Abstract:
The invention relates to an electrical connector for contacting at least one electrical lead and for connection with a complementary connector, to an electrical plug-in connection for connecting at least one electrical lead to an electronic component and to an assembly method for assembling such an electrical connector. In order to provide an electrical connector of the above type and an associated assembly method which ensures simple, inexpensive producibility on the one hand and robust and reliable contactability on the other hand, and which additionally enables the greatest possible miniaturization, the connector ( 100 ) comprises a housing ( 116 ), in which the contact element ( 120 ) is at least partially accommodated and on which there is arranged a terminal cover ( 118 ) for covering the terminal area ( 124 ), which cover comprises a first lid part ( 126 ) and a second lid part ( 128 ), which are so constructed that they may both be moved to expose the terminal area ( 124 ) during fitting of the electrical lead ( 104 ).

Description:
FIELD OF THE INVENTION 
   The present invention relates to an electrical connector for connecting at least one electrical lead to a complementary connector and an electronic component and to an assembly method for assembling such an electrical connector. More particularly, the present invention relates to electrical connectors which may be used in contacting igniters for an airbag of a motor vehicle. 
   BACKGROUND 
   Known airbag arrangements are used as automotive safety components in virtually every vehicle. An airbag arrangement comprises an inflatable restraining device, which is accommodated in the steering wheel, the instrument panel or the side door and is inflated by means of a gas generator in the event of sufficiently forceful deceleration. The gas generator is conventionally actuated by means of an explosive ignition device, which is also known as an igniter or squib and contains a gunpowder-like material. The igniter is ignited electronically in response to an electrical signal, which is emitted via electrical leads by an acceleration sensor or the like in the vehicle. Contact is established between these electrical leads and the igniter via a dedicated connector, also known as a “squib connector”. A known igniter socket arrangement, as known for example from EP 0 600 418 B1, comprises two connector pins, which are connected to the two electrical leads via contact elements of an electrical connector. 
   In the motor vehicles, especially at a safety-relevant location, such an electrical plug-in connection is generally produced to extremely high specifications for resistance to vibrations, temperature fluctuations or electromagnetic interference. 
   To fit the electrical connector on the electrical lead, it is conventional to connect a metallic contact element to the electrical lead and then fit it in a housing. As is known for example from EP 1 006 621 B1, the housing may comprise a hinged lid portion, which allows fitting of the contact elements. This solution has a disadvantage, however, that the crimping process, during which the contact elements are connected to the electrical lead, has to be performed before the contact element has been assembled in the housing. 
   The known solutions additionally exhibit a disadvantage that an additional tool is necessary in the case of bent contact elements to produce the angled contact. 
   It is therefore an object of the invention, among others, to provide a miniaturized electrical connector of the above type and an associated assembly method which ensures simple, inexpensive producibility on the one hand and robust and reliable contactability on the other hand. 
   SUMMARY 
   This and other objects are achieved by the invention which is based on the idea that the contact elements may be prefitted in the housing and connected to the electrical lead using the tools optimized for production of the electrical connection. The connector comprises a housing in which at least one contact element is at least partially accommodated and on which there is arranged a terminal cover for covering a terminal area of the contact element. The cover comprises a first lid part and a second lid part, which are so constructed that they may both be moved to expose the terminal area during fitting of the electrical lead. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention will be explained in more detail below with reference to the embodiments illustrated in the accompanying drawings. Similar or corresponding details are provided with the same reference numerals in the Figures, in which: 
       FIG. 1  is a perspective view of an electrical connection with a first connector according to the invention and a complementary connector; 
       FIG. 2  is a sectional view of the connector taken along section line  2 — 2  of  FIG. 1 ; 
       FIG. 3  is a side view of the electrical connector of  FIG. 1 ; 
       FIG. 4  is a side view of the connector of  FIG. 1  rotated by 90°; 
       FIG. 5  is a perspective view of a second lid part taken from above; 
       FIG. 6  is a perspective view of the lid part of  FIG. 5  rotated by 180°; 
       FIG. 7  is a perspective view of the housing with the first lid part taken from above; 
       FIG. 8  is a perspective view of the housing of  FIG. 7  rotated by 180°; 
       FIG. 9  is a perspective view of a two-path ferrite core; 
       FIG. 10  is a perspective view of a ferrite core for an individual contact element; 
       FIG. 11  is a perspective view of a contact element; 
       FIG. 12  is a perspective view of the housing with the contact elements fitted therein and the second lid part in the preliminary latched position; 
       FIG. 13  is a perspective view of the arrangement of  FIG. 12  rotated by 180°; 
       FIG. 14  is a cutaway perspective view of an individual contact element with the ferrite core of  FIG. 10 ; 
       FIG. 15  is a perspective view of the two-path ferrite core of  FIG. 9  with two contact elements fitted therein; 
       FIG. 16  is a perspective view of the contact elements and the ferrite core of  FIG. 15  on installation in the housing; 
       FIG. 17  is a perspective view of the arrangement of  FIG. 16  after bending of the contact elements into their final position; 
       FIG. 18  is a longitudinal sectional view through the arrangement of  FIG. 17  in the area of the contact elements; 
       FIG. 19  is a perspective view of the arrangement of  FIG. 17  before the second lid part is pushed on; 
       FIG. 20  is a top view of the arrangement of  FIG. 12  with exposed terminal areas; 
       FIG. 21  is a perspective view of the arrangement of  FIG. 20 , rotated by 180°; 
       FIG. 22  is a bottom view of the connector face of the arrangement of  FIG. 21 ; 
       FIG. 23  is a sectional view taken along section line  23 — 23  of  FIG. 22  immediately after production of the crimp connection; 
       FIG. 24  is the section of  FIG. 23  during displacement of the second lid into the final assembled position; 
       FIG. 25  is the section of  FIGS. 23 and 24  in the final assembled state; 
       FIG. 26  is a sectional view taken along section line  26 — 26  of  FIG. 25 . 
   

   DETAILED DESCRIPTION OF THE EMBODIMENTS 
     FIG. 1  shows an electrical connector  100  according to the invention, in this case an igniter connector, for mating with a complementary connector  102 , in this case a connector base in the form of a pin connector for the igniter of a gas generator, which is used in a motor vehicle to operate an airbag. Through the connector  100 , the two electrical leads  104  may be connected to the complementary contact elements  106 , in the form of plug pins, of the complementary connector  102 . Two latching projections  108 , which are in each case molded on to a latching arm  110 , cooperate with a latching recess  112  provided in the complementary connector  102  in such a way that the inserted electrical connector  100  can no longer become unintentionally detached. An actuating projection  114  is molded on each latching arm  110 , which projection allows the user to release the plug-in connection between the electrical connector  100  and the complementary connector  102 . 
   According to the invention, the housing  116 , made for example of plastic, of the electrical connector  100  comprises a terminal cover  118 , which covers the terminal area  124 , in which the electrical leads  104  are connected to contact elements  120 . 
   The section illustrated in  FIG. 2  along section line  2 — 2  clarifies the structure according to the invention of the connector  100 . The contact areas  122  of two metallic contact elements  120  ensure electrical contacting of the complementary contact elements  106  of the complementary connector  102 . Connection to the electrical lead  104  is produced in the terminal area  124  of the contact element  120  via a crimp connection. 
   According to the invention, the terminal cover  118 , which protects the terminal area  124  when finally assembled, comprises a first lid part  126  and a second lid part  128 . As will become clear with reference to the subsequent figures, the first lid part  126  and the second lid part  128  may be moved for fitting of the electrical lead  104  in order to fully expose the terminal area  124  of the contact element  120  for the crimping process of the contact element  120  held in the housing  116 . 
   In order to attenuate radio frequency interference, a ferrite core  130  is arranged on the contact element  120  in an area between the contact area  122  and the terminal area  124 . To ensure that the ferrite core  130  is secured in its position on the contact element  120 , two fixing elements  132  are provided on the contact element  120 . In the embodiment shown, the fixing element  132  is formed by a resilient arm, which fixes the contact element  120  in an opening of the ferrite core  130  by clamping. 
   Furthermore, the housing  116  comprises a rounded bending edge  134 , around which the contact element  120  may be bent in a bending zone  136  located between the contact area  122  and the terminal area  124 . The longitudinal axis of the contact area  122  then forms an angle of 90° with the longitudinal axis of the terminal area  124 . It goes without saying that other angles may also be established, depending on space requirements. 
   The electrical leads  104  may take the form, for example, of so-called FLR cables with a cross-sectional area of 0.5 mm 2 . 
     FIGS. 3 and 4  show side views of the electrical connector  100  according to the invention in the fully assembled state. These views clearly show the space-saving construction of the electrical connector  100  and the considerable degree to which it has been miniaturized. 
     FIGS. 5 and 6  are perspective views, which have in each case been rotated by 180° relative to one another, of the second lid part  128 . As will become clear with reference to the subsequent figures, this second lid part  128  may be displaced for the crimping process in a direction  138 , to expose the terminal area  124  from above. The first lid part  126  is attached pivotally to the housing  116  via film hinges  152  as shown in  FIG. 13 , such that it may be pivoted in a direction  140  out of the terminal area. 
     FIGS. 7 and 8  are perspective representations of the rest of the housing  116  with the first lid part  126 . The representation of  FIG. 7  also clearly shows the bending edges  134  required for bending the contact elements  120 , said bending edges  134  being provided at the edges of contact receptacles  142 . The view in  FIG. 8  of the connector face additionally shows clearly the keying provided by a guide projection  144  and a guide receptacle  146 , these preventing the connector  100  from being incorrectly inserted, and the latching arms  110  for fixing the connector  100  in the complementary connector  102 . The contact spacing of the connector face may be about 3.1 mm for example. 
     FIGS. 9 and 10  show perspective views of two possible embodiments of the ferrite core  130 . The ferrite core  130  may, as shown in  FIG. 9 , take the form of a two-path ferrite core, in which in each case two contact elements  120  are arranged. This embodiment has the advantage that the two contact elements  120  are already held for assembly by the ferrite core  130 . However, this variant exhibits the disadvantage that the contact spacing of the two contact elements, as arranged in the ferrite core  130  of  FIG. 9 , does not correspond to the contact spacing of the contact elements on a punched strip. If, on the other hand, individual ferrite cores  130  are used, as shown in  FIG. 10 , this has the advantage that the ferrite cores  130  may be fitted on the contact elements  120  on the punched strip in a reel-to-reel process. 
     FIG. 11  is a perspective view of a contact element  120  prior to fitting of the ferrite core  130 . As is clear from this illustration, the contact element  120  comprises a contact area  122 , which in the case of an electrical connector takes the form of a socket contact, and a terminal area  124 , which is designed to provide crimp contact with a lead. For this purpose, the terminal area  124  comprises a crimp zone for producing the actual electrical contact, and elements for strain relief. 
   Two fixing elements  132  are provided on the contact element  120  in the form of spring arms, which expand to fix the contact element  120  in place after insertion into the ferrite core  130 . 
     FIGS. 12 and 13  show two perspective illustrations, in each case rotated by 180°, of the electrical connector  100  in a preliminary latched position, as may be provided for example for delivery to a wiring manufacturer. As is visible in  FIG. 12 , the pivotal first lid part  126  is substantially parallel to the terminal areas  124  of the contact elements  120 , such that the crimp zones thereof are protected during transportation. Unintentional bending or deformation is not possible. The second lid part  128  is in a position in which the terminal areas  124  are exposed but the contact areas  122  of the contact elements  120  are concealed for protection. In this position, the latching arm  110  acts as latching means for the second lid part  128 . In addition, the wall elements  148  and  150  on the second lid part  128  prevent damage to the latching arms  110 . The film hinges  152  provide sufficient stiffness for the first lid part  126  for the position shown in  FIG. 13  to be maintained. 
     FIGS. 14 and 15  are perspective representations of the contact elements  120  each fitted in the ferrite core  130 , the partially broken-away representation of  FIG. 14  showing engagement of the fixing element  132  against the internal wall of the ferrite core  130  to fix the contact element  120  in the ferrite core  130 . For the following illustrations, which are intended to shed more light on the processes involved in assembly and contacting of the electrical connector  100 , the two-path ferrite core solution of  FIG. 15  was selected in each case. It goes without saying, however, that a greater or lesser number of contact elements  120  may be accommodated in one ferrite core  130 , depending on how many openings are provided. 
     FIGS. 16 to 18  are intended to explain fitting of the contact elements  120  in the housing  116 . First of all, the contact elements  120  are fitted in a ferrite core  130 . Then, as is symbolized by the arrow  154 , they are introduced into corresponding contact receptacles  142  in the housing  116 . The ferrite core  130  and the terminal areas  124  of the contact elements  120  are then bent round the bending edge  134  on the housing  116 , shown in  FIG. 18 , in direction  156 . The contact elements  120  thus have the necessary bent shape and are installed in optimum manner in the housing. 
   As shown in  FIG. 19 , the second lid part  128  is then pushed on in direction  138 . Once the latching arms  110  have been latched together with the first latching receptacles  158 , the electrical connector  100  finds itself in the preliminary latched position shown in  FIG. 12 . The electrical connector  100  may be delivered in this state to a wiring manufacturer. 
     FIGS. 20 and 21  show the connector  100  immediately after the crimping process. In order to allow unimpeded access to the terminal areas  124  of the contact elements  120  from all sides for the crimping process, the first lid part  126  is folded in direction  140 . In this way, the crimp area is freely accessible and a wiring manufacturer can perform crimping in a wholly conventional manner. In particular, the tools do not have to adapt. It is possible to produce the two contacts either simultaneously or separately. To do this, the first lid part  126  has to be held in the folded-back position, as shown in  FIG. 21 , since the film hinge  152  exhibits a certain restoring force. 
     FIGS. 22 to 25  explain the method steps performed from connection of the electrical leads  104  until full assembly is achieved. According to the invention, the second lid part  128  is here used as an actuating and securing element for the first lid part  126 . Force acting on the second lid part  128  displaces it in direction  162 , as is clear from the sectional illustrations, the first lid part  126  thereby being pivoted in direction  141  back out of its bent position until the terminal area  124  is covered on one side. At the same time, the second lid part  128  also covers the terminal area  124  on the opposing side. Through latching together with the second latching receptacle  160  by the latching arm  110 , the second lid part  128  is held precisely in this position. A safeguard against unintentional displacement of the second lid part  128  even in the event of the latching arms  110  being actuated is provided by the latching elements  164 , which cooperate with latch openings  166  to secure the second lid part  128  to the housing  116 . As is clear from sectional illustration  26 — 26  of  FIG. 26 , the first lid part  126  is held secure via appropriate guide projections on the second lid part  128 . 
   In the position shown in  FIG. 25 , showing final fitting to a cable harness, the contact elements  120  are thus locked in place and the terminal area  124  is fully protected. In addition to easy, efficient fitting, particularly reliable electrical contactability may also be ensured. The electrical connector  100  according to the invention may be used without further modification by any desired wiring manufacturer and fitting to the electrical leads  104  is greatly simplified. 
   A particularly reliable electrical connection may thus be achieved, as well as simplicity of assembly. With the solution according to the invention, no additional components are required for the assembly process after connection of the contact elements to the electrical leads. The preliminary latched position of the individual components intended for transportation of the contact elements not as yet connected additionally offers optimum protection of the sensitive contact and crimp areas at such a time. Furthermore, the solution according to the invention offers the advantage that the connector exhibits a particularly small structural size.