This application is a national phase of International Application No. PCT/EP2014/068502 filed Sep. 1, 2014.
The invention relates to a spring-loaded connection terminal having a busbar piece which has a base surface and side walls which project from the sides of the base surface, wherein opposite side walls delimit a receiving space on both sides, and having a terminal arrangement for terminal connection of an electrical conductor to an associated clamping point, said clamping arrangement having at least one clamping spring which interacts with the busbar piece.
The invention further relates to a terminal component, in particular a terminal block, having an insulating-material housing and having at least one spring-loaded terminal connection of this kind.
Spring-loaded connection terminals for connecting electrical conductors are sufficiently well known in a variety of forms.
For example, DE 1 917 503 A discloses a screw-free connection or connecting terminal having a clamping spring which is mounted on a two-layer, folded-over busbar piece. Furthermore, said document describes a connection terminal having a spiral compression spring which is mounted between a U-shaped tensioning bracket and a busbar piece which is accommodated in the opening in the tensioning bracket. An electrical conductor then forms a terminal connection between a transverse edge of the tensioning bracket and the busbar piece.
DE 10 2005 058 307 A1 discloses an electrical connection terminal having cage tension springs which are mounted on a busbar. The busbar has side walls which are folded over on both sides and which laterally guide an electrical conductor which is guided to a clamping point.
Furthermore, DE 198 18 704 C1 discloses a mounting foot with a grounding conductor function for mounting a high-current terminal. A base plate of U-shaped cross section which is bent away in the direction of a carrying rail in square regions is provided in this case.
A mounting foot, which adjoins a busbar for a spring-loaded terminal connection, for a carrying rail is also described in DE 44 09 206 C1.
Against this background, the object of the present invention is to provide an improved spring-loaded connection terminal.
The object is achieved by the spring-loaded connection terminal having the features of claim 1 and also by the terminal component having the features of claim 10. Advantageous embodiments are described in the dependent claims.
For a spring-loaded connection terminal of this generic type, it is proposed that a current bar, which is separate from the busbar piece, is inserted into the receiving space in the busbar piece, and the current bar is arranged in order to form a clamping point for terminal connection of an electrical conductor.
The insertion of a separate current bar into a receiving space which is delimited by side walls of the busbar piece has the effect that the busbar piece itself can be manufactured from a relatively thin material which is easy to shape such that said busbar piece is optimized for the holding function of the clamping spring and possibly for a guiding function. However, the cross section of and the material selection for the separate current bar can be optimized for the primary current conducting function of said current bar. In this case, the receiving space which is delimited on both sides by the side walls securely receives the current bar while at the same time receiving and guiding the electrical conductor to the current bar in an improved manner. Therefore, owing to the busbar piece being designed separately from an additional current bar, the functions of the two components can be separated.
The busbar piece of U-shaped cross section does not necessarily have to be designed as an electrically conductive metal part in this case. It can also be formed from a different material to the current bar or at least from a metal sheet which is considerably thinner than the current bar.
It is particularly advantageous when the current bar has at least one protruding clamping edge on that side which is opposite the bearing surface of the current bar by way of which the current bar rests on the busbar piece. This ensures that an electrical conductor does not rest flat on the current bar, but rather the clamping force of the clamping spring is concentrated on a defined contact region (contact point) which is provided by the clamping edge. Therefore, it is possible to increase the surface pressure of the electrical conductor on the current bar with the aid of the protruding clamping edges.
The spring-loaded connection terminal has at least one tensioning bracket of U-shaped cross section which is mounted on the busbar piece, such that it can move on the busbar piece, in a direction perpendicular to the plane of the bearing surface of the current bar. The tensioning bracket has at least one transverse web which engages beneath the current bar. In the process, said at least one transverse web and the adjacent current bar form a clamping point for terminal connection of an electrical conductor between the transverse web and the current bar. A clamping spring is operatively connected to the busbar piece and the associated tensioning bracket in order to exert a spring force, which forces the transverse web of the bracket in the direction of the current bar, on the tensioning bracket. Therefore, a clamping force is exerted on an electrical conductor which is positioned between the transverse web and the current bar.
The clamping spring can be, for example, a spiral compression spring. In this case, a spiral compression spring of this kind is positioned between a head section of the U-shaped tensioning bracket, from which two tensioning bracket arms extend at a distance from one another, and the busbar piece. In this case, the spiral compression spring can rest either directly on the busbar piece or on a metal tunnel sheet which is connected to the busbar piece.
However, it is also feasible for the clamping spring to be a cage tension spring which is mounted on the busbar piece. A cage tension spring of this kind has a contact limb which is mounted on the busbar piece, a spring bend which adjoins the contact limb, an operating limb which adjoins the spring bend, and a clamping limb which is deflected from the operating limb in the direction of the busbar piece. The clamping limb has an opening which is delimited by a transverse web. The busbar piece, together with the current bar which bears against it, projects through the opening. In this case, the transverse web, together with the adjacent current bar, forms a clamping point for terminal connection of an electrical conductor between the transverse web and the current bar.
A very compact spring-loaded connection terminal in which lateral guidance is provided with the aid of the busbar piece can be realized with a cage tension spring of said kind. Optimum current transmission with the lowest possible transfer resistance is achieved with the aid of the separate current bar. The busbar piece can be easily folded over with the aid of the busbar piece which is produced from a thin sheet-metal material for example, wherein the wall thickness of the folded-over side walls are relatively thin in order to ensure the smallest possible width of the spring-loaded terminal connection. Therefore, only the separate current bar has to be adapted to meet the requirements for optimum electrical conduction of current and terminal connection of an electrical conductor.
It is particularly advantageous when additional fastening elements for fastening the current bar to the busbar piece are provided. In this way, the busbar piece is not only received into the receiving space, which is delimited at the sides by the side walls, of the busbar piece and mounted in position there, but rather additionally secured to the busbar piece. This can be performed, for example, by riveting, welding, soldering, adhesively bonding or screwing the current bar to the busbar piece. To this end, the current bar and the busbar piece preferably have fastening holes through which the suitable fastening parts, such as rivets, screws or the like, are guided. These fastening parts, together with the fastening holes, form fastening elements within the meaning of the present invention.
The invention will be explained below with reference to exemplary embodiments, by way of example using the attached drawings, in which:
Said figure shows that the conductor terminal connection on the left-hand side with the clamping spring 8 which is relieved of tension is in the clamping position in which an electrical conductor would be pushed in the direction of the base surface 6 of the busbar piece 5.
However, the conductor terminal connection on the right-hand side is in the open position in which the clamping spring 8 is compressed with the aid of an operating element 9 in order to open a clamping point for an electrical conductor.
In this case, the clamping point is formed by at least one clamping edge at the lower end of a U-shaped tensioning bracket 10 and by a current bar (not visible) on the base surface 6 in the receiving space, which is delimited by the side walls 7, of the busbar piece 5. It is clear that, in the clamping position in the case of the conductor connection terminal on the left-hand side, the tensioning bracket 10 is shifted upward by the compression spring which is relieved of tension, so that the lower free end of the tensioning bracket 10 moves in the direction of the base surface 6 in comparison to the open position of the conductor terminal connection which is on the right-hand side.
In this embodiment, the clamping spring 8 is a spiral compression spring which is mounted between the base 11 of the tensioning bracket 10 and a metal tunnel sheet 14. The metal tunnel sheet 14 is fastened to the busbar piece 5 by clamping lugs 13. In this case, said clamping lugs 13 engage into recesses in the side walls of the busbar piece 5 in order to fix the metal tunnel sheet 14 in position.
A tunnel sheet-metal spring 15 is arranged between the metal tunnel sheet 14 and the base surface 6 of the busbar piece 5, it being possible for a pin contact of a link to be received and for electrical contact to be made with said pin contact by said tunnel sheet-metal spring between the metal tunnel sheet 14 and the busbar piece 5.
The operating element 9 has a threaded bar 16 which extends concentrically through the clamping spring 8, is mounted in a rotatable manner on a rotary bearing 17 at an upper end and fixed to the base 11 of the tensioning bracket 10 in its direction of longitudinal extent, and forms an axial bearing. The threaded bar 16 enters a corresponding threaded sleeve 18 of a clamping bushing 12 which extends from the metal tunnel sheet 14 in the direction of the base 11 of the tensioning bracket 10 and is fastened to the metal tunnel sheet 14. The threaded rod 16 can be rotated, for example, with the aid of a screwdriver which is inserted into an operating head 19 at the free end of the threaded rod 16. In this case, the threaded rod 16 enters the threaded sleeve 18 or is further unscrewed from the threaded sleeve 18 in order to relieve tension from the clamping spring 8 or to press said clamping spring in order to open the clamping point. In the open position, which is shown for the conductor connection terminal on the right-hand side, the tensioning bracket 10 can be held in the open position with the aid of a locking element 20 which is mounted in the insulating-material housing 2 in a displaceable manner. In this case, said locking element 20 is pushed in the direction of the rotary bearing 17 from outside the insulating-material housing 2, in order to engage over the rotary bearing 17. In this case, the locking element 20 is spring-loaded with the aid of a compression spring 51 in order to automatically return the locking element 20 to the unlocking position (see position of the conductor terminal connection on the left-hand side) when the pressure force which is exerted by the tensioning bracket 10 and the rotary bearing 17 on the locking element 20 is reduced or removed, for example, by slightly pushing down the tensioning bracket 10 in the direction of the busbar piece 5.
Corresponding guide grooves 22 are made in the insulating material housing for the purpose of guiding the opposite tensioning arms 21 of the U-shaped tensioning bracket 10.
It is further clear that the tensioning arms 21 have, for example, rectangular openings 26 through which, in particular, the current bar 25 projects. “Project through” is understood to mean that the current bar 25 projects into the opening 26 regardless of whether the free end of the current bar 25 protrudes out of the plane of the tensioning arm 21 on the other side or not.
A sufficient cross section with an optimally selected material for the current bar 25 in respect of the current conducting function can be provided with the aid of said separate current bar 25. However, the busbar piece 5 can be produced from a relatively thin and easily deformable sheet-metal material, wherein the material selection does not depend on the current conducting capability. The busbar piece 5 can be formed from relatively inexpensive sheet metal or else from other, under certain circumstances also electrically insulating, materials, such as fiber-reinforced plastic for example. Therefore, it is feasible for the busbar piece 5 itself to be produced, for example by injection-molding with suitable fiber reinforcement, as a metal casting or the like.
Said figure further shows that the metal tunnel sheet 14 is fastened to the busbar piece 5 in a manner fixed in position by the bearing arms 13. In this case, the bearing plane of the metal tunnel sheet 14 is at a distance from the base surface 6 of the busbar piece 5, and therefore there is an intermediate space for receiving the tunnel sheet-metal spring 15 (not shown in
Furthermore, fastening elements in the form of fastening holes 28 are provided in the base surface 6.
The current bar 25 is then fastened to the busbar piece 5 with the aid of rivets, screws or similar fastening elements 29 which project through the fastening holes 28. However, it is also feasible for the current bar 25 to be welded or, under certain circumstances, also adhesively bonded to the busbar piece 5 in the region of the fastening openings 28.
It is further clear that the current bar 25 is received in the receiving space 35 of the U-shaped busbar piece 5, which is delimited by the opposite side walls 7 and the upper base surface, and is longer than the busbar piece 5. In this way, the free ends of the current bar 25 protrude from the busbar piece 5.
Said figure further shows that a protrusion 31 is provided in the central region, a V-shaped clearance between the base surface 6 of the busbar part 5 and the current bar 25 being formed in cross section by said protrusion. A test tap 34 (see
It is further clear that the base surface 6 is deformed in the direction of the current bar 25 in the center in the region of the section C-C, in order to in this way provide an interlocking connection between the busbar piece 5 and the current bar 25.
A difference can be found in the configuration of the current bar which, in this embodiment, has two parts and consists of a first current bar part 25a and a second current bar part 25b. The two current bar parts 25a, 25b are bent away downward from the base surface 6 of the busbar piece 5 from the plane of the base surface 6 of the busbar piece 5 in the central region in alignment with the test pin opening and the test pin 34 and extend parallel to one another and such that they rest against one another in this region. In the part 45a, 45b of the current bar parts 25a, 25b which point away from the base surface 6 of the busbar piece 5 in a perpendicular manner, the two adjoining sections of the current bar parts 25a, 25b are connected to one another in an interlocking manner, for example, by welding, riveting, caulking, latching or screwing. The sections of the current bar parts 25a, 25b which extend away from the busbar piece 5 form bearing sections 37a, 37b which are deflected by way of their free ends so as to point away from one another once again at a distance from the base surface 6. Therefore, a bearing of the terminal component 1 for mounting on a carrying rail (not illustrated) is provided in order to mount the carrying rail on the bearing sections 37a, 37b and to latch the free side edges of the carrying rail between the bearing sections 37a, 37b and latching tabs 38 of a latching lug 39 of the terminal component 1.
Therefore, the two-part current bar 25a, 25b can be used firstly to electrically connect the electrical conductors to the carrying rail 40 for providing a grounding conductor contact, and also to mechanically fixedly and securely mount the terminal component 1 on the carrying rail. To this end, carrying rail latching elements 41 which, by way of a base surface 42, rest on the free ends of the bearing sections 37a, 37b of the current bar parts 25a, 25b are provided. Two latching fingers 43 are then bent downward away from the busbar piece 5 at the side walls of the free ends of the bearing sections 37a, 37b, so that latching tabs 38 which are arranged on said latching fingers engage beneath a free side edge 44 of a carrying rail 40. In this way, the carrying rail 40 is latched between the bearing sections 37a, 37b and the latching lugs 38.
A spring clip 36 engages over the carrying rail latching elements 41 of L-shaped cross section and also engages over the perpendicular parts 45a, 45b of the current bar parts 25a, 25b. Therefore, the latching fingers 43 of the carrying rail latching elements 41 are subjected to the action of a force, the forces on said latching fingers being intended to oppose one another, by the spring force of the spring clip 36 in order to latch to a carrying rail 40.
It is further clear that the free ends of the bearing sections 37a, 37b are tapered by lateral incisions in order to guide the latching element 41 by way of the free ends of the bearing sections 37a, 37b.
The bearing sections 37a, 37b have a stamped portion 46 on their side which faces the carrying rail 40, in order to reduce the contact surface area with the carrying rail 40 and therefore to increase the surface pressure for improved current transfer values. The illustrated embodiment provides an optimally shortened current path from the terminal-connected electrical conductor to the carrying rail 40.
A cage tension spring 45 of this kind can also be arranged on the opposite side. However, it is also feasible for another terminal connection, such as a terminal connection with a tensioning bracket of the first and second embodiment for example, to be formed on said opposite side.
Number | Date | Country | Kind |
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10 2013 109 640 | Sep 2013 | DE | national |
Filing Document | Filing Date | Country | Kind |
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PCT/EP2014/068502 | 9/1/2014 | WO | 00 |
Publishing Document | Publishing Date | Country | Kind |
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WO2015/032718 | 3/12/2015 | WO | A |
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Entry |
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International Search Report and Written Opinion for corresponding International Application No. PCT/EP2014/068502 mailed Dec. 9, 2014. |
International Preliminary Report on Patentability for corresponding International Application No. PCT/EP2014/068502 mailed Mar. 8, 2016. |
Number | Date | Country | |
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20160226160 A1 | Aug 2016 | US |