lly p~ cent stacks on the joined together frames 16. As ~ c~ e-3 above with respect to ~;IGS. 1-3, each of the first and second .llolln~lg means preferably 5 include means for pivotally l~-o~Jn~.ng an end of each splice tray 25 for pivotal mo~,e~nt b~l~.eell a stored posihion, generally parallel with the frame, and a raised position, f~ ilit~ting access to an und~ ,lyi~g splice tray.
The entry of optical fibers 20 into each splice tray 25 in l~s~c~i~i /e stacks is i...,.~r~ tP.ly prlj~ent rei,~cc~i.~e ends of the splice closure 110. Accordingly, more 20 efficient usage of the slack is achieved. The other attendant fca,lul.s and benefits inr,lurlin~ splice access from the front access and area, and slack access from the rear access area are also present in the ~llbo~l;. . .- .~l illus~ .~cd in FIG. 9.
The splice closure 110 with the tandem sets of splice trays 25 may have a wide n-~ of applicaLions. In particular, the splice closure 1lO may be readily used to 25 repair a severed cable while .~u~;ng the use of only one splice closure 110 rather than two as in the prior art. This method aspect of the invention is rlisc~lsse~l further below.
Another application for the splice closure is a taut sheath ring splice. Yet another application for the splice closure 110 may include achieving a higher capacity for splices within the closure. These and yet other applications for the splice closure 110 will be 30 readily a~pl~ia~d by those skilled in the ar~
Another aspect of the emho l;.,~r~ of the splice closures 90 and 110 as shown in FIGS. 8 and 9, n,sp~li~rely, is that each relatively long assembly may be readily ~ulluunded by a single housing of sllffirient length. A housing 75 of the type as W O 9~/24599 ~ 4 ~ PCTrUS94104232 shown in FIGS. 4, 6 and 7 may be u~l. such as for an aerial applir~tic-n where strict en~uu~ ` .ntz~l sealing is not l~u~ed. ~ltrrn~tively, a heat recoverable housing 40 of the type shown in FIG. 1 may be used for the emboAim~nt~ str~t~-A in FIGS. 8 and 9. In addition, another v~ri~tion of an e~ten~ihle heat recoverable housing 120 is shown in FIG. 10.
As shown in FIG. 10, the housing 120 includes first and second lon it~lAin~lly extenAing sections 121, wL.~ an end portion of the first section is slidably positioned with an end portion of the second section. Thus, the length of the housing 120 may be seleclcA by adjusting the amount of overlap of the ends of the o lonEit~lAin~lly e-Yt~-nAing section~ 121, and cutting the heat recoverable m~teri~l sheet 42 and the securing clip 46 to a cc,,,~;,ponLIlg length. ~lthollgh not shown for clarity, each of the shell section~ 121 may, in turn, include a pair of longitl~Ain~l section~ as shown in FIG. 1.
One m-o.thoA aspect of the present invention is for making a taut sheath splice to one or more optical fibers in a cable of the type having an outer jacket and plurality of buffer tubes co~ h~h~E optical fibers. ~ore particularly, as would be readily unde.~ od by those skilled in the art, the buffer tubes are arranged around a central ~up~~ g . . ~ .nbe~ in an oscill~ting helical lay pattern having a ~ Acte- . . ~ eA perioA In other words, the helical lay pattern ,c~ses at regular intervals along the cable.
The n-ethoA incl~lAes providing a splice closure incl~lAing an elongate frame and splice ol~i~n;~ g means ~unled thereon for holAinE one or more optical fiber splices, the frame having a predet~ ineA length as least as great as the period of the oscill~ting helical lay pattern of the cable. The jacket is removed from a preAetormineA
longit---lin~l portion of the cable coll~ g to the period of the oscill~ting helical lay 25 pattern of an underlying preAetermineA buffer tube to Llh.~,by produce slack in the t~ ;neA buffer tube. The ylcd~t~ ,..h~r~A long;~ l portion of the cable is secured to the frame. Splicing of one or more of the fibers of the ~l~Ae~ h-~ buffer tube to i./e one or more fibers of another fiber optic cable is ye.Ç~",ed, and the splices are secured within the splice o,E,~r means.
The taut sheath splice is also preferably yl~lec~d by secll~ing a housing of the splice closure around the frame and the splice organizer means. In addition, the step of providing the elongate frame of pred~,tc .~ -ed length preferably includes the step of adding an eYten~ion l~f ~ to a first longinl-lin~lly eYten-ling portion of the frarne on ~ WO 94/24599 216 ~ ~ ~ 4 PCT/US94/04232 which the splice organizer means is . . ~. ..~ as described above. Alternatively, the step of providing the splice closure may include providing the tandem splice tray embo~1im~qnt of the splice closure as also descr1be~1 above.
Another method aspect according to the invention is di.~led to rep~iring a 5 severed portion of a fiber optic cable. The method in~ es the steps of providing a splice closure in~ ling an elon~te frame, and splice G~ izing means on the frame for securing splices l~,.e~ d~tc,.l-ined optical fibers, the splice org~ni7in~ meansi~clu~1; g a plurality of splice trays and first and second ulountil g means for ll-ou..ling at least one of the splice trays in each of l.,s~;~ e first and second lollgihlrlin~lly adjacent 10 po~;l;on~ on the .olong~t.o frame. In other words, the tandem splice tray splice closure is provided.
The other steps of the repair method include securing respective first and second ends of the fiber optic cable to l~ re u~po~ing ends of the elol-g~te frame of the splice closure, m~king first and second splices ~t~.een a patch optical fiber and 6 l~ re first and second cnds of each severed optical fiber, and ~os;l;--l.;.-g the first and second splices in splice trays at lespc.,live first and second longihlrlin~lly ~ cent positi~ nc on the elol-g7~le frame. Accordingly, the tandem longitll~in~ ng~om~ nt of the splice trays l,~.ll ils obtaining slack for rep~iring each severed op~cal fiber with an in~l~ning patch optical fiber.
Many .. -~~ l;ol~c and other c .. I.l;,.~,.. t~: of the invention will come to the _ind of one skilled in the art having the benefit of the te~hingc presented in ~e rc,l~,~,uing dGselip~ions and the ~c~oci~t~ drawings. Th~,l.,r.,lG, it is to be llnderctood that the invention is not to bc limited to the ~illc em~l;n~ d;~loser1, and that ...nfl;~l~s.l;nn~ and c-l,bo l; -~ ,l~ are ;.-~ ~ to be includ~d within thc scope of the 25 appended claims.

Claims

THAT WHICH IS CLAIMED IS:

1. A fiber optic splice closure for one or more fiber optic cables of the type having one or more optical fibers, said splice closure comprising:
an elongate frame having opposing ends, said frame including partition wall means for defining opposing first and second surface portions extending longitudinally between opposing ends of said frame, said opposing first and second surface portions defining respective opposing first and second access areas;
splice organizing means on the first surface portion of said partition wall means for securing splices between predetermined optical fibers so that the splices are accessible from the first access area; and slack storage means on the second surface portion of said partition wall means for storing slack optical fibers so that the slack optical fibers are accessible from the second access area.

2. A splice closure according to Claim 1 wherein said slack storage means comprises a pair of opposing spaced apart sidewalls depending from said wall partition means and defining a slack storage access opening for facilitating access to the slack optical fibers from the second access area.

3. A splice closure according to Claim 1 wherein said splice organizing means comprises a plurality of splice trays, and mounting means for mounting said splice trays in a stack, and wherein said mounting means includes means forpivotally mounting an end of each splice tray for pivotal movement between a stored position generally parallel with said wall partition means and a raised position facilitating access to an underlying splice tray.

4. A splice closure according to Claim 3 further comprising a second plurality of splice trays, and second mounting means for mounting said splice trays in a second stack longitudinally adjacent the first stack on said wall partition means, and wherein said second mounting means includes second means for pivotally mounting an end of each splice tray for pivotal movement between a stored position generally parallel with said wall partition means and a raised position facilitating access to an underlying splice tray.

5. A splice closure according to Claim 1 wherein said wall partition means includes at least one guide opening therethrough for routing optical fibers between said first and second access areas.

6. A splice closure according to Claim 5 wherein said at least one guide opening is open outwardly to an edge of said wall partition means to facilitate positioning of optical fibers through said at least one guide opening without requiring severing of the optical fibers.

7. A splice closure according to Claim 1 wherein said wall partition means comprises a pair of opposing spaced apart generally rectangular walls lying in a common plane and extending in a longitudinal direction thereby defining a longitudinally extending guide opening for routing optical fibers between said first and second access areas.

8. A splice closure according to Claim 1 wherein said wall partition means comprises a generally rectangular wall having at least one T-shaped opening therein and defining at least one guide opening for routing optical fibers between said first and second access areas.

9. A splice closure according to Claim 1 further comprising a longitudinal extension member connected to an end of said wall partition means.

10. A splice closure according to Claim 1 further comprising a housing surrounding said frame, said splice organizer means, and said slack storage means.

11. A splice closure according to Claim 10 wherein said housing comprises a tubular shell and a heat recoverable material surrounding said tubular shell.

12. A splice closure according to Claim 11 wherein said tubular shell comprises first and second longitudinally extending sections, and wherein an end portion of the first section is slidably positioned within an end portion of the second section.

13. A splice closure according to Claim 11 further comprising a pair of elongate bodies extending longitudinally outward from respective ends of said frame and engaging respective ends of said heat recoverable housing to enhance sealing of same.

14. A splice closure according to Claim 10 wherein said housing comprises first and second longitudinally extending plastic panels, and an integrally molded lengthwise extending hinge portion interconnecting said first and second plastic panels.

15. A splice closure according to Claim 1 further comprising cable securing means carried by opposing end portions of said frame for securing respective fiber optic cables to said frame in an in-line configuration.

16. A fiber optic splice closure for one or more fiber optic cables of the type having one or more optical fibers, said splice closure comprising:
an elongate frame having opposing ends, said frame including partition wall means for defining opposing first and second surface portions extending longitudinally between opposing ends of said frame, said opposing first and second surface portions defining respective opposing first and second access areas;
splice organizing means on the first surface portion of said partition wall means for securing splices between predetermined optical fibers so that the splices are accessible from the first access area, said splice organizing means comprising a plurality of splice trays and mounting means for mounting said splice trays in a stack, said mounting means including means for pivotally mounting an end of each splice tray for pivotal movement between a stored position generally parallel with said wall partition means and a raised position facilitating access to an underlying splice tray; and slack storage means on the second surface portion of said partition wall means for storing slack optical fibers so that the slack optical fibers are accessible from the second access area, said slack storage means comprising a pair of opposing spaced apart sidewalls depending from said wall partition means and defining a slack storage access opening for facilitating access to the slack optical fibers from the second access area.

17. A splice closure according to Claim 16 wherein said splice organizing means further comprises a second plurality of splice trays, and second mounting means for mounting said splice trays in a second stack longitudinally adjacent the first stack on said wall partition means, and wherein said second mounting means includes second means for pivotally mounting an end of each splice tray for pivotal movement between a stored position generally parallel with said wall partition means and a raised position facilitating access to an underlying splice tray.

18. A splice closure according to Claim 16 wherein said wall partition means includes at least one guide opening therethrough for routing optical fibers between said first and second access areas.

19. A splice closure according to Claim 18 wherein said at least one guide opening is open outwardly to an edge of said wall partition means to facilitate positioning of optical fibers through said at least one guide opening without requiring severing of the optical fibers.

20. A splice closure according to Claim 16 wherein said wall partition means comprises a pair of opposing spaced apart generally rectangular walls extending in a common plane and in a longitudinal direction thereby defining a longitudinallyextending guide opening for routing optical fibers between said first and second access areas.

21. A splice closure according to Claim 16 wherein said wall partition means comprises a generally rectangular wall having at least one T-shaped opening therein and defining at least one guide opening for routing optical fibers between said first and second access areas.

22. A splice closure according to Claim 16 further comprising a longitudinal extension member connected to an end of said wall partition means.

23. A splice closure according to Claim 16 further comprising a housing surrounding said frame, said splice organizer means, and said slack storage means.

24. A splice closure according to Claim 23 wherein said housing comprises a tubular shell and a heat recoverable material surrounding said tubular shell.

25. A splice closure according to Claim 24 wherein said tubular shell comprises first and second longitudinally extending sections, and wherein an end portion of the first section is slidably positioned within an end portion of the second section.

26. A splice closure according to Claim 24 further comprising a pair of elongate bodies extending longitudinally outward from respective ends of said frame and engaging respective ends of said heat recoverable housing to enhance sealing of same.

27. A splice closure according to Claim 23 wherein said housing comprises first and second longitudinally extending plastic panels, and an integrally molded lengthwise extending hinge portion interconnecting said first and second plastic panels.

28. A splice closure according to Claim 16 further comprising cable securing means carried by opposing end portions of said frame for securing respective fiber optic cables to said frame in an in-line configuration.

29. A fiber optic splice closure for one or more fiber optic cables of the type having one or more optical fibers, said splice closure comprising:
an elongate frame; and splice organizing means on said frame for securing splices between predetermined optical fibers, said splice organizing means comprising a plurality of splice trays and first and second mounting means for mounting said plurality of splice trays in respective first and second longitudinally adjacent stacks on said frame, each of said first and second mounting means including means for pivotally mounting an end of each splice tray for pivotal movement between a stored position generally parallel with said frame and a raised position facilitating access to an underlying splice tray.

30. A splice closure according to Claim 29 wherein said elongate frame includes partition wall means for defining opposing first and second surface portions extending longitudinally between opposing ends of said frame, wherein said opposing first and second surface portions define respective opposing first and second access areas, and wherein said splice organizing means is on the first surface portion of said wall partition means.

31. A splice closure according to Claim 30 further comprising slack storage means on the second surface portion of said wall partition means for storing slack optical fibers, and wherein said slack storage means comprises a pair of opposing spaced apart sidewalls depending from said partition wall means and defining a slack storage access opening for facilitating access to the slack optical fibers from the second access area.

32. A splice closure according to Claim 29 further comprising a housing surrounding said frame, and said splice organizer means.

33. A splice closure according to Claim 32 wherein said housing comprises a tubular shell and a heat recoverable material surrounding said tubular shell.

34. A splice closure according to Claim 33 wherein said tubular shell comprises first and second longitudinally extending sections, and wherein an end portion of the first section is slidably positioned within an end portion of the second section.

35. A splice closure according to Claim 33 further comprising a pair of elongate bodies extending longitudinally outward from respective ends of said frame and engaging respective ends of said heat recoverable housing to enhance sealing of same.

36. A splice closure according to Claim 32 wherein said housing comprises first and second longitudinally extending plastic panels, and an integrally molded lengthwise extending hinge portion interconnecting said first and second plastic panels.

37. A splice closure according to Claim 29 further comprising cable securing means carried by opposing end portions of said frame for securing respective fiber optic cables to said frame in an in-line configuration.

38. A fiber optic splice closure for one or more fiber optic cables of the type having one or more optical fibers, said splice closure comprising:
an elongate frame; and splice organizing means on said frame for securing splices between predetermined optical fibers, said splice organizing means comprising a plurality of splice trays and first and second mounting means for mounting at least one of said splice trays in each of respective first and second longitudinally adjacent positions on said elongate frame.

39. A splice closure according to Claim 38 wherein said elongate frame includes partition wall means for defining opposing first and second surface portions extending longitudinally between opposing ends of said frame, wherein said opposing first and second surface portions define respective opposing first and second access areas, and wherein said splice organizing means is on the first surface portion of said wall partition means.

40. A splice closure according to Claim 39 further comprising slack storage means on the second surface portion of said wall partition means for storing slack optical fibers, and wherein said slack storage means comprises a pair of opposing spaced apart sidewalls depending from said partition wall means and defining a slack storage access opening for facilitating access to the slack optical fibers from the second access area.

41. A splice closure according to Claim 38 further comprising a housing surrounding said frame, and said splice organizer means.

42. A splice closure according to Claim 41 wherein said housing comprises a tubular shell and a heat recoverable material surrounding said tubular shell.

43. A splice closure according to Claim 42 wherein said tubular shell comprises first and second longitudinally extending sections, and wherein an end portion of the first section is slidably positioned within an end portion of the second section.

44. A splice closure according to Claim 42 further comprising a pair of elongate bodies extending longitudinally outward from respective ends of said frame and engaging respective ends of said heat recoverable housing to enhance sealing of same.

45. A splice closure according to Claim 41 wherein said housing comprises first and second longitudinally extending plastic panels, and an integrally molded lengthwise extending hinge portion interconnecting said first and second plastic panels.

46. A splice closure according to Claim 38 further comprising cable securing means carried by opposing end portions of said frame for securing respective fiber optic cables to said frame in an in-line configuration.

47. A fiber optic splice closure for fiber optic cables of the type having one or more optical fibers, said splice closure comprising:
an elongate frame;
splice organizer means on said frame for securing optical fiber splices between respective fiber optic cables;
a longitudinal extension member connected to an end of said frame;
cable securing means carried by opposing end portions of said frame and said extension member for securing a fiber optic cable in an in-line configuration; and a housing extending longitudinally along said frame and said extension member said housing surrounding said frame, said extension member and said splice organizer means.

48. A splice closure according to Claim 47 wherein said housing comprises a tubular shell and a heat recoverable material surrounding said tubular shell.

49. A splice closure according to Claim 48 wherein said tubular shell comprises first and second longitudinally extending sections, and wherein an end portion of the first section is slidably positioned within an end portion of the second section.

50. A splice closure according to Claim 48 further comprising a pair of elongate bodies extending longitudinally outward from respective ends of said frame and said extension member and engaging respective ends of said heat recoverable housing to enhance sealing of same.

51. A splice closure according to Claim 47 wherein said housing comprises first and second longitudinally extending plastic panels, and an integrally molded lengthwise extending hinge portion interconnecting said first and second plastic panels.

52. A splice closure according to Claim 47 wherein said elongate frame includes partition wall means for defining opposing first and second surface portions extending longitudinally between opposing ends of said frame, wherein said opposing first and second surface portions define respective opposing first and second access areas, and wherein said splice organizing means is on the first surface portion of said wall partition means.

53. A splice closure according to Claim 52 wherein said splice organizing means comprises a plurality of splice trays and mounting means for mounting said splice trays in a stack on the first surface portion of said partition wall means, and wherein said mounting means includes means for pivotally mounting an end of eachsplice tray for pivotal movement between a stored position generally parallel with said wall partition means and a raised position facilitating access to an underlying splice tray.

54. A splice closure according to Claim 52 further comprising slack storage means on the second surface portion of said wall partition means for storing slack optical fibers, and wherein said slack storage means comprises a pair of opposing spaced apart sidewalls depending from said partition wall means and defining a slack storage access opening for facilitating access to the slack optical fibers from the second access area.

55. A method for making a taut sheath optical fiber splice to a fiber optic cable of the type having an outer jacket and plurality of buffer tubes containing optical fibers, the buffer tubes being arranged around a central supporting member in an oscillating helical lay pattern having a predetermined period, the method comprising the steps of:
providing a splice closure including an elongate frame and splice organizing means mounted thereon for holding one or more optical fiber splices, the frame having a predetermined length as least as great as the period of the oscillating helical lay pattern of the cable;
removing the jacket from a predetermined longitudinal portion of the cable corresponding to the period of the oscillating helical lay pattern of an underlying predetermined buffer tube to the thereby produces slack in the predetermined buffer tube;
securing the predetermined longitudinal portion of the cable to the frame;
and splicing one or more of the fibers of the predetermined buffer tube to respective one or more fibers of another fiber optic cable and securing the splices within the splice organizer means.

56. A method according to Claim 55 wherein the splice closure further comprises a housing, and further comprising the step of securing the housing around the frame and the splice organizer means.

57. A method according to Claim 55 wherein the step of providing the elongate frame of predetermined length comprises the step of adding an extensionmember to a first longitudinally extending portion of the frame on which the splice organizer means is mounted.

58. A method according to Claim 55 wherein the step of providing the splice closure includes providing second splice organizer means on the frame longitudinal adjacent the first splice organizer means.

59. A method for repairing a severed portion of a fiber optic cable of the type having one or more buffer tubes containing optical fibers, the method comprising the steps of:

providing a splice closure comprising an elongate frame, and splice organizer means on the frame for securing splices between predetermined optical fibers, the splice organizing means comprising a plurality of splice trays and first and second mounting means for mounting at least one of the splice trays in each of respective first and second longitudinally adjacent positions on the elongate frame;
securing respective first and second ends of the fiber optic cable to respective opposing ends of the elongate frame of the splice closure; and making first and second splices between a patch optical fiber and respective first and second ends of each severed optical fiber and positioning the first and second splices in splice trays at respective first and second longitudinally adjacent positions on the elongate frame;
whereby the longitudinally arrangement of the splice trays permits obtaining slack for repairing each severed optical fiber with an intervening patch optical fiber.

60. A method according to Claim 59 wherein the splice closure further comprises a housing, and further comprising the step of securing the housing surrounding the frame and the splice organizer means.