Abstract:
An optical fibre connector system, including an optical connector disposed therein, and a recess allowing a through connector to be connected to the optical connector. The optical fiber connector system includes an engagement mechanism that acts on the optical connector to prevent release of the through connector when connected to the optical connector, and which is operable to enable release of the through connector. The engagement mechanism is a movable element that normally engages the connector to the support and which can be moved to disengage the connector from the support, thereby releasing the through connector.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
   This patent application is a continuation application of U.S. patent application Ser. No. 10/391,404, filed Mar. 17, 2003, now U.S. Pat. No. 7,163,342, issued Jan. 16, 2007, entitled “An Optical Fibre Connector System”, naming Bruce E. Robertson and Ross Stuart Williams as inventors, which relates to and claims priority to corresponding Australian Patent Application No. PS1207/02, which was filed on Mar. 18, 2002. 

   TECHNICAL FIELD 
   The present invention relates to an optical fibre connector system. 
   BACKGROUND OF THE INVENTION 
   The fibre optic communications industry currently uses a wide variety of different optical fibre connector types. The connectors are used to interconnect and disconnect optical fibres used for light transmission. To provide a satisfactory connection requires optical connectors to be high precision mechanical devices, with tolerances on certain parts being on the order of 1 micron. The connectors are difficult to manufacture and many years of engineering effort have been required to perfect and develop the various types of connectors, most of which are manufactured in large quantities. The different types of connectors are essentially all incompatible and, as the industry evolves, new types are being developed with improved characteristics. Despite the wide variety of connector types available, there has been a general lack of user-installable and inexpensive components for adapting between connector types. A number of adaptors for connecting different types of connectors are available but tend to be severely limited in application, due to either excessive cost or limited performance. Some adaptors are used with optical instrumentation, but are usually incorporated into the instrumentation, so that the instrument can only be used to connect to one type of connector. A user purchasing the instrument therefore can only make use of it with one type of optical connector. 
   It is desired to provide an optical connector system that alleviates one or more difficulties of the prior art, or at least a useful alternative to existing connector systems. 
   SUMMARY OF THE INVENTION 
   In accordance with the present invention, there is provided an optical fibre connector system, including an optical connector disposed therein, a recess allowing a through connector to be connected to said optical connector, and an engagement mechanism which acts on said optical connector to prevent release of said through connector when connected to said optical connector, and which is operable to enable release of said through connector. 
   Preferably, said connector system includes a support which includes said recess and holds at least part of said optical connector which includes a terminating part of an optical fibre. 
   Preferably, said engagement mechanism includes a movable element which normally engages said connector to said support and which is moved to disengage said connector from said support to enable said release of said through connector. 
   Preferably, said movable element is normally biased. 
   Preferably, said element is a resilient arm which is attached to part of said connector. 
   Preferably, said connector system includes a support and a connector assembly having means for reversibly engaging said support. 
   Preferably, said optical connector includes at least two components that are engaged to prevent said release of said through connector, said release being enabled by disengaging at least one of said components. 
   Preferably, said components are relatively movable to enable said release, and said release is enabled by disengaging one of said components. 
   Preferably, said components are engaged with said support to prevent said release, and said release is enabled by disengaging one of said components. 
   Preferably, said connector assembly includes an inner sleeve assembly for supporting an optical fibre and for reversibly engaging said support to enable said release of said through connector, and an outer sleeve for supporting said inner sleeve and for reversibly engaging said support. 
   Preferably, said optical connector includes an SC, LC, or MU connector. 

   
     BRIEF DESCRIPTION OF THE INVENTION 
     Preferred embodiments of the present invention are hereinafter described, by way of example only, with reference to the accompanying drawings wherein: 
       FIG. 1  is an isometric view of a preferred embodiment of an optical fibre connector system; 
       FIG. 2  is an isometric view of two of the connector systems and through connectors for connecting optical fibre cables to the systems; 
       FIG. 3  is an isometric view of the rear of the connector system, showing separation of a connector assembly and a support assembly of the system; 
       FIG. 4  is an isometric exploded view of the support assembly; 
       FIG. 5  is an isometric exploded view of the connector assembly; 
       FIG. 6  is an isometric cross-section view of an inner sleeve assembly of the connector assembly; 
       FIG. 7  is an isometric view of the inner sleeve assembly; 
       FIG. 8  is an isometric view of the connector assembly; and 
       FIGS. 9 and 10  are isometric cross-section views of the connector system connected to a through connector. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Optical fibres connectors are made according to a number of different designs which, although incompatible, have similar characteristics. Standard connector types include, for example, ST. SC, LC, MU, FC, D4, LSA, E2000, EC and SMA, which are made by a number of manufacturers. The connectors are used to make an optical connection between two optical fibres, and are positioned at the ends of an optical fibre, with the fibre tip being polished to provide a desired interconnecting surface. To make a connection between two fibres, two optical connectors are required, together with a through connector which is used to align the optical connectors so that the fibres are properly aligned and light is transmitted from one fibre to the other. A through connector includes an alignment sleeve which is a precision component used to align the optical fibres of the two optical connectors. A spring mechanism may be provided within a connector to provide controlled pressure on the end face of the fibre when a connection is made to improve control optical parameters such as forward loss and return loss. 
   As shown in  FIGS. 1 and 3 , an optical fibre connector system includes an SC connector assembly  10  located within a receptacle or support  12 . As shown in  FIG. 4 , the support  12  is part of a support assembly  13  that allows the connector system to be mounted on a faceplate or a wall, securing the connector system for use in optical instrumentation or interconnection facilities, as described in Australian Patent No. 726349. As shown in  FIGS. 1 ,  6  and  7 , the tip of an optical fibre  14  is fixed within the connector assembly  10  by a ferrule  16  that provides precise physical positioning of the fibre  14 . The ferrule  16  is normally cylindrical with an outer diameter of 2.5 mm and an inner diameter that matches the outer diameter of the fibre  14 , which is normally about 125 microns. As shown in  FIG. 1 , the ferrule  16  is supported by an inner sleeve  18  and an outer sleeve  20  of the SC connector assembly  10 . The outer sleeve  20  is held within the support  12  so as to provide a recess  22  around the outer sleeve  20 . The fibre cable that would normally be seen projecting from the rear of the connector assembly  10  has not been shown for clarity. 
   As shown in  FIGS. 2 ,  9  and  10 , the recess  22  allows a through connector  24  to be connected to the connector assembly  10  so as to engage with the ferrule  16  and the inner sleeve  18  to secure the through connector  24  to the connector system. As shown in  FIG. 9 , two locking arms  26  laterally disposed about an alignment sleeve  27  within the through connector  24  lock onto locking tabs  64  on the inner sleeve  18  as the through connector  24  is pushed into the recess  22 . The through connector  24  cannot be removed from the connector system by pulling on the fibre cable or the through connector  24  without damaging the connectors  10 ,  24 . The through connector  24  can only be safely removed from the connector system by depressing a release arm  28  and pulling the through connector  24  away from the connector system, as described below. The securing of the through connector  24  and the optical connector system prevents accidental disconnection when the cable or fibre is accidentally pulled. Similar features to prevent accidental disconnection are provided by a number of alternative connectors. 
   A through connector that is used to connect two optical connectors of different types is referred to as a through adaptor, an inter-series adaptor, or an inter-series through adaptor. For example, the through connector  25  illustrated in  FIG. 2  is a through adaptor for interconnecting an ST optical connector and an SC optical connector. 
   As shown in  FIG. 3 , the connector assembly  10  is retained within the support  12  by connector assembly locking tabs  29  that engage with walls of openings  32  in the sides of the support  12 . The connector assembly locking tabs  29  project from the outer surfaces of two resilient connector assembly release arms  30  of the connector assembly  10 . The connector assembly  10  can be removed from the support  12  by squeezing the resilient connector assembly release arms  30  towards each other and withdrawing the connector assembly  10  from the rear opening of the support  12 . 
   As shown in  FIG. 4 , the support  12  is part of a support assembly  13  that further includes a support face plate  36  arid a support locking plate  38 . The support locking plate  38  is a resilient metal plate in the shape of a platform with oblique projecting arms  40  that engage with ridges  42  formed along the outer sides of the support  12  to secure the support  12  against the support face plate  36 . 
   As shown in  FIG. 5 , the connector assembly  10  includes the outer sleeve  20 , and an inner sleeve assembly comprising an inner sleeve  46  and an inner sleeve locking assembly  48 . The inner sleeve locking assembly  48  includes an inner sleeve locking support  50 , and an inner sleeve locking nut  52 . The inner sleeve locking support  50  includes an inner sleeve locating recess  56 , a locking sleeve  58 , and the release arm  28 . 
   The inner sleeve  46  is a standard SC optical connector inner sleeve that supports the ferrule  16  and is connected to a boot  54  at the rear. The boot  54  slides through an opening and locating recess  56  in the inner sleeve locking support  50  to nest within the locking sleeve  58 . The locking sleeve  58  has a threaded outer surface which mates with the inner thread of the inner sleeve locking nut  52 . As shown in  FIG. 6 , a raised annular portion  61  around the outer surface of the locking sleeve  58  causes the end of the locking sleeve  58  nearest the boot  54  to be forced radially inwards to clamp the boot  54  as the inner sleeve locking nut  52  is screwed onto the locking sleeve  58 . As shown in  FIG. 5 , two longitudinally disposed slit openings  59  in this end of the locking sleeve  58  facilitate this clamping action. Accordingly, the inner sleeve  46  and the inner sleeve locking assembly  48  are secured together to form an inner sleeve assembly, as shown in  FIG. 7 . 
   The connector assembly  10 , as shown in  FIG. 8 , can then be formed by sliding the inner sleeve  46  of the inner sleeve assembly within an opening  62  in the outer sleeve  20 . The front portion  63  of the outer sleeve  20  is the same shape as a standard SC outer sleeve and incorporates standard SC connector release features, as described below. This allows the connector assembly  10  to connect to the standard SC through connector  24 , and for the through connector  24  to be subsequently released by sliding relative movement of the inner sleeve  46  and the outer sleeve  20 . 
   As the through connector  24  is pushed onto the connector assembly  10 , the resilient arms  26  within the through connector  24  are deformed around the inner sleeve locking tabs  64  as they slide over the tabs  64 . Once past, the arms  26  snap back into position and lockingly engage with the tabs  64  to prevent accidental removal of the through connector  24 . In order to release the through connector  24 , the inner sleeve  46  is slid forward relative to the outer sleeve  20 , so that the sloping tab release guides  66  in the outer sleeve  20  lift the through connector arms  26  away from the inner sleeve locking tabs  64  to release the through connector  24 . This requires relative movement of the inner sleeve  46  and the outer sleeve  20 . However, the outer sleeve  20  is held in place by the connector assembly locking tabs  29 , and the inner sleeve  46 , being secured within the inner sleeve locking assembly  48 , is held in place by the engagement of a connector release locking tab  60  of the resilient connector assembly release arm  28  against a retaining edge  68  of the support  12 , as shown in  FIG. 10 . Thus, the through connector  24  cannot be removed from the connector assembly  10  without damaging the connectors unless the resilient connector assembly release arm  28  is depressed to disengage the connector release locking tab  60  from the retaining edge  68 . This releases the inner sleeve assembly and allows it to slide away from the outer sleeve  20  when the through connector  24  is pulled away from the connector assembly  10 , thus disengaging the through connector arms  26 , as described above. The sliding movement is stopped when a front wall  70  of the inner sleeve locking support  50  meets with the rear wall  72  of the outer sleeve  20 . However, the degree of relative movement of the outer sleeve  20  and inner sleeve  46  thus achieved is sufficient to release the through connector  24 , as described above, which can then be removed from the connector assembly. 
   Many modifications will be apparent to those skilled in the art without departing from the scope of the present invention as herein described with reference to the accompanying drawings. For example, although the preferred embodiment of the connector assembly has been described in terms of SC optical connector components, it will be apparent that alternative embodiments could be based on alternative connector types, such as LC or MU connectors.