Abstract:
A female plug coupling having three plug openings to accommodate the current conductors and the ground conductor of a male plug coupling. The female plug coupling includes an insert constructed whereby all the crimp connections lie in a single plane to facilitate crimping on the conductor ends to the female plug coupling.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application is a National Stage Application under 35 U.S.C. §371, of PCT International Patent Application Number PCT/EP99/06895, (published as International Publication Number WO 00/21162), filed Sep. 17, 1999, that designated the United States, which stems from German Application No. 198 47 067.3, filed Oct. 6, 1998. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a female plug coupling having three plug openings. More particularly, the present invention relates to an improved insert for a female plug coupling having three plug openings. 
     2. Description of the Related Art 
     Such plug couplings are in use in the USA and Japanese markets. For example, a plug coupling is shown in U.S. Pat. No. 5,647,751. According to the state of the art, female plug couplings consist of a two-part plastic material body in which the crimp connection pins for the conductor ends are inserted. The conductor ends are crimped on, i.e., fixed on, to the crimp connection pins and, the insert is extrusion-coated and thus forms the core of a grip body. The face side of this grip body has three plug openings arranged in a triangle to one another in a complementary manner to the contact pins of the connector plug. One of the connector plug contact pins is round, and the other two (current conducting) contact pins are rectangular. 
     In the manufacturing of the inserts for the plug coupling, problems have arisen in connection with the crimping-on of the conductor ends to the effect that it has proved difficult to perform the working step CRIMPING with a simple tool in a single operation. By reason of the arranging and assigning of the crimp connection ends in different topological planes, there is involved on the one hand a complicated tool and, on the other hand, different and in part diametrical force directions. 
     SUMMARY OF THE INVENTION 
     The present invention provides a plug coupling in which all the crimp connections lie in one and the same plane and which, therefore, can be executed in one operation with a simple one-piece tool. 
     In this regard, the special form of execution chosen for the crimp connection of the ground conductor has additionally proved to be especially advantageous, as the plugging force for the corresponding contact pin of the connector plug is relatively slight because of the shortness of the contact length of the plugging path. Both for the current conductor contact pins, and also for the protective conductor contact pin, there have been provided on the corresponding parts of the plug, coupling lugs or lashes which provide introduction aids. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention is explained in the following with the aid of the drawings, wherein: 
     FIG. 1 is a representation of an exemplary base body; 
     FIG. 2 illustrates the crimp connection pins for the current conductors and the ground conductor to be installed in the base body illustrated in FIG. 1 next to one another; 
     FIG. 3 illustrates the base body according to FIG. 1, with the crimp connection pins according to FIG. 2 installed therein; 
     FIG. 4 provides an outside view of a cover cap of the insert of the present invention; 
     FIG. 5 provides an inside view of the cover cap according to FIG. 4; 
     FIG. 6 illustrates a complete insert for a plug coupling composed of the base body according to FIG. 1, with the crimp connection pins positioned therein as illustrated in FIG. 3, and of the cover cap according to FIG.  4  and FIG. 5; 
     FIG. 7 illustrates the installation according to FIG. 6 with the cover cap removed to illustrate a crimped-on supply line; and 
     FIG. 8 illustrates a finished plug coupling including the insert of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     In FIG. 1 there is represented a base body  1  made of hard elastic plastic material. Base body  1  includes three incisions  2  for the installing of the crimp connection pins  30 ,  31  (see, e.g., FIGS.  2  and  3 ). Opposite incisions  2 , base body  1  includes a face wall  5 , which abuts raised edges  6 ,  7  of the base body  1 . The base body  1  has a plurality of molded-on pins  8  and columns  9  and further includes separated insertions channels  11 ,  12 ,  13  formed between the front edge of base body  1  (i.e., the edge having incisions  2  formed therein), and face wall  5 . Opposite the face wall  5  there are molded two higher columns  14 ,  15 , the importance of which will be described later. 
     In the face wall  5 , in the lower zone adjacent to the base bottom  16 , there are provided two rectangular passage openings  17 , into which the current conductor contact pins of the connection plug are introduced. In the upper zone there is provided a passage opening  18  for the round contact pin (ground pin) of the connector plug. 
     FIG. 2 shows, next to one another in quasi-assembled position, a crimp connection pin  30  for a current conductor, a crimp connection pin  31  for the ground conductor, and a (second) crimp connection pin  30  for the second current conductor. Each crimp connection pin  30  consists of a metal strip bent in U-form, in which at one end there are formed a pair of crimping claws  19 ,  20 , and at the other end a pair of laterally spaced lugs  21 . Lugs  21  receive the rectangular contact pins of the connecting plug and serve as an introduction aid therefor. The distance between the U-shaped shanks of the metal strip is chosen in such manner that the rectangular current conductor contact pins of the connector plug are engaged snugly and with force-closure, i.e. have contact. 
     The crimp connection pin  31  for the ground conductor is designed according to the preferred example represented in FIG. 2 as an L-shaped metal part, having a leg thereof formed from a U-shaped metal strip so that, as with the crimp connection pins  30 , there results a U-shaped metal strip  22  with a pair of crimping claws  23 ,  24 . The second leg, or base of the L-shaped crimp connection  31  is formed by two webs  25  extending from the U-shaped leg. The two webs  25  spring against one another and include receiving claws  26  for the round contact pin of the connector plug. The spacing of receiving claws  26  to one another is chosen in correspondence to the diameter of the round contact pin, i.e., the ground conductor. On one side of the receiving claws  26 , facing away from the crimping claws  23 ,  24 , there is formed in each case an obliquely outwardly directed lash  27  which facilitates introduction of the protective conductor contact pin. Because of the only slight contact length of the contact pin inside the receiving claws  26  of the parallel webs  25 , only a relatively slight plugging force is required. 
     In order to prevent the possibility that, for example, a connection plug may be inserted with too thick a protective conductor contact pin, the receiving claws  26  include cross webs  26 ′. Cross webs  26 ′ cooperate with complementary stops  29  (in the interior of the cover cap  28 ) to prevent overstretching of receiving claws  26 . 
     The “cross section form,” i.e., the form of the crimp connection pin  31  for the protective conductor contact pin also may be other than L-shaped; there is also thinkable a Z-form or the like, for example. 
     In FIG. 3, the crimp connection pins  30  and  31  are positioned in base body  1 . The two laterally lying crimp connection pins  30  lie in the insertion channels  11 , and  13  formed from the molded-on pins  8  and columns  9 ,  14 ,  15  and crimping connection pin  31  lies in the middle insertion channel  12 . The crimping connection pin  31  is supported by its two resilient webs  25  between the higher columns  14 ,  15  lying opposite the face wall. The receiving claws  26 , molded on the upright webs  25  of the L-shaped crimp connection pin  31 , lie opposite the passage opening  18  in the face wall  5 . 
     FIG.  4  and FIG. 5 show a cover cap  28  complementary to the base body  1 , which cap is so constructed that it closes over the incisions  2  for the crimp connection pins  30 ,  31 , stands upright on the raised edges  6 ,  7  and abuts the periphery of face wall  5 . In this way, the interior space of insert  50  is protected against the plastic injected into an injection mold to form a complete receptacle. As mentioned with the aid of FIG. 2, the cover cap  28  has on its inside two stops  29  complementary to the cross webs  26 ′ of the receiving claws  26  of the crimp connection pin  31 , which stops protect the receiving claws  26  against an overstretching. Stops  29  are connected, via a cross web  29 ′, to the ends of receiving claws  26  away from the face side of the cover cap  28 , wherewith a support against tilting is ensured for the receiving claws  26 , in the inserting of the connector plug. 
     According to the representation in FIG. 6, the cover cap  28  is emplaced or clipped on the base body  1 , so that now there is present a closed body/insert  50 . To the outside there stand out only the spired crimp claws  19 ,  20 , and  23 ,  24 , of the crimping connection pins  30 ,  31 , respectively. The representation in FIG. 6 shows the assemblage state in which the strands of a supply line are laid in and the crimping tool is applied. 
     FIG. 7 shows the body/insert  50  with a crimped-on supply line  51  in which, for reasons of perspicuity, the cover cap  28  is not shown in the drawing. The three strands  52 ,  53 ,  54  of this supply line are crimped according to their respective allocation with the crimp connection pins  30 ,  31 . According to the present invention, strands  52 ,  53 ,  54  of supply line  51  are crimped to connection pins  30 ,  31  with a one-piece crimping tool which “rolls up,” i.e., crimps with form and force closure, the strand connections  52 ,  53 ,  54  of the supply line  51 , that lie in one and the same plane with the crimp connection pins  30 ,  31  lying in the same plane, i.e., the working plane. 
     With the aid of FIG. 8 there is to be shown the end product “PLUG COUPLING.” The insert/body  50  joined with the supply line  51  is injection-molded from soft-elastic plastic material, so that there results a finished plug coupling  60 . This has on its quasi face side formed by the face wall  5 , the three through openings  17 ,  18  (described above in connection with FIG. 1) into which the complementary contact pins of an apparatus plug can be inserted, wherewith then the connection with the current supply mains can be established.