Patent Publication Number: US-10784599-B2

Title: Connection clip

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/EP2017/063682, filed on Jun. 6, 2017, and claims benefit to Luxembourg Patent Application No. LU93148, filed on Jul. 13, 2016. The International Application was published in German on Jan. 18, 2018 as WO 2018/010893 under PCT Article 21(2). 
     FIELD 
     The invention relates to a connection terminal for connecting an electrical conductor, comprising a housing, a current bar arranged in the housing, a clamping spring arranged in the housing and a pivotally mounted actuation lever, it being possible for the clamping spring to be transferred to an open position and to a closed position by means of a pivoting movement of the actuation lever, and the clamping spring comprising a clamping limb for clamping a conductor inserted into the housing against the current bar in the closed position. 
     BACKGROUND 
     A corresponding connection terminal in which a clamping spring can be transferred to an open position and a closed position by means of an actuation lever is known from DE 697 03 829 T2. The actuation lever is pivotally mounted in the housing. The actuation lever comprises a rounded arm by means of which the actuation lever grips the clamping spring on a tension element formed on the clamping spring in order to transfer the clamping spring from the closed position to the open position by applying a tensile force. The structure of the clamping spring, and of the connection terminal as a whole, is very elaborate and complex. Connecting a conductor using a connection terminal of this type is also less convenient for a user. 
     SUMMARY 
     In an embodiment, the present invention provides a connection terminal for connecting an electrical conductor, comprising: a housing; a current bar arranged in the housing; a clamping spring arranged in the housing; and a pivotally mounted actuation lever, wherein the clamping spring is transferrable to an open position and to a closed position by a pivoting movement of the actuation lever, wherein the clamping spring comprises a clamping limb configured to clamp a conductor that is inserted into the housing against the current bar in the closed position, and wherein an actuation tab is arranged on the clamping limb such that when the clamping spring is transferred from the closed position to the open position, a compressive force is applied to the actuation tab by the actuation lever. 
    
    
     
       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 the invention, 
         FIG. 2  is a schematic partial sectional view of the connection terminal shown in  FIG. 1  with the clamping spring in the closed position, 
         FIG. 3  is a schematic partial sectional view of the connection terminal shown in  FIG. 1  with the clamping spring in the open position, and 
         FIG. 4  is another view of part of the connection terminal shown in  FIG. 1  with the clamping spring in the closed position. 
     
    
    
     DETAILED DESCRIPTION 
     An aspect of the present invention provides a connection terminal which allows a conductor to be securely connected and the structure of the connection terminal to be less complex. 
     The connection terminal according to the invention is characterized in that an actuation tab is arranged on the clamping limb such that when the clamping spring is transferred from the closed position to the open position, a compressive force is applied to the actuation tab by the actuation lever. According to the invention, a compressive force, rather than a tensile force, is applied to the actuation tab and thus to the clamping spring by means of an actuation lever in order to open said spring. The actuation tab is arranged directly on the clamping limb of the clamping spring, such that the force that acts on the actuation tab can directly cause the clamping limb to move without the need to use additional elements that are independent of the clamping spring or elements that are additionally provided on the clamping spring. Loss of energy from the acting compressive force for actuating the clamping limb of the clamping spring can thus be prevented. The connection terminal is thus highly efficient, and therefore a conductor can be connected and released very securely. Ease of operation for a user of the connection terminal can therefore also be significantly improved. The direct action on the clamping limb via the actuation tab linked thereto also allows the structural design of the connection terminal to be less complex. The compressive force applied to the actuation tab preferably acts counter to the direction in which the conductor is inserted into the connection terminal, and also counter to the movement direction of the clamping limb during the movement from the closed position to the open position. When the actuation lever pivots, the actuation lever presses against the actuation tab and the actuation tab is consequently also moved, in particular pivoted, together with the clamping limb of the clamping spring arranged thereon. In contrast, the contact limb of the clamping spring, which contact limb is linked to the clamping limb by means of a curved connection portion, preferably remains in position and is not moved or pivoted when the compressive force is applied to the actuation tab. 
     The actuation tab is preferably arranged on the clamping limb only on one side. The actuation tab is preferably arranged on a transverse lateral face of the clamping limb that extends along the length of the clamping limb. The fact that the actuation tab is linked to the clamping limb on one side allows the width of the connection terminal to be reduced. 
     The actuation tab is preferably divided into two regions. The actuation tab preferably comprises a linking region that is arranged directly on the clamping limb and a pressure region that is arranged on the linking region, the pressure region preferably being spaced apart from the clamping limb. The pressure region is the region of the actuation tab at which the compressive force is applied to the actuation tab by the actuation lever. The pressure region preferably does not come into direct contact with the clamping limb, and instead only comes into direct contact with the linking region which is connected to the clamping limb. 
     The pressure region is preferably formed in a different plane from the linking region. The plane spanned by the pressure region is preferably formed at an angle of &gt;0, preferably at an angle of &gt;45°, with respect to the plane spanned by the linking region. The pressure region is preferably formed at an angle of 90° with respect to the linking region. The pressure region preferably extends along the width of the clamping spring, and thus transversely to the longitudinal extension of the clamping spring or of the clamping limb of the clamping spring, such that the compressive force that acts on the pressure region at an angle of 90° acts along the longitudinal extension of the clamping spring or of the clamping limb of the clamping spring. The clamping spring can thus be prevented from tilting laterally when the compressive force is applied to the actuation tab. 
     In order to achieve a secure link between the actuation tab and the clamping spring and thus to be able to securely transfer the compressive force that acts on the actuation tab to the clamping spring, the actuation tab and the clamping spring are preferably formed integrally with one another. In this case, the clamping spring and the actuation tab are preferably formed by a metal strip so as to be curved. 
     A peg-shaped actuation region is preferably formed on the actuation lever for applying the compressive force. A defined compressive force having a defined pressure point can be applied to the actuation tab by means of the peg-shaped actuation region. 
     In order to increase ease of operation for the user of the connection terminal, the actuation lever can be positioned with respect to the actuation tab such that the actuation lever is held in the open position in a self-locking manner. The self-locking effect allows the actuation lever to remain in the open position independently, and said lever therefore does not need to be held in position by the user. The self-locking effect is preferably designed such that, in the open position, a pressure point that acts when the compressive force is applied to the actuation tab by means of the actuation lever is arranged above a swivel pin of the actuation lever. A self-locking effect of the actuation lever can therefore be achieved without significant design complexity. 
       FIG. 1  shows a connection terminal  100  for connecting an electrical conductor. 
     The connection terminal  100  comprises a housing  10  in which a current bar  11 , a clamping spring  12  and an actuation lever  13  are received, as can be seen in particular in FIG.  2 . The housing  10  is formed in two parts, the two housing parts being detachably connected to one another via a plug connection or a screw connection. A conductor insertion opening  14  via which a conductor to be connected can be inserted into the connection terminal  100  is arranged in the housing  10 . The housing  10  also comprises an opening  15  via which a part of the actuation lever  13 , in particular a handle  16  for actuating the actuation lever  13 , protrudes from the housing  10 . The opening  15  is formed in an upper face  17  of the housing  10 . 
     As can be seen in  FIG. 2 , the clamping spring  12  comprises a clamping limb  18  and a contact limb  19  which are interconnected by means of a curved connection portion  20 . The clamping spring  12  is mounted in the housing  10  such that the clamping limb  18  is movable, so that the clamping spring  12  can be transferred into an open position in which a conductor to be connected can be inserted into and released from the clamping space that is formed by the clamping spring  12  and the current bar  11 , and into a closed position in which a conductor to be connected is clamped against the current bar  11  by the clamping limb  18 . 
     The housing  10  has a curved inner contour  21  that is adapted to the shape of the curved connection portion  20  such that the curved connection portion  20  can rest against the inner contour  21  in a precise fit and the clamping spring  12  can thus be secured in the housing  10 . Unlike the clamping limb  18 , the contact limb  19  is arranged in the housing  10  rigidly such that when the clamping spring  12  is transferred to the open position and the closed position, the contact limb  19  does not move, but instead remains in position. 
     A U-shaped projection  22  which is used as a stop or penetration guard for a conductor that is inserted into the housing  10  is arranged on the clamping spring  12 . The projection  22  also receives the current bar  11 , by virtue of the fact that the projection  22  comprises an opening  23  through which the current bar  11  is fed such that the current bar  11  rests flat against an inner face of the projection  22 . The projection  22  is formed integrally with the clamping spring  12 , the projection  22  being connected to the contact limb  19 . The clamping spring  12 , together with the projection  22 , is formed by a curved metal strip. 
     Furthermore, an actuation tab  24  is arranged on the clamping spring  12 , which tab is arranged on the clamping limb  18  of the clamping spring  12  such that when the clamping spring  12  is transferred from the closed position to the open position, the actuation lever  13  applies a compressive force F D  to the actuation tab  24 . In order to transfer the clamping spring  12  from the closed position to the open position, force is not applied directly to the clamping spring  12 , in particular to the clamping limb  18  of the clamping spring  12 , but is instead applied indirectly via the actuation tab  24 . The compressive force F D  acts counter to the movement direction B K  or the deflection of the clamping limb  18  during the movement from the closed position to the open position.  FIGS. 2 and 4  show the clamping spring  12  in the closed position and  FIG. 3  shows the clamping spring  12  in the open position. 
     The actuation tab  24  is linked to the clamping limb  18  of the clamping spring  12  on one side, the actuation tab  24  being linked to a transverse lateral face  25  of the clamping limb  18  that extends along the length of the clamping limb  18 . In the embodiment shown here, the actuation tab  24  is formed integrally with the clamping limb  18  and thus with the clamping spring  12 . 
     The actuation tab  24  is divided into two regions, namely a linking region  26  and a pressure region  27 . 
     The linking region  26  is the region by means of which the actuation tab  24  is linked to the clamping limb  18  of the clamping spring  12 . The linking region  26  extends laterally with respect to the clamping spring  12  and extends, beginning at the clamping limb  18 , beyond the contact limb  19  such that the linking region  26  overlaps the contact limb  19 . 
     Unlike the linking region  26 , the pressure region  27  is spaced apart from the clamping limb  18 , such that there is no direct connection between the pressure region  27  and the clamping limb  18 . The pressure region  27  is the region at which the compressive force F D  is applied to the actuation tab  24  by means of the actuation lever  13 . The pressure region  27  is arranged above the contact limb  19 . The pressure region  27  is preferably formed at an angle of 90° with respect to the linking region  26 . The pressure region  27  extends along the width of the clamping spring  12  and thus transversely to the longitudinal extension of the clamping spring  12  or of the clamping limb  18  and the contact limb  19  of the clamping spring  12 , such that the compressive force F D  that acts on the pressure region  27  at an angle of 90° acts along the longitudinal extension of the clamping spring  12  or of the clamping limb  18  of the clamping spring  12 . The pressure region  27  extends over the entire width of the clamping spring  12 . 
     A peg-shaped actuation region  28  that presses directly against the pressure region  27  of the actuation tab  24  (which can be seen in particular in  FIG. 3 ) is formed on the actuation lever  13  for applying the compressive force F D . While moving from the closed position to the open position, the actuation lever  13 , together with the peg-shaped actuation region  28 , rolls on the surface of the pressure region  27  in order to apply the compressive force F D . For this reason, the actuation lever  13  is pivotally mounted about a swivel pin  29 . 
     The actuation lever  13  is positioned with respect to the actuation tab  24  such that the actuation lever  13  is held in the open position in a self-locking manner, and thus remains in the open position independently, as shown in  FIG. 3 , without the need for a user to hold the actuation lever  13  in said position. In order to achieve the self-locking effect, a pressure point P D  that acts when the compressive force F D  is applied to the actuation tab  24  by means of the actuation lever  13  is arranged above the swivel pin  29  in the open position. The pressure point P D  is the point by means of which the tip  30  of the peg-shaped actuation region  28  of the actuation lever  13  presses against the pressure region  27  of the actuation tab  24  in the open position. In order to transfer the clamping spring  12  from the open position to the closed position so as to close the clamping space, the actuation lever  13  is rotated back over said pressure point P D  by a user. 
     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 SIGNS 
     
         
         Connection terminal  100   
         Housing  10   
         Current bar  11   
         Clamping spring  12   
         Actuation lever  13   
         Conductor insertion opening  14   
         Opening  15   
         Handle  16   
         Upper face  17   
         Clamping limb  18   
         Contact limb  19   
         Curved connection portion  20   
         Inner contour  21   
         Projection  22   
         Opening  23   
         Actuation tab  24   
         Transverse lateral face  25   
         Linking region  26   
         Pressure region  27   
         Actuation region  28   
         Swivel pin  29   
         Tip  30   
         Compressive force F D    
         Movement direction of the clamping limb of the B K    
         clamping spring 
         Pressure point P D