RO118986B1 - Closing device for optic fibre connection - Google Patents

Abstract

The invention relates to a closing device for one or more optic fibres. For the purpose of encasing and protecting the connections between the optic fibres of one or more optic fibre cables, the closing device consists of two tray-shaped covers (2 and 4) having conjugate surfaces which can be sealed from one another, around the optic fibre cables. One or more covers (2 and 4) can be provided with retaining means (10, 10' and 12) for ensuring said optic fibre connections (14). A storage tray (32) mounted on a connecting plate (30) is hingedly joined with the two covers (2 and 4) which, in completely open position can be arranged in the same plane, the storage tray (32) being oriented normal to this plane. Both covers (2 and 4) can be provided with means (10, 10' and 12) for securing the optic fibre connections (14) and the storage tray (32) is provided with some means for fixing the optic fibres.

Description

The present invention relates to a closure device for a connection with one or more fiber optic cables.

An optical fiber cable typically comprises multiple optical fibers contained within an outer protective shell, which usually has an intermediate mechanical protective layer between the fibers and an outer shell to prevent fiber breakage during cable installation or use. In cases where it is desired, in order to make a connection with one or more of the optical fibers of the cable, it is necessary to remove the outer casing and the mechanical protective layer in order to have access to the fiber or fibers to be connected. The resulting optical fibers, which result in this, must be protected not only from the action of the environment, but also from excessive bending that can lead to fiber breakage or signal attenuation. The closing devices for fiber optic connections must, for these reasons, be designed in such a way as to meet these requirements.

The closures for fiber optic connections typically comprise a hollow casing inside, consisting of one or more trays for supporting and protecting the connections. Connector trays support fiber optic connections and can also store other uninterrupted but exposed fiber optics. For example, in the case of a branch connection, the connection tray can support not only the fiber optic connections, but also those fibers from which the outer sheath of the cable was removed, but which were not connected as such. If the outer sheath of the cable is removed to make a connection with the optical fibers of an optical fiber cable using a closure device for joints, it is common to include in the closure device additional portions of non-insulated fibers, both interconnected fibers and other uninterrupted fibers. This is intended to ensure a supply of material for future connections or other redistributions in the network. These additional fiber portions are usually placed in the form of one or more loops and are stored on the winding plate.

US 4805979 (Minnesota Mining and Manufacturing Corp) describes a typical, known, closure device for fiber optic connections. It comprises a base plate and a lid which both have the shape of semi-carcasses with conjugated surfaces assembled together by bolts. The base plate of the coupling device is fixed to one or more coupling trays, comprising channels for receiving the couplings located along the plate, and retaining ribs of the fibers located at least part of the edge of the tray. According to US 4805979, when a branch connection is made, the fibers to be joined are connected and placed in the channels for receiving the connections from the connection tray, and the fibers that are not to be connected, together with the spare portion of the connected fibers, are wrapped. and placed under the fiber retaining ribs along the periphery of the storage tray.

EP-A-0159857 (Raychem) describes a fiber optic connection device comprising a base plate through which the cables pass, and a dome-shaped closing device which is mounted on the base. Inside the closure device there are provided several hinged trays for supporting the fiber optic connections. The closing device is efficient and useful for closing a large number of connections, but is somewhat bulky.

It has been found that it is possible to make a closure device for connections, particularly compact and useful, by incorporating the function performed by the trays for connections, in the lid that forms the closure device for optical fiber connections.

In other words, one or more lids (for example, even parts of the outer casing of the sealing device) may include the socket for the sockets.

RO 118986 Β1

Thus, the present invention relates to a closure device for sealing the connections between the optical fibers of one or more optical fiber cables, the device 50 comprising a first and a second lid, hollow inside, having conjugate surfaces which can be sealed together. Around the fiber optic cable (s), in which one or both lids are provided with means for securing the fittings, to ensure the aforementioned optical fiber connections.

For these reasons, according to the present invention, one or both lids are adapted 55 not only to fulfill their function of lid but also to support, as a tray, the fiber optic connections. Since the function of the tray-holder for the connections and the cover of the device are performed by the same element, the cost of supplying separate parts is avoided. In addition, the resulting device is compact.

In the following description, the expression "free optical fibers" refers to the Supplementary portions of the connected optical fibers and / or to the portions of unconnected optical fibers (sometimes referred to as "express" optical fibers), which are commonly included. in a closure device for fiber optic connections. The additional sections of the connected fibers are the result of the need to provide sufficient lengths of fiber in order to be able to make the connection (for example, fusion connection) and also to provide a reserve 65 of material for future re-connections. In addition, the unrelated express fibers, which are stored in the closure device, may be cut and bonded in the future. "Free fiber optics" are preferably contained in tubes, and these tubes are sometimes referred to as "free tubes" (hence the expression "free fibers").

In one of the embodiments of the invention, only one of the two covers 70 is adapted to play the role of tray-holder for connections, in order to provide optical fiber connections.

Preferably, in this embodiment, the other lid is adapted to be a support for storing the free fiber portions. This lid is adapted to be a storage tray, being provided with some means of retaining the free fibers, for example 75 in the form of ears or projecting elements.

In another embodiment, both the first and second lids are adapted to be support trays for connections, with the role of providing fiber optic connections. For this purpose, both covers are provided with means for retaining the connections. In this embodiment, it is desirable to provide an additional fiber storage tray, for storing any length of free fiber optics, the additional tray being provided with means for retaining the free fibers.

»In addition to the provision of means for retaining the connections (being thus adapted to function as a tray for connections), the first and / or the second cover may also be provided with means for retaining the free fibers. (and in this way being 85 adapted to work as a storage tray). Conveniently, for example, a lid that is adapted to be both a tray for storage and a storage tray, can support any additional length of the connected fibers, while keeping the fibers unrelated (sometimes known as "express" fibers ) can be made either by the other lid or by a separate separate storage tray. 90

The covers are hollow inside and have conjugated surfaces that can be sealed against each other around fiber optic cables. Preferably, the two caps are generally similar in shape. In a preferred embodiment, each of the two covers is generally elongated, having most of the practically flat surface and side walls starting inward from the elongated edges of the large, flat surface. In the preferred 95 embodiments, each cap is hinged at one or both ends. This configuration can increase the quality of the cable sealing.

RO 118986 Β1

The means for retaining the connections inside the covers, with the role of making them the trays for the connections, can take any convenient form. The appropriate means will be apparent to the skilled person. In one of the embodiments, according to the invention, the lid is provided with two ribs facing upwards relative to the surface of the lid, practically parallel to each other, on at least part of the length. An elastic material, such as foam, may be provided between the upwardly oriented ribs, in which, during use, the fiber connections may be placed in order to secure them in position. The elastic material is thus positioned in a channel formed between the ribs. The separation of the upwardly oriented ribs and the thickness of the foam, or other elastic material, are chosen according to the size of the connections, so that the elastic material must be slightly compressed for inserting the connections. This eases the load of the installer when inserting the fittings, while simultaneously holding them firmly in position throughout the working life of the equipment. Parallel nerves facing upwards can be curved or straight, depending on what is desired for optimal connections. One of the parallel ribs facing upwards may be secured by one side of the lid wall. Each lid, which is adapted to be used as a tray for joints, may be provided with one or more pairs of parallel ribs facing upward to receive the fiber connections.

In cases where one or both lids are adapted to function as a storage tray, or if an additional storage tray is provided, the storage function is preferably provided by the provision of prominent ears or elements, so arranged. so he can support the free fibers. The ears or protruding elements are means of retaining the free fibers. The protruding ears or elements are preferably arranged so as to support free fiber in the form of loops. This diminishes the possibility of fiber damage or signal attenuation, both of which may result from excessive bending of the fibers.

The covers can be assembled with each other by any suitable means. For the convenience of handling, the lids are preferably pivotally mounted relative to each other, for example hinged. In the case of the preferred embodiment, with the caps generally elongated, they are preferably pivotally connected along a longitudinal edge. A pivoting connection means that the two covers are held together, and for this reason are handled as a single piece, but they allow full opening of the covers, for example on a flat surface, allowing easy access to the tray area for connections and to that of the storage trays.

If a separate storage tray is provided in addition to the two covers, the separate storage tray is preferably pivotally mounted, for example hinged, by the two covers. The pivoting linkage is preferably made so that the two covers can be placed on a practically flat surface, and the additional storage tray is protruding up (or down) against it. The additional storage tray is preferably able to remain in a position virtually perpendicular to the two lids placed. This makes it easier for the installer to access and work inside each lid, as well as to the additional storage tray. This pivoting construction is preferably made by means of a connecting plate on which the storage tray is mounted. The storage tray is provided, preferably, with both pivoting and sliding means. The pivoting means allow the storage tray to pivot against each lid, and the sliding means allow the storage plate to slide transversely to each lid, at least when the storage tray has been pivoted in an orientation in which it is practically parallel to said lid. . The sliding means allows the two caps to move towards each other, to close the assembly. The design of the middle, which allows both pivoting and sliding, leads to the creation of a closure device for connections, compact and easy to handle because it is made of a single piece, and also provides total and easy access to the areas where it is Find out the connection tray and storage tray.

RO 118986 Β1

The preferred pivoting construction (for example a joint) ensures the assembly of the 150 of preferred shape elongated along one edge. the joint along the other edge can be obtained by any suitable, known means. For example, the covers may be provided with protruding conjugate elements, which spring into one another. Preferably, the coupling means are so constructed as to allow easy re-opening for further intervention in the closure device for the connections. 155

The closure device according to the present invention can be so constructed as to comprise any type of connection, for example a line connection, end-to-end or branching. In preferred embodiments, the cables therefore exit to one or both ends of the closure device for connections.

In addition to connecting the lids to each other, they must also be sealed 160 against each other. This can be done in several ways, as will be clearly apparent to those skilled in the art. In a preferred embodiment, according to the invention, the conjugated surfaces of the two caps have a wedge and a groove shape respectively, and are provided with a sealing gasket disposed within the wedge channel. The sealing gasket may, for example, be made of rubber, gel, a polymeric foam or a combination of these materials. In addition, it is preferable to provide a seal around the cables, in the area where they enter the closure device, which may also be rubber, gel, polymeric foam, etc. When using a gel, this is preferably a thermoplastic gel. A preferred polymeric foam is silicone rubber foam. 170

Although the two covers are preferably connected to each other, for example pivotally, for ease of handling, this joint is preferably removable. This makes it possible to provide interchangeable lids, which can be chosen depending on the assembly of the desired closing device, for the purpose of a certain operation. For example, the covers can be made so that they can be adapted to a particular type of connection, for example 175 as trays for classic in-line connections, trays for bypass connections, storage trays, etc.

The closure device according to the present invention has the advantage that it is compact and easy to use. However, it can easily be used for sealing up to 24 or more connections.

In the following, several embodiments of the invention will be described, in connection with 180 and with Figs. 1 ... 9c, in which:

- Figures 1, 2 and 3 are perspective representations of three different embodiments of the closing device, each of which is represented in the open position;

- Fig. 4 is a cross-section through the retention area of the fiber optic connection, according to plane IV - IV of each of Figs. 1 to 3; 185

- Fig. 5 represents the closed position of each of the closing devices of Figs. 1 to 3;

- Figs. 6a and 6b are schematic representations, in cross-section, of the closing device of fig. 2;

- Figs. 7a, 7b and 7c represent, schematically, cross-sections of the closure device 190 of Fig. 6, in the closed, partially open and respectively fully open position;

- Figs. 8a and 8b are partial schematic views, in perspective, of the closing device of fig. 2, representing the assembly of the component parts;

- Figs. 9a, 9b and 9c are partial, schematic representations, in perspective, of the closing device assembled in fig. 8, in the closed position, partially open and, respectively, the horn-195 open plate, corresponding to fig. 7a. 7b and 7c.

RO 118986 Β1

Referring to the drawings, FIG. 1 is a first embodiment of the closure device according to the present invention, comprising two caps 2 and 4, in the form of semi-carcasses. The covers 2 and 4 have conjugated surfaces 6, on the outline, which can be sealed against each other. The way of sealing the conjugated surfaces 6 is described below. Each lid 2 and 4 is generally elongated in shape and inside it has a large, practically flat surface (not shown in the figure) and some side walls 8 which are oriented inwards, starting from the large surface to the conjugated surfaces 6 , mentioned.

The cover 2 is provided with a pair of ribs 10, parallel, elongated, straight, and facing upwards that border a channel 12, containing an elastic foam 12. Some optical fiber connections 14 are positioned between the ribs 10 and 10 ', oriented in up, and the elastic foam 12 secures them firmly in position. The ribs 10 and 10 ', facing upwards, in combination with the elastic foam 12, represent means for retaining the connections 14 in the lid 2. The provision of the connections by the elastic foam 12 and the ribs 10 and 10' is illustrated in detail, in fig. 4. In the embodiment shown in FIG. 1, one of the upwardly oriented ribs 10 is made by a part of the side wall 8 of the lid 2.

The cover 2 is also provided with some protruding ears or elements 16 and 18, which maintain the fiber portion loops 20, on the path to the connection area.

Cover 4, unlike cover 2, is not provided with means for retaining the connections 14. Instead, it is provided with protruding elements 22, which act as means of retaining the free fibers. The protruding members 22 support loops of additional portions of optical fibers which are advantageously stored inside the closure device for fittings for further rearrangements. The additional fiber portions of the interconnected fibers may be supported in the cover 4 and / or together with additional portions of the unrelated fibers, or so-called "express" fibers.

Fig. 1 shows a line connection, with two cables 24, of optical fibers that enter the closure device on each of the two ends. The cover 4 is provided with a sealing material 26, for example a gel or a rubber for sealing around the cables 24. The sealing material 26 contains channels for receiving the cables 24. In addition, the retaining straps 28 are arranged around the cables. 24, to retain the cables 24 and secure them to the cover of the closing device. The retaining flanges 28 also serve to hold the sealing material 26 in place, which is particularly useful especially when the sealing material is a gel.

Inside the closure device for the connections, the outer shell of the fiber optic cable is removed and the optical fibers are exposed along their length. In the storage area, provided in the cover 4, additional fiber loops are organized, the fibers to be connected being conducted inside the cover 2, and the connections are arranged as described above. As soon as the connection operations have been completed, the covers 2 and 4 can be brought to a position where the conjugated surfaces 6 are sealed together for closing the device. The closing device in the closed position, is further represented in fig.5.

The covers 2 and 4 are provided with joints 30, which allow the covers 2 and 4 to be opened and placed in the same plane, for convenient access.

Thus, the embodiment of FIG. 1 illustrates a device for closing the connections for an in-line connection, in which one cover 2, in the form of a semi-housing, is the tray for holding the connections 14, and the other cover 4, also in the form of a semi-housing. , is the storage tray. The storage tray is located in the same plane as the cable entry plane, which is simple to construct and avoids excessive bending of cables or optical fibers.

The device is compact and easy to use.

RO 118986 Β1

Fig. 2 represents another embodiment of the device for closing the connections, according to the invention. Identical reference signs were used to designate similar elements, compared to the device in fig.1. In this embodiment, both the covers 2 and 4 are provided with means 10 and 12 for holding the connections (not observed in the case of the cover 4), and for storing the additional free optical fiber portions, a separate storage tray 32 is provided. . As in FIG. 1, the cables 24 enter the device of 250 closure in the plane of the storage tray, which in the example in FIG. 2 is the storage tray 32, and in the example in FIG. 1 was the lid 4. The covers 2 and 4 and The storage tray 32, additionally, are connected by the joints 30, in a manner that allows the covers 2 and 4 to be placed in the same plane, while the storage tray 32 is oriented perpendicular thereto. The sections 30 are described in more detail below. In the embodiment of FIG. 2, as in 255 that of FIG. 1, a connection of two incoming cables and two outgoing cables is used.

Fig. 3 describes another embodiment of the closure device for connections, according to the invention. Again, identical reference signs were used to designate edentric elements, as compared to Figures 1 and 2. The closing device for 260 connections in Fig. 3 is intended for a bypass link, and joins fibers from a straight main cable. with those of two branch branches 36. As in the previous cases, the cover 2 works as a tray for connections. The cables enter the closure device in the plane of the cover 4. In this embodiment, the main cable 34 passes directly through the device (with bypass fibers to be connected to the bypass cables), and no additional 265 fiber loops are stored in cover 4.

Fig. 4 is a cross section according to the plane IV - IV of the previous figures, representing the means for retaining the connections. Nerves 10 and 10 *. facing upwards, they contain a layer of foam formed in a channel 12, inside which the connection 14 of fibers is inserted. 270

Fig. 5 represents the closing device of Figs. 1 to 3 in the closed position. Lids 2 and 4 are sealed against each other. The construction is very compact, although the fasteners in Figures 1 to 3 can be used to contain, for example, up to about 24 connections, or even more.

Fig. 6a and 6b represent the assembly of the component parts of the device of Fig. 2, with 275 holding the covers 2 and 4 and a separate storage tray 32. The storage tray 32 is mounted on a connecting plate 30 which has two pivot points 40. The connecting plate 30 is provided at each end with a protruding element 42, elastic which can be pushed and locked in an element 44, conjugate, located on each of the covers 2 and 4. By pushing the protruding member 42, the connecting plate 30 can be removed from the 280 locating position 30 and thereby the storage tray 32 is disassembled with respect to the covers 2 and 4. The assembly, in The mounted phase is shown in Fig. 6b. Lids 2 and 4 can pivot around points 40, relative to storage tray 32. Lids 2 and 4 can also slide in the transverse direction from storage tray 32, for example in an upward and downward direction. down in the plane of the figure. In Fig. 6b, the covers 2 and 4 are shown in the maximum position 285 away from the storage tray 32, so that the protruding members 42, from the connection plate 30, come in direct contact with the element 44 on the covers 2 and 4 .

Figs. 6a and 6b represent the same wedge and groove principle of the conjugated surfaces of the covers 2 and 4, until indicated by the reference sign 46, and the channel by the reference sign 48. A sealing cord 50, for example rubber ( for example, silicone rubber foam, or gel, or a combination thereof, is also introduced into channel 48.

RO 118986 Β1

Fig. 7a, 7b and 7c represent the assembled elements of fig. 6a and 6b in the closed position, partially open and respectively fully open. To move from the completely closed position of Fig. 7a to the fully open position of Fig. 7c, the covers 2 and 4 first slide in the transverse direction from the storage tray 32 until the protruding member 42 on the connection plate 30 reaches contact with element 44 on the covers 2 and 4. This transverse movement releases the pivot points 40 and, consequently, the covers 2 and 4 can then be pivoted around these points up to the position in fig.7c. This is the fully open position with the two covers 2 and 4 in the same plane, and the storage tray 32 oriented perpendicularly. This position allows for convenient access inside the entire device.

The fact that the connection between the covers 2 and 4 and the storage tray 32 is removable, is advantageous, as it allows different combinations of covers that can be combined to perform different functions, for example in-line, by-pass, storage connections, etc.

Fig. 8a and 8b are representations, in perspective, corresponding to Figures 6a and 6b and represent the assembly of the component elements of the closing device of fig. 2. The same reference marks have been assigned to identical component elements, and the comment figs. 6a and 6b applies directly to these figures as well.

Fig. 9a, 9b and 9c are representations, in perspective, corresponding to figs. 7a, 7b and 7c and show the assembled elements of fig. 8 in closed, partially open and respectively fully open position. Identical reference signs refer to identical elements, and the commentary on figs. 7a and 7c applies directly to these figures as well.

Claims (10)

1. Closure device for sealing and retaining fiber optic connections, comprising a first cover (2), hollow, inside and a second cover (4), also hollow inside, the covers (2 and 4) having surfaces conjugates (6) for the assembly of the closure device, characterized in that, respectively, the two caps (2 and 4) are joined by a connecting plate (30), the connecting plate (30) being able to slide relative to the first lid ( 2) and respectively with respect to the second cover (4), so as to allow the two covers (2 and 4) to be assembled in a position away from each other or in a practically closed position, the plate connection (30) being provided with two pivoting means (40), spaced apart, so as to allow the two covers (2 and 4) to pivot against each other, when in a position away from each other from the other. Closure device according to claim 1, characterized in that the connecting plate (30) only allows pivoting in the situation where the first and second covers (2 and 4) are in a position far apart from each other. Closure device according to claim 1 or 2, characterized in that the connecting plate (30) is removably assembled with each of the two covers (2 and 4). Locking device according to claim 1.2 or 3, characterized in that a storage tray (32) is mounted on the connection plate (30). 5. Closure device according to claim 4, characterized in that the storage tray (32) is provided with means for retaining the free fibers. 6. Closure device according to any one of the preceding claims, characterized in that at least one of the covers (2 and 4), respectively, is provided with means for retaining connections (10, 10 'and 12) of the connections, for retaining the connections (14) of optical fibers. RO 118986 Β1 340 Closure device according to claim 6, characterized in that only one of the covers (2 or 4) is provided with retaining means (10.10 'and 12) of the connections, and the other cover is provided with retaining means ( 22) for storing free fiber portions. 8. Closure device according to claims 1 ... 6, characterized in that both the first cover (2) and the second cover (4) are provided with retaining means (10.10 'and 12). for securing the optical fiber connections (14). Closing device according to any one of claims 6 to 8, characterized in that the retaining means (10.10 'and 12) of the connections comprise two ribs (10 and 10') practically parallel and facing up and preferably, an elastic material (12) between them, the optical fiber connections (14) being positioned, in use, inside the elastic material (12). Closure device according to any one of the preceding claims, characterized in that the connecting plate (30) is provided at each end with a protruding elastic member (42) which can be pushed and lockable within an element ( 44), conjugated, provided on each lid (2 and 4).