Abstract:
The invention relates to a current-carrying lead, in particular a connecting lead and a heating tape ( 5 ), for a plug connector, which current-carrying lead has at least two strands ( 49, 50 ) that are partly surrounded by electrical insulation ( 47 ). The current-carrying lead is provided with at least one reservoir ( 53 ) for an electrically insulating medium ( 54 ). The reservoir ( 53 ) is closed by least one plunger ( 55 ), by means of which the sealing medium ( 54 ) can be forced through at least one outlet nozzle ( 57 ) into at least one sealing chamber ( 58  to  60 ). The plug connector having a current-carrying lead ( 3, 5 ) has a sealing device ( 36 ) having a sealing body ( 66 ). Said sealing body has an elastically deformable sealing part ( 71 ) that can be elastically deformed by means of a wedge-type slider ( 77 ). The wedge-type slider ( 77 ) has a conical face ( 82 ) that interacts with a conical face ( 76 ) of the sealing part ( 71 ). The wedge-type slider ( 77 ), which is preloaded axially by a compression spring element ( 84 ), is guided in a holding part ( 78 ) axially securing the sealing body ( 76 ). The lead ( 3, 5 ) is supported in a strain relief device ( 44 ) by a multi-point support. Said strain relief device has pressure pieces ( 91  to  94 ) respectively located opposite one another in pairs, of which the one pressure piece pair ( 91, 92 ) is located at a right angle to the other pressure piece pair ( 93, 94 ). The pressure pieces of the one pressure piece pair ( 93, 94 ) are forcibly guided by the pressure pieces of the other pressure piece pair ( 91, 92 ).

Description:
BACKGROUND OF THE INVENTION 
     The invention concerns a current-carrying lead, in particular connecting lead and heating tape, for a plug connector, comprising at least two litz wires that are partially surrounded by an electrical insulation. The invention concerns also a plug connector comprising such a current-carrying lead and comprising at least one sealing device provided for the lead that comprises at least one sealing member that comprises at least one elastically deformable sealing part that, by introducing a force that is acting in the longitudinal direction of the lead, is elastically deformable transversely to this longitudinal direction against the lead, wherein the sealing part is deformable elastically by at least one wedge slider that is provided with a conical surface that interacts with a conical surface of the sealing part. The invention also relates to a plug connector in which the lead is supported by a multi-point support in a strain relief device that has four pressure members which are positioned opposite each other in pairs, respectively. 
     Current-carrying leads in the form of connecting leads and heating tapes are known which are connected to each other by means of the plug connector. By means of the heating tapes, pipes, containers, channels and the like are maintained at defined temperatures. For example, the heating tapes are attached to conveying lines in order to keep the medium flowing within the conveying lines at a defined temperature so that it is flowable or can stream. Often, at the end of the heating tape moisture will deposit and thereby change the leakage current resistance of the heating tape. In particular in moist or wet conditions of use, the moisture penetrates as a result of capillary action or moisture is generated by a pumping effect which is caused by cooling or heating. Between the litz wires of the heating tape, an initially small, over the course of time greater, moisture collection is produced on which electrical leakage currents can flow. Because of this, there is the risk that the heating tape will suffer from scorch marks between the two litz wires. Progressively, the leakage current resistance can even drop so far that short circuiting may be produced. 
     Moreover, the contacting action of heating tape and connecting lead must be protected from environmental effects in order to avoid short-circuiting by moisture penetration between the potentials of the litz wires. 
     For this purpose, glands with matched nut are known through which the electrical lead is projecting. The gland is elastically deformed in radial inward direction so that it contacts seal-tightly the heating tape. This deformation of the gland causes flexing, i.e., a deformation in circumferential direction. This has the result that the sealing effect is reduced because due to the flexing movement passageways inwardly into the plug connector are formed. Accordingly, through the gland moisture from the exterior can penetrate and can cause the afore described problems within the plug connector. 
     The invention has the object to configure the current-carrying lead of the aforementioned kind and the plug connector of the aforementioned kind in such a way that, while providing a simple configuration and inexpensive assembly, it is ensured that a leakage current generation due to moisture in the plug connector is avoided. 
     SUMMARY OF THE INVENTION 
     This object is solved for the current-carrying lead of the aforementioned kind in accordance with the invention in that the electrical insulation comprises at least one reservoir for an electrically insulating medium that is closed off by at least one plunger that forces the sealing medium through at least one outlet nozzle into at least one sealing space. The invention is solved for the plug connector of the aforementioned kind in accordance with the invention in that the wedge slider is guided in a securing part that axially secures the sealing body and in that the wedge slider is pre-tensioned axially by at least one pressure spring element that is actuatable by at least one pressure member. The invention is further solved in connection with the plug connector comprising a strain relief device in that the first oppositely positioned paired pressure members are positioned angularly to the two other oppositely positioned pressure members and in that two oppositely positioned pressure members are forcibly guided by the two other oppositely positioned pressure members. 
     The current-carrying lead according to the invention is characterized in that a reservoir containing an electrical insulating medium is integrated in its electrical insulation. It is advantageously an electrically insulating gel with which the collection of moisture on the heating tape end or connecting lead end is avoided. The reservoir is closed off by a plunger so that the sealing medium cannot escape to the exterior. When the plunger is pushed into the reservoir, the sealing medium contained therein is forced through the outlet nozzle into the sealing space. Here, the sealing medium distributes within the critical space and prevents thus that moisture can collect therein between the litz wires. The volume of the reservoir is matched to the volume of the sealing space in such a way that the sealing medium completely fills the sealing space in any case. The sealing space is located in front of the insulated end of the heating tape or the connecting lead. The litz wires extend through the sealing space and are, by the way, surrounded by the electrical insulation. 
     The electrical insulation is advantageously an insulation body that surrounds insulatingly and with mechanical protecting action the litz wires, from which insulation has been stripped across a portion of their length, and that is attached to the heating tape or to the connecting lead. 
     Advantageously, the plunger is secured against displacement in at least one position on the insulation. The plunger is secured at least in the pushed-in position so that it is ensured that the sealing medium cannot flow out of the sealing space into the reservoir. 
     It is however also possible that the plunger is positionally secured in its initial position when the reservoir is filled. Then it is ensured that the plunger secures the reservoir outwardly and cannot be lost. 
     Advantageously, the plunger is displaced only when plugging in the plug connector so that only then the sealing medium is displaced from the reservoir into the sealing space. 
     The plug connector according to the invention comprises the sealing device which reliably protects the contacting action of heating tape and connecting lead from environmental effects. The sealing device comprises the sealing body which comprises the elastically deformable sealing part. By introducing a force acting in longitudinal direction of the lead, it is elastically deformed transversely to this longitudinal direction so that it is contacting seal-tightly the outer side of the lead. Due to this elastic deformation, no flexing action occurs so that no passageways for moisture and the like can form. The sealing part is elastically deformed by at least one wedge slider. With it, the force that is acting in the longitudinal direction of the lead can be deflected very easily into the force which is transversely oriented thereto in order to apply seal-tightly the sealing part against the electrical lead. The sealing part is provided with a conical surface which interacts with a conical surface of the wedge slider. In order to deform the sealing part reliably by means of the wedge slider, the wedge slider is guided within a securing part. By means of the securing part, the sealing body is axially secured so that the latter remains in its position when its sealing part is elastically deformed. The wedge slider is axially pretensioned by means of the at least one pressure spring element so that the sealing function is ensured across a great temperature range. Since at corresponding temperatures the material property and the dimensions of the parts will change, the pre-tensioned wedge slider ensures that the sealing part is always seal-tightly resting on the electrical lead. The pressure spring element is actuated by the at least one pressure member. The pressure spring element is thus supported on the wedge slider as well as on the pressure member that effects the pretension acting on the wedge slider. 
     The sealing body is advantageously secured in the connector member of the plug connector against transverse sliding. In this way, by means of the transverse sliding securing action and the securing part, the sealing body is properly positionally secured upon elastic deformation of the sealing part as well as in the mounted position. 
     The pressure member is advantageously slidably guided within the securing part. 
     The pressure member is advantageously arranged such that it is actuated upon insertion of a plug component group. 
     The actuating element is advantageously a component of such a plug component group of the plug connector. 
     In the plug connector, advantageously a strain relief device for the lead is provided downstream of the sealing device. 
     In an advantageous embodiment, the securing part comprises an annular wall that is resting against an inner wall of a receiving space of a connector member of the plug connector. 
     In a preferred embodiment, the wedge member of the wedge slider is arranged between the securing part and the sealing part. In this way, the sealing part is forced securely against the lead to be sealed. 
     Preferably, the wedge member of the wedge slider has a straight outer side in axial section with which the wedge member is resting against an appropriate inner surface of the securing part. In this way, it is prevented that the securing part is deformed in radial direction inwardly. 
     The pressure spring element engages advantageously an end face recess of the wedge slider. 
     The plug connector according to the invention comprises at least one strain relief device by means of which a multi-point support action of the lead is enabled. The strain relief device is arranged such in the plug connector that possibly occurring tension forces are kept away from the contacting action and the downstream sealing device. The multi-point centering action has the result that the electrical lead, which can be a heating tape or a connecting lead, is centered. When downstream of the strain relief device a sealing device for the strain-relieved electrical lead is provided, then an optimal sealing action is ensured as a result of the centering action. The pressure members of the strain relief device are arranged in pairs opposite each other wherein the first oppositely positioned paired pressure members are positioned angularly to the two other oppositely positioned pressure members. Two oppositely positioned pressure members are forcibly guided by the two other oppositely positioned pressure members. In this way, by the movement of two oppositely positioned pressure members, all pressure members are moved in the direction toward or away from the electrical lead. In this way, it is possible to clamp the electrical lead very simply between the pressure members for strain relief or to release the electrical lead again. Due to the forced guiding action, an automatic centering action of the lead is realized so that the lead can be optimally sealed. 
     An advantageous forced guiding action results when the forcibly guided pressure members engage, by means of cams, guides of the other two oppositely positioned pressure members. With such a form fit action between the pressure members a reliable uniform adjustment of all pressure members is achieved. 
     In an advantageous embodiment, the guides of the other pressure members are provided at lateral surfaces of these pressure members and extend oppositely slanted relative to each other. In this way, it is ensured in a simple way that the pressure members are moved opposite to each other outwardly or inwardly in the direction toward the lead. 
     In order for the lead to be arranged reliably between the pressure members, it is advantageous to provide two pressure springs between two oppositely positioned pressure members. They load these two pressure members in such a way that they move away from the lead. By means of the forced guiding action, the two other pressure members are also moved correspondingly. By means of the pressure springs, the pressure members are thus moved apart from each other. 
     The pressure springs are seated advantageously on link members which link the two oppositely positioned pressure members with each other. 
     In an advantageous embodiment, the oppositely positioned pressure members are perpendicularly slidable relative to the other two oppositely positioned pressure members. 
     Further features of the invention result from the further claims, the description, and the drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be explained in more detail with the aid of some embodiments illustrated in the drawings. It is shown in: 
         FIG. 1  in section a plug connector according to the invention with two connector members prior to plugging in; 
         FIG. 2  the plug connector according to  FIG. 1  with plugged-in connector members; 
         FIGS. 3  to  5  in section, respectively, various mounting steps upon assembly of one of the connector members; 
         FIGS. 6 and 7  in section, respectively, individual method step upon assembly of the other connector member; 
         FIG. 8  in an enlarged illustration the connecting area of a heating tape that is to be connected with one of the connector members, before attachment on this connector member, still without actuation of the plunger; 
         FIG. 9  the heating tape after attachment to the connector member with suppressed plunger; 
         FIG. 10  in section and in enlarged illustration a sealing device for sealing a heating tape or a connecting lead within one of the connector members of the plug connector according to the invention in a first position; 
         FIG. 11  the sealing device according to  FIG. 10  in a second position; 
         FIGS. 12 and 13  in illustrations corresponding to  FIGS. 10 and 11  a second embodiment of the sealing device; 
         FIG. 14  in enlarged and exploded illustration a strain relief device of the plug connector according to the invention; 
         FIG. 15  in an enlarged illustration the strain relief device according to  FIG. 14  in a first position; 
         FIG. 16  the strain relief device according to  FIG. 14  in a second position. 
     
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
     The plug connector serves to electrically connect a connecting lead with a heating lead. The released heat of the heating lead keeps pipes or surfaces at the constant desired temperature and compensates partially differences in the ambient temperature. 
     The plug connector has two connector members  1 ,  2  which are shown in  FIG. 1  in unplugged position and in  FIG. 2  in plugged-in position. The connector member  1  is connected to the connecting lead  3  by means of which current/voltage is supplied to the female connectors  4 . 
     The connector member  2  is provided with the heating tape  5  that, like the connecting lead  3 , is extending out of the connector member. The heating tape  5  is electrically connected with male connectors  6  which engage the female connectors  4  when the connector members  1 ,  2  are plugged in ( FIG. 2 ). 
     The female connectors  4  of the connector member  1  project partially into a receiving space  7  which is delimited by a part of the housing  8  of the connector member  1 . The connector member  2  engages with a head part  9  the receiving space  7 . The head part  9  is form-fittingly secured in the receiving space  7  and is resting with its outer wall  10  against the inner wall  11  of the receiving space  7 . 
     The head part  9  is provided on its exterior side with a circumferential seal  12  which is accommodated in an annular groove  13  that is open toward the end face of the head part  9 . The seal  12  covers also a part of the end face  14  of the head part  9 . In the plugged-in state, the seal  12  is seal-tightly resting against the inner wall  11  of the receiving space  7 . 
     The connector member  2  is comprised of three component groups  15  to  17  ( FIG. 3 ). The component group  17  has a receiving space  18  which is open at the end face and is closed off by a bottom  19 . A heating tape  5  projects though it into the receiving space  18 . The component group  17  comprises the head part  9  with the described seal  12 . 
     Into the component group  17 , the component group  16  is inserted which is arranged with form fit in the receiving space  18 . The component group  16  is inserted so far that with its end face  20  it contacts the bottom  19  of the component group  17  ( FIG. 4 ). In the component group  16 , there is a sealing device  36  with which the heating tape  5  is sealed in the entry area into the component group  16  in a way to be described in the following ( FIGS. 10 to 13 ). This device is designed such that the heating tape  5  initially loosely projects through the through opening  21  so that it can be connected easily with the male connectors  6 . 
     The component group  16  is provided with a shaped seal  22  with which the heating tape  5  is sealed. Also, with the shaped seal  22  the component group  16  is sealed near the bottom  19  relative to the component group  17 . 
     The component group  16  is completely accommodated within the receiving space  18 . In a final mounting step, the component group  15  provided with the male connectors  6  is inserted into the receiving space  18 . The component group  15  has a cover  23  with which, in the mounted position ( FIG. 5 ), it is resting with interposition of the seal  12  on the end face of the head part  9  of the component group  17 . The cover  23  projects past a housing part  24  that extends with a tapering end  25  between the free end  26  ( FIG. 3 ) of the component group  16  and the inner wall  27  ( FIG. 3 ) of the receiving space  18 . At the transition to the free end  25 , the housing part  24  is provided with a circumferential outer step  28  with which the component group  15  comes to rest on a step  29  in the inner wall  27  of the receiving space  18 . 
     The head part  9  of the component group  17  is provided at the end face with at least one locking element  31  with which the component group  15  is locked in the mounted position. The cover  23  of the component group  15  is provided with at least one counter locking element (not illustrated) that is interacting with the locking element  31 . The male connectors  6  are projecting through the cover  23  of the component group  15 . 
     The component groups  15 ,  16  each are formed as plug-in component groups which can be mounted by simple plug-in processes in the component group  17 . 
     The connector member  1  ( FIGS. 6 and 7 ) comprises the component group  32  into which the component group  33  is inserted. The component group  32  comprises a housing  34  with a receiving space  35  for the component group  33  and a sealing device  36  which will be explained in more detail with the aid of  FIGS. 10 to 13 . The sealing device  36  is inserted so far into the receiving space  35  that it contacts the bottom  37  of the receiving space  35 . 
     The component group  33  is substantially of the same configuration as the component group  15 . The component group  33  comprises a cover  38  that projects past a housing part  39  on all sides and, in the mounted position ( FIG. 7 ), is resting on a circumferential step  40  in the inner wall  41  of the receiving space  35 . The housing part  39  is resting against the inner wall  41  of the receiving space  35  in the area between the step  40  and the sealing device  36 . The tapering free end  42  of the housing part  39  is positioned on the outer side of a stop sleeve (securing part)  43  of the sealing device  36 . 
     Through an opening  45  in the bottom  37  of the housing  34  of the component group  32 , the connecting lead  3  is projecting whose leads are electrically connected with the female connectors  4 . By means of the sealing device  36 , the connecting lead  3  is reliably sealed within the receiving space  35 . 
     In the bottom part of the housing  34 , a strain relief device  44  is accommodated as will be explained in more detail with the aid of  FIGS. 14 to 16 . The cover  38 , as has been explained with the aid of the component group  15 , is locked with the housing part  39 . 
     At one end of the heating tape  5  ( FIGS. 8 and 9 ) the insulation is removed. Onto this end  46  without insulation, an insulation element  47  is attached. It comprises a sleeve part  48  which is matched to the circumference of the heating tape  46  without insulation and is seated fixedly on the heating tape  5 . The heating tape  5  comprises in an exemplary fashion two litz wires  49 ,  50  which are connected electrically to the male connectors  6 . The parts of the litz wires  49 ,  50  without insulation are surrounded across the greatest portion of their length by the hose-shaped insulating parts  51 ,  52  which are advantageously formed monolithically with the sleeve part  48 . The insulating parts  51 ,  52  are seated fixedly on the litz wires  49 ,  50 . 
     In the area between the insulating parts  51 ,  52 , the insulating element  47  is provided with a reservoir  53  for an electrically insulating sealing medium  54 . The sealing medium is advantageously an electrically insulating gel. 
     The reservoir  53  is closed off by a plunger  55 . The reservoir  53  is located in a center part  56  of the insulating element  47 . Advantageously, the center part  56  is in the area between the insulating parts  51 ,  52  and is advantageously monolithically formed therewith. The plunger  55  closes off the reservoir  53  at the free end of the center part  56 . At the other end, a nozzle-shaped opening  57  with only minimal cross-section opens into the reservoir  53  and penetrates the bottom of the center part  56 . 
     The center part  56  of the electrical insulation element  47  is spaced from the heating tape  5  so that between them a sealing space  58  is formed which is empty before connecting the heating tape  5  to the male connectors  6 . The sealing space  58  is penetrated by the litz wires  49 ,  50 . In their area, the sealing space  58  is provided with conical sealing spaces  59 ,  60  through which the litz wires  49 ,  50  are extending. 
     When the heating tape  5  is connected to the male connectors  6 , the plunger  55  with its head  61  will contact the bottom  62  of the housing part  24  of the component group  15 . Upon assembly, the plunger  55  is pushed into the reservoir  53  to such an extent that, with the heating tape  5  mounted, it is resting with its head  61  on the end face  63  of the center part  56 . The dimensions are such that the head  61  is resting on the bottom  62  of the housing part  24  as well as on the end face  63  of the center part  56  ( FIG. 9 ). The sealing medium  54  which is contained within the reservoir  53  is displaced by the plunger  55  via the opening  57  into the sealing spaces  58  to  60 . The quantity of sealing medium  54  as well as the volume of the sealing spaces  58  to  60  are matched to each other such that the sealing spaces are completely filled by the sealing medium  54 . This sealing medium prevents that moisture can collect in the area of the sealing spaces  58  to  60 . Accordingly, in case of moist or wet conditions of use of the heating tape  5 , it is prevented that, as a result of capillary action, moisture can penetrate which could lead to an electrically conducting creeping path between the two litz wires  49 ,  50  and thus to dangerous leakage currents. The sealing medium  54  prevents thus in the worst case that short-circuiting occurs whereby the heating tape  5  and thus the entire plug connector would be destroyed. 
     The plunger  55  is resting against the wall of the center part  56  in such a way that no sealing medium  54  can escape past the plunger  55 . 
     In the initial position according to  FIG. 8 , the plunger  55  is positionally secured. At the free end of the center part  56  an inwardly projecting circumferential rim  64  is provided that engages an annular groove  65  at the circumference of the plunger  55 . 
     The plunger  55  has at least one further annular groove  65  in the area of the underside of the head  61 . Into it, the rim  64  of the center part  56  engages when the litz wires  49 ,  50  are connected to the male connectors  6 . 
     In the embodiment, the plunger  55  is also provided with a further annular groove  65  so that it can be maintained in an intermediate position. 
     In the end position according to  FIG. 9 , the plunger  55  is not only secured by engagement of the rim  64  of the center part  56  but also by contact of the head  61  of the plunger  55  on the bottom  62  of the housing part  24 . 
     This sealing action cannot only be used in case of the heating tape  5  but also for the connecting lead  3 . 
     The sealing device  36  in the connector member  2  has a sealing body  66  ( FIG. 10 ) that forms the shaped body  22  ( FIG. 3 ) which is arranged in the receiving space  18  of the base member  17 . In the installed position, the sealing body  66  is resting on the bottom  19  which is provided at the inner side, at a spacing from the inner wall  27  of the receiving space  18 , with an annular projection  67  which engages an annular groove  68  of the sealing body  66 . Accordingly, the sealing body  66  is positionally secured in radial direction within the receiving space  18 . The annular groove  68  is located at the underside of an annular disk  69  of the sealing body  66 . 
     An annular part  70  adjoins the radial outer rim of the annular disk  69  and an annular part  71  adjoins the radial inner rim of the annular disk  69 . Both annular parts  70 ,  71  are formed monolithically with the annular disk  69 . The outer annular part  70  is provided at its outer side with a corrugated profile  72 . With it, it is resting seal-tightly against the inner wall  27  of the receiving space  18 . 
     The inner annular part  71  which is longer in axial direction of the sealing body  66  is also provided on the inner side with a corresponding corrugation profile  73 . It extends from the free end only across a part of the axial height of the annular part  71 . Adjoining the annular disk  69 , the inner annular part  71  is resting with its inner side against an annular wall  74  which is projecting from the bottom  19  into the receiving space  18  and delimits an insertion opening  75  for the heating tape  5 . 
     The inner annular part  71  of the sealing body  66  has a slanted end face  76  interacting with a wedge slider  77 . It is axially slidably supported within a securing part  78 . 
     The securing part  78  has an annular wall  79  which is resting against the inner wall  27  of the receiving space  18 . The wedge slider  77  is resting with its exterior side of the wall  80  against the inner side of the wall  79 . The wall  80  adjoins the wedge member  81  which is of an annular shape and whose end face wedge surface  82  is interacting with the conical end face wedge surface  76  of the sealing body  66 . The wedge member  81  has a smaller outer diameter than the wall  80 . 
     The annular wall  80  of the wedge slider  77  has two depressions  83  in which a pressure spring  84  is positioned, respectively. The pressure springs  84  are supported with one end on the bottom of the depressions  83  and with the other end on a pressure member  85  that is slidably guided within the securing part  78 . The pressure member  85  is resting on an actuating element  86  that is guided also on the inner side of the wall  79  of the securing part  78 . The actuating element  86  is a component of the component group  15  that is inserted into the component group. During this insertion process, the pressure member  85  is displaced by the actuating element  86 . 
       FIG. 10  shows the sealing device  36  in the initial position. The sealing body  66  is positioned with the outer annular part  70  on the inner wall  27  of the receiving space  18  while the inner annular part  71  has a spacing relative to the heating tape  5 . The sealing body  66  is seated on the projection  67  wherein the annular disk  69  of the sealing body  66  has a spacing relative to the bottom  19 . The wedge slider  77  contacts the conical end face  76  of the annular part  71 . When the component group  15  is inserted with the actuating element  86  into the component group  17 , the wedge slider  77  is displaced by means of the pressure member  85  and the pressure springs  84 . The wedge surface  82  of the wedge slider  77  pushes onto the conical end face  76  of the inner annular part  71  and displaces thereby the sealing body  66  axially to such an extent that it is contacting with its annular disk  69  seal-tightly the bottom  19  of the component group  17  ( FIG. 11 ). The part of the inner annular part  71  of the sealing body  66  which is projecting past the annular wall  74  of the component group  17  is deformed in radial inward direction elastically to such an extent that it contacts seal-tightly with its inner side the heating tape  5 . 
     The pressure springs  84  are pretensioned such that the sealing body  66  ensures the sealing action of the heating tape  5  even after long periods of use. The sealing body  66  and the sealing wedge  77  are matched to each other such that over an extended period of use of the plug connector a sufficiently large retensioning travel is available. In this way, it is ensured that the annular part  71  of the sealing body  66  is seal-tightly resting about the circumference of the heating tape  5 . 
     The wedge slider  77  is properly guided within the securing part  78 . The securing part  78  has a terminal area  87  with which it engages between the two annular parts  70 ,  71  of the sealing body  66 . The terminal area  87  is designed such that the two annular parts  70 ,  71  with their outer sides facing each other are resting areally against the outer sides of the terminal area  87  and the annular disk  69  of the sealing body  66  in the initial position ( FIG. 10 ) is resting areally against the end face of the terminal area  87 . The terminal area  87  ensures in this way that upon displacement and upon elastic deformation of the sealing body  66  the two annular parts  70 ,  71  are each held in or moved into their sealing position. Advantageously, the terminal area  87  tapers conically in the direction of its free end. In the plugged-in position, the annular disk  69  of the sealing body  66  has a minimal spacing from the end face of the terminal area  87  of the securing part  78  ( FIG. 11 ). The terminal area  87  overlaps the annular wall  74  of the component group  17 , viewed in radial direction ( FIGS. 10 and 11 ). In this way, it is ensured that in particular the inner annular part  71 , when it is elastically deformed, remains clamped between the terminal area  87  and the annular wall  74  so that the inner annular part  71  is deformed reliably in radial inward direction for seal-tight contact on the heating tape  5 . 
     With the sealing body  66  and the wedge slider  77  a targeted elastic deformation is achieved. The spring forces may be minimal. They are only adjusted to be so high that the annular part  71  of the sealing body  66  is resting in radial inward direction seal-tightly on the heating tape  5 . The spring force can be relatively minimal because the radial deformation is achieved by the wedge surface  82  of the wedge slider  77 . As a result of the radial deformation by means of the described wedge effect, the inner annular part  71  is substantially moved only radially against the heating tape  5  so that at the contact locations between the annular part  71  and the heating tape  5  no flexing effect occurs. Such flexing actions occur in known seals because they deform in circumferential direction whereby leakages occur so that the medium can reach the litz wires of the heating tape  5 . 
     In the initial position of  FIG. 10 , the heating tape  5  is still freely movable in the component group  17  because the annular part  71  of the sealing body  66  has a spacing relative to the heating tape. It can therefore be simply displaced into the position that is beneficial for assembly. Only upon insertion of the component group  15 , the annular part  71  is deformed in the described way by means of the ramp that is formed by the interacting wedge surfaces  76 ,  82  in radial inward direction until sealing contact on the heating tape  5  occurs. In the installed position, the pressure springs  84  exert a sufficiently high force so that the annular part  71  is resting seal-tightly on the heating tape  5 . 
     The corrugation profiles  72 ,  73  on the two annular parts  70 ,  71  are designed in axial section approximately of a semi-circular shape. The two corrugation profiles have thus an O-ring-like contour which ensures a proper sealing action. In the inserted position, this O-ring-like contour is moreover elastically deformed so that a high sealing action is achieved. 
     Since the sealing body  66  is pretensioned by the pressure springs  84 , the plug connector can be used also in a wide temperature range without problems without the sealing action being impaired. Thus, the described plug connector is for example suitable for a temperature range of approximately −60° C. to approximately +180° C. Since in this temperature range the material properties as well as the dimensions of the individual parts of the component group will change, by means of the described elastic deformation of the sealing body  66  in combination with the pretensioned pressure springs  84  it is ensured that a good sealing action is ensured any time. 
     In the installed position ( FIG. 11 ), the wedge member  81  of the wedge slider  77  extends across the terminal area  87  of the securing part  78 . The wedge member  81  has a straight outer side  88  in axial section with which the wedge member  81  is contacting an appropriate inner surface  89  of the terminal area  87  of the securing part  78 . As a result of this overlap, it is ensured that the securing part  78  in the area of the terminal area  87  is not deformed in radial inward direction. At the same time, with this overlap it is ensured that the annular part  71  in the elastically deformed area is forced safely against the heating tape  5 . 
     In the embodiment according to  FIGS. 10 and 11 , the sealing device  36  is provided with two oppositely positioned pressure springs  84 . 
     In the embodiment according to  FIGS. 12 and 13 , only a single pressure spring  84  is used instead which surrounds the heating tape  5  with play. In other respects, this embodiment is of the same configuration as the embodiment according to  FIGS. 10 and 11 . In the initial position ( FIG. 12 ) the heating tape  5  can be displaced easily in the longitudinal direction because the inner annular part  71  of the sealing body  66  has a spacing relative to the heating tape  5 . When the component group  15  ( FIGS. 3 to 5 ) is inserted into the component group  17 , then its actuating element  86  pushes on the pressure member  85  and displaces it to such an extent that it is contacting the wedge slider  77 . By means of the wedge member  81 , the annular part  71  is elastically inwardly deformed in the described way to such an extent that it seal-tightly comes to rest against the heating tape  5 . 
     With the two described embodiments of sealing devices  36 , heating tapes  5  with different outer dimensions can be sealed. With the sealing device  36  not only the heating tape  5  is sealed but also the area of the downstream terminals  90  ( FIG. 1 ). Also, the areas of the male connectors  6  or the female connectors  4  are in this way protected against penetration of moisture and the thus resulting leakage currents. 
     With the aid of  FIGS. 10 to 13 , the sealing action of the heating tape  5  has been described. As shown in  FIGS. 1 and 2 , the sealing device  36  is however also provided in the connector member  1  for sealing the connecting lead  3 . It can also be sealed simply in the described way wherein the sealing action is reliably ensured across the described great temperature range. 
     The strain relief device  44  is provided on both connector members  1 ,  2  for the connecting lead  3  as well as the heating tape  5  ( FIGS. 1 and 2 ) and will be explained in more detail with the aid of  FIGS. 14 to 16 . 
     The connecting lead  3  or the heating tape  5  is clamped between four pressure members  91  to  94 . In this way, a four-point strain relief action is provided. The pressure members  91  and  92  are approximately of the same configuration and arranged mirror-symmetrical to each other. The oppositely positioned pressure members  93  and  94  are embodied identically but are mirror-symmetrically arranged relative to each other. For this reason, in the following only one of the pressure members  91  and  93  will be explained in more detail. 
     The pressure member  91  has a block-shaped base member  95  with two lateral surfaces  96 ,  97  that are parallel to each other. The underside  98  extends substantially straight while the opposite top side  99  is convexly curved across its length. The base member  95  has at both ends narrow sides  100 ,  101  that are parallel to each other and adjoin at a right angle the lateral surfaces  96 ,  97 . 
     The two lateral surfaces  96 ,  97  are provided with recesses  102 ,  103  of which in  FIG. 14  only one recess  103  can be seen. The recess  102  which is located in the narrow side  96  is embodied identically to the recess  103 . These recesses  102 ,  103  taper from the underside  98  in the direction of the top side  99  of the base member  95 . In each one of the recesses, there are two grooves  104 ,  105  that extend, converging relative to each other, from the underside  98  and extend across the height of the recess  102 ,  103 . 
     The base member  95  is penetrated by two openings  106 ,  107  that are parallel to each other as well as perpendicular to the underside  98 . Through these openings  106 ,  107 , screws  108 ,  109  are inserted with which in connection with the threaded bushings  110 ,  111  the two pressure members  91  and  92  are linked with each other. Since the pressure members  93 ,  94  are connected with form fit with the pressure members  91 ,  92 , the pressure members  93 ,  94  are also secured by means of the screws  108 ,  109  and the threaded bushings  110 ,  111 . 
     At half the length, on the lateral surfaces  96 ,  97 , a rib  112 ,  113  is provided, respectively, which extends in the vertical direction from the bottom side  98  to the top side  99  of the base member  95  and separates the two grooves  104 ,  105  from each other. The ribs  112 ,  113  project past the lateral surfaces  96 ,  97 . 
     At half the length, the bottom side  98  of the base member  95  is provided with a recess  114  which is matched to the contour of the connecting lead  3  or of the heating tape  5 . On either side of the recess  114 , two projections  115 ,  116  extend past the bottom side  98 . The projections  115 ,  116  extend across the width of the underside  98  and serve as stops with which the pressure members  91 ,  92  may come to rest on each other. The projections  115 ,  116  are so high that in contact position the connecting lead  3  or the heating tape  5  positioned therebetween is not deformed in an impermissibly strong way. 
     The pressure members  93 ,  94  are designed as sliding wedges that are slidable perpendicular to the pressure members  91 ,  92 . The pressure members  93 ,  94  comprise a flat clamping piece  117  whose end face clamping surface  118  ( FIGS. 15 and 16 ) is matched to the contour of the connecting lead  3  or the heating tape  5 . 
     From the top side and bottom side of the clamping piece  117 , two flat webs  119 ,  120  are projecting along its longitudinal side that each are of a triangular configuration. The triangle sides that are facing the connecting lead  3  or the heating tape  5  of all webs  119 ,  120  are positioned in a common plane. Near the top triangle tip the webs  119 ,  120  are provided with cams  121 ,  122  on their inner sides that are facing each other. The cams  121 ,  122  engage the grooves  104 ,  105  of the pressure members  91 ,  92 . 
     In the area between the pressure members  91 ,  92 , a pressure spring  123 ,  124  is seated, respectively, on the screws  108 ,  109  and is supported with its ends on oppositely positioned bottom sides  98  of the pressure members  91 ,  92 . In the mounted position of the strain relief device  44 , the pressure springs  123 ,  124  are pretensioned. 
     The screws  108 ,  109  are positioned recessed with their screw head  125 ,  126  in the openings  106 ,  107  of the pressure member  91  ( FIGS. 15 and 16 ). For contacting the screw head  125 ,  126 , the openings  106 ,  107  are provided with a step  127 ,  128 , respectively, on which the screw head  125 ,  126  is resting. 
     The threaded bushings  110 ,  111  are positioned recessed in the openings  106 ,  107  of the base member  95 . These openings are matched to the shape of the threaded bushings  110 ,  111  such that the latter are resting areally across their length against the inner wall of the openings  106 ,  107 . 
     The screws  108 ,  109  are screwed in initially only so far into the threaded bushings  110 ,  111  that the pressure members  91  to  94  have a spacing relative to the connecting lead  3  or to the heating tape  5  ( FIG. 15 ). When the connecting lead or the heating tape assume their final position, the screws  108 ,  109  are screwed farther into the threaded bushings  110 ,  111 . In doing so, the pressure members  91 ,  92  approach each other. At the same, the sliding wedges  93 ,  94 , as a result of the engagement of their cams  121 ,  122  in the grooves  104 ,  105 , are also moved toward each other. The grooves  104 ,  105  in the pressure members  91 ,  92  extend at 45° relative to the ribs  112 ,  113  so that the sliding wedges  93 ,  94  are displaced uniformly together with the pressure members  91 ,  92  against the connecting lead  3  or the heating tape  5 . The screws  108 ,  109  are screwed in to such an extent that the pressure members  91  to  94  fixedly clamp the connecting lead  3  or the heating tape  5  sufficiently ( FIG. 16 ). By means of the four pressure members a 4-point strain relief action is realized wherein they are resting at locations of the connecting lead  3  or of the heating tape  5  that are rectangularly positioned relative to each other. 
     The pressure springs  123 ,  124  ensure that the pressure members  91  to  94  are automatically returned upon unscrewing the screws  108 ,  109 . The pressure members  93 ,  94  are moved away from each other as a result of their mandatory guiding action in the pressure members  91 ,  92 . 
     The triangular webs  119 ,  120  of the pressure members  93 ,  94  are positioned in the recesses  102 ,  103  of the pressure members  91 ,  92 . The webs  119 ,  120  are so narrow that they do not project, or only project a little, from the recesses  102 ,  103 . The strain relief device  44  therefore occupies only little space. 
     As shown in  FIGS. 1 and 2 , the strain relief devices  44  in the connector members  1 ,  2  are arranged near the inlet opening of the connecting lead  3  or of the heating tape  5  in appropriate receiving spaces  129 ,  130 . 
     With the 4-point clamping action, the connecting line  3  or the heating tape  5  is always centrally clamped. Accordingly, the connecting lead  3  or the heating tape  5  are also guided centrally through the inlet opening of the connector members  1 ,  2  into the interior. Since a 4-point clamping action is realized, the connecting lead  3  or the heating tape  5  are not changed, or changed only a little, with regard to their circumferential shape contour. The four points of attack of the pressure forces lead to a reliable and high strain relief action so that even at higher tension forces there is no risk that the connecting lead  3  or the heating tape  5  is pulled out of the connector members  1 ,  2 . 
     The strain relief device  44  ensures also that the heating tape and the connecting lead are centered exactly relative to the sealing device and therefore also a proper sealing action is ensured.