Abstract:
In order to interlock an electric contact within an insulating body for a plug-type connector, the invention provides integral clips that are axially spaced apart from one another and on the edges of which the electric contact can be interlocked within a through-opening on the mating side and on the connection side. The invention also proposes a method in which two mould cores that encompass one another and form the through-opening can be removed from the through-opening in opposite directions after the injection-moulding process.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The invention pertains to a method for manufacturing a locking device for an electric contact in a through-opening and an adjacent insertion compartment in an insulating body by means of an injection-moulding tool for a plug-type connector as well as to a locking device for an electric contact in a through-opening and an adjacent insertion compartment in an insulating body. 
   2. Description of the Related Art 
   A locking device of this type is required for holding an electric contact in the opening of an insulating body in a captive fashion. 
   It is common practice to fix known electric contacts that are usually realized in the form of crimp contacts and arranged within an insulating body in a captive fashion by means of corresponding locking means (e.g., a locking clip). 
   For example, DE 15 15 831 discloses a device for holding exchangeable contact elements in electric plug-type connectors, wherein a locking cone secures the contact element in an insulating body. 
   In this system, it is disadvantageous that at least one additional locking means in the form of a snap ring, a locking ring or a snap hook is required in order to fix the electric contacts in position. 
   SUMMARY OF THE INVENTION 
   The invention consequently is based on the objective of developing a device that makes it possible to simply lock an electric contact in a through-opening of an insulating body without auxiliary means. 
   This objective is initially attained with a method in which two mould cores, namely a first mould core and a second mould core, partially encompass one another and are arranged within an injection-moulding tool that forms a housing, wherein said mould cores can be respectively removed from the through-opening in axially opposite directions after the injection-moulding process, and wherein the mould cores are shaped such that clip-on means featuring clip-on edges are formed on both ends of the through-opening. 
   The aforementioned objective is also attained in that the through-opening respectively features a clip-on means that protrudes into the interior on both ends, wherein the clip-on means are arranged offset relative to one another by 180°, and wherein the electric contact can be interlocked within the regions of the clip-on means that are axially spaced apart from one another. 
   The advantages attained with the invention can be seen, in particular, in that a conventional electric contact realized in the form of a pin or a socket contact can be directly interlocked in the inventive embodiment of the insulating body without requiring an additional separate holding or locking element. 
   In contrast to known arrangements, it is advantageous to fix the contact in a through-opening that accommodates the contact on both sides, namely with correspondingly designed clip-on means. 
   For this purpose, a stop pin is provided on one side of the through-opening and a locking block is provided on the other side, wherein the contact can be inserted and interlocked between the stop pin and the locking block. During this process, a circumferential groove arranged on the electric contact engages with an undercut on the locking block that is provided with a clip-on edge. 
   The locking block features a clip-on edge with an angle of 90° while the adjacent angle of the clip-on edge of the electric contact forms an angle between 80° and 85°, preferably 83°, relative to the groove plane. 
   The advantage in comparison with a conventional 90°-angle can be seen in that the locking block is integrally arranged on an exposed overhang of the wall of the through-opening and the overhang may be bent radially outward while the contact is subjected to a load during the mating process such that there is a risk of the contact sliding out of the locking region. 
   In the preferred embodiment, the steeper slope of the clip-on edge of the contact engages on the clip-on edge of the locking block. 
   During the removal of the electric contact from the through-opening, this bending effect is preferably utilized in the form of an extreme excursion of the overhang. 
   For this purpose, a disassembly tool is inserted between the crimping region of the electric contact and the slope realized on the locking block. The overhang can then be displaced radially outward until the contact is exposed and can be pulled out with the cable crimped thereon. In this respect, the option of providing locking elements on two sides could not be considered until now because a corresponding tool for producing openings and clip-on means of this type was not available. 
   A simple and inexpensive interlock between electric contacts and a connector housing can be produced with one advantageous development of this method, in which two mould cores that at least regionally interpenetrate are used for moulding the through-opening and the clip-on means. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     One embodiment of the invention is illustrated in the figures and described in greater detail below. The figures show: 
       FIGS. 1   a  and  1   b  are mounting techniques according to the state of the art; 
       FIG. 2  a longitudinal section through an insulating body with an electric contact, 
       FIG. 3  a longitudinal section through an insulating body with an electric contact and an electric cable, as well as a disassembly tool, and 
       FIG. 4  a longitudinal section through an insulating body with mould cores. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIGS. 1   a ,  1   b  show the current state of the art for locking electric contacts in connector housings.  FIG. 1   a  shows a longitudinal section through an insulating body  1  with a contact  20  that is inserted into an opening  2  in the mating direction, namely against a clip-on edge  11 , and locked in position by means of a locking element  17  that is attached from the mating direction and abuts the stop  11  on the opposite side. In this case, the locking element is realized in the form of a sleeve-shaped washer that is supported on a collar  18  of the contact and fixes the contact in the opening. 
     FIG. 1   b  also shows an electric contact  20  that is inserted into an opening  2  against a clip-on edge  11  in the mating direction. The contact  20  is locked in position by means of a locking element  17 ′ that is realized in the form of a clip-on arm, wherein said locking element also acts upon a collar of the contact in the mating direction and thusly fixes the contact in the opening  2 . 
     FIG. 2  shows a longitudinal section through an insulating body  1  with an electric contact  20  that is inserted into a through-opening  2  and realized in the form of a socket in this case, wherein said contact features a contact zone  23  that is provided with several longitudinal slots  24 , as well as a crimping region  25  that is separated from said contact zone by a circumferential groove  21 . 
   The electric contact  20  is fixed on both sides with hook-shaped clip-on means that form an integral part of the ends of the through-opening  2 . 
   The clip-on means are realized in the form of a U-shaped stopping bow  10  on the mating side  4  of the circular through-opening  2 , as well as in the form of a locking block  13  on the opposite connection side  5 . 
   In this respect, the invention proposes to arrange the two clip-on means  10 ,  13  that only protrude into the through-opening regionally such that they are radially offset by approximately 180°. 
   This means that the contact  20  is securely fixed in position, namely even if the stopping bow  10  is not realized completely circular within the through-opening  2  and the locking block  13  has approximately half the width of a through-opening. 
   The stopping bow is shaped such that it extends from an upper maximum extension protruding into the interior to the lower part of the through-opening, namely in a symmetric fashion on both sides, and then ends in the wall without a transition. 
   When the contact is inserted into the through-opening  2  in the mating direction  4 , in this case from the left to the right, the end on the mating side adjoins the “upper” left clip-on edge  11  of the front stopping bow  10  while the hook-shaped “lower” right locking block  13  penetrates into the circumferential groove  21  of the electric contact  20 . The locking block furthermore features a slope  15 , the function of which is explained further below. 
   The circumferential groove  21  of the contact has the peculiar feature that at least the clip-on edge of the undercut  22  that acts upon the locking block is angled relative to the base surface of the groove by an angle between 80° and 85°, preferably 83.5°. 
   When the electric contact  20  is subjected to an axial load, i.e., when a connection is produced with a mating connector, this provides the advantage that the load is transmitted to the locking block  13 . Since the locking block is arranged on the overhang  7 , there is a certain risk of moving the locking block such that the contact slides out of the through-opening. 
   Due to the steeper angle, the undercut  22  is wedged against the lower end of the clip-on edge  14  and largely prevents the overhang  7  from moving. 
   An insertion compartment  3  situated adjacent to the locking block  13  accommodates, among other things, the crimping zone of the electric contact with the corresponding electric cable and has larger dimensions than the through-opening  2 ; these larger dimensions not only serve for accommodating a disassembly tool  40  in addition to the electric conductor  27 , but also for realizing part of the wall of the through-opening  2  in the form of an exposed overhang  7 . 
   If the disassembly tool  40  is inserted between the slope  15  of the locking block  13  and the crimping zone  25  of the contact  20  as shown in  FIG. 3 , the locking block is pressed down due to the exposed overhang  7 . The resulting lever effect causes the point of the hook-shaped locking block  13  to disengage from the circumferential groove  21  of electric contact  20  and the contact  20  can be pulled out of the through-opening  2  with the cable  27  already crimped thereon. 
   The simplified schematic representation according to  FIG. 4  shows the shape of the two clip-on means  10 ,  13  for interlocking the electric contact  20  in the through-opening  2  of the insulating body. 
   In this case, the insulating body  1  with the through-opening  2  and the merely indicated mould cores  30 ,  35  is illustrated in the form of a longitudinal section at the time at which the plastic mass injection-moulded thereon has cooled. 
   The two mould cores  30 ,  35  have different shapes, wherein a nearly oval inner core  30  is at least regionally encompassed by a U-shaped outer core  35  such that the two oppositely arranged mould cores form an approximately circular through-opening  2 . 
   In this case, the front sides  31 ,  36  of the mould cores  30 ,  35  form the two clip-on edges of the clip-on means, wherein the front side  31  forms the “rear” clip-on edge  14  on the locking block  13  and the front side  36  forms the front clip-on edge  11  on the stopping bow  10 . 
   The integral elements  32  and  37  of the mould cores serve for producing the slopes  12  on the stopping bow  10  and the slope  15  on the locking block  13  during the injection-moulding process. 
   Since the core  35  is designed such that it encompasses the oval core  30 , the stopping bow  10  can transform into the lateral region of the inner wall from its maximum spacing without a transition. 
   After the injection-moulding process, the two cores are removed from the through-opening in directions that are offset by 180°.