Patent Publication Number: US-6709289-B2

Title: Electrical plug connector

Description:
FIELD OF THE INVENTION 
     The invention relates to an electrical plug connector having a quick-action interlock, having a first connector element and having a second connector element, which are connected to one another by means of a coupling member and form an inner conductor and an outer conductor, with an outer conductor part of the second connector element forming an electrical contact at the end, and with a resilient contact element being arranged between the first connector element and the second connector element. 
     BACKGROUND OF THE INVENTION 
     A plug connector of this type has been disclosed in the prior art in WO 00/05785. In this plug connector, the coupling member has a locking ring which detachable connects the two connector elements to one another. An unlocking sleeve is moved axially, in order to release the connection. This raises the locking ring out of an external groove on the second connector element. When the two connector elements are being mated, the locking ring automatically latches into said external groove on the second connector element, and locks it to the other connector element. A sleeve with spring tongues is provided in order to compensate for tolerances in the coupling member, one end of which sleeve is firmly connected to the first connector element, while its other end is latched on the inside to the spring tongues on the second connector element. This plug connector has the particular disadvantage that the physical design is comparatively complex. In particular, said sleeve is comparatively complex to produce and to install. 
     BRIEF SUMMARY OF THE INVENTION 
     The invention is based on the object of providing an electrical plug connector of said type, which can be produced mechanically more easily and which nevertheless has good RF characteristics. 
     For an electrical plug connector of said type, the object is achieved in that the contact element is an annular disc, which rests on the outer conductor parts, between them, with axial stress, and forms circumferential, closed contact surfaces. Trials have shown that the plug connector according to the invention has very good RF characteristics and, in particular, has good passive intermodulation and little RF emission. The production costs are particularly low, with very good RF characteristics if, according to one development of the invention, the contact element is in the form of a cup spring. A contact element such as this can be produced at very low cost. Said RF characteristics are particularly good if, according to one development of the invention, the contact element makes contact with said end face along a circumferential closed circular line. The contact element advantageously makes contact with both connector elements along a closed circumferential circular line. This results in a precisely defined contact with good passive intermodulation and RF emission. A major advantage of the invention is also that axial angle discrepancies between the two connector elements of up to about 1° do not adversely affect the RF contact. The contact is thus distinguished by good bending robustness. 
     According to one development of the invention, the contact element has an inner collar and is designed such that an axial residual force or residual stress always exists. This ensures that an axial stress is maintained irrespective of the tolerance discrepancies of the coupling member. The contact element is thus designed such that it cannot be flipped over, as is normally possible with cup springs. 
     One development of the invention provides for the contact element to be mounted on the outside of an insulator. This insulator is preferably arranged in the first connector element, and is arranged between the inner conductor part and the outer conductor part. During assembly, the contact element can easily be pushed onto this outer conductor. Said collar and the assessment on the inner edge of the contact element considerably simplify this assembly process. The contact element is preferably inserted into an external groove on the insulator. 
     Particularly good RF characteristics are obtained if, according to one development of the invention, the end surface of the outer conductor part of the second connector element is sharpened to form a circumferential linear contact surface. The contact area between the contact element and the second connector element is then always the same, and is precisely defined. 
     Further advantageous features can be found in the dependent patent claims, in the following description and in the drawing. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     An exemplary embodiment of the invention will be explained in more detail in the following text with reference to the drawing, in which: 
     FIG. 1 shows a partial cross section through a plug connector according to the invention, 
     FIG. 2 shows a section through the first connector element, 
     FIG. 3 shows a detail, on an enlarged scale, from FIG. 1, 
     FIG. 4 shows a section through a contact element, and 
     FIG. 5 shows a three-dimensional view of the contact element shown in FIG.  4 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1 shows an electrical plug connector  1  which has a first connector element  2  and a second connector element  3 , which respectively form an outer conductor  9  and an inner conductor  10 , respectively. The two connector elements  2  and  3  are detachably connected to one another by means of a coupling member  26 . In a manner known per se, the coupling member  26  has a locking ring  5 , which engages in an external groove  6  on the second connector element  3  and projects on a shoulder  29  of the first connector element  2  and on a holding edge  7 . In order to release the lock, a locking sleeve  4  is pushed in the direction of the arrow  28 , and thus from right to left, in FIG.  1 . By means of a circumferential inner edge  30 , the locking ring  5  is pushed out of the external groove  6 , thus releasing the lock. When the two connector elements  2  and  3  are being mated, the locking ring  5  automatically latches in the groove  6 . 
     In order to compensate for the tolerance of the coupling member  26  and in order to achieve good RF characteristics, a contact element  16  is provided, which is arranged between the outer conductor part  11  of the first connector element  2  and an outer conductor part  12  of the second connector element  3 . The contact element  16  forms a cup spring and has a conical annular disc  23  which, at its edge, has a collar  22  which extends axially and whose wall thickness is several times smaller than the width of the annular disc  23 . The contact element  16  is composed of a resilient metal, for example of a suitable copper alloy. 
     As can be seen particularly clearly in FIG. 3, the contact element  16  is arranged between one end face  21  of the outer conductor part  12  and a contact surface  20  of the outer conductor part  11 . With respect to the outer conductor part  12 , the contact element  16  forms a circumferential linear and closed contact surface A. With respect to the outer conductor part  11 , the contact element  16  likewise forms a closed, circumferential and circular contact surface B. As is shown in FIG. 3, these two surfaces A and B are arranged radially at a distance from one another. The front end  12   a  of the outer conductor part  12  is sharpened, as can be seen, on the end face  21 , so that the end surface  21  rests on the contact element  16  only in the area of the closed circular surface A. In the extreme, the contact element  16  can be placed flat against the surface  20 . Even in this extreme, a residual force remains and hence, even in this situation, the contact element  16  exerts an axial stress on the two outer conductor parts  11  and  12 . As mentioned, the axial stress on the contact element  16  compensates for the tolerance of the coupling member  26 . 
     The contact element  16  is mounted on an insulator  15  which, in a manner known per se, holds an inner conductor part  13  which, as shown in FIG. 1, is connected to an inner conductor part  14  in the form of a spring socket. As is shown in particular in FIG. 3, a circumferential groove  19  is incorporated in the outside of the insulator  15 , and the contact element  16  is inserted into this circumferential groove  19 . The contact element  16  is thus mounted on the insulator  15 , although this is not essential. In order to install the contact element  16 , it is pushed onto the insulator  15 , which is made considerably easier by the collar  22 . The fitting of the contact elements  16  may also be automated. 
     The two connector elements  2  and  3  are sealed with respect to one another by means of a sealing ring  17 , which is inserted into an internal groove  18  in the outer conductor part  11 . This sealing ring  17  rests on the outside of the outer conductor part  12 , as can be seen. FIG. 2 shows the first connector element  2  with the contact element  16  in the unstressed rest position. When the second connector element  3  is now inserted into the first connector element  2 , then the shoulder  7  spreads the locking ring  5  which, in the end, latches into the groove  6 . At the same time, the sealing ring  17  is compressed, and the contact element  6  is elastically deformed from the dashed-dotted shape shown in FIG. 3 to the form shown by solid lines. The contact element  16  is thus stressed and exerts an axial force which presses the locking ring  5  against the shoulder  7  and against the holding edge  8 . When the connection is released, then the contact element  16  returns to the rest position shown in FIG.  2 .