Abstract:
A compact diffusion device for optical fiber ribbons allows individual connection of all fibers on the net side with those of the apparatus side by means of a semiconnector MT4 and four semiconnectors SC-2. In this manner, one optical fiber ribbon is divided into four single fibers.

Description:
BACKGROUND OF THE INVENTION 
     The present invention concerns a diffusing device with extractable semiconnectors, integrated in a plastic card, for facilitating the termination of optical fiber ribbon cables. 
     At present, diffusors are known for central exchangers which divide a ribbon of four optical fibers, coming from the net side, into single fibers abutting to connectors SC-2. These diffusors are extremely expensive due to the complex realization process, and furthermore, they are not compact. 
     A card provided for the same purpose is also known, containing rigidly fixed semiconnectors, which are available only if the card is completely disassembled. Thus, this card system has an evident negative aspect in use. 
     SUMMARY OF THE INVENTION 
     It is the aim of the present invention to provide a compact diffusor device for the termination of fiber optic ribbon cables, wherein the device is functional, simple and cheap. 
     The aim set forth is reached by means of the diffusor device according to the present invention, comprising extractable semiconnectors which are integrated in a plastic card, for individually connecting all fibers on the net side with those on the apparatus side by means of a semiconnector MT4 and four semiconnectors SC-2. In this manner, one optical fiber ribbon is divided into four independent optical fibers. 
     The main advantages of the compact diffusor device according to the present invention are: 
     low cost; 
     ease of installation in all existing frames and exchangers, with negligible modifications; 
     small size and compactness; 
     ease of eventual replacement, but, most of all, ease of maintenance, because it is possible to perform any cleaning operations on all semiconnectors and sleeves outside the card, by means of simply unscrewing two screws, without particular care or special procedures. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention is described in more detail hereinbelow according to the enclosed drawings in which a preferred embodiment is shown. 
     FIGS. 1 and 2, respectively, show the plant and the lateral views of a diffusor device with extractable semiconnectors, integrated in a plastic card, for the termination of fiber optic ribbon cables. 
     FIG. 3 shows the view A--A and a partial cross section. 
     FIGS. 4, 5 and 7, respectively, show the plant views of the three levels L1, L2 and L3. 
     FIGS. 6 and 8, respectively, show sections B--B and C--C. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The figures show a diffusor device with extractable semiconnectors, integrated in a plastic card, for the termination of fiber optic ribbon cables. The diffusor device includes: 
     a body 1 for containing, at a first level, the extension of the fiber optic ribbon, an optical coupler and an area for dividing the ribbon into the single fibers; 
     a body 2 for an upper closing; 
     a separator 3 for the second level; 
     a separator 4 for the third level; 
     a four-way sleeve 5 for the connectors SC-2; 
     a small block 6 for blocking the four-way sleeve 5; 
     a screw 7 for blocking the small block 6; 
     a semiconnector 8 SC-2; 
     a connector 9 MT4, of the push-on type; 
     a support 10 for a connector 9 MT4 push-on; 
     a blocking system 11 for the reinforced small tubes for the protection of the optical fibers; 
     a door 12 for access to the connector 9 MT4 push-on; 
     an indicator section 13; 
     a system 14 for containing the optical fiber ribbon; 
     a system 15 for fixing the card; 
     a ribbon 16 with four optical fibers (Ribbon); 
     an optical coupler 17; 
     a single fiber 18; and 
     a single fiber 19 protected by a small reinforced tube. 
     Relating now to the details shown in the figures, the diffusing device according to the present invention includes a card which connects with a semiconnector 9 MT4, of the push-on type. The card includes four semiconnectors 8, SC-2, which connect with a four-way sleeve 5, and the card may further contain an MT or fusion optical coupler 17. An additional four semiconnectors SC-2 with a corresponding four-way sleeve may be provided at the other side of the card, as shown in FIGS. 4 and 5. 
     The device according to the present invention allows a very easy extraction of the optical semiconnectors 8 from the card for cleaning thereof before the connecting phase. Access to the semiconnectors 8 is accomplished by opening the blocking system consisting of a restriction element 6 which fixes sleeve 5 to the base of the card by means of screws 7 of the kind which may be manually extracted or which may be extracted by means of a screw-driver. 
     A main feature of the device according to the present invention consists in the system 11 for blocking the reinforced small tubes for the protection of the optical fibers. This blocking system 11 will carry longitudinal stresses during the phase of traction of the semiconnectors 8. 
     With respect to the structure of the device according to the present invention: 
     in the first level L1, all the housings are provided for the whole extension of the ribbon 16 and the single fibers 18 and 19, as shown in FIG. 4; 
     in the second level L2, as shown in FIGS. 5 and 6, the fibers are protected by the small separating tube 3, and the separating tube 3 provides a sliding plane in the phase of extracting the semiconnectors SC-2; on the same level L2, a shape structure 23 is provided for allowing the maximum extension of semiconnectors C1 on the apparatus side, while still assuring the minimum curving radius; and 
     in the third level L3, as shown in FIGS. 7 and 8, the semiconnectors C2 of the measuring side and net control are positioned in a way similar to the precedent level L2. 
     The device according to the present invention has such a structure that in all of the passages, the minimum curving radius of the optical fibers is assured in the card for the optical fibers in a measure higher than required. From inlet A1, the ribbon 16 will be wound twice around the round groove 21 and enters into the optical coupler 17 from which two fibers get out. These fibers, in turn, are wound twice around the second circular groove 22 from which they get out, and, after a further turn around groove 21, reach the system 11 for blocking the reinforced small tubes 19 included with the system 11. The system 11 and small reinforced tubes 19 provide for the protection of the fibers from this point until they reach the end of the connection at semiconnectors SC-2 8. 
     In a possible variant, the device according to the present invention provides that the fiber optic ribbon 16 will be connected at the outlet from the circular groove 21, by means of a multiple connector MT4, instead of the mentioned optical coupler 17, from which one single ribbon is coming out, which in turn, runs twice through the groove 22 and once through groove 21. In this phase, the four optical fibers are parted from one another. Further, the four fibers of the ribbon 16 are introduced into the blocking system 11 as already described. In this case, the card has an inlet consisting of, instead of connector 9, a protection tube containing the fiber ribbon 16, and the apparatus side will have only one end having four semiconnectors SC-2. 
     In a further variant, the device according to the present invention provides the inlet directly from the net side, for the optical fiber ribbon, thus, the ribbon is connected to the diffusor by means of a multiple connector MT4, or by means of a fusion joint.