Patent Publication Number: US-7722367-B2

Title: Apparatus for distributing electrical power and/or communication signals

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     The present application is a divisional application of pending U.S. patent application Ser. No. 11/682,143, filed on Mar. 5, 2007, which is a Divisional Application of U.S. patent application Ser. No. 10/510,965, filed on Nov. 1, 2004, now U.S. Pat. No. 7,201,589, which is the National Stage of International Application PCT/SG03/00100, filed on Apr. 30, 2003. 
    
    
     BACKGROUND AND FIELD OF THE INVENTION 
     This invention relates to apparatus for distributing electrical power and/or communication signals more particularly to an apparatus enabling an electrical power supply and/or communication signals to be provided to an electrical power or communication point respectively. 
     Communication signals are used in a wide sense in this application to include voice, data, text, image and/or video be it transmitted point-to-point or point-to-multipoint. 
     The conventional system of electrical power distribution in domestic and commercial environments is provided by power points which are installed in a wall cavity or a surface mounted power outlet at predetermined places. The location of such power points needs to be chosen in advance and often subsequent requirements can mean that the power points are provided in the wrong location and/or in insufficient numbers. 
     A similar disadvantage is also present for communications points used to distribute voice, data or text, for example. 
     It is an object of the invention to provide a more flexible apparatus for distributing electrical power and/or communication signals. 
     SUMMARY OF THE INVENTION 
     According to the invention in a first aspect, there is provided electrical power supply distribution apparatus comprising a conduit containing at least one elongate conductor, the conduit having an opening through which a connector is able to be inserted to connect electrically with the conductor; and a conductive member disposed between the opening and the conductor and resiliently displaceable by a said connector to provide access to the conductor. 
     Preferably, the member forms an earth connector and is resiliently biased towards and/or occludes and/or seals the opening and the apparatus may further comprise a displaceable flap for the opening, the member underlying the flap. 
     The apparatus may be combined with a said connector having an electrical contact arranged to engage the conductor. 
     According to the invention in a second aspect, there is provided electrical power supply distribution apparatus comprising a conduit containing at least one elongate conductor, the conduit having an opening arranged to receive a connector to connect electrically with the conductor; and a cable run separated from the conductor by an EMI shield. 
     The shield is preferably formed by at least a part of the conduit and may be formed from metal or as a metallic or metallised layer. The shield may form an earth connector. Preferably the cable run is arranged to receive data and/or communications cables. 
     According to the invention in a third aspect, there is provided an electrical connector arranged to receive an electrical plug and having first and second electrical contacts arranged to engage corresponding conductors of an electrical power supply distribution apparatus, wherein the contacts are disposed at opposed ends of an arm rotatable between a first position in which the contacts are arranged to disengage from the conductors and a second position in which the contacts are arranged to engage with the conductors. 
     According to the invention in a fourth aspect, there is apparatus for distributing electrical power and/or communication signals which comprises an elongate conduit containing at least one elongate conductor, the conduit having an elongate opening arranged to receive a connector to connect electrically with the conductor and a resiliently displaceable flap for the opening wherein the flap is co-extruded with a part of the conduit. 
     Preferably the or each flap is co-extruded with a member forming a side of the opening. The flap and part of the conduit may be co-extruded from the same material but of different hardness. Alternatively, the flap and part are co-extruded from different materials. 
     According to the invention in a fifth aspect, there is provided a terminal connector arranged to engage a conduit containing at least one elongate conductor and having an opening arranged to receive a power point connector or an electrical plug to connect electrically with the conductor, the terminal connector having means slidably connectable to an end of a said conduit and to said conductor and arranged to connect the conductor to a mains supply or the conductor of another said conduit. If the conduit carries at least a further conductor to distribute data and/or communication signals, then a data and/or communications terminal connector is used to connect to an end of a said conduit and to the further conductor and arranged to connect the further conductor to a data and/or communications cable for providing communication signals. 
     Preferably, two connectors of the fifth aspect may be combined and connected together so that said means project outwardly so as to be connectable to adjacent said conduits. 
     According to the invention in a sixth aspect there is provided electrical power distribution apparatus comprising: a metal conduit containing at least one elongate conductor, the conduit having an opening arranged to receive a connector to connect electrically with the conductor; and the conductor being connected to the conduit via an insulator, whereby the conduit forms an EMI shield for the conductor. 
     In a variation of the third aspect, an electrical plug may be arranged to be coupled directly with an electrical power supply distribution apparatus which forms an independent seventh aspect of the present invention and which provides an electrical plug arranged to receive one or more electrical wires for coupling to an electrical device, the plug having first and second electrical contacts arranged to engage corresponding conductors of an electrical power supply distribution apparatus, wherein the contacts are disposed at opposed ends of an arm rotatable between a first position in which the contacts are arranged to disengage from the conductors and a second position in which the contacts are arranged to engage with the conductors. 
     According to the invention in an eighth aspect, there is provided communications signal distribution apparatus comprising a conduit containing at least one elongate conductor, the conduit having an opening arranged to receive a data and/or communications connector to connect electrically with the conductor. In this way, the apparatus is arranged to distribute voice, data, text to an communications device connected to the connector. 
     According to the invention in a ninth aspect, there is provided apparatus for distributing electrical power and/or communication signals, the apparatus comprising two conduits separated by an EMI shield, each conduit containing at least one elongate conductor and which includes an opening arranged to receive a conductor to connect electrically with the conductor. 
     Preferably, one conduit is used to distribute voice, data or text and the other conduit is used to distribute electrical power. If one of the conduit is used to distribute electrical power, then the apparatus further comprises a conductive member in the conduit which is being disposed between the opening and the conductor of the conduit and being resiliently displaceable by a the connector to provide access to the conductor of the conduit. 
     According to the invention in a tenth aspect, there is provided an electrical socket comprising a housing containing at least one conductor, the housing having an opening through which a connector is able to be inserted to connect electrically with the conductor, and a conductive member disposed between the opening and the conductor and resiliently displaceable by a said connector to provide access to the conductor. 
     According to the invention in a eleventh aspect, there is provided an extension cable including the invention(s) of any of the preceding aspects. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Embodiments of the invention will now be described by way of example with reference to the accompanying drawings in which: 
         FIG. 1  is a three dimensional view of a track of a first embodiment of power supply apparatus of the invention; 
         FIG. 2  is an enlarged view of a track section of the embodiment of  FIG. 1  showing a power point connector connected to the track section; 
         FIG. 3  is a view of the track section in direction of the arrow A of  FIG. 2 ; 
         FIG. 4  is an underneath three-dimensional view of the track section of  FIG. 2 ; 
         FIG. 5  is an exploded perspective view of part of the track section of  FIG. 2 ; 
         FIG. 6  is an underneath view of the earth spring of  FIG. 5 ; 
         FIG. 7  is a cross-sectional view similar to  FIG. 3  of a track section of a second embodiment of the invention; 
         FIG. 7   a  is a cross-sectional view of a variation of the second embodiment shown in  FIG. 7  and which forms a third embodiment of the invention; 
         FIG. 8  is an exploded perspective view of the power point connector shown in  FIG. 2 ; 
         FIG. 9   a  is an assembled view of the connector of  FIG. 7  in the first position in which connector is inserted into the slot in the track section and  FIG. 9   b  being a similar view of the connector in a second position where the connector engages electrical conductors and earth spring of the track section which are also shown. 
         FIG. 10  is a part-section perspective view of the track section and power point connector, with the connector having been inserted into the track section; 
         FIG. 11  is a view similar to  FIG. 10  showing the power point connector rotated to engage the electrical conductors of the track section; 
         FIG. 11   a  shows a bottom perspective view of another variation of a power point connector; 
         FIG. 11   b  shows an exploded view of part of the power point connector of  FIG. 11   a;    
         FIG. 11   c  shows the components of the power point connector depicted in  FIG. 11   b  being assembled together; 
         FIG. 12  is a perspective view of a terminal connector unit which is arranged to connect the track sections to an electricity supply; 
         FIG. 13  is an exploded perspective view of the unit of  FIG. 12 ; 
         FIG. 14  illustrates a casing for the terminal connector unit; 
         FIG. 15  shows the terminal connector unit engaged with the track section; 
         FIG. 16  illustrates a 180 degree joint used between track sections; 
         FIG. 17  shows a 90 degree joint; 
         FIG. 18  shows a 270 degree joint; 
         FIG. 19  shows a communications socket cover; 
         FIGS. 19   a  and  19   b  show different perspective views of a variation of a power supply/connection unit; 
         FIG. 20  shows an electrical plug which can be used to connect directly to the track section of  FIG. 1  without using the power point connector of  FIG. 8 ; 
         FIGS. 20   a  and  20   b  shows different perspective views of an internal structure of the electrical plug of  FIG. 20 ; 
         FIG. 21  shows a bottom perspective view of the electrical plug of  FIG. 20  illustrating a contact arm with ends covered by two protection members; 
         FIG. 22  shows the same view of  FIG. 21  with the contact arm rotated; 
         FIG. 23  shows an exploded perspective view of an electrical socket which can be used to receive the power point connector of  FIG. 8  or the electrical plug of  FIG. 20 ; 
         FIG. 23   a  shows a rear perspective view of the electrical socket of  FIG. 23  being arranged to receive a variation of an electrical plug of  FIG. 20  and which is attached to three electrical wires; 
         FIG. 23   b  shows a bottom view of the electrical socket of  FIG. 23  illustrating three cavities for receiving the electrical wires of  FIG. 23   a.    
         FIG. 24  shows a perspective view of the plug of  FIG. 23   a  with the contact arm rotated to engage two conductive terminals of the electrical socket of  FIG. 23 ; 
         FIG. 25  shows a cross-sectional side view of the track section of  FIG. 7   a  adapted to distribute communication signals; 
         FIG. 26  shows a three dimensional view of the track section of  FIG. 25 ; 
         FIG. 27  shows a front perspective view of a data and/or communications connector for use with the track section of  FIG. 25  for distributing communication signals; 
         FIG. 28  shows a rear perspective view of the data and/or communications connector of  FIG. 27 ; 
         FIG. 29  shows a cross-sectional view of the data and/or communications connector of  FIG. 27 ; 
         FIG. 30  shows a cross-sectional view of the data and/or communications connector of  FIG. 27  connected to the track section of  FIG. 25 ; and 
         FIG. 31  shows a front view of a variation of the data and/or communications connector of  FIG. 27 ; 
         FIG. 32  shows a perspective view of the track section of  FIG. 25  connected to a data and/or communications connector and terminal connector; 
         FIG. 33  shows an exploded view of the data and/or communications terminal connector of  FIG. 32 ; 
         FIG. 34  shows an assembled view of the terminal connector of  FIG. 32 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     With reference to  FIGS. 1 and 2 , general views of the elements of an embodiment of the apparatus of the invention are shown. The apparatus provides a means for selecting a position in which power points may be placed thus allowing flexibility in position and/or number of power points which may be provided. A track is shown in  FIG. 1  and comprises a plurality of identical track sections  100 , each having a slot  110 , connected together by means of joints  200 - 260  and end connectors  280 ,  300 . Within the connectors  200 - 300  are provided power supply/connection units described hereafter which connect the track as a whole to the electrical mains supply and provide electrical continuity between track sections  100 . Joint  240  also provides an interface to data and/or communication cables which run through the track as will be described below. At any point along slots  110 , one or more power point connector(s)  400  may be engaged with a track section  100  to provide a supply connection between the power supply connected to the track and a device to be plugged into the or each connector  400 . 
     With reference to  FIGS. 2-6  a track section  100  is shown in more detail and comprises a conduit formed from an elongate extruded plastics base  120  which includes cavities  122 ,  124  each for receiving an elongate cylindrical conductor  126 ,  128 , each cavity  122 ,  124  being provided with arcuate portions for engaging the sides of each conductor  126 ,  128  in a snap-fit arrangement. First and second cover members  130 ,  132  which clip to base member  120  via formations  134 ,  135 ,  136 ,  138 ,  139 ,  140  are also provided. The cover members  130 ,  132  together with portions  142 ,  144  of the base member  120  form elongate enclosures  146 ,  148  which provide cable runs. The cavities  122 ,  124  together meet in a central cavity  150  which has an opening forming the elongate slot  110 . The cover members  130 ,  132  are provided with elongate deformable plastic flaps  154  which provide a cover for the slot  110 . 
     An earth spring  160  formed from flexible, resilient conductive material is provided in the cavity  150 . The earth spring  160  is connectable to earth and has a flat, elongate, sheet-like central portion  162  with wings  164 ,  166  projecting arcuately away from the portion  162 . Each wing  164 ,  166  is divided into a plurality of wing members  168 ,  170  individually attached to the portion  162  as shown in  FIG. 6 . The wings  164 ,  166  rest in elongate slots  172 ,  174  which hold the ends of the wings in position. The surface  162  projects outwardly to cover slot  110  just below flaps  154 . The cavities  122 ,  124  further have projecting edges  176 ,  178  which engage the sides of wings  164 ,  166  and provide further support for the earth spring  160 . The earth spring  160  is locally resiliently displaceable from the position shown in  FIG. 2  to a position in which the central portion  162  is depressed downwardly to, in the limit, abut against a projection  152  of the base  120 . In this position, the ends of the wings  164 ,  166  remain in the elongate slots  172 ,  174 . The earth spring  160  in this position allows access to the electrical conductors  126 ,  128  by the power point connector  400 . 
     Each portion  142 ,  144  is provided with a plurality of openings  143  to allow fixing of the track section  100  to a supporting surface. The base further includes elongate channels  180 ,  182  for receiving connector lugs as will be described hereinafter. 
     The base  120  and covers  130 ,  132  are formed from extruded plastic materials, for example PVC or PP (Poly-propylene). The flaps  154  are co-extruded with the covers  130 ,  132  and are formed from the same material but of lower hardness. The cylindrical conductors  126 ,  128  are preferably formed from copper with the earth spring  160  being formed from a conductive spring material, preferably an alloy such as beryllium copper or phosphorous bronze. 
     A second embodiment of track section  100  is shown in  FIG. 7 . This is generally similar to that described with reference to  FIGS. 1-6  and similar parts have similar reference numerals with the addition of 1000. The essential difference between this embodiment and that of the previous figures concerns the base member  1180  which instead of being extruded from plastics material is extruded from metal, preferably aluminium. Each conductor  1126 ,  1128  is disposed in a cavity  1182 ,  1184  slightly differently shaped compared to the first embodiment via an elongate insulating member  1186 ,  1188 . The insulating members  1186 ,  1188  are extruded from PVC or PP and are a snap-fit in the cavities  1182 ,  1184 , held in place by co-operating formations ringed at  1190  and  1192 . Insulating member  1188  is shown snapped in place in cavity  1184  with member  1186  removed from the cavity  1182 . The insulating members  1186 ,  1188  have opposed jaws which hold the conductors  1126 ,  1128  in place. In use, the metal extrusion forming the base  1180  and the cavities  1192 ,  1194  provides an EMI shield between the conductors  1126 ,  1128  and the data and telecommunications cable runs  1146  and  1148 . The EMI shield is further enhanced by the wings  1164 ,  1166  of the earth spring  1160  which contact the metal base member  1180  at points  1194 ,  1196  to form a conductive loop around the conductor. The base member  1180  is preferably connected to earth as well as or instead of the earth spring  1160 , so that the combination of earth spring and base provides earth protection. 
     A third, preferred embodiment of the track section  100  is shown in  FIG. 7   a . This is generally similar to the second embodiment and similar parts have similar reference numerals with the addition of a further  1000 . The main difference between the second and third embodiments is the structure of the base member  2180  which is also extruded preferably from aluminium. Each conductor  2126 ,  2128  is disposed in a cavity  2182 ,  2184  slightly differently shaped compared to the second embodiment via an elongate insulating member  2186 ,  2188  which is also in a different form. The insulating members  2186 ,  2188  are typically made of the same material as the insulating members  1186 ,  1188  of the second embodiment and are a friction-fit in the cavities  2182 ,  2184 , held in place by opposing lugs  2200 ,  2202 ,  2204 ,  2206  engaging respective co-operating grooves  2208 ,  2210 ,  2212 ,  2214  in the insulating members  2186 ,  2188 . Each insulating member  2186 ,  2188  includes an elongate part cylindrical channel  2216 ,  2218  extending along the length direction of the insulating member  2186 ,  2188  so that the conductors  2126 ,  2128  are a sliding fit therein. The projecting edges  2176 ,  2178  are shaped differently from the previous embodiments and in this embodiment, the edges  2176 ,  2178  curved upwards towards the cover  2130  to engage the arcuate wings  2164 ,  2166  of the earth spring  2160 . The T-shaped projection  2152  extending from the base is also differently shaped at the ends. In use, the metal extrusion forming the base  2180  and the cavities  2182 ,  2184  provides an EMI shield between the conductors  2126 ,  2128  and the data and telecommunications cable runs  2146 ,  2148  similar to the second embodiment. The enhancement effect is also provided by conductive loops formed by the wings  2164 ,  2166  of the earth spring  2160  and respective contact points  2193 ,  2194 ,  2195 ,  2196 . 
     In a further variation, a plastic extrusion provided with a metal conductive film may be used for the second and third embodiments of the apparatus of the invention instead of a metal extrusion. In a further alternative, a plastic extrusion of a first embodiment may be used with a conductive paint or film covering the internal surfaces of the or each cable run  146 ,  148 . 
     The power point connector  400  shown in  FIG. 2  will now be described with more details with reference to  FIGS. 8 and 9 . The connector includes a cover  410  with openings  412 ,  414 ,  416  of a standard UK type three pin plug arrangement, although this, and the supporting mechanism, could be changed to any suitable plug/socket system. The cover  410  and a base  418  together form a housing. The base  418  has a generally circular opening  419  formed therein. A flange member  420  rests in the opening  419  held axially in place against the rim of the opening  419  by snap-fit catch  421  but rotatable relative to the rim. The flange member  420  has itself a circular opening  422  and is provided with radially inwardly extending contact protection members  424 ,  426  best shown in  FIG. 9 . 
     An electrical contact mounting member  430  is snapped on in opening  422 . The member  430  has a cylindrical bearing portion  432  connected to a larger cylindrical flange  434 . The bearing portion  432  rests in opening  422  with the flange  434  being supported by the edge of the opening. Connected to the bearing portion  432  is a contact arm  441  which is provided with contact holders  436 ,  438  at each end. The contact arm  441  is further provided with a raised section  435  extending only part of the length of the arm, offset relative to the axis of rotation of the arm. As shown in  FIG. 3 , in the second embodiment, the cavities  122 ,  124  are each provided with an inwardly projecting surface  156 ,  158  of a different length. The surfaces  156 ,  158  and projection  435  co-operate to allow only rotation of the arm  441  in one direction and not the other to ensure that a desired polarity of connection between the contact arm  441  and the conductors  126 ,  128  is maintained. 
     In the third embodiment of  FIG. 7   a , the rotation of the arm  441  is limited to one direction by the uniquely shaped projecting edges  2176 ,  2178  which are at different heights relative to the base  2180 . The thickness of the contact arm  441  would also be adapted such that one end is thicker than the other (not shown) so that the contact arm  441  can only rotate in one direction and prevented from rotating in another direction by the lower edge  2176 . 
     Each electrical contact holder  436 ,  438  is of a hook form, the tail of the hook being connected to the remainder of the arm  441  and the head being spaced from but resiliently displaceable towards the remainder of the arm. The length of the arm is such that when contact is made with the conductors  126 ,  128  there is a slide interference fit, so that the contact portions  436 ,  438  deform to give a pressing electrical contact. 
     The flange  434  provides a platform for a contact engaging formation  440  which holds live and neutral contacts  442 ,  444  in place. Each contact  442 ,  444  includes a pair of opposed arms  446 ,  448  which are arranged to receive a pin of a mains plug in sliding engagement when inserted through respective openings  414 ,  416 . Arms  446  are connected via a series of angular elements to contacts  450 ,  452  which engage around the outside of the contacts supporting portions  436 ,  438  as is best illustrated in  FIG. 9   b.    
     Earth connection  454  protrudes out of flange  434  and freely makes electrical contact with earth spring  160  once the power point connector  400  is pushed through slot  154 . In the embodiment of  FIG. 7 , the earth spring provides a bridge between the earth connection  454  and the aluminium base member  1180  which provides a further earth shield. 
     A shutter member  460  for closing off socket openings  414 ,  416  is provided. The shutter member  460  occludes the sockets  414 ,  416 , overlying the arms  446 ,  448  of the electrical contacts  442 ,  444 . The shutter member  460  has a spindle  462  which is received within a spring  464  which is in turn mounted between four orthogonal posts  466  of the mounting formation  440 . The shutter member  460  has slanting engagement surfaces  468 ,  470  which when a mains plug is inserted through sockets  414 ,  416  will cause shutter member  470  to rotate and be depressed away from the path of movement of the plug pins allowing the plug pins to engage with arms  446 ,  448  to make an electrical connection. 
     When assembled, the arm  441  projects through opening  422  and is rotatable between the position shown in  FIG. 9   a  in which the contacts  450 ,  452  are covered by protection members  424 ,  426 , and it is in this position that the connector  400  is inserted through slot  152  of track section  100 , and the position shown in  FIG. 9   b  after 90 degree clockwise rotation in which the contact member is at right angles to the protection members  424 ,  426 . It is in this position that the contacts  450 ,  452  engage with the conductors  126 ,  128 , with the protection members  424 ,  426  remaining in the slot  110  and locally depressing the earth spring  160 . 
     Operation of the embodiment of the invention will now be described with reference to  FIGS. 10 and 11  which are part section views, in  FIG. 10 , of the power point connector  400  when initially inserted into the track section  100  (see  FIG. 3 ) and, in  FIG. 11 , subsequently rotated clockwise, electrically to engage the conductors of the track section  100 . It is to be understood that the location at which the connector  400  engages the track is chosen by the user in accordance with requirements. Once this location is chosen, the connector  400  is placed in a position shown in  FIG. 9   a  with the protection members  424 ,  426  aligned with slot  110 . The connector  400  is then pushed through the cover  154  against the bias of the earth spring  160 , pressing this down at the point of entry of the connector  400 . The bias of the spring provides a resistance to entry and gives a feeling of positive location of the connectors in the slot to the user. Since the earth spring  160  is formed from flexible material, the spring resiliently deforms only at the point of entry of the connector  400  and remains in a position to cover slot  110  elsewhere. When fully depressed, the cover  410  is then rotated through 90 degrees. The cover, being connected to the rotatable member  430  also causes the arm  434  to rotate through 90 degrees so that this moves from a position in line with slot  152  to a position in which the arm  434  sweeps into cavities  122 ,  124  until the contacts  450 ,  452  engage conductors  126 ,  128  in sliding engagement to provide an electrical path between the conductors  126 ,  128  and the arms  446 ,  448 . The direction of rotation is dependent on which way the connector is inserted into the slot, since the offset projection  435  will strike surface  158  if the connector is turned the wrong way. Only when turned the right way will the projection  153  not strike the projecting surface  158 , thus only allowing connection of the contacts to the correct conductors. Flange member  420  remains in place during this rotation with contact protection members  424 ,  426  being held in the channel. The engagement of the arm  446 ,  448  with conductors  126 ,  128  and the sides of the adjacent cavities lock the power point connector  400  in place at the chosen location. The connector  400  may then be used by any normal electrical power point. 
       FIG. 11   a  shows a bottom perspective view of a variation of the power point connector  400 ′ of  FIG. 8 . In this variation, instead of a hook shape supporting portion at opposed ends of the contact arm  441 , a resiliently displaceable hemispheric contact or head  900 ,  902  is used which is shown more clearly in  FIG. 11   b.    
     The exploded perspective view of  FIG. 11   b  illustrates two heads  900 ,  902  resiliently displaceable in respective cylindrical holders  904 ,  906  which in turn are each connected to a series of angular elements  908 ,  910  that open up into contacts  912 ,  914 . Similar to the contacts  442 ,  444 , each contact  912 ,  914  includes a pair of opposed arms  916 ,  918  arranged to receive a pin of a mains plug in sliding engagement when inserted though respective openings  414 ,  416  (see  FIG. 8 ). When each head  900 ,  902  engages a respective conductor  2126 ,  2128 , using the third embodiment of the track section  100  as an example, electricity is conducted though the angular elements  908 ,  910 , contact  912 ,  914  and to the pin of the mains plug. 
     The earth connection is provided by another engagement surface  920  which protrudes out of the rotating arm  441  when assembled. The engagement surface  920  is electrically connected to another angular element  922  which also opens up to form a contact  924 . The contact  924  also has two oppose arms  926  resiliently biased together and is forced open when the earth pin of the mains plug is inserted between the two arms  926  such that the earth pin is in friction fit therewith. 
     The hemispheric heads  900 ,  902  and the engagement surface  920  are assembled in the housing of the contact arm  441  and  FIG. 11   c  shows this in more detail. As shown the heads  900 ,  902  and the engagement surface  920  protrudes out at different points of the contact arm  441  with the various contacts  912 ,  914 ,  924  facing outwards arranged to receive respective pins of a mains plug. When the connector  400 ′ is inserted through a slot  110  similar to that shown in  FIG. 9   a , the engagement surface  920  sits on the central portion  162  of the earth spring  160  and resiliently biases the central portion  162  towards the base  2180  (using the embodiment of  FIG. 7   a  as an example). In this way, electrical contact is formed between earth and the earth pin of the mains plug. 
     To engage the two conductors  2126 ,  2128 , the connector  400 ′ is similarly rotated 90 degrees (as shown in  FIG. 11   a ) so that the heads  900 ,  902  engage respective conductors  2126 ,  2128  which resiliently displace the heads  900 ,  902  inward of the cylindrical holders  904 ,  906 . Thus, electrical contact is made between the conductors  2126 ,  2128  and the respective neutral and live pins of the mains plug. 
     In one variation instead of a power point connector  400  which allows an electrical device to be connected to the track section  100 , the device may be wired directly to an electrical plug for direct connection to the track section  100  and  FIG. 20  shows an exploded view of an embodiment of the plug  750 . 
     The plug  750  includes a cover  752  and a ringed base  754  forming a housing. The cover  752  is attached to the base  754  via screws  756  through threaded holes  758  so that the cover  752  can be separated from the base  754  with ease. A cable  760  carrying three electrical wires  762 ,  764 ,  766  for “Earth”, “Neutral” and “Live” polarities of a power supply has one end connected to an electrical device and the other end connected to the plug  750 . Two elastomeric members  768  are disposed in the plug  750  near the entry of the cable  760  to resiliently hold the cable  760 . The three wires  762 ,  764 ,  766 , which are typically insulated, are stripped to expose a length of copper and attached to respective conductive terminals  770 ,  772 ,  774  using terminal screws  770   a ,  772   a ,  774   a . The terminals  770 ,  772 ,  774  are made of metal so that each wire  762 ,  764 ,  766  is electrically connected to each terminal  770 ,  772 ,  774  and are supported on a circular mounting member  776 . The mounting member  776  rests in an opening of the ringed base  754  supported from a lug  778  formed at an edge of the mounting member  776 . A fuse  780  is provided to prevent over-supply of current which may damage an electrical device connected to the plug  750 . The mounting member  776  also has an insulative partition  782  formed on the base  754  to reduce the possibility of any short-circuit between the terminals  770 ,  772 ,  774  from occurring. Protruding from the other side of the mounting member  776  is a contact arm  784  which has a similar structure as the contact arm  441  of the power point connector  400 ′ of  FIG. 11   a / 11   b .  FIG. 20   a  shows a perspective view of the cylindrical holders  904 ′,  906 ′ connected to the terminals  770 ,  772 ,  774  (with the rest of the components of the plug  750  not shown). The contact arm  784  will not be further elaborated here, but how the protruding heads  900 ′,  902 ′ and surface  920 ′ are electrically connected to the respective terminals  770 ,  772 ,  774  will now be described. Each holder  904 ′,  906 ′ stands on a support element  930 ,  932  which is connected via a series of angular elements  934 ,  936  to respective “neutral” and “live” terminals  770 ,  774 . The structure of the angular elements  934 ,  936  is shown in a different perspective in  FIG. 20   b , with the holders  904 ′,  906 ′ omitted. In this embodiment, the angular element  936  is connected to the “live” terminal  774  via the fuse  780  which provides short-circuit protection. The engagement surface  920 ′ is also provided on a support element  938  and is connected to the earth terminal  772  via an angular element  940  (see  FIG. 20   b ). When assembled, the holders  904 ′,  906 ′ are housed in the contact arm  784  with each head  900 ′,  902 ′ and the surface  920 ′ protruding out of the contact arm, similar to that shown in  FIG. 11   c.    
     Coming back to  FIG. 20 , the base  754  has a semi-circular channel  786 ,  788  formed on each side of the terminals  770 ,  772 ,  774  for attaching a flange member  790  similar to that used for the power point connector  400  described earlier. The flange member  790  includes snap fit connectors  792  to clip onto the semi-circular channels  786 ,  788  so that the flange member  790  is movable relative to the base  754 . The flange member  790  has a circular opening  794  to allow the contact arm  784  to protrude through when the mounting member  776  sits on the ringed base  754 . Similar to the connector  400 ′, both ends of the contact arm  784  are covered by inwardly extending protection members  796 ,  798 . This arrangement is conceptually similar to that of the connector  400  of  FIG. 9   a / 9   b  and the contact arm  784  is also rotatable with respect to the protection members  796 ,  798  as shown in  FIGS. 21 and 22 . 
     Using the first embodiment of the track section, as an example, in use, the plug  750  is inserted into the slot  110  (see  FIGS. 1 and 3 ) at a desired point with the contact arm  784  aligned with the protection members  796 ,  798  as shown in  FIG. 21 . As the plug  750  is inserted into the slot  110 , the engagement surface  920 ′ engages the central portion  162  of the earth spring  160  depressing the spring  160  towards the base  120 . The limit being reached when the flat portion  162  of the spring  160  touches the projection  152  of the base  120 . The plug  750  is then rotated 90 degrees so that the contact arm  784  is at right angles to the protection members  796 ,  798  which are prevented from rotating by the projecting edges  176 ,  178 . At the position shown in  FIG. 22 , the contacts  900 ′,  902 ′ presses against the two conductors  126 ,  128  and an electrical connection is formed between the respective wires  762 ,  766  for providing “live” and “neutral” polarities and the two conductors  126 ,  128 . 
     Using the plug  750  as proposed allows a user to connect his electrical device or appliance anywhere along the track section  100  and access electrical power by a simple “insert and twist” action, similar to the power point connector  400 . 
     A power supply/connection unit  500  housed within joints  200 - 260  and then connectors  280 ,  300  is illustrated in  FIGS. 12 and 13 . The unit  500  comprises a housing  506  having a cover  510 . The housing  506  is provided with openings  530  through which run respective cables which connect respective live and neutral contacts of adjacent units  500 , as is described below, and a larger opening  540  for receiving a mains cable to supply power to the unit. Cable catches  520  hold the mains cable and constituent cables in place in the housing  500 . Live and neutral connectors  550  are each provided with three terminals  560  for cable connection and two projecting contacts  570  having a bulbous end  575  which are arranged to engage both sides of the electrical conductors  126 ,  128  of the track section  100 . The housing  500  is provided with projections  580  each having a slot  585  which continues through to the inside of housing  500  so that the contacts  570  may be inserted through the wall of housing  500  with the terminals  560  lying inside the housing  500  and the contacts  570  lying in slots  585  with the bulbous ends  575  projecting from the slots. Earth connector  590  has similar terminals  592  and a three arm earth contact  594 . Of the three arms, the outer two arms have the same undulating form with the middle arm being of straight form the combination being such that earth spring engagement surfaces of the arms slightly overlap to hold the earth spring tightly between them. An opening  596  is provided in housing  500  through which the contacts  595  project. Below the contacts is provided a first lug  598  having an opening  600  which slots around projection  152  of the track section  100 . The contact  594  rests on a surface  602  of the lug  598 . A further lug  604  projects above the lug  598  and engages the cavity  150 . The opposed surfaces of lug  598  and projection  604  have bevelled or slanted surfaces  606 ,  608  to guide the earth spring  160  into engagement with the earth contact  594 . Further lugs  610 ,  612  are provided to engage in cavities  180 ,  182  of the track section to provide further support. 
     A slot  610  is provided on each side of the housing  500  the use of which will now be described with reference to  FIG. 14  which illustrates a housing of the end connector  280 . The housing comprises a base  620  and a cover  624  closed at one end to form a neat end closure. The base  620  includes a mains cable opening  626  and two resiliently displaceable catch members  628 . A tray for receiving the unit  500  is formed by the base  620  and raised perimeter sides  630 ,  632 ,  634 . Two raised lugs  636  are mounted on walls  630 ,  634  and overhand walls  630 ,  634 , projecting into the tray  629 . Mounting openings  640  are provided in the base  200  on either side of the tray  629 . 
     In use, a terminal unit  500  is mounted on a base  620  by placing the unit  500  in the tray  629  and sliding this forward so that slots  610  engage lugs  636  and until the unit  500  passes over displaceable catch member  628  which spring up to lock the unit  500  in place against wall  632 . 
     The unit  500  and base  620  are then engaged with the track section  100  as shown in  FIG. 15  in a sliding fit. In  FIG. 15 , the conductors  126 ,  128  and earth spring  160  base been artificially extrapolated beyond the end of the track section  100  (these components would not normally protrude) and shown in phantoms lines to illustrate the manner of engagement. 
     The housing of a 180 degree joint  260  is shown in more detail in  FIG. 16  and comprises a cover  650  and base  660  which is a similar construction to base  620  of the end connector  280  of  FIG. 14  except that the base  660  has the elements of the base  620  as well as a mirror image so that two terminal units  500  may be connected back to back. A larger central opening  665  for receiving mains cabling is provided so that each terminal  500  can feed the track section to which it is connected separately. Alternatively, the terminal units  500  may be connected one to each other through openings  530  to provide electrical continuity. A 90 degree housing for a 90 degree joint  200  and for a 270 degree joint  220  are shown in  FIGS. 17 and 18 . These are similar to the joint  260  except for the relative angles of the trays for receiving the units  500  and will not be described further. 
       FIGS. 19   a  and  19   b  show respectively front and rear perspective exploded views of a further embodiment of the power supply/connection unit  3000 . The unit  3000  comprises a housing having a top cover  3100  and a base  3200 . The base  3200  has a snap-fit catch  3202 ,  3204  at two ends for engaging a corresponding aperture  3102 ,  3104  formed in the top cover  3100 . Instead of using a connector  550 ,  590  with terminals  560 ,  592  to pierce into the mains cable, a connecting device  3206 ,  3208 ,  3210  is provided which is made of conductive material. The “live” and “neutral” connecting devices  3206 ,  3210  for connecting the respective conductors  2126 ,  2128  (see  FIG. 7   a ) has the same structure as shown in  FIG. 19   a  and only one will be described. 
     The connecting device  3206  has an upper and a lower portion  3212 ,  3214  with opposing grooves in each portion which forms a main channel  3216  as shown in  FIG. 23   a . The main channel  3216  is arranged to receive a conductor  2126  and the upper portion  3212  is then secured to the lower portion  3214  by a screw  3218  which fastens the conductor  2126  in the main channel  3216 . As shown in  FIG. 19   b , the connecting device  3206  further includes two auxiliary channels  3220 ,  3222  formed in the lower portion  3214  with a first channel  3220  arranged to receive a mains wire and in this embodiment the electrical wire carrying “live” or “neutral” polarity of the power supply. The second auxiliary channel  3222  is available for “looping” purpose when, for example, the track section needs to be extended, two of such connection units  3000  can be used and placed in back-to-back relationship with each other so that an electrical wire can connect both of the second auxiliary channels  3222  together. Thus, electrical power can be extended to the newly added track section. 
     To connect an electrical wire to one of the auxiliary channels  3220 ,  3222 , the insulation of the electrical wire is first removed to expose a length of copper which is then electrically attached to one of the auxiliary channels using a screw  3221 ,  3223 . 
       FIG. 19   b  shows the cover  3100  having a “snap-off” section  3106  which can be removed to create an opening to allow electrical wires through when the cover  3100  is fixed onto the base  3200 . 
     The “earth” connecting device  3208  for the earth connection also has two channels  3224 ,  3226  formed in the rear, one for connecting to “earth” of a mains power supply and the second for looping purpose similar to the connecting devices  3206 ,  3210  carrying the “live” and “neutral” polarities. 
     Instead of engaging the earth spring (as described earlier), an alternative is for the earth connecting device  3208  to be coupled to the base  2180  which in the second and third embodiments of the track section  100  is also a conductor. As an example, the earth connecting device  3208  is adapted to electrically connect to the projection  2152  of  FIG. 7   a  which forms part of the base and since the base  2180  is conductive, the earth spring  2160  would also be electrically connected to the earth connecting device  3208  as will now be described. 
     To connect to the projection  2152 , the front of the earth connecting device  3208  comprises resiliently displaceable upper and lower portions  3228 ,  3230 . The lower portion  3230  is further divided into two opposing arms  3230   a ,  3230   b  and together with the upper portion  3228  forms a T-shaped cavity  3232  for engaging the T-shaped projection  2152  with the two opposing arms  3230   a ,  3230   b  engaging both sides of the leg  2152   a  of the projection  2152 . A screw  3234  is then used to close the upper and lower portions  3228 ,  3230  to couple the projection  2152  within the cavity  3232 . 
     Preferably, an inspection cover  3108  covers the three connecting devices  3206 ,  3208 ,  3210  and is preferably made of transparent plastic. The inspection cover  3108  is fixed to the base  3200  using a screw  3110  threaded through a screw holder  3234  formed in the base  3200 . As shown in  FIG. 19   b , the inspection cover similarly comprises a “snap-off” section  3112  to allow wires through similar to that for the top cover  3100 . 
     The terminal connector  3000  also has four guide members  3236 ,  3238 ,  3240 ,  3242  which extends from a surface and is arranged to engage slidably with a track section  100 . The upper guide members  3236 ,  3238  have a cylindrical tapered body and are positioned to slide into respective cavities  2182 ,  2184  (see  FIG. 7   a ) so that each guide member  3236 ,  3238  sits on the surface  2156   a ,  2158   a  of the corresponding projection  2156 ,  2158 . The lower guide members  3240 ,  3242  are generally rectangular and are arranged to be inserted into cavities  2197 ,  2199  formed on the outer surface of the base  2180 . In this way, the terminal connector  3000  is coupled to a track section  100  so that the different polarities of a mains power supply is distributed to the respective conductors and earth spring, or a further extension of the track section can be formed. 
     In other applications, it may not be possible or necessary to have a track section  100 , such as on a support column or a pillar of a building or room. In this case, it may be preferred to have one or more wall electrical sockets to distribute electrical power via the plug  750  or the connector  400 . 
       FIG. 23  shows an exploded view of such a socket  4000  which comprises a front cover  4100  and a back cover  4200 , both preferably made of plastic. The front cover  4100  includes an opening in the form of an elongate slot  4102  through which a contact arm of the plug  750  or connector  400  is inserted. The cover  4100  also includes a switch  4104  which may further include a neon bulb which lights up when power is being supplied through the plug  750  or connector  400 . The switch is of conventional design and will not be elaborated here. Screw holes  4106 ,  4106   a ,  4108 ,  4108   a  are provided, one on either side of the slot  4102  and correspondingly at two ends of the back cover  4200  so that a screw can be inserted through each pair of hole for fastening the socket  4000  to a wall or pillar. The back cover  4200  also includes three fastening holes  4201  which are used to fasten the back cover  4200  to the front cover  4100 . 
     The back cover  4200  includes three cavities  4202 ,  4204 ,  4206  for receiving respective polygonal shaped conductive terminals  4208 ,  4210 ,  4212 . In this particular arrangement, the first terminal  4208  is wired to “neutral”, the second terminal  4210  to “earth” and the third terminal  4212  to “live” of an electrical power source. The electrical wires carrying these polarities, with a length of exposed copper, are inserted through each cavity  4202 ,  4204 ,  4206  as shown in  FIG. 23   a  which depicts a rear sectional view of the wall socket  4000  engaged with a variation of an electrical plug  750 ′ described earlier but comprises a contact arm  784 ′ with hook shaped ends (see also  FIG. 24 ). Each terminal  4208 ,  4210 ,  4212  has a groove  4209  formed on one side of the terminal which allows a screw  4211  to be threaded through to make electrical contact with and to secure the exposed copper to the polygonal terminals  4208 ,  4210 ,  4212 . This is shown more clearly in  FIG. 23   b , which depicts a rear perspective view of the wall socket  4000 . 
     Coming back to  FIG. 23 , an angular element  4214  having an engagement surface  4214   a  extends from the third terminal  4212  to allow engagement by a contact arm of a plug  750  or connector  400 . Nestled between the terminals  4208 ,  4210 ,  4212  lies a conductive member in the form of an earth spring  4216  which functions in a similar way as the earth spring  160  of  FIGS. 5 and 6 . The earth spring  4216  is typically made of flexible conductive material and is supported by four flexible arcuate legs  4218 ,  4220 ,  4222 ,  4224  (leg  4224  hidden from view) similar to the wings of the earth spring  160  of  FIGS. 5 and 6 . Each of these legs  4218 ,  4220 ,  4222 ,  4224  rests in respective holders  4226 ,  4228 ,  4230 ,  4232  formed on the back cover  4200 . 
     Typically, the wall socket  4000  comes assembled ready for use. This means that the terminals  4208 ,  4210 ,  4212  are positioned in respective cavities and the back cover  4200  is fastened to the front cover  4100  using screws though holes  4201 . 
     In use, the electrical mains wires are stripped to expose a length of copper which are inserted accordingly from the bottom and into each respective cavity  4202 ,  4204 ,  4206 . Screws  4211  are then inserted through the grooves  4209  to make electrical contact with the exposed wires. The wall socket  4000  is then positioned as desired on a wall column or pillar and mounted using screws through holes  4106 ,  4106   a  and  4108 ,  4108   a . The socket  4000  is now ready to receive a connector  400  or plug  750 . 
       FIG. 24  shows a perspective view of the plug  750 ′ being engaged with two terminals  4208 ,  4212  of the socket  4000 . As mentioned earlier, the plug  750 ′ is a variation of that depicted in FIG.  21 / 22  and which comprises a contact arm  784 ′ with hooked ends instead of resiliently displaceable contacts at each end. The contact arm  784 ′ of this variation is similar to the first variation of power point connector  400  described earlier in  FIG. 9   a / 9   b . The contact arm  784 ′ of the plug  750 ′ is inserted through the slot  4102  ( FIG. 23 ) and resiliently biases the earth spring  4216  towards the back cover  4200  which allows the contact arm  784 ′ to be rotated through 90 degrees (by rotating the plug  750 ′) so that respective hooked ends of the contact arm  784 ′ are in an interference fit with the engagement surface  4214   a  of the angular element connected to the “live” terminal  4212  and a surface of the polygonal “neutral” terminal  4210 . In this manner, power is being distributed through the socket  4000 , through the plug  750 ′ and then transmitted to an electrical device connected to the plug  750 ′. 
     As mentioned, the cable runs  146 ,  148  of track section  100  are adapted for data and/or communication cables. Such cables are fed through the cable runs  146 ,  148  and also through portions of the connector/joint housings on each side of the trays which receive the units  500 . The cables may enter and exit the track through opening(s)  665 . In order to allow user access to the data/communication cables, a 180 degree joint base as shown in  FIG. 16  is used but with a different cover  700  as shown in  FIG. 19 , which is provided with openings  710 ,  720  for network connector or telecommunications cable sockets. 
     In an alternative, the cable runs  146 ,  148  of track section  100  are in the form of further conduits  2147 ,  2149  adapted to hold further conductors which can be used to carry and distribute communication signals and the base  2180  and cavities  2182 ,  2184  similarly forms an EMI shield to shield these data conductors from the electrical conductors. This variation forms a fourth embodiment of the apparatus of the invention and is shown in  FIG. 25  which will be described with referenced to the track section of  FIG. 7   a . However, it should be apparent that the track sections proposed by the first and second embodiments can similarly be modified to accommodate further conductors as will be described below. 
       FIG. 25  illustrates a cross-sectional view of the track section  100  of the third embodiment adapted to receive further conductors in two separate cavities  2300 ,  2302  formed in the conduits  2147 ,  2149 . Since these two cavities  2300 ,  2303  are mirror images of each other, only one will be described. 
     The cavity  2300  is formed by projecting elements  2304 ,  2306  which includes hook formations  2308 ,  2310  for clipping to corresponding formations  2312 ,  2314  of the cover  2130 . The cover  2130  has an opening in the form of an elongate slot  2131  which is similar to the slot  110  of the first embodiment and allows one or more data and/or communications connector (to be described below) to be connected at any point along the slot  2131  to transmit communication signals between the track section and the equipment connected to the other end of the connector. The slot  2131  is shown in  FIG. 26  which depicts a perspective view of the track section  100  of the fourth embodiment. 
     The cover  2130  includes deformable flaps  2316 ,  2318  of a similar material as the flap  154  of the first embodiment, the flaps being used to cover the slot  2131  (and also the cavity  2300 ). In the cavity  2300  sits an elongate insulative tray  2320 , preferably made of PVC, used to carry four identical conductors  2322  in spaced grooves  2324  which extends parallel to the conductors  2126 ,  2128  carrying electrical power. The tray  2320  serves to insulate the four conductors  2322  from the base  2180  since the conductors  2322  are used to carry communication signals, for example voice or data signals. The cavity  2300  is shaped to receive a data and/or communications connector which provides an interface for signals between a telecommunication or data device and the conductors  2322 . 
       FIGS. 27 to 29  show different views of a data and/or communications connector in the form of an adapter suitable for use with the track section of  FIG. 25 . A perspective front view of the adapter  800  is shown in  FIG. 27  comprising a housing  802  having a central aperture  804  of conventional design to receive a corresponding plug (not shown), such as a telephone plug. In the aperture  804  are four identical conductors  806  slanted at a predetermined angle with ends of the conductors  806  between two adjacent inner walls of the aperture  804  to match corresponding contacts of a telephone plug. 
     At the other end of the adapter  800  extends a connecting portion  808 , as shown more clearly in  FIG. 28  arranged to be inserted into the cavity  2300  by pushing through the flaps  2316 ,  2318  of the cover  2130 . The connecting portion  808  has an outward facing surface which projects four equidistantly spaced conductive contacts  810 . Each of these contacts  810  are electrically connected to respective ones of the slanted conductors  806  disposed in the aperture  804 . The connecting portion  808  also has two catches  812 ,  814  on opposing side surfaces for engaging the projecting elements  2304 ,  2306  of the track section  100  at edges  2326  and  2328  (see  FIG. 25 ). Each catch  812 ,  814  is tapered towards the insertion direction to facilitate ease of entry pass the edges  2326 ,  2328 . Each of the catches  812 ,  814  are also linked to respective catch release buttons  816 ,  818  disposed at the housing  802  as shown in  FIG. 29 . The buttons  816 ,  818  are disposed in opposite directions and sit on springs  820 ,  822 ,  824 ,  826  which bias the buttons  816 ,  818  in an outwardly protruding manner. 
     In use, the connecting portion  808  of the adapter  800  is pushed through flaps  2316 ,  2318  at any point along the slot  2131  and into the cavity  2300 . The edges  2326 ,  2328  of the projecting elements  2304 ,  2306  of the track section  100  act on the tapered surfaces of the catches  812 ,  814  facilitating the movement inwards and subsequently locking the connecting portion  808  in place when the catches  812 ,  814  are free to be biased outwards, as shown in  FIG. 30 . In this position, the contacts  810  are received in the grooves  2324  and electrically connected to the conductors  2322 . Preferably, each contact  810  is resiliently biased and the protrusion distance is such that when contact is made with each conductor  2322 , the resiliently biased contact  810  engages the conductor  2322  to give a pressing electrical contact. If a communications equipment, for example a telephone, is connected at the other end of the adapter  800 , the equipment would be able to receive voice or data signals in a conventional way with the added flexibility of being connected at any point along the slot  2131 . To withdraw the adapter  800  from the cavity  2300 , both buttons  816 ,  818  are depressed against the springs  820 ,  822 ,  824 ,  826  which retract the corresponding catches  812 ,  814  within the connecting portion  808  so that the catches  812 ,  814  are free from the edges  2326 ,  2328 . In this way, the connecting portion  808  can be withdrawn from the cavity  2300 . 
     It should be apparent that the number of conductors  2322  that is carried by the tray  2320  which typically corresponds to the number of contacts  810  varies depending on application. For example, for data communications applications such as Ethernet, eight wires are necessary to carry control and data signals and thus the adapter  800  will have eight slanted connectors  806  as shown in  FIG. 31 . Accordingly, the connecting portion  808  will have eight spaced contacts  810  and similarly, the tray  2320  will carry eight conductors  2322  to adhere to the communications protocol. 
     In a further variation, cavities  2300 ,  2302  may receive a different number of conductors  2322 . For example, the first cavity  2300  may be used to support voice communications and four conductors  2322  are provided therein. On the other hand, the second cavity  2303  may provide eight conductors  2322  to meet the Ethernet protocol as described above. The track section  100  may also be adapted to provide one or more elongate slots  2131  just to support data or communication signals without the main slot  2154  for distributing electrical power. 
       FIG. 32  shows a perspective view of the track section  100  of  FIG. 30  with an adapter  800  inserted at a point along the slot  2131  to engage the elongate data conductors  2322  and a data and/or communications terminal connector being arranged to slidably engage an end of the data conductors  2322 . The terminal connector  850  thus acts as an interface which links the conductors  2322  to a data communications cable  852  carrying a number of electrical wires providing communication signals. 
       FIG. 33  shows an exploded perspective view of the terminal connector  850  which comprises a tray member  852  having four spaced U-shaped terminals  854  extending from one end. At the other end of the tray member  852  are four spaced wire contacts  856  which are electrically connected to the respective U-shaped terminals  854  and which extends upwards from the tray member  852 . Each wire contact  856  has two arms  856   a ,  856   b  which co-act to hold an electrical wire therebetween. Situated between the terminals  854  and the contacts  856  is a rectangular formation  853  for engagement by a screw  880  to hold the tray member  852  in place which will be described in more detail later. 
     Part of the tray member  852  is received inside a corresponding housing  858  with a base  860  to support the tray member  852  and two opposing side supports  862 ,  864  connected to the base  860 . Each side support  862 ,  864  has a rectangular aperture  862   a ,  864   a  formed therein for locking with two catches  866 ,  868  (the catch represented by reference numeral  868  is not shown) located on the sides of the tray member  852 . The base  860  extends only part of the housing  858  such that when the tray member  852  is received inside the housing  858 , the four terminals  854  protrude out of the housing  858  as shown in  FIG. 34 , which depicts a side perspective view of an assembled interface connector  850 . The four wire contacts  856  would thus be exposed outside of the housing  858  which facilitates connecting the wire contacts  856  to the wires carried by the communication cable  852 . 
     The terminal connector  850  further comprises an auxiliary cover  870  for covering the four wire contacts  856 . As shown in  FIGS. 33 and 34 , the auxiliary cover  870  has a rectangular opening  870   a  through which the communication cable  852  is inserted (see  FIG. 32 ) so that the electrical wires within can be connected to the wire contacts  856 . The auxiliary cover  870  has two side lug holes  872  which are used for coupling the cover  870  to the corresponding lugs  874  located on the housing  858 . 
     After the electrical wires of the communication cable  852  are properly connected to the wire contacts  856  and the cover  870  secured to the housing  858 , the interface connector  850  is then inserted into one of the two cavities  2300 ,  2302  (see  FIG. 32 ) carrying the data conductors  2322  so that each U-shaped terminal&#39;s apex engages respective ones of the data conductors  2322 . In this way, when an adapter  800  is inserted anywhere along the slot  2131 , communication signals carried by the communication cable  852  is transmitted to the adapter  800  via the U-shaped terminals  854  and the conductors  2322 . 
     Preferably, to hold the terminal connector  850  in place in the cavity  2130 , a coupling element  876  is used to couple the interface connector  850  to the edges  2326 ,  2328  of the track section  100 . The coupling element  876  has a centre countersink hole  878  through which the head of the countersunk screw  880  sits. To engage the edges  2326 ,  2328  of the cavity  2300 , the sides of the coupling element  876  are tapered at an angle to match the slope of the edges  2326 ,  2328  so that when the interface connector  850  is inserted into the cavity  2300 , the two tapered sides of the coupling element  876  sit on respective edges  2326 ,  2328  and the countersunk screw  876  engages the formation  853  via a hole  882  on the top side of the housing  858 . In this way, when the screw  880  is tightened, pressure is asserted on the coupling element  876  and onto the edges  2326 ,  2328  to hold the interface connector  850  in place. 
       FIG. 32  shows the connector  850  being secured to the track section  100  using the coupling element  876  and the screw  880 . In this way, communication signals are distributed via the connector  850 , the data conductors  2324  and finally to the data connector  800  and vice versa. 
     Preferably, the connector  850  is also housed in the housing  3000  of the connector of  FIG. 19   a / 19   b . In this case, the top cover  3100  of the housing  3000  has two further openings  3114 ,  3116 , one on each side of the snap-off section  3106 . Each opening  3114 ,  3116  is positioned to allow the communication cable  852  to pass through. 
     The described embodiments of the track section may be particularly used as a fixed power distribution apparatus, with the combination of track sections and connectors as shown in  FIG. 1  being connected to a suitable supporting surface, such as a wall or movable partition or furniture item. However, the described embodiments may also be used in a movable manner, for example as an extension cable, with a single track section being provided with two end connectors, one end connector being connected to a cable having a suitable plug at its free end, in the manner of a normal extension cable. One or more power point connectors may then be attached to the track section according to need.