Patent Publication Number: US-10770848-B2

Title: Connecting element

Description:
This application is a National Stage of International Application No. PCT/EP2017/066934 filed Jul. 6, 2017, claiming priority based on European Patent Application No. 16179977.0 filed Jul. 18, 2016. 
     TECHNICAL FIELD 
     The invention relates to a connection element for receiving a contact element to establish an electrical contact between two busbars as claimed in claim  1 . 
     PRIOR ART 
     Connection elements for the electrical connecting of two conductor elements such as two parallel running busbars are known from the prior art. 
     Many such contact elements are likewise known from the prior art. For example, one can mention here the corresponding products of the applicant. 
     Busbars are used for example in vehicles as fixed electrical conductor elements, which should then be electrically connected to busbars of other elements, such as an inverter module. Busbars may be used both in passenger cars, trucks, public transit vehicles, or electric bikes. With the use of hybrid motors, which are driven by fossil fuels and electric current, busbars are being used increasingly in passenger cars. Such busbars have also been used increasingly as contacts in connection with the propulsion of electric bikes. 
     Many connection solutions are known from the prior art for the connecting of busbars. For example, busbars are connected with the aid of screw fasteners, which must provide large pressing forces, since the contact points are only inadequately defined by a surface contacting. For this reason, it has become common to arrange a contact blade between the two busbars, which improves the electrical contact. 
     However, the prior art has the drawback that the connection by means of screws between the two busbars and the contact blade is very costly, which is undesirable in particular in the automotive industry, where short cycle times are required during manufacturing. 
     PRESENTATION OF THE INVENTION 
     Starting from the prior art, the problem which the invention proposes to solve is to indicate a connection element for the connecting of two busbars that overcomes the drawbacks of the prior art. Moreover, another preferred problem of the present invention is to indicate a connection element which can be produced easily and economically. 
     This problem is solved by the connection element of claim  1 . Accordingly, a connection element for establishing an electrical contact between two busbars comprises a housing with an interior and a contact element, which is mounted in the interior. Each of the two busbars can be inserted into the housing along an inserting direction. The contact element divides the interior along the plane into at least one first receiving space to receive a first busbar and a second receiving space to receive a second busbar. The contact element establishes an electrical contact between the first busbar and the second busbar. The contact element is mounted by several bearing points in the interior of the housing. At least one of the bearing points protrudes from a side wall into the interior, the side wall lying in a transverse plane oriented transversely to the plane, and the bearing point for the contact element providing a movement limitation in at least one translatory direction. 
     Such an arrangement of the bearing point yields the advantage that the other walls of the housing remain largely nonweakened, because no bearing points protrude from them. Furthermore, it produces the advantage that the two receiving spaces are blocked with the fewest possible bearing points, which might interfere with the inserting process of the busbars. Moreover, it produces the advantage that the stamping process becomes easier, which makes the manufacture more cost-favorable. 
     Thanks to the partitioning of the interior with the contact element, a structure can be created in which the respective busbars can be introduced properly and easily. 
     Preferably, said translatory direction runs substantially at right angles to said plane. That is, the movement limitation for the contact element occurs toward the plane and away from the plane. This is advantageous for the loading of the bearing point, since it can have a more robust construction thanks to its protruding from the side wall which is oriented in the transverse plane. Hence, for example, the number of inserting cycles can be increased. 
     Especially preferably, all bearing points providing a movement limitation in said translatory direction at right angles to said plane protrude from said side wall, oriented in said transverse plane. 
     By the term “busbar” is meant a rigid contact element with preferably a substantially rectangular cross section. The size of the cross section and also the length of the busbar is of no significance to the use of the connection element. 
     By the term “movement limitation” is meant that the bearing points provide an end stop which limits the movement of the contact element in the corresponding direction. The limitation may be such that no movement of the contact element is allowed, or such that a play is created, within which the contact element can move. Preferably, the contact element is mounted floating, i.e., with play, in said bearing point. 
     Preferably, one of said bearing points is a double bearing point, which starting from a middle position of the contact element provides a movement limitation for the contact element in two oppositely running translatory directions. 
     Said double bearing point, standing alone, thus provides a movement limitation in two oppositely running translatory directions. That is, with a single bearing point the movement of the contact element connected to the bearing point can be limited in two translatory directions. 
     By the formation of at least one double bearing point, providing the corresponding movement limitation, a corresponding bearing system can be achieved very easily, by a double bearing point. That is, the double bearing point takes on the function of a bearing system in two degrees of freedom, representing an advantageous double function. 
     The double bearing point furthermore has the advantage in manufacture, as well as in operation, if a single bearing point provides said movement limitation. In this way, two different elements do not have to be oriented to each other. 
     By the term “two oppositely running translatory directions” is meant that the two translatory directions run in directions running opposite to each other. Thus, the bearing points provide a movement limitation starting from a middle position of the contact element in the positive as well as the negative translatory direction, the positive and the negative translatory direction running in the same axial direction, yet opposite to each other. 
     Alternatively or additionally, one of the mentioned bearing points is a single bearing point, which starting from a middle position of the contact element provides a movement limitation for the contact element in one translatory direction. 
     Both double bearing points and single bearing points or solely double bearing points or solely single bearing points may be arranged on the same housing. 
     In a first embodiment, at least three, preferably four double bearing points are arranged. Two double bearing points protrude from the same side into the interior. One double bearing point or two double bearing points protrude from a side wall situated opposite said side wall into the interior. 
     Preferably, all double bearing points in the first embodiment are similar to each other, specifically in that starting from a middle position of the contact element they provide a movement limitation for the contact element in two oppositely running translatory directions. 
     In a second embodiment, at least one double bearing point and at least two single bearing points are present. From a first side wall at least one double bearing point protrudes into the interior. From a side wall situated opposite the first side wall, at least two single bearing points protrude into the interior. One of the two single bearing points limits the movement in one of the translatory directions and the other of the two single bearing points limits the movement in the opposite translatory direction. 
     In a third embodiment, four single bearing points are present. From a first side wall at least two single bearing points protrude into the interior, wherein one of the two single bearing points limits the movement in one of the translatory directions and wherein the other of the two single bearing points limits the movement in the opposite translatory direction. From a side wall situated opposite the first side wall at least two single bearing points protrude into the interior, wherein one of the two single bearing points limits the movement in one of the translatory directions and wherein the other of the two single bearing points limits the movement in the opposite translatory direction. 
     Preferably, in all embodiments two bearing points are situated opposite each other with respect to the interior, wherein these two oppositely situated bearing points starting from a middle position of the contact element provide a movement limitation for the contact element in two oppositely running second translatory directions, the second translatory direction running substantially transversely to the inserting direction and parallel to the plane. That is, the bearing points provide a movement limitation for the contact element with respect to the first translatory direction, which is oriented preferably substantially at right angles to the plane, and with respect to the second translatory direction, which is oriented substantially transversely to the longitudinal axis or to the inserting direction and parallel to the plane. 
     The two groups of bearing points in the case of double bearing points are arranged such that they together provide the movement limitation in the corresponding first and second directions. With respect to the direction transversely to the longitudinal axis, the one group provides a movement limitation from a starting position in the positive direction and the opposite negative direction. 
     Preferably, the double bearing point has a slot to receive parts of a carrier strip of the contact element. In particular, edge regions of the contact element, especially those of the carrier strip or the entire carrier strip, protrude into the slot of the bearing point and are supported there accordingly. 
     The slot in this case provides the movement limitation in both directions. 
     Preferably, the slot in one direction at right angles to said plane is configured broader than the thickness of the contact element, especially that of the carrier strip, such that a play is provided between the slot and the contact element. That is, the contact element is supported with play in the slot in the direction of the second direction. The slot provides the movement limitation, as mentioned, and the contact element can be moved within this movement limitation in the bounds of said play. 
     The single bearing point is preferably provided by a bearing surface. The contact element lies against the bearing surface. 
     Preferably, the slots or the bearing surfaces within one group of bearing points are offset from each other with respect to the plane. Thanks to the offset arrangement, the contact element can lie with a slight tilt in the interior, which makes the inserting process of the busbars easier. 
     Especially preferably, the slots or bearing surfaces are arranged such that the slots or bearing surfaces lying closer to an entrance opening, looking in the inserting direction, are situated at a greater distance from the wall coming into contact with the busbar than the slots or bearing surfaces lying further away from the entrance opening. 
     Preferably, the bearing points in all embodiments are webs bent out from the housing and protruding into the interior, the webs protruding from one side wall of the housing. The webs stand in connection with the housing as a single piece and are plastically deformed so that the webs are placed in their position. 
     Especially preferably, the slot is arranged at the free end of the web and extends into the web at an end face closing off the free end. The slot is open in the end face. That is, the contact element can be inserted via the end face into the slot. The bearing surface is likewise preferably arranged at the free end of the web. 
     Preferably, the webs are inclined at an angle relative to the longitudinal axis, the angle being between 10° and 170°, especially between 30° and 150°. 
     Preferably, the contact element is mounted floating in the interior in two third translatory directions running opposite to each other, extending parallel to the inserting direction, so that the contact element can move in this third translatory direction within certain limits, limits being provided by an end stop. 
     Preferably, the housing is provided by a wall, two side walls formed at opposite edges from the wall and protruding substantially perpendicular from the wall, and by side edges formed on the side walls. 
     Preferably the bearing points or the webs, as described above, are molded as a single piece on the housing and protrude from the side walls into the interior, the bearing points being preferably bent out from the side walls. 
     Preferably the housing has one or more installation openings, which are preferably arranged such that access to the carrier strips for a tool can be created. 
     The one or more installation openings reach through the housing such that a tool can engage from the outside into the interior. 
     Preferably the contact element, especially the carrier strip, has one or more installation openings, in which a tool can engage. Thanks to this engagement, the contact element can be placed in the interior. 
     Preferably the housing is fabricated from a metallic material and preferably by a punching and forming process. The housing is preferably a single piece. 
     Further optional features or advantages shall be described below. 
     Preferably the resilient contact web exerts a restoring force against the respective busbar when it establishes the electrical contact between the busbars. This creates a durable and defined electrical contact. 
     Preferably the contact element is arranged such that it comes to lie between the first busbar and the second busbar when the busbars protrude into the respective receiving space. 
     The contact element is preferably mounted floating in the interior, so that it is movable or displaceable perpendicular to the plane toward the first receiving space or toward the second receiving space within defined limits, which are provided by the bearing point or the bearing points. Defined limits can mean, for example, the equalizing of tolerances. The floating mount has the advantage that tolerances are automatically evened out. 
     The contact element may have various designs. It is important that the contact element has resilient contact points, so that a durable contact can be produced between the busbars. 
     In one especially preferred variant, the contact element is configured as follows. The contact element comprises two carrier strips running parallel to each other and in the direction of a longitudinal axis and at least one resilient contact web, which connects the two carrier strips. The carrier strips define a substantially flat plane, which divides the interior into the two receiving spaces. 
     The especially preferred contact element comprises preferably a plurality of contact webs, which stand in connection with at least one carrier strip, situated in the plane, while the contact webs stand in connection with the at least one carrier strip such that they are movable in resilient manner with respect to the strip, especially rotatable or swivelable. Preferably, the contact webs lie at an angle to the plane, the contact element being situated in the interior such that the angle during the inserting of the busbar into the respective receiving space becomes smaller, while the contact webs preferably lie parallel to each other. Furthermore, the contact webs extend, looking from the plane, on both sides of the plane and protrude beyond the respective side of the plane. Preferably, the contact webs stand in connection with the at least one carrier strip by torsion spring joints. 
     One preferred modification of the connection element is characterized in that the two receiving spaces each have at least one entrance opening, through which the respective busbar protrudes into the corresponding receiving space, the first receiving space being accessible through a first entrance opening from a first side and the second receiving space through a second entrance opening from a second side, the first side being preferably situated opposite the second side. 
     Another preferred modification of the connection element is characterized in that each receiving space has at least one end stop element, which is situated at a spacing from the contact element in a direction perpendicular to the plane of the contact element, the respective busbar lying against the end stop element, and a force from the contact element pressing the busbar against the respective end stop element being produced by the resilient contact webs. 
     Preferably, the end stop element has the shape of said wall or said side edge. 
     A further preferred modification of the connection element is characterized in that the housing furthermore has at least one end stop element for busbars, the at least one end stop element protruding into the entrance opening such that the busbar not through the respective entrance opening comes up against the end stop element. 
     A further preferred modification of the connection element is characterized in that the housing has guide elements in the area of the entrance openings, making it easier to insert the busbars. 
     A further preferred modification of the connection element is characterized in that the distance between contact element and housing in the first receiving space is equal to the distance between contact element and housing in the second receiving space, or in that the distance between contact element and housing in the first receiving space is less than or greater than the distance between contact element and housing in the second receiving space. 
     One layout comprises a connection element as described above, a first busbar and a second busbar arranged in parallel with the first busbar, wherein the first busbar protrudes into the first receiving space and the second busbar into the second receiving space, and between the two busbars an electrical contact is established by the contact element arranged between the first receiving space and the second receiving space. 
     Further embodiments are indicated in the dependent claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Preferred embodiments of the invention shall be described below with the aid of drawings, serving only as an explanation and not to be interpreted in limiting fashion. The drawings show: 
         FIG. 1 , a perspective view of a connection element according to one embodiment of the present invention without busbars, seen from above; 
         FIG. 2 , a perspective view of the connection element of  FIG. 1 , seen from below; 
         FIG. 3 , a sectional representation of the connection element of  FIG. 1 , without busbars; 
         FIG. 4 , a sectional representation of the connection element of  FIG. 1 , with busbars; 
         FIG. 5 a   , a partial sectional representation through the connection element of  FIG. 1 , with a bearing point configured as a double bearing point; 
         FIG. 5 b   , a partial sectional representation through the connection element of  FIG. 1 , with a bearing point configured as a single bearing point; 
         FIG. 6 , a perspective view of the connection element of  FIG. 1  with busbars not yet inserted; 
         FIG. 7 , the view per  FIG. 6  with busbars inserted; 
         FIG. 8 , a perspective view of another embodiment of the present invention; and 
         FIG. 9 , a further perspective view of  FIG. 8 . 
     
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
       FIGS. 1 and 2  show a connection element  1  with which an electrical contact can be established between two busbars. The connection element basically comprises a housing  2  and a contact element  3  arranged in the housing  2 , by which the electrical contact can be produced between the busbars. 
       FIGS. 3 and 4  show the cross section of the connection element  1 . The housing  2  basically comprises an interior  20  accessible from the outside, which is divided by the contact element  3  into a first receiving space  21  and a second receiving space  22 . The interior  20  is bounded by a wall  240 , two side walls  242  formed at opposite edges from the wall  240  and protruding substantially perpendicular from the wall  240 , and side edges  241  formed on the side walls  242 . In other words, it may also be said that the wall  240 , the side walls  242  and the side edges  241  provide a tunnel-shaped interior  20 , which is accessible through openings  28 ,  29  situated opposite each other. The tunnel-shaped interior  20  may also be completely enclosed by an encircling side wall, and then the side edges  241  are likewise formed as a wall or stand in connection with each other, and the openings  28 ,  29  likewise afford access to the interior. The wall  240  and the side edges  241  each extend in a flat plane and are spaced apart from each other, the spacing defining the clear width L of the interior. Preferably the interior is cuboidal. 
     The two receiving spaces  21 ,  22  basically serve for receiving the respective busbars  4 ,  5 . The first receiving space  21  is accessible through a first entrance opening  28  and the second receiving space  22  through a second entrance opening  29 . The busbars  4 ,  5  are led into the respective receiving space through these entrance openings  28 ,  29 . 
     The contact element  3  lies in a plane or defines a plane  39  which extends at least partly through the interior  20 . The plane  39  preferably lies in the middle between the two busbars and extends parallel or substantially parallel or slightly at an angle to them. In other words, the plane  39  extends preferably through the middle of the contact element  3 . 
     The contact element  3  shown in the figures is one possible example of an especially preferred contact element. But it is also conceivable to use other contact elements, which likewise extend in a plane and comprises resilient contact areas. 
     The mounting of the contact element in the interior shall now be explained more closely with the aid of  FIG. 3 to 5 . 
     The contact element  3  is held in the interior  20  by bearing points  23 . The bearing points  23  are preferably formed as a single piece with the housing and protrude into the interior  20 . In the embodiment shown, double bearing points are depicted. 
     In the embodiment shown, the bearing points  23  are configured such that, starting from a middle position of the contact element  3 , they provide a movement limitation for the contact element  3  in two oppositely running translatory directions R 1 , R 1 ′. That is, the contact element  3  is mounted in the bearing points  23  such that it is held within the movement limitation either fixed or within a play provided by the bearing point  23 . 
     Thanks to such a configuration, the contact element  3  is mounted in the bearing point  23  in two oppositely running directions. 
     The translatory directions R 1 , R 1 ′ run opposite each other and in the present case substantially at right angles to the plane  39 . 
     In the present embodiment, two times two bearing points  23  are arranged opposite each other with respect to the interior, these two oppositely arranged bearing points  23  starting from a middle position of the contact element  3  providing a movement limitation for the contact element in two oppositely running second translatory directions R 2 , R 2 ′. The second translatory direction R 2 , R 2 ′ runs substantially transversely to the inserting direction and parallel to the plane  39 . 
     Regarding the number of bearing points  23 , a total of four bearing points  23  are present here, each time a group of two bearing points  23  protruding from the same side into the interior  20 . Two groups of two bearing points  23  each are situated opposite each other with respect to the interior  20 . 
     The bearing point  23  in the embodiment shown has a slot  230 , which is designed to receive parts of the carrier strip  31 . It can be well seen in  FIG. 5 a    how an edge region of the carrier strip  31  protrudes into the slot  230 . 
       FIG. 5 b    shows an alternative variant of the bearing point, the alternative variant of the bearing point comprising a bearing surface  236 , which provides the movement limitation. 
     In the variant shown, the slot  230  in one direction at right angles to said plane is configured broader than the thickness of the carrier strip. The width is such that a play is produced between the slot and the carrier strip. That is, the carrier strip  31  and thus also the contact element  3  as such can move within the play in the slot  230 . The play has the advantage that the contact element  3  is forced slightly away from the first busbar as it is inserted and once again forced toward the first busbar when the other busbar is inserted. This has the advantage that tolerances in the thickness of the busbars  4 ,  5  or in the clear width of the receiving spaces can be evened out, and it can thereby be ensured that the contact element  3  always lies in the middle between the two busbars  4 ,  5  during the contacting process. 
     Alternatively, the slot  230  could also have the same thickness as the carrier strip  31 , so that no play is produced. 
     It can be well seen in  FIG. 3  that the slots  230  are offset from each other relative to the plane  39  within one group of bearing points  23 . The left-hand slot  230  here is higher than the right-hand slot  230 . 
     Preferably, the slots  230  lying closer to the entrance opening  28 ,  29 , looking in the inserting direction E 1 , E 2 , are situated at a greater distance A 1 , A 2  from the wall  240  coming into contact with the busbar  4 ,  5  than the slots further away from the entrance opening  28 ,  29 . Such an arrangement makes it easier to insert the busbars  4 ,  5 , because the contact element lies at a slight inclination in the interior  20 . 
     The bearing points  23  here are fashioned as webs, which are bent into the interior  20 . In the present embodiment, the bearing points  23  are provided as parts of the side wall  242  and protrude out from the side wall  242 . 
     Said slot  230  is arranged at the free end  231  of the web and extends into the web at an end face  232  closing off the free end  231 . The slot is open in the end face  232 . 
     The webs are inclined at an angle to the longitudinal axis L, the angle being between 10° and 170°, especially 30° to 150°. 
     Moreover, the contact element  3  is mounted floating in the interior  20  in two third translatory directions R 3 , R 3 ′ running opposite to each other, extending parallel to the inserting direction E 1 , E 2  or to the longitudinal direction L, so that the contact element  3  can move in this third translatory direction R 3 , R 3 ′ within defined limits, the limits being provided by an end stop  234 . The end stop  234  in the embodiment shown is provided by the inserting aid  281  and  291 . 
     The housing  2 , as is shown in particular in  FIGS. 2 and 5 , has several installation openings  233 , which are preferably arranged such that access to the carrier strips  31  for a tool can be created. Moreover, the carrier strip  31  also preferably has installation openings planar in which a tool can engage. The installation openings  235  are shown in  FIG. 5 . 
       FIGS. 4, 6 and 7  show the connection element  1 , which stands or comes into connection with a first busbar  4  and a second busbar  5 . The two busbars  4 ,  5  here have a rectangular cross section and extend along a longitudinal axis A 1  and A 2 . In the present embodiment, the respective longitudinal axes A 1  and A 2  run in parallel and are offset from each other. Furthermore, the axes A 1  and A 2  are situated parallel to the aforementioned plane  39 . The busbars may have identical dimensions to each other, or they may have different thicknesses or widths. Each of the two busbars has an end face  40 ,  50 , two side walls  41 ,  51 , a contact surface  42 ,  52  facing the contact element  3 , and a surface  43 ,  53  facing the housing  2 . The contact surfaces  42 ,  52  here are fashioned as stepped surfaces. 
     The contact element  3  in the present embodiments is represented as a contact blade, having two carrier strips  31  extending along a longitudinal axis and a plurality of consecutively arranged contact webs  32 . The contact webs  32  stand in connection with the carrier strips  31  on both sides. The carrier strips  31  substantially define the aforementioned plane  39 . The contact webs  32  are resilient, in the present case due to a torsional segment in the area of the connection to the carrier strip  31 . The torsional segment may be called a torsion spring joint  34 , for example. The contact element  3  may also have a different configuration. In other embodiments, the contact element  3  should have resilient elements which can apply a spring force perpendicular to the carrier strip  31  or to the longitudinal direction A or to the plane  39 , so that the two busbars are pressed away from each other by the resilient elements against a respective end stop, as shall be described below. However, it should be ensured that the contact webs  32  always stand in connection with both busbars  4 ,  5 , so that a plurality of defined contact points can be provided. 
     The two busbars  4 ,  5  extend, at least in the region in which they protrude into the housing  2 , parallel to and offset from each other, so that a gap is created between the two busbars, in which the contact element  3  can come to rest. That is, the contact surfaces  42 ,  52  run substantially parallel to the plane  39 . The contact surfaces  42 ,  52  of the busbars  4 ,  5  stand in connection with the contact webs  32 , that is, the contact webs  32  rest against both the contact surface  42  of the first busbar  4  and the contact surface  52  of the second busbar  5  and thus establish the electrical contact between the two busbars  4 ,  5 . 
     By the term busbar is meant any element extending along a central axis and conducting electric current. Such busbars are used, for example, to carry energy in vehicles, such as hybrid passenger cars, or public transit vehicles. In this case, currents in the range of 100 to 1000 Amperes are carried. Lower currents are also conceivable, especially in the field of electric bikes. 
     By the term resilient is meant the action of a spring force or a restoring force. The restoring force acts on the contact web when it is moved from its original position into a working position or contact position. That is, the restoring force acts during a contacting between the contact webs and the busbars. 
     Since the contact element  3  comes to lie in the middle between the two busbars  4  and  5 , it may also be said that the carrier strips  31  lie in the plane  39  or define this plane  39 . The contact webs  32  extend, looking from the plane  39  or from the carrier strip  31 , both above the plane  39  and below the plane  39 . This means, in other words, that the contact webs  32  at least in the noncontacting condition extend or stick out on both sides of the plane  39  or the carrier strip  31 . 
     The contact webs  32  stand at an angle α to the plane  39  or to the carrier strip  31 . Preferably, the angle α is between 20° and 70°, especially preferably between 30° and 60°. Preferably, all contact webs  32  stand at the same angle to the carrier strip. That is, all contact webs  32  run parallel to each other at least in the noncontacting condition. 
     The contact element  2 , is made from a material conducting electric current, such as a spring bronze or a copper alloy. 
       FIG. 4  shows a sectional representation of the connection element  1  with inserted busbars  4 ,  5  and  FIG. 3  shows a sectional representation of the connection element  1  without busbars. 
     Each of the receiving spaces  21 ,  22  of the housing has at least one end stop element  24 , which is arranged at a spacing from the contact element  3  in a direction perpendicular to the plane  39 . The respective busbar lies against the end stop element  24 , which are forced away from the contact element  3  by a force provided by the resilient contact webs  32 . In this way, the respective busbar is pressed against the corresponding end stop element  24 . 
     In the embodiment shown in the figures, the end stop element  24  on the one hand has the shape of a wall  240  and on the other hand the shape of a side edge  241 . The wall  240  serves as an end stop element for the second busbar  5  and the two side edges  241  serve as an end stop element for the first busbar  4 . 
     The wall  240  may also be called a housing wall, while two side walls  242  stand away from the wall substantially perpendicular to two opposite edges, one side edge  241  being formed respectively at the free end of the side wall  242 . 
     Each of the two receiving spaces  21 ,  22  has a clear width L 1 , L 2 , which is less than the thickness of the respective busbar  4 ,  5 . The clear width is defined as the distance between the upper edge  33  or lower edge  35  of the contact web  32  and the end stop element  24 . By the choice of the smaller clear width, the spring action of the contact webs  32  when making the connection can be ensured. The clear width is accordingly defined in terms of the thickness of the busbar being inserted. 
     When the first busbar  4  is inserted, the contact element  3  is slightly lifted on account of the floating mount, while the contact webs  32  are not yet deflected, or only slightly so. Then, if the second busbar  5  is inserted, the contact webs  32  are rotated, since the busbar  5  rotates each of the contact webs by the upper edge  33 . The rotation occurs at the torsion spring joints  34  of the contact blade or the contact element  3 . Thanks to the arrangement of the torsion spring joint  34 , a constant force acts on the first busbar  4  and the second busbar  5  as described above, since the contact blades due to the prestressing force from the torsion spring joints  34  strive to return to their original position. In other words, the first busbar  4  is pressed by a force provided by the torsion spring joints  34  against the end stop  24  when the second busbar  5  is inserted. 
     But depending on the dimension it is also possible for the contact webs  32  to be rotated upon inserting of the first busbar  4 , since the busbar  4  displaces each of the contact webs by the lower edge  35 . 
     When the second busbar  5  is inserted, if the first busbar  4  is already present in the first receiving space  21 , the second busbar  5  thus contacts the contact webs  32  across the upper edge  33 . The dimension of the busbars  4 ,  5  is chosen such that a force provided by the torsion spring joints  34  is always acting on both busbars  4 ,  5  and forces them to the outside, i.e., against the end stop elements  24 . 
     Regardless of the designation of the two busbars, it is also possible for the second busbar  5  to be inserted before the first busbar  4 , and the above described processes will equally apply. 
     The contact element  3  here is arranged in the interior such that, when the busbars are inserted, the angle α between the contact webs  32  and the carrier strip decreases. The contact webs  32  are situated with respect to the busbar such that the busbar presses the respective contact web  32  by a swivel movement toward the carrier strip  31  or the plane  39 . During the inserting process, the busbar  4 ,  5  contacts, by the edge formed by the end face  40  and the contact surface  42 , the surface of the contact web  32  facing the edge and then forces it against the carrier strip, whereupon the contact web  32  rests against the contact surface  42  by the corresponding upper edge  33  or lower edge  35 . 
     In other words, it may also be said that the two busbars  4 ,  5  are forced away from each other by the torsion spring joints  34  and the contact webs  32 , the busbars  4 ,  5  resting against the respective end stop elements  24 . The dimensions of the busbars  4 ,  5 , the receiving spaces  21 ,  22  and the contact element  3  are chosen such that a force acts from the contact element  3  on the busbars  4 ,  5  substantially at all times. This is accomplished in that the distance between the two busbars in the condition positioned in the housing is less than the distance between the upper edge  33  and the lower edge  35  of the contact webs, looking perpendicular to the busbars. 
     Thanks to the stability of the housing  2 , this force remains constant during the entire period of use, which is of great benefit in regard to the defined contacting between contact webs  32  and the respective contact surface  42 ,  52  of the busbars  4 ,  5 . A defined contacting is a precondition for a good and constant transfer of electric energy over the entire service life. 
     The respective receiving space is bounded by a corresponding boundary element  27  in the direction of the respective longitudinal axis A 1  or A 2 . The boundary element  27  extends from the respective end stop elements  24  substantially perpendicular or at an angle, so that the respective receiving space  21 ,  22  is bounded by the boundary element  27 . The boundary element  27  has basically two functions. On the one hand, the boundary elements  27  constitute an end stop for the busbars  4 ,  5 . 
     In the region of the entrance openings  28 ,  29 , moreover, inserting aids  280  and  290  may be provided. The two inserting aids  280 ,  290  stand at an angle to the longitudinal axis A, so that the clear width of the entrance openings  28 ,  29 , looking from the interior  20 , increases toward the end of the entrance opening  28 ,  29 , so that when the respective busbar is inserted the cross section, or the clear width, decreases continuously. Side inserting aids  281 ,  291  in the form of tabs may be arranged to the left and right of the interior  20 . 
     In the embodiment shown, the respective inserting aids  280 ,  281 ,  290 ,  291  stand in connection with the corresponding boundary element  27 . 
     Preferably, the housing  2  is made of a metallic material, so that the stability of the housing remains constant over the entire service life. The choice of a metallic material furthermore has the benefit that the heat from the contact region between the two busbars can be carried away. Accordingly, the housing also acts as a cooling element. The housing can be fabricated for example from a metal sheet by punching, bending and/or forming. 
     Yet suitable plastics can also be used, paying attention to the shape stability, since a deformation of the housing over time may have negative impact on the quality of the electrical contact. 
     The housing  2  serves not only for providing the end stop elements in the direction perpendicular to the plane, but also provides for the guidance and positioning of the two busbars. 
     Preferably, the connection is produced as follows. In a first step, the connection element is inserted via the first busbar  4 , so that this can protrude into the first receiving space  21 . The contact webs  32  are moved by a swivel movement from the original position. In a second step, the second busbar  5  can be shoved into the second receiving space, whereby the second busbar  5  likewise makes contact with the contact webs. 
     Alternatively, the reverse process is also possible for making the connection, wherein the connection element is at first shoved in by the second busbar  5 , so that this protrudes into the second receiving space  22 , and then the first busbar  4  is inserted into the first receiving space  21 . When the first busbar  4  is inserted, the contact webs  32  are then rotated or swiveled from the original position by a swivel movement, as described above. 
       FIGS. 8 and 9  show a further embodiment of the present invention. The same parts are given the same reference numbers, and reference is made to the above description. 
     In addition, the further embodiment comprises a positioning tab  300  protruding from the housing  2 . The positioning tab  300  serves as an element for positioning the housing  2  in a superordinate system, so that the housing  2  assumes the correct position. 
     Furthermore, the contact element  3  is inserted into the housing  2  by another method. In this way, the housing  2  and the contact element  3  have no installation openings. The contact element  3  is pulled into the interior  20  by means of a tool and then comes into contact with the already formed bearing points  23  in the interior  20 . The contact element is pulled in the direction R 3  or R 3 ′. 
     Once the contact element  3  is situated in the interior  20 , the end stops  234  and funnel tabs  237  formed on them are bent, so that the connection element  1  is likewise secured in the interior  20  against a movement in the direction R 3  or R 3 ′. The funnel tabs  237  are optional, that is, these may also be absent from the second embodiment. 
     LIST OF REFERENCE NUMBERS 
     
         
           1  connection element 
           2  housing 
           3  contact element 
           4  first busbar 
           5  second busbar 
           20  interior 
           21  first receiving space 
           22  second receiving space 
           23  bearing points 
           24  end stop element 
           27  boundary element 
           28  first entrance opening 
           29  second entrance opening 
           31  carrier strip 
           32  contact webs 
           33  upper edge 
           34  torsion spring joint 
           35  lower edge 
           39  plane 
           40  end face 
           41  side walls 
           42  contact surface 
           43  surface 
           50  end face 
           51  side walls 
           52  contact surface 
           53  surface 
           230  slot 
           231  free end 
           232  end face 
           233  installation openings 
           234  end stop 
           235  installation openings 
           236  bearing surface 
           237  funnel tabs 
           240  wall 
           241  side edge 
           242  side wall 
           280  inserting aids 
           290  inserting aids 
           281  side inserting aids 
           291  side inserting aids 
           300  positioning tab 
         L clear width of interior 
         L 1  clear width of first receiving space 
         L 2  clear width of second receiving space 
         E 1  inserting direction 
         E 2  inserting direction