MX2013006664A - Improvements in access and connection terminal devices of fiber optic networks. - Google Patents

Abstract

Improvements in cabinets and splice devices and terminals of access and connection of fiber optic networks, which are characterized by the modular formation of access and distribution terminal boxes, which include a support body, a lower tray and an upper tray, which are independent one from each other, and installed one inside and/or above the other, which can be uncoupled with their respective inner connections.

Description

IMPROVEMENTS IN CABINETS AND ACCESS AND TERMINAL DEVICES CONNECTION OF OPTICAL FIBER NETWORKS DESCRIPTION The present invention introduces improvements in the design and consequent functionality of the terminal boxes for access, splicing and distribution of cables in fiber optic networks, as well as in the cabinets and access devices, in the section in which they connect with the final subscriber .

Such modifications, which involve both relevant novelty and inventive activity, have been conceived in order to facilitate the installation and connectivity of fiber optic networks -particularly in the section in which they are connected to the subscriber or user- as well as its subsequent operation and maintenance in the so-called "terminal boxes for distribution and access to the client".

BACKGROUND OF THE INVENTION The optical fibers seem to have all the necessary properties to allow the transmission of signals of very high speed and large bandwidth, and also do it at a great distance without significant losses due to attenuation.

However, they are also extremely delicate, and their diameter (of the order of 250 microns) does not exceed that of very fine hair. Its flexibility is deceptive at the time of bending, can easily become entangled and even cut, and by their characteristics begin to lose their properties of transmission of light below a certain radius of curvature. Once the optical fibers are "bare" for their connection, in that state they do not have great resistance to traction, much less to the cut.

When the optical fibers are removed from the buffer tubes that protect them inside the multi-fiber cable. they must be treated with extreme care. For this reason, "ad hoc boxes" have been designed for the splicing tasks with a high degree of mechanical protection, which is intended to be adequate by means of aerial or underground installation.

It is no less important to keep in mind that although the fibers are made of glass, the surface coating that gives it some of its characteristics and properties is made with other materials that degrade with moisture. Therefore, in case of getting wet it can both increase its attenuation and become extremely fragile, to the point that before any attempt to flex the fiber can be cut. For this reason, it is necessary to provide for the protection of the fibers from the weather, avoiding mainly their contact with humidity.

Also the change of planes inside the boxes, the torsion or bending of the optical fibers attenuated against their useful life. It is desirable to prevent terminal boxes from providing airtight seals -mainly in overhead networks, installed outdoors-, since in such situations they are usually subjected to severe changes in temperature between day and night, with the effect of secure condensation. humidity inside.

The folds and movements of the fibers become "fatigue" (or "stress") of materials, decreasing the optical properties of the fiber and increasing the risk of cuts or fractures, with the consequent loss of transmission.

The current models of splicing, connection and distribution products of fiber optic cables known in the market - and mainly those used in the last section of the network, which connects with the final subscriber - tend to present serious operational deficiencies due to the aforementioned causes; mainly in the tasks of massive installation, on public roads.

To the described aspects should also be added the frequent lack of foresight of the need that telecommunications companies have (users of FO Terminal Boxes), to carry out frequent checks and measurements of the network, and very particularly to carry them out from the aforementioned FO Terminal Boxes.; both in the direction of the Central and the subscriber. Such operations are usually executed by light sources, light power meters, OTDR (Optical Time Domain Reflectometers) or other reflectometers, and in all these situations the operation necessarily involves maneuvering with such delicate materials.

In purity, the known designs of the terminal and access boxes of F.O. have conceived these as a traditional junction box, which should never be accessed again (except to install subscribers). For this reason, not only do they not foresee it, but they even promote that the input and output fibers of the optical splitters or Splitter are soldered to the fibers coming from the plant (and to those that leave them); so in case of need to perform measurements or tests of the network said fibers should be cut and then re-spliced.

For the solution of these drawbacks, some manufacturers have introduced modifications to their original design, providing connections outside or inside them. However, to access these boxes it is always necessary to move (pivot) different plastic or metal pieces, or trays that always have fibers mounted on them, and that are transferred from one to another plane of the same or other trays, always remaining connected and even interlaced between them.

In this way, when accessing the boxes, the internal connections inevitably end up moving, causing folds in the optical fibers and running the risk of entanglement and / or cutting them.

One of the basic operational needs of all telecommunications networks, then, is to have access to different points of the network to be able to make measurements -in any of the two directions of their flow- and for this it is necessary to have a " access point "to be able to" open "the network, and carry out the necessary measurements and tests.

The network connection topology also requires that in one direction the measurements should be made through the optical splitters (Splitter), which by their intrinsic characteristics introduce distortions in the light signals that affect the measurements; in particular when these are made from the side of the output fibers towards the input fiber.

Therefore, when attempting to carry out measurements, it is usually necessary to disconnect said optical splitters by means of a "by pass" thereof.

The solution of all the aforementioned shortcomings of the current designs constitute -as will be seen- the objective of the innovative modifications whose patentability is claimed, and that in the facts lay the foundations for a new generation of FIXED cable terminal boxes for access to subscribers.

BRIEF DESCRIPTION OF THE FIGURES Figure 1 is a perspective view of the box containing fiber optic cables also called "the plane" or "external volume".

Figure 2 is a perspective view of the box containing fiber optic cables with the lid open showing the complete set, appreciating the lower or inner tray.

Figure 3 is a perspective view of the box containing optical fiber cables with the lid open showing only the housing.

Figure 4 is a perspective view of the inner or lower tray or plane.

Figure 5 is a perspective view of the inner or lower tray or plane within the container box.

Figure 6 is a perspective view of the transparent flexible lid that is inside the inner or lower tray or plane.

Figure 7 is a perspective view of the upper tray or cassette.

Figure 8 is a perspective view of the transparent flexible lid of the lower region of the cassette. Figure 9 is a perspective view of the outer face of the cassette.

Figures 10 and 11 are a view of the right corner of the exterior of the cassette.

Figure 12 is a perspective view of the lower or inner tray in particular of the base of the support box, which allows to appreciate the seal block of down cables.

DETAILED DESCRIPTION OF THE INVENTION As illustrated in the attached images, the new conformation of the Fiber Optic Cable Terminal Box, for access to subscribers, has three different volumes or plans, denominated as Support Body or Container Box (Fig.l), Inferior or Interior Tray (Fig.2), and Tray Superior or Casete (Fig. 7, 8 and 9); all modular and independent, but when assembled together and one over another end up forming a single body or operating set.

Such pieces or volumes are firmly fixed to each other and can be separated again, allowing to work on or inside them independently (or modularly), without for this purpose the fibers installed inside must be moved in any way.

Likewise, the innovative design introduces the concept of "Point of Connection / Disconnection, Access and Testing" of the network, which not only achieves the result of being able to technically divide it at that point but also allows the separation of the cassette from the support box, with all the components mounted on it, and access both the cassette itself and the volume or inner (lower) plane of the Terminal Box; all without the need to move the fibers installed on them.

The "External" Plane or Volume (Fig. 3), arbitrarily called Support body (or container box), is constituted by a base (1) and a closing cover and mechanical protection (2) that pivots vertically, and whose together, when closed, it forms a "labyrinth" in the contour of the meeting between the two parts, which provides a high degree of tightness.

Such sealing assurance omits the use of rubber seals, so the box can "breathe" and thereby avoid the moisture condensation effect, affecting its components.

At the same time, the outer closing lid and the base on which it pivots on a virtual axis of its upper face, form a locking mechanism generated by the particular format of both parts, which allows the lid to be opened in different positions to operate within it.

The other interior planes are installed inside the support body, and fixed inside by means of screws and / or plastic fixing devices as appropriate, being able to do so in the field, and before or after the support body is fixed on the post or the wall, using bolts or strips.

A tray or "lower" plane (Fig. 4) constitutes the interior volume of the assembly, and consists of a tray that is mounted inside the base of the support body, fixed firmly to it by screws.

The multi-fiber cables entering / exiting the Base of the Box are mounted and fixed on it through existing holes in a "base" of the base (3), which are in turn assembled from the removable sealing elements. of moisture of the multifiber cable, and the retention elements of the central member of the multifiber cables.

The possibility of separating, assembling and disassembling the lower tray (Fig. 5) inside the box allows the same with the multi-fiber cables and with the arrangement of the loo tubes and the splicing of the fibers, so that such operations can To be done at ground level or inside the installer's vehicle, and after having completed the internal connections, the assembly can be installed again inside the base.

The lower tray described also has two clearly separated zones between each other, which allow: the first of them (4) to store, order, and tie up the gain of the protective tubes (loo tubes) of the unused fibers, which continue in the output cable; and the second (5) the accommodation and fixation of the gain of the fibers chosen for splicing, and that of the pigy cable (s) connecting to the "intermediate coupler", which will be described later.

Likewise, this element contains a "comb" (6) for supporting and retaining the spliced fiber protection sleeves, and has at that end a "ramp" (7) that serves as a protection and acts as an access guide to the upper level , for the pigtail cable (s), up to its connection (s) with the "intermediate coupler" (8) or "test point" housed at the end of said ramp.

The ramp is topped by a "window" housing for the assembly of the "intermediate coupler", which allows the connection of the connector (s) of the pigtail that has been joined with the (s) ) fiber (s) coming from the Central, with the connector coming from the input side of the Splitter.

The ramp thus described allows the coupler assembly with the pigtail connectors (the set "test point") to rise above the level of the lower tray, and enter, through the cavity provided for that purpose, the upper plane (from the same cassette), which gives the test point the easy access from the outside of the upper tray, without having to move, touch, or intervene fibers in the process, or in connection / disconnection and test operations.

On the lower tray (Fig. 5), finally, it is also solidly fixed by means of screws.

"Retaining terminal" of the cables to the subscriber, which along with the "cable guide comb" and the "seal element" of the cables down, together form a novel system of retention, guidance and sealing of the same ones (9).

The entire wiring area is protected at the end of the installation, with a flexible cover transparent (Fig. 6) (10).

The upper tray or "Casete" (Fig. 7) is the third element of the terminal box set, and its novel design allows the housing of the optical splitters (splitters), and hold them by means of elastic plastic springs (1 1), adaptable to a wide variety of sizes and models.

Likewise, it helps to order and adjust the gain of the input fiber and the output fibers of the Splitter by means of an organizer (12) suitable for this purpose, which has obstacles that prevent the fibers from being released and / or disordered during transport or manipulation, and prevents "entanglement" among themselves, thus ensuring that the radii of curvature of the fibers are greater than the minimum admissible by the regulations in force.

This cassette also provides the adequate support for the assembly of the "Output couplers" (Fig. 1 1) (18) that will make it possible to connect / disconnect the connectors of the cables down to the subscriber - on the outside of the cassette -, and the connectors of the output fibers of the Splitter (s) on the inside of the cassette, being properly housed and protected.

The entire lower area (Fig. 8) is protected at the end of the installation, with a flexible transparent cover (13).

In addition, the cassette has a "cavity" in its inner plane that allows its mounting on the lower tray, so that the ramp and the intermediate coupler access and see the outside face of the cette.

Similarly, in its external plane the cassette has an "exit opening" that provides the way out so that the connector and the input fiber of the Splitter can be removed from the cassette, allowing its connection to the intermediate coupler on the outside, without having to enter the inner body of the box.

The cassette thus described is surrounded on its outer face (Fig. 9) with a transparent pivoting cover protecting the access zone to the "test point", that of the "access opening", and to the "connector and fiber income "of the Splitter (14).

The external face of the cassette (Fig. 9) also has a sorting and fixing zone for the cables to the subscriber, which facilitates its installation inside the box, and the execution of its connections to the output couplers (15).

According to the innovative system devised, therefore, the connection and disconnection of the Splitter to / from the "intermediate coupler" (Fig. 10 and 11), the connection of test instruments to make measurements towards the side of the control unit (allowing to make a by pass of the Splitter), and the connection of the Splitter to measuring instruments to test towards the subscribers' side; all from the outside of the cassette, and without having to access the interior of the set. (16) (17) The cassette is fixed to the inner tray in four (4) points by two (2) elastic restraints (snap type), and by two (2) fasteners of the type "insert pin" (all of plastic material) ), which facilitates its assembly in a single operation and its removal from the box when necessary.

The down cables are housed and adjusted in the "retention oven" (19) -which is anticipated is fixed on the lower tray, but which is accessed from the outside of the cassette-, and then passes them through on the "guide comb" to be able to mount them on the "seal block" (20) of the descent cables.

What we have called "seal block" (20) of the cables down is mounted on the base of the support box, and is a piece of novel design, die cut with cuts cross-sections that allow to accommodate and seal the cables without the need to thread them; that is, they can be installed and dismantled without removing the seals from their housing (Fig. 12).

Once the cassette and the drop cables have been assembled, the "outer cover" is closed and firmly fixed to the base, giving the assembly great mechanical protection and sealing and protecting the entire assembly from the elements.

In the event that the primary fibers, or some other element of the terminal box, prove to be defective, or exhibit deterioration of some kind, the system also provides a secure access mode to the interior of the box (and to the fibers and other components) to facilitate its repair and / or replacement, as well as for the connection and splicing of other fibers coming from the Plant.

They also allow the replacement of connectors, couplers, optical splitters (Splitter), and / or even the multifiber line cables; including - of course - the download to the subscriber and its connectors.

By virtue of its "modular" design, in short, the system as a whole allows its assembly in stages and / or individually of each of its parts (or modules), and / or in an integral way at once, as well how to perform maintenance, and even the replacement of all its parts, always maintaining the integrity of the assembly and the protection of its components.

The terminal boxes of FO cables, for access to subscribers thus conceived, also import a new concept of the terminal point of dispersion and connection of the optical network to the subscriber, in order to achieve that the luminous signals coming from the Central through of one or more optical fibers, are "divided and multiplied" by the use of one (1) or more optical splitters (splitters), in order to "feed" at least two or more users; distributing the resulting light signals by means of connection cables to the subscriber in order to provide a point of access and testing, which allows dividing and carrying out measurements of the network on both sides thereof.

Assembly and operation: Phase 1 To proceed to install the subscriber access terminal box, prepare the multifiber input cable from which the fiber (s) to which it is desired to connect the Spliller (s) through the that the signals will be distributed to the subscribers.

Then, the primary cover of the cable is removed in order to provide a length of the protection tubes that allows to preserve always a free section ("gain"), which will be stored, ordered and fixed inside the lower tray. (Fig. 4) The multi-fiber cable is then fixed to the lower tray, by means of cable presses and retaining elements of the traction web (21) of said cable; both on the input side and on the output side, through which the rest of the fibers that have not been intervened continue, or those that eventually they will be spliced to that end.

Once the gain of the protection tubes has been ordered and fixed inside the reel (4) arranged for this purpose, one or two fibers are separated that we arbitrarily call "the chosen ones", which will be lodged in another reel (5) (of the lower tray) that allows you to store your gain, and do the same with the pigtail cables that will be spliced to allow connection to the intermediate coupler.

On one side of the reel storing the gain of the chosen fibers is the "housing and support comb" (6) of the protection sleeves of the joints that were made. Up to 6 more fibers can be spliced, since the support comb has 8 housings, for the case that for some reason it is necessary to splice the fibers of one of the protection tubes.

It is recommended that all splices be made by fusion technique, but eventually mechanical splices could also be used.

Once the splices are made, the pigtails are accommodated in the housing of the "guide ramp" (7) and are connected to the intermediate coupler (8), covering the area of arrangement of bare fibers and splicing by a flexible protective cover and transparent. (10) Once the cables are assembled, the lower part (Fig. 5 and 6) constitutes an autonomous (modular) part that can either be separated from the rest of the assembly, or can eventually be found already assembled inside the container box (Fig. 3).

If you have not done it before, you will install this tray inside the container box, with its cables already mounted on it, and it will be fixed firmly to the base of the box with screws.

Once this has been done, the sealing seals are installed on the input and output multifiber cables (22), and secured to the base of the body of the box by means of its fixing elements (Fig. 12).

Phase 2 The cassette can be factory assembled or, eventually, it can be equipped in the field, or in any other place by the contractor.

One or two splitters are fixed inside the cassette, and the gain of the input and output cables on the reels of the inner part of the cassette is ordered. The connectors mounted on the output fibers of the splitters are connected to the couplers that are housed inside the cassette, and that will then serve as a connection point and access to the service for the downlink cables to the subscribers.

A flexible and transparent protection lid (13) is inserted in the internal face of the cassette, which covers and protects the inside of the cassette, allowing to visualize the content (splitters, input and output cables and connectors mounted on the couplers). connection ") (18). In this way :: the crate can be transported and handled without risk of the fibers becoming entangled, entangled or deteriorating, and avoids the detachment of any of its components.

The connector and the input cable of the Spliller are removed through the opening of the outer face of the cassette, and are housed in their connection position, from which they will then be connected to the "intermediate adapter" that is mounted on the end of the "ramp" of the lower tray, and which is accessed from the outside of the cassette, thus forming the aforementioned "point of connection and disconnection, access and testing" (17) of the network.

Once the input connector of the Splilter has been positioned on the outside of the cassette, it will be protected by a rigid protective cap that "pivots" on the outside of the cassette (1). This cover is transparent and allows viewing from the outside both the connector and the input fiber to the Splitter, and the intermediate coupler mounted on the ramp.

Phase 3 Once prepared in the manner described, the cassette can be installed inside the box, on the lower plane, without tools, and with a single movement is firmly linked to the lower tray by plastic locks.

The input connectors to the splitters are then connected to the intermediate coupler, which had been left under the transparent hinged cover, and the box is then ready for the connection of the subscribers, and / or for carrying out tests of the network towards the side of the plant.

Phase 4 In this phase, the drop or "incoming" (fiber optic) cables are inserted into the box, which are connected to each of the corresponding "connection" connection couplers, accommodating the gain of the down cable that it is decided to keep on the reel prepared for that purpose. Each drop cable is fixed in the connection retention oven (19) and accommodated in the "exit guide comb", introducing them into the seal, without the need to thread them.

Finally, the outer lid of the terminal box is closed, and the installation is completed.

Claims (8)

CLAIMS Having sufficiently described my invention, I consider as a novelty and therefore claim as my exclusive property, what is contained in the following clauses:

1 . - Improvements in cabinets and splicing devices and access terminals and connection to fiber optic networks, characterized by the modular conformation of the Terminal distribution and customer access boxes, and their conformation by a support body, a lower tray and a cassette independent, installable ones inside and / or on the other, and uncoupling with their respective internal connections.

2. - Improvements in cabinets and splicing devices and access terminals and connection to fiber optic networks, as described in the previous claim, characterized in that its support body or container is constituted by a base and a closing cover and mechanical protection that It pivots vertically, and at its base the remaining component elements are fixed by means of screws and / or plastic fixing devices.

3. - Improvements in cabinets and splicing devices and access terminals and connection to fiber optic networks, as described in claims 1 and 2, also characterized by the provision of an inner tray on which the multi-fiber cables are mounted and fixed entering / exiting to the base of the box through holes in a socket, which has an area for storing, ordering and securing the gain of the protection tubes, and another for the pigtail cables connecting to the intermediate coupler, a support and retention comb of the spliced fiber protection sleeves, a ramp on that end that serves as protection and access guide for the pigiail cables at the upper level - up to its connection with the intermediate coupler or test point, which it is attached at its end in a housing "window" for the assembly of said intermediate coupler, which will also allow the connection with the connector of the incoming input cable of the Splitter.

4. - Improvements in cabinets and splicing devices and access terminals and connection to fiber optic networks, as described in claims 1 and 2, also characterized by the anticipation of an upper tray, or removable cassette that houses the Splitter, arranges and adjusts the gain of the input and output fibers of these by means of a suitable organizer, provides the physical support to the output couplers -assembled in such a way as to maintain protected both the internal side of the couplers, and the output connectors of the Splitter, and provides access from the outside to the couplers to allow the connection of the connectors of the connection cables-, and has an internal cavity that allows its assembly on the lower tray described in the preceding claim.

5. - Improvements of the upper tray or cassette described in the preceding claim, also characterized in that said piece has in its external plane an exit opening that provides the way out so that the connector and the input fiber of the Splitter can be extracted from the cassette -allowing its connection to the intermediate coupler on its external side, without the need to enter the inner body of the box-, a transparent protective cover of the access area to the test point, and a zone of ordering and fixing of the cables of down to the subscriber; leaving the cassette fixed to the lower tray, once mounted inside the box, by means of two elastic restraints and other two of the type insertion pin.

6. - Improvements made to the cabinets and connection devices and terminals for access and connection to fiber optic networks, described in claims 1, 2, 3 and 4, also characterized by the provision of a "guide comb" and a "block" seal "of the cables down, mounted on the base of the support box, and die cut with cross sections, so that they allow to accommodate and seal the cables without the need to thread them.

7. - Improvements in cabinets and splicing devices and terminals for access and connection to fiber optic networks, described in the previous claims, also characterized by the provision of a point of connection, disconnection and testing of the network, so that access to the same can be done from the outside of the cassette once mounted on the inner tray, allowing not only access to the fibers to the side of the plant but also allowing a bypass of the Splitters and eventually test to the side of the subscriber through them.

8. - Improvements in cabinets and splicing devices and access terminals and connection to fiber optic networks, described in the preceding claims, finally, also characterized by the forecast of a "labyrinth" formed around the container body -between the cover and the base- that provides excellent sealing to the assembly without the need for seal seals, and that allows moisture to escape from its interior, in case of subjected to high temperature gradients on the outside at its point of installation, and by the conformation of a "ratchet" device between the upper part of the base and the lid, which allows the lid to be kept open in different positions.