Patent Publication Number: US-11031715-B2

Title: Connection terminal having a reduced size

Description:
CROSS-REFERENCE TO PRIOR APPLICATIONS 
     This application is a U.S. National Phase application under 35 U.S.C. § 371 of International Application No. PCT/EP2017/062973, filed on May 30, 2017, and claims benefit to Luxembourg Patent Application No. LU93095, filed on Jun. 1, 2016. The International Application was published in German on Dec. 7, 2017 as WO 2017/207530 under PCT Article 21(2). 
     FIELD 
     The invention relates to a connection terminal for connecting at least one electrical conductor, comprising a housing, a first connection space formed in the housing, a second connection space formed in the housing, a first busbar piece arranged in the first connection space, a second busbar piece arranged in the second connection space, a first torsion spring which is arranged in the first connection space and has a clamping limb and a retaining limb, and a second torsion spring which is arranged in the second connection space and has a clamping limb and a retaining limb. 
     BACKGROUND 
     From DE 10 2008 014 177 A1, for example, a connection terminal in the form of a series terminal is known which has two connection spaces, in each of which a torsion spring is arranged for clamping a conductor to be connected against a busbar piece. The connection spaces are arranged so as to be spaced apart from one another, and therefore the length of the entire connection terminal is relatively large. 
     SUMMARY 
     In an embodiment, the present invention provides a connection terminal for connecting at least one electrical conductor, comprising: a housing; a first connection space formed in the housing; a second connection space formed in the housing; a first busbar piece arranged in the first connection space; a second busbar piece arranged in the second connection space; a first torsion spring which is arranged in the first connection space and has a clamping limb and a retaining limb; and a second torsion spring which is arranged in the second connection space and has a clamping limb and a retaining limb, wherein the first connection space and the second connection space adjoin one another, and wherein the first torsion spring is arranged in the first connection space and the second torsion spring is arranged in the second connection space such that the retaining limb of the first torsion spring is supported by the retaining limb of the second torsion spring. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention will be described in even greater detail below based on the exemplary figures. The invention is not limited to the exemplary embodiments. Other features and advantages of various embodiments of the present invention will become apparent by reading the following detailed description with reference to the attached drawings which illustrate the following: 
         FIG. 1  is a schematic view of a connection terminal according to an embodiment of the invention, and 
         FIG. 2  is a schematic view of a detail of the connection terminal shown in  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION 
     An aspect of the present invention provides a connection terminal which is characterized by a reduced size. 
     The connection terminal according to the invention is characterized in that the first connection space and the second connection space adjoin one another, and in that the first torsion spring is arranged in the first connection space and the second torsion spring is arranged in the second connection space in such a way that the retaining limb of the first torsion spring is supported by the retaining limb of the second torsion spring. 
     The two connection spaces adjoining one another makes it possible for the length of the connection terminal to be reduced, as a result of which the whole connection terminal can be made much more compact. In this case, the connection spaces adjoin one another in such a way that they merge into one another. In this case, the connection spaces can be designed to be open with respect to one another at least in regions or in portions. This makes it possible for the first torsion spring arranged in the first connection space and the second torsion spring arranged in the second connection space to be arranged directly next to one another or adjacent to one another. In this case, the two torsion springs are arranged with respect to one another in such a way that they are supported against one another by the retaining limb of the first torsion spring being supported by the retaining limb of the second torsion spring. Thus, in the solution according to the invention, the torsion springs are not supported, as is otherwise conventional, by their retaining limbs on a wall of the housing or a tab bent out of a busbar piece, but on the contrary, they are mounted against one another and thus support one another. This makes it possible to achieve an even more compact design of the entire connection terminal. The torsion springs supporting one another allows said springs to mutually absorb their reaction forces, so that the force of the first torsion spring can act on the second torsion spring and the force of the second torsion spring can act on the first torsion spring. In this case, the two torsion springs are designed to be separate from one another such that the two torsion springs are provided as two individual parts. The torsion springs are thus not rigidly coupled to one another, but the torsion springs are, in particular in the region of their retaining limbs, movable relative to one another. This mobility of the torsion springs relative to one another allows for optimized force distribution and force absorption to be achieved between the two torsion springs. 
     In order for the retaining limb of the first torsion spring to be supported by the retaining limb of the second torsion spring, it is preferably provided that an edge region of a free end of the first torsion spring abuts an edge region of a free end of the second torsion spring. The two torsion springs thus abut one another preferably only at a very small region, as a result of which compensation between the reaction forces of the two torsion springs can be increased, however. In this case, the retaining limbs of the two torsion springs are preferably arranged with respect to one another at an angle of 2°≤α≤15°, preferably at an angle of 5°≤α≤10°. The retaining limbs of the torsion springs thus preferably do not abut one another flatly, but in a punctiform manner. The retaining limbs of the torsion springs are thus preferably positioned so as to be set against one another. 
     In order to be able to increase the stability of the positioning of the torsion springs in the housing, it is preferably provided that a receiving space is formed in the housing, into which space the retaining limb of the first torsion spring and the retaining limb of the second torsion spring can protrude. The receiving space is preferably formed by a contour which is molded, in particular embossed, into the wall of the housing. The receiving space is preferably formed in the region of the free ends of the retaining limbs of the torsion springs so that the receiving space can surround the free ends of the retaining limbs. The receiving space can thus limit the freedom of movement of the retaining limbs in the longitudinal direction of the connection terminal and thus vertically with respect to the longitudinal direction of the retaining limbs, as a result of which a stabilizing effect can be achieved on the retaining limbs and thus on the two torsion springs. If for example a conductor is inserted and connected only in one of the two connection spaces, or for example conductors having different cross sections are inserted and connected in the two connection spaces, the receiving space or a wall of the receiving space can serve as a kind of stop for the more strongly deflected or loaded torsion spring. This makes it possible to limit the freedom of movement of the more heavily loaded torsion spring, as result of which it can be achieved that the forces on the connected conductor can drop as little as possible or not at all, and the conductor can be safely connected as result. 
     The receiving space is preferably trough-shaped. Due to the trough-shaped design, the receiving space can surround the free ends of the retaining limbs substantially in a U-shape. 
     In order to be able to further reduce the installation space of the connection terminal and also in order to be able to reduce the number of parts to be mounted in the connection terminal, the first busbar piece and the second busbar piece can be formed integrally with one another. The two connection spaces can then also be designed to be open with respect to one another in the region of the busbar pieces. 
       FIG. 1  shows a connection terminal  100  for connecting electrical conductors. The connection terminal  100  shown here is designed as a series terminal which can be snapped onto a support rail. 
     The connection terminal  100  has a housing  10 , in particular made of a plastics material, in which a first connection space  11  for connecting a first conductor and a second connection space  12  for connecting a second conductor are formed. The two connection spaces  11 ,  12  are arranged directly adjacent to one another, and thus adjoin one another. The two connection spaces  11 ,  12  are designed to be open with respect to one another, in regions, such that the connection spaces  11 ,  12  merge into one another 
     In order to insert a first conductor into the first connection space  11 , the housing  10  has a first conductor inserting opening  13 . In order to insert a second conductor into the second connection space  12 , the housing  10  has a second conductor inserting opening  14 . 
     A first busbar piece  15  is arranged in the first connection space  11 , and a second busbar piece  16  is arranged in the second connection space  12 , the first busbar piece  15  and the second busbar piece  16  being integral. 
     Further, a first torsion spring  17  is arranged in the first connection space  11  for connecting and clamping a conductor inserted into the first connection space  11  against the first busbar piece  15 . 
     A second torsion spring  18  is arranged in a second connection space  12  for connecting and clamping a conductor inserted into the second connection space  12  against the second busbar piece  16 . The first torsion spring  17  has a clamping limb  19  for clamping an inserted conductor against the first busbar piece  15 , and a retaining limb  20 , the clamping limb  19  and the retaining limb  20  being integrally connected to one another by means of an arcuate portion  21 . The second torsion spring  18  also has a clamping limb  22  for clamping an inserted conductor against the second busbar piece  16 , and a retaining limb  23 , the clamping limb  22  and the retaining limb  23  being integrally connected to one another by means of an arcuate portion  31 . 
     The two torsion springs  17 ,  18  are arranged mirror-symmetrically to one another, so that the retaining limbs  20 ,  23  of the two torsion springs  17 ,  18  are arranged opposite or directly adjacent to one another. On the other hand, the clamping limbs  19 ,  22  of the torsion springs  17 ,  18  are directed away from one another. 
     In this case, the retaining limbs  20 ,  23  of the torsion springs  17 ,  18  are arranged adjacent to one another in such a way that the retaining limb  20  of the first torsion spring  17  is supported by the retaining limb  23  of the second torsion spring  18 . This can also be seen in particular in the detail in  FIG. 2 . 
     The retaining limbs  20 ,  23  support one another at a free end  25 ,  27  of the two retaining limbs  20 ,  23 , the free ends  25 ,  27  being remote from the arcuate portions  21 ,  31  of the torsion springs  17 ,  18 . The retaining limbs  20 ,  23  thus do not support one another over the entire length of the retaining limbs  20 ,  23 , but only at a small portion of the retaining limbs  20 ,  23 . The two retaining limbs  20 ,  23  do not abut one another flatly, but the abutment is substantially punctiform in that an edge region  24  of the free end  25  of the retaining limb  20  of the first torsion spring  17  abuts an edge region  26  of a free end  27  of the retaining limb  23  of the second torsion spring  18 . The retaining limbs  20 ,  23  of the two torsion springs  17 ,  18  are arranged with respect to one another at an angle of 2°≤α≤15°, so that the two retaining limbs  20 ,  23  are positioned so as to be set against one another. The edge regions  24 ,  26 , at which the retaining limbs  20 ,  23  abut one another, extend transversely to the longitudinal direction or longitudinal extension of the retaining limbs  20 ,  23 . 
     To increase the stability of the two abutting retaining limbs  20 ,  23  of the torsion springs  17 ,  18 , a receiving space  28  is formed in the housing  10 , into which space the two retaining limbs  20 ,  23  protrude by their free ends  25 ,  27 . The receiving space  28  is formed by a contour that is molded or embossed into the housing  10  and that protrudes from a rear wall  29  of the housing  10  into an inner space of the housing  10 . The receiving space  28  has a wall  30  which, in its width, corresponds approximately to the width of the retaining limbs  20 ,  23  of the torsion springs  17 ,  18 . The wall  30  and thus the receiving space  28  are substantially U-shaped, so that the receiving space  28  surrounds the free ends  25 ,  27  of the retaining limbs  20 ,  23 . When the retaining limbs  20 ,  23  are deflected, the wall  30  of the receiving space  28  can thus serve as a kind of stop or stop surface in order to be able to limit the movement of the retaining limbs  20 ,  23  transversely to their longitudinal extension. The receiving space  28  has a trough-shaped design. 
     While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive. It will be understood that changes and modifications may be made by those of ordinary skill within the scope of the following claims. In particular, the present invention covers further embodiments with any combination of features from different embodiments described above and below. Additionally, statements made herein characterizing the invention refer to an embodiment of the invention and not necessarily all embodiments. 
     The terms used in the claims should be construed to have the broadest reasonable interpretation consistent with the foregoing description. For example, the use of the article “a” or “the” in introducing an element should not be interpreted as being exclusive of a plurality of elements. Likewise, the recitation of “or” should be interpreted as being inclusive, such that the recitation of “A or B” is not exclusive of “A and B,” unless it is clear from the context or the foregoing description that only one of A and B is intended. Further, the recitation of “at least one of A, B and C” should be interpreted as one or more of a group of elements consisting of A, B and C, and should not be interpreted as requiring at least one of each of the listed elements A, B and C, regardless of whether A, B and C are related as categories or otherwise. Moreover, the recitation of “A, B and/or C” or “at least one of A, B or C” should be interpreted as including any singular entity from the listed elements, e.g., A, any subset from the listed elements, e.g., A and B, or the entire list of elements A, B and C. 
     
       
         
           
               
             
               
                   
               
               
                 LIST OF REFERENCE NUMERALS 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
            
               
                   
                 Connection terminal 
                 100 
               
               
                   
                 Housing 
                 10 
               
               
                   
                 First connection space 
                 11 
               
               
                   
                 Second connection space 
                 12 
               
               
                   
                 First conductor insertion opening 
                 13 
               
               
                   
                 Second conductor insertion opening 
                 14 
               
               
                   
                 First busbar piece 
                 15 
               
               
                   
                 Second busbar piece 
                 16 
               
               
                   
                 First torsion spring 
                 17 
               
               
                   
                 Second torsion spring 
                 18 
               
               
                   
                 Clamping limb 
                 19 
               
               
                   
                 Retaining limb 
                 20 
               
               
                   
                 Arcuate portion 
                 21 
               
               
                   
                 Clamping limb 
                 22 
               
               
                   
                 Retaining limb 
                 23 
               
               
                   
                 Edge region 
                 24 
               
               
                   
                 Free end 
                 25 
               
               
                   
                 Edge region 
                 26 
               
               
                   
                 Free end 
                 27 
               
               
                   
                 Receiving space 
                 28 
               
               
                   
                 Rear wall 
                 29 
               
               
                   
                 Wall 
                 30 
               
               
                   
                 Arcuate portion 
                 31