OPTICAL FIBRE CONNECTOR

Abstract: Optical fibre connector (10) having optical fibres (16) which have end optical fibre termination surfaces (64), for transfer of optical signal to and/or from the optical fibres (16). The optical fibre termination surfaces (64) are positioned at outer ends of spigot portions (56) of the optical fibre connector (10). A movable body part (40) of the connector is positionable so that the spigot portions (56) are received in bores (70) in the body part (40). Then, the optical fibre termination surfaces (64) are positioned, for use of the connector, at the inner ends of forwardly open connector openings (75) formed by outer ends of the bores (70). The body part (40) is removable to clear it from the spigot portions (56) to enable access to the optical fibre termination surfaces (64) for cleaning of these.

Description: OPTICAL FIBRE CONNECTOR This invention relates to an optical fibre connector. Optical fibre connectors are described for example in US patents 5082344, 4717234, and 4762389, and 5418875. These generally have a protruding spigot or the like, at the free end of which is positioned an end optical fibre termination surface of an optical fibre, for transfer of optical signal to or from the optical fibre. The spigot may be receivable in the bore of a further component so that the termination surface is correspondingly within that bore. In such a case, the optical fibre transfer surface may be cleaned, as is sometimes necessary to maintain effective performance, if the further component is removable. However, removal of that further component may be difficult, for example requiring disassembly of the further component. The configuration of the connector itself may also not permit easy access to the optical fibre transfer surface, even when the further component is removed. The invention seeks to provide a connector construction which facilitates cleaning of the optical fibre termination surface. In one aspect, the invention provides an optical fibre connector having an opening into which a projection of a mating optical fibre connection device may be inserted, the optical fibre connector having an optical fibre termination surface within the opening which, when the projection of the mating optical fibre connection device is inserted into the opening, is positioned relative to an optical fibre termination surface on the projection, for transmission of optical signal between an optical fibre connected to the mating optical fibre connection device and an optical fibre connected to the optical fibre connector, via the termination surfaces, the optical fibre connector being formed with a first body part having a projecting portion, at a free outer end of which the optical fibre termination surface of the optical fibre cable connector is formed, and the opening is formed in a second body part of the optical fibre connector, which second body part is movable between a first position at which the second body part is positioned such that the projecting portion extends into the opening, so that the optical fibre termination surface of the optical fibre connector is positioned within the opening for said transmission of optical signal when the projection of the mating optical fibre connection device is inserted into the opening, and a second position at which the optical fibre termination surface of the optical fibre connector is not within the opening, wherein the second body part is a press fit in the first body part to frictionally engage the first body part in the first position, being released from the first body part in the second position, and is adapted for releasable latching to the optical fibre connection device, the second body part being displaced relative to the first body part in the second position to allow access to the optical fibre termination surface of the connector for cleaning thereof. The second body part is preferably completely removable from the first part. Additional means may also be provided for releasably latching the second body part in said first position. The opening may be formed in a third part on the second body part, which forward part is, when the second body part is in the first position, positioned within a cavity of the first body part of the optical fibre connector. The opening may be defined by a bore extending through the second body part and into which the projecting portion of the first body part extends, when the second body part is in said first position. The second body part may be removable from the first body part by relative outward sliding movement thereof from the cavity. In another aspect the invention provides an optical fibre connector having first and second body parts, the first body part having a cavity with an open outer end and in which the second body part is removably received, the second body part being substantially contained within the cavity, and having a forward part which has an opening and receiving a forwardly projecting optical fibre receiving element of the first body part, the optical fibre receiving element in use of the connector receiving an optical fibre such that an optical fibre termination surface of the optical fibre is then positioned within the forward part to be forwardly accessible via said opening, at a forward end of the optical fibre receiving element, the optical fibre termination surface then being located at a location which is inwards of the open outer end of the cavity, the second body part being withdrawable from the cavity and from the optical fibre receiving element by movement thereof in an outer, forward, direction whereby to permit access to the forward end of the optical fibre receiving element to facilitate cleaning of the optical fibre termination surface of said optical fibre when received by the optical fibre receiving element. The invention is further described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is an exploded perspective view of an optical fibre connector constructed in accordance with the invention, and a mating optical fibre connection device; Figure 2 is a perspective view of the optical fibre connector of Figure 1 , together with a part of the mating optical fibre connection device of Figure 1 , with these being separated; Figure 3 is a view like Figure 2 but showing the optical fibre connector and mating optical fibre connector device interconnected; Figure 4 is a lengthwise fragmentary cross-section of the optical fibre connector of Figure 1 in a condition ready for use; Figure 5 is a view like Figure 4 but illustrating the mating optical fibre connection device positioned on the optical fibre connector; Figure 6 is a view like Figure 4 but showing a removable part of the optical fibre connector demounted from the remainder thereof; and Figure 7 is a fragmentary view corresponding to part of Figure 4, and showing a modification. The optical fibre connector 10 shown is in the form of a socket designed to fit with a mating optical fibre connection device 12 in the form of a plug. The device 12 and connector 10 are arranged for interconnecting of optical fibre cables 14. Cables 14 have optical fibres 16, surrounding inner flexible coatings 18, surrounding structural supports 20 in the form of, for example, braiding or cladding, and outer flexible coatings 22. In this case, the device 12 and connector 10 are designed as duplex devices able 5 to simultaneously connect between two pairs of cables 14, separate ones of such pairs being attached to the device 12 and the connector 10 respectively, so that optical signals input to the optical fibre 16 of one of the cables 14 attached to the device 12 can be transmitted to the optical fibre 16 of a corresponding cable 14 attached to the connector 10, the optical fibre 16 of a second cable 14, connected to the device 12, being arranged to receive optical signal 10 from an optical fibre 16 of a second optical fibre cable 14 attached to the connector 10. The device 12 shown has an outer body part 26 and an inner body part 24. It is assembled by inserting two of the cables 14 through a flexible sheath 25 into openings in the inner body part 24, such that these cables extend, at ends thereof, into side-by-side spigots 28 (Figure 15 5) formed on a front face of the inner body part 24, the inner body part 24 being then inserted into the outer body part 26. The inner flexible coatings 18 of each of the two cables 14 then extend through respective openings 30 in the inner body part 24 to terminate adjacent a at the forward end of the respective spigot 28. The free ends of the optical fibres 16, at the ends of the spigots 28, thus define optical fibre termination surfaces 36 to enable transmission of 0 optical signal into or from the associated optical fibres. The connector 10 comprises a first body part 38 and a second body part 40. First body part 38 has a cavity 42 within which the second body part 40 is removably accommodated. Cavity 42 has a forward portion 44 which terminates at a rear transverse surface 46, and two side-by - 5 side bores 48 extending rearwardly into first body part 38, from surface 46. Bores 50 which extend to the exterior of the body part 38 extend from inner ends of the respective bores 48, and coaxially with respect to these. Bores 48 receive therewithin respective generally tubular fibre receiving elements 52, such that rear spigot portions 54 thereof are so received in adjacent ends of bores 50 and forward spigot portions 56 thereof extend forwardly into cavity 30 42. Outwardly extending flanges 58 on the elements 52, at junctions between spigot portions 54, 56 thereof, are a neat fit within bores 48 and lie flush against the inner ends of bores 48 so that the elements 52 are substantially fixedly located on first body part 38. Optical fibre cables 14 are secured to the connector 10 in a similar way to above described in relation to the device 12. In particular, the structural supports 20 are mechanically secured to the first body part 38 to provide mechanical support therefore, and the inner coatings 18 and fibres 16 themselves accommodated within central bores 60 within the elements 52 so that, at forward ends of the elements 52, the free end surfaces of the fibres 16 define optical fibre termination surfaces 64, for passage of optical signal to and/or from the fibres 16. The forward ends of the spigot portions 56 are, as shown in Figures 4 to 6, positioned somewhat inwardly of the outer open end of cavity 42. Second body part 40 of connector 10 comprises two generally tubular side-by-side parts 66 (Figure 1) which interconnect at a transverse wall 68 intermediate their ends. These are sized so that rear ends thereof are neat fits within the bores 48 when the part 40 is inserted into the cavity 42. As shown in Figure 4, when so inserted, the spigot portions 56 of the elements 52 are neatly accommodated in the central coaxial bores 70 through the respective side-by- side parts 66 of the second body part 40. In this condition, too, the transverse wall 68 is pressed against the transverse surface 46 of the cavity 42. The second body part 40 may be made a stiff press fit within the cavity 42, by suitably sizing the transverse dimensions of the rear ends of the parts 66 as compared with the transverse dimensions of the bores 48 and/or by suitably configuring or sizing the outer periphery of the wall 68 so that it frictionally engages the side surface of the cavity 42. The forward portion 44 of cavity 42 defines, forwardly of wall 68 on part 40, a forwardly open recess 80 (Figure 4). The forward parts of the bores 70 form forwardly open openings 75, at the bottom of which are situated the respective optical fibre termination surfaces 64. As shown in Figure 5, the device 12 is engageable with the connector 10 by advancing it towards the recess 80 such that the forward end of each spigot 28 passes into a respective one of the bores 48 and so that the ends thereof are brought against the outer surfaces of the flanges 58 on the elements 52. In this arrangement, the optical fibre termination surfaces 64, 36 of the optical fibres 16 associated with connector 10 and device 12 are brought into aligned touching relationship to enable transfer of optical signal between the so-coupled fibres 16. One or other of the spigot portions 56 and spigots 28 may be resiliently biased against the other to ensure proper contact as between the optical fibre termination surfaces 64, 36 as known in the art. The second body part 40 has opposed tongue-like projections 72 extending forwardly from the wall 68, and these engage in recesses 74 (Figure 5) formed at the front end of the device 12, between the parts 24 and 26, for releasably latching the connector 10 and device 12 together. To permit access to the optical fibre termination surfaces 64 of the optical fibre cables 16 which are received by the respective spigot portions 56, the part 40 may be removed from the cavity 42 by pulling it forwardly, in which case the spigot portions 58 extend forwardly of the transverse surface 46 and are positioned centrally within the relatively large forward portion 44 of cavity 42, to enable ready cleaning of the optical fibre termination surfaces 64. The part 40 is readily replaceable on spigot portions 56 by re-inserting it into the cavity 42. The invention may be applied to duplex connectors as described or to connectors having only one or any number of optical fibre termination surfaces 64, and, for example to connectors otherwise of known form such as so-called "SC" connectors. In particular, the latching of the connector parts 38, 40 may be effected by means of cooperating latching components of the kind employed in SC connectors. The second body part 40 may be held in position on the first body part 30 solely by frictional engagement, although alternative or additional releasable holding may be provided by, for example, provision of suitable snap-engagement components on the first and second body parts. Figure 7 shows a modified second body part 40 having at its rear face a rearwardly projecting tongue 76 receivable in a recess 82 extending inwardly from surface 46 of cavity 42 when the second body part 40 is moved into cavity 42. The tongue 76 has a free end part 84 which is sidewardly displaced against natural resilience of the tongue during insertion of the second body part 40 into recess 42, until the tongue 76 snaps outwardly under resilient bias to cause the end part 84 to catch on a transverse side 86 of the recess 82, to effect holding of the second body part 40 to the first body part 38. The free end part 84 of the tongue 76 can be sidewardly displaced by inserting a screwdriver into a side opening 88 in first body part 38, to release it from engagement with the side 86, to enable withdrawal of the second body part 40 from first body part 38. By the described constructions, the second body part 40 is removable from the first body part 38 by forward movement out of the cavity 42, without disassembly of the first body part 38. The provision of the tongue-like projections 72 on the removable second body part 40 enables these to be cleared from the cavity when the second body part 40 is removed, so as to provide good access to the optical fibre termination surfaces 64, for cleaning these. The described arrangement has been advanced merely by way of explanation any many modifications may be made thereto without departing from the spirit and scope of the invention as defined in the appended claims.

Claims: CLAIMS :- 1. An optical fibre connector having an opening into which a projection of a mating optical fibre connection device may be inserted, the optical fibre connector having an optical fibre termination surface within the opening which, when the projection of the mating optical fibre connection device is inserted into the opening, is positioned relative to an optical fibre termination surface on the projection, for transmission of optical signal between an optical fibre connected to the mating optical fibre connection device and an optical fibre connected to the optical fibre connector, the optical fibre connector being formed with a first body part having a projecting portion, at a free outer end of which the optical fibre termination surface of the optical fibre cable connector is formed, and the opening is formed in a second body part of the optical fibre connector, which second body part is movable between a first position at which the second body part is positioned such that the projecting portion extends into the opening, so that the optical fibre termination surface of the optical fibre connector is positioned within the opening for said transmission of optical signal when the projection of the mating optical fibre connection device is inserted into the opening, and a second position at which the optical fibre termination surface of the optical fibre connector is not within the opening, wherein the second body part is a press fit in the first body part to frictionally engage the first body part in the first position, being released from the first body part in the second position, and is adapted for releasable latching to the optical fibre connection device, the second body part being displaced relative to the first body part in the second position to allow access to the optical fibre termination surface of the connector for cleaning thereof. 2. An optical fibre connector as claimed in claim 1 , wherein the opening is defined by a bore extending through the second body part, and into which the projecting portion of the first body part extends when the second body part is in said first position. 3. An optical fibre connector wherein the opening is formed in a forward part on the second body part, which forward part is, when the second body part is in the first position, positioned within a cavity of the first body part of the optical fibre connector. 4. An optical fibre connector as defined in claim 3 wherein the projecting portion of the first body part is formed on a separately formed optical fibre receiving element received in said cavity. 5. An optical fibre connector according to claim 4 wherein the cavity and the second body part together define a recess into which the projection of the mating optical fibre connection device is receivable. 6. An optical fibre connector according to any preceding claim wherein the second body part is removable from the first body part. 7. An optical fibre connector having first and second body parts, the first body part having a cavity with an open outer end and in which the second body part is removably received, the second body part being substantially contained within the cavity, and having a forward part which has an opening and receiving a forwardly projecting optical fibre receiving element of the first body part, the optical fibre receiving element in use of the connector receiving an optical fibre such that an optical fibre termination surface of the optical fibre is then positioned within the forward part to be forwardly accessible via said opening, at a forward end of the optical fibre receiving element, the optical fibre termination surface then being located at a location which is inwards of the open outer end of the cavity, the second body part being withdrawable from the cavity and from the optical fibre receiving element by movement thereof in an outer, forward, direction whereby to permit access to the forward end of the optical fibre receiving element to facilitate cleaning of the optical fibre termination surface of said optical fibre when received by the optical fibre receiving element. 8. An optical fibre connector according to claim 7 wherein the second body part has engaging projections for releasably retaining said optical fibre connector device in the cavity. 9. An optical fibre connector according to claim 7 wherein the second body part is a press fit in the first body part. 10. An optical fibre connector according to any one of claims 7 to 9 wherein interlocking components are provided for releasably locking the second body part in position on the first body part. AMENDED CLAIMS [received by the International Bureau on 08April 1999 (08.04.99); original claims 1,3 and 7 amended; remaining claims unchanged (2 pages)] 1. (Amended) An optical fibre connector having an opening into which a projection of a mating optical fibre connection device may be inserted, the optical fibre connector having an optical fibre termination surface within the opening which, when the projection of the mating optical fibre connection device is inserted into the opening, is positioned relative to an optical fibre termination surface on the projection, for transmission of optical signals between an optical fibre connected to the mating optical fibre connection device and an optical fibre connected to the optical fibre connector, the optical fibre connector being formed with a first body part having a projecting portion, at a free outer end of which the optical fibre termination surface of the optical fibre cable connector is formed, and the opening is formed in a second body part of the optical fibre connector, which second body part is movable between a first position at which the second body part is positioned such that the projecting portion extends into the opening, so that the optical fibre termination surface of the optical fibre connector is positioned within the opening for said transmission of optical signal when the projection of the mating optical fibre connection device is inserted into the opening, and a second position at which the optical fibre termination surface of the optical fibre connector is not within the opening, wherein the second body part is a press fit in the first body part to frictionally engage the first body part in the first position, being released from the first body part in the second position, and is adapted for releasable latching to the optical fibre connection device, the second body part being displaced relative to the first body part in the second position to allow access to the optical fibre termination surface of the connector for cleaning thereof. 2. An optical fibre connector as claimed in claim 1, wherein the opening is defined by a bore extending through the second body part, and into which the projecting portion of the first body part extends when the second body part is in said first position. 3. (Amended) An optical fibre connector as claimed in claim 1 wherein the opening is formed in a forward part on the second body part, which forward part is, when the second body part is in the first position, positioned within a cavity of the first body part of the optical fibre connector. 4. An optical fibre connector as defined in claim 3 wherein the projecting portion of the first body part is formed on a separately formed optical fibre receiving element received in said cavity. 5. An optical fibre connector according to claim 4 wherein the cavity and the second body part together define a recess into which the projection of the mating optical fibre connection device is receivable. 6. An optical fibre connector according to any preceding claim wherein the second body part is removable from the first body part. 7. (Amended) An optical fibre connector having first and second body parts, the first body part having a cavity with an open outer end and in which the second body part is removably received, the second body part being substantially contained within the cavity, and having a forward part which has an opening for receiving a forwardly projecting optical fibre receiving element of the first body part, the optical fibre receiving element, in use of the connector, receiving an optical fibre such that an optical fibre termination surface of the optical fibre is then positioned within the forward part to be forwardly accessible, via said opening, at a forward end of the optical fibre receiving element, the optical fibre termination surface then being located at a location which is inwards of the open outer end of the cavity, the second body part being withdrawable from the cavity and from the optical fibre receiving element by movement thereof in an outer, forward, direction whereby to permit access to the forward end of the optical fibre receiving element to facilitate cleaning of the optical fibre termination surface of said optical fibre when received by the optical fibre receiving element. 8. An optical fibre connector according to claim 7 wherein the second body part has engaging projections for releasably retaining said optical fibre connector device in the cavity. 9. An optical fibre connector according to claim 7 wherein the second body part is a press fit in the first body part.

Inventors: LEES KENNETH LESLIE, LEES, KENNETH, LESLIE
Applicants: KRONE AG, LEES KENNETH LESLIE, KRONE AKTIENGESELLSCHAFT, LEES, KENNETH, LESLIE
Application year: 1998
Main classification: G02B6
IPC codes: G02B6