Classifications

• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
  • G02B6/44—Mechanical structures for providing tensile strength and external protection for fibres, e.g. optical transmission cables
  • G02B6/4439—Auxiliary devices
  • G02B6/444—Systems or boxes with surplus lengths
  • G02B6/4453—Cassettes
  • G02B6/4454—Cassettes with splices
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
  • G02B6/44—Mechanical structures for providing tensile strength and external protection for fibres, e.g. optical transmission cables
  • G02B6/4439—Auxiliary devices
  • G02B6/444—Systems or boxes with surplus lengths
  • G02B6/4452—Distribution frames
  • G02B6/44526—Panels or rackmounts covering a whole width of the frame or rack
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
  • G02B6/44—Mechanical structures for providing tensile strength and external protection for fibres, e.g. optical transmission cables
  • G02B6/4439—Auxiliary devices
  • G02B6/444—Systems or boxes with surplus lengths
  • G02B6/44528—Patch-cords; Connector arrangements in the system or in the box

Definitions

• the present invention relates to an optical fiber connection cassette for holding optical fibers in place, in particular, lengths of reserve rods, fibers separated or not from each other and connections, comprising:
• the invention also relates to a method for holding numerous optical fiber connections in place and storing them in a cassette.
• fiberglass optical cable is used below interchangeably for a fiberglass and synthetic fiber cable.
• connection cassettes which allow both technically and practically to make optical fiber connections and store the reserve lengths with order and method, reliability and convenience has increased significantly.
• the document EP-A-0342180 describes a fiber optic connection box for the installation of such a connection and a splice protection cassette. This known box did not, however, allow the reserve lengths of fiber optic rods to be wound up or stored.
• Document EP-A-0185923 discloses a support for connecting optical fibers, consisting of a wafer having a bottom, an outer wall provided with openings, an inner wall forming an outer ring and delimiting an inner ring formed by minus a central cylinder.
• the outer crown communicating with the inner crown through openings. It is used to store the reserve lengths of rods.
• the outer ring is used for the storage of optical fibers and connection devices between fibers.
• the cylinders may have lids mobile in rotation and provided ⁇ tabs to facilitate the establishment of rods at intermediate points. However, nothing is provided to wind the lengths of cable reserve on the outer ring without twisting the cables.
• the reserve length of the rod gathered in the form of a beam, is housed in the immediate vicinity of the storage plate.
• the present invention relates to a storage cassette ⁇ ui includes fixing means and equipment for accommodating up to 120 optic fiber connections and a large number of rod lengths, neatly and neatly and without twisting, and to fix them in a space-saving product.
• the storage cassette meets the most stringent requirements with regard to any aspect and over the entire path of the optic fiber cable, in particular the reserve length, the stripped optic fibers, the radius of curvature and connection.
• This object is achieved thanks to the structure of the storage cassette built around a mandrel, so that the assembly can be rotated around an imaginary axis.
• This ⁇ ui constitutes a characteristic of the invention is the fact that at least one compartment (jus ⁇ u'à four identical compartments) serves as a reel for winding the reserve lengths.
• a second type of compartment fulfills the structured guiding function of the rod, from the storage plate to the reel and the maintenance of an unused fiber.
• the third compartment is used to maintain the weld bond, the necessary reserve lengths and the extra-long reserve lengths.
• the rods are introduced and released by a lateral passage of the mandrel.
• a possibility of passage, for the fiber is formed from one side 45 to the opposite side.
• the present invention also relates to a method for holding in place and housing fiber optic fittings, including the reserve lengths which are associated therewith, according to which:
• the non-stripped cable is stripped of its sheath (in the distribution box or the underground muffle) and delivered from the tensile preload (Kevlar or steel wire) and telephone cables;
• the stripped optical cable is routed to the recess of the mandrel and the transit channels;
• the rod is stripped and continues as a simple fiber its path to the connection points with the connecting fiber;
• the fiber continues its path, along the outer edge of the storage plate, to then complete the processing of the useful reserve lengths in a space resembling the corridors of a race track;
• the reserve length of the rod is wound on the reel (s).
• FIG. 1 is a side elevational view of an optical cable partially stripped of its sheath
• FIG. 2 is a diagrammatic representation of a guided route drawing model of an optical fiber in the storage cassette
• FIG. 3 is a plan view of the storage plate and reproduces the layout model for the essential reserve length
• Figure 4 is a view similar to that of Figure 3, however, further showing the establishment of a length of optical fiber reserve
• Figure 5 is a view similar to that of Figures 3 and 4, of the storage plate showing the layout model for the connection of fibers from a single rod
• Figure 6 is a plan view of the guide level with an example of arrangement of a rod in two grooves
• FIG. 7 gives the layout model for two separate rods distributed over two grooves
• Figure 8 is a cross-sectional view of an optical fiber connection cassette according to the invention.
• an optic cable 1 comprises numerous tiny thin fibers distributed in various bundles.
• the constituent parts of the cable are a few support elements (also called rods), two signal copper wires, a central element of tensile preload and the covering sheath.
• the first form of protection is cladding, that is to say the coating of a fixer on which is applied the primary coating 18 intended to directly protect the fiber from fouling.
• the secondary coating is the protection of the optic fiber after stripping the rod 2.
• the rod 2 is a hollow sheath, in which several optical fibers are housed together, far from the wall. The rod is actually used to prevent any action on the optic fiber.
• the rod 2 is slightly deformable, without endangering the optic fiber.
• a sheath 19 must be able to face the harsh environment through which the cable is routed.
• a tensile preload is exerted using a Kevlar ( ⁇ F) or steel wire and two copper signal wires.
• the insulation and the prestress 20 make the cable heavier, which is not without consequence for transporting the cable. Only a few kilometers of cable can be transported by reel. For longer lengths, the pressure exerted on the lower layers could cause the disaggregation of the fiber core.
• any optical network is made up of cable lengths corresponding to several reels.
• the cable length portions of approximately 2 km are connected so as to form an uninterrupted whole.
• the technique of fusion welding or gluing is available.
• the installation and storage of the connection of an optical fiber, including the reserve length, takes place in a housing 5 which accommodates several adjacent compartments 7.
• the partitions which stand parallel to each other form reels for winding the reserve lengths of rods.
• the opposite faces of the external reels house the guide tracks provided with butterfly locks, the flat receptacle of the cable, the S curve at the transition point and the overhanging sheaths 9 for the fibers.
• the storage plate is mounted on the guide plate, which in turn carries the positioning tabs, both those of the compartment intended for extremely long reserve lengths and the compartment for the weld fittings, as well as those of the reserve length compartment and the protective casing for the welds.
• the storage plate always includes the marks which determine the radius of curvature of the essential reserve lengths of the fibers, an interior layout.
• the specific element of the reels lies in the fact that the width of the reels is calculated in such a way that unforeseen blocking of the rod during winding or unwinding is impossible.
• the base of the mandrel is constructed in such a way that no difference in level appears when the new layer is introduced during the winding.
• the transit channel from the base of the reel to the corresponding guide plate and then to the storage plate, guarantees a radius of curvature of 70 mm in diameter.
• the fixing of the direction for the choice of the storage plate is in the mandrel of the reel.
• the specificity of the guide plate lies in the arrangement of the grooves, ⁇ ui under the flowing radius of curvature of 70 mm in diameter, brings the rods to two opposite starting points, the incoming and outgoing directions.
• the positioning of the rods at various points is specific, at each passage at said points, and the directional reference in the absence of twist of the outgoing rod bundle, by means of the S-shaped groove on the plate. guide.
• the storage space in the guide plate for an unused fiber is also specified in concept.
• the specificity of the storage plate 13 resides in the multiplicity of possibilities of laser connections, thirty welds per level or 2 x 2 pairs of levels. Maintaining in place the length of the optical fiber under any circumstance is also specific.
• the specificity of the composition of the total assembly lies in the fact that the radius of curvature of 70 mm in diameter remains guaranteed.
• the passage of both the rod and the fiber takes place without friction by the calculation of the various recesses which converge towards each other at various levels.
• the specificity of the housing lies in the fact that the construction is developed in such a way that the rod and the fibers, as well as the fittings, remain visible at all times for inspection.
• the fibers to be used are separated and unused.
• the fibers to be used are stored in a separate elongated corridor provided for this purpose (compartment 24) by being fixed under positioning tabs 10, and extend from there, while maintaining the maximum radius of curvature directed towards the outside, to the connection point and the protective casing 30 of the weld (Figure 7).
• the protective box 30 is a block which can contain a maximum of 30 sandwich type protective elements.
• the block has 30 numbered grooves. On each side of the grooves are small terminals at a certain distance from the grooves, which provide the fiber with a straight line from the protective element over a certain distance.
• the point of passage from or to the protective housing of each fiber is indeed the most delicate point where there are the most breaks. For this reason, the distance from the protective casing to the first curve is chosen to be relatively wide.
• the layout of the guided route in the guide plate arises from the principle relating to the possibility of introducing and removing rods through a single point on the guide p Latin.
• the visual explanation of this principle can be seen in Figure 6.
• the principle of the connection of two fibers coming from a single rod is explained in figure 5.
• the reverse point of one of the incoming fibers is on the inner strip of the S-shaped path, while the other incoming fiber concerns its cylindrical shape.
• the welding process is carried out with a sophisticated device of great value. Since the cable mostly lies in the field, buried in the ground, and the welding equipment can only be brought with difficulty to the bottom of the hole, due to the costs, we will therefore bring the ends of the cables to the welding machine.
• the operator determines himself, based on his experience, the reserve length to make the connection (including any welds to be redone). If an excessive length of reserve is desired, this is stored along the outside wall of the storage plate. Spacing is maintained between the outer side of the storage plate and the weld protection box, mistletoe provides with the positioning tabs, the ideal space for an extra long reserve length (compartment 25).
• the tolerance of the play in the length of the fibers between the connection point and the transition point can be used freely:
• solder connections are fixed in the numbered receptacle (compartment 26).
• the unused fiber rests along the outer wall of the guide plate, below the cantilever studs, inclined from the inside towards the outside and down.
• the fiber optic connection cassette is constructed around a hub 14, so that the assembly rotates around an imaginary axis.
• the actual rotation takes place on the outside edge of the reel ( Figure 8).
• the reel offers the advantage of transforming the bundle of rods in the form of a loop.
• the recess in the hub ensures a passage to the bundle of rods through the heart of the guide plate 12.
• the helical transit channels 16 direct the direction to the left or to the right, in accordance with the preselected storage plate.
• the openings in the hub are constructed in such a way that when adding a reel, the openings extend the transit channel in order to guide the bundle of rods from the base of the reel to the guide plate.
• the width of the reel can be kept constant for wide rods and for narrow rods.
• the width of the reels is calculated in such a way that no jamming of the rod bundle is to be feared, for the cables marketed to date.
• the number and arrangement of storage plates, to the left and right of the reel-guide plate assembly, must be determined by the operator himself.
• a reel 29 is provided on the reel, mounted articulated and maintained under the slight constraint of a spring.
• the width of the wiper 29 corresponds to the width of the reel by which the rod is kept cloistered between the walls of the reel and the wiper 29.
• the wiper 29 also prevents lateral exit of the rod bundle. When the wiper occupies the extreme position, the pressure on the rod is distributed over the total surface of the wiper.
• the guide plate 12 is a complete and machined support, which forms the reverse of the side face of the reel.
• the left guide plate 12 is the left part of the reel.
• the right guide plate, the symmetrical image of the left guide plate 12, is the right part of the reel.
• the intermediate lateral faces of the reel are of course opposite faces.
• the guide plate 12 is intended to conduct the rod bundle in two previously formed grooves, from the entrance of the guide plate to the transition point, and to hold it in place without pressure or twisting. This applies to the two bundles of rods, the incoming and outgoing lines ( Figure 6).
• the transition receptacle at the end of the grooves must provide proof that the rods, with regard to this point, must be fixed in an orderly and reliable manner.
• the guide plate must ensure the smooth slope of the fiber, from the guide plate to the upper storage plate (s).
• the function of the guide plate is to simply keep the unused fiber away so that you can use it later.
• the guide plate serves to:
• the storage plate ensures that the radius of curvature of the fiber reserve length remains gently sloping and at least equal to the radius of 35 mm (70 mm in diameter).
• the storage plate (s) is (are) covered with a transparent cover, so that the solder connections as well as the fiber loop remain easily visible.
• a built-in winding system makes it necessary to wind up the necessary reserve length on the reel, independently of the cassette.
• the reserve length is wound on the reel, after which the winding mechanism is removed from the cassette.
• the incoming fibers can be connected to the outgoing fibers.
• Fibers from various rods on a single cable can also be joined, connected and reliably placed.
• the fibers of a single rod can even be brought towards one another and united under friction (FIG. 5).
• the loose ends can be wound at will, at the same time as the reserve lengths, simply on the same reels. In all cases, reliability remains assured from all angles, as well as with regard to the guidance, the radius of curvature and the positioning.
• the incoming and outgoing rod bundles form a quarter of a circumference, with a radius of curvature of 70 mm in diameter, from the entry point to the transition point.
• the transition point is where the rod turns into bare fiber 28.
• the rod deploys as a fan at the transition point and is stored flat under the fixing brackets.
• the scattered arrangement of rods simplifies formal recognition of color codes.
• the transition overlaps are offset from each other. In this way, it is prevented that the flat cable arrangements cross.
• the fiber is led under a constant slope towards the storage plate.
• the grooves are blocked at irregular distances by pivotable butterfly latches. Three of the seven butterfly latches cover the two grooves ( Figure 6). This allows the operator to quickly and easily carry out the following mounting steps.
• Protective elements can be added to the additional weld fittings, which allow, simultaneously, the use of other types of weld protection and / or the mixing of the diverging switches and the protective elements.
• an appropriate transparent cover is used, which ensures the positioning of the contents of the protection elements of the upper welds, while the upper storage plate ensures the protection of the protection elements. lower.
• the cassette is suitable for all types of fiber optic cable on the market, made of glass and synthetic material.

Landscapes

• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Optics & Photonics (AREA)
• Light Guides In General And Applications Therefor (AREA)
• Mechanical Coupling Of Light Guides (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=3888706

Family Applications (1)

Country Status (4)

Cited By (1)

Families Citing this family (5)

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• 1995
  • 1995-02-16 WO PCT/BE1995/000014 patent/WO1996025680A1/fr not_active Ceased
  • 1995-02-16 AU AU18019/95A patent/AU1801995A/en not_active Abandoned
  • 1995-02-16 JP JP8524532A patent/JPH11500237A/ja active Pending
  • 1995-02-16 EP EP95909591A patent/EP0842445A1/de not_active Withdrawn

Non-Patent Citations (1)

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