Jack plug
BACKGROUND OF THE INVENTION 
     a) Field of the Invention 
     The invention is directed to a jack plug with a plug housing formed by two shells and a cable bushing which can be screwed onto a thread provided at the plug housing and penetrated by the cable to be connected. 
     b) Description of the Related Art 
     A jack plug of this constructional type is known (U.S. Pat. Nos. 5,180,317 and 5,261,839). In this previously known construction, a cylindrical groove is formed on each of the two shells forming the connector housing. When the shells are assembled, these two cylindrical grooves form a cylindrical member having an external thread on which a cable bushing can be screwed. One shell has, at one end, pins and bore holes whose axes extend at right angles to the dividing plane of the housing and which engage in one another when the shells are assembled so as to position the latter. Further, a longitudinal contact lug with crimpable plates is formed on the inside of the shell having the contact shafts. These crimpable plates serve to produce the ground connection of the connected cable. This construction is not advisable since the two shells forming the plug housing are only inadequately secured due to the fact that the above-mentioned bore holes and pins used for positioning can only secure the two shells with respect to possible displacement in the dividing plane of the housing, but can not absorb forces acting at right angles to the dividing plane of the housing. Also, a special tool is required for connecting the ground conductor of the cable. 
     OBJECT AND SUMMARY OF THE INVENTION 
     The primary object of the present invention is to provide an improved construction of a jack plug of the type mentioned above and further to design it so as to facilitate assembly. This object is met according to the invention in that the plug has a cylindrical neck which is substantially closed circumferentially and has a thread which is provided at the end of one shell. The other shell having a pin-like projection at its corresponding end side. This projection is received in a correspondingly constructed slot provided in the neck having the thread. The locking members which engage with one another in a positive engagement and secure the shells in their dividing plane and at an angle thereto are provided at the other end sides of the two shells. The cable bushing screwed onto the thread engages in a positive locking manner over the slot and the projection received in the latter, so that the shells forming the plug housing are secured relative to one another by the locking members on one side and by the positive-locking projection on the other side. 
    
    
     In order to illustrate the invention, an embodiment example of a jack plug will be explained more fully with reference to the drawings, but without thereby limiting the invention to the embodiment example illustrated here. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In the drawings: 
     FIG. 1 shows a longitudinal section through the jack plug according to the invention; 
     FIG. 2 is a plan view of one shell; 
     FIG. 3 is a top view thereof; 
     FIG. 4 shows a side view of this shell (as seen in the direction of arrow A in FIG. 2); 
     FIG. 5 shows a second side view of the shell according to FIG. 2 (as seen in the direction of arrow B in FIG. 2); 
     FIG. 6 shows a plan view of the second shell, partially cut away; 
     FIG. 7 is a bottom view thereof; 
     FIG. 8 is a top view thereof; 
     FIG. 9 shows a plan view of the clamping collet; 
     FIG. 10 shows a top view thereof; 
     FIG. 11 shows a side view thereof (as seen in the direction of arrow C in FIG. 9); and 
     FIG. 12 shows a side view of the cable bushing in partial section. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The jack plug according to FIG. 1, which is constructed as an angle connector, has a plug housing 1 formed by two shells 2 and 20. One shell 2 which is advisably produced from metallic material by diecasting technique has a groove-shaped portion 3, the outer contact shaft 4 being formed on integral therewith at one end. The contact of this angle plug is constructed as is conventional: the contact bulb or tip 5 is connected with a contact pin 6 which ends in a connection piece 7 inside the plug housing, the central conductor of the cable to be connected being secured at this connection piece 7. Insulating inserts 8 and 9 hold the contact tip 5 and its contact pin 6 in the provided position. A hook-like abutment 10 is formed integral with the front side of the shell 2 adjoining the outer contact shaft 4. The other end side of the shell 2 has a cylindrical neck 11 with an external thread 12. A slot 13 is cut out of this thread 12, or out of the neck 11 carrying this thread, proceeding from the housing side 14 of the cylindrical neck 11 (FIG. 3). The inner wall 15 of the shell 2 is delimited cylindrically at the front adjacent to the insulating insert 9 by projecting stops 16. The axis of the outer contact shaft 4 is situated at right angles to the dividing plane E (FIG. 2) of the plug housing 1. 
     The second shell 20 of the plug housing 1 shown in several views in FIGS. 6, 7 and 8 is advisably formed of plastic. It has a groove-like main portion 17 which is closed on one side by a semispherical shell 18 with a cut out portion 19. A pin-like projection 22 whose thickness s is somewhat greater than the wall thickness w of the cylindrical neck 11 with the external thread 12 is formed integral with the other end side 21 which is likewise closed. The longitudinal side cheeks 23 of the pin-like projection 22 are beveled somewhat and converge toward the bottom in a wedge-shaped manner. 
     Another structural component part of the jack plug is the clamping collet 30 which is manufactured from insulating plastic. This clamping collet 30 has a longitudinal slot 29. At the end of the clamping collet 30 to be received by the cable bushing 31, this clamping collet 30 is beveled conically at the outside and divided into springing plates 27 by a plurality of axially parallel notches 28 proceeding from the end mentioned above. These plates 27 can be provided with ribbing 26 internally. The portion of the clamping collet 30 received by the plug housing is stepped (FIGS. 9 and 10), the axially parallel longitudinal slot 29 extending in the shorter part of the clamping collet 30. The clamping collet 30 is symmetrically formed with respect to an imaginary longitudinal center plane containing its longitudinal axis and the longitudinal slot 29. The stepped portion 25 of the clamping collet 30 extends along roughly one third of its length. An imaginary plane containing the stepped portion 25 extends approximately through the longitudinal center axis of the clamping collet 30. A slot 24 is cut out of the wall of the clamping collet 30 located opposite the longitudinal slot 29. This slot 24 is advisably closed circumferentially as can be seen from FIG. 10. The inner end side 32 of the clamping collet 30 contacts the shell 2 of the plug housing 1 receiving it at stops 16. 
     Finally, the cable bushing 31 has a screwing part 33 formed of resistant sturdy material and an elastic part 35. An internal annular shoulder 34 cooperates with the beveled end of the clamping collet 30. 
     The parts described above are assembled as shown in the longitudinal section in FIG. 1. To assemble, the cable to be connected (not shown) is first inserted through the cable bushing 31 into the clamping collet 30 via the longitudinal slot 29. This insertion is facilitated by the rounded edges 36 of the stepped portion 25. After removing the insulation from the end region of the conductor, the cable with this conductor is inserted through the cylindrical neck 11 by this conductor portion, the exposed shielded conductor having been first inserted through the slot 24 and bent back. The clamping collet 30 with the inserted cable is now located in the shell 2 and the center conductor of the cable to be connected is secured to the connection piece 7, the clamping collet 30 contacting the stops 16 by its inner end side 32. The cut out portion 19 of the shell 20 is then hooked onto the hook-like abutment 10 and the shell 20 is swiveled relative to the first shell 2 so that the projection 22 comes to rest in the slot 13 of the cylindrical neck 11. In so doing, the projection 22 engages in the longitudinal slot 29 of the clamping collet 30 and the side cheeks of the projection 22 which converge at the bottom facilitates this insertion into this longitudinal slot 29. The cable bushing 31 is then screwed onto the thread 11, the screwing part 33 engaging over the projection 22 situated within the slot 13 so that the two shells 2 and 20 are secured relative to one another. At the same time, the annular shoulder 34 runs along the inside of the cable bushing 31 at the beveled end of the clamping collet 30 projecting opposite the thread 12 and cylindrical neck 11 and presses the springing plates 27 against the surface of the cable (not shown), thus forming the required pull protection. 
     Modifications are possible within the scope of the subject invention. If the neck 11 with the thread 12 is formed integral with the shell having the contact shafts and contact pins in the described embodiment example, it is conceivable in principle to form this cylindrical neck 11 with thread 12 so as to be integral with the attachable shell 20 and to provide the projection 22 at the shell 2 instead, so that the arrangement of the structural component parts serving to lock the two shells is reversed with respect to the shells. A positive-locking engagement other than the hook-like abutment 10 provided here is also possible, e.g., by means of a projecting or protruding edge at the rim of the semispherical shell 18 which would be received by a groove provided in shell 2. In all cases, the positive-locking connection is designed in such a way that the two shells 2 and 20 are secured relative to one another not only in their dividing plane, but also relative to the influence of forces acting at an angle to the dividing plane E. 
     While the foregoing description and drawings represent the preferred embodiments of the present invention, it will be obvious to those skilled in the art that various changes and modifications may be made therein without departing from the true spirit and scope of the present invention. 
     
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Reference Numbers:                                                        
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1     plug housing       30    clamping collet                            
2     first shell        31    cable bushing                              
3     groove-shaped portion                                               
                         32    inner end side                             
4     outer contact shaft                                                 
                         33    screwing part                              
5     contact tip        34    shoulder                                   
6     contact pin        35    elastic part                               
7     connection piece   36    rounded edge                               
8     insulating insert                                                   
9     insulating insert                                                   
10    hook-shaped abutment                                                
11    cylindrical neck                                                    
12    thread                                                              
13    slot                                                                
14    housing side                                                        
15    inner wall                                                          
16    stop                                                                
17    groove-like main portion                                            
18    semispherical shell                                                 
19    cut out portion                                                     
20    second shell                                                        
21    end side                                                            
22    pin-like projection                                                 
23    side cheeks                                                         
24    slot                                                                
25    stepped portion                                                     
26    ribbing                                                             
27    plate                                                               
28    notch                                                               
29    longitudinal slot                                                   
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