CN108631075B

CN108631075B - Connecting terminal

Info

Publication number: CN108631075B
Application number: CN201810214381.1A
Authority: CN
Inventors: A.M.埃尔哈特; D.格鲁斯; M.泰格特; C.海因茨
Original assignee: Phoenix Contact GmbH and Co KG
Current assignee: Phoenix Contact GmbH and Co KG
Priority date: 2017-03-15
Filing date: 2018-03-15
Publication date: 2021-01-19
Anticipated expiration: 2038-03-15
Also published as: CN108631075A; DE102017105554A1

Abstract

The invention relates to a connection terminal having a housing, at least one terminal element, at least one current bar, a protective element and an electrically conductive spring element, a first terminal of the protective element being electrically conductively connected to the at least one terminal element, a first end section of the electrically conductive spring element being electrically conductively connected to the at least one current bar, a thermally decoupled connection between a second end section of the electrically conductive spring element and a second terminal of the protective element being decoupled in the event of a predetermined limit temperature of the protective element being exceeded, the second end section of the electrically conductive spring element being moved into a position in which it is spaced apart from the second terminal of the protective element on the basis of a spring force of the spring element, at least one recess being formed in the current bar, the first end section of the electrically conductive spring element having at least one Z-shaped tongue, the tongue extends from the upper side of the current bar through the recess to the lower side of the current bar, so that the free end of the tongue rests on the lower side of the current bar.

Description

Connecting terminal

Technical Field

The invention relates to a terminal with a housing, at least one terminal element, at least one current bar, a protective element and an electrically conductive spring element, wherein a first terminal of the protective element is electrically conductively connected to the at least one terminal element. The first end section of the electrically conductive spring element is electrically conductively connected to the at least one current bar, while the second end section of the spring element is electrically conductively connected to the second terminal of the protective element in the normal state of the protective element via a thermally separate connection. In the event of exceeding a predetermined limit temperature of the protective element, the thermally decoupled connection between the second end section of the spring element and the second connection of the protective element is decoupled, so that the second end section of the spring element is moved, on the basis of the spring force of the spring element, into a position in which it is spaced apart from the second connection of the protective element. The protective elements are then electrically separated.

Background

Terminals have been known for decades and are used millions of times in the wiring of electrical installations and devices. The terminals are often latched on a carrier rail, which can itself be arranged in large numbers in the switchgear cabinet. In addition, however, the terminal block can also be fastened individually or in multiple pieces as a terminal block in a wall opening of a housing wall, in particular in an opening in a switchgear cabinet wall.

The electrical connection terminal is often a connection terminal, so that it has at least two terminal elements, which are usually connected to one another in an electrically conductive manner by means of a current bar arranged in the terminal housing. In the case of connecting terminals, screw terminals, tension spring terminals or torsion spring terminals are used in most cases as connecting elements. In addition to the basic type of connecting terminals, which is often also referred to as feedthrough terminals, there are a number of different terminal types which are specifically adapted to the respective application. The protection conductor terminal, the separation terminal, and the mounting terminal are mentioned as examples.

Furthermore, terminals exist in which, in addition to the terminal element and the at least one current bar, additional electrical or electronic components are arranged in the housing. The protective element can be, in particular, an overvoltage-limiting component, such as a varistor, a diode or a gas-filled overvoltage leadthrough, with which the connected lines and signal paths are protected against overvoltage. Such terminals then have the function of overvoltage protection devices and are widely used, in particular, in measurement, control and calibration technology.

For monitoring the state of the protective element it is known: the protective element is connected to the terminal element by a thermally separate connection. What is ensured by the thermal separation site is: the protective element is electrically disconnected in the event of impermissible heating. DE 4241311C 2 discloses, for example, an overvoltage protection element which has a thermal disconnection device for monitoring the state of a varistor. In this overvoltage protection element, the first terminal is connected via a flexible conductor to a rigid separating element, and the end of the separating element facing away from the flexible conductor is connected via a soldering point to a terminal lug provided on the varistor. The further terminal is firmly connected to a second connection tab on the varistor by means of a flexible conductor. The electrically conductive connecting element is loaded by a spring system with forces which result in: the connecting element moves linearly away from the connecting lug when the soldering points are separated, so that the varistor is electrically disconnected in the event of a thermal overload.

DE 69503743T 2 discloses an overvoltage protection element with two varistors, which has two electrically conductive connecting elements, by means of which the varistors can each be individually separated at the end of their operating life. The connecting elements are each designed as an elastic separating tongue, wherein a first end of the separating tongue is integrally connected or soldered to the first terminal contact, and a second end of the separating tongue is fastened to a connecting tongue on the varistor by means of a soldering point in the normal state of the overvoltage protection element. This leads to melting of the soldered connection if an inadmissible heating of the varistor results. Since the separating tongue is deflected out of its rest orientation in the soldered state and is therefore pretensioned, the free end of the separating tongue springs away from the coupling tongue of the varistor when the soldered connection softens, as a result of which the varistor is electrically separated.

In connection terminals with corresponding protective elements, it is also known to provide: in order to monitor the protective element, an elastic separating tongue is used, which is connected at one end to the connection of the protective element by means of a soldering point as a thermally separate connection. The other end of the separating tongue is firmly soldered either to the connection of the printed circuit board or to the current bar, which in each case means an increase in the production expenditure. The following are also problematic: such connecting terminals should have increasingly smaller dimensions, in particular smaller widths, which additionally makes mounting difficult.

Disclosure of Invention

The object of the present invention is therefore to provide a terminal described at the outset which can be produced with the least possible outlay and therefore also with little outlay. The mounting of the connection terminals should be as simple as possible and preferably largely automatable.

This object is achieved in the connecting terminal according to the invention in that: at least one recess is formed in the current bar, and the first end section of the electrically conductive spring element has at least one Z-shaped tongue which extends from the upper side of the current bar through the recess in the current bar to the lower side of the current bar in such a way that a free end of the tongue rests on the lower side of the current bar.

In the connection terminal according to the invention, the connection between the electrically conductive spring element and the current bar is thus not produced by a relatively complex soldering process, but rather by a form-locking connection between the current bar and the electrically conductive spring element, so that the spring element can be fastened to the current bar by a purely mechanical mounting step. In order to ensure the necessary firm and reliable connection between the spring element and the current bar, the spring element is fixed to the current bar by means of at least one Z-shaped tongue, which is also able to receive the forces and moments generated by the deflection of the spring element from its rest orientation. For this purpose, a tongue extending in the longitudinal direction of the current bar passes through a recess in the current bar, wherein the spring element is clamped on the current bar by the tongue.

The current bar preferably has a projection, for example produced by die casting, in the first end section of the spring element a recess corresponding to the projection is formed, into which the projection engages in the mounted state of the current bar and the spring element. By means of the projections and the recesses, which are preferably each of rectangular or square design, a defined positioning and orientation of the spring element relative to the current bar, i.e. not only in the direction of the longitudinal extent of the current bar but also transversely thereto, can be ensured in a simple manner.

Since the spring element is mostly made of a harder material than the current bar, it is generally simpler to construct the projections on the current bar and the recesses on the spring element, which are produced, for example, by stamping. However, in principle, it is also possible to replace: the first end section of the electrically conductive spring element has a projection, and a corresponding recess is formed in the current bar, into which the projection engages in the mounted state of the current bar and the spring element. In this case, a reliable and unambiguous positioning of the spring element relative to the current bar is also ensured by the interaction of the projections and the recesses.

In order to be able to achieve the simplest possible fastening of the spring element on the current bar, according to a preferred embodiment of the invention the recess in the current bar is open towards the edge of the current bar and the recess in the first end section of the spring element is open towards the opposite edge of the spring element. It is thereby possible to: the spring element is moved with its end section onto the current bar perpendicular to the longitudinal extent of the current bar during installation. The recess in the spring element is thereby moved laterally onto the projection in the current bar and the tongue is guided into the laterally open recess in the current bar. For the mounting, only a single-axis mounting movement perpendicular to the longitudinal extension of the current bar and therefore generally also perpendicular to the plane of the connection terminal is necessary, which enables a simple automatability of the mounting.

According to an advantageous embodiment, the current bar has a chamfer in the region where the free end of the tongue rests on the underside, said chamfer transitioning from the longitudinal side to the underside. Thereby, it becomes easy for the spring element or tongue to move onto the current bar. In particular, a simple, gap-free mounting of the spring element on the current bar is thereby also possible, for which purpose, according to a further advantageous embodiment, a press fit is realized between the Z-shaped tongue of the first end section of the electrically conductive spring element and the current bar. The spacing between the upper side of the tongue and the lower side of the spring element is therefore slightly smaller than the thickness of the current bar. A secure and stable fastening of the spring element on the current bar is therefore also ensured by the press fit.

In the previously described embodiment of the invention, exactly one recess is formed on the current bar, and the first end section of the spring element also has only one Z-shaped tongue in correspondence with the recess. According to an alternative embodiment of the connection terminal according to the invention, two recesses are formed in the current bar, which recesses are opposite one another, and the first end section of the electrically conductive spring element has two Z-shaped tongues arranged parallel to one another for the recesses. The two tongues each extend from the upper side of the current bar to the lower side of the current bar via the recess, so that the free ends of the tongues rest against the lower side of the current bar.

In this embodiment variant, the first end section of the spring element and the current bar are designed mirror-symmetrically with respect to their respective longitudinal axis at least in the region in which the two components are connected to one another. This has the following advantages: a twisting in the connecting region is avoided, so that a firm and durable connection of the spring element and the current bar can be achieved.

In this embodiment variant, the current bar preferably also has a projection, in the end section of the spring element a recess corresponding to the projection being formed, into which the projection engages in the mounted state of the spring element and the current bar. In order to also maintain the previously described symmetry, the projections and the recesses are each configured or arranged symmetrically with respect to the center plane of the current bar and the first end section of the spring element.

According to a further advantageous embodiment of the connecting terminal according to the invention, the upper side of the current bar and/or the lower side of the first end section of the electrically conductive spring element has a dot-shaped or linear elevation, for example a groove, a rib or a die-cast part. This results in a reduced contact surface between the spring element and the current bar. This advantageously results in an improved surface contact in the non-positive contact between the spring element and the current bar, which results in a lower transition resistance between the two components. This is advantageous because the spring element serves not only to separate the protective element in the elastic case, but also to pass through the spring element and the current bar a surge current or overcurrent which is derived when the protective element responds. For this purpose, a good electrical connection between the first end section of the spring element and the current bar with as low a transition resistance as possible is advantageous.

At the beginning, the following are carried out: at least one recess is formed in the current bar, and the first end section of the electrically conductive spring element has at least one Z-shaped tongue. According to an alternative embodiment of the invention, the arrangement of the recess and the tongue can also be changed, so that at least one recess is formed in the first end section of the electrically conductive spring element, and the current bar has a Z-shaped tongue. The tongue extends here in the mounted state through the recess to the upper side of the spring element, so that the free end of the tongue rests on the upper side of the spring element.

In an alternative embodiment of the invention, the Z-shaped tongues are therefore formed on the current bar, for which purpose the tongues are correspondingly punched out of the current bar and bent. The tongue here preferably also extends in the longitudinal direction of the current bar and is arranged centrally with respect to the width of the current bar. The recess in the first end section of the spring element can be produced simply by stamping. The mounting of the current bar and the spring element can be realized particularly simply in the following manner: the recess of the spring element is open towards the edge of the spring element, so that the spring element can be moved onto the current bar perpendicular to the longitudinal extent of the current bar when mounted. The Z-shaped tongue extends through the recess, wherein in the mounted state a free end of the tongue rests on the upper side of the spring element.

In this case, a press fit is preferably realized between the Z-shaped tongue of the current bar and the first end section of the spring element, so that the spring element is reliably clamped on the current bar by the tongue. In order to facilitate the displacement of the spring element onto the current bar or the displacement of the first end section of the spring element under the tongue of the current bar, a chamfer is preferably formed on the tongue, which transitions from the longitudinal side to the underside.

According to an advantageous embodiment of the second alternative of the invention, the current bar additionally has a projection, in which a recess corresponding to the projection is formed in the first end section of the electrically conductive spring element, into which recess the projection engages in the installed state. In order to be able to realize a single-axis mounting movement in this embodiment, the recess in the spring element is open at the edge facing the current bar in the mounting direction, so that the spring element can be moved onto the current bar perpendicular to the longitudinal extent of the current bar during mounting.

In order to ensure a precise positioning of the spring element on the current bar, a stop can be formed on the upper side of the current bar, against which a first end section of the electrically conductive spring element rests with its end face. In this embodiment, it is then possible to dispense with the formation of a recess in the first end section of the spring element.

In the connection terminal according to the invention, the electrically conductive spring element is preferably designed as a bent leaf spring, i.e. as a leaf spring which is initially subjected to bending, irrespective of whether the at least one Z-shaped tongue is arranged on the spring element or on the current bar. The spring element is here shaped in the following manner: the first end section of the spring element extends parallel to the current bar in the installed state. Furthermore, a bent or C-shaped intermediate section is arranged between the first end section and the second end section. Since the middle section of the spring element is not straight, but rather is C-shaped or bent, the following possibilities are provided: the spring element can also be used in only a small available installation space, and it has a sufficient length, so that the spring force of the spring element, which is necessary for a reliable release, can be ensured without exceeding the extension limit of the spring element.

If the electrically conductive spring element has a bent middle section according to the first embodiment variant, the middle section preferably has two lateral edges which are arranged at an angle α to one another. The angle α is formed here as an acute angle, preferably less than 75 °, in particular less than 65 °. Depending on the available installation space for the spring element, the angle α between the two sides of the bent middle section can be, for example, between 50 ° and 60 °.

If the spring element has a bent middle section, the first end section and the second end section of the spring element are also each arranged at an angle to the adjacent side of the middle section of the spring element. The angle β between the first end section of the spring element and the first side of the middle section is configured here as an obtuse angle, preferably greater than 110 °, in particular greater than 125 °. The angle β can be selected or determined to adjust the prestress with which the spring element is deflected out of the starting rest position when the second end section of the spring element is connected to the second connection of the protective element by a thermally separate connection.

According to a further advantageous embodiment of the connecting terminal according to the invention, the distance a between the transition from the first end section to the middle section of the electrically conductive spring element and the Z-shaped tongue is as large as possible, so that a lever arm is present between the point of placement of the spring element on the current bar and the region on which the spring element is fastened to the current bar. The distance a is at least as large as the width of the current bar. Bending of the current bar or the spring element, which is caused by the bending moment on the fastening point in the current bar weakened by the recess, which is formed by the spring force, is thereby prevented.

According to a last advantageous embodiment of the connection terminal according to the invention, which will also be explained briefly here, a display element is arranged movably in the housing of the connection terminal, which display element interacts with the second end section of the electrically conductive spring element in the following manner: the display element is located in the display position when the second end section of the electrically conductive spring element is spaced apart from the second connection of the protective element by the separate thermal connection. If the thermal connection between the second end section of the spring element and the second connection of the protective element is separated on the basis of an inadmissible heating of the protective element, this results in: the second end section of the spring element springs away from the second connection of the protective element.

If the second end section of the spring element is now connected to the receiving or fastening region of the display element, a movement of the second end section of the spring element results in a corresponding movement of the display element, which can be used in a simple manner to indicate the released state of the protective element. For this purpose, for example, a window is formed in the housing of the connection terminal, through which the display surface of the display element is visible when the display element is brought into its display position by the spring-back of the spring element. The display element is preferably brought from the first position into the display position by a purely linear movement. In order to reliably ensure that the display element is always moved into its display position in the case of a separate thermal connection, the spring element is constructed in the following manner: when the display element is in the display orientation, the spring element is then also slightly deflected out of its rest orientation. The display element is thereby also held securely in the display position with a certain spring force.

Drawings

There are now many possibilities for designing and improving the connection terminal according to the invention in detail. Reference is made to the preferred embodiments for this purpose and the ensuing description of the embodiments with reference to the accompanying drawings. In the drawings:

fig. 1 shows a side view of a terminal according to the invention with an attached protective element and an electrically separated protective element;

fig. 2 shows a first embodiment of a spring element fastened to a current bar in a perspective view;

fig. 3 shows an enlarged view of the connection region of the spring element and the current bar according to fig. 2 in a perspective view, from the side and from above;

fig. 4 shows an enlarged view of a variant of the first embodiment of the spring element fastened to the current bar according to fig. 2 in a perspective view and from the side;

fig. 5 shows a second embodiment of a spring element fastened to a current bar in a perspective view;

fig. 6 shows an enlarged view of the connection region of the spring element and the current bar according to fig. 5 in a perspective view, from the side and from above;

fig. 7 shows a third embodiment of a spring element fastened to a current bar in a perspective view;

fig. 8 shows an enlarged view of the connection region of the spring element and the current bar according to fig. 7 in a perspective view, from the side and from above; and is

Fig. 9 shows a perspective view of a further variant of the first exemplary embodiment of a spring element fastened to a current bar according to fig. 2.

Detailed Description

Fig. 1 shows an exemplary embodiment of a terminal 1 according to the invention from the side. The terminal 1 has a housing 2 made of plastic, in which two

terminal elements

3, 4 are arranged on two planes, wherein the

terminal elements

3, 4 of one plane are connected to each other by means of a

current bar

5, 6. In the housing 2 of the connecting terminal 1, a protective element 7, which is in the present case a varistor, and an electrically conductive spring element 8 are furthermore arranged. The first terminal 7a of the protective element 7 is connected to the two upper terminal elements 3 via the upper current bar 6. The electrical connection of the first terminal 7a of the protective element 7 to the terminal element 3 is not necessarily realized by a current bar. Instead of the current bar 6, a flexible conductor or conductor track of the circuit board can also be used to electrically connect the first terminal 7a of the protective element 7 to at least one of the two terminal elements 3.

The electrically conductive spring element 8 serves for electrically coupling the second terminal 7b of the protective element 7. For this purpose, first of all, the first end section 9 of the spring element 8 is electrically conductively connected to the lower current bar 5. Furthermore, the second end section 10 of the spring element 8 is electrically connected to the second connection 7b of the protective element 7 in the normal state of the protective element 7 by means of a thermally separate connection 11. The connection 11, which is the thermal separation of the respective solder, is constructed in the following manner: when the protective element 7 exceeds a predetermined limit temperature, the solder melts and thus the connection 11 is separated. This then results in: the spring element 8, which is deflected out of its rest orientation, springs back, wherein the second end section 10 of the spring element 8 is distanced from the second tab 7b of the protective element 7, so that the protective element 7 is electrically separated.

The two previously described states, namely the normal state of the protective element 7, in which the two

terminals

7a, 7b are in electrical contact, and the electrically separated protective element 7, in which the second terminal 7b is no longer connected to the second end section 10 of the spring element 8, are shown in fig. 1a (normal state) and fig. 1b (separated state).

In the exemplary embodiment of a terminal 1 according to the invention shown in fig. 1, the housing 2 also has mounting feet 12, with which the terminal 1 can be fastened to a carrier rail 13. Furthermore, a metallic terminal element 14 is arranged in the housing 2 of the connection terminal 1, by means of which the lower current bar 5 is electrically connected in the latched state to the carrier rail 13. If the carrier rail 13 is at ground potential, the electrical connection of the second terminal 7b of the protective element 7 to ground potential can also be realized only by the spring element 8, the current bar 5 and the terminal element 14, so that the lower terminal element 4 is not absolutely necessary. In general practice, the two

current bars

5, 6 are still connected at their ends to the

terminal elements

3, 4, respectively, as is shown in fig. 1. The

terminal elements

3, 4 for connecting the electrical conductors can be screw terminals as is the case in the present case. However, it is equally well possible to use further terminal elements, for example, tension spring terminals or torsion spring terminals.

Fig. 2 shows an embodiment of a spring element 8 fastened to a current bar 5 in a perspective view. Fig. 3 shows an enlarged view of the fastening or connecting region of the current bar 5 and the spring element 8 from the side (fig. 3 b) and from above (fig. 3 c) in a perspective view (fig. 3 a). Fig. 4 to 9 show further embodiment variants of the connection of the current bar 5 and the spring element 8. Common to all the exemplary embodiments is here: the connection between the electrically conductive spring element 8 and the current bar 5 is not produced by means of a complex welding or soldering connection, but rather by means of a positive and non-positive connection, so that the spring element 8 can be fastened to the current bar 5 by a purely mechanical mounting process.

In the first exemplary embodiment according to fig. 2 and 3, a recess 15 is formed in the current bar 5, through which a Z-shaped tongue 16 extends, which is stamped out of the first end section 9 of the spring element 8 and is bent. As can be seen in particular from the enlarged view according to fig. 3a, the tongue 16 extends from the upper side of the current bar 5 through the recess 15 to the lower side of the current bar 5, where the free end 17 of the tongue 16 rests. Furthermore, the current bar 5 has a rectangular projection 18, in which a recess 19 is formed in the first end section 9 of the spring element 8, said recess corresponding to the projection, into which recess the projection 18 engages. By the interaction of the projections 18 and the recesses 19, the spring element 8 is securely fixed in its position and orientation relative to the current bar 5, wherein the removal of the first end section 9 of the spring element 8 from the current bar 5 is prevented by the Z-shaped tongues 16 that move into the recesses 15.

Furthermore, not only from the perspective views according to fig. 2 and 3a, but also from the top view according to fig. 3c, are seen: the recess 15 in the current bar 5 is open towards the (front) edge of the current bar 5. Furthermore, the recess 19 in the spring element 8 is open toward the opposite (rear) edge of the spring element 8, so that the spring element 8 can be moved with its first end section 9 onto the current bar 5 perpendicular to the longitudinal extent L of the current bar 5 during installation. The mounting direction M is drawn in fig. 3c for illustration purposes.

In order to prevent the risk of a possible slight tilting of the spring element 8 on the current bar 5, a press fit is achieved between the tongue 16 of the spring element 8 and the current bar 5. The distance between the upper side of the free end 17 of the tongue 16 and the lower side of the first end section 9 of the spring element 8 is therefore slightly smaller than the thickness of the current bar 5. In this case, therefore, although the displacement of the first end section 9 of the spring element 8 or the displacement of the tongue 16 into the recess 15 can be effected simply and without warping, the region of the current bar 5, in which the free end 17 of the tongue 16 rests on the underside, has a chamfer 20 which transitions from the longitudinal side of the current bar 5 to the underside.

Fig. 4 shows an enlarged view of a variant of the fastening of the spring element 8 and the current bar 5 according to fig. 2 in a perspective view (fig. 4 a) and from the side (fig. 4 b). In this exemplary embodiment, the current bar 5 also has a recess 15, through which a Z-shaped tongue 16 formed on the first end section 9 of the spring element 8 extends. Furthermore, a projection 18 is formed on the upper side of the current bar 5, which engages in a recess 19 in the first end section 9 of the spring element 8. In contrast to the exemplary embodiment according to fig. 2 and 3, a bulge 21 is formed on the underside of the spring element 8, as a result of which a reduced contact surface is formed between the current bar 5 and the spring element 8. In the exemplary embodiment shown, the elevations 21 are realized by means of ribs introduced into the spring element 8. Alternatively, corresponding projections, for example grooves, which extend perpendicularly to the longitudinal extension L of the current bar 5, can also be provided on the upper side of the current bar 5.

Fig. 5 shows a second exemplary embodiment of a spring element 8 fastened to a current bar 5 in a perspective view. An enlarged view of the connection region of the current bar 5 and the spring element 8 is shown in fig. 6, i.e. in a perspective view (fig. 6 a), from the side (fig. 6 b) and from above (fig. 6 c). The obvious difference between the first embodiment shown in fig. 2 to 4 and the second embodiment shown in fig. 5 and 6 is that: two recesses 15, 15 'which are opposite one another are formed in the current bar 5, and the first end section 9 of the spring element 8 has two Z-shaped tongues 16, 16' which are arranged parallel to one another. The two tongues 16, 16' each extend from the upper side of the current bar 5 through the recesses 15, 15' to the lower side of the current bar, where the free ends 17 of the tongues 16, 16' rest against the lower side of the current bar 5.

In this embodiment variant, the mounting of the spring element 8 on the current bar 5 is not effected by a lateral displacement, but by an inward pivoting of the first end region 9 of the spring element 8, for which purpose the free ends 17, 17' of the tongues 16, 16' are first inserted from above into the recesses 15, 15', and subsequently the spring element 8 is pivoted in the clockwise direction in the arrangement according to fig. 5. In this case, the projection 18 formed on the upper side of the current bar 5 engages in a recess 19 formed in the first end section 9 of the spring element 8, as a result of which the spring element 8 is fixed precisely in its position and orientation on the current bar 5.

Here, not only from the perspective views according to fig. 5 and 6a, but also from the top view according to fig. 6c, are seen: in this embodiment variant, the current bar 5 and the first end section 9 of the spring element 8 are configured mirror-symmetrically to the center plane of the current bar 5 or the spring element 8 in the connecting region. Furthermore, the two Z-shaped tongues 16, 16' are designed to reliably prevent the spring element 8 from twisting relative to the current bar 5. However, the mounting of the spring element 8 is more complicated than in the embodiment variant according to fig. 2 to 4, since the fastening cannot be established by a simple linear mounting movement.

Fig. 7 shows a third embodiment variant of the connection of current bar 5 and spring element 8, which differs from the previously described embodiment variants in that: in this case, a recess 22 is formed in the first end section 9 of the spring element 8, and the current bar 5 has a Z-shaped tongue 23. The tongue 23 here extends through the recess 22 in the following manner: so that the free end 24 of the tongue 23 rests on the upper side of the spring element 8. Since the recess 22 in the first end section 9 of the spring element 8 is open towards the (rear) edge of the spring element 8, the mounting can also be effected here simply by laterally moving the spring element 8 onto the current bar 5. In this case, the middle region of the Z-shaped tongue 23 slides into the recess 22, while at the same time the region of the first end section 9 of the spring element 8 adjacent to the recess 22 moves below the free end 24 of the tongue 23.

Here, too, a press fit between the Z-shaped tongue 23 and the first end section 9 of the spring element 8 can be achieved, as a result of which the spring element 8 is reliably clamped on the current bar 5. The chamfer formed on the tongue 23 can facilitate the insertion of the end section 9 of the spring element 8. A stop 25 is additionally formed on the upper side of the current bar 5, which serves as a rotation prevention for the spring element 8. Furthermore, the stop 25 also facilitates a precise and tolerance-free positioning of the spring element 8 on the current bar 5 when the first end section 9 of the electrically conductive spring element 8 rests with its end face 26 on the stop 25.

Fig. 9 shows a further variant of the first exemplary embodiment of a spring element 8 fastened to a current bar 5. In the exemplary embodiment according to fig. 2, but also in the exemplary embodiment according to fig. 9, and in further exemplary embodiments, the spring element 8 is also designed as a curved leaf spring, which is stamped out of a corresponding elastic material and is curved. In the exemplary embodiment according to fig. 1 to 6, a bent middle section 27 is arranged between the first end section 9 and the second end section 10, which extend parallel to the current bar 5 in the installed state. In contrast, in the exemplary embodiment according to fig. 7 to 9, a C-shaped intermediate section 28 is formed between the first end section 9 and the second end section 10 of the spring element 8. Depending on the specific shape and design of the

intermediate sections

27, 28, it is thus possible to realize a spring element 8 which, even in a limited installation space, has a sufficient length in order to provide the necessary spring force which is necessary in order to reliably and safely spring the second end section 10 of the spring element 8 away from the second connection 7b of the protective element 7 when the limit temperature of the protective element 7 is reached.

In the embodiment according to fig. 2, the middle section 27 of the spring element 8 has two

side edges

29, 30 which are arranged at an angle α to each other, wherein the angle α is approximately 55 ° in the embodiment shown. The angle β between the first end section 9 and the first side 29 of the middle section 27 is about 135 °. By selecting the angle β, the deflection path can be adjusted in a simple manner in order to deflect the second end section 10 out of the rest position of the spring element 8 when the second end section is connected to the second connection 7b of the protective element 7 by means of the thermally separate connection 11. If the angle β is reduced in otherwise the same size, this results in: in the normal state of the protective element 7, the spring element 8 is deflected further, so that a greater prestressing force acts on the thermally decoupled connection 11.

As can be seen from fig. 2, the first side 29 of the middle section 27 is not directly adjacent to the connection region of the first end section 9 of the spring element 8. In contrast, a distance a exists between the first lateral edge 29 of the center section 27 and the foot point of the Z-shaped tongue 16. The distance a is preferably at least as large as the width of the current bar 5. This results in a lever arm between the connection region of the spring element 8 and the current bar 5 and the placement point 31 of the spring element 8, so that the forces and bending moments occurring in the connection region of the first end section 9 on the basis of the spring force of the spring element 8 are reduced. It is thereby ensured that: no bending of the current bar 5 is caused in the weakened region on the basis of the recess 15. The first end section 9 of the spring element 8 has the same width as the current bar 5, whereby the spring element 8 can be supported laterally on the housing 2 in this region. The second end section 10 of the spring element 8, on the other hand, has a smaller width, so that the second end section 10 is not prevented by lateral contact with the housing 2 when the spring element 2 springs back.

In the connection terminal 1 according to the invention, the soldering of the two components can be dispensed with due to the positive and non-positive connection between the current bar 5 and the spring element 8, but independently of this, the connection between the second connection 7b of the protective element 7 and the second end connection 10 of the spring element 8 is effected by means of a soldering point as a thermally separate connection 11. In order to make the soldering point well accessible during installation, the webs 32 are bent laterally on the second end section 10 of the spring element 8, wherein the angle between the webs 32 and the second end section 10 is approximately 90 °. The configuration of the bent tab 32 furthermore has the following advantages: thereby, a certain tolerance compensation with respect to the positioning of the second joint 7b of the protection element 7 is possible. Different protective elements 7 with slightly deviating dimensions can thus also be used.

As can be seen from the illustration of the connection terminal 1 according to the invention in fig. 1, a display element 33 is movably arranged in the housing 2 of the connection terminal 1, by means of which display element the user can be explained: the thermally separated connection 11 has been separated and thus the protective element 7 is electrically separated. For this purpose, the free end of the second end section 10 of the spring element 8 engages in a corresponding receptacle 34 on the display element 33, so that the display element 33 is moved into its display position by the spring element 8 when the spring element 8 springs back. In the display position shown in fig. 1b, the preferably color-characterizing display surface 35 of the display element 33 is located below a viewing window formed in the housing 2, so that the state of the protective element 7 (coupled or uncoupled) is easily recognizable to the user.

Claims

1. A terminal (1) having a housing (2), at least two terminal elements (3, 4), at least one current bar (5, 6), a protective element (7) and an electrically conductive spring element (8),

wherein a first terminal (7 a) of the protective element (7) is electrically conductively connected to at least one terminal element (3),

wherein a first end section (9) of the electrically conductive spring element (8) is electrically conductively connected to the at least one current bar (5), wherein a second end section (10) of the electrically conductive spring element (8) is electrically conductively connected to a second connection (7 b) of the protective element (7) by a thermally separate connection (11) in the normal state of the protective element (7), and

wherein, in the event of exceeding a predetermined limit temperature of the protective element (7), a thermally separate connection (11) between the second end section (10) of the electrically conductive spring element (8) and the second connection (7 b) of the protective element (7) is separated, and the second end section (10) of the electrically conductive spring element (8) is moved, on the basis of the spring force of the spring element (8), into a position in which the second end section (10) is spaced apart from the second connection (7 b) of the protective element (7),

it is characterized in that the preparation method is characterized in that,

at least one recess (15) is formed in the current bar (5), and the first end section (9) of the electrically conductive spring element (8) has at least one Z-shaped tongue (16) which extends from the upper side of the current bar (5) through the recess (15) to the lower side of the current bar (5), so that a free end (17) of the tongue (16) rests on the lower side of the current bar (5).

2. Connection terminal (1) according to claim 1, characterized in that the current bar (5) has a projection (18) and a corresponding recess (19) is formed in the first end section (9) of the electrically conductive spring element (8), into which recess the projection (18) engages, or in that the first end section (9) of the electrically conductive spring element (8) has a projection and a corresponding recess is formed in the current bar (5), into which recess the projection engages.

3. A connection terminal (1) according to claim 2, characterised in that the recess (15) in the current bar (5) is open towards an edge of the current bar (5) and the recess (19) in the first end section (9) of the electrically conductive spring element (8) is open towards the opposite edge of the spring element (8), so that the spring element (8) can be moved with its first end section (9) onto the current bar (5) perpendicular to the longitudinal extension (L) of the current bar (5) when mounted.

4. A terminal (1) according to claim 3, characterised in that the region of the current bar (5) in which the free end (17) of the tongue (16) rests against the underside has a chamfer (20) which transitions to the underside.

5. A terminal (1) according to claim 1 or 2, characterized in that two mutually opposite recesses (15, 15 ') are formed in the current bar (5), and the first end section (9) of the electrically conductive spring element (8) has two Z-shaped tongues (16, 16 ') arranged parallel to one another, which extend from the upper side of the current bar (5) through the recesses (15, 15 ') to the lower side of the current bar (5) in each case, so that the free ends (17, 17 ') of the tongues (16, 16 ') rest on the lower side of the current bar (5).

6. A terminal (1) according to claim 1, characterised in that a press fit is achieved between the at least one Z-shaped tongue (16, 16') of the first end section (9) of the electrically conductive spring element (8) and the current bar (5).

7. A terminal (1) according to claim 1, characterised in that the upper side of the current bar (5) and/or the lower side of the first end section (9) of the electrically conductive spring element (8) has a dot-shaped or linear elevation (21), so that a reduced contact surface is formed between the spring element (8) and the current bar (5).

8. A terminal (1) having a housing (2), at least two terminal elements (3, 4), at least one current bar (5, 6), a protective element (7) and an electrically conductive spring element (8),

it is characterized in that the preparation method is characterized in that,

at least one recess (22) is formed in the first end section (9) of the electrically conductive spring element (8), and the current bar (8) has a Z-shaped tongue (23) which extends through the recess (22) onto the upper side of the electrically conductive spring element (8) such that a free end (24) of the tongue (23) rests on the upper side of the spring element (8).

9. A terminal (1) according to claim 8, characterised in that the current bar (5) has a stop (25) against which the first end section (9) of the electrically conductive spring element (8) rests with its end face (26).

10. A connection terminal (1) according to claim 1 or 8, characterised in that the electrically conductive spring element (8) is configured as a bent leaf spring, the first end section (9) of the spring element (8) extends parallel to the current bar (5), and a bent middle section (27) is arranged between the first end section (9) and the second end section (10) of the spring element (8).

11. Terminal (1) according to claim 10, with a bent-over central section (27), characterized in that the central section (27) has two lateral edges (29, 30) which are arranged at an angle α to one another, wherein the angle α is an acute angle.

12. A connection terminal (1) according to claim 10, characterised in that the first end section (9) of the electrically conductive spring element (8) and the first side (29) of the intermediate section (27) are arranged at an angle β to each other, wherein the angle β is an obtuse angle.

13. A terminal (1) according to claim 11 or 12, characterised in that the distance a of the transition from the first end section (9) to the middle section (27) of the electrically conductive spring element (8) from the Z-shaped tongue (16) of the spring element (8) or from the Z-shaped tongue (23) of the current bar (5) is as large as possible.

14. A terminal (1) according to claim 1 or 8, characterised in that a laterally bent tab (32) is arranged on the second end section (10) of the electrically conductive spring element (8), wherein a thermally separate connection (11) is arranged between the second terminal (7 b) of the protective element (7) and the tab (32).

15. A connection terminal (1) according to claim 1 or 8, characterised in that the second end section (10) of the electrically conductive spring element (8) interacts with a display element (33) arranged movably in the housing (2) in the following manner: the display element (33) is positioned in the display position when the second end section (10) of the electrically conductive spring element (8) is spaced apart from the second connection (7 b) of the protective element (7) by the separate connection (11).

16. A connection terminal (1) according to claim 1 or 8, characterised in that the electrically conductive spring element (8) is configured as a bent leaf spring, the first end section (9) of the spring element (8) extends parallel to the current bar (5), and a C-shaped middle section (28) is arranged between the first end section (9) and the second end section (10) of the spring element (8).