Abstract:
Described is an electrical plug connector with a cylindrical plug ( 20 ), a counterplug ( 1 ) which is complementary to plug ( 20 ), a bayonet ring ( 23 ) which is rotatable about the housing ( 3 ) of the counterplug ( 1 ) for locking the plug connector ( 20 ) into the counterplug, where the bayonet ring ( 2 ) can be pushed in the direction of plug insertion for the locking of the plug ( 20 ) on the housing ( 23 ) of the plug, until at least one locking device of the bayonet ring ( 2 ) has interlocked with the plug housing ( 23 ) and the bayonet ring ( 2 ) can be rotated about the counterplug housing ( 3 ) for the purpose of unlocking the plug connector.

Description:
FIELD OF THE INVENTION 
     The invention concerns an electrical plug connector, in particular for automotive applications with a cylindrical plug, a counterplug which is complementary thereto and a bayonet ring which is rotatable about the housing of the counterplug for the locking of the plug into the counterplug Such plug connectors are preferably located in the wall of a housing in order to link the electrical connectors of a device located within the housing with outside current conductors. For example, such plug connectors are used as gearbox pre-cabling. 
     BACKGROUND OF THE INVENTION 
     Especially in the area of motor vehicle gearboxes there occur, apart from relatively high operating temperatures, strong vibrations that may lead to the loosening of the plug connector. 
     In order to make the plug connector safe from becoming loosened, existing plug connectors have control systems which are intended to lock the plug into the counterplug. For example, such plugs have a bayonet ring as a locking device. Care must be taken during fitting to ensure that the locking device really is locked into place. It can however happen in practice that during the process of plug insertion such a rotation movement of the bayonet ring is undesirable. In this way, the plugs can be arranged in difficult to reach narrow areas of a gearbox housing where whilst the rotating movement is possible it is time-consuming because the bayonet ring is, for example, difficult to grip. 
     The task of the invention is that of creating an electrical plug which is simple to assemble and dismantle, even in areas, which are accessible with difficulty. 
     This task is accomplished by means of the characteristics of patent claim  1 . 
     SUMMARY OF THE INVENTION 
     The electrical plug connector according to the invention comprises a cylindrical plug, a counterplug which is complementary thereto and a bayonet ring which can be rotated about the counterplug housing for the purpose of locking the plug into the counterplug. In order to lock off the plug connector, the bayonet ring can be pushed on the housing of the plug in the direction of insertion, until at least one locking device of the bayonet ring has interlocked with the plug housing. Further, in order to unlock the plug connector, the bayonet ring can be rotatable about the counterplug housing. 
     The combined action, according to the invention of the bayonet ring and the plug brings it about that the bayonet ring can simply be pushed in the direction of plug insertion. This means that in order to lock the plug into the counterplug, the bayonet ring is not rotated but pushed along the axis of the plug housing on the latter. The plug connector is loosened by means of rotating the bayonet ring. 
     The invention offers the advantage that the plugs can be locked rapidly and reliably. The fitter only needs to press the counterplug on the plug, The fitting of such plug connectors takes place more frequently than their dismantling, since these plug connectors are only loosened when, for example, the gearboxes are serviced. In this way, in vehicle mass production, the fitting of such plug connectors is made more rapid without losing the advantages of a bayonet closure that is important in moving belt production. In contrast, a vehicle mechanic can spend the necessary time in carrying out repair work on a vehicle, making the time needed for the rotation of the bayonet ring in order to loosen the plug connector non-critical. 
     Further advantageous developments of the invention are characterised in the subsidiary Claims. 
     An advantageous embodiment of the invention is that the locking device comprises at least one spring tongue with an inward-directed peg moulded onto the bayonet ring and running in the direction of plug insertion and that the circumference of the plug housing has at least one sliding channel which is suitable for receiving the peg. The start area of the sliding channel runs substantially at an angle to the direction of plug insertion. The terminal area of the sliding channel runs substantially parallel to the direction of plug insertion where the terminal area has at least one locking lug which can be negotiated by the peg, where both areas run into the front face of the plug housing. These further developments offer the advantage that the peg of the spring tongue and the locking lug of the terminal area achieve the locking of the plug connector. The sliding channel which runs parallel to the direction of plug insertion makes it possible for the bayonet ring to be pushed in the direction of plug insertion. On the bayonet ring being rotated, the start area of the sliding channel which runs at an angle forms a step-down, so that the dismantling of the plug connector is made easier. 
     A further advantageous embodiment of the invention is that the bayonet ring has at least one outward-pointing pin. Apart from this, the plug housing may have at least one lever arm, which can be rotated vertically to the direction of plug insertion in order to grip the pin. On actuating the lever arm, the required force of insertion is reduced. 
     A further advantageous embodiment of the invention is the fact that the bayonet ring has two diametrically opposite pins. The plug housing may have two diametrically opposite L-shaped lever arms that are connected by essentially semicylindrical C-straps. When the C-strap is actuated, both the L-shaped lever arms grip the outward-pointing pins. In a locked state, the C-hoop and its two L-shaped lever arms form an additional rotation lock. 
     Yet another advantageous embodiment of the invention consists in the fact that about the plug housing between a stop element and the direction of plug insertion a collar is arranged which can be pushed forwards or backwards. This makes it possible for the collar to shield the plug housing from possible soiling. 
     A further advantageous embodiment of the invention is that a pressure spring pushes against a first stop of the collar and against a second stop of a circlip so that in the event of incomplete insertion of the bayonet ring the latter will be pushed back through the front face of the collar. This offers the advantage that the fitter will immediately see when the bayonet ring is in the locking position so that if this locking position is not reached, the bayonet ring will automatically be pushed back through the collar. 
     A further advantageous embodiment of the invention is that following the complete insertion of the bayonet ring, the collar rests on the spring tongues. In this way, the collar acts as a secondary lock, since the spring tongues including pegs cannot come out of their locked position without hitting against the collar. 
     An embodiment example of the invention is represented in the schematic diagram and will be described in greater detail below, as further particularities and advantages of the invention obtained. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The following is shown by the figures: 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1 a perspective view of a counterplug according to the invention, including bayonet ring; 
     FIG. 2 an exploded view of the plug according to the invention; 
     FIGS. 3 a - 3   d , a perspective view of the plug according to the invention with the plug from FIG.  2  and the counterplug from FIG. 1 in various positions; 
     FIG. 4 is a schematic section along line A from FIG. 3 a;    
     FIGS. 5 a - 5   d  a part-enlargement of area E of FIG. 4 in various positions. 
     FIG. 1 shows an exploded view of a counterplug  1  with a bayonet ring  2  and a counterplug housing  3 . The cylinder-shaped bayonet ring  2  has on its outer circumference two outward-pointing pins  4  and three spring tongues  5 ,  6  and  7  each with an inward-pointing peg  8 . The counterplug housing  3  has, along the direction of plug insertion, electrical contact chambers  9  which can be locked with the coding  11  by means of a cross slide  10 . The counterplug housing  3  which is also cylindrical has on its circumference behind the cross slide  11  a profiled gasket ring  12  resting on a first guide rail  13  which runs over the entire circumference of the counterplug housing  3 . Together with a second guide rail  14  which also runs over the entire circumference of the counterplug housing, it encloses a rotation guide channel  15  to receive the bayonet ring  2 . 
     FIG. 2 shows an exploded view of a plug  20  according to the invention which fits into the counterplug  1 . From left to right are shown an insert  21  with a cross slide  22  which also has a coding  29 , a plug housing  23  with a swivelable strap  24 , a circlip  25  with four outward-pointing second stop elements  26  and a substantively cylindrical collar  27 . The insert  21  also chambers  30  which also run in the direction of plug insertion for the reception of electrical contacts, two outward-pointing diametrically opposite locking arms  31  on its circumference and a guide channel  32  also on its circumference, which runs in the direction of plug insertion. The insert  21  can be arranged in the front opening  33  of the plug housing  23 . 
     The substantively cylindrical plug housing  23  has three sliding channels  34 , each of whose start area  35  runs at an angle to the direction of plug insertion and whose terminal area  36  runs parallel to the direction of plug insertion. Both areas  35  and  36  run into the front face  37 . A locking lug  41  which is enclosed by a ramp  39  and a plane  40  which runs parallel and vertically to the direction of insertion, is moulded on in the terminal area  36  of the sliding channel  34  in the vicinity of the front face  37  (cf FIG.  4 /FIG.  5 ). On the circumference of the plug housing  23  there are two diametrically opposite, outward-pointing studs  45  which are located at approximately the same distance from the front face  37  and the rear face  46 . The C-shaped substantively semicylindrical strap  24  links two substantively L-shaped lever arms  47  and  48  whose one end  49  are arranged to swivel about the stud  45 . On the level of the stud  45  along the circumference of the plug housing  23  is a moulded-on outward-pointing rail  50 . From this rail  50  run parallel to the direction of insertion two side walls  51  and  52 , which terminate in the vicinity of the rear face  45  and enclose a spring chamber  55 . 
     Altogether there are provided, arranged on the circumference of the plug housing  23  and offset by 90° four such spring chambers  55  including sidewalls  51  and  52 . A channel  56  to receive the circlip  25  is incorporated in the rear face  46 . 
     The front part  60  of the substantively cylindrical collar  27  has a bigger radius than in its rear Part  61 . Diametrically opposite one another and running in the direction of plug insertion and into the front area are provided two recesses  62  for the strap  24 . Inside the rear part  61  are located to fit into the spring chambers  55 , a first stop  63  and parallel to the direction of plug insertion two guide walls  54  whose distance apart is so chosen that the side wall  51  and  52  can slide in between. Further, on the level of the first stop  63  an inward-pointing partly interrupted sliding shoulder  65  is moulded on, whose inside radius is so chosen that the sliding shoulder can be led to the shell surface  53  of the plug housing  23  between the side walls  51  and  52 . 
     To build up the plug connector, the chambers  9  and  30  are first fitted with electrical contacts and then locked by the corresponding cross-slides  10  or  22 . In the case of the counterplug  1 , the next step is that of drawing the bayonet ring over the housing  3 , so that the shoulders  17  of the bayonet ring  2  which are not shown in FIG. 1 reach the guide channel  15 . In the case of the plug  20 , the insert  21  is introduced into the opening  33  of the plug housing  23  until the locking arms  31  are locked in there. As the next step, the collar  27  is pushed on the plug housing  23  in such a way that the stop  63  arrives between the corresponding sidewalls  51  and  52  until it strikes against the rail  50 . Thereafter, each of the four spring chambers  55  is fitted with a pressure spring, which is not shown. The circlip  25  is then introduced into the channel  56 , so that the second stops  26  are arranged between the side walls  51  and  52 , reach the pressure spring  66  and close the spring chamber  55 . 
     Following the assembly of the plug and the counterplug, they can be inserted into one another as explained below. 
     FIGS. 3 a  to  3   d  show in perspective a plug connector in various positions with the counterplug  1  from FIG.  1  and the plug  20  from FIG.  2 . 
     FIG. 3 a  shows the plug connector according to the invention at the initial stage of the insertion process. When the lever is swivelled downwards, the free end  44  of the lever  47  reaches the pin  4 . As will also be explained below, the spring tongues  5 - 7  are lifted so that their free ends  19  reach the front face  70  of the collar. If the strap  24  is swivelled further towards the plug connector, the free end  44  of the lever  47  grips the pin  4  so that the bayonet ring  2  is pushed over the plug housing  23  and the outward-protruding spring tongues  5 ,  6  and  7  engage the collar  27 . As will be explained more fully below, during this process the pressure spring  66  will be compressed between the first stop element  63  and the second stop element  25 , because the distance between these stops  26  and  63  is reduced by the downward swiveling of the strap  24 , as can be seen from the dotted-line representation in FIG. 3 b . If the pegs  4  reach the bend  43  of the lever  47 , then the spring tongues  5 ,  6  and  7  release the collar  27  by locking the latter inwards. This position is shown in FIG. 3 b . Since the pressure spring which is not shown here is under compression, the collar  27  is pushed in the arrow direction D until the first stop  63  reaches the rail  50  as can be seen in FIG. 3 c . In this way, the plug connector is in the locked position. 
     To open the plug connector, the strap  24  must first be swivelled so that a right-hand thread in the arrow direction C (cf FIG. 3 d ) can rotate the bayonet ring  2 . In the process, the pegs  8  in the starting area  35  of the sliding channel  34  slide to the front face  37 . The housings  3  and  23  move away from one another. The plug connector is loosened as soon as the pegs  8  have left the sliding channels  35 . 
     FIG. 4 shows a section along the line A of the plug connector according to the invention from FIG. 3 a , where the bayonet ring  2  has been pushed some way on the plug housing  23 , but the spring tongues  5  to  7  have not yet been lifted. Starting from the left, it is possible to see outside the bayonet ring  2  with the moulded-on spring tongues  5 , on which the substantially cylindrical peg  8  is moulded-on via its angled edge  16 . The shoulder  17  of the bayonet ring  2  is in the guide channel  15  of the counterplug housing  3 , so that the bayonet ring  2  is placed to be able to rotate about the counterplug housing  3 . Behind the first guide rail  13  is the profiled gasket ring  12 . 
     Outside on the right-hand side is shown the bayonet ring  27  with the front part  60  and the rear part  61 . The collar  27  is located around the plug housing  23 , so as to be able to rotate owing to the first stop  63  and the sliding shoulder  65  of the collar  27  which slide on the shell surface  53  of the plug housing  23 , The rear part  61  of the collar  27 , the first stop  63 , the second stop  26  and the shell surface  53  enclose the spring chamber  55 . FIG. 4 shows clearly that the insert  31  in the plug housing  23  is arranged against cable admission shafts  28  of the plug housing  23 . In contrast with FIG. 3 a , the section A—A of FIG. 4 passes through the centre of the strap  24  as can be seen in the lower part of FIG.  4 . Starting from the front face  37  of the plug  20  can be seen the locking lug which is moulded on the terminal area  36  of the sliding channel  34 . With the pressure spring  66  slack, this area (the locking lug  41  and the sliding channel  34 ) are overlapped by the front part of the collar  27 . 
     Below, FIGS  5   a  to  5   d  show the combined effect of the spring tongues  5  to  7  and the locking lugs  41  and the front face  70 . 
     FIGS. 5 a  to  5   d  show a schematic part-enlargement of the area E from FIG. 4 at various stages of the plug insertion process. For simplicity, only the spring tongue  5  with the formed-on peg  8  of the bayonet ring is shown. On the right-hand side of FIGS. 5 can be  15  seen a part of the collar  27  in the upper part and underneath a part of the plug housing  23 . At the rear end of the plug housing  23  is shown a part of the circlip  25  with the second stop  26 . In addition to FIG. 4, FIG. 5 shows the pressure spring  66  between the first stop  63  and the second stop  25 . As can be seen in the Figures, the section passes through the locking lug  41  which is enclosed by an angled or slightly rounded ramp  20   38 , a plane  39  which is parallel to the direction of plug insertion and a vertical plane  40 . 
     FIGS. 3 and 5 explain the manner of operation of the process of plug insertion. The fitter introduces the counterplug  1  from FIG. 1 into the plug  20  from FIG. 2, so that the  25  codings  11  and  29  grip correctly. During this process, the bayonet ring  2  reaches the plug housing  23  as seen in FIGS. 4 ad  5   a . The pressure spring is still slack, since the distance between the first stop  63  and the second stop  26  is at its maximum. 
     If the bayonet ring is pushed further on the plug housing, with or without the strap  24  as shown in FIG. 3 a , the spring tongue  5  with the moulded-on peg  8  of the bayonet ring  2  approaches the locking lug  41 . 
     By further pushing of the bayonet ring  2 , the angled edge  16  of the peg  6  reaches the ramp  38  so that the spring tongue  5  is lifted and projects above the shell surface of the bayonet ring  2 . The free end  19  of the spring tongue  5  reaches against the front face  70  of the collar  27  as shown in FIGS. 3 a  and  5   d . If the bayonet ring  2  is pushed further by spring arm  5 , the collar  27  is pushed back in the arrow direction H, whereby the distance between the stop  63  and the second stop  26  is reduced. During this process, the first stop  63  moves away from the shoulder  50 . 
     If the bayonet ring  2  is pushed further on the plug housing  23  whether by hand or via the strap  24 , then the locking lug  41  is negotiated by the peg  8  so that the vertical plane  40  rests against the vertical plane  18  of the peg  8 . The spring tongue  5  releases the collar  27 , whereby the distance between the first stop  63  and the second stop  26  reaches its minimum, that is to say, the pressure spring  66  has maximum force at this stage (FIG. 3 b  and FIG. 5 c ). When the collar  27  is released, the spring  66  which is under compression can release its energy and push the collar  27  back in the arrow direction D, as shown in FIGS. 3 b  and  5   c . The first stop  63  again approaches the shoulder  50 , until they are again in contact. The front area of the collar  27  overlaps the spring tongue  5 , so that the latter cannot jump out of its locked position (as shown in FIG. 3 c  and FIG. 5 d ). The position of the collar  27  from FIG. 5 d  corresponds to the position in  20 FIG. 5 a , where the counterplug  1  has now been fully inserted into the plug  20  and the spring tongues  5 - 7  are locked in. Neither can the spring tongues  5 - 7  come out of their locked position owing to the front area  60  of the collar  27 , nor is a rotational movement of the collar  27  possible, since the strap  24  effectively encloses the pins  4 . In this way, a plug connector is obtained which is secure and unusually difficult to loosen. 
     It should be noted that when the fitter releases either the bayonet ring  2  or the lever  24  prematurely, that is to say, for example, in the position shown in FIGS. 3 a  and  5   b , the collar  27  is pushed in arrow direction D by the power of the compressed spring  66  until the first stop  63  reaches the rail  50 . In the process, the counterplug  1  including bayonet ring  2  is moved away from the plug housing  23 . If a strap  24  is present, then this is also correspondingly swivelled, loosening the plug connector. If the plug connector is not correctly locked, the combined action of the collar, the first stop, the second stop and the spring tongue enable a direct report of the fact to the fitter. 
     The previously described characteristics of the embodiment examples can be combined with one another at will.