Patent Publication Number: US-RE44490-E

Title: Electrical clamp connector and connecting terminal

Description:
BACKGROUND OF THE INVENTION 
     The invention relates to an electrical clamp connector and connecting terminal that, per pole, has at least two spring clamp connectors, which are opposite-lying and mirror-symmetric with respect to a central plane, for connecting electrical conductors, in which the electrical conductors can be plugged in from the same connection direction and by means of which the electrical conductors can be connected electrically to a common busbar in the interior of the terminal, the busbar having an additional connecting contact, which is arranged in the central plane between the two conductor clamp connections on the side of the terminal facing away from the conductor clamp connections and serves for connecting a countercontact external to the terminal. 
     Electrical clamp connectors and connecting terminals of this type are known (see DE 94 20 097 U1). They are produced with one pole or multiple poles; for example, in a multi-pole embodiment, several one-pole individual terminals, each of which has its own insulator housing, are arranged in series and are locked together mechanically (see FIG. 4 in DE 94 20 097 U1) or, for example, in a multi-pole embodiment, several one-pole individual terminals are arranged, in a known way, in the side-by-side receptacle chambers of a common insulator housing. 
     The aforementioned type of clamp connector and connecting terminal has the advantage that the electrical conductors are oriented in the same direction; that is, they can be plugged in from the same connection direction into the conductor clamp connections of the terminal and, for each pole, the terminal can produce an electrical connection to an external countercontact by means of an additionally present connecting contact on the other side of the terminal. Such a countercontact, for example, may be a terminal pin, which is soldered in a printed circuit board and can be plugged onto the terminal. 
     However, a drawback is that the known terminals of this type require a lot of space. In particular, the design width measured in the traverse direction to the central plane of the terminal is very large, because, for terminals of this type, the additional connecting contact for an external countercontact is arranged in the central plane between the opposite-lying conductor clamp connections. 
     Starting from this prior art, the problem of the invention consisted in creating a terminal of this type that makes possible a very small design construction. 
     SUMMARY OF THE INVENTION 
     The solution in accordance with the invention is characterized in that the especially small-construction design features of a terminal that is produced from a single piece of spring steel sheet and a busbar rod and is already known (see DE 196 54 523 C2) are combined with the new features that the busbar rod has at least one cross projection for forming the additional connecting contact, this cross projection being arranged in the region of the free opening of the spring steel sheet and extending through the free opening in the spring steel sheet such that the busbar rod is positioned on one side of the spring steel sheet and the cross projections for forming the additional connecting contact are positioned on the other side of the spring steel sheet. 
     In order to form the additional connecting contact, the busbar rod may have one or two cross projections. It is provided that two cross projections are present, which together form a socket contact. Alternatively, only one cross projection may be provided, which forms a plug-in contact. 
     An especially cost-effective embodiment of the invention provides, that the busbar rod (as viewed in cross section) has a V-shaped or U-shaped cross-sectional form and, with its margin edges running in the lengthwise direction of the rod, lies against the spring steel sheet and that the cross projection or cross projections of the busbar rod, starting from the margin edges of the busbar rod, project through the free opening of the spring steel sheet. 
     The cross projections may be produced in one piece with the busbar rod in terms of manufacturing technology. However, it is also possible for the cross projections (e.g., in the form of a socket contact) to be produced separately and joined to the busbar as a finished assembly. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
       Further embodiment examples of the new clamp connector and connecting terminal will be described in greater detail on the basis of the drawings. 
       Shown are: 
         FIGS. 1-3  a first embodiment example of a terminal in accordance with the invention, 
         FIGS. 4-6  a second embodiment example of a terminal in accordance with the invention. 
     
    
    
     DETAILED DESCRIPTION 
       FIGS. 2 and 3  show a one-pole clamp connector and connecting terminal, consisting of one piece of spring steel sheet  10  and a busbar rod  11 . 
     From the piece of spring steel sheet  10 , a pair of leaf springs  13 ,  14  are cut out mirror-symmetrically to the central plane  12  (see  FIG. 3 ) and, together with the busbar rod  11 , each forms a terminal site for connecting the electrical conductors  15  and  16 . The electrical conductors may have different conductor cross sections, because the cut-out leaf spring tongues  13  and  14  work independently of each other and are joined together only via the two outer crosspieces  17  and  18  (see  FIG. 3 ) of the spring steel sheet. The crosspieces  17  and  18 , in turn, are locked together with the busbar rod  11  in fixed position. 
     The busbar rod  11  is constructed with a V shape in cross section and has a spine  20  (in the embodiment example depicted, this is the V-shaped bent part of the busbar rod) and two cross projections  21  and  22  projecting away from it. 
     The cross projections  21  and  22  can make a slight spring movement relative to each other and together form a socket contact  23 . 
     It is essential that the cross projections of the busbar rod project through the free opening  19  of the spring steel sheet  10  in such a way that the spine  20  of the busbar rod  11  is positioned on the left side of the spring steel sheet  10  as depicted in the drawing (with the consequence that the spine  20  is available for forming the conductor clamp connections for the electrical conductors  15  and  16 ), and that the cross projections  21  and  22  are positioned on the right side of the spring steel sheet  10  as depicted in the drawing and, in this embodiment example, form the socket contact  23 . 
     The socket contact  23  can serve for receiving all connector pins, terminal pins, or other contact pins known in the prior art, including such solid (plug-in) electrical conductors  24  that (as depicted) can be inserted into the socket contact in the way of a connector pin. 
       FIG. 1  shows the terminal according to  FIGS. 2 and 3  installed in the insulator housing of the left half  25  of the depicted  3 -pole plug-in connector. 
     Provided for each pole in the insulator housing of the left plug-in connector half  25  is its own receptacle chamber, protected by insulation on all sides, in which the terminal is inserted via a respective opening present in the left side of the plug-in connector half  25 , after which the front-side opening is closed by means of a cover (not depicted), which, at the same time, has the conductor insertion openings and the conductor guide channels for the electrical conductors  15  and  16  that are to be connected for each pole. 
     The other half  26  of the plug-in connector depicted in  FIG. 1  is, in a known way, a plug-in connector part, which, has a respective connector pin  27  for each pole. In  FIG. 1 , the connector pin is formed by the stripped ends of solid electrical conductors, which are held in the insulator housing in fixed position. 
     The plug-in connector half  26  depicted may also be once again pulled out of the plug-in connector half  25  if necessary, this being of advantage, for example, for the installer of lighting systems, because he can remove a single lamp that has become defective from the lighting system by simple opening of the plug-in connector, without it being necessary to loosen the electrical conductors  15  and  16  wired to the single lamp, from the plug-in connector half  25 . 
       FIG. 4  shows a second embodiment example of the clamp connector and connecting terminal in accordance with the invention, in which the busbar rod  28  has only one cross projection, which is constructed in the form of a plug-in contact  29 . For fixing the plug-in contact in fixed position in the free opening  30 , a lug projection  31  is present on the outer crosspiece  32  of the piece of spring steel sheet  33 . 
       FIG. 5  shows the plug-in contact  29 , which is plugged into the socket contact  34 , external to the terminal, for producing an electrical connection. The design of this socket contact is known. It is also possible to use other construction designs in place of the socket contact  34  depicted in  FIG. 5 . 
       FIG. 6  shows a plug-in connector, the two plug-in connector halves of which,  35  and  36 , are constructed in accordance with the teachings of the invention (compare to this  FIG. 2  and  FIG. 4 ).