GB2221322A

GB2221322A - Connecting optical fibres

Info

Publication number: GB2221322A
Application number: GB8818006A
Authority: GB
Inventors: David Turner Parr
Original assignee: EGERTON OPTICAL COMPONENTS LIM
Current assignee: EGERTON OPTICAL COMPONENTS LIM
Priority date: 1988-07-28
Filing date: 1988-07-28
Publication date: 1990-01-31
Anticipated expiration: 2008-07-28
Also published as: GB8818006D0; GB2221322B

Abstract

The invention provides a connector for the end-to-end abutment of two optical fibres comprising a tube 1 having a bore slightly larger than the external diameter of the optical fibres to be abutted, and having a slot 5 at or adjacent its mid-point extending along the pipe and across the axis so as to expose the bore thereof; and a holding member 11 capable of bearing down into the slot and into the exposed bore of the tube thereat so as in use to bear upon the abutting ends of glass fibres fed in one from each end of the tube. Further slots 4, 6 and holding members 10, 12 may be provided together with fibre guides 17, 18. <IMAGE>

Description

Connecting Optical Fibres This invention relates to the connection of optical fibres, and more particularly to the connection of optica fibres in an abutting end-to-end disposition.

With the increasing use cf optical fibres for telecommunication purposes in particular, the neec for a simple effective and accurate means for interconnecting two lengths of optical fibre in an abutting' end-to-end disposition to enable transmission of radiation signals cleanly throught the abutting connection becones of considerable importance. This is particularly true in view of the need for rapid connection by semi-skilled operatives sometimes in difficult envcironnements.

It has been proposed that the two ends cf optical fibres to be connected in an abutting ena-to-end disposition be physically held by a form of clip means whereafter the optical communication between the two can be provided b means of a glue or non-settlng liquid of matching refractive index to the optical fibres. However, the normal dexterity of operative is often not adequate for requirement cf accurately aligning the two optical fibres prior to clipping.

It has also been proposed, for example, that the ends of the two fibres be passed into a narrow bore tube to abut at or about its mid-point. The problem with such an arrangement is, of course, the need accurately to etch the Internal diameter of the tube with the eternal diameter of the optical fibres, to ensure aligrn:ent of the fibres.

t is an object of the present invention to overcome or at least substantially reduced these problems.

In accordance with one aspect of the present invention, there is provided a connector for the end-toend abutment of two optical fibres comprising a tube having a bore slightly larger than the external diameter of the optical fibres to be abutted, and having a slot at cr adjacent its id-point extending along the pipe and across tre axis so as to expose the bore thereof; ana a holding member capable of bearing down into the slot and into the exposed bore of the tube thereat so as in use to bear upon the abutting ends of glass fibres fea in one from. each end of the tube. Conveniently the tube is of glass.

In accordance with another aspect of the present invention, there is provided a connector for the end-toend abutting connection of two optical fibres comprising an elongate thick walled glass tube having a bore extending through its length of slightly larger internal diameter than optical fibres to be joined; the tube being provided with at least two separate slots extending axially cS the tube and penetrating through the thick walled tube to expose the bore passing therethrough; and at least two molding members each capable of penetrating within a slot into the bore of the thick walled glass tube whereby in use one holding member bears upon one or other of the optical fibres to be foined in one slot, and another holding rerLer bears upon the abutting ends of the two optical fibres within another slot.

In accordance with yet another aspect of the present Invention, there is provides a method of butt jointing to optical fibres comprising the steps of passing the end of one glass fibre into one end of a bore of a thick walled tube, the bore being slightly larger than the diameter of the fibre, past a first slct cut in the thick walled tube to a depth such as to expose the bore therethrough, and ifltO a second slot of the sa:t.e depth so that the end of the fibre lies within said second slot; fixing a first holding eber within the first slot so as to bear upon the fibre within that slot and'hold it in place; passing fror.. the other end of the thick walled tube into the bore thereof a second optical fibre into the second slot so that its end abuts the end of the first fibre; fixing a second holding member within the second slot so as to bear upon the two fibres within that slot and firmly hold them together; and applying to the abutted connection between the two fibres a glue or a non-setting liquid of matching refractive index to the optical fibres.

The thick. walled tube r.ay be provided with a third slot, si-ilar in dimensions to the first and second slots, located beyond the second slot from the first slot within which a holding rerber ray be located so as to bear, in use, upon the second optical fibre when it has been passed therethrough with its end located in the second slot.

The thick walled tube may be provided at each end with an appropriate guide for aiding the insertion of an optical fibre into the bore thereof.

The holding rerters may be caused to bear down upon the optical fibres by any appropriate means, such as by means of a thumb-screw arrangement, for example, but preferably comprise clips spring urged to engage, across the slot, with the fibre within the exposed bore.

n order that the invention may be more readily understood, one embodiment thereof will now be descriebed by way of example only with reference to the accompanying drawings in which: Figure 1 is a side elevation of a connector i accordance with the invention; Figure 2 Is an isonetric view of the connector of Figure 1; Figure 2 is a sect Ion through the thick walled glass tube on line III-III of Figure Figure 4 is a section through the thick walled glass tube on the line Iv-IV of Figure 1; and Figure 5 is a section of the clip used with the arrangement of Figure 1.

Referring now to the drawings, it will be seen that the connector comprises an elongate thick walled glass tube 1 having an outside diameter of the order of 5 mm and a bore of the order of 0.128 The tube 1 is adapted for the receipt of optical fibres 2, 3 having an external diameter of the order of 0.125 mm. The tube is provided with three slots 4, 5, 6 along its length cut across the tube i down almost to the centre line cf the tube (in practice approximately 20 to 50 micro metres above the centre line). As can be seen especially fro Figure , the slots 4, 5, 6 have flat bases 7. They have tapering and walls 8, q. resilient clips 10, 11, 12 are provided for each of the slots, having a generally flat upper portion 12 with a finger tab 15 at one side, and a generallly semi- circular lower portion 16 continuiting from the other side. As will be appreciated, a clip of such configuration fits neatly within each of the slots with the flat upper portion 13 being urged by its internal spring pressure down upon an optical fibre when disposed within the exposed bore in the slot, the lower portion of the clip fitting smoothly around the lower curve of the ferrule. The clips may be formed of moulded acrylic plastics material.

Sleeve like plastic cr glass fibre guides 17, 18 are provided at each end of the ferrule to assist the insertIon of a glass fibre into each end, the bore 19, 20 within the guides being wider than the bore of tube 1.

In practice, an optical fibre 2 is inserted fro one en: into the tube 1 and roved until its end is approx-rately mid-way along the second slot 5. A. clip 10 is now placed across the first slot o so as to bear upon the optical fibre and hold it in place within the glass tube 1. A. second fibre 3 is now inserted fro the other end of the tube 1 to meet and touch the end of the first fibre 2 approximately mid-way across the second slot 5.

The joining positions of the two fibres 2, 3 are now held down by a further clip 11 in the second slot, and a glue cr non-setting' liquid of matching refractory index placed upon the connection between the two fibres to ensure optical transmission therethrough. A glue nay also be placed in the bores 19, 20 of the guides 17, 18 to assist in securing the fibres in place. For extra security a third clip 12 may be placed across the third slot 6 to hold the second optic fibre 3 firmly within the tube 1.

The provision of the first and third slot 4, 6 adjacent each end of the tube 1 enables an operator to deal with the connection of glass fibres in either a right handed or left handed manner depending upon his natural dexterity.

By means of the invention we have provided a simple anc effective eans for optical connecting two optical fibres.

It is to be understood that the foregoing is merely exemplary of connector in accordance with the invention and that modifications can readily be made thereto without departing fro the true scope of the inventIon.

Claims

CLAIMS:

1. A connector for the end-to-end -abutment of two optical fibres comprising a tube having a bore slightly larger than the external diameter of the optical fibres to be abutted, and having a slot at or adjacent its mid-point extending along the pipe and across the axis so as to expose the bore thereof; and a holding member capable of bearing down into the slot and into the exposed bore of the tube thereat so as in use to bear upon the abutting ends of glass fibres fed in one from each end of the tube.

2. A connector for the end-to-end abutting connection of two optical fibres comprising an elongate thick walled glass tube having a bore extending through its length of slightly larger internal diameter than optical fibres to be joined; the tube being provided with at least two separate slots extending axially of the tube and penetrating through the thick walled tube to expose the bore passing therethrough; and at least two holding members each capable of penetrating within a slot into the bore of the thick walled glass tube whereby in use one holding member bears upon one or other of the optical fibres to be joined in a first slot, and another holding member bears upon the abutting ends of the two optical fibres within a second slot.

3. A connector as claimed in Claim 2 wherein the thick walled tube is provided with a third slot, similar in dimensions to the first and second slots, located beyond the second slot within which a holding member can be located so as to bear, in use, upon the second optical fibre when it has been passed therethrough with its end located in the second slot.

4. A connector as claimed in Claim 2 or 3 wherein the thick walled tube is provided at each end with an appropriate guide for aiding the insertion of an optical fibre into the bore thereof.

5. A connector as claimed in any one of the preceding claims wherein the or each holding member comprises a clip spring urged to engage, in use, across a slot, with an optical fibre within the exposed bore.

6. A connector substantially as shown in and as hereinbefore described with reference to the accompanying drawings.

7. A method of butt jointing two optical fibres comprising the steps of passing the end of one optical fibre into one end of a bore of a thick walled tube, thebore being slightly larger than the diameter of the fibrer past a first slot cut in the thick walled tube to a depth such as to expose the bore therethrough, and into a second slot of the same depth so that the end of the fibre lies within said second slot; fixing a first holding member within the first slot so as to bear upon the fibre within that slot and hold it in place; passing from the other end of the thick walled tube into the bore thereof a second optical fibre into the second slot so that its end abuts the end of the first fibre; fixing a second holding member within the second slot so as to bear upon the two fibres within that slot and firmly hold them together; and applying to the abutted connection between the two fibres a glue or a non-setting liquid of matching refractive index to the optical fibres.

8. A method of butt jointing two optical fibres substantially as hereinbefore described with reference to the accompanying drawings.