DEVICE FOR POSITIONING THE END OF AN OPTICAL FIBRE IN A SLEEVE

Abstract: Device for positioning the end of an optical fibre (1) in a sleeve (10) including at least three mutually parallel rods (2, 3, 4, 5) forming a passage between themselves for accommodating the fibre end, one end of the rods being intended for insertion into the sleeve (10). In accordance with the invention, each rod has two flat surfaces cutting each other at a long edge, one flat surface of each rod lying against a flat surface of an adjacent rod such that said long edges of the rods extend parallel to, and distributed round the symmetrical axis of said passage. The rods are mutually displaceable in relation to said symmetrical axis, while the engaging surfaces glide against each other for changing the size of the passage to suit different fibre diameters. The ends of the rods intended for insertion in the sleeve have a third flat surface (11, 12, 13, 14) forming equally as great angles with the two flat surfaces already mentioned, this surface being intended to engage against a complemental flat surface in the sleeve (10).

Description: DEVICE FOR POSITIONING THE END OF AN OPTICAL FIBRE IN A SLEEVE TECHNICAL FIELD The present invention relates to a device for positioning the end of an optical fibre in a sleeve and includes at least three mutually parallel rods, forming between themselves a passage for receiving the fibre end, one end of the rods being intended for accommodation in the sleeve. BACKGROUND ART Such devices, which can be used for such as contactors, connection means or auxiliary measuring means for optical fibres, are known from DE-B2-2757216 and EP-B1-015046, for example. These known devices are complicated in their construction, however, and are therefore expensive to manufacture. DISCLOSURE OF INVENTION The object of the present invention is to provide an apparatus of the kind described in the introduction that is easy and cheap to manufacture, and that gives a distinct positioning of an optical fibre, irrespective of fibre diameter. This is achieved by the device in accordance with the invention being given the distinguishing features disclosed in the claim. DESCRIPTION OF FIGURES The invention will now be described in detail below with reference to the accompanying drawing, on which Figure 1 is a perspective view of an embodi¬ ment of a device in accordance with the invention, Figure 2 is an end view of a device according to Figure 1, and Figure 3 is an end view of a second embodiment of the device in accordance with the invention. OMPI PREFERRED EMBODIMENTS Figure 1 illustrates an embodiment of a device in accordance with the invention for positioning the end of an optical fibre 1 in a sleeve 10. The illustrated embodiment includes four mutually parallel rods 2, 3, 4 and 5, between themselves forming a passage accommodating the end of the fibre 1, the sleeve 10 accommodating one end of each rod. Each of the rods 2-5 has two flat surfaces, and in the illustrated case these surfaces meet each other at right-angles along a long edge 6, 7, 8, and 9, as in Figure 2. In accordance with the invention, one of the two flat surfaces on the respective rod engages against one of the two flat surfaces on a juxtaposed rod such that the long edge 6-9 of the respective rod 2-5 extends parallel to, and distributed round the axis of symmetry of the passage for the fibre 1 formed between the rods. The rods 2-5 are mutually, displaceable in relation to this axis of symmetry, while gliding against their mutually engaging surfaces for the purpose of changing the size of the passage such as to enable the accommodation of fibres having different diameters. The fibre and its surrounding rods may be glued to each other to ensure fixation of the rods and the fibre accommodated between them. To enable the accommodation of the rods in a single sleeve 10 for different diameters of the fibre 1, the ends of the rods 2-5 intended for insertion in the sleeve are formed with a third flat surface 11, 12, 13 and 14, which is preferably parallel to the longitudinal edge of the respective rod, in the present case forming an angle 45 to both flat surfaces cutting each other at right- angles, each of which engages against its complementary surface on adjacent rods. The other ends of the rods are formed with a quadratic section in the illustrated embodiment, but may of course be formed in som other way. In the embodiment illustrated in figures 1 and 2, the ends of the rods 2-5 inserted in the sleeve 10 are formed as identical isosceles right-angular triangles. In this embodiment the interior walls of the sleeve 10 enclose a cavity of substantially quadratic cross-section. To enable the accommodation in the sleeve of mutually displaced rods for placing fibres of different diameters between the rods, the sleeve is provided with longitudinal recesses 15, 16, 17 and 18 along the intersection lines between the mutually perpendicular interior walls. The size of the recesses 15-18 depends on the diameter of the fibre 1 that is to be placed between the rods 2-5. An alternative embodiment of the sleeve and the rod ends inserted in it is illustrated in Figure 3. Here, the sleeve denoted by the numeral 10 has a cavity of purely quadratic cross-section for accommodating the rod ends. These, denoted 2', 3 1 , 4' and 5', are chamfered at their sharp corners in a manner illustrated in Figure 3, to enable their reception in the sleeve 10' when mutually displaced, thus enabling fibres of different diameters to be placed between the rods. The rod ends inserted in the sleeve naturally do not need to be formed identically alike, but the advantage in doing this is that the set of rods may be inserted in the sleeve with optional rotational orientation. A similar set of rods may be inserted in the other end of the sleeve 10 illustrated in Figure 1, to obtain contact between the fibre 1 and the not illustrated fibre in the other set of rods. The invention is naturally not confined to the use of four rods, it being possible to use three, five or more. In all cases, however, the sum of the angles between both longitudinally intersecting surfaces of the respective rods must attain 360°. In the case with three rods, this angle will thus be 120°, while the angle between the third flat surface of the respective rod and each of its other two flat surfaces will be 60°. OMPI

Claims: CLAIM Device for positioning the end of an optical fibre (1) in a sleeve (10), and including at least three mutually rods (2, 3, 4, 5) forming between themselves a passage for accommodating the fibre end, one of their ends being intended for accommodation in the sleeve (10), characterized in that each rod has a first and a second flat surface, both said surfaces intersecting each other at a long edge (6, 7, 8, 9) one flat surface of each rod engaging against a flat surface of an adjacent rod such that said long edges of the rods extend parallel to, and distributed round the symmetrical axis of said passage; in that the rods (2, 3, 4, 5) are mutually displaceable in relation to said symmetrical axis, with their engaging surfaces gliding over each other for changing the size of the passage to suit different fibre diameters; and in that the respective rod end intended for insertion in the sleeve (10) has a third flat surface (11, 12, 13 14) forming equally as great angles with the two surfaces already mentioned, this surface being intended to engage against a complemental flat surface in the sleeve (10). OMFi.

Inventors: SERRANDER HANS ROLAND, SERRANDER, HANS, ROLAND
Applicants: ERICSSON TELEFON AB L M, TELEFONAKTIEBOLAGET LM ERICSSON
Application year: 1984
Main classification: G02B7
IPC codes: G02B6