MXPA99009747A - Fibre optic splice closure - Google Patents

Abstract

A closure assembly for encapsulating splices between optical fibres of one or more fibre optic cables, the assembly comprising first and second hollow cover portions having mating surfaces which can be sealed together around the fibre optic cable(s), wherein one or both of the cover portions is provided with splice retaining means for securingthe said optical fibre splices.

Description

FIBER OPTIC SPLASH CLOSURE This invention relates to a closure assembly for a palm on one or more fiber optic cables. A fiber optic cable comprises a plurality of optical fibers contained within an outer protective liner, usually with an intermediate mechanical protection layer between the fibers and an outer liner to prevent the fibers from breaking during the installation or use of the cable. When it is desired to form a splice for one or more of the optical fibers of the cable, it is necessary to remove the outer lining and the mechanical protection layer for the access of the fiber or fibers that will be spliced. The exposed optical fibers of the resistors need to be protected not only against the environment, but also against overflection that could break the fibers or result in signal attenuation. The fiber optic palm closures, therefore, should be designed to meet these needs. Known fiber optic splice closures typically comprise a hollow container containing one or more protective splice trays. The splice trays store the fiber optic splices and can also store any uninterrupted, but exposed optical fiber. For example, in a branched splice, the splice tray can store not only the fiber optic splices but also those fibers stripped of the outer cable sheath, which do not have the same splice. When the outer cable jacket is removed to form a fiber optic cable of a fiber optic cable using a splice closure, it is usual to include an excess length of stripped fibers within the closure, both spliced fibers like any uninterrupted fiber. This provides a future message or other changes of place in the network. This excess fiber usually formed in one or more loops and is stored in the splice tray in a linked configuration. US 4805979 (Minnesota Mi ni ng and Manufactu ring Corp) discloses a standard known optical fiber splice closure. Which comprises a base and a cover which are in the form of half wraps having adjustment surfaces secured by bolts. At the base of the splice closure, one or more splice trays are attached, comprising channels receiving the spreads extending along the tray and the retention lips of the fibers extending around at least part of the edge of the tray. the tray . According to US 4805979, where a branched splice is made, the fibers that can be joined are spliced and placed in the channels receiving the splice from the splice tray and the fibers that are not going to The seaboard, together with the excess length of the spliced fibers, are rolled and placed under the lips that retain the fiber around the periphery of the tray. EP-A-01 59857 (Raychem) discloses a fiber optic splice closure comprising a base through which cables run and a dome-shaped closure that fits over the base. Within the closure a plurality of hinged splice trays are provided to hold the fiber optic splices. The closure is efficient and effective to wax a large number of joints, but it is somewhat bulky. We have discovered that it is possible to form a particularly compact and useful splice closure by incorporating the function of the splice tray in the cover portions that form the closure of the fiber optic splice. That is, one or more portions of the outer cover (i.e., parts of the outer housing of the splice closure itself) may comprise a splice storage tray. Therefore, the present invention provides a closure assembly for encapsulation splices between the optical fibers of one or more fiber optic cables, the assembly comprising the first and second hollow cover portions having fitted surfaces which can be sealed together around of fiber optic cables, wherein one or both of the first and second cover portions are provided with the splice retention means for securing the fiber optic splices. According to the present invention, therefore, one or both cover portions are adapted not only to perform the function of a cover, but also to act as a splice tray. Since the function of the splice tray and the function of the closed cover are provided by the same part, the cost of providing separate parts is avoided. In addition, the resulting closure is compact. In this specification, the term "loose optical fibers" refers to the excess lengths of spliced optical fibers and / or spliced optical fiber lengths (sometimes referred to as "firm" optical fibers) that are normally included in a Fiber optic splice closure. The excess lengths of the splicing fibers result in the need to provide fibers of sufficient length in order to carry out the splicing operations (e.g., fusion splice) and also in order to provide splice to future, etc. In addition, firm fibers without splicing that are stored in the closure may be necessary to cut and join in the figure. "Loose optical fibers" are preferably contained in tubes and these tubes are sometimes referred to as "loose tubes" (hereinafter the term "loose fibers"). In one embodiment of the invention, only one of the first and second cover portions is adapted to a splice tray to secure the fiber optic splices. Preferably, in this embodiment, the other cover portion fits a stored tray for storage lengths of the loose optical fibers. The other cover portion is adapted to be a storage tray being provided with the retention means of loose fibers, e.g., in the form of lips or projections.

In another embodiment, both the first and second cover portions are adapted to be splice trays to secure fiber optic splices. To this end, both cover portions are provided with splice retaining means. In this embodiment, an additional fiber storage tray is preferably provided to store any length of loose optical fiber, the additional tray being provided with loose fiber holding means. In addition to being provided with splice retaining means (and therefore being adapted to the splice trays), the first and / or second cover portion is also provided with the loose fiber retention means (and therefore, is adapt to a storage tray). Conveniently, for example, a cover portion that adapts to both the splice tray and the storage tray that can store any excess length of the splicing fibers, while storing the fibers without splicing (sometimes also splicing). known as "firm" fibers) that can be accommodated in any other deck portion or in an additional separate storage tray. The cover portions are hollow and have fitting surfaces that can be sealed together around the fiber optic cables. Preferably, the cover portions generally have a similar shape. In a preferred embodiment, one or each cover portion is generally elongated, having a substantially planar main surface and side walls that extend inwardly from the elongated edges of the planar major surface. In preferred embodiments the portion or each cover portion is tapered at one or each of its ends. This arrangement can improve the sealing of the cables. The means for retaining the splice in the cover portions to fit the input tray take any convenient form. Suitable means will be apparent to those skilled in the art. In one embodiment according to the present invention, the cover portion is provided with two vertical flanges extending substantially parallel to one another along with at least part of its length. The resilient material, for example, foam, can be provided between the straight flanges, which are in use, the fiber splices are placed in order to secure them. The spacing of the vertical flanges and the thickness of the foam, or other resilient material is selected according to the size of the splices so that the resilient material can be slightly compressed in order to insert the splices. This makes it easier for the installer to insert the splices, while retaining them securely in place during the service life. The parallel vertical tabs can be curved or straight, according as desired to ensure the optimal splice. One of the parallel vertical tabs may be provided by the wall of the cover portion. Each portion of the cover which fits the splice tray may be provided with one or more pairs of parallel vertical tabs in order to accommodate the fiber splices. Where one or each cover portion is also adapted to the storage tray, or where an additional storage tray is provided, the storage function is preferably provided by extending edges or projections that are capable of supporting the loose fiber. . The edges or projections are means that retain the loose fiber. The edges or projections are preferably adapted to support the loose fiber in a linked configuration. This minimizes the possibility of damaging the fibers, or signal attenuation, both of which could result in overflection of the fibers. The cover portions can be secured with each other by any suitable means. For driving convenience, the cover portions preferably are pivotally connected, e.g., hinged together. For the preferred embodiment of the generally elongated cover portions, the cover portions are preferably pivotally connected along a longitudinal axis. A pivotal connection means that the two cover portions are joined, and therefore are handled as one piece, but allows the cover portions to be fully opened, eg, on a flat surface, allowing easy access to the splice tray region and storage tray region.

Where a separate storage tray is provided, in addition to two cover portions, the separate storage tray is preferably also pivotally connected, e.g., hinged, to the two cover portions. The pivotal connection preferably such as the two cover portions exposed on a substantially flat surface and the additional storage tray project up (or down) thereof. The additional storage tray may preferably be in a position substantially perpendicular to the extended cover portions. This makes it easier for an installer to access and work inside each deck portion and the additional storage tray. This pivotal connection arrangement is preferably provided by a connection plate or when the storage tray is mounted. The connection plate is preferably provided with pivot means and sliding means. The pivoting means allows the storage tray for the pivotal ratio for each cover portion and the sliding means to leave the storage tray for the relationship that slides transversely to each portion of the cover, at least when the storage tray it has been observed that it pivots in an orientation when it is substantially parallel with the cover portion. The sliding mechanism allows the cover portions to move forward one with the other in order to close the assembly. The pivotal and sliding design provides a splice closure that is compact and easy to handle because it is one-piece, but also which allows full and easy access to the splice tray and storage tray regions. The preferred pivoting arrangement (e.g., hinge) secures preferred elongated cover portions along an edge. The securing along the other edge can be provided by any suitable means. As an example, cover portions with adjustment projections can be provided. Preferably, the security means are such that they allow them to be easily reopened to work later on the splice closure. The closure assembly, according to the present invention, can be formed to close any type of splice, eg, an in-line splice, a hinge splice or a branched splice. In preferred embodiments, therefore, the cables project from one or both ends of the splice closure. In addition, to secure the cover portions with each other, the cover portions can be sealed with one another. This can be done in many ways, as would be apparent to those skilled in the art. In a preferred embodiment according to the invention, the adjusting surfaces of the first and second cover portions respectively are in the form of a tongue and groove, and are provided with a strip of sealing material within the tongue and groove. This sealing material may, for example, be a rubber, a gel, a polymeric foam or a combination thereof. Therefore, it is preferably a seal around the wires where they enter the closure, which may also be rubber, gel, polyfoam foam, etc. where a gel is used, preferably it is a thermoplastic gel. A preferred polymer foam is foam. silicone rubber Although the cover portions are preferably connected, vg, pivotally, with one another to facilitate handling, this connection is preferably removable. This makes it possible to provide interchangeable cover portions, which can be selected according to the assembly of desired closure for a particular operation For example, the cover portions can be provided adapted to the classic in-line splice trays, ejection trays, storage trays, etc. Therefore, a second aspect of the invention provides a set of parts comprising three or more deck portions, either of which can be used together to form a closure assembly for fiber optic splices, each cover portion being provided with an adjustment surface for sealing another of the cover portions and being adapted to provide different functions in the assembly. of closure, preferably at least a portion of cover in the equipment of parts is adapted to a splice tray A third aspect of the invention provides a method of encapsulation of splices between the optical fibers of one or more fiber optic cables using a closure assembly according to the first aspect of the invention, the method comprising (i) splicing optical fibers and securing them in the splice retention means of the portion or each cover portion, and; (ii) sealing the fitting surfaces of the cover portions with each other. The closure assembly of the present invention is compact and easy to use. However, it can be easily used to contain up to approximately 24 splices or more. The embodiments of the invention will now be described, by way of example, in which: Figures 1, 2 and 3 are each, perspective views showing three different embodiments of closure assembly according to the invention, each in turn; open configuration; Figure 4 is a cross-sectional view through the region retaining the fiber optic splice of each of Figures 1 to 3, taken along line IV-IV of each of Figure 1 to 3; Figure 5 shows the closed configuration of each of the closed assemblies of Figures 1 to 3; Figures 6a and 6b are schematic cross-sectional views showing the assembly of the main component parts of the closure assembly of Figure 2; Figures 7a, 7b and 7c are schematic cross sectional views showing the assembled assembly of Figure 6 in the closed, partially open and fully open configuration, respectively; Figures 8a and 8b are schematic perspective views of part of the main component of the closure assembly of Figure 2, showing the assembly of those parts of the component; and Figures 9a, 9b and 9c, are schematic perspective views, showing part of the assembled closure assembly of Figure 8 in the closed, partially open and fully open configurations, respectively. Referring now to the drawings, Figure 1 shows a first embodiment of closure assembly according to the present invention, which comprises the first and second cover portions 2, 4 in the form of middle wraps. The cover portions 2 and 4 have sealing surfaces 6 that can be sealed with one another. The manner in which the sealing of the adjustment surfaces 6 is carried out is described below. Each cover portion 2, 4 is generally elongated and has a substantially planar main surface (not visible in the figure) and side walls 8 extending forward of the main surface to the adjustment surfaces 6. The cover portion 2 is provided with a pair of elongated, straight, parallel vertical tabs 10 containing a resilient foam channel 12 therebetween. The fiber optic splices 14 are placed between the vertical flanges 10, 10 ', and the resilient foam 12 firmly secures the splices in place. The vertical flanges 10, 10 'in combination with the foam 12, therefore, provide means for retaining the splice in the cover portion 2. The safety of the splices by the foam 12 and the flanges 10, 10' are described in FIG. more detail with reference to Figure 4. In the embodiment shown in Figure 1, one of the vertical flanges 10 'is provided by the side wall 8 of the cover portion 2. The cover portion 2 is also provided with edges and projections 16, 18 which store loops of lengths of the fiber 20 in the route of the splice region. The cover portion 4, in contrast, is not provided with the retention means of the splice. Instead of this, it is provided with projections 22 which act as storage media for loose fibers. The projections 22 contain loops of excsive lengths of fiber that are advantageously retained in the splice closure for future rearrangements. The excess fiber lengths of the splicing fibers may be contained in the cover portion 4 and / or also the fiber lengths without excess splicing, or so-called "firm" fiber. Figure 1 is an in-line splice and two fiber optic cables between the closure of each end. The cover portion 4 is provided with a sealing material 26, e.g., a gel or rubber to seal around the cables 24. The sealing material 26 contains channels for receiving the cables 24. In addition, the retaining strips 28 are wrapped around the cables to secure the cables and secure them to the cover portions of the closure. The retaining strips 28 also serve to retain the sealing material 26 in place (which is particularly useful when the sealing material is gel). Within the splice closure the outer lining of the fiber optic cable is removed and the optical fiber lengths are exposed. The excess fiber loops are organized in the storage region provided by the cover portion 4 and the fibers of the splice are led into the cover portion 2 and the splices arranged as described above. Once the splicing operation is completed the cover portions 2 and 4 can be brought closer so that the adjustment surfaces 6 are sealed together to seal the closure. The sealed closure is the last shown as Figure 5. The cover portions 2 and 4 are provided with hinges 30 that allow the cover portions 2 and 4 to be opened and flattened for easy access. Therefore, the embodiment of Figure 1 provides a splice closure for an in-line splice wherein one liner at the middle of the cover portion 2 is the splice tray and the other liner at the middle of the cover portion. 4 is the storage tray. The organization of the storage tray is on the same plane as the entrance plane of the cables, which are simple and prevent cables or fiber from being overflected. The overall design is compact and easy to use.

Figure 2 shows another embodiment of the splice closure according to the invention. Similar reference numbers are used to refer to a similar part compared to Figure 1. In this embodiment the cover portions 2 and 4 are provided with retention means of the splice 10, 12 (not visible on the cover portion 4) and a separate storage tray 32 is provided for the storage of excess length of the loose optical fiber. As in Figure 1 the cables 24 between the closure in the plane of the organization storage tray, which in the embodiment of Figure 2 is an additional tray 32 and in the embodiment of Figure 1 was a cover portion 4. The cover portions 2 and 4 and the additional tray 32 are hinged at 30 in a way that allows the cover portions 2 and 4 to be placed flat, while the additional storage tray 32 projects perpendicularly. This engozne mechanism is described in greater detail later. The modality of Figure 2, as in Figure 1, is an in-line splice of two internal cables, two external cables. Figure 3 describes another embodiment of splice closure according to the invention. Again, similar reference numbers are used to refer to similar parts as compared to Figures 1 and 2. The splice closure of Figure 3 is for a branched connection and links fibers of a straight main cable 34 of those of two cables branched 36. As before, the cover portion 2 acts as a splice tray. The cables enter the closure in the plane of the cover portion 4 In this embodiment, the main cable passes straight (with tapered fibers for splicing the branched cables) and are not excess fiber loops stored in the cover portion 4 Figure 4 is a cross-sectional view taken along the lines IV-IV of the preceding Figures, showing the retention means of the splice. The vertical tabs 10, 10 'contain a channel-like layer of the foam 12, within from which the fiber splice 14 is inserted Figure 5 shows the sealed closure of Figures 1 to 23 The cover portions 2 and 4 are sealed again with each other The design is very compact, although the closures of the Figure 1 to 3 can be used to contain, for example, up to about 24 splices, or more. Figures 6a and 6b, show the assembly of the component parts of the assembly of Figure 2, that is, the assembly comprising the portions of cover 2 and 4 and a separate storage tray 32 The storage tray 32 is mounted on a connecting plate 30 having two pivot points 40 The connecting plate 30 is provided at each end with a resilient projection 40 which is pushed in, and it is secured against a part 44 on each of the cover portions 2 and 4. By pressing the projection 42, the connection plate 30 can be removed from the closed position, i.e. the connection plate 30, and therefore, the Storage tray 32 is detectably connected to cover portions 2 and 4. The assembled configuration is shown in Figure 6b. The cover portions 2 and 4 can be pivoted about the points 30 in relation to the storage tray 32. The cover portions 2 and 4 are also transversally connected in relation to the storage tray 32, ie in a direction towards below the page of the figure The cover portions are shown in the space position at the maximum of the storage tray 32 in Figure 6b, with the projection 42 on the connection plate 30 abutting against the part 44 on the portions of cover 2 and 4.

Figures 6a and 6b also illustrate the nature of the tongue and groove of the adjustment surfaces of the cover portions 2 and 4, the tongue being indicated by the reference number 46 and the groove by the reference number 48. A strip 50, eg, rubber (e.g., silicone rubber foam) or gel, or a combination thereof is also included in slot 48.

Figures 7a, 7b and 7c show the assembled parts of Figures 6a and 6b in the closure, in the partially open and fully open position, respectively. To form the fully closed position of Figure 7a for the fully open position of Figure 7c, the cover portions 2 and 4 are first transversely spliced relative to the input tray 32 to the projection 42 on the plate 30 abutted thereon. points in the position of Figure 7c. This is that the fully open position with the cover portions 2 and 4 in the opposite plane and the storage tray 32 projecting perpendicularly. This allows easy access. The detectable nature of the connection of parts 2, 4 and 32 is advantageous in that it allows different combinations of cover portions put together to form different functions, eg, in-line splicing, branching, storage, etc. Figures 8a and 8b are perspective views corresponding to Figures 6a and 6b showing the assembly of the component parts of the closure of Figure 2. Similar reference numbers refer to like parts and the discussion of Figures 6a and 6b directly applied. Figures 9a, 9b and 9c are perspective views corresponding to Figures 7a, 7b and 7c, showing the assembled parts of Figure 8 in closed, partially open and fully open configurations, respectively. Similar reference numbers refer to similar parts and the discussion of Figures 7a to 7c apply directly.

Claims (10)

1. CLAIMS 1. A closure assembly for enclosing and retaining the fiber optic splices, the assembly comprising a first hollow cover portion (2) and a second hollow cover portion (4), the cover portions (2, 4) having adjusting surfaces (6) for forming the closure, characterized in that the first (2) and second (4) cover portions are connected by means of a connection plate (30), the connection plate being connected to the splice in relation to the first (2) and second (4) cover portions respectively thus allowing the cover portions to be connected in a separate apart position or in a substantially closed position, the connection plate (30) further being provided with two means of separate pivoting (40) thus allowing the first and second (2, 4) pivot cover portions in relation to each other when in the separated position. Closing assembly according to claim 1, wherein the connection plate (30) only allows pivoting when the first and second cover portions (2, 4) are in the separated position. 3. The closure assembly according to claim 1 or 2, wherein the connection plate (30) is detected in contact with the cover portions (2, 4). 4. Closing assembly according to claim 1, 2 or 3, wherein a storage tray (2) is mounted on the connection plate (30). 5. The closure assembly according to claim 4, wherein the storage tray (32) has the means for retaining the loose fiber. Seal assembly according to any of the preceding claims, wherein at least one of the cover portions (2, 4) are provided with splice retaining means (10, 10 ', 12) for the retention of Fiber optic splices (14). The closure assembly according to claim 6, wherein only one of the cover portions (2, 4) is provided with the retention means of the splice (10, 10 ', 12) and the other of the portions of Cover is provided with means that retain loose fiber for stored lengths of loose optical fiber. 8. Closing assembly according to claims 1-6, wherein both the first (2) and the second (4) cover portions are provided with the retention means of the splice (10, 10 ', 12) to ensure the fiber optic splices (14). Closing assembly according to any of claims 6-8, wherein the splice retention means (10, 10 ', 12) comprise two substantially parallel vertical flanges (10, 10') and preferably a resilient material (12) between the flanges, the fiber optic splices (14) being placed, in use, within the resilient material (12). Closing assembly according to any of the preceding claims, wherein the connection plate (30) is provided at each end with a resilient projection (42) that can be pushed and secured against a portion (44) on each of the cover portions (2, 4).