Abstract:
This invention relates to a device ( 2 ) for establishing an electroconductive contact with an especially elongated, for example substantially cylindrical body, for example a pipe or a cable. The inventive device comprises a base body ( 4 ) that consists at least partially of an elastic material and that is meant to be put on the body to be contacted. A contact element ( 22 ) that is held, when mounted, on a side of the body to be contacted facing the base body ( 4 ), is designed to establish an electroconductive connection with the body to be contacted. According to the invention, retainers are integrally formed with the elastic material and substantially positively enclose the contact element ( 22 ) at least on two opposite zones of its rim on the side facing away from the base body ( 4 ), thereby retaining it on the base body ( 4 ).

Description:
FIELD OF THE INVENTION 
   The invention relates to a device for establishing electrically conductive contact with an electrically conductive part of an elongated, e.g. a substantially cylindrical body, for instance a pipe or a cable. 
   Such devices are used, for instance, to connect a metallic pipe or a stripped outer conductor of a coaxial cable to a ground cable. 
   BACKGROUND OF THE INVENTION 
   EP 0 744 788 A1 discloses a device of this type, which comprises a main body that is applied to a body to be contacted and a contact element to establish an electrically conductive connection with the body to be contacted. This contact element is held by retention means on a side of the main body that faces toward the body to be contacted when mounted. In this prior-art device, the main body has a strip-shaped metallic clamp, which is embedded in an elastic material. On the side that faces toward the body to be contacted when mounted, a contact surface is left free for the contact element. The contact element in this prior-art device is formed by a strip of copper braiding. The retention means for holding the contact element to the main body in this prior-art device is formed by an adhesive or a weld joint. In the desired mounting position, the longitudinal edges of the contact element extend substantially parallel to the adjacent edges of the main body. 
   When the contact element is mounted to the main body by means of a weld joint, there is a risk that the contact element may be detached from the main body and may be lost. A new contact element must then be procured before the device can be mounted. This is time consuming and increases the cost of both material and installation. 
   Mounting the contact element by means of an adhesive has the drawback that it undesirably increases the electrical resistance between the contact element and the strip-shaped metallic clamp of the main body. 
   OBJECTS AND SUMMARY OF THE INVENTION 
   The object of the invention is to define a device of the type described above, the production of which is simplified. 
   The fundamental idea of the teaching according to the invention is to form the retention means onto the elastic material of the main body. According to the invention, these retention means comprise at least one retention part that is formed onto the elastic material of the main body. This retention part extends from one edge of the contact element to the opposite edge thereof, such that the retention part overlaps the contact element on its side facing away from the main body and thus holds it to the main body. In this manner, the contact element is held on the main body in a substantially form-fitting manner. 
   The inventive embodiment thus makes separate retention means, e.g. in the form of an adhesive, a weld joint or a clamping component, basically unnecessary. As a result the construction of the inventive device is simplified and the device can be produced more cost-effectively. If any additional fixation of the contact element is desired, e.g. by means of an adhesive, this additional fixation can be effected over a smaller surface than in the prior-art devices. 
   The retention means can be embodied in any suitable manner, e.g. in the form of narrow strips of an elastic material, which are formed onto the elastic material of the main body and extend perpendicularly across the retention element on its side facing away from the main body. A highly advantageous further development of the teaching according to the invention provides that the retention part forms a substantially pocket-like receptacle for the contact element. To mount the contact element to the main body in this embodiment, it is inserted into the pocket-like receptacle and can thus be mounted faster and more easily to the main body. 
   A further development of the aforementioned embodiment provides that the retention part has an opening that forms the pocket-like receptacle. This opening can be formed in the retention part, for instance during injection molding of the main body and the retention means. 
   Another further development provides that the pocket-like receptacle be formed between two surfaces of the retention part facing one another and the main body. In this embodiment, the retention part can be configured, for instance, as a flat strip made of an elastic material. 
   In principle, it is sufficient if the retention means have a single pocket-like receptacle. An advantageous further development of the embodiment with the pocket-like receptacle provides, however, that the retentions means comprise two retention parts that are spaced apart from one another and form pocket-like receptacles facing one another for receiving opposite ends of the contact element. In this embodiment, the opposite ends of the contact element are each received in a pocket-like receptacle, such that the contact element is held particularly securely on the main body. 
   Another advantageous further development of the embodiment with the pocket-like receptacle or receptacles provides that these receptacles are shaped substantially complementary to the corresponding end of the contact element. Thus, the end or ends of the contact element are held tightly within the receptacle. 
   Another embodiment provides, that the retention part be configured as a flat strip, which overlaps the contact element at a point remote from its ends. 
   Another advantageous further embodiment of the teaching according to the invention provides that the retention means comprise at least one web that is formed onto the elastic material of the main body and rests against the contact element at a point remote from the pocket-like receptacle or receptacles. The web or webs make it possible to adjust the contact element relative to the main body or to achieve an additional fixation of the contact element on the main body. 
   It is particularly advantageous if at least two webs are provided against which the contact element rests with opposite areas of its edge. In this embodiment, the contact element is held between the webs and is thus secured against any movement in the direction of the webs. 
   The shape, size and material of the contact element can be selected within wide limits. If the inventive device is used to contact an elongated, e.g. a substantially cylindrical body, for instance a metal pipe or a stripped outer conductor of a coaxial cable, it is useful if the contact element has an elongated shape. When mounted, the contact element then extends in circumferential direction of the body to be contacted and can, for instance, establish electrically conductive contact with the body to be contacted over a substantial part of the circumference thereof 
   In the embodiment with the elongated contact element and the pocket-like receptacles, the ends of the contact element are advantageously inserted into the pocket-like receptacles, as provided for in a further development. When a cylindrical object is contacted, e.g. a stripped outer conductor of a coaxial cable, the contact element is thus held in the pocket-like receptacles by its ends in circumferential direction. 
   If, for instance, a cable is to be contacted, and the contact element has to be fixed not only in circumferential direction but also in axial direction, it is advantageous in the embodiment with the web or webs if the contact element rests against the web along one of its longitudinal edges or along both of its longitudinal edges. 
   The material of the main body can be selected within wide limits. The main body can also be made of a plurality of materials. One embodiment provides that the main body comprises a carrier element that is made of metal to increase the stability of the main body. 
   In the aforementioned embodiment, the carrier element is advantageously strip-shaped. Thus, the main body of the device according to the invention can, for example, be made flexible. 
   Another further development of the teaching according to the invention provides that the carrier element is permanently connected with the part made of the elastic material, or that the carrier element is coated with the elastic material of the main body, particularly on its side that faces away from the body to be contacted when mounted, or that it is embedded in the elastic material of the main body. On the side of the carrier element that faces toward the body to be contacted when mounted, a contact surface for the contact element is left free. This embodiment can be produced easily and cost-effectively. 
   The shape and size of the main body can be selected within wide limits. To contact a plate-like body, the main body can, for instance, be plate-shaped, and to contact a bent or curved body, it can have a bent or curved shape. 
   A further development that is particularly advantageous for contacting pipes or cables of any cross section provides that the main body be configured in such a way that it encircles the body to be contacted in the form of a ring or a sleeve when mounted. In this embodiment, the main body is held securely on the body to be contacted. 
   In principle, the main body can be rigid, but it is advantageous, if it is flexible. This makes it easier to mount the device on the body to be contacted. 
   The main body can have a multi-part configuration. In an inventive device that is provided for contacting a pipe, the main body can be made, for instance, of a plurality of consecutive parts in circumferential direction of the pipe to be contacted, e.g. two half ring-shaped parts. However, the main body is advantageously configured as a single part, which is open in circumferential direction and at its free ends is provided with angled or bent straps, which when mounted can be connected with one another, preferably by means of a screwing or clamping device. In this embodiment, due to the one-piece configuration of the main body, the inventive device can be particularly easily mounted. 
   Another further development provides that the main body be configured as a clamp, which can be tightened around the body to be contacted. This further facilitates mounting. 
   Another further development of the embodiment with the carrier element provides that the carrier element has at least one opening, preferably at least one opening on either side of the contact element, through which the elastic material extends, such that the elastic material on the side of the carrier element that faces toward the contact element is connected with the elastic material on the side of the carrier element that faces away from the contact element. This is to prevent the elastic material from becoming detached from the carrier element on the side of the carrier element that faces toward the contact element. This kind of detachment could impair the electrical contact between the contact element and the carrier element. 
   To prevent air and/or moisture from penetrating into the contact area, a further development provides that the device be equipped with sealing means to seal a space that forms between the body to be contacted and the main body when mounted against air and/or moisture penetration. 
   An advantageous further development of the invention with the sealing means provides that the sealing means have sealing lips made of an elastic material which are arranged on a side of the main body that faces toward the body to be contacted when mounted and are spaced apart from one another perpendicularly to the longitudinal direction of the main body or the axial direction thereof. These sealing lips extend in longitudinal direction of the main body or in its circumferential direction, preferably substantially over the entire length of the main body in this direction, and form a seal relative to the body to be contacted when the device is mounted. This embodiment is simple in its design and provides a reliable seal of the contact. 
   In the aforementioned embodiment, the retention means are advantageously formed onto the sealing lips, which further simplifies the construction. 
   The contact element can be configured in any suitable manner, e.g. as a flexible wire or a braided metal strip. A particularly advantageous further development of the teaching according to the invention provides that the contact element be made of a profiled piece of sheet metal. In this embodiment, the production of the inventive device is made surprisingly simpler and thus more cost effective. The contact element can be made, for instance, of profiled sheet metal which is produced by the yard and which can be simply cut to the required length of the contact element as a function of the size of the inventive device. In addition, the inventive contact element made of profiled sheet metal is particularly inexpensive. This reduces the production costs of the inventive device. The contact element can be made of any suitable type of sheet metal that has sufficient electric conductivity, e.g. brass, steel or copper sheet. 
   The profile of the contact element can be selected within wide limits to meet the corresponding requirements. The contact element is advantageously provided with a substantially wavy or meander-like or zigzag-shaped profile, as provided for by one embodiment. This embodiment is simple and cost effective to produce. Due to the substantially wavy, meander-like or zigzag-shaped profile, the contact element fits securely on the body to be contacted even if component tolerances of the mounted device are relatively large. 
   A further development of the aforementioned embodiment provides that the profile of the contact element consists of successive peaks and valleys that are round, arched, triangular, or trapezoidal in cross section. The shape of the peaks and valleys can be selected within wide limits as a function of the respective requirements. 
   The profile of the contact element can be irregular along its extent or uniform only in sections. Advantageously, however, the profile is substantially uniform over the entire length of the contact element. This facilitates production of the contact element and ensures uniform contact between the contact element and the body to be contacted when the device is mounted. For instance, when a stripped outer conductor of a HF cable is contacted in the mounted position of the device, irregular loading of the outer conductor in circumferential direction, which could lead to undesirable reflections of a signal transmitted via the cable, is prevented due to the uniform profile of the contact element in circumferential direction. 
   Another particularly advantageous further development of the embodiment with the contact element made of profiled sheet metal provides that the contact element be unprofiled or flattened along its ends in longitudinal direction. This makes it easier to mount the contact element on the main body. If the ends of the contact element are held, for instance, in pocket-like receptacles, it is easier to insert the flattened ends into the receptacles and thus easier to mount the contact element on the main body. In this embodiment, mounting can be done not only by hand as in the prior-art devices but in principle also by machine. 
   In principle, the contact element can be substantially rigid. A further development provides, however, that the contact element be elastically deformable such that it fits elastically resiliently against the electrically conductive part of the body to be contacted. In this embodiment, due to the elastic resilient fit of the contact element on the electrically conductive part, a particularly secure electrically conductive connection is achieved. Furthermore, the resilient fit readily compensates component tolerances of the inventive device and/or the body to be contacted. 
   Another further development of the embodiment with the carrier element provides that the profile of the contact element forms consecutive projections with which the contact element preferably alternately fits against the body to be contacted and the carrier element when the device is mounted, such that an electrically conductive connection is established between the body to be contacted and the carrier element. In this embodiment, the projections produce a particularly reliable electrically conductive connection between the body to be contacted and the carrier element, which in turn can, for instance, be connected with a ground cable. 
   Depending on the corresponding requirements, the contact element can be permanently connected with the main body. 
   The contact element can also be detachably connected with the main body, as provided for by a further embodiment. This makes it easier to install the contact element on the main body and, if necessary, to deinstall it again. 
   According to another embodiment, the contact element can be permanently connected with the elastic material of the main body. 
   Another especially advantageous further development of the teaching according to the invention provides that the elastic material of the main body, on its side facing toward the contact element, has a contact surface for the contact element, which is substantially complementary to the contact element such that the contact element rests over substantially its entire length against the elastic material of the main body. In this manner, a particularly reliable fit of the contact element on the electrically conductive part of the body to be contacted is achieved when the device is mounted. The elastic material of the main body furthermore creates an elastic resilient fit of the contact element against the electrically conductive part of the body to be contacted. 
   In the aforementioned embodiment, the contact element can be connected with the elastic material of the main body in any suitable manner. For example, the part that is made of the elastic material can be an extruded strip material with which the contact element is connected. However, an advantageous further development provides that the contact element be coated by the elastic material of the main body. This embodiment is simple and cost effective to produce. It also ensures that the contact surface of the main body is shaped complementary to the profile of the contact element. 
   A further development of the embodiment with the one-piece main body and the straps provides that the contact element extends up to the straps. In this embodiment, e.g. a ground cable can be connected with the straps such that an electrically conductive connection is established via the contact element between the ground cable and the electrically conductive part of the body to be contacted, e.g. a stripped outer conductor of a coaxial cable. 
   Finally, a further development of the teaching according to the invention provides that the elastic material of the main body and/or the sealing lips be made of an elastomer, particularly vulcanized rubber, and/or a thermoplastic elastomer. These materials can be processed easily and cost effectively and are highly resistant against chemical and mechanical influences. 

   
     The invention will now be described in greater detail with reference to the embodiments depicted in the attached drawing. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a schematic perspective view of an exemplary embodiment of the inventive device in the form of a clamp, 
       FIG. 2  is a schematic view of the radial inner surface of the device in accordance with  FIG. 1 , 
       FIG. 3  is a section taken along line III—III in  FIG. 2 , 
       FIG. 4  is a section taken along line IV—IV in  FIG. 2 , 
       FIG. 5  is a schematic perspective view of the device according to  FIG. 1  in its mounted position, 
       FIG. 6  shows a second embodiment of a device according to the invention in the same view as that depicted in  FIG. 2 , 
       FIG. 7  is a section taken along line VII—VII in  FIG. 6 , 
       FIG. 8  is a highly schematic view of a radial section through the device according to  FIG. 6  in its mounted position, 
       FIG. 9-11  show a highly schematic view of different embodiments of the cross sections of contact elements made of profiled sheet metal, and 
       FIG. 12  shows a third exemplary embodiment of a device according to the invention in the same view as that depicted in FIG.  2 . 
   

   In the drawing figures, identical or corresponding components are provided with identical reference numerals. 
   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1  shows a first embodiment of an inventive device  2  with a flexible main body  4  configured as a clamp, which in this embodiment is a single piece and is open in circumferential direction and provided with angled straps  6 ,  8  at its free ends. When the device is mounted, these straps can be connected with one another, as will be explained in greater detail below. Device  2  serves to connect a stripped outer conductor of a coaxial cable with a ground cable and thereby to ground it, as will be explained in greater detail with reference to FIG.  5 . 
   Main body  4  comprises a substantially strip-shaped carrier element  10  that is made of metal and a part  12  that is made of an elastic material, which in this embodiment is an elastomer, in which the carrier element  10  is embedded with its axial edges and is thereby connected with part  12  made of the elastic material (cf. FIG.  3 ). 
   Part  12  made of the elastic material forms sealing lips  14 ,  16  on the side facing the body to be contacted when mounted and additional sealing lips  18 ,  20  formed respectively on the axially outer side of sealing lips  14 ,  16 . When mounted, the main body  4  with its sealing lips  14 ,  16  and its additional sealing lips  18 ,  20  fits against an outer surface of the body to be contacted so as to form a seal, such that a space, which forms between the body to be contacted and the main body  4  when mounted, is sealed against air and/or moisture penetration. 
   To retain a contact element (not depicted in  FIG. 1 ) the inventive device  2  is further provided with retention means, which will be explained in greater detail with reference to FIG.  2 . 
     FIG. 2  shows device  2  with a contact element  22 , which in this embodiment is formed by a braided metal strip and is held against the radially inner surface  24  of metal part  10  of main body  4 . 
   In this embodiment the retention means for holding the contact element  22  against main body  4  comprise parts  26 ,  28 , which are made of the same elastic material as the sealing lips  14  to  20  and part  12  and which are formed onto the inner side of sealing lips  14 ,  16  in axial direction of the main body  4 . 
   As may be seen from  FIG. 2 , part  26  extends from a longitudinal edge  27  of contact element  22  to the opposite longitudinal edge  29  thereof perpendicularly across contact element  22 . It tightly overlaps contact element  22  on its side facing away from main body  4  and thereby holds it against main body  4 . 
   Between the surfaces of part  26  and carrier element  10  facing one another, a pocket-like receptacle  30  for a free end  22  of contact element  22  is formed. This pocket-like receptacle  30  is shaped to be substantially complementary to the free end  32  of the contact element such that the latter is received snugly in receptacle  30 . Correspondingly, the surfaces of part  28  and carrier element  10  facing one another form a pocket-like receptacle  34  for receiving a free end  36  of contact element  22  opposite of free end  32 . Since the ends  32 ,  36  of contact element  22  are received in the pocket-like receptacles  30 ,  34  in circumferential direction, the contact element is substantially fixed in circumferential direction of device  2 . 
   Due to this complementary shaping of pocket-like receptacles  30 ,  34  relative to the associated ends  32 ,  36  of contact element  22 , contact element  22  in this embodiment is fixed in both circumferential and axial direction of device  2 . However, the pocket-like receptacles  30 ,  34  can also be configured in such a way that contact element  22  is received in pocket-like receptacles  30 ,  34  so that it can be shifted in both circumferential and axial direction of device  2 . In this type of an embodiment, parts  26 ,  28  can be formed by flat strips of an elastic material. 
   To fix contact element  22  in addition at a point remote from receptacles  30 ,  34 , part  26  is provided with two webs  38 ,  40 , which extend inwardly in axial direction from sealing lips  14  or  16  of main body  4  and overlap the contact element  22  on its side facing away from main body  4 . 
   Similarly, part  28  is provided with webs  42 ,  44 . 
   To fix contact element  22  to main body  4 , its one end  32  is first pushed in upward direction in  FIG. 2  under web  38 ,  40  and into the pocket-like receptacle  32 . Subsequently, the opposite end  36  of contact element  22  is pushed in downward direction in  FIG. 2  under webs  42 ,  44  and into the pocket-like receptacle  34 . In this process, contact element  22  and webs  38  to  44  are elastically deformed to the required extent. In its mounted position depicted in  FIG. 2 , contact element  22  with its side facing toward main body  4  rests against carrier element  10  thereof and is held on main body  4  in a substantially form-fitting manner in both circumferential and axial direction of main body  4  by the retention means, which are formed by the pocket-like receptacles  30 ,  34  and webs  38  to  44 . The teaching according to the invention thus enables the contact element  22  to be fixed on main body  4  in a particularly simple manner, without any adhesive, a welded joint, or the like being required for this purpose. 
   To make it easier to insert the ends  32 ,  36  of contact element  22  into the pocket-like receptacles  30 ,  34 , parts  26 ,  28  can be provided with continuous slits extending in circumferential direction of main body  4 . 
     FIG. 3  shows a section taken along a line III—III in FIG.  2 . Here it may be seen that webs  42 ,  44  are provided with undercuts  46 ,  48  and overlap contact element  22  along its opposite edges  27 ,  29 . To prevent webs  42 ,  44  from getting detached from carrier element  10  of main body  4  which would cause contact element  22  to lose contact to carrier element  10 , carrier element  10  is provided with openings  50 ,  52  in the areas of webs  42 ,  44  through which the elastic material of main body  4  extends, such that webs  42 ,  44  are connected with the elastic material on the radially outer surface of carrier element  10 . This reliably prevents webs  42 ,  44  from becoming detached from carrier element  10 . Correspondingly, openings  54 ,  56  are formed in the area of webs  38 ,  40 , and openings  58 ,  60  in the area of the pocket-like receptacle  30 , and openings  62 ,  64  in the area of pocket-like receptacle  34 . 
   From  FIG. 4 , which is a section taken along a line IV—IV in  FIG. 2 , it is apparent that pocket-like receptacle  34  is shaped substantially complementary in cross section to the free end  36  of contact element  22 . 
     FIG. 5  shows the device according to  FIG. 1  in its mounted position in which the main body  4  encircles the body to be contacted, which in this embodiment is a coaxial cable  66 , like a sleeve. To fasten the device  2  to the coaxial cable  66 , the main body  4 , which is configured as a clamp, is tightened around the coaxial cable  66  to be contacted by means of metal screws  68 ,  70 , which extend through the through-holes made in strap  6  and engage with the threaded holes made in strap  8 . 
   When main body  4  is tightened, sealing lips  14 ,  16  and the additional sealing lips  18 ,  20 , sealingly fit against jacket  72  of coaxial cable  66  in such a way that they seal the space that forms between the coaxial cable  66  and main body  4  when mounted against air and/or moisture penetration. 
   When main body  4  is tightened, contact element  22  furthermore rests against the previously stripped outer conductor  74  of coaxial cable  66  at a point remote from sealing lips  14 - 20  so that an electrically conductive connection is established between the outer conductor  74  and the carrier element  10  of main body  4  via contact element  22 . Since the carrier element  10  extends up to straps  6 ,  8 , an electrically conductive connection to a conductor, e.g. a ground cable  76 , as indicated schematically in  FIG. 5 , is established by means of screws  70 . To this end, ground cable  76  can be connected with one of screws  70  by means of a connecting eyelet  78 . 
   Thus, the desired electrically conductive connection is established between ground cable  76  and outer conductor  74  of the coaxial cable  66 , such that this outer conductor  74  is grounded. 
     FIG. 6  depicts a second embodiment of an inventive device  2 . This embodiment is distinguished from that shown in  FIG. 1  in that contact element  22 , which is held on main body  4  in pocket-like receptacles  30 ,  34  on the radially inner surface  24  of carrier element  10  is made of profiled sheet metal. In this embodiment, contact element  22  has a substantially wavy or meander-like profile, as will be explained in greater detail with reference to FIG.  8 . 
     FIG. 7 , which depicts a section taken along line VII—VII in  FIG. 2  shows that the shape of pocket-like receptacle  34  is substantially complementary to that of free end  36  of contact element  22 . 
     FIG. 8  highly schematically depicts a radial section through device  2  when mounted according to  FIG. 6 , which is taken in axial direction in an area in which contact element  22  rests against the stripped outer conductor  74  of coaxial cable  66 . From this Figure it may be seen that contact element  22  has a substantially meander-like or wavy profile. This profile of the sheet metal of which contact element  22  is made forms successive projections in the form of arched peaks and valleys of which only three are identified by reference numerals  80 ,  82 ,  84  in FIG.  5 . With these successive projections  80 ,  82 ,  84 , contact element  22  alternately rests against the stripped outer conductor  74  of coaxial cable  66  and the radial inner surface  24  of carrier element  10  of the main body. This establishes a secure electrically conductive connection between outer conductor  74  and carrier element  10  and thus also with ground cable  76  via straps  6 ,  8 . 
   Contact element  22  in this embodiment is made of a thin piece of sheet metal and is thus elastically deformable such that when device  2  is mounted it rests elastically resiliently against the outer conductor  74  and the radial inner surface  24  of carrier element  10 . 
   As may be seen in  FIG. 8 , contact element  22  in this embodiment is substantially uniformly profiled in its longitudinal direction, i.e. in circumferential direction of main body  4 . In the mounted position of device  2 , very irregular loading in circumferential direction of the outer conductor  74  of coaxial cable  66 , which in a HF cable might result in undesirable reflections of an electrical signal that is transmitted via the cable, is thereby avoided. Loading of the outer conductor  74  in circumferential direction is all the more uniform the smaller the distance in circumferential direction between the peaks of the profile of contact element  22 . 
   The contact element  22  made of profiled sheet metal can be easily and cost-effectively produced and simply cut to size. This ensures simple and therefore cost-effective production of inventive device  2 . 
   The profile of contact element  22  can be selected within wide limits.  FIGS. 9  to  11  show examples of different profiles. The profile of contact element  22  shown in  FIGS. 9 and 10  is substantially meander-like or wavy in cross section, while that depicted in  FIG. 11  is substantially zigzag-shaped. 
     FIGS. 9  to  11  indicate that the ends  32 ,  36  of contact element  22  are not provided with a profile to make it easier to insert ends  32 ,  36  into the pocket-like receptacles  30 ,  34 . If contact element  22  is made, for instance, from continuously profiled yard ware, the ends  32 ,  36  of contact element  22  can be flattened after it has been cut to size. 
     FIG. 12  shows a third exemplary embodiment of a device  2  according to the invention, which is distinguished from the embodiment shown in  FIG. 1  in that the retention means formed onto the elastic material  12  of main body  4  comprise a single part  86 . Part  86  is formed onto the inside of sealing lips  14 ,  16  in axial direction and is configured as a flat elastomer strip that extends from the longitudinal edge  27  of contact element  22  up to the opposite longitudinal edge  29  perpendicularly across contact element  22  and overlaps and thereby retains contact element  22  on its side facing away from main body  4 . As may be seen in  FIG. 12 , part  86  is arranged at a point remote from ends  32 ,  36  of contact element  22 .