DE102023200524B3 - Connection terminal and DIN rail device - Google Patents

Abstract

The connection terminal (100) according to the invention for a DIN rail device (1) for contacting an external connection conductor (50) has a clamping frame (130), a manually operable actuating element (107) rotatably mounted on the clamping frame (130) for opening and closing the connection terminal (130), a first spring element (110) arranged in the clamping frame (130), the first end (111) of which is designed to press the external connection conductor (50) that can be inserted into the clamping frame (130) against an electrical connection element (60) that can be arranged in the clamping frame (130), and a second spring element (120), the first end (121) of which is operatively connected to the second end (112) of the first spring element (110), and the second end (122) of which is connected to the actuating element (107), wherein the first spring element (110) has a lower spring hardness than the second spring element (120). The two spring elements (110, 120) thus act in series, i.e. one after the other in the temporal movement sequence of the actuating element (107). In this way, a compact design of the connection terminal (100) can be realized, which can be actuated without screws using the actuating element. The insertion of the external connection conductor (50) into the terminal frame (130) is thereby made significantly easier.

Description

The invention relates to a connection terminal, for example for a series terminal or a series-mounted device for contacting an external connection conductor. The invention also relates to a series-mounted device with such a connection terminal.

Electromechanical protective switching devices - for example circuit breakers, miniature circuit breakers, residual current circuit breakers and arc or fire protection switches - are used to monitor and protect an electrical circuit and are used in particular as switching and safety elements in electrical power supply and distribution networks. To monitor and protect the electrical circuit, the protective switching device is electrically connected to an electrical line of the circuit to be monitored via two or more connection terminals in order to interrupt the electrical current in the respective monitored line if necessary. For this purpose, the protective switching device has at least one switching contact which can be opened when a predefined state occurs - for example when a short circuit or a residual current is detected - in order to disconnect the monitored circuit from the electrical line network. Such protective switching devices are also known in the field of low-voltage technology as series-mounted devices.

Circuit breakers are specially designed for high currents. A miniature circuit breaker (MCB), also known as a miniature circuit breaker, is a so-called overcurrent protection device in electrical installations and is used in particular in the area of low-voltage networks. Circuit breakers and miniature circuit breakers guarantee safe shutdown in the event of a short circuit and protect consumers and systems from overload, for example from damage to electrical cables caused by excessive heating as a result of too high an electrical current. They are designed to automatically switch off a circuit to be monitored in the event of a short circuit or overload, thus isolating it from the rest of the network. Circuit breakers and miniature circuit breakers are therefore used in particular as switching and safety elements for monitoring and protecting an electrical circuit in electrical power supply networks. Miniature circuit breakers are known from the publications EP 2 980 822 A1 or EN 10 2015 213 375 A1 basically known in advance.

To interrupt a single phase line, a single-pole circuit breaker is usually used, which usually has a width of one division unit (corresponds to approx. 18mm). For three-phase connections, three-pole circuit breakers are used (as an alternative to three single-pole switching devices), which accordingly have a width of three division units (corresponds to approx. 54mm). Each of the three phase conductors is assigned a pole, i.e. a switching point. If the neutral conductor is to be interrupted in addition to the three phase conductors, these are four-pole devices, which have four switching points: three for the three phase conductors and one for the common neutral conductor. There are also compact circuit breakers, which, with a housing width of just one division unit, provide two switching contacts for each connection line, i.e. either for two phase lines (compact circuit breaker type 1+1) or for one phase line and the neutral conductor (compact circuit breaker type 1+N).

A residual current circuit breaker is a protective device for ensuring protection against a dangerous fault current in an electrical system. A residual current of this type - also known as a differential current - occurs when a live part of a line makes electrical contact with earth. This is the case, for example, when a person touches a live part of an electrical system: in this case, the current flows as a residual current through the body of the person concerned and towards earth. To protect against such body currents, the residual current circuit breaker must quickly and safely disconnect all poles of the electrical system from the power supply when such a residual current occurs. In common parlance, the terms FI circuit breaker (short: FI switch), residual current circuit breaker (short: DI switch) or RCD (for “Residual Current Protective Device”) are used interchangeably instead of the term “residual current circuit breaker”.

Arc fault switches or fire protection switches are used to detect arc faults that can occur at a defective point on an electrical cable - for example, a loose cable clamp or due to a cable break. If the arc fault occurs electrically in series with an electrical consumer, the normal operating current is usually not exceeded because it is limited by the consumer. For this reason, the arc fault is not detected by a conventional overcurrent protection device, such as a fuse or a circuit breaker. To determine whether an arc fault is present, the fire protection switch measures both the voltage curve and the current curve over time and analyzed and evaluated with regard to the characteristic curves of an arc fault. In the (English-language) technical literature, such protective devices for detecting arc faults are referred to as "Arc Fault Detection Device" (abbreviated: AFDD). In North America, the term "Arc Fault Circuit Interrupter" (abbreviated: AFCI) is common.

Furthermore, switching devices without their own protective function are also known from the state of the art. These include, for example, the so-called load switches, isolating switches or load-break switches. The latter are understood to be switching devices which, in terms of their functionality, meet both the requirements of a load switch - switching under electrical load - and the requirements of a isolating switch - the almost power-free disconnection of electrical system components. In low-voltage networks, load-break switches are used, for example, to interrupt main circuits in the main distribution area.

There are also combined device designs in which the functionality of a residual current circuit breaker is supplemented by the functionality of a miniature circuit breaker: such combined protective switching devices are referred to in German as FI/LS or in English as RCBO (for residual current operated circuit-breaker with overcurrent protection). Compared to separate residual current and miniature circuit breakers, these combination devices have the advantage that each circuit has its own residual current circuit breaker: Normally, a single residual current circuit breaker is used for several circuits. If a residual current occurs, all protected circuits are switched off. By using an RCBO, however, only the affected circuit is switched off.

There is a tendency for more and more functions to be integrated into the devices, i.e. combined protective switching devices are being developed which cover the functional scope of several individual devices: in addition to the FI/LS protective switching devices already described above, which combine the functional scope of a conventional residual current circuit breaker (FI) with that of a miniature circuit breaker (LS), there are other designs in which, for example, the functionality of a fire protection switch is integrated into existing devices such as MCB, RCD or RCBO/FILS.

When electrically equipping buildings, a large number of protective switching devices are usually required, which are grouped together in a so-called electrical installation distributor, also known as a distribution box or simply a distributor, and arranged next to one another. The interior of the electrical installation distributor usually contains brackets for structuring the internal structure of the distributor and power supply systems for connecting the electrical and/or electronic components. This also includes the so-called mounting rail or top hat rail, which can be used to easily attach the electrical installation devices in the distribution box by plugging or sliding them on.

The switching devices attached to the mounting rail in the electrical installation distributor have several connection terminals for electrical contact. On the input side (mains side), several switching devices arranged next to each other can be contacted using a busbar. On the output side (load side), the connection terminals are usually designed as screw terminals into which the load-side connection cable is plugged and then clamped by turning a clamping screw.

From the subsequently published disclosure document EN 10 2021 127 154 A1 A contact arrangement for a DIN rail device is known, which has a housing with a first chamber for inserting a first conductor and a second chamber for inserting a second conductor, wherein a first clamping spring for clamping the first conductor is arranged in the first chamber and a second clamping spring for clamping the second conductor is arranged in the second chamber. The contact arrangement also has an actuating element that is movably mounted on the housing between an open position and a closed position, wherein the first clamping spring can be clamped between a first pin of the actuating element and a first axis of the housing in order to clamp a first clamping section of the first clamping spring against the first conductor, and wherein the second clamping spring can be clamped between a second pin of the actuating element and a second axis of the housing in order to clamp a first clamping section of the second clamping spring against the second conductor.

From the subsequently published publication 10 2021 125 902 A1, a connection arrangement for connecting an electrical conductor is known, which has a current bar, a clamping spring with a holding leg and a clamping leg for clamping the conductor to be connected against the current bar, and an actuating arrangement with the aid of which the clamping spring can be transferred from a clamping position to an open position. The actuating arrangement has a first actuating element and a second actuating element which is operatively connected to the first actuating element and the clamping spring, wherein the first and the second actuating element are movable relative to one another.

From the subsequently published disclosure document EN 10 2022 105 570 A1 A connection terminal for an electrical device, for example a DIN rail device, for connecting an electrical conductor and/or a busbar is known. The connection terminal has a connection sleeve along which a pressure piece guided in an adjustment direction can be adjusted between a clamping position and an opening position. The pressure piece is elastically pre-tensioned via a spring element. The pressure piece can be actuated between the clamping position and an opening position using a lever element operatively connected to the pressure piece.

Furthermore, the disclosure document EN 10 2007 016 333 A1 an electrical modular device with a connection terminal is disclosed, which has a first terminal space for inserting an electrical conductor and a second terminal space for inserting a busbar, wherein one and the same compression spring causes both the electrical conductor to be clamped via a pressure piece and the busbar to be clamped via a clamping frame, wherein the clamping frame surrounds an electrical connection piece of the modular device, with which the electrical conductor and the busbar are connected in an electrically conductive manner. An actuating element mounted so as to be rotatable in a housing of the modular device can act on the pressure piece and the clamping frame when rotated in order to open both terminal spaces simultaneously.

Since the available installation space in electrical installation applications - for example in an electrical installation distributor - is usually very limited, it is necessary to make the protective switching devices as compact as possible, for example by using compact "1+N" devices with a width of only one module. Compact protective switching devices with a narrow design are known, for example, from the publication EP 1 473 750 A1 known in principle. Furthermore, the height (e.g. due to a defined row spacing of the mounting rails arranged in the distributor) and the depth (e.g. due to the size of the distribution box) of a protective switching device are subject to normative restrictions: accordingly, the depth of the protective switching device should be a maximum of 70mm and the height of the protective switching device a maximum of 90mm. Furthermore, ever higher nominal currents are to be realized in order to open up further areas of application. All of these developments lead to less and less installation space being available inside the switching devices as the range of functions continues to grow.

It is therefore the object of the present invention to provide a connection terminal and a DIN rail mounted device with such a connection terminal, which are characterized by a wide range of possible uses and simple installation while at the same time being compact in design.

This object is achieved according to the invention by the connection terminal and the modular installation device according to the independent claims. Advantageous embodiments of the connection terminal according to the invention and of the modular installation device according to the invention are the subject of the dependent claims.

The connection terminal according to the invention, for example for a series terminal or a series-mounted device for contacting an external connection conductor, has a clamping frame, a manually operable actuating element rotatably mounted on the clamping frame for opening and closing the connection terminal, a first spring element arranged in the clamping frame, the first end of which is designed to press the external connection conductor that can be inserted into the clamping frame against an electrical connection element that can be arranged in the clamping frame, and a second spring element, the first end of which is operatively connected to the second end of the first spring element and the second end of which is connected to the actuating element. The first spring element has a lower spring hardness than the second spring element.

The connection terminal is compactly designed and can be operated without screws using the actuating element, which makes it much easier to insert the external connection conductor into the front opening of the terminal frame. Due to its compact design, the connection terminal is particularly suitable for use in a compact DIN rail device. The terminal frame of the connection terminal is designed to be accommodated and stored in an insulating housing of the DIN rail device, so that the electrical connection element of the DIN rail device can be inserted from the rear into the terminal frame, which is open at the front and back.

Due to the different spring hardnesses of the first and second spring elements, when the actuating element is moved from an open position to a closed position of the connection terminal, the first spring element is first elastically deformed before the second spring element is elastically deformed. By arranging the first and second spring elements next to one another, the usable stroke of the connection terminal can be increased due to the different spring hardnesses. When the springs are tensioned, i.e. when the actuating element is moved from the open position to the closed position of the connection terminal, the first spring element with the lower spring hardness is initially elastically deformed. If this elastic deformation reaches a predefined maximum spring travel, further deformation of the first spring element is mechanically blocked, whereby - when the actuating element moves further from the open position to the closed position - the second spring element with the higher spring hardness is elastically deformed. The two spring elements therefore act in series, i.e. one after the other in the temporal movement sequence of the actuating element, ensuring that the first spring element is not deformed beyond a maximum permissible spring travel in order to effectively avoid plastic deformation and thus damage to the first spring element due to overstretching.

In an advantageous development of the connection terminal, the second end of the second spring element is rotatably connected to the actuating element. This type of mechanical coupling of the first end of the second spring element with the actuating element allows the kinematics - and thus the spring forces that can be generated by the connection terminal - to be adjusted. In addition, the frictional forces that occur when the connection terminal is actuated are significantly reduced by a rotatable bearing.

In a further advantageous development of the connection terminal, the first end of the second spring element is firmly connected to the second end of the first spring element. The firm connection of the first end of the second spring element to the second end of the first spring element can be achieved, for example, by screwing, riveting, welding, soldering or gluing.

In a further advantageous development of the connection terminal, the first end of the second spring element is connected to the second end of the first spring element via a slide that is slidably mounted in the clamping frame. In this way, the connection terminal can be made even more compact.

In a further advantageous development of the connection terminal, the first end of the second spring element is attached to the slide in a rotatable manner. By selecting the appropriate pivot point of the first end of the second spring element on the slide, the kinematics and thus the spring forces that can be generated by the connection terminal can be adjusted or set. In addition, frictional forces that occur when the connection terminal is actuated are significantly reduced by a rotatable bearing.

In a further advantageous development of the connection terminal, the first spring element and/or the second spring element is designed as a leaf spring. Leaf springs represent a cost-effective embodiment for the first and/or second spring element. However, the invention is not limited to this embodiment: there are a number of other possible embodiments for a spring element which are suitable for use as the first and/or second spring element in the connection terminal according to the invention.

In a further advantageous development of the connection terminal, the first end of the first spring element has a pressure edge which presses into the external connection conductor inserted into the terminal frame when the connection terminal is closed. With the help of the pressure edge, which presses or imprints itself into the external connection conductor, a positive connection between the connection terminal and the connection conductor can be realized, which effectively prevents the external connection conductor from being easily pulled out - for example due to an undesirable tensile load.

In a further advantageous development, the connection terminal has an apron which is slidably mounted on the terminal frame and which can be moved with the actuating element and which, when the connection terminal is closed, covers electrically conductive parts of the connection terminal against manual contact from the outside. In this way, people, for example a person entrusted with installing the DIN rail device, are effectively protected against electric shock.

In a further advantageous development of the connection terminal, the first spring element has a substantially linear spring characteristic. This means that the spring force of the first spring element is substantially proportional to the spring travel when it is stretched or compressed, i.e. it increases constantly with increasing stretching or compression of the first spring element.

In a further advantageous development of the connection terminal, the second spring element has a non-linear spring characteristic. The second spring element is designed in such a way that its spring characteristic is steep at the beginning of the spring travel and flattens out as the spring travel progresses. In other words: the second spring element is hard at the beginning of the spring travel (higher Spring force per unit of travel) and then becomes softer as the travel continues (lower spring force per unit of travel).

The modular device according to the invention, in particular in the form of a compact modular device, has a connection terminal of the type described above for contacting an external connection conductor, which is accommodated and held in an insulating housing of the modular device. The modular device has an electrical connection element which projects into the terminal frame.

While the external connection conductor can be inserted into the front, outward-facing opening of the terminal frame, the electrical connection element is inserted into an opening on the rear of the terminal frame, i.e. one facing the interior of the modular device. With the help of the connection terminal, an easily implemented, mechanically stable, if necessary separable electrical connection is created between the external connection conductor and the electrical connection element of the modular device, which can be operated without tools. With regard to the further advantages of the modular device according to the invention, reference is made to the advantages described above regarding the connection terminal according to the invention.

In an advantageous further development of the DIN rail device, the terminal frame of the connection terminal is mounted so that it can be moved in the insulating housing of the DIN rail device. In this way, external connection conductors with very different conductor cross-sections can also be easily and safely contacted with the connection terminal.

In a further advantageous development of the modular device, the terminal frame has a first receiving space for inserting the external connection conductor on a first side of the electrical connection element facing the first spring element, and a second receiving space, for example for inserting a busbar or another external connection conductor, on a second side facing away from the first spring element. In this way, a busbar can also be easily and safely contacted with the connection terminal - either individually or together with the external connection conductor.

• 1 eine schematische Darstellung zum prinzipiellen Aufbau eines Niederspannungs-Schutzschaltgerätes in einer Seitenansicht;
• 2 eine schematische Darstellung eines ersten Ausführungsbeispiels der erfindungsgemäßen Anschlussklemme in perspektivischer Ansicht;
• 3 und 4 schematische Darstellungen verschiedener Zustände der erfindungsgemäßen Anschlussklemme nach 2, jeweils in einer Seitenansicht;
• 5 eine schematische Darstellung des erfindungsgemäßen Reiheneinbaugerätes mit Anschlussklemme gemäß den 2 bis 5 in perspektivischer Ansicht;
• 6 und 7 schematische Darstellungen eines zweiten Ausführungsbeispiels der erfindungsgemäßen Anschlussklemme in perspektivischer Ansicht;
• 8 bis 11 schematische Darstellungen verschiedener Zustände des zweiten Ausführungsbeispiels der erfindungsgemäßen Anschlussklemme gemäß 6 und 7;
• 12 eine schematische Darstellung einer Anordnung der erfindungsgemäßen Anschlussklemme im Isolierstoffgehäuse des Reiheneinbaugerätes;
• 13 und 14 schematische Darstellungen eines dritten Ausführungsbeispiels der erfindungsgemäßen Anschlussklemme, jeweils in einer Seitenansicht;

In the following, embodiments of the connection terminal are explained in more detail with reference to the attached figures. The figures show:

• 1 a schematic representation of the basic structure of a low-voltage protective switching device in a side view;
• 2 a schematic representation of a first embodiment of the connection terminal according to the invention in a perspective view;
• 3 and 4 schematic representations of different states of the connection terminal according to the invention 2 , each in a side view;
• 5 a schematic representation of the modular device according to the invention with connection terminal according to the 2 to 5 in perspective view;
• 6 and 7 schematic representations of a second embodiment of the connection terminal according to the invention in a perspective view;
• 8 to 11 schematic representations of different states of the second embodiment of the connection terminal according to the invention according to 6 and 7 ;
• 12 a schematic representation of an arrangement of the connection terminal according to the invention in the insulating housing of the DIN rail mounted device;
• 13 and 14 schematic representations of a third embodiment of the connection terminal according to the invention, each in a side view;

In the various figures of the drawing, identical parts are always provided with the same reference symbol. The description applies to all drawing figures in which the corresponding part can also be seen.

In 1 is the basic structure of a low-voltage series-mounted device 1 known from the prior art, more precisely: a low-voltage circuit breaker - shown schematically in a side view (elevation) of one of the broad sides 6, with a front housing cover of the protective switching device 1 being omitted in order to obtain an insight into the interior of the device. The series-mounted device 1 has an insulating housing 2, which in turn has a front side 3, a fastening side 4 opposite the front side 3, as well as narrow sides 5 and broad sides 6 connecting the front side 3 and the fastening side 4. The protective switching device 1 can be fastened to a support or top hat rail (not shown) via the fastening side 4. An actuating element 7 is arranged in the area of the front side 3, with the aid of which the protective Switching device 1 is operated manually, i.e. can be switched on and off.

In the area of the narrow sides 5, an electrical connection terminal designed as a screw terminal is arranged, which forms the input connection or the output connection of the DIN rail device 1. The DIN rail device 1 can be electrically connected to electrical connection conductors (not shown) of the circuit to be monitored via the two screw terminals 8. For this purpose, the screw terminals each have a terminal frame 8 into which the connection conductor to be contacted is inserted. With the help of a clamping screw 9 guided in the terminal frame, the connection conductor is pressed against an electrical connection element of the DIN rail device 1 and thus electrically connected.

Inside the insulating housing 2, the two screw terminals are electrically connected to one another by a current path that can be interrupted by a switching contact 20. To interrupt the current path, the switching contact 20 has a fixed contact 21 and a moving contact 22 that can be moved relative to it. The moving contact 22 is mechanically connected to the actuating element 7 via a switching mechanism of the DIN rail-mounted device 1, so that it can also be opened and closed by means of the actuating element 7.

In 2 a first embodiment of the connection terminal 100 according to the invention is shown schematically in a perspective view. The connection terminal 100 is intended for use in a DIN rail device 1 and serves to establish a mechanically stable, electrically conductive connection with an external connection conductor 50. It has a terminal frame 130 on which a manually operable actuating element 107 for opening and closing the connection terminal 100 is rotatably mounted. The terminal frame 130 is designed in the form of a cuboid that is open at the front and back, so that an electrical connection element 60 of the DIN rail device 1 can be inserted into the terminal frame 130 at the front, into a first receiving space 141 of the connection terminal 100, the external connection conductor 50, and at the back, into a second receiving space 142 of the connection terminal 100. The first connection space 141 is thus located between the first end 111 of the first spring element 110 and the side of the electrical connection element 60 facing the first spring element 110, the second connection space 142 between the side of the electrical connection element 60 facing away from the first spring element 110 and the lower end of the clamping frame 130.

The connection terminal 100 also has a first spring element 110 arranged in the clamping frame 130 with a first end 111 and a second end 112. The first end 111 serves to press the external connection conductor 50 inserted into the front of the clamping frame 130 against the electrical connection element 60 guided at the rear in the clamping frame 130. The first spring element 110 is mechanically operatively connected to the actuating element 107 via a second spring element 120. A first end 121 of the second spring element 120 is mechanically connected to the second end 112 of the first spring element 110 via a slide 135 mounted so as to be displaceable in a vertical direction R1 in the clamping frame 130. In the first embodiment shown here, the second end 112 of the first spring element 110 is rigidly coupled to the slide, while the first end 121 of the second spring element 120 is rotatably coupled. However, this is not mandatory and merely represents one possible variant for coupling the two spring elements 110 and 120. A second end 122 of the second spring element 120 is rotatably coupled to the actuating element 107. It is essential to the invention that the first spring element 110 has a lower spring hardness than the second spring element 120.

In order to effectively prevent contact with live parts of the connection terminal 100, the connection terminal 100 has an apron 136. The apron 136 is made of an insulating material, is mechanically connected to the actuating element 107 and is mounted on the terminal frame 130 so that it can be moved in the vertical direction R1, so that when the connection terminal 100 is closed, live parts of the connection terminal 100 are covered by moving the apron 136.

The 3 and 4 show schematically - each in a side view - different states of the connection terminal 100 according to the invention according to 2 . In 3 is - analogous to the perspective representation in 2 - the connection terminal 100 together with the external connection conductor 50 inserted into the terminal frame and the electrical connection element 60 are shown in an open state. 4 shows the connection terminal 100 in a closed state, wherein additionally a busbar 70 is inserted from the front into the terminal frame 130 below the electrical connection element 60.

When the actuating element 107 is operated clockwise, the connection terminal is released from the 3 shown open state in the 4 shown closed state. During this movement, the Actuating element 107 at the second end 122, a pressure is exerted in the vertical direction R1 by the second spring element 120. If no external connection conductor 50 is inserted into the terminal frame 130 or if the cross-section of the connection conductor 50 is so small that the first end 111 does not touch the connection conductor 50 in the open state, this pressure leads to a displacement of the slide 135 in the vertical direction R1 until the first end of the first spring element 110 hits the external connection conductor 50 or - if no external connection conductor 50 is inserted into the terminal frame 130 - the electrical connection element 60. A further displacement of the slide 135 then leads to a deformation of the first spring element 110, which creates a counterpressure acting against the vertical direction R1, which becomes ever greater with increasing displacement of the slide 135 and thus counteracts its movement in the vertical direction R1.

In order to avoid damage to the first spring element 110 due to excessive deformation, the spring travel of the first spring element 110 is limited by a mechanical stop. A further movement of the actuating element 107 in a clockwise direction then leads to a deformation of the second spring element 120. This increases the pressure on the slide 135 - and thus on the connecting conductor 50 - until a sufficiently high clamping force is achieved so that the connecting conductor 50 is securely clamped between the first end 111 of the first spring element 110 and the electrical connecting element 60. The connecting terminal 100 remains closed because the second spring element 120, when the actuating element 107 rotates in a clockwise direction, i.e. in its closed state, beyond the dead center of the actuating element 107, against a mechanical stop 137 (see 8th ) and thus the actuating element 107 no longer presses back into the open position of the connection terminal 100, but against the mechanical stop 137.

If the connection terminal 100 is mounted in the insulating housing 2 so that it can be moved in the vertical direction R1 (so-called elevator terminal), the terminal frame 130 can be moved in such a way that a busbar 70 can be inserted into the terminal frame 130 from the front below the electrical connection element 60, which is clamped between the connection element 60 and the lower part of the terminal frame 130 when the connection terminal 100 is closed. In addition, the external connection conductor 50 can be inserted into the terminal frame 130 from the front above the connection element 60 and can be securely clamped by closing the connection terminal 100.

In the 2 to 4 In the first embodiment shown, the first spring element 110 consists of two leaf springs which are arranged next to one another transversely to the vertical direction R1. However, this only represents an exemplary embodiment of the first spring element 110.

5 shows a schematic representation of a multi-pole DIN rail mounted device 1 according to the invention, which in the area of its narrow side has several 2 to 4 described connection terminals 100. The connection terminals 100 are arranged next to one another and shown in different states: open, partially closed, completely closed, with and without an external connection conductor 50 plugged in and with and without a busbar 70 plugged in. In order to facilitate the actuation of the actuating element 107, it has a blind hole-like recess into which an actuating lever 108 can be inserted if required. In this way, even with thick external connection conductors 50 and possibly an additionally plugged in busbar 70, large compressive forces can be generated by simple manual actuation.

In the 6 and 7 A second embodiment of the connection terminal 100 according to the invention is shown schematically. Both figures show the connection terminal 100 in the open state - 6 in perspective side view, 7 in a corresponding sectional view. The main difference to the 2 to 4 The difference in the first embodiment shown is the different geometric design of the first spring element 110 and the second spring element 120. The second end 112 of the first spring element 110 is now no longer attached to the underside, but to the top of the slide 135. Furthermore, the second spring element 120 is designed as a folded leaf spring, the second end 122, and thus the coupling to the actuating element 107, being formed by the folding.

• 8 zeigt die Anschlussklemme 100 in einem geöffneten Zustand. In dieser Position ist das erste Ende 111 des ersten Federelements 110 frei, d.h. das erste Ende 111 berührt den externe Anschlussleiter 50 noch nicht, auf das erste Federelement 110 wirkt noch keine mechanische Kraft. Die Dimension des externen Anschlussleiters 50 mit einem Leitungsquerschnitt von 16mm² ist dabei strichliert dargestellt. An einer Seitenwange des Klemmrahmens 130 ist ein mechanischer Anschlag 137 ausgebildet, welcher dazu dient, den Weg des Betätigungselements 107 beim Schließen der Anschlussklemme 110 zu begrenzen. Ferner könnte der mechanische Anschlag 137 auch dazu dienen, das zweite Federelement 120 direkt am Klemmrahmen 130 abzustützen, sodass die Federelement 120 erzeugte Druckkraft im geschlossenen Zustand der Anschlussklemme 100 nicht am Betätigungselement 107, sondern am direkt am Klemmrahmen 130 anliegt.

In the 8 to 11 are again - each in a side view - different states of the 6 and 7 shown second embodiment of the connection terminal 100 according to the invention is shown schematically:

• 8th shows the connection terminal 100 in an open state. In this position, the first end 111 of the first spring element 110 is free, ie the first end 111 does not yet touch the external connection conductor 50, no mechanical force acts on the first spring element 110. The dimension of the external connection conductor 50 with a cable cross-section of 16mm ² is shown in dashed lines. On one side of the clamping frame A mechanical stop 137 is formed on the spring element 130, which serves to limit the path of the actuating element 107 when closing the connection terminal 110. Furthermore, the mechanical stop 137 could also serve to support the second spring element 120 directly on the clamping frame 130, so that the pressure force generated by the spring element 120 does not rest on the actuating element 107, but directly on the clamping frame 130 when the connection terminal 100 is closed.

Above the electrical connection element 60 there is the first receiving space 141 for receiving the external connection conductor 50; below the electrical connection element 60, i.e. on the side of the electrical connection element 60 facing away from the first spring element 110 and oriented towards the lower section of the clamping frame 130, there is the second receiving space 142 for inserting a busbar 70.

In 9 the terminal 100 is shown in a half-open state, ie the actuating element 107 is no longer in the 8th shown open state, but not yet in the state shown in the 10 and 11 shown closed state. In this half-open state, the first spring element 110 has reached its maximum permissible elastic deformation: the first end 111 of the first spring element 110 presses against the external connection conductor 50 with the maximum spring force that can be applied by the first spring element 110. Since the second spring element 120 has a greater spring hardness than the first spring element 110, no elastic deformation of the second spring element 120 has yet occurred in this state. Due to the mechanical coupling with the actuating element 107, the slide 135 was moved downwards in the vertical direction R1, ie in the direction of the electrical connection element 60, via the undeformed second spring element 120 in the clamping frame 130.

The 10 and 11 show the connection terminal 100 with clamped connection conductor 50 in the closed state, in which the actuating element 107 has reached its end position defined by the mechanical stop 137.

10 shows an installation in which a connecting conductor 50 with a small cross-section of 4mm ² is clamped in the first receiving space 141 without a busbar being plugged into the second receiving space 142. This installation represents an extreme case in which the connecting terminal 100 must perform its maximum stroke to clamp the external connecting conductor. The first spring element is advantageously designed in such a way that at least connecting conductors with a small to medium cross-section can be plugged into the first receiving space 141 using plug-in technology, ie without the connecting terminal 100 being plugged into its (in 8th shown) open position, can be inserted directly into the first receiving space 141 (so-called push-in technique). The contours on the movable apron 136 (see 2 ) a user is additionally informed which conductor cross-sections can be inserted using push-in technology. If the contours are too small for the connecting conductor to be inserted, the connecting terminal 100 can be opened using the actuating element 107, whereby the apron 136 is also moved and the first receiving space 141 is exposed.

Even with a small conductor cross-section without a plugged busbar, the shape of the first spring element 110 has changed compared to the 9 shown half-closed state of the connection terminal 100, whereby the first spring element 110 is protected against plastic deformation - and thus against damage - even under higher compressive forces. The clamping pressure required to clamp the external connection conductor 50 results from the elastic deformation of the second spring element 120, whereby a pressure edge formed at the first end 111 of the first spring element 110 is pressed into the external connection conductor 50 so that it is held securely. Unintentional pulling out of the external connection conductor 50 is thus effectively prevented.

In 11 shows another installation in which a connecting conductor with a large cross-section of 16mm ² is clamped in the first receiving space 141, and a busbar 70 is additionally plugged into the second receiving space 142. This installation represents another extreme case in which the connecting terminal 100 has a minimal stroke. Here too, the shape of the first spring element 110 has changed compared to the one in 9 shown half-closed state of the connection terminal 100, so that in this case too the first spring element 110 is protected from damage. The clamping pressure required to clamp the external connection conductor 50 results from a clearly visible elastic deformation of the second spring element 120, which causes the pressure edge formed at the first end 111 to press into the external connection conductor 50.

The spring force applied by the second spring element 120 in the compressed state also acts via the actuating element 107 on the clamping frame 130, which counteracts the vertical is pressed upwards in the direction of R1. In this way, the busbar 70 is pressed by the lower end of the terminal frame 130 against the electrical connection element 60 of the DIN rail device 1.

12 shows a schematic representation of an arrangement of the connection terminal 100 according to the invention in the insulating housing 2 of the DIN rail device 1. For reasons of clarity, only the rear cover of the insulating housing 2, which essentially consists of the rear broad side 6, is shown. The connection terminal 100 is accommodated and held in the insulating housing 2 in the area of the right narrow side 5. In the area of the left narrow side 5, a further connection terminal 100 can be accommodated and held in the insulating housing 2.

The electrical connection element 60 of the DIN rail device 1 is arranged in a fixed position in the insulating housing 2. The spring force applied by the first and second spring elements 110, 120 presses the external connection conductor 50 against the electrical connection element 60 and thus clamps it securely.

In the 13 and 14 A third embodiment of the connection terminal 100 according to the invention is shown schematically, in a side view. Both figures show the connection terminal 100 in the closed state - 13 with plugged connection conductor 50 with small cable cross-section of 4mm ² , 14 with plugged connection conductor 50 with large cable cross-section of 16mm ² and additionally plugged busbar 70.

In contrast to the first two embodiments described above, the connection terminal 100 of the third embodiment does not have a slide to which the first end 111 of the first spring element 110 and the second end 122 of the second spring element 120 are mechanically connected. Instead, the first end 111 of the first spring element 110 is directly and immediately connected to the second end 122 of the second spring element 120 - for example by soldering, welding or riveting.

By arranging several spring elements with different spring hardnesses in a row, the usable spring stroke is increased so that both an external connection conductor with a small cross-section and an external connection conductor with a large cross-section including the inserted busbar can be safely contacted. Due to the different spring hardnesses, the spring element with the lowest spring hardness is elastically deformed first until it has reached its maximum permissible elastic deformation and assumes its harmless end position. The further stroke is then achieved by the next spring element with the higher spring hardness.

The invention is not limited to two spring elements: if necessary, the stroke can be further increased by one or more additional springs arranged in a row. It is important that the spring elements have different spring hardnesses and, after their maximum permissible elastic deformation, assume a harmless position that effectively prevents further loading - and thus damage to the spring element.

List of reference symbols

1

Modular device

2

Insulated housing

3

Front

4

Mounting side

5

Narrow side

6

Broadside

7

Actuator

8th

Clamp frame

9

Clamping screw

20

Switch contact

21

Fixed contact

22

Moving contact

50

external connection conductor

60

electrical connection element

70

Busbar

100

Connection terminal

107

Actuator

108

Operating lever

110

first spring element

111

first end

112

second end

120

second spring element

121

first end

122

second end

130

Clamp frame

135

Sleds

136

apron

137

mechanical stop

141

first recording room

142

second recording room

Claims (13)

Connection terminal (100) for a modular device (1) for contacting an external connection conductor (50), - with a terminal frame (130), - with a manually operable actuating element (107) rotatably mounted on the terminal frame (130) for opening and closing the connection terminal (100), - with a first spring element (110) arranged in the terminal frame (130), having a first and a second end (111, 112), the first end (111) being designed to press the external connection conductor (50) that can be inserted into the terminal frame (130) against an electrical connection element (60) that can be arranged in the terminal frame (130), - with a second spring element (120), the first end (121) of which is operatively connected to the second end (112) of the first spring element (110), and the second end (122) of which is connected to the actuating element (107) is, - wherein the first spring element (110) has a lower spring hardness than the second spring element (120). Connection terminal (100) to Claim 1 , wherein the second end (122) of the second spring element (120) is rotatably connected to the actuating element (107). Connection terminal (100) according to one of the preceding claims, wherein the first end (121) of the second spring element (120) is fixedly connected to the second end (112) of the first spring element (110). Connecting terminal (100) according to one of the Claims 1 until 2 , wherein the first end (121) of the second spring element (120) is connected to the second end (112) of the first spring element (110) via a slide (135) displaceably mounted in the clamping frame (130). Connection terminal (100) to Claim 4 , wherein the first end (121) of the second spring element (120) is rotatably attached to the carriage (135). Connection terminal (100) according to one of the preceding claims, wherein the first spring element (110) and/or the second spring element (120) is designed as a leaf spring. Connection terminal (100) according to one of the preceding claims, wherein the first end (111) of the first spring element (110) has a pressure edge which presses into the external connection conductor (50) inserted into the clamping frame (130) when the connection terminal is closed. Connection terminal (100) according to one of the preceding claims, with an apron (136) which is displaceably mounted on the clamping frame (130), which is movable with the actuating element (107) and covers electrically conductive parts of the connection terminal (100) against contact from the outside when the connection terminal (100) is closed. Connection terminal (100) according to one of the preceding claims, wherein the first spring element (110) has a substantially linear spring characteristic. Connection terminal (100) according to one of the preceding claims, wherein the second spring element (120) has a non-linear spring characteristic. Modular device (1) with a device according to one of the Claims 1 until 10 designed connection terminal (100) for contacting an external connection conductor (50), which is accommodated and held in an insulating housing (2) of the DIN rail mounted device (1), and with an electrical connection element (60) which projects into the terminal frame (130). Modular device (1) according to Claim 11 , wherein the clamping frame (130) of the connection terminal (100) is displaceably mounted in the insulating housing (2). Modular device (1) according to Claim 12 , wherein the clamping frame (130) has a first receiving space (141) for inserting the external connecting conductor (50) on a first side of the electrical connection element (60) facing the first spring element (110) and a second receiving space (142) for inserting a busbar (70) on a second side facing away from the first spring element (110).

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