Abstract:
The invention concerns an electrical plug connector with a housing having a housing body and a trunk projecting therefrom for receiving electrically connected contact elements for establishing contact with corresponding contact portions of an associated receptacle as well as with spring-acting catch arms on the trunk for making the housing fast in corresponding recesses of the receptacle.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The invention concerns an electrical plug connector, in particular for use between a receptacle (ignitor) and an electrical control device for a restraint system in motor vehicles, by way of example an airbag.  
           [0003]    2. Description of the Prior Art  
           [0004]    A plug connector of the above type is found by way of example in DE 198 40 726 C2.  
           [0005]    The very limited overall size (for example, length: 2 to 3 cm; width: approx. 1 cm; height: 0.1 to 1.0 cm) creates design problems.  
           [0006]    This applies in particular with reference to a latching of plug and receptacle, with the contact elements of the components having to contact reliably in the locked state. In like manner, the plug and receptacle must not release from each other unintentionally.  
           [0007]    In the case of the plug connector according to DE 198 40 726 C2, the problem is solved in that the locking element is situated in a pre-assembled starting position in a raised position against the effect of a spring, and in order to lock plug connector and receptacle, it can be brought against the effect of the spring into a maximum plug position in which the catch arms can be moved freely. After the latching of plug connector and receptacle, the locking element however moves as a result of the spring effect on its own back into its starting position in which the locking element then secures the catch arms against unintended release (so-called secondary locking).  
           [0008]    It is apparent that as a result of the small overall size, the path of the spring is very short.  
           [0009]    With the present invention, an alternative structural shape for a plug connector is to be offered that fulfills the following requirements: the locking element and the housing of the plug connector should be brought in one step into the end position (locking position with respect to the receptacle). In this function position, the plug connector should be secured against unintended release.  
           [0010]    Typically, thus also in the case of the plug connector according to DE 198 40 726 C2, the plug connector has a housing with a housing body and a trunk projecting from it. The trunk serves to receive the electrically connected contact elements for making contact with the corresponding contact parts of the receptacle. The catch arms are linked to the housing body and run parallel to the trunk and with their free ends in the direction toward the trunk end. Upon being introduced into the receptacle, the front end of the catch arms in the direction of the plug contact run onto corresponding parts of the receptacle and are shifted “toward the interior,” i.e. in the direction of the trunk. Upon further introduction of the plug connector into the receptacle, the catch arms finally spring back and into the locking position. In this locking position (function position) the catch arms are secured through the locking arms of the locking element (so-called secondary locking), with these locking arms filling the space between trunk and catch arm. This measure presupposes a corresponding tracking of the locking element.  
         SUMMARY OF THE INVENTION  
         [0011]    The invention takes an opposite path. While the plug connector also comprises catch arms, they are at the end of the trunk, i.e., precisely the opposite in comparison with the state of the art. “At the end of the trunk” here means that the catch arms are linked “at the lower free end section” of the trunk, i.e., there can well be a space between the catch arms and the face of the trunk. From the point of linking, the catch arms run at a distance from the trunk (in order to permit the desired spring effect) in the direction toward the housing body.  
           [0012]    This arrangement of the catch arms creates the possibility of arranging their “pivot point”/“center of gravity” in the direct vicinity of the linking zone. Expressed differently, a relatively long end section of the catch arms can be swung over a relatively wide area. At the same time, the latching point of the catch arms can be provided in the associated receptacle relatively close to the linking point. As a result of this measure, it is also possible to achieve secure latching of the plug connector in the receptacle even without means for secondary locking, in particular if the catch arms in their function/locking position run more or less parallel with each other (and thus in axial direction of the trunk).  
           [0013]    This arrangement creates the further possibility of mounting a locking element fully on the housing of the plug connector and thus bringing housing and locking element at the same time into contact position with the receptacle. Because the locking element no longer has the function of creating a secondary locking for the catch arms of the housing after the locking of the housing in the receptacle, a relative shifting of housing and locking element during assembly becomes no longer necessary.  
           [0014]    The locking element should nevertheless be (in like manner) locked with respect to the receptacle. In addition, it can fulfill the function of opening or closing a shunt in the area of the contact parts/contact elements of plug connector and receptacle. In addition it can be used to release the plug connector again from the locking position with respect to the receptacle.  
           [0015]    Accordingly, the invention in its most general embodiment form concerns an electrical connector plug, in particular for use between a receptacle (ignitor) and an electrical control device for a restraint system in motor vehicles, with the following features:  
           [0016]    a housing with a housing body and a trunk projecting from it for receiving electrically connected contact elements for contacting with corresponding contact parts of the receptacle,  
           [0017]    catch arms on the trunk with spring action for fixing the housing in corresponding recesses of the receptacle,  
           [0018]    the catch arms are joined at the trunk end and from there run, at a distance from the trunk, in the direction toward the housing body,  
           [0019]    a locking element that can be plugged onto the housing,  
           [0020]    the locking element comprises locking arms with spring action for fastening to at least one of the elements receptacle and housing.  
           [0021]    The locking arms of the locking element can project out from a base portion. This base portion can comprise a simple plate. From one or several edges of the plate, wall sections can project out resulting in a type of frame for the base portion.  
           [0022]    The locking arms of the locking element can, in the connected condition of the locking element, pass in the area of the catch arms of the housing. Ordinarily the catch arms are arranged at two opposite sections of the trunk (thus offset by 180° with respect to each other). It is also possible for several catch arms to be arranged one beside the other on each side. If several catch arms are arranged on each side, the locking arms by way of example can be received between adjacent catch arms. The locking arms, however, can also be movable along slots that are formed in the catch arms.  
           [0023]    It should be pointed out again at this point that the catch arms on the one hand and the locking arms on the other hand are arranged “inversely,” specifically the catch arms in the area of the end of the trunk and the locking arms in the area of the housing body or of the connection area of the trunk to the housing body. When the locking element is plugged onto the housing, the free ends of the locking arms accordingly pass in the opposite direction to the free ends of the catch arms.  
           [0024]    The described linking of the catch arms makes it possible to allow the catch arms in the function position to run from the plug connector and receptacle parallel to the trunk, with the exception, of course, of the connection area. If the catch means of the catch arms then are arranged in an area of the catch arms that is adjacent to the area at which the catch arms are linked to the end of the trunk, the possibility described above arises of situating the “pivot area” of the catch arms very far in the direction of the end of the trunk. Expressed differently: the area of the catch arms between the catch means and the housing body is greater than the area between the catch means and the joining parts.  
           [0025]    As a result of the described arrangement of the pivot point toward the end of the trunk, the plug connector can no longer be removed from the receptacle without tools.  
           [0026]    In order to nevertheless be able to separate plug connector and receptacle, one embodiment form of the invention provides that the locking member be arranged so as to be shifted relative to the housing, specifically in axial direction of the trunk. For this purpose, the locking member can be capable of being shifted along a path that is specified by a window that is formed in the locking element (in the example in the frame mentioned above).  
           [0027]    The specific arrangement of the catch arms and of the locking arms creates the possibility of matching each to the other such that the catch means of the locking arms are fixed in the same recesses of the receptacle as the catch means of the catch arms.  
           [0028]    If the catch means of the locking arms are arranged in the free end area of the locking arms (for example through corresponding thickenings), a further result is that, after the locking element has been fully plugged onto the housing, these catching means are situated approximately in the same place at which the catch arms have their catching means (by way of example external thickenings).  
           [0029]    As mentioned earlier, the locking element can comprise a plug arm that has a length such that in the function position of housing and receptacle it opens a shunt that is effective between the contact parts and/or contact elements.  
           [0030]    As a result of the parallel shifting of housing and locking element, the shunt thus also is released in a single work step upon assembly of plug connector and receptacle.  
           [0031]    In this embodiment form, if the plug connector should become removed again out of the receptacle, the shunt can nevertheless be activated again before the housing is removed from the receptacle. For this purpose it is provided that the locking element can be shifted along a path that can be specified by a window which is formed in the locking element. The locking element is first withdrawn from the housing. In this process, the plug arm is also brought away and the shunt is activated. After reaching the maximum shift position, the locking element upon being further pulled away brings the housing with in that the catch arms are pushed away (pushed against each other) by the locking element whereby they are released from the recesses of the receptacle.  
           [0032]    For guidance of the catch arms, the catch arms, in the function position of housing and receptacle, can engage with their free ends in openings that are formed in the locking element. The catch arms can then, upon the plug connector being pulled out of the receptacle, extend to the limits of these openings.  
           [0033]    Further features of the invention are found in the features of the subclaims as well as the other application papers. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0034]    The invention will be explained in greater detail below on the basis of an exemplary embodiment, with drawings showing the following in schematic representation:  
         [0035]    [0035]FIG. 1 shows a longitudinal section through a plug connector before its being latched in a receptacle,  
         [0036]    [0036]FIG. 2 shows a view according to FIG. 1 with the plug connector and receptacle being latched,  
         [0037]    [0037]FIG. 3 shows a view according to FIG. 1 with the plug connector being freed again from the receptacle,  
         [0038]    [0038]FIG. 4 shows a longitudinal section offset by 90° to the depiction according to FIG. 1,  
         [0039]    [0039]FIG. 5 shows a longitudinal section offset by 90° to the depiction according to FIG. 2,  
         [0040]    [0040]FIG. 6 shows a longitudinal section offset by 90° to the depiction according to FIG. 3. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0041]    In FIG. 1, a plug connector is identified with  10  and an associated receptacle (ignitor) is designated with  50 .  
         [0042]    The plug connector comprises a two-part housing with one component of a housing upper shell being identified with  12  while  14  describes a trunk that is one piece with a housing lower shell  13  (FIG. 4).  
         [0043]    The trunk serves to receive contact springs  16  (FIGS. 4 through 6) that can be electrically connected in known manner.  
         [0044]    From free end section  14   e  of trunk  14 , linked to sections situated opposite each other are respective catch arms  18  (in FIG. 1: at the lower end of trunk  14 ). Catch arms  18  extend in the depiction according to FIG. 1 upward (in the direction of upper shell  12  of the housing). Catch arms  18  have on the outside, shortly above a pivot area  18   s , thickenings  18   v  which assume the function of a catch means.  
         [0045]    In contact with upper shell  12  of the plug connector housing is a locking element  20 . The locking element  20  comprises a base portion  20  with a base plate  22   g . Running vertically from base plate  22   g  are three wall surfaces that in FIG. 1 are identified with  22   w   1 ,  22   w   2  and in FIG. 4 are identified with  22   w   3 , with a wall opening (window)  22   o   1 ,  22   o   2 ,  22   o   3  being provided in each wall surface opening (window).  
         [0046]    Extending from wall surfaces  22   w   1 ,  22   w   2  essentially vertical to base plate  22   g  are locking arms  24 . Arranged at the free ends of locking arms  24  on the outside are thickenings  26  which in FIG. 1 can be only partly discerned because they are hidden by catch arms  18 .  
         [0047]    Initially locking element  20  is plugged onto upper shell  12  of the housing body until base portion  22  lies on upper shell  12 . Both are then introduced together into an opening  52  of the receptacle. As soon as thickenings  18   v  of catch arms  18  have come into contact with sloping surfaces  56  of the interior wall of receptacle  50 , catch arms  18  pivot against trunk  14  (FIG. 1) and locking arms  24  are pressed away at the same time.  
         [0048]    As soon as the thickenings  18   v  or  26  have reached corresponding recesses  58  on the inner wall of receptacle  50 , catch arms  18  and locking arms  24  spring into these recesses  58 . The locking position/function position of plug connector  10  and receptacle  50  is attained as is depicted in FIG. 2.  
         [0049]    In this state, catch arms  18  extend for the most part parallel to trunk  14  (in axial direction of the trunk). Plug connector  10  no longer can be separated from receptacle  50 . Pivot area  18   a  is so deep that if one tries to draw the plug connector housing out of the receptacle, the free ends of catch arms  18  push outward in opposite direction and thereby reinforce the latching even more.  
         [0050]    Freeing of plug connector  10  from receptacle  50  is possible only with the aid of locking element  20 . As depicted in FIG. 3, the latter is released from upper shell  12  of the housing body, with the maximum shift path being specified by means of the corresponding height of window  22   o   3 . Locking arms  24  in this process are released from recesses  58 , while catch arms  18  initially still remain in recesses  58 . When locking element  20  is pulled out, catch arms are pressed away toward the interior (FIG. 3) as soon as lower limits  22   u   1 ,  22   u   2  of openings  22   o   1 ,  22   o   2  contact catch arms  18  thickened at their free end area  18   o.    
         [0051]    After this, plug connector  10  can be completely released from receptacle  50 .  
         [0052]    When locking element  20  is drawn out, a short circuit  60  at the same time is again activated, i.e., is brought against contact pins  62  in the area of receptacle  50 , with short circuit  60  being configured as a leaf spring. It can be seen from FIG. 6 how said short circuit  60  is canceled upon insertion of locking element  20  specifically in that a plug-in arm  22   s  that projects vertically from base plate  22   g  is brought against short circuit  60  and presses it away laterally (and thus releases it from contact pins  62 ).