WO2013075175A1

WO2013075175A1 - Fibre optic splice closure

Info

Publication number: WO2013075175A1
Application number: PCT/AU2012/001445
Authority: WO
Inventors: Michael GAUCI
Original assignee: Afc Group Pty Ltd
Priority date: 2011-11-23
Filing date: 2012-11-23
Publication date: 2013-05-30
Also published as: AU2012343334B2; NZ626081A; AU2012343334A1

Abstract

Disclosed herein is a fibre optic splice closure comprising a splice holder having first and second opposing sides; and at least one optical fibre entry point and at least one optical fibre exit point. The closure defines a plurality of optical fibre pathways within the closure, whereby a first optical fibre can be selectively directed from the at least one entry point to either side of the splice holder and whereby a second optical fibre spliced to the first optical fibre in the splice holder can be selectively directed from the opposing side of the splice holder to the at least one exit point.

Description

FIBRE OPTIC SPLICE CLOSURE

Field of the Invention

The present invention relates to an improved fibre optic splice closure.

Background to the Invention

Telecommunications systems use fibre optic cables and digital electronics to transmit large volumes of data and voice signals over relatively long distances. What are sometimes known as "splice points" and "drop points" are often required for most fibre optic cable systems to join separate cables in order to increase the effective length of the cable, as well as to provide booster elements if required. At a splice point, all of the optical fibres at one end of a first cable are spliced to corresponding optical fibres of a second cable. At a drop point, some of the optical fibres may be spliced to a drop cable, while most of the optical fibres are passed through the drop point unaltered.

For both splice points and drop points, the optical fibres are exposed from their protective cable jacket to be spliced and secured within a splice closure. The fibre optic splice closure typically includes a protective housing with openings through which respective fibre optic cables enter and/or exit.

A major problem with known fibre optic splice closures is that the optical fibres contained in the closures can only bend gradually in either a clockwise or anticlockwise direction before being spliced to another optical fibre at the splice holder, with the other optical fibre having to gradually bend in the same clockwise or anticlockwise direction and exit the closure as if continuing in a straight pathway. This is acceptable in some circumstances, but limits all cables to the same entry of the housing and exit of the housing, while also limiting connections to one consistent respective side of the splice housing.

The preceding discussion of the background art is intended to facilitate an understanding of the present invention only. It should be appreciated that the discussion is not an acknowledgement or admission that any of the matter referred to or documents identified was part of the common general knowledge in Australia, or any other country, as at the priority date of this application. . Throughout the specification the word "comprise", or variations such as "comprises" or l "comprising", will be understood to mean the inclusion of a stated integer or group of integers, but not to the exclusion of any other integer or group of integers.

Summary of the Invention

In a first aspect, the invention provides a fibre optic splice closure comprising a splice holder having first and second opposing sides; and at least one optical fibre entry point and at least one optical fibre exit point. The closure defines a plurality of optical fibre pathways within the closure, whereby a first optical fibre can be selectively directed from the at least one entry point to either side of the splice holder and whereby a second optical fibre spliced to the first optical fibre in the splice holder can be selectively directed from the opposing side of the splice holder to the at least one exit point.

The fibre optic splice closure of the invention allows flexibility in the splicing of optical fibres by providing a closure that allows for multiple ways of connecting and directing splice ends and connections of optical fibres. It can also be seen that the invention can provide in one form an effective way of allowing redirection of optical fibres in a fibre optic splice closure while maintaining secure splice connections and limiting the curvature of cables so as to avoid cable damage. In some embodiments, the closure comprises members about which the first and second optical fibres are windable to follow the plurality of optical fibre pathways within the closure. In some embodiments, the members comprise wings adapted to retain the optical fibres. It will be appreciated that the members must be positioned within the closure in locations whereby winding of the optical fibres therearound does not result in the optical fibres being bent to a degree where damage might occur.

The members may, for example, comprise reels located adjacent the splice holder, wherein the optical fibres are windable around the reels such that they follow at least part of a figure 8 path and can thereby be selectively directed from the entry point to either side of the splice holder, and from the opposing side of the splice holder to the exit point.

The members may, for example, comprise peripheral channels within the closure.

In some embodiments, the closure further comprises a holding area for holding optical fibres which terminate within the closure. The holding area may, for example, be defined by two walls having resilient jaws that are adapted to clamp the optical fibres which terminate within the closure.

In some embodiments, the at least one entry point and the at least one exit point are the same (i.e. the first optical fibre enters the closure at the same point that the second optical fibre leaves the closure). Alternatively, the splice closure may have a number (e.g. 2, 3, 4 or more) entry/exit points, and an installer can choose the most appropriate optical fibre entry and exit points based on the particular configuration of incoming and outgoing cables at the installation site.

Indeed, a major advantage of the present invention is that the optical fibre pathways within the splice closure can allow feed of a first cable into to a first opening at a first side of the splice closure and feed to a first or second side of a splice holder and splice connection to a second cable leaving the first or second opposed side of the splice holder and exiting the first opening or a second opening at a second side of the splice closure, thus providing a choice of a change of direction of spliced cables into and out of the splice closure.

In some embodiments, the at least one entry point and the at least one exit point comprise a clamp adapted to securely clamp optical fibres passing through the at least one entry point and the at least one exit point.

In some embodiments, the closure the closure is adapted to be stacked next to (e.g. beside or on top of) another closure. In some embodiments, the closure is adapted to be pivotally connected to another closure. The closures may, for example, be adapted to be separated from each other when pivoted at a specific angle with respect to each other.

In a second aspect, the invention provides a fibre optic splice enclosure comprising two or more of the fibre optic splice closures of the first aspect located within a housing.

Also disclosed herein is a fibre optic splice enclosure having a housing that provides cable splice protection means including one or more cassettes with connections for plurality of cassettes into a stack forming an enclosure, wherein the enclosure includes:

a) an entry and an exit means for receiving a fibre optic to be spliced to a further fibre optic; b) a splice holder for holding the spliced fibre optics and having a first side for receiving a first fibre optic feeding from or leading to the entry or the exit means; and c) a directions means for redirecting a fibre optic from to another side of the splice holder wherein the fibre optic splice enclosure can selectively direct fibre optics to selective sides of the splice holder for selective connections and selective directions to and from the enclosure.

The direction means can allow feed of a first cable to a first side of a splice holder and splice connection to a second cable leaving the second opposed side of the splice holder.

The direction means can allow feed of a first cable to a second side of a splice holder and splice connection to a second cable leaving the first opposed side of the splice holder and thereby providing a change of direction of spliced cables. The direction means can allow feed of a first cable into to a first opening at a first side of a splice enclosure and feed to a first or second side of a splice holder and splice connection to a second cable leaving the first or second opposed side of the splice holder and exiting the first opening or a second opening at a second side of the splice enclosure and thereby providing a choice of a change of direction of spliced cables into and out of the fibre optic splice enclosure.

The direction means can include pathways including peripheral channels directing cables in a broad arcuate manner. The direction means can include a plurality of guide means that allow predefined limit on arcuate minimum curvature to prevent excessive curvature and damage to the fibre optic capabilities of the cables. In one form the plurality of guide means can be in pairs so as to allow cable to follow at least a part of a figure 8 path.

Brief Description of the Drawings

Preferred embodiments of the invention will now be described, by way of illustration of the invention only, with reference to the accompanying drawings, in which:

Figure 1 is a perspective view of a fibre optic splice closure in accordance with an embodiment of the invention; Figure 2 is a perspective view of the fibre optic splice closure of Figure 1 having a lid; Figure 3 is an enlarged view of the hinge mechanism of closures of Figure 1 stacked and hinged together; Figure 4 is an enlarged view showing the entry/exit point of the fibre optic splice closure of Figure 1 ;

Figure 5 is a diagrammatic view of one group of pathways of optical fibres when using the fibre optic splice closure of Figure 1 ;

Figure 6 is an overhead plan view of a fibre optic splice closure in accordance with a second embodiment of the invention;

Figure 7 is a perspective view of the fibre optic splice closure of Figure 6 with an open lid;

Figure 8 is a perspective view of a plurality of the fibre optic splice closures of Figure 6 stacked together and hinged with an open top closure and lid; and

Figure 9 is a perspective view of the spring closures of the closure of Figure 6.

Detailed Description of Embodiments of the Invention

Referring to firstly to Figures 1 to 4, there is shown a first embodiment of a fibre optic splice closure of the invention in the form of fibre optic splice cassette 11. Cassette 11 has a housing 20 formed by a generally planar plate with upright peripheral walls and a splice holder 25 for holding the spliced ends of first and second optical fibres or spliced optical fibres connected thereto. The tray 20 has a plurality of entry and exit openings 22, 23 in the periphery walls of the tray 20 to allow entry and exit of the first and second optical fibers (or cables) and/or optical fibres (or cables) connected thereto. The cassette 1 1 includes a number of members which define a plurality of optical fibre pathways within the tray 20. These members include a plurality of reels in the form of hubs 31 , 32 for directing the first and second optical fibres or optical fibres connected thereto to the splice holder 25, as well as to and from the plurality of openings 22, 23 in a manner to prevent excessive curvature and damage to the optical fibres. The hubs 31 , 32 are shaped and are positioned in the tray 20 such that optical fibres wound around the hubs have an arcuate maximum curvature to prevent damage to the fibres cables. The hubs 31 and 32 are spaced from each other so as to allow optical fibres wound therearound to follow at least a part of a figure 8 path (as will be described below). The hubs 31 , 32 have wings 35, 36, and 37 (identified only on hub 32 for clarity) that extend radially from a central body of the hubs and which can encapsulate the optical fibres around the central body. This prevents tangling of the optical fibres and the subsequent risk, of them being bent to angles of greater curvature that could damage the optical fibres.

The members also include walls within the tray 20 which define peripheral channels 41 , 42, 43, 44 around an outer edge of the tray 20. Peripheral channels 4 , 42, 43, 44 can direct the optical fibres within the tray 20 in a broad arcuate manner from the openings 22, 23 around the periphery of the tray 20. Peripheral channels 41 , 42, 43, 4 are wide enough to accommodate the required amount of optical fibres. For example, they may be wide enough to accommodate up to 24 1.5 meter lengths of 900 m fibres. The hubs 31 and 32 are spaced from each other and the peripheral channels 41 , 42, 43, 44 so as to allow the optical fibres to follow paths within the cassette 11 that provide the advantages discussed herein.

The cassette 1 1 has hinges 51 , 52 so that a first cassette 1 1 can be hingedly attached to a second cassette 1 1 to form a multi-level cassette (as can be seen in Figures 3 and 8). As can be seen in Figure 2, a lid 12 may also be attached to the cassette 1 1 (or to the uppermost cassette in a stack of cassettes). The cassette 11 (or a number of the cassettes 1 1 , optionally stacked together) may be contained within a housing (not shown) in circumstances where the cassettes need additional protection (e.g. if exposed to harsh environmental conditions or if there is a risk of accidental impacts).

As shown in Figure 5, in one usage of the cassette 11 , a first optical fibre can be fed into to a first side of a splice holder 25, where it can be spliced to a second optical fibre leaving the second opposed side of the splice holder 25. However, importantly, the hubs 31 , 32 and the peripheral channels 41 , 42, 43, 44 can also allow feed of a first cable to a second side of a splice holder 25, where it can be spliced to a second optical fibre leaving the first opposed side of the splice holder 25, resulting in a change of direction of spliced fibres. As will be appreciated, the figure of 8 configuration of the optical fibre around hubs 31 , 32 enables the optical fibre to be fed into either side of the splice tray 25. In this manner, it is possible to reverse the fibre direction within the cassette 1 1. Further, excess optical fibre can easily be stored within the cassette 1 1 by winding it around hubs 31 , 32, which may simplify installation of the fibre optic splice closure.

Further, a first cable fed into a first opening 22, 23 at a first side of cassette 1 1 and then feed to a first or second side of a splice holder 25 and splice connection to a second cable leaving the first or second opposed side of the splice holder and exiting the first opening or a second opening 22, 23 at a second side of the cassette 1 1 and thereby providing a choice of a change of direction of spliced cables into and out of the cassette 1 1.

Referring now to Figure 4, there is shown in greater detail one opening 23 which is a break in the upright peripheral wall of the tray 20. It is important to control the cables that are fed through opening 23 (and 22) to prevent any pulling, stretching or jamming of cable within the cassette 1 1. As such, cassette 1 also has closing means 28 that, in the embodiment shown, is a spring loaded closure that softly clamps the cable which passes through the opening 23. An embodiment of the closing means is described in further detail below.

Cassette 1 1 also has a splice end holder 49. This is located adjacent the splice holder 25 and, in use, can hold optical fibres that are presently spare and not required yet for splicing. However by having them in location and leading from spliced cables they can readily be made operative and reconfigured into the splice holder or otherwise. The splice end holder 49 is formed at the end of the wall forming the peripheral channels 41 , 42, 43, 44 and has resilient plastic jaws with a soft flexibility to ensure a secure hold but one which is not detrimental to the optical fibre.

An alternate embodiment of a fibre optic splice closure of the invention is shown in Figures 6 to 9 in the form of cassette 61. Cassette 61 has a number of similar features to cassette 1 1. Cassette 61 has a housing 70 formed by a planar cassette plate with upright peripheral walls and including within the walls a splice holder 75 for holding the spliced ends of first and second optical fibres or spliced optical fibres connected thereto. The housing 70 has a plurality of entry and exit openings 72, 73 in the periphery walls of the housing 70 and opposed sides to allow entry and exit of the first and second cables or cables connected thereto.

The splice enclosure 61 includes a plurality of hubs 81 , 82 for directing the first and second optical fibres, or optical fibres connected thereto to the splice holder 75, as well as to and from the plurality of openings 72, 73 in a manner to prevent excessive curvature and damage to the optical fibres. As shown in Figure 7, cassette 61 can have a lid 62, which covers and protects the contents of the cassette 61. As shown in Figure 8, the cassette 61 is stackable to produce a stack of cassettes 61 which are hingedly connected to each other via hinges 101 , 102 to form a multi-level cassette (optionally with a lid 62 on the uppermost stacked cassette).

Cassette 61 does not have peripheral channels similar to those of cassette 11. Instead cassette 61 provides hubs 81 , 82 that are positioned to limit the arcuate minimum curvature of cables within the cassette 61 and hence prevent excessive curvature and damage to the optical fibres. The first and second optical fibres can be folded around the hubs 81 , 82 and directed in any desired direction in the manner described previously. Hubs 81 , 82 can include wings 85, 86, and 87 extending radially from a central body of the hubs and providing a encapsulating means to hold the optical fibres around the central body. The hubs 81 and 82 are spaced from each other, the splice holder 75 and the periphery wall of the cassette 61 and cooperate with each other in a pair so as to allow optical fibres to follow at least a part of a figure 8 path, as discussed previously in respect of Figure 5.

A wall of cassette 61 adjacent the splice holder 75 has soft flexible end resilient plastic jaws, which forms a splice end holder 83, similar to splice end holder 49 of cassette 11.

It can be seen from Figure 9 that cassette 61 has similar entry and exit openings 72, 73 as entry and exit openings 22, 23 of cassette 11. The entry and exit openings 72, 73 in cassette 61 are closed by closing means 78. This closing means includes a finger plate 78A mountable on a slide body 78B which longitudinally engages with spring 78C. The elements of the closing means 78 are mounted in a channel 79A adjacent to the entry and exit openings 72, 73. The channel 79A includes a groove 79 into which a rib (not shown) on the underside of slide body 78B can be received. In this way the spring 78C engages against the body of the cassette 61 and urges the closing means 78 into a position where the entry and exit openings 72, 73 are closed. Slide body 78B has a rubber press 78D at its end, beneath the finger plate 78A, and a similar opposing rubber press 79C is mounted adjacent the entry and exit openings 72, 73. Ehen in the closed position, rubber presses 78D and 79C grab and enclose in an enveloping manner the optical fibres extending through the openings 72, 73. In this way, the jaw action prevents excess optical fibre extending into the cassette 61 , which might cause damage by introducing excessive lengths of cable/fibres into the cassette. Further it prevents or substantially minimises the retraction and possible disconnection of spliced fibre optics. Thirdly it substantially seals the fibre optics in the cassette.

As noted above, cassettes 1 1 and 61 have hinges 51 , 52 and 101 , 102 for connection of one of a plurality of cassettes to form a multi-level cassette or a lid 12, 62. As the cassettes - typically need to be accessible to undertake splicing connections, checking or reconnection in different configurations, it is beneficial to allow a cassette to remain open at an angle in order to provide ready access therein. Further it is beneficial to allow ready disconnection and removal and or replacement of individual cassettes. This dual mechanism is provided by each cassette and lid having a hinge mechanism which has two parts, as can best be seen in Figure 3. The first is an open pivoting cavity 52 and the second is an oval shaped pin 53 for mounting in the cavity 52. However as the pin 53 is oval and has a cross sectional width greater than its cross sectional length, the opening of the cavity 52 must be about the dimension of the smaller cross sectional width and the internal diameter must be greater than the greater cross sectional width of the pin 53. In this way the pin can only exit at one angle where the smaller cross section matches the opening. Further there can be , rotation of the pin and therefore the attached lid or cassette relative to the attached lid or cassette. This rotation can be effected by altering the internal dimensions of the cavity 52 in a manner similar to a cam surface for enabling opening to be maintained at preferred angle. Those persons skilled in the art will appreciate that any modifications or changes to the particular embodiments of the fibre optic splice enclosures described above which could be made without the need for inventiveness or without departing from the spirit of the invention, are included within the scope of the invention.

Claims

CLAIMS:

1. A fibre optic splice closure comprising:

a splice holder having first and second opposing sides;

at least one optical fibre entry point and at least one optical fibre exit point;

the closure defining a plurality of optical fibre pathways within the closure, whereby a first optical fibre can be selectively directed from the at least one entry point to either side of the splice holder and whereby a second optical fibre spliced to the first optical fibre in the splice holder can be selectively directed from the opposing side of the splice holder to the at least one exit point.

2. The fibre optic splice closure of claim 1 , wherein the closure comprises members about which the first and second optical fibres are windable to follow the plurality of optical fibre pathways within the closure.

3. The fibre optic splice closure of claim 2, wherein the members comprise reels located adjacent the splice holder, wherein the optical fibres are windable around the reels such that they follow at least part of a figure 8 path and can thereby be selectively directed from the entry point to either side of the splice holder, and from the opposing side of the splice holder to the exit point.

4. The fibre optic splice closure of claim 2 or claim 3, wherein the members comprise

peripheral channels within the closure.

The fibre optic splice closure of any one of claims 2 to 4, wherein the members comprise wings adapted to retain the optical fibres.

The fibre optic splice closure of any one of the preceding claims, wherein the closure further comprises a holding area for holding optical fibres which terminate within the closure.

The fibre optic splice closure of claim 6, wherein the holding area is defined by two walls having resilient jaws that are adapted to clamp the optical fibres which. terminate within the closure.

8. The fibre optic splice closure of any one of the preceding claims, wherein the at least one entry point and the at least one exit point are the same.

9. The fibre optic splice closure of any one of the preceding claims, wherein the at least one entry point and the at least one exit point comprise a clamp adapted to securely clamp optical fibres passing through the at least one entry point and the at least one exit point.

10. The fibre optic splice closure of any one of the preceding claims, wherein the closure has a lid.

11. The fibre optic splice closure of any one of the preceding claims, wherein the closure is adapted to be stacked next to another closure.

12. The fibre optic splice closure of any one of the preceding claims, wherein the closure is adapted to be stacked on top of another closure.

13. The fibre optic splice closure of any one of the preceding claims, wherein the closure is adapted to be pivotally connected to another closure.

14. The fibre optic splice closure of claim 13, wherein the closures are adapted to be

separated from each other when pivoted at a specific angle with respect to each other.

15. A fibre optic splice enclosure comprising two or more of the fibre optic splice closures of any one of claims 1 to 14 located within a housing.