Abstract
A clamping spring for a screwless connection terminal for clamping a conductor, has a clamping limb, a contact limb, and a tensioning limb, the tensioning limb being connected to the clamping limb and the contact limb, and the clamping limb and the contact limb being designed as intersecting limbs. In the clamping limb, a clamping opening is provided, through which the contact limb extends, such that the contact limb is in contact with an edge of the clamping opening remote from the tensioning limb in a pretensioned manner and an exposed wire end of a conductor can be clamped with the contact limb onto a contact surface of a contact element of a screwless connection terminal. Furthermore, the clamping limb has a clamping extension having a clamping surface. The clamping extension, starting from the free end of the clamping limb remote from the tensioning limb, initially extends away from the tensioning limb, then extends back in the direction of the tensioning limb in a substantially curved form, and finally is oriented in the direction of the contact limb.
Claims
1. A clamping spring for a screwless connection terminal for connecting a conductor, wherein the clamping spring has a clamping limb, a contact limb, and a tensioning limb, the tensioning limb being connected to the clamping limb and the contact limb, and the clamping limb and the contact limb being designed as intersecting limbs, wherein the clamping limb has a clamping opening through which the contact limb extends, such that the contact limb is in contact with an edge of the clamping opening remote from the tensioning limb in a pretensioned manner and an exposed wire end of a conductor can be clamped with the contact limb onto a contact surface of a contact element of a screwless connection terminal, wherein the clamping limb has a clamping extension having a clamping surface, characterized in that: said clamping extension, starting from the free end of the clamping limb remote from the tensioning limb, initially being formed so as to extend away from the tensioning limb, being then formed so as to extend back in the direction of the tensioning limb in a substantially curved form, and finally being oriented in the direction of the contact limb.
2. The clamping spring according to claim 1, characterized in that the clamping extension, starting from the free end of the clamping limb remote from the tensioning limb, is initially formed substantially semicircular having a curvature pointing away from the tensioning limb and is then aligned in an arcuate transition substantially parallel to the contact limb.
3. The clamping spring according to either claim 1, characterized in that the clamping extension is integrally formed on the clamping limb.
4. The clamping spring according to either claim 1, characterized in that the clamping extension is attached to the clamping limb by means of a joining process, wherein the joining can also be an integral joining process such as welding or soldering.
5. The clamping spring according to claim 1, characterized in that the clamping extension has the same material as the clamping spring.
6. The clamping spring according to claim 1, characterized in that the clamping surface of the clamping extension at least partially has a surface profiling.
7. The clamping spring according to claim 1, characterized in that the clamping spring and/or the clamping extension is designed as a whole as a single stamped and bent part.
8. The clamping spring according to claim 1, characterized in that the clamping surface forms a flat pressure region and/or in that the exposed wire end of the conductor can be pressed by means of the clamping surface of the clamping extension flat onto the contact surface of the contact element.
9. A screwless connection terminal for connecting an electrical conductor with a clamping spring according to claim 1, wherein the connection terminal has a contact element to which the conductor is to be electrically connected and which has a connection portion and a contact surface, wherein the conductor to be connected is to be clamped between a surface portion of the clamping surface of the clamping extension and the contact surface of the contact element.
10. The screwless connection terminal according to claim 9, characterized in that the clamping surface of the clamping extension and/or the contact surface of the contact element at least partially has a surface profiling.
11. An electrical plug connection, characterized in that it comprises at least one screwless connection terminal according to claim 9.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) Further advantages, features, and possible applications of the present invention will become clear from the following description of embodiments thereof and the associated drawings.
(2) FIG. 1A to 1D: show an embodiment of a clamping spring in the profile view (FIG. 1A), in a view from below in the direction of arrow C onto the clamping spring (FIG. 1B), in a side view in the direction of arrow A onto the clamping spring according to FIG. 1A, and in perspective (FIG. 1D),
(3) FIG. 2A to 2D: show a contact element designed as a contact sleeve and a contact pin, each having a clamping spring according to FIG. 1A to 1D, which are mechanically inserted into one another and electrically connected, in the profile view, longitudinal section view, in perspective, and cross section view,
(4) FIG. 3A to 3D: show a contact sleeve as a contact element having a clamping spring according to FIG. 1A to 1D in profile view, side view, top view, and in perspective,
(5) FIG. 4A to 4D: show a contact pin as a contact element having a clamping spring according to FIG. 1A to 1D in profile view, side view, top view, and in perspective.
DETAILED DESCRIPTION
(6) FIG. 1A to 1D show an embodiment of a bent clamping spring 1 in a profile view (FIG. 1A), in a view from below in the direction of arrow C onto the clamping spring (FIG. 1B), in a view in the direction of arrow A onto the clamping spring 1 according to FIG. 1A, and in perspective (FIG. 1D), wherein the clamping spring 1 in the illustrated preferred embodiment is designed as a cage tension spring 1, is preferably made of metal, and has a clamping limb 7, a contact limb 8 and a tensioning limb 9. The clamping limb 7 and the contact limb 8 are connected to one another via the tensioning limb 9, as shown in FIGS. 1A and 1D. A clamping opening 6 is recessed in the clamping limb 7 of the cage tension spring 1 (FIG. 1D), which allows for the intersection between the clamping limb 7 and the contact limb 8. Through the clamping opening 6 of the cage tension spring 1, the exposed wire ends 2a of a conductor 2, which, however, is not shown in FIG. 1A to 1D, can be introduced in the insertion direction E shown in FIG. 1A. The exposed wire ends 2a of a conductor 2 inserted into the clamping opening 6 are then in contact with the edge of the clamping opening 6 that is remote with respect to the tensioning limb 9, which represents a first pressure region with a small cross section and, due to its incisive effect, acts as a knife edge 12 in the exposed wire ends 2a (FIG. 1D). The clamping limb 7 also has a clamping extension 10 with a clamping surface 11, the clamping surface 11 forming a second flat pressure region. In the embodiment shown, the clamping extension 10 is integrally formed on the clamping limb 7, has the same material as the clamping limb 7, and can be viewed as an extension of the clamping limb 7. As shown in FIGS. 1A and 1D, said clamping extension 10 starts from the free end of the clamping limb 7 remote from the tensioning limb 9 and extends initially away from the tensioning limb 9 so as to extend back again in the direction of the tensioning limb 9 in a substantially curved form, and finally is oriented extending in the direction of the contact limb 8. In a further embodiment, the substantially curved shape of the clamping extension is semicircular. The clamping surface 11 of the clamping extension 10 is always oriented substantially parallel to the surface of the contact limb 8 and thus extends in the insertion direction E of a conductor 2 to be electrically connected (not shown in FIG. 1A to 1D).
(7) FIG. 2A to 2D represent a clamping spring 1 according to one embodiment of the invention attached to a screwless connection element, in this case designed as a cage tension spring 1 according to FIG. 1A to 1D having a clamping limb 7, a contact limb 8, and a tensioning limb 9, each having a contact element 5 in the form of a contact pin 5 and a contact sleeve or socket 5, which are mechanically inserted into one another and electrically connected. Both the contact pin 5 and the contact sleeve 5 each have a connection portion 3 having a contact surface 4, which are electrically connected to a conductor 2 by means of its exposed wire ends 2a. FIG. 2B shows a longitudinal section of the arrangement shown in FIG. 2A, FIG. 2C shows a perspective view, and FIG. 2D shows a cross section. The exposed wire ends 2a of the conductor 2 are on the one hand pressed flatly onto the contact surfaces 4 of the respective contact elements 5 by means of the clamping surface 11 of the clamping extension 10, as shown in FIG. 2B. Due to the large clamping surface 11 of the clamping extension 10, the contact surface stressed by the exposed wire ends 2a comes into contact with almost the entire usable electrical contact surface 4 of the respective contact element 5 (FIG. 2D). This results in a very good transmission of the current between the exposed wire end 2a of the conductor 2 and the contact surface 4 of the respective contact element 5, since larger electrical contact surfaces having low electrical losses are created. On the other hand, the exposed wire ends 2a of the conductor 2 are clamped by means of the clamping extension 10 between the edge of the clamping opening 6 of the clamping limb 7 and the contact surface 4 of the respective contact element 5, which is remote in relation to the tensioning limb 9 and formed as a knife edge 12, in that the clamping extension 10 exerts pressure on the edge of the clamping opening 6 of the clamping limb 7, which is remote in relation to the tensioning limb 9 and is formed as a knife edge 12 (FIG. 2C). The small pressurized surface at the edge of the clamping opening 6, which is referred to as the knife edge 12 due to its small cross section and its resulting incisive effect, can cut deeper into the strands and in the case of a wire end sleeve arranged on the exposed wire end 2a of the conductor 2 can cut into corresponding notches, so that the exposed wire end 2a is clamped particularly strongly, a high tensile strength is given in the insertion direction E of the conductor 2, and consequently an unintentional release from the clamped position in the insertion direction E of the conductor 2 is not possible. In addition, because of its strong clamping force and its correspondingly provided high tensile strength, the knife edge 12 relieves the main strain on the pull-out forces of the clamping spring 1. The presence of two pressurized surfaces, namely the clamping surface 11 of the clamping extension 10 and the knife edge 12 at the edge of the clamping opening 6, with which the electrical contact is ensured between the exposed wire ends 2a of a conductor 2 and the contact surface 4 of the respective contact element 5, ensures, in addition to the advantages already mentioned, that the exposed wire end 2a of the conductor 2 does not bend when it is inserted into the clamping opening 6, since the two pressurized surfaces discussed above simultaneously ensure that the exposed wire end 2a is clamped. Furthermore, the simultaneous clamping of the exposed wire end 2a on two pressurized surfaces has the advantage that with one and the same clamping spring 1 both a good transmission of the current and a high tensile strength in the insertion direction E of the conductor 2 with simultaneous main strain relief through the knife edge 12 is made possible, while a clamping extension 10 according to the prior art with only one formed pressure region can be designed either for a good transmission of the current or for a high tensile strength in the insertion direction E of the conductor 2.
(8) FIG. 3A to 3D and FIG. 4A to 4D show in each case an embodiment of a clamping spring 1 attached to a screwless connection element, which is designed as a cage tension spring 1 having a clamping limb 7, a contact limb 8, and a tensioning limb 9 according to FIG. 1A to 1D, having a contact element 5 designed as a contact sleeve 5 in the case of FIG. 3A to 3D and as a contact pin 5 in the case of FIG. 4A to 4D. FIGS. 3B and 4B each show a longitudinal section of the arrangement shown in the corresponding FIGS. 3A and 4A, FIGS. 3C and 4C show a perspective view, and FIGS. 3D and 4D show a cross section. The cage tension spring 1 is in each case mounted in a pretensioned manner on the contact element 5. When assembling the cage tension spring 1, the protruding section of the connection element 3 of the contact sleeve 5 (FIG. 3A to 3C) or the contact pin 5 (FIG. 4A to 4C) are introduced through the clamping opening 6 in such a way that the protruding section of the connection element 3 is at least partially in contact with the contact limb 8 of the cage tension spring 1 and the clamping extension 10 is also in contact with its clamping surface 11 on the protruding section of the connection element 3 if no conductor has yet been inserted. In addition, the clamping limb 7 of the clamping spring 1 is in contact with the end face of the contact element 1. This creates a force-fit connection and fixation of the cage tension spring 1 on the contact element 5.
(9) Attention is drawn to the fact that all features that are apparent to a person skilled in the art from the present description, and the drawings, even if these features were only described in connection with certain further features, can be combined both individually and in any desired combinations with other features or groups of features disclosed in the present invention, unless this has been explicitly excluded or technical circumstances make such combinations impossible or meaningless. For the sake of brevity and legibility of the description, a comprehensive, express description of all possible combinations of features has been avoided. The scope of protection of the present invention defined by the claims is not restricted by the embodiments of the invention which are shown in detail in the description and the drawings and are only used by way of example. Modifications of the disclosed embodiments will be apparent to a person skilled in the art from the drawings, the description, and the accompanying claims. The word “having” cited in the claims does not exclude other elements or steps. The indefinite article “a” or “an” does not exclude a plurality. The combination of features that are claimed in different claims is not excluded.
LIST OF REFERENCE SIGNS
(10) 1 Clamping spring 2 Electrical conductor 2a Exposed wire end of an electrical conductor 3 Connection portion 4 Contact surface 5 Contact element 6 Clamping opening 7 Clamping limb 8 Contact limb 9 Tensioning limb 10 Clamping extension 11 Clamping surface 12 Knife edge E Direction of insertion
