Patent Publication Number: US-2012039573-A1

Title: Connector

Description:
INTRODUCTION 
     The invention relates to connectors for communication of signals to and from circuit boards. 
     It is well known to provide an electrical socket, adapted for use with an appropriate plug, to allow equipment to be connected to an electrical cable. One common type of socket is the “RJ45” socket, shown in  FIG. 1 , in which the socket includes a cavity  2  to receive a matching plug. Spring contacts protrude into the cavity, located so that when the plug is inserted they will make electrical contact with corresponding strips of metal in the plug. These spring contacts are connected to pins which protrude from the bottom of the socket to allow electrical connection to the equipment in which the socket is mounted. 
     It is also known to provide an optical connector, for example that described in our published specification number WO 2007/148315. 
     The invention is directed towards providing for more versatility in connecting optical and/or electrical signal cables to devices. 
     SUMMARY OF THE INVENTION 
     According to the invention, there is provided a connector comprising:
         an electrical socket,   an optical socket, and   a communication channel for transferring signals from the sockets to a host device.       

     In one embodiment, the communication channel comprises electrical conductors. 
     In one embodiment, the conductors are in a single backplane or lead. 
     In one embodiment, the connector further comprises an electro-optical component linked between the optical socket and the communication channel. 
     In one embodiment, the connector further comprises a switching means to provide a signal on the communication channel indicating which socket is providing data signals. 
     In one embodiment, the switching means is operated by insertion of an electrical plug into the electrical socket. 
     In one embodiment, the switching means is operated by insertion of an optical fibre into the optical socket. 
     In another embodiment, said switching means is adapted to provide either or both of:
         a. an external signal fed out of the connector to indicate the presence or absence of said electrical plug or said fibre, and/or   b. switching of signals within the connector.       

     In one embodiment, the switching means comprises a spring contact element arranged to be in contact with another electrical element inside a socket in the absence of a plug, so that when a plug is inserted the spring contact element is moved to come into contact or to be no longer in contact with said other electrical element. 
     Preferably, the switching spring contact also serves as a spring contact which can make contact with an appropriate conductive part of a plug when it is inserted. 
     In one embodiment, the switching means comprises a switch operable by being pressed upon by a part of an inserted plug which does not have an electrical contact. 
     In one embodiment, said switch is compatible with switches operated by a conductive part of the plug, so that both sets of switches may be formed by substantially the same manufacturing process. 
     In one embodiment, the connector further comprises a moving element, actuated by the insertion of a plug, which is adapted to move at least one spring contact element so as to break electrical circuit between it and another element within the connector before said spring contact makes electrical contact with any part of said plug. 
     In one embodiment, the elements are mounted so that relative movement causes wiping of the elements against each other when they are coming into contact. 
     In one embodiment, an element is a cantilevered spring element, a free end of which slides in a groove within which the other element is located in an offset position. 
     In one embodiment, the communication channel further comprises circuit elements including capacitors so that the communication channel is connected for AC signals only to electro-optical elements. 
     In one embodiment, the communication channel further comprises circuit elements including inductors so that electrical contacts for making contact with a plug are isolated from the communication channel. 
     In one embodiment, a set of external electrical contacts for the communications channel are routed internally to be connected either electrically by means of a plug inserted into a socket in the connector, or optically by means of optical fibres held in proximity to electro-optical devices by an optical socket gripping mechanism. 
     In another embodiment, the communication channel is adapted to provide signals to a mother board which are identical to those that would be presented by a conventional electrical connector. 
     In one embodiment, the connector further comprises means to prevent the insertion of an optical fibre if an electrical plug is inserted into the electrical socket, and to prevent insertion of an electrical plug if an optical fibre is present in the optical socket. 
     In one embodiment, the prevention means comprises a sliding or rotating element which blocks access to one of the sockets at any one time. 
     In one embodiment, a socket comprises an insert for insertion in another socket. 
     In one embodiment, the electrical socket also includes electro-optical devices arranged so that, by the insertion of the insert, it may be used for an optical connection. 
     In one embodiment, the optical socket comprises a pair of fibre sockets each adapted to receive a fibre termination, and each fibre socket comprises a resilient wall facing the other fibre socket and configured so that a clamp pressed between the fibre sockets causes the fibre sockets to grip an inserted fibre. 
     In one embodiment, the connector further comprises a clamp adapted to be inserted between the fibre sockets to cause them to grip fibres. 
     In another aspect, the invention provides an insert adapted for use with any socket as defined above. 
     In one embodiment, the insert comprises an insert body and a clamp, such that movement of the clamp relative to the body of the insert can grip or release optical fibres in the body of the insert. 
     In one embodiment, the insert comprises a sprung latch to retain it within the socket after it has been inserted. 
     In one embodiment, the insert includes a lever to release the sprung latch so that it can be removed, if required, from the socket. 
    
    
     
       DETAILED DESCRIPTION OF THE INVENTION 
       The invention will be more clearly understood from the following description of some embodiments thereof given by way of example only with reference to the accompanying drawings in which; 
         FIG. 1  is a cross sectional view of a prior-art RJ45 socket as described above; 
         FIG. 2  is a side cross-sectional view of a connector of the invention; 
         FIG. 3  is a front view of another connector; 
         FIG. 4  is a circuit diagram of a circuit of the connector; 
         FIG. 5  is a detailed cross-sectional view showing a slot of a back wall of a cavity of the connector; 
         FIG. 6  is a cross-sectional view of a connector of the invention, incorporating a flap for movement upon insertion of a plug; 
         FIG. 7  is a cross-sectional view of a connector of the invention, incorporating an auxiliary connector; 
         FIG. 8  is a circuit diagram of the connector shown in  FIG. 7 ; 
         FIGS. 9 to 12  are cross-sectional views of alternative connectors of the invention, and 
         FIGS. 13 and 14  are perspective and cross-sectional plan views showing an alternative optical part of a connector. 
     
    
    
     A double connector has one part which provides an electrical connection and another part providing an optical connection. A single set of pins connects the connector to its circuit. The connector includes a circuit allowing a channel of communication on a motherboard to be connected either electrically or optically, according as the user of the equipment may choose. Additionally, a signal may be provided back to the motherboard to indicate which means of connection is employed. The double connector may be arranged so that if a (for example, lower cost) piece of equipment is required without an optical interface, then a conventional electrical connector may be fitted in the same place without change to the motherboard. 
       FIG. 2  shows a simplified cross section through a connector  20  according to the invention, which has a mechanism  21  to receive and hold in place optical fibres, and a socket  22  to receive an electrical plug. A printed circuit board  26  is fitted with pins  24  to allow connections to be made to a motherboard. The electrical contacts  23  connect the appropriate points on the printed circuit board to the electrical plug, when it is inserted. Opto-electrical components  29  have their leads connected to the printed circuit board  26 , so that when optical communication is required the signals can pass through these components. Short pins  28  are mounted on the printed circuit board  26  approximately in-line with some of the contacts  23  and in such a position that the ends of the contacts  23  touch the corresponding pins  28  when there is no electrical plug in the cavity. Other electronic components  27  as required are also mounted on the printed circuit board  26 . 
       FIG. 3  shows a front view of a connector  30 . In this view the connector  30  includes two holes  31  for the insertion of optical fibres, and a cavity  32  for the insertion of an electrical plug. Within this cavity can be seen a row of eight contact elements  33  which make contact with corresponding portions of the plug when it is inserted. An additional similar element  36  is mounted in a position where there is no corresponding contact on the plug. The tips of the elements  33  and  36  move up and down in slots formed in the back wall of the cavity  32 . When there is no plug inserted, some of these contacts rest on the bottoms of the slots in which they move. Others, including the element  36 , rest on the tips of short switch pins  38  which are projecting into the back wall from the printed circuit board that is behind this wall. Pins  34 , and pegs  35 , allow the connector to be mounted on a motherboard in equipment of which it is to form part. The pins  34  connect the electrical signals to the motherboard and the pegs  35  provide mechanical anchorage. 
       FIG. 4  is a circuit diagram of the connector  30 . Pin numbers  101  through  108  are for connection to the motherboard and pin numbers  121  through  128  are for the electrical plug. Pin number  129  identifies a contact-like element mounted to the side of the electrical socket part, where it will make only mechanical contact with the plug. Thus pins  101  to  108  in  FIG. 4  correspond to pins  34  in  FIG. 3 , pins  121  to  128  in  FIG. 4  correspond to pins  33  in  FIG. 3 , and pin  129  in  FIG. 4  corresponds to pin  36  in  FIG. 3 . 
     In  FIG. 4 , item  131  identifies an opto-electrical receiver assembly, and number  132  identifies the opto-electrical transmitter assembly. The five switches  133  are formed by the tips of the corresponding contact or contact-like elements touching the corresponding pins projecting from the printed circuit board. In the diagram they are shown in their closed positions, i.e. when there is no plug in the cavity. The six capacitors and two resistors shown in the circuit diagram are mounted on the printed circuit board within the connector. It can be seen that the main communication circuits Tx+, Tx−, Rx+ and Rx− are connected to the appropriate pins of the opto-electrical subassemblies when the electrical plug is not present, and are connected to the electrical plug and not to the optical elements as soon as the plug is inserted. The pin  107  is connected to ground when the plug is absent, and is disconnected when the plug is inserted, so providing a signal back to the circuits mounted on the motherboard to indicate which type of connection is in use. 
       FIG. 5  shows in more detail a part  40  of the back wall of the cavity  32  shown in  FIG. 3  provided for the electrical plug. One of a number of slots  41  is shown. At the bottom of the slot, slightly offset from the axis of the slot, is a switch pin  42 . When released by the removal of the electrical plug, the tip of the contact moves down the slot through positions  43  and  44  until coming to rest in position  45 . The sliding action of the contact moving around the pin from position  44  to position  45  will provide a wiping action, so cleaning the surfaces of both components and promoting good electrical contact. 
     With the arrangement as shown in  FIG. 2 , during the insertion of the plug, there could be a momentary electrical connection between the electrical contact of the plug and the contact element  23  while the contact element  23  was still in contact with the switch pin  28 . This would occur when first contact was made between the plug and the contact, and before the contact was lifted sufficiently to open the switch. If this momentary contact is to be avoided, a mechanical flap  51  can be fitted as shown in  FIG. 6 . In this drawing the combined connector  50  is generally as already described, but there is additionally the flap  51  pivoted within the housing of the connector. As shown by the dotted lines, when there is no plug in the cavity, the flap  51  can move away from the electrical contact  53 , and allow the electrical contact  53  to rest on, and make electrical contact with, the switch pin  54 . When the plug is inserted a small distance into the cavity, the flap  51  is forced into the position shown by the solid lines, and lifts the contact  53  to the position shown by solid lines, so that the electrical circuit between the contact  53  and the switch pin  54  is broken before the plug can make an electrical circuit with the contact  53 . 
       FIG. 7  is a cross sectional view through a connector  60 , similar to that shown in  FIG. 2  and like parts are assigned the same reference numerals. The connector  60  has an additional auxiliary connector  61 . In this embodiment, as in  FIG. 2 , there is a mechanism  21  to receive and hold in place optical fibres and a socket  22  to receive an electrical plug. A printed circuit board  26  is fitted with pins  24  to allow connections to be made to a motherboard. The electrical contacts  23  connect the appropriate points on the printed circuit board to the electrical plug, when it is inserted. The opto-electrical components  29  have their leads connected to the printed circuit board  26 , so that when optical communication is required the signals can pass through these components. Short switch pins  28  are mounted on the printed circuit board  26  and project through the back wall of the cavity  22  approximately in-line with some of the contacts  23 . As described with reference to  FIG. 5 , these are positioned so that the ends of the contacts touch the corresponding pins  28  when there is no electrical plug in the cavity. Other electronic components  27  as required are also mounted on the printed circuit board  26 . In addition, a set of pins  61  form an auxiliary connector. With this arrangement the pins  24  can all have the same printed circuit board connections as would be the case if an electrical connector only were to be fitted, and the additional connections required for the combined connector (for example, a power supply for the optical components) can be made by a cable within the equipment connected to the auxiliary connector. 
       FIG. 8  is circuit diagram of the connector shown in  FIG. 7 . Numbers  101  through  108  refer to the eight pins provided for connection to the motherboard. Numbers  121  through  128  refer to the eight contacts for the electrical plug. Number  129  identifies the contact-like element mounted to the side of the electrical socket part, where it will make only mechanical contact with the plug. Numbers  71  to  74  identify additional pins provided on the auxiliary connector  61 . It can be seen that the main communication circuits Tx+, Tx−, Rx+ and Rx− are connected to the appropriate pins of the opto-electrical sub-assemblies when the electrical plug is not present, and are connected to the electrical plug and not to the optical elements as soon as the plug is inserted. Pins  104 ,  105 ,  107  and  108  are connected to the pins  124 ,  125 ,  127  and  128  as would be the case in a simple electrical connector. A power supply for the connector is provided by means of the pins  73  and  74  on the auxiliary connector  61 , and the signals identified as “Mode” and “SD” are available on this connector if they are required to be connected within the equipment. 
     Referring to  FIG. 9 , a connector  80  has an element  85 , which is a slider to prevent an optical fibre from being inserted while an electrical plug is still in place and vice-versa. When the slider  85  is in an upper position as shown, a clamp  86  for holding the fibre in place cannot be closed, and elements of the sliding portion can pass between the passages in the clamp and the passages in the rest of the optical part of the connector, to prevent a fibre from being inserted (conversely, the slider cannot be lifted into the position shown if a fibre has already been inserted). If the sliding portion  85  is moved down, then it blocks the entrance to the electrical part of the connector, so that a plug cannot be inserted (and, again, the slider  85  cannot be moved down if a plug is already in position). Instead of the sliding mechanism shown, the same purpose could be accomplished by a rotating element within the connector, so shaped and pivoted that in one position a part of it projects into the cavity to prevent the electrical plug being inserted, and in the other position a part of it projects into the path of the optical fibre. If neither fibre nor plug were present, the slider would be free to move, and could be moved out of the way by the insertion of either fibre or plug. However, once one is inserted, it would have to be removed before the other could be inserted. 
     Another embodiment is shown in  FIG. 10 , in which a connector system  90  comprises a socket  91 , an insert  93  and a clamp  94 . The connector  91  is shown here mounted on a motherboard  92  of a piece of equipment of which it forms part. 
     The socket  91  is shown in more detail in  FIG. 11 , in which it can be seen to include a housing  95 , in which there is formed a cavity  96 . Electrical contacts  97  project into this cavity. These electrical contacts are attached to a printed circuit board  98  internal to the socket. Within the housing  95  there are one or more electro-optical devices  99 : These are electrically connected to the internal printed circuit board  98  and are mounted close to the back of the cavity  96 . Holes in the back wall of the cavity permit access to the optical portions of these devices from the cavity. The printed circuit board  98  carries the necessary circuits to connect the electrical contacts and the electro-optical devices to the motherboard  92  of the equipment in which the socket is mounted. An internal step  100  within the cavity provides a location for a latch mechanism to retain a plug or insert within the socket. 
     If electrical connection is desired, it will be appreciated that the cavity  96  and the electrical contacts  97  allow this socket to function as a normal electrical socket, receiving a plug (not shown) and making an electrical connection in the usual way. 
     If, on the other hand, an optical connection is required, the insert  93 , assembled with the clamp  94 , may be inserted into the socket  91  to adapt it for optical connections.  FIG. 12  shows the insert  93  and the clamp  94  assembled together. The insert  93  may be moulded as a single piece, adapted in shape for fitting into the cavity  96  of the socket. The insert includes a latch  131  adapted to engage in the internal step  100  of the socket cavity. A lever  132  allows this latch to be disengaged if it is desired to remove the insert from the socket. The front end of the insert has features  133  designed to align the insert accurately with the electro-optical devices  99 , either by engaging directly with features on the electro-optical devices, or by engaging with features on the back wall of the cavity, in which case the back wall of the cavity should also have features to align it accurately with the electro-optical devices. The insert also includes one or more broadly cylindrical features  134 , which are split lengthwise over part of their length. These cylindrical features carry a cylindrical passage  135 , suitable to guide an optical fibre, or an optical fibre surrounded by a cylindrical jacket. The alignment features  133  and the passage  135  are so arranged that a fibre introduced through the passage will be aligned with the optical axis of the electro-optical device  99 . 
     The clamp  94  also includes one or more cylindrical passages  136  suitable for guiding an optical fibre, so that a fibre may be introduced into the clamp and passed through it into the passage  135  in the insert  93 . The clamp  94  also includes elements  137 , which may be tapered or wedge shaped over part of all of their length, and which are adapted to slide beside or between the cylindrical portions  134  of the clamp. After it has been assembled with the insert, the clamp is still capable of movement within the insert along the axis of the cavities,  135  and  136 . The insert and clamp include guiding surfaces (not shown in detail) to keep the axis of the clamp aligned with the axis of the insert, and a catch mechanism (not shown) to limit the movement of the clamp so that it cannot easily be removed from the insert after they have been assembled together. When the clamp is moved further into the insert, the elements  137  serve to squeeze the cylindrical features  134  of the insert in the area in which they are split, so as to squeeze the two sides together, and grip the optical fibre which has been inserted. 
     Thus to make an optical connection to the socket, the user may insert the insert-clamp assembly into the socket until it is correctly located and retained in position by the latch; They then ensure that the clamp is in its open position, where it is not squeezing the cylindrical elements of the insert. They then insert one or more optical fibres through the passages in the clamp, which passages guide the fibres into the passages in the insert. The user keeps inserting the fibres until they make contact with the electro-optical elements. Then the user pushes in the clamp, so squeezing the cylindrical portions of the insert to grip the fibre and retain it in place. 
     To remove the optical connection, the user has two choices: They may pull back the clamp without removing it from the insert, so releasing the fibre, but leaving the insert in the socket; or they may release the insert from the socket by operating the lever  132 , and remove the insert, complete with the clamp and the optical fibre, from the socket. 
     Referring to  FIGS. 13 and 14  the optical part of the connector may comprise a housing  150  having two sockets  151  and  152  in a moulded plastics frame  153  for receiving optical fibres. A clamp  160  has a central clamp member  161  which slides between the two sockets  151  and  152  to cause them to press against a fibre due to a wedging effect. The clamp  13  has through holes  163  for receiving the fibres, and snap-fitting lugs  164 . 
     The invention is not limited to the embodiments described but may be varied in construction and detail.