AU2003200269B2 - Splicing Device for Welding Optical Fibers - Google Patents

Description

S&F Ref: 389900D2

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

Name and Address of Applicant: Actual Inventor(s): Address for Service: Invention Title: Siemens Aktiengesellschaft Wittelsbacherplatz 2 D-80333 Munchen Germany Rudolf Brugger, Dieter Krause Spruson Ferguson St Martins Tower,Level 31 Market Street Sydney NSW 2000 (CCN 3710000177) Splicing Device for Welding Optical Fibers The following statement is a full description of this invention, including the best method of performing it known to me/us:- IP Australia Documents were receied on' 2 AN2003

C

Batch No: 5845c Splicing device for welding optical fibers In order to connect optical fibers detachably, use is made of optical fiber plug connectors, in whose plug connector parts, which are hollow cylindrical and consist of ceramic, the glass fibers to be coupled are intended to be bonded as centrally as possible. In this case, it is already known previously to bond short glass fibers pieces into the end regions to be coupled of the plug connector parts, and to couple up the optical fibers leading further within these plug connector parts with the aid of an immersion liquid. However, the advantage of exact centring of the glass fibers in the coupling region is opposed here by the disadvantage of high attentuation of the coupling points within the plug connector parts.

In addition, there is the risk that the immersion liquid will dry out. The introduction of contaminants into the coupling region can scarcely be avoided when pushing the optical fiber into the associated plug connector parts.

The abovementioned disadvantages of coupling optical fibers with the aid of an immersion liquid can be avoided by welding the optical fibers. Appropriate splicing devices for welding optical fibers, such as known from US-A-5 218 184, for example, are, however, not suitable for coupling glass fibers bonded into the ceramic plug connector parts to optical fibers leading further, in or close to the plug connector parts.

US-A4 220 394 discloses an optical fiber plug connector whose hollow cylindrical plug connector parts have, in the region of the butt point between the bondedin glass fiber piece and the optical fiber leading further, four openings which are arranged opposite one another in pairs. In the region of these openings, it is then possible for the two optical fibers to be welded to each other with the aid of a microwelding torch. The nozzle of the microwelding torch, which is designed as a hollow needle, is in this case introduced into one of the four openings, so that further 2 openings can be used for introduction of a gripper and for the illumination and observation of the splice point.

US-A-4 598 974 discloses a further optical fiber plug connector whose hollow cylindrical plug connector parts, in the region of the butt point between the bonded-in glass fiber piece and the optical fiber leading further, have a splicing chamber. Two electrodes project into this splicing chamber and, by igniting an arc, effect the welding of the two optical fibers. The two electrodes are integral constituent parts of the optical fiber plug connectors, which remain on the associated plug connector parts even after the splicing operation.

The invention specified in claim 1 is based on the problem of providing a splicing device for welding optical fibers with which glass fibers bonded into the ceramic plug connector parts can be welded onto optical fibers leading further, in or close to the plug connector parts. The accessibility of the splice points located inside the plug connector parts can in this case be ensured, for example, by an appropriate transverse-axial groove of a plug connector part.

The invention is based on the discovery that, in the event of pivoting in the plug connector part, which is held in a first receptacle, and the glass fiber bonded therein between the welding electrodes, and in the event of pushing in axially the optical fiber held in a second receptacle, optimum conditions are provided for the adjustment of the optical fibers to be connected to each other and for the quality of the weld.

In addition to the use outlined as a plug connector splicing instrument, the splicing device according to the invention can be generally used as well for welding optical fibers in or close to other optical components.

3 Advantageous refinements of the invention emerge from the subclaims.

An exemplary embodiment of the invention is illustrated in the drawing and will be described in more detail below.

Figure 1 shows a splicing device for welding optical fibers in optical fiber plug connectors, in plan view, Figure 2 shows the splicing device according to Figure 1 in a first side view, Figure 3 shows the splicing device according to Figure 1 in a second side view, Figure 4 shows a cross section through the splicing device according to Figure 1 at the level of the splice point.

Figure 5 shows the principle of pivoting in the end of the first optical fiber located in the optical fiber plug connector between the electrodes that are arranged at the level of the splice point, Figure 6 shows a partially sectioned side view of the first receptacle necessary for the pivoting operation according to Figure Figure 7 shows a plan view of the first receptacle illustrated in Figures 4 and Figure 8 shows a side view of the splice point of the splicing device according to Figure 1 and the second receptacle, 4 adjustable in the axial direction, for the second optical fiber, Figure 9 shows a plan view of the second receptacle according to Figure 8, Figures 10 and 11 show a crimp tool that is integrated into the splicing device according to Figure 1, in an axial plan view and in cross section, respectively, and Figure 12 shows a longitudinal section through the optical fiber plug connector after the welding of the optical fibers.

Figures 1 to 3 show a plan view and two different side views of a splicing device for welding optical fibers in optical components, the optical components OBE which can be seen in Figure 2, in Figure 8 and in particular in Figure 12, being optical fiber plug connectors made of ceramic. Bonded into the optical component is OBE a short piece of a first optical fiber LWLI, which in the region a transverse-axial groove NU of the optical component OBE is intended to be connected to a second optical fiber LWL2 leading further by means of welding (cf. Figures 8 and 12).

In order to hold the optical component OBE and the associated first optical fiber LWL1, a first receptacle Al is used, which can be pivoted about a pivot axis designated by SA. The first receptacle Al, which is shown in the pivoted up state in Figure 1, can be pivoted downward about the pivot axis SA in such a way the the end of the first optical fiber LW1 lies opposite and axially aligned with the end of the second optical fiber LWL2 in the splicing region.

In order to receive the second optical fiber LWL2, a second receptacle A2 is used, which is illustrated in Figures 1 and 2 and can be adjusted in the axial direction AX.

5 In order to observe the ends to be welded together of the optical fibers LWL1 and LWL2, provision is made of an optical device OE, which can be seen in Figures 2 and 3 and is arranged on a pivotable flap KLA.

According to Figure 3, the flap KLA can be pivoted up about an axis AC1. Figure 2 also shows that the optical device OE for its part can be pivoted on the flap KLA about an axis AC2 and by this means can be laid against the flap KLA when the welding device is being transported. The optical device OE can be constructed as a microscope or else as an imaging device which images the splicing region on a monitor.

As an alternative to the pivotable first receptacle Al, it is also possible for an additional receptacle, designated by ZA in Figure 1, to be used for optical fibers LWL1, so that the special instrument can also be used as a normal splicing device for welding optical fibers.

In the plan view according to Figure 1, it is also possible to see a first knob KNI for switching on the instrument, a second knob KN2 for prewelding and main welding, a red light-emitting diode LDR for indicating the switched-on state, a rotary knob DK for setting various welding programs, and a push button TA for opening and closing the flap KLA and for actuating a crimping tool KW illustrated in Figures 10 and 11.

Figure 4 shows the actual splicing region having two electrodes E which are arranged at a distance from each other and, by igniting and arc, effect the welding of the optical fibers LWLI and LWL2, which are not illustrated here in more detail (cf. Figure The two electrodes E are in each case connected via clamps KLE to associated welding cables SKA for the supply of the welding current. In order to set the axial 6distance between the two electrodes E, stop pins AST arranged at the ends are provided.

Arranged on the basic body DK, which serves as electrode holder, is the axis AC1 which has already been mentioned and on which the flap KLA is pivotable mounted together with the optical device OE. In the basic body GK, which consists of an electrically insulating plastic, there are also arranged a first illumination device BELl for transmitted light illumination of the splice point and a second illumination device BEL2 for incident illumination of the splice point, both the illumination devices being formed by light-emitting diodes. Associated with the second illumination device BEL2 is a prismatic rod PS which is arranged in the flap KLA and which directs the light onto the splice point at an angle of to the horizontal direction.

Figure 5 shows how the optical component OBE that is rotatably arranged in the first receptacal Al, together with the end of the first optical fiber LWL1, is introduced between the two electrodes E by pivoting the first receptacle Al about the pivot axis SA in the direction of the arrow PF. The optical component OBE, which is not illustrated in Figure 5, is inserted into a hollow cylindrical component receptacle BA which for its part is arranged in an ant-rotational means VS. Using a lever HEB, the component receptacle BA with the optical component OBE can be rotated. In this case, the welding position of the lever HEB is illustrated in Figure 5, in which position the groove NU of the optical component OBE runs in alignment with the electrodes E.

Figure 6 shows a position rotated through 900 of the lever HEB, in which position the groove NU of the optical component OBE is aligned in such a way that transmitted light illumination of the splice point from below is enabled with the aid of the first illumination device BELl.

7 Figure 7 shows a plan view of the first receptacle Al in the position of the lever HEB illusrated in Figure 6.

Figure 8 and 9 show the construction and the mode of operation of the second receptacle A2, which can be adjusted in the axial direction AX of the optical fibers LW1 and LW2 to be welded, for the second optical fiber LWL2. The second receptacle A2 in this case carries an interchangeable adapter AD for holding the fiber or the cable of the second optical fiber LWL2. For the purpose of coarse adjustment of the second receptacle in the axial direction AX, and for the purpose of inserting the second optical fiber LWL2 into the optical component OBE, use is made of a lever system HS having a lever HB that can pivot about an axis AC3. The axial guidance of the second receptacle A2 is performed in this case by the pivot axis SA and a guide F, running parallel thereto, both of which are illustrated by way of example in Figure 4. After the outlined coarse adjustment, axial fine adjustment of the second receptacle A2 is carried out with the aid of a micrometer screw MMS arranged on the lever HB and a ball KU, said axial fine adjustment setting the axial gap between the two optical fibers LWLI and LWL2 within the optical component OBE, for example to a value of 7 to 10 pm. During the actual welding operation, the second optical fiber LWL2 must then be pushed further in the axial direction AX, this axial delivery movement in the second receptacle A2 being performed automatically by a piezoelectric drive PA adjacent to the ball KU.

Figures 10 and 11 show a crimping tool KW, integrated into the splicing device, for a crimp sleeve KH which is to be connected to the cable of the second optical fiber LWL2 and the optical components OBE. The lower part UT of the crimping tool KW is firmly arranged in the basic body GK, whereas the upper part OT is fitted in the flap KLA. By this means, following the actuation of the push button TA (cf. Figure a crimping operation is initiated when the flap KLA is closed.

8 Figure 12 shows a longitudinal section through the optical component OBE, which is constructed as an optical fiber plug connector. As has already been mentioned in connection with Figures 2 and 8, a short piece of the first optical fiber LWL1 is bonded into the optical component OBE, said piece being connected by welding to the optical fiber LWL2 leading further in the region of the transverse-axial groove NU. The splice point is designated by SPS. The crimp sleeve RH already mentioned in connection with Figure 11 effects a secure connection between the cable of the second optical fiber LWL2 and the ceramic body of the optical component OBE via a connecting part VT which consists of steel. In order to fix the optical component OBE in the axial direction, provision is made of a stop ANS of annular design.

Claims (8)

1. A splicing device for welding optical fibers (LWL1, LWL2) in or close to optical components (OBE), in particular optical fiber plug connectors, having I\O a first receptacle (Al) for the optical component (OBE) and the 0associated first optical fiber (LWL1); O a second receptacle which can be adjusted in the axial direction N (AX) of the optical fibers (LWL1, LWL2) to be welded, for the second optical fiber (LWL2); an optical device (OE) for observing the ends to be welded of the optical fibers (WLW1, WLW2), and having; two electrodes which are arranged at a distance from each other and effected the welding of the optical fibers (LWL1, LWL2) by igniting an arc; the first receptacle (Al) being mounted such that it can pivot about a pivot axis (SA) that is aligned parallel to the axial direction (AX) in such a way that end of the first optical fiber (LWL1) that is located in or close to the optical component, (OBE) can be pivoted in between the two electrodes

2. The slicing device as claimed in claim 1, characterized in that the optical component (OBE) is mounted in the first receptacle (Al) such that it can be rotated about the optical axis of the first optical fiber (LWL1).

3. The slicing device as claimed in claim 1 or 2, characterized by; a lever system (HS) for the course adjustment of the second receptacle (A2) in the axial direction and by; [R:\LIBE104419.doc:ed o a micrometer screw (MMS) for fine adjustment of the second receptacle O N in the axial direction (AX). 0 4. The slicing device as claimed in of claims 1 to 3, characterized by a piezoelectric drive (PA) of the second receptacle (A2) for the delivery movement, acting in the axial direction of the second optical fiber (LWL2) during the welding O operation. The splicing device as claimed in one of claims 1 to 4, characterized in that the second receptacle (A2) carries an interchangeable adapter (AD) to hold the fiber or the cable of the second optical fiber (LWL2).

6. The splicing device as claimed in one of claims 1 to 5, characterized by an additional receptacle which can be used alternatively to the first receptacle for first optical fibers (LWL1) in the form of fibers or cables.

7. The splicing device as claimed in one of claims 1 to 6, characterized in that the optical device (OE) is arranged on a pivotable flap (KLA).

8. The splicing device as claimed in one of claims 1 to 7, characterized by an integrated crimping tool (KW) for crimp sleeves (KH) to be connected to the cable of the second optical fiber (LWL2).

9. The splicing device as claimed in claim 8 in conjunction with claim 7 or 8, characterized in that the upper part (OT) of the crimping tool (KW) is arranged in the flap (KLA). The splicing device as claimed in one of claims 1 to 9, characterized by a first illumination device (BEL 1) for transmitted light illumination of the splice point.

11. The splicing device as claimed in one of claims 1 to 10, characterized by a second illumination device (BEL2) for incident light illumination of the splice point. [R:\LIBE]04419.doc:edg -11 O 12. A splicing device substantially as described herein with reference to the CI accompanying drawings. DATED this Thirtieth Day of September, 2004 Siemens Aktingesellschaft Patent Attorneys for the Applicant D SPRUSON FERGUSON [R:\LIBE]04419.doc:edg'