Abstract:
A bent-back plug-type connector for coaxial cables includes a bent-back outer conductor having a first conductor section which extends along a plug axis and a second conductor section which adjoins the first conductor section and is arranged at an angle with respect thereto, as well as a first inner conductor, which is arranged concentrically and insulated in the first conductor section, and a second inner conductor, which is arranged concentrically and insulated in the second conductor section and is detachably connected to the first inner conductor in the corner region of the bent-back outer conductor. With such a plug-type connector, simpler fitting, a secure and permanent connection and simpler and more cost-effective production are achieved by virtue of the fact that the first inner conductor has a square cross section, and the fact that an opening is provided in the first inner conductor.

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to the field of plug-type connector technology for coaxial cables. Said invention relates to a bent-back plug-type connector for coaxial cables as per the preamble of claim  1 . 
       PRIOR ART 
       [0002]    In the automotive industry, RF systems (GPS, external aerial for mobile radio, car radio etc.) are being increasingly integrated in the vehicles, and coaxial cables have to be laid and connected in the vehicle for these RF systems. Standards have been introduced in the USA and in Europe for such coaxial automotive plug-type connectors in order to make systems from different manufacturers compatible with one another. The existing standard in the USA is SAE/USCAR-18, and this corresponds to DIN standard 72594-1 (FAKRA) in Europe. The international standard is ISO-20860-1. 
         [0003]    In this connection, the applicant already provides automobile plug-type connectors which are covered under the term ARC (Automotive Radiofrequency Connectors) and which have been developed as RF plug-type connector families specifically for telematics, multimedia, safety and security applications in automobiles and heavy goods vehicles. 
         [0004]    This family includes angled plug-type connectors in which the coaxial cable to be connected is generally inserted into the plug-type connector such that it is bent-back through 90° with respect to the plugging direction or plug axis. 
         [0005]    To date, the inner conductor in such bent-back plug-type connectors has been composed of two straight inner conductors which were plugged one into the other in a manner oriented perpendicular to one another during assembly of the plug-type connector. To this end, the first inner conductor which was oriented in the plugging direction and was formed as a solid rotary part was provided at the end with a fork into which a pin contact which is connected to the inner conductor of the coaxial cable was inserted perpendicular to the fork. Such angled plug-type connectors for the automotive sector are disclosed, for example, in DE-A1-10 2004 041 809 or DE-B3-103 39 965. 
         [0006]    One disadvantage of the known designs is that the first inner conductor is not secured against twisting about its longitudinal axis or the plug axis. This can lead to a twisted first inner conductor first having to be straightened with a great deal of effort, so that the second conductor can be inserted into the fork. Furthermore, the fork is open at the rear, so that the second inner conductor can slip out of the fork at the rear given unfavorable circumstances. Finally, the pin contact of the second inner conductor in the fork is only jammed into the fork but not latched in. 
       DESCRIPTION OF THE INVENTION 
       [0007]    The object of the invention is to improve a bent-back plug-type connector of the type described in the introduction such that the disadvantages of known solutions are avoided and that, in particular, a plug-type connector is produced which has a reliable and long-lasting connection that is easy to assemble, particularly in the region of the inner conductor, and which can be produced in a simple and cost-effective manner. 
         [0008]    The object is achieved by all the features of claim  1 . The essence of the invention is the use of a first inner conductor which has a square cross section, and the provision in the first inner conductor of an opening which is bounded on both sides in the plug axis and into which the second inner conductor can be inserted in a latching and contact-making manner by way of one end. On account of the square cross section, it is possible to prevent the first inner conductor from twisting in the plug axis without further outlay, so that the opening is always correctly oriented for insertion of the second inner conductor. Bounding the opening on both sides ensures that the second inner conductor cannot slip out of the opening at the sides. Insertion in a latching manner provides additional security. 
         [0009]    According to a preferred refinement of the invention, the first inner conductor is produced as a stamped and bent part from an elongate strip of a metal sheet and forms a tube which is concentric with respect to the plug axis, with, in particular, the first inner conductor having a cross section in the form of an equilateral triangle with three side walls, two of the side walls abutting in one corner of the triangle so as to form a butt joint, and the opening for inserting the second inner conductor at the rear end of the first inner conductor is in the form of a butt joint of extended width between the two side walls. The two side walls which abut at an angle of 60° and so as to form a butt joint form a slot-like opening in the region of the expanded butt joint, it being possible for the walls of said opening to be pressed elastically outward when a pin with a relatively large diameter is inserted, and to spring back again when the pin is withdrawn. According to one development, if, in particular, the second inner conductor is formed in the manner of a jack plug at that end by way of which it is inserted into the opening, the elastic behavior of the side walls creates a latching-in effect after the thickened pin is inserted. Production of the first inner conductor as a stamped and bent part has proven particularly cost-effective and simple. 
         [0010]    Another refinement is characterized in that the first inner conductor has a cross section in the form of an equilateral triangle with three side walls, in that two of the side walls abut in one corner of the triangle so as to form a butt joint, and in that the opening for inserting the second inner conductor is arranged at the rear end of the first inner conductor between two fork arms of a contact fork which is formed there. 
         [0011]    In the stamped and bent part, security against slipping out is provided by the opening being in the form of a slot and being bounded toward the rear end of the inner conductor by an integrally formed lug. This lug can be bent obliquely inward in order to facilitate insertion of the second inner conductor. 
         [0012]    The first inner conductor can be prevented from twisting in a simple manner by the first inner conductor being held in a concentric manner in the first conductor section of the outer conductor by means of a substantially cylindrical dielectric, by the dielectric having a central through-opening for accommodating the first inner conductor, and by the cross section of the central through-opening corresponding to the square cross section of the first inner conductor. 
         [0013]    That end of the second inner conductor which is averted from the first inner conductor is designed to accommodate the inner conductor of the coaxial cable to be connected. 
         [0014]    The dielectric has an opening, in particular a slot, through which the second inner conductor can be inserted into the internal first inner conductor from the side, in the region of the opening in the first inner conductor. 
         [0015]    The outer conductor is preferably bent back through an angle of approximately 90°. 
         [0016]    On account of the design as a stamped and bent part, it is particularly easy to create a situation where, at the front end of the first inner conductor, the side walls in each case turn into individual contact tongues which together form a bushing for accommodating a plug pin which is provided on a mating piece for the plug-type connector, which bushing can be widened such that it can spring back. 
         [0017]    The two conductor sections of the outer conductor are preferably hollow-cylindrical, and the outer conductor is integrally produced from a metal sheet as a stamped and bent part. As a result, production can be simplified further and be more cost-effective. 
         [0018]    Contact tongues for making contact with a mating piece of the plug-type connector are then arranged in the first conductor section of the outer conductor. Latching tongues for latching into an insertable transition piece for the outer conductor of the coaxial cable are arranged in the second conductor section of the outer conductor. 
         [0019]    The first conductor section of the outer conductor is preferably in the form of a hollow cylinder which is closed over the circumference, a plastic housing is snapped onto the first conductor section of the outer conductor, and latching tongues for latching into the plastic housing are provided on the first conductor section, latching points are formed on the first conductor section in order to connect the plastic housing and the outer conductor in a rotationally fixed manner, the plastic housing and the latching points are formed and arranged such that the plastic housing can be latched in graduated rotation positions, in particular in steps of 45°. On account of the closed design of the outer conductor in its front, first conductor section, the outer conductor can be used there as a guide for the plastic housing and wobbling play between the outer conductor and the plastic housing can thus be prevented in a simple and reliable manner. 
         [0020]    In particular, the plug-type connector comprising the plastic housing, the outer conductor and the first inner conductor is compatible with the interface standards SAE/USCAR-18 and FAKRA (DIN 72594-1). 
     
    
     
       BRIEF EXPLANATION OF THE FIGURES 
         [0021]    The invention will be explained in greater detail below with reference to exemplary embodiments in conjunction with the drawing, in which 
           [0022]      FIGS. 1-4  show a preferred exemplary embodiment of a bent-back plug-type connector according to the invention in the assembled state in various views, with  FIGS. 1 and 3  showing the plug-type connector with a sectioned outer conductor,  FIG. 2  showing a perspective side view of the plug-type connector, and  FIG. 4  showing the plug-type connector in a view from the front, as seen in the direction of the plug axis; 
           [0023]      FIGS. 5-8  show analogous views of the plug-type connector as per  FIGS. 1-4  in the as yet unassembled state; 
           [0024]      FIG. 9  shows various partial figures of various views of the first inner conductor from the exemplary embodiment of  FIGS. 1-4 ; 
           [0025]      FIG. 10  shows various partial figures of various views of the outer conductor from the exemplary embodiment as per  FIGS. 1-4 ; 
           [0026]      FIG. 11  shows an enlarged illustration of a detail from  FIG. 5  with a second inner conductor inserted, 
           [0027]      FIG. 12  shows two partial figures of various views of the dielectric from the exemplary embodiment as per  FIGS. 1-4 ; 
           [0028]      FIG. 13  shows various partial figures of various views of the first inner conductor according to another exemplary embodiment with a contact fork for accommodating the second inner conductor; and 
           [0029]      FIG. 14  shows two partial figures of the longitudinal section through and a perspective side view of the second inner conductor from  FIG. 2 . 
       
    
    
     WAYS OF IMPLEMENTING THE INVENTION 
       [0030]      FIGS. 1-14  show various views and assembly states of exemplary embodiments of the plug-type connector according to the invention and its components. The bent-back plug-type connector  10  comprises a bent-back outer conductor  12  (see  FIG. 10 ), two inner conductors  14  and  15  which are arranged in a concentric manner inside the outer conductor (also see  FIG. 14 ), a standardized plastic housing  11 , a transition piece  17  and a press sleeve  20 . The first inner conductor  14  is mounted in an insulated manner in the front conductor section  12   a  of the outer conductor  12  by means of a cylindrical dielectric  13  (see  FIG. 12 ). The hollow-cylindrical, electrically conductive transition piece  17  forms a plug connection with the end in the rear conductor section  12   b  of the outer conductor and is there latched by means of latching tongues  23  which latch into corresponding recesses on the outer face of the transition piece  17  ( FIG. 11 ). The outer conductor  19  of the coaxial cable  21  (for example a braided shield) which is to be connected is pushed over the other end of the transition piece  17  and pressed by means of the surrounding press sleeve  20 . 
         [0031]    The outer conductor  12  which is illustrated in detail in  FIG. 10  is in the form of an integral stamped and bent part and has corresponding butt joints  32 . The outer conductor  12  comprises two tubular conductor sections  12   a  and  12   b  which adjoin one another and are at a right angle to one another. Two latching tongues  22  are formed opposite one another at the top and bottom on the first conductor section  12   a , it being possible for the plastic housing  11  to be latched to the conductor section  12   a , after being pushed onto it, by means of said latching tongues (see, for example,  FIG. 3 ). Two contact tongues  33  which ensure electrical contact between the outer conductor  12  and the corresponding outer conductor of the mating piece when the plug-type connector  10  is inserted into a mating piece are arranged on the side of the first conductor section  12   a . Furthermore, latching points  31  which serve to orient and guide the plastic housing  11  which is pushed onto the outer conductor  12  are formed on the sides behind the contact tongues  33  by embossing. The design of the outer conductor  12  as a hollow cylinder which is closed over the circumference ensures that the plastic housing  11  is guided on the outer conductor and undesirable wobbling play between the outer conductor  12  and the plastic housing  11  is reliably avoided. The plastic housing  11  is preferably formed such that it can be positioned in various rotation positions, which are each rotated through 45°, relative to the outer conductor in interaction with the latching points  31 , Other latching steps of 30°, 60° or 90° are likewise possible. 
         [0032]    The first inner conductor  14  according to  FIG. 9  is designed as an integral stamped and bent part. Its cross section is an equilateral triangle ( FIGS. 9   a  and  d ) and has the side walls  24   a ,  24   b  and  24   c  which at the front end in each case become individual contact tongues  25   a ,  25   b  and  25   c  which can be elastically bent in the radial direction. The arrangement of the contact tongues  25   a ,  25   b  and  25   c  in a triangle forms a bushing into which a plug pin  10  which is present on the mating piece of the plug-type connector can be inserted in a contact-making manner. A slot-like opening  27 , into which the second inner conductor  15  can be inserted in a latching manner by way of its front part which is formed in the manner of a jack plug (see  FIGS. 11 ,  14 ), is formed between the top abutting side walls  24   b  and  24   c  at the rear end of the first inner conductor  14 . The opening  27  is formed by the side walls  24   b  and  24   c  being provided with a recess  26  at the upper edge. A further recess  30  in the third side wall  24   a  ensures that the opening  27  is accessible from below. A lug  28 , which is bent obliquely inward and blocks the opening  27  toward the end, is formed at the rear end of the recess  30 . This ensures that the second inner conductor  15  which is inserted in the opening  27  cannot slip out of the opening  27  at the rear. At the same time, the inclined position of the lug  28  facilitates insertion of the second inner conductor  15  into the opening  27  from below. 
         [0033]    The second inner conductor  14  is shown in detail in  FIG. 14 . Along its longitudinal axis, said second inner conductor comprises a sleeve part  46  with an axial bore  48  for accommodating the inner conductor of the coaxial cable and adjoining this a plug part  47  in the form of a jack plug which, at the front end, has a conically tapering tip  49  and a circumferential latching groove  50  formed behind it. 
         [0034]    The first inner conductor  14  is held in a rotationally fixed manner in a central through-bore  38  in the dielectric  13  ( FIG. 12 ), said through-bore having a corresponding triangular cross section. The dielectric  13  is divided into a first cylindrical section  36  with a relatively small outside diameter and a second cylindrical section  37  with a relatively large diameter. In this case, the outside diameter of the second section  37  is selected such that it matches the inside diameter of the first conductor section  12   a  of the outer conductor  12 . The first section  36  accommodates the contact tongues  25   a ,  25   b  and  25   c  of the first inner conductor  14  and conforms to the plug-type connector standard. In the region of the opening  27  in the first inner conductor  14 , the central through-opening  38  in the dielectric  13  is open toward the bottom by means of a slot  39 , so that the second inner conductor  15  can be inserted into the opening  27  in the first inner conductor  14  through the slot  39  transverse to the plug axis  34 . Bevels  40  on the walls of the slot  39  also facilitate insertion of the second inner conductor  15 . The through-opening  38  in the dielectric  13  is designed to be larger in terms of cross-sectional area than the first inner conductor  14 . A projection  29  which serves to guide and fix the first inner conductor  14  in the through-opening  38  is formed on the free upper edge of the side wall  24   b  of the first inner conductor  14 . 
         [0035]    For assembly of the plug-type connector  10 , the first inner conductor  14 , together with the dielectric  13 , is first inserted in a clamping manner into the first conductor section  12   a  of the outer conductor  12  (clamping tongues  41 ). Furthermore, the transition piece  17  is pushed into the second conductor section  12   b  in a latching manner. The coaxial cable  21  is prepared as per  FIG. 5  and the second inner conductor  15 , together with its sleeve-like section, is pushed over the exposed end of the inner conductor  16  of the coaxial cable  21  and fixed. The cable end with the second inner conductor  15  is then inserted into the second conductor section  12   b  through the transition piece  17 , until the front end of the second inner conductor  15  latches in the opening  27  in the first inner conductor  14 . At the same time, the outer conductor  19  of the coaxial cable  21  moves over the lower end of the transition piece  17  and can be fixed there in a contact-making manner by means of the press sleeve  20  pushed over it. 
         [0036]    An embodiment of the first inner conductor, which embodiment represents an alternative to  FIG. 9 , is illustrated in  FIG. 13 . In the case of this first inner conductor  14 ′, the apparatus for connection to the second inner conductor  15  is in the form of a contact fork  42  between whose two fork arms  43  and  44  the opening  45  for accommodating the plug part  47  of the second inner conductor  15  is arranged. Reliable and mechanically stable contact between the two inner conductors  14 ′ and  15  is likewise achieved on account of this refinement of the first inner conductor  14 ′. 
         [0037]    Overall, the plug-type connector according to the invention has the following properties and advantages:
       the plastic housing  11  can be supported over the entire length of the outer conductor on account of the closed shape of the outer conductor  12  at the front, this resulting in a significant reduction in wobbling play (the outer conductor was previously slotted and pressed slightly inward at its front end, so that contact was made with the mating piece here);   contact with the outer conductor of the mating plug is ensured by the two slightly pressed-in lugs;   the outer conductor  12  can snap into the plastic housing  11  by way of the latching tongues (snap-action lugs)  22  at the front;   free rotation of the plastic housing  11  about the plug axis  34  is also possible on account of improved guidance between the plastic housing  11  and the outer conductor;   the lateral latching points  31  on the outer conductor  12  permit stepped, for example 45°, shifting of the rotation position of the plastic housing  11  around the plug axis  34 ;   the snap-action of the second inner conductor  15  which is configured in a mushroom-like manner and in the form of a jack plug, in the first inner conductor  14 ,  14 ′ is more reliably ensured;   in contrast to the round milled/twisted first inner conductor, the triangular first inner conductor  14 ,  14 ′ is already secured against twisting in the dielectric  13  or no longer has to be straightened before insertion of the second inner conductor  15 ; and   the snapped-in second inner conductor  15  is guided; it can no longer slip out at the rear.       
 
       LIST OF REFERENCE SYMBOLS 
       [0000]    
       
           10  Plug-type connector (bent-back) 
           11  Plastic housing 
           12  Outer conductor 
           12   a, b  Conductor section 
           13  Dielectric 
           14 ,  14 ′,  15  Inner conductor 
           16  Inner conductor (coaxial cable) 
           17  Transition piece 
           18  Dielectric (coaxial cable) 
           19  Outer conductor (coaxial cable) 
           20  Press sleeve 
           21  Coaxial cable 
           22 ,  23  Latching tongue 
           24   a, b, c  Side wall (inner conductor  14 ,  14 ′) 
           25   a, b, c  Contact tongue (inner conductor  14 ,  14 ′) 
           26 ,  30  Recess 
           27  Opening (slot-like) 
           28  Lug 
           29  Projection 
           31  Latching point 
           32  Butt joint 
           33  Contact tongue 
           34  Plug axis 
           35  Longitudinal axis (coaxial cable) 
           36 ,  37  Section (dielectric) 
           38  Through-opening 
           39  Slot 
           40  Bevel 
           41  Clamping tongue 
           42  Contact fork 
           43 ,  44  Fork arm 
           45  Opening 
           46  Sleeve part 
           47  Plug part 
           48  Bore 
           49  Tip (conical) 
           50  Latching groove (circumferential)