FR2561788A1 - Cassettes for optical fibres and connection box using such cassettes - Google Patents

Abstract

The connection box uses at least one cassette, which consists of a fixed part and at least one rotationally moving part, the fixed part comprising at least one circular half-box 3 and the rotating part comprising a cover 4 which can pivot on the half-box 3. An internal circular wall 40 inside the cassette is perpendicular to the bottom of the box and to the plane of the cover and, with the outer edge 30 of the half-box, forms an annular channel. Such a cassette enables optical fibres to be introduced through slits 11 and wound for several turns around the wall 40 before being connected. A set of these cassettes can be used in one connection box.

Description

 The present invention relates to cassettes for optical fibers and connection boxes using such cassettes to allow easy continuity of the optical guides between two sections of a line.

 This kind of device finds application in installations in an industrial environment, telecommunication lines installed or not on power transmission lines, broadband distribution networks or video communications.

In the prior art, the connection box has the function of
- Make the mechanical connection between the upstream cable section and / or the downstream cable sections, this mechanical connection being made using the cable reinforcement element and the outer sheath;
ensure tightness to the right of the connection box, this tightness being achieved by a suitable device such as a cable gland, heat-shrinkable cap, etc ...;
- serve as a store for coiling a few turns of optical fibers, bare or protected by a second coating on either side of the connection, the length of fiber generally stored being twisted by a few decimetres and making it possible to be able to redo the splices;
- maintain the elements contained in the connection box - namely the fiber turns, the connection devices, the fiber to fiber welds or the connectors in the event of a removable connection;
- protect the elements contained in the connection box while respecting a minimum radius of curvature, so as not to affect the transmission characteristics and the lifetimes of the fibers.

 The connection boxes developed to date particularly or completely satisfy the above functions. By canter, none of these boxes offers easy access to the fibers, to make the connection first and then to allow a new subsequent intervention.

 The object of the present invention is to make a cassette for optical fibers which makes it possible to easily wrap fibers on this cassette and to make connections between fibers of different cables while minimizing manual interventions and by providing lengths of fibers in reserve to allow subsequent interventions. .

 Indeed, none of the devices known to date provides easy accessibility at the level of each fiber, to allow connection to be made without the aid of specific equipment and to allow any subsequent intervention at the level of each circuit. constituted by d-them fibers plus a connection, either to remake a connection which would have deteriorated, or to proceed to a change of circuit using a removable connection.

 A second object of the invention is to use at least one cassette to make a connection box.

 According to the invention the first object is achieved by the fact that the fiber cassette comprises means for coiling one or more turns of an incoming optical fiber and an outgoing optical fiber in at least one annular groove and means for connecting these fibers together.

 According to another characteristic of the invention, the means for coiling the fibers comprise a cassette constituted by a fixed element and at least one element movable in rotation, the fixed element comprising at least one half-casing and the movable element being constituted a pivotally mounted cover on the half-housing and provided inside an internal circular wall perpendicular to the bottom of the housing and to the plane of the cover to constitute with the external edge of the half-housing an annular groove.

 According to another characteristic of the invention, the means for coiling the fibers consist of two housings arranged longitudinally in a half bolt on either side of a connection box placed in a third housing arranged tangentially with respect to the first two. housings and in the extension of the axes of the cables, and a movable element mounted to pivot in each housing and provided inside a wall perpendicular to the plane of the cover to form an annular groove with the edge of the housing.

 According to another characteristic of the invention, the means for coiling the fibers consist of a plate in which an annular groove is formed on each face, each annular groove opening out by a groove on one side on the edge of which is mounted a connection, and by two discs mounted pivoting on each side so as to cover each groove.

 According to another characteristic of the invention, the means for coiling the fibers are constituted by a fixed element comprising on each face an annular groove and shaped so that the annular groove on one face is inside the internal circumference defining the second annular groove-and fitted into the thickness of this circumference; and by two discs mounted pivoting on each side.

 According to another characteristic of the invention, the mobile element comprises a fiber driving slot and the fixed element comprises at least one. slot or opening for introducing at least one fiber, the slot or opening being arranged tangentially.

 According to another characteristic of the invention, the element; fixed consists of two half-cases joined by their bottom and two mobile elements in rotation each consist of a cover, provided with a drive slot and a circular internal wall perpendicular to the surface of the cover.

 - According to another characteristic of the invention, each fixed element comprises a slot or an introduction opening arranged tangentially with respect to the direction of arrival of the fibers and the bottom of the fixed element comprises a notch provided with a housing intended to receive a connection box.

 According to another characteristic of the invention, the fixed element comprises a notch and a housing allowing the introduction of a connection box.

 According to another characteristic of the invention, the movable element comprises a notch disposed symmetrically with respect to the diameter passing through the drive slot.

 According to another characteristic of the invention, the cassette comprises a cover mounted by appropriate means on each movable element to close the notch of the movable element and of the fixed element.

 According to the invention the second object is achieved by the fact that the connection box uses at least one cassette allowing the coiling on at least one turn of two ends of optical fibers to be connected together, at least one housing receiving this cassette and means for securing one end of each fiber optic cable to each opposite edge of the box so that the axis of the cables is disposed tangentially with respect to the cassette.

 According to another characteristic of the invention, the housing (s) receiving the cassette (s) are arranged in a plane containing the axis of the cables or in planes parallel to this first plane.

 According to another characteristic of the invention the housing (s) receiving the cassette (s) are arranged in a plane perpendicular to the axis of the cables.

Other characteristics and advantages of the present invention will appear more clearly on reading the following description made with reference to the accompanying drawings in which
- Figure 1A shows a top view of a cassette;
- Figure 1B shows a left view in section along BB of the cassette;
- Figure 1C shows a sectional view along AA of the cassette;
- Figure 2A shows a top view of a second embodiment of a cassette with separate coiling;
- Figure 2B shows a left sectional view of the cassette according to the second embodiment;
- the. Figure 2C shows a sectional view along
AA of the cassette according to the second mode of execution; ;
- Figure 3 shows a third embodiment of a cassette;
- Figure 4 shows a fourth embodiment of a cassette;
- Figure 48 shows a sectional view along
AA of the cassette according to the fourth embodiment;
- Figure 5 shows a side sectional view of a
fifth embodiment of the cassette;
- Figure 6 shows a connection box using coils according to the embodiments of Figures 1 or 2;
Figures 1 mpntrent a cassette which contains the turns of two fibers 1 and 2 penetrating through the slots ll- (Figure 1C) and coiled around the inner wall 40 of the cover 4.A half-housing 3 has an outer circular wall 30 and an internal circular wall 3-1 arranged so as to constitute with the wall 40 of the cover a pivot axis for the latter. The cover includes, as can be seen in FIG. 1A, a slot 7 which, after having introduced the fiber into the slot
It comes to wedge it in the slot 7, then by rotation of this cover to wind the fiber 1 on the inner barrel 40. When we have made for example two and a half turns we return to '' a half turn back, and the turns are placed on an intermediate diameter between the diameter of the barrel 40 and the outer diameter constituted by the outer wall of the half-housing 3C. Finally, the cover has opposite the slot 7 a notch 41 and the half-housing has, opposite the insertion slots ll, a notch 32. This notch 32 and the notch 41 allow the introduction into a housing 33 provided for this purpose, in the central part of the - half-housing of a system or connection box 6, shown in FIG. 1. It is obvious that the blank 40 of the cover has, opposite the slot 7, a window 42, not shown, of appropriate size and corresponding to the housing 33 and allowing, on the one hand, the establishment of the conn system exion 6 and on the other hand, to immobilize in rotation the cover once the connection system is in place. The notches 41 and 32, once the connection system is in place, are closed by a cover, not shown, whose dimensions and shape are adapted to complement the shape of the coil. As can be seen in FIG. 1A, the housing 33 comprises elastic means 34-35 constituted by elastic tabs which make it possible to maintain the connection system 6 in its housing.

 In operation, a turn 1 is introduced into the slot 11 of the half-housing then it is passed through the slot 7 of the cover, it is immobilized and it is rotated so as to wind several turns around the drum 40 as represented by the reference 8. When, for example, two and a half turns have been made around the drum 40, we go back half a turn backwards so that the turns are placed on an intermediate diameter and the junction is made from the end of the fiber 1 with the connection system 6. Then, a second fiber 2 is introduced through the second slot 11 arranged symmetrically with respect to the axis of symmetry BB, this fiber is placed in the slot 7 and we drive the slit in rotation over several turns, then perform a half-turn backwards so as to place all of the turns on an intermediate diameter and the end of this fiber 2 is connected in the connection system 6.

Once the connection has been made, place the connection box 6 in its housing 33 and close with the cover 5, not shown. Two fibers wound in opposite directions are thus obtained, the ends of which are connected.

Given the winding diameter of the fibers, it is easy to understand that it has been very easy to prepare the fiber ends, place these ends in any specific supports, then for
make the connection. Furthermore, taking into account the coiling of the fibers
the connection can obviously be redone by reducing for example the
number of turns of a unit. In addition, each fiber, in its box
can be placed on a diameter between the minimum diameter
and the maximum diameter of this housing; so it's possible to either intro
reduce the length of excess fiber in the housing,
pull out a certain length without unwinding or intervention
on the connector; for 4 turns, the total travel length is
equal to ntkD-d); this clearance allows the displacement of the cassette, by
example, to put it in or out of its junction box.

Finally, it will be noted that the twist which is created on the fiber when it is wound around the blank 40 of the cover 4 is released gradually, when the free end of the fiber leaves through the window 32.

 FIGS. 2 represent a second embodiment of a cassette having a central part constituted by two half-cases joined by their bottom 3 and having opposite external edges 301, 302, two internal circular walls on opposite faces 311, 312 delimiting a central zone which can for example be full as shown in Figure 2C but which can just as easily be empty as shown in Figure 28, provided that it has the necessary walls so as to constitute-housing 33 for the system of connection as in the execution mode of figure 1.

A slot 111 made in the upper half-housing, to the left of the axis of symmetry BB and a slot 112 made in the lower half-housing, to the right of the axis of symmetry BB. An upper cover 41 and a lower cover 42, each provided with a circular internal wall 410, 420. It will be noted that in this case each cover has a slot 7 but on the other hand does not have a notch 41 as in FIG. 1. The central part of the coil 3 comprises, as can be seen in FIG. 28, a notch 32 allowing access to the housing 33 which will receive the connection system 6. This notch 32 is limited to an angular sector sufficient to allow the introduction of the connection system 6. The embodiment. in Figure 2 used to separate the coils of the fibers.

 The assembly optionally includes a cover 5, not shown, consisting of a portion of circular ribbon closing this notch 32 and fixing on the cassette by any appropriate means such as for example snap-fastening.

 It is quite obvious that in the two embodiments shown, the walls 31, 311, 312 can possibly be eliminated since their essential function is to constitute a pivoting means and replaced by a central pivoting axis. It will then suffice to modify the housing of the connection system appropriately.

 As previously for FIG. 1, in the embodiment of FIG. 2, the circular walls; 403, 404 comprise at least one window opposite the slot 7 allowing the passage of the connection system 6.

However, if the thickness of the bottom 3 is sufficient and at least equal to that of the connection system, it is not necessary to provide the above windows
FIG. 3 represents a third embodiment of a cassette but in which the connection system 6 is located in the extension of the axis of the cables 1, 2. In this cassette a half-housing 9 has been arranged longitudinally spaced apart, two housings 97, 96, placed so that the axis of the incoming cable 1 and the outgoing cable 2 is disposed substantially tangentially to the outer circumference of the two housings.

These housings have the form of annular grooves or constitute with each associated covers 401, 402 an annular groove. es covers 401, 402 are pivotally mounted, each provided with a drive slot 7. This cassette 9 has a third housing 95 for receiving the connection system 6 once the ends of cables 1 and 2 have been connected to the connection system 6. As can be seen in FIG. 3, the cable 1, which is introduced through a first cassette groove llA, makes a certain number of turns inside the housing 97 and exits through the second groove llB .Cable 2 is also introduced through a first groove 11C, describes a certain number of turns inside the housing 96 and exits through the second groove 11D from this second housing 96 to join the connection system. Cables 1 and 2 are fixed to the connection box by a suitable device 93.

 Figures 4 show a fourth embodiment of the cassette in which a plate 9 is provided on each side with an annular groove or groove 97, 96 which opens on one side or edge 98 supporting the connection system 6 by grooves or grooves 970, 960 ending tangentially to the respective annular groove 97, 96.

 As in the other versions, the cassette comprises slots 11 for introducing the fibers shown in FIG. 48. Obviously the annular grooves are closed by covers 401, 402 mounted pivotally and each provided with a drive slot 7.

 FIG. 5 represents a fifth embodiment of the cassette in which the fixed element 9 has an S-shaped section, constituting the grooves 96 and 95.

These grooves are closed by covers 401, 402 pivotally mounted and each provided with drive slot 7, not shown.

 Figure 6 shows a junction box using cassettes which can be of the type of Figure 1 or of Figure 2. As can be seen in Figure 6 a plurality of cassettes 3, 4 are stacked in a cylindrical housing 90 of the body of the box 9-.

The multi-fiber cables 1 and 2 are fixed to the connection box 9 by an appropriate device 93. The axis of the cables is tangent to the cylindrical recess 90 of the body 9.

This cylinder 90 serves as a housing for the cassettes 3, 4. A cavity 91 allows the fibers of the cable to be taken out with a large radius of curvature to avoid constraining them before their introduction and their placement in the cassettes. The fibers of the same circuit are wound in the cassette, as explained above, then connected.

The operations are carried out when the cassette is located outside of the connection box 9. -When the connections are made the cassettes are stacked in the cylindrical housing 90. The cassettes are held together and in the housing 90 by means exerting lateral pressure, means which are not shown.

The entire device is sealed either by a seal 92 placed between the upper cassette and the cylindrical wall 90, or by a sealed cover, not shown, closing the box 9.

 The cassette system of FIG. 1 has the advantage of being more compact in size, while the system of FIGS. 2, 3, 4, 5 is of larger dimension but has another advantage which is to be able to separate the paths. of the two fibers.

 It is quite obvious that in certain embodiments the internal wall of the groove on which the fibers are coiled consists of a part attached to the cover and therefore movable, while in other embodiments it consists by the fixed element and consequently the fiber slides along this wall.

 Other modifications within the reach of ordinary skill in the art are also part of the invention.

Claims (14)

 1 - Cassette for optical fibers, characterized in that it comprises means 3 to 4; 9-4 for coiling one or more turns of an incoming optical fiber 1 and a starting optical fiber 2, in at least one annular groove 95-96 and means 6 for connecting these fibers together.  2 - Cassette according to claim 1, - characterized in that the means for coiling the fibers comprise a cassette-constituted by a fixed element and at least one element movable in rotation, the fixed element consisting of at least a half circular housing 3 and the mobile endowing element consisting of a cover 4 pivotally mounted on the half-housing and provided inside a circular internal wall 40 perpendicular to the bottom of the housing and to the plane of the cover to constitute with the edge external 30 of the half-housing an annular groove.  3 - Cassette according to claim 1, characterized in that the means for coiling the fibers consist of two housings 96-97 arranged longitudinally in a half-box 9 on either side of a connection box 6 placed in a third housing 95 disposed tangentially with respect to the first two housings 96 and 97 and in the extension of the axes of the cables 1, 2, and a mobile element 401, 402 pivotally mounted in each housing and provided inside a wall perpendicular to the plane of the cover to form an annular groove with the edge of the housing.  4 - Cassette according to claim 1, characterized in that the means for coiling the fibers consist of a plate 9 in which an annular groove 96-97 has been practiced on each face, each annular groove opening out with a groove 960-970 on the edge 98 of the plate on which is mounted a connection device 6, and by two discs 401, 402 mounted pivoting on each face so as to cover each groove.  5 - Cassette according to claim 1, characterized in that the means for coiling the fibr-es consist of a fixed element 9, having on each face an annular groove 96, 95 and having an S-shaped section so that the annular groove 95 on one side is inside the internal circumference defining the second annual groove 96 and carried in the thickness of this second groove, and by two discs 401, 402 mounted pivotally on each face.  6 - Cassette according to one of the preceding claims, characterized in that it comprises on the movable element a slot 7 for driving the fibers and on the fixed element at least one slot or opening ll for introducing at least one fiber, the slot or opening 11 being arranged tangentially with respect to the direction of arrival of the fiber.  7 - Cassette according to one of the preceding claims, characterized in that the fixed element is constituted by two half-cases joined by their bottom and that it comprises two movable elements in rotation each constituted by a cover 401, 402 provided with 'a drive slot 7 and a circular internal wall 403, 404.  8 - Cassette according to claim 7, characterized in that each half-housing has a slot or opening 111, 112 disposed tangentially with respect to the direction of arrival of the fibers, and that the bottom of the fixed element has a notch 32 provided with a housing 33 intended to receive a connection box 5.  9 - Cassette according to claim 6 or 7, characterized in that the fixed element comprises a notch 32 and a housing 33 allowing the introduction of a connection box 6.  10 - Cassette according to claim B or 9, characterized in that the movable element comprises a notch 41 arranged symmetrically with respect to the diameter passing through the drive slot 7.  11 - Cassette according to claim 10, characterized in that a cover 5 mounted by appropriate means on each movable member live close the notch of the movable member and the fixed member  12 - Junction box using at least one cassette according to one of the preceding claims, comprising at least one housing 90 receiving at least one cassette 3, 4 allowing the coiling on at least one turn of two ends of optical fibers to connect-together, and means 93 for securing one end of each fiber optic cable 1, 2 to each opposite edge of the box and tangentially to the circumference of the cassette.  13 - Junction box according to claim 12, characterized in that the housing (s) receiving the cassette (s) are arranged in a plane containing the axis of the cables or in planes parallel to this first plane.  14 - Junction box according to claim 12, characterized in that the housing hems receiving the or les- cassettes are arranged in a plane perpendicular to the axis of the cables.