GB2286691A

GB2286691A - Universal connection unit for optical waveguides

Info

Publication number: GB2286691A
Application number: GB9503431A
Authority: GB
Inventors: Lothar Finzel
Original assignee: Siemens AG
Current assignee: Siemens AG
Priority date: 1994-02-22
Filing date: 1995-02-21
Publication date: 1995-08-23
Also published as: GB9503431D0; DE4405666A1

Description

-I- UNIVERSAL CONNECTION UNIT FOR OPTICAL WAVEGUIDES k 2286691 The

invention relates to a universal connection unit for optical waveguides.

Connection units are provided in optical waveguide 5 networks for connecting or branching off optical waveguide cables.

The use of a connecting sleeve serving to take up cassette blocks is known as a connection unit from German Offenlegungsschrift DE 41 26 039 Al.

Furthermore, it is known from German Offenlegungsschrift DE 41 40 701 Al to accommodate a distributor in a shaft which can likewise contain cassettes for taking up splices or couplers.

For some applications, however, these solutions are not yet optimum. For example, several splices and couplers for the connection of several users may be accommodated in one cassette. This renders difficult classifying work and repair work.

The present invention therefore seeks to provide a universal connection unit with cassettes for individual fibre splices.

According to the present invention, there is provided a universal connection unit for optical waveguides, comprising a hood-type sleeve housing, having a sleeve head through which connection cables are fed into the connection unit, and cassettes which are arranged so that they can be swung about a common axis of rotation wherein each cassette is dimensioned such that it does not occupy the entire crossectional area of the sleeve housing, the remaining crossectional area of the sleeve housing being provided for housing the connection cables and connecting cores.

The particular advantage of the universal connection unit follows from its construction. It can be fitted with a varying number of cassettes of differing height. These are formed - as required - for 1 individual fibre splices, bundle core splices, couplers, adapters for branching bundle cores out to individual fibres or for spooling up bundle cores.

The particular advantage lies in the ease of access of the individual fibre splices which are associated with one user and are arranged in a respective, separate cassette. The circle segmentshaped cassettes also still leave sufficient space in the hood-type sleeve for the accommodation of cables and connection cores. Moreover, adapters for branching bundle cores out to individual cores can further be provided on the rear wall.

Guide devices ensure that the minimum bending radii of the optical waveguides is maintained and that a problem-free deflection occurs between a horizontal and vertical course of the optical waveguide. If required, the overall height can be increased by extending the rear wall or by placement of a further cassette block. 20 It is also possible to add to the wiring rear wall in a modular manner. Prefabrication, as far as possible, of the universal connection unit, to which only the appropriate cores need to be connected in situ, is advantageous as well for ease of assembly.

For a better understanding of the present invention, and to show how it may be brought into effect, reference will now be made, by way of example, to the accompanying drawings, in which:

Figure 1 shows different application for universal connection units, Figure 2 shows the structure of a universal connection unit, Figure 3 shows a wiring example of a universal connection unit, Figure 4 shows the plan view of a universal Z A connection unit, Figure 5 shows the installation of a splice, Figure 6 shows a coupler cassette, Figure 7 shows a splice cassette, Figure 8 shows diagrammatically the extension of the universal connection unit, and Figure 9 shows an example of the wiring rear wall.

In Figure 1 the universal connection unit 1 is represented diagrammatically. Figure la shows the accommodation of cassettes 11 in a hood-type sleeve 6. The main cable 2 is guided from below into the sleeve, with a portion of the optical waveguide cores being cut up and distributed by way of couplers to branching cores. Another portion of the optical waveguide cores of the main cable is guided on uncut.

In Figure ib the sleeve is merely used to take up the spare length of an optical waveguide cable so that later there is the possibility for branching off.

According to Figure ic the sleeve is used to take up splices, with which optical waveguide cables are connected together. Figure ld, like Figure le, shows the branching out of, in each case, one optical waveguide to more optical waveguides. 25 In Figure if one portion of the optical waveguide cores is guided on, whilst another portion of the cores is branched out to several optical waveguide cores. An exemplary embodiment of the universal connection unit 1 is represented in Figure 2. Mounted on the sleeve head 4 on a securing bracket 8 there is a rear wall against which rest circle segment-like cassettes 11, 12 and 13. The main optical waveguide cable 2 is guided through a bushing 5 of the sleeve head 4 and by way of a cable holding support 28, 16, is secured in an oval. A division into different branching cores 29 is effected, for example, in the X cassettes 12, 13 and 11. The two upper cassettes 12 and 13 are provided for this purpose, which cassettes contain adapters for separating the bundle cores and couplers for branching-out purposes. The cores of the branching cable 3 are spliced with the connection cores of the couplers in the lower cassettes 11. The joining together of the individual hollow cores 22 to form bundle cores can be effected in a further cassette or in adapters 24 which are arranged on the rear side.

Deflecting plates 20 and core guides ensure that the minimum permissible bending radii for the optical waveguides are observed.

The wiring for a "branch-connection unit" is diagrammatically represented in Figure 3. A guide channel VI is provided for the uncut and cut bundle cores of the main cable HK into which guide channel VI the cores are guided in a loop. The optical waveguides obtained from the main cable are guided into a cassette V2 (or 14 respectively), which takes up their reserve length, in order then to reach the splice cassettes V4 and VS (or 13 respectively) by way of a connecting channel V3. Here the optical waveguide cores of the main cable HK are spliced onto prefabricated optical waveguides which are guided as bundle cores to further cassettes V6 and V7 in which the bundle cores are separated into individual hollow cores and are branched out (cassette 12) by way of couplers (the sequence of separating and splicing can be changed). The branching cores are guided, by way of likewise prefabricated optical waveguides, to further flat cassettes V8 (or 11 respectively) in which they are connected to cores of the branching cable WK (or 3 respectively). The hollow cores 22, 10 (or 24 respectively), by way of connecting channels V9, reach adapters in which the individual fibres are combined to form bundle cores and, by way of guides V11, become the branching cable -S- R WK.

Figure 4 shows a plan view of a connection unit. The inside of the hoodtype sleeve, which has been removed, is denoted by reference numeral 6. The illustrated splice cassette 11 largely corresponds to a circle segment. The edges between cassette base 9 and the circular periphery are rounded. The hollow cores 26, 27 are here guided externally on the cassette about the point of rotation 5. A guide body 44 is provided in the cassette for the S-shaped deflection of hollow cores or optical waveguide fibres. The winding space 43 has an eccentrically arranged winding body 35 about which the reserve length of the respective optical waveguide fibre guided to a splice 17 is wound up.

Each cassette can be swung individually about a common axis of rotation 5. In the remaining free space 39 can be seen the (uncut) bundle cores 10 and also the hollow cores of the branching cable 29. The reserve length of the optical waveguide fibres is deposited in the winding space 43. Holding-down means 19 hold the fibres in the winding space.

In Figure 5 one of the cassettes 11 has been swung out of the cassette stack. The splice 17 with the optical waveguide fibres 7 and 15 guided to it is to be inserted into this cassette. In the first instance the splice is pressed into the holding support 48 provided therefor and subsequently the optical waveguides are wound up in the winding space 43. The winding diameter is varied so that the reserve length is accommodated in a problem-free manner. The main cable and the cores of the branching cable are represented again, in section.

A coupler cassette 12 is diagrammatically represented in Figure 6. In the case of this variant, the point of rotation, as in the case of all the other cassettes as well, lies outside the interior space of the cassette. As here as well the supply of all hollow cores 28 is only effected from one side, it is likewise necessary to guide the fibres partly in an S-shaped manner 52. The hollow cores are guided by way of splices 40 to the connections of the couplers 51 and there branched out to, in total, 32 optical waveguide fibres.

This principle of fibre (core) guidance also holds good in the case of the splice cassette for bundle cores which is represented in Figure 7 and in which more than one bundle core 21, 31, secured in a tensionabsorbing means 49, are connected by means of splices 17 fitted in a splice holding support 40.

Figure 8 shows an extended universal connection unit, in which a further cassette block 30 has been added.

The wiring rear wall - viewed from the cassette side - is represented in Figure 9. The wiring elements 32 can be mounted side by side, with locating means 54 being provided. The horizontal core guidance 38 which is used to take up the hollow cores guided into the cassettes, changes into a vertical fibre guide channel 36 on the right-hand side, in which the cores of the branching cable 29 are guided. In the case of the upper wiring elements 37 - here only one is represented - the fibres or cores are diverted downwards.

1 k

Claims

1. Universal connection unit for optical waveguides, comprising a hoodtype sleeve housing, having a sleeve head through which connection cables are fed into the connection unit, and cassettes which are arranged so that they can be swung about a common axis of rotation wherein each cassette is dimensioned such that it does not occupy the entire crossectional area of the sleeve housing, the remaining crossectional area of the sleeve housing being provided for housing the connection cables and connecting cores.

2. Universal connection unit as claimed in claim 1 wherein cassettes having differing height are provided.

3. Universal connection unit as claimed in claim 1 or 2 in which each cassette is designed to provide optical waveguide connections for a single user.

4. Universal connection unit as claimed in any preceding claim wherein adapters are arranged on the rear wall for the separation of bundle fibres.

5. Universal connection unit according to one of the preceding claims wherein wiring elements having horizontal core guides and deflecting arrangements for vertical core guidance are provided.

6 Universal connection unit as claimed in any preceding claim wherein the cassettes can be combined to form cassette groups of differing size.

7. Universal connection unit as claimed in any preceding claim wherein the crossectional shape of the cassette is substantially a segment of a circle having an area greater than a semicircle.

8. A universal connection unit substantially as herein described with reference to the accompanying drawings.