Overcurrent protection device

Abstract

An overcurrent protection device for a circuit to be monitored, includes at least one trigger unit, which is configured for an interruption of the circuit in at least one trigger situation and which comprises at least one conductor section, which is configured for a conduction of a current to be monitored, at least one trigger element, which comprises at least one magnetically and thermally shape-shiftable material and is, in the trigger situation, configured for a thermally-induced and/or magnetically-induced deformation in dependence on a current that flows through the conductor section, and at least one actuation element, which is operatively connected with the trigger element and is configured for a transmission of at least one actuation movement and/or at least one actuation force to at least one interrupter switch.

Claims

1. An overcurrent protection device for a circuit to be monitored, comprising: at least one trigger unit, which is configured for an interruption of the circuit in at least one trigger situation and which comprises at least one conductor section, which is configured for a conduction of a current to be monitored, at least one trigger element, which comprises at least one magnetically and thermally shape-shiftable material and is, in the trigger situation, configured for a thermally-induced and/or magnetically-induced deformation in dependence on a current that flows through the conductor section, and at least one actuation element, which is operatively connected with the trigger element and is configured for a transmission of at least one actuation movement and/or at least one actuation force to at least one interrupter switch, wherein the trigger element comprises at least one magnetic shape-memory alloy, which has a first conversion temperature from a martensitic phase into an austenitic phase and a second conversion temperature from a ferromagnetic phase into a paramagnetic phase, wherein the first and the second conversion temperatures are at least 60° C.

2. The overcurrent protection device as claimed in claim 1, wherein the trigger element is configured for an actuation movement that is sufficient for an actuation of the interrupter switch as a result of at least one thermally-induced shape shift, and is configured for an actuation force that is sufficient for an actuation of the interrupter switch as a result of at least one magnetically-induced shape shift.

3. The overcurrent protection device as claimed in claim 2, wherein the thermally-induced shape shift includes a length change of the trigger element of at least 1.5%.

4. The overcurrent protection device as claimed in claim 2, wherein the magnetically-induced shape shift includes a force generation of at least 1 N per 1 mm.sup.2 of cross-sectional area of the trigger element.

5. The overcurrent protection device as claimed in claim 1, comprising a reset unit having at least one reset element, which is configured for a re-deformation of the trigger element after an occurrence of the trigger situation.

6. The overcurrent protection device as claimed in claim 5, wherein the reset element, observed from the trigger element, is arranged in front of and/or beside the actuation element.

7. The overcurrent protection device as claimed in claim 5, wherein the reset element at least partially encompasses the trigger element.

8. The overcurrent protection device as claimed in claim 5, wherein the reset element comprises at least one compression spring and/or at least one traction spring.

9. The overcurrent protection device as claimed in claim 5, comprising a housing unit, which at least partially houses at least the trigger element and the reset element.

10. The overcurrent protection device as claimed in claim 1, wherein, in the trigger situation, the trigger element is configured for a generation of the actuation force and/or of the actuation movement as a result of a shortening of the trigger element.

11. The overcurrent protection device as claimed in claim 10, wherein the trigger unit is designed in such a way that for the actuation, a deformation is sufficient which includes a shortening of the trigger element by 5% or less.

12. The overcurrent protection device as claimed in claim 1, comprising a transmission unit, which comprises at least one transmission element, which is configured for a transmission of an actuation force and/or actuation movement generated by the trigger element in the trigger situation.

13. The overcurrent protection device as claimed in claim 1, wherein the trigger unit comprises at least one fixed support for the trigger element which, observed from the actuation element, is arranged behind the trigger element.

14. The overcurrent protection device as claimed in claim 1, wherein the conductor section encompasses the trigger element at least section-wise.

15. The overcurrent protection device as claimed in claim 1, wherein the trigger unit comprises at least one ferromagnetic core.

16. The overcurrent protection device as claimed in claim 1, wherein the shape-shiftable material is a magnetic shape-memory alloy, in particular a magnetic shape-memory alloy which contains nickel, manganese, and gallium.

17. The overcurrent protection device as claimed in claim 1, wherein the shape-shiftable material is of monocrystalline design.

18. A system having at least one first overcurrent protection device and having at least one second overcurrent protection device, each as claimed in claim 1, wherein the first overcurrent protection device and the second overcurrent protection device are of the same type, and wherein for a given trigger situation, the first overcurrent protection device displays a different magnetic and/or thermal triggering behavior than the second overcurrent protection device.

19. An overcurrent protection switch, in particular a line circuit breaker, having at least one overcurrent protection device as claimed in claim 1.

Description

DRAWINGS

(1) Further advantages result from the following description of the drawings. Three exemplary embodiments of the invention are illustrated in the drawings. The drawings, the description, and the claims contain numerous features in combination. A person skilled in the art will expediently also consider the features individually and combine them to form further reasonable combinations.

(2) In the figures:

(3) FIG. 1 shows an overcurrent protection device in a schematic sectional illustration,

(4) FIG. 2 shows a schematic stress-strain diagram of a shape-shiftable material of the overcurrent protection device,

(5) FIG. 3 shows a system having the overcurrent protection device and having a second overcurrent protection device in a schematic illustration,

(6) FIG. 4 shows an alternative overcurrent protection device in a schematic sectional illustration, and

(7) FIG. 5 shows a further alternative overcurrent protection device in a schematic sectional illustration.

DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

(8) FIG. 1 shows an overcurrent protection device 10a for a circuit to be monitored in a schematic sectional illustration. The overcurrent protection device 10a is part of an overcurrent protection switch 40a (cf. FIG. 3). The overcurrent protection device 10a is designed in the present case as an automatic circuit breaker device. The overcurrent protection switch 40a is designed in the present case as an automatic circuit breaker.

(9) The overcurrent protection device 10a comprises a trigger unit 12a, which is configured for interrupting the circuit in at least one trigger situation. The trigger situation can comprise a short-circuit situation and/or an overload situation. In particular, the trigger situation comprises a thermal trigger situation, for example the overload situation, and/or a magnetic trigger situation, for example the short-circuit situation. The trigger unit 12a comprises at least one conductor section 14a, which is configured for a conduction of a current to be monitored. In the present case, the current to be monitored flows in the circuit. Furthermore, the trigger unit 12a comprises at least one trigger element 16a, which comprises at least one magnetically and thermally shape-shiftable material 18a. The trigger element 16a is in the trigger situation configured for a thermally-induced and/or magnetically-induced deformation in dependence on a current that flows through the conductor section 14a, in particular in dependence on the current to be monitored. Furthermore, the trigger unit 12a comprises at least one actuation element 20a, which is operatively connected with the trigger element 16a, and which is configured for transmitting at least one actuation movement and/or at least one actuation force to at least one interrupter switch (not shown). In the present case, the interrupter switch is a part of the overcurrent protection switch 40a. However, it is also conceivable that the interrupter switch is part of the overcurrent protection device 10a.

(10) The shape-shiftable material 18a is a thermal and magnetic shape-memory material. The trigger element 16a is formed as thermally and magnetically shape-changing. The trigger element 16a is formed in the present case from the shape-shiftable material 18a. The shape-shiftable material 18a is monocrystalline, wherein a polycrystalline material is also conceivable. The trigger element 16a is formed as a one-piece monocrystal made of the shape-shiftable material 18a in the present case, wherein multipart trigger elements are also conceivable. In the present case, the trigger element 16a can be influenced and in particular deformed by means of a magnetic field and/or a mechanical force and/or a change of a temperature of the trigger element 16a.

(11) In addition, the shape-shiftable material 18a has the property that as a reaction to a mechanical force having a defined minimal strength and a defined direction, a deformation and/or shape shift, which is mechanical in particular, takes place. For a deformation and/or shape shift of the trigger element 16a, in this case an inner force of the trigger element 16a, caused in the present case in particular by a magnetomechanical hysteresis of the shape-shiftable material 18a used, has to be overcome. A movement back into a base shape and/or starting shape also does not automatically occur in this case after a reduction and/or an interruption of the mechanical force and/or a mechanical strain. The trigger element 16a would thus also remain in the present shape in this case, in particular without an external reset stimulus, after the reduction and/or the interruption of the mechanical force and/or the mechanical strain.

(12) FIG. 2 shows a schematic stress-strain diagram of the shape-shiftable material 18a. The stress-strain diagram comprises a tension axis 98a and an expansion axis 100a. The characteristic curves shown and in particular the axial sections thereof are to be understood solely as examples. The shape-shiftable material 18a displays a hysteresis characteristic curve 46a, which characterizes a thermal shape-memory effect of the shape-shiftable material 18a. Furthermore, the shape-shiftable material 18a displays a further hysteresis characteristic curve 48a, which characterizes a magnetic shape-memory effect of the shape-shiftable material 18a. In the diagram, the cases of an elongation (characterized by a direction arrow 50a) and a compression (characterized by a direction arrow 52a) are shown. A greater extension change, in particular a greater lift, can be achieved by means of utilization of the magnetic shape-memory effect, while a greater actuation force can be generated by means of utilization of the thermal shape-memory effect. The two characteristic curves 46a, 48a thus define a usable operation range 54a, which is shown shaded in the diagram. Depending on the embodiment of the thermal and the magnetic shape-memory effect and/or depending on the selection of a shape-shiftable material, the resulting usable operation range can be larger or smaller. In the present case, the shape-shiftable material 18a has a composition such that an elongation of approximately 4% can be generated by means of the thermal shape-memory effect. However, alloys are also conceivable in which a corresponding elongation of 5% or 6% is achievable. Furthermore, the shape-shiftable material 18a has a composition in the present case such that by means of the thermal shape-memory effect, a compression can be generated, proceeding from an elongated state, of approximately 2%. In this case, however, alloys are also conceivable in which a corresponding compression of 3% or 4% is achievable. Furthermore, utilizing the magnetic shape-memory effect for the present shape-shiftable material 18a, a magnetically inducible length change, in particular a compression or an elongation, of approximately 6% is achievable, wherein values of 8% up to 10% or 12% are also conceivable.

(13) As FIG. 1 shows, the trigger element 16a is formed pin-shaped in the present case, in particular having a rectangular cross-sectional area perpendicular to the longitudinal axis 42a. The trigger element 16a comprises a longitudinal axis 42a, which is arranged in parallel to a main extension direction 44a of the trigger element 16a. The trigger element 16a is configured for a length change along its longitudinal axis 42a in the trigger situation. In the present case, the trigger element 16a is in the trigger situation configured for a generation of the actuation force and/or the actuation movement because of a shortening of the trigger element 16a. The shortening is furthermore in the present case a shortening along the longitudinal axis 42a of the trigger element 16a.

(14) In the present case, the trigger element 16a is configured for a generation of an actuation movement that is sufficient for an actuation of the interrupter switch as a result of at least one thermally-induced shape shift and is configured for an actuation force that is sufficient for an actuation of the interrupter switch as a result of at least one magnetically induced shape shift. In particular in the thermal trigger situation, an extension change, in particular the shortening, of the trigger element 16a is sufficient to generate the actuation movement for the interrupter switch. Furthermore, in the magnetic trigger situation, a force generated by the trigger element 16a, in particular acting in parallel to the longitudinal axis 42a of the trigger element 16a, in particular the actuation force, is sufficient for an actuation of the interrupter switch.

(15) The thermally-induced shape shift includes, as mentioned, in the present case a length change of the trigger element 16a, in particular along its longitudinal axis 42a, of at least 1.5%, in particular of approximately 2%, wherein greater values are also conceivable. The length change is furthermore in the present case the shortening of the trigger element 16a. The trigger unit 12a is designed in such a way that a deformation is sufficient for the actuation of the interrupter switch which includes a shortening of the trigger element 16a by at most 5%, in the present case even by at most 2%. A thermally-induced shortening of the trigger element 16a, in particular in the overload situation, is therefore sufficient for an actuation of the interrupter switch.

(16) The magnetically-induced shape shift includes a force generation of at least 1 N per 1 mm.sup.2 of cross-sectional area of the trigger element 16a, in particular perpendicularly to the longitudinal axis 42a of the trigger element 16a. In the present case, the force generation is even at least 2 N per 1 mm.sup.2 of cross-sectional area of the trigger element 16a.

(17) The shape-shiftable material 18a is a magnetic shape-memory alloy, wherein, as mentioned above, other materials are also fundamentally conceivable. In the present case, the shape-shiftable material 18a is a shape-memory alloy, which contains nickel, manganese, and gallium. Furthermore, the trigger element 16a comprises at least one magnetic high-temperature shape-memory alloy in the present case. In particular, the shape-shiftable material 18a is formed as the magnetic high-temperature shape-memory alloy. The magnetic high-temperature shape-memory alloy has in the present case a first conversion temperature from a martensitic phase into an austenitic phase and a second conversion temperature from a ferromagnetic phase into a paramagnetic phase, wherein the first and the second conversion temperatures are at least 60° C., in the present case at least 70° C., wherein higher values of at least 80° C. or 100° C. are also advantageously conceivable.

(18) The overcurrent protection device 10a comprises a transmission unit 28a, which comprises at least one transmission element 30a, which is configured for a transmission of the actuation force and/or actuation movement generated in the trigger situation by the trigger element 16a. In the present case, the transmission element 30a is formed as a lever element, in particular as a double-arm lever. The actuation element 20a, observed from the trigger element 16a, is arranged in front of the transmission element 30a. In the trigger situation, the trigger element 16a contracts, whereby the actuation element 20a is deflected, in particular along the longitudinal axis 42 of the trigger element 16a. The transmission element 30a is pivoted at the same time. It is conceivable that the transmission element 30a is connected directly to the actuation element 20a, wherein a connection can be provided in particular for a transmission of a traction force and/or a pulling movement. However, it is also conceivable that the transmission element 30a applies a pressure force to the actuation element 20a and a movement of the actuation element 20a along the longitudinal axis 42a of the trigger element 16a releases a movement of the transmission element 30a in the trigger situation. The transmission unit 28a is configured to transmit a transmitted actuation movement and a transmitted actuation force to the interrupter switch. It is also conceivable in this case that the transmission element 30a transmits a traction force. It is also conceivable that the transmission element 30a transmits a pressure force.

(19) The trigger unit 12a comprises at least one fixed support 32a, 34a for the trigger element 16a. In the present case, the trigger unit 12a comprises two bearing elements 56a, 58a, which form the fixed supports 32a, 34a. A first fixed support 32a is arranged in front of the trigger element 16a from the actuation element 20a. A second fixed support 34a is arranged behind the trigger element 16a from the actuation element 20a. In the trigger situation, the bearing elements 56a, 58a move toward one another. The fixed supports 32a, 34a support the trigger element 16a on its front faces 68a, 70a. The bearing elements 56a, 58a are arranged opposing along the longitudinal axis 42a of the trigger element 16a, in particular on its front faces 68a, 70a. The trigger element 16a is connected to the bearing elements 56a, 58a. The trigger element 16a can be, for example, adhesively bonded and/or welded onto at least one bearing element 56a, 58a and/or connected thereto in a friction-locked and/or formfitting and/or integrally-joined manner in another way. In the present case, the bearing elements 56a, 58a are formed from non-magnetic iron or another suitable metal, wherein in principle bearing elements made of plastic or ceramic or the like are also conceivable.

(20) The conductor section 14a is configured for a generation of a trigger magnetic field, the field lines of which extend in a region of the trigger element 16a, in particular in a near region of the trigger element 16a and/or inside the trigger element 16a, at least substantially in parallel to its longitudinal axis 42a, in the trigger situation, in particular in the short-circuit situation. A direction 62a of the trigger magnetic field in a near region of the trigger element 16a is schematically shown in FIG. 1.

(21) The conductor section 14a encompasses the trigger element 16a at least section-wise. In the present case, the conductor section 14a comprises a coil 60a, within which the trigger element 16a is arranged. The coil 60a extends multiple times around the trigger element 16a. A longitudinal axis 64a of the coil 60a is arranged at least substantially in parallel to the longitudinal axis 42a of the trigger element 16a. The coil 60a is configured for a generation of the trigger magnetic field. In particular, the longitudinal axes 42a, 64a of the coil 60a and the trigger element 16a are identical. In the present case, the coil 60a is formed as an air coil. In particular, the trigger unit 12a is free of an iron core or another magnetic flux conduction element in the present case.

(22) The overcurrent protection device 10a comprises a reset unit 22a having at least one reset element 24a, which is configured for a re-deformation of the trigger element 16a after an occurrence of the trigger situation. The reset element 24a is formed in the present case as a compression spring. The reset element 24a is arranged between the bearing elements 56a, 58a. The bearing elements 56a, 58a are part of the reset unit 22a in the present case. During the re-deformation, the reset element 24a presses the bearing elements 56a, 58a apart from one another along the longitudinal axis 42a of the trigger element 16a and generates in particular a reset force for the re-deformation of the trigger element 16a. The reset element 24a is configured for exerting an elongation force on the trigger element 16b for the re-deformation. During the re-deformation, the trigger element 16a is elongated and in particular transferred into an elongated starting state.

(23) The reset element 24a at least partially encompasses the trigger element 16a. In the present case, the reset element 24a defines an inner region, within which the trigger element 16a is arranged. In particular, a longitudinal axis 66a of the reset element 24a and the longitudinal axis 42a of the trigger element 16a are arranged in parallel to one another and in particular are identical. The reset element 24a extends in multiple turns around the trigger element 16a.

(24) The reset element 24a, observed from the actuation element 20a, is arranged adjacent to the trigger element 16a. The trigger element 16a and the reset element 24a, observed from the transmission element 30a, are arranged behind the actuation element 20a. The trigger element 16a is arranged at least section-wise inside the reset element 24a.

(25) The overcurrent protection device 10a comprises a housing unit 26a, which at least partially houses at least the trigger element 16a and the reset element 24a. In the present case, the housing unit 26a is formed from a material which is heat resistant and/or has good thermal conductivity, for example from a non-magnetizable metal or a suitable plastic or the like. In particular, the housing unit 26a is configured for a heat transfer from the conductor section 14a to the trigger element 16a, in particular in the thermal trigger situation. It is also fundamentally conceivable that a housing unit is formed at least partially from a magnetic and/or magnetizable material and forms, for example, at least one magnetic flux conduction element, such as an iron core in particular.

(26) In the present case, the housing unit 26a defines an accommodation space 72a for the trigger element 16a. The trigger element 16a, the fixed supports 32a, 34a and the reset element 24a are arranged inside the accommodation space 72a. Moreover, the actuation element 20a is partially arranged inside the accommodation space 72a. In the trigger situation, an outer surface of the accommodation space 72a forms a slide bearing for the bearing element 56a, which moves along the longitudinal axis 42a of the trigger element 16a toward the stationary bearing element 58a. In particular, the bearing element 58a is fixed in place in relation to the housing unit 26a. The housing unit 26a forms a feedthrough 80a for the actuation element 20a, which can in particular at least partially guide the actuation element 20a. In the trigger situation, because of the shortening of the trigger element 16a, the actuation element 20a is drawn and/or pressed through the feedthrough 80a at least farther than in a starting state into the accommodation space 72a. Furthermore, in the present case, the housing unit 26a defines an accommodation region 74a for the conductor section 14a. The coil 60a is arranged inside the accommodation region 74a. The coil 60a extends around the accommodation space 72a. The housing unit 26a forms a coil body for the coil 60a.

(27) FIG. 3 shows a system 76a having the overcurrent protection device 10a and having a second overcurrent protection device 38a in a schematic illustration. The overcurrent protection device 10a is, as mentioned, part of an overcurrent protection switch 40a. The second overcurrent protection device 38a is part of a second overcurrent protection switch 78a. The overcurrent protection device 10a and the second overcurrent protection device 38a are of the same type. For example, the second overcurrent protection device 38a could be installed instead of the overcurrent protection device 10a in the overcurrent protection switch 40a. In the present case, the overcurrent protection switch 40a and the second overcurrent protection switch 78a are at least externally structurally equivalent and/or usable alternatively in relation to one another, for example in corresponding fuse slots of a fuse box.

(28) For a given trigger situation, for example for a specific overcurrent and/or short-circuit current, which is applied over a specific time frame, the overcurrent protection device 10a displays a different magnetic and/or thermal triggering behavior than the second overcurrent protection device 38a. For example, the second overcurrent protection device 38a can differ from the overcurrent protection device 10a with respect to a number of coil turns of a conductor section, a geometry of a trigger element, a material of a trigger element, a geometry and/or a material of a housing unit, a presence of an iron core, and the like. For example, by way of a use of components having a high heat capacity, a thermal triggering can be delayed or suppressed. Furthermore, for example, by way of an attenuation of a generated magnetic field, for example by a reduction of a number of windings of a coil, a limiting current required for triggering can be set. Furthermore, it is conceivable that a triggering behavior is adaptable by means of suitable adaptation of a geometry of a transmission unit.

(29) Two further exemplary embodiments of the invention are shown in FIGS. 4 and 5. The following descriptions and the drawings are substantially restricted to the differences between the exemplary embodiments, wherein with regard to identically denoted components, in particular with respect to components having identical reference signs, reference can also be made in principle to the drawings and/or the description of the other exemplary embodiments, in particular to FIGS. 1 to 3. To differentiate the exemplary embodiments, the letter a follows the reference signs of the exemplary embodiment in FIGS. 1 to 3. In the exemplary embodiments of FIGS. 4 and 5, the letter a is replaced by the letters b and c.

(30) FIG. 4 shows an alternative overcurrent protection device 10b for a circuit to be monitored in a schematic sectional illustration. The alternative overcurrent protection device 10b is part of an overcurrent protection switch (not shown), for example a fuse, in particular an automatic circuit breaker.

(31) The alternative overcurrent protection device 10b comprises a trigger unit 12b, which is configured for interrupting the circuit in at least one trigger situation. The trigger situation can comprise a short-circuit situation and/or an overload situation. In particular, the trigger situation comprises a thermal trigger situation, for example the overload situation, and/or a magnetic trigger situation, for example the short-circuit situation. The trigger unit 12b comprises at least one conductor section 14b, which is configured for a conduction of a current to be monitored. In the present case, the current to be monitored flows in the circuit. Furthermore, the trigger unit 12b comprises at least one trigger element 16b, which comprises at least one magnetically and thermally shape-shiftable material 18b. In the present case, the shape-shiftable material 18b is a magnetic and thermal shape-memory material. The trigger element 16b is in the trigger situation configured for a thermally-induced and/or magnetically-induced deformation in dependence on a current that flows through the conductor section 14b, in particular in dependence on the current to be monitored. Furthermore, the trigger unit 12b comprises at least one actuation element 20b, which is operatively connected with the trigger element 16b and is configured for a transmission of at least one actuation movement and/or at least one actuation force to at least one interrupter switch (not shown). In the present case, the interrupter switch is a part of the overcurrent protection switch. However, it is also conceivable that an interrupter switch is part of the alternative overcurrent protection device 10b.

(32) The conductor section 14b is in the present case configured for a generation of a trigger magnetic field, the field lines of which extend at least in a near region of the trigger element 16b and/or inside the trigger element 16b at least substantially perpendicularly to a longitudinal axis 42b of the trigger element 16b, in the trigger situation. A direction 62b of the trigger magnetic field in the near region of the trigger element 16b is schematically shown in FIG. 4. In the present case, the conductor section 14b is formed at least section-wise as a coil. In particular, the conductor section 14b forms at least two opposing coils, so that the trigger magnetic field permeates the trigger element 16b as homogeneously as possible perpendicularly to the longitudinal axis 42b.

(33) The trigger unit 12b comprises at least one magnetic flux conduction element 82b. In the present case, the trigger unit 12b comprises a ferromagnetic core 36b, in particular an iron core. The ferromagnetic core 36b is configured for an amplification of the trigger magnetic field. In the present case, the ferromagnetic core 36b comprises two pole shoes 84b, 86b, which are in particular arranged opposite. One coil formed by the conductor section 14b is associated with each of the pole shoes 84b, 86b.

(34) In the present case, a shape shift of the trigger element 16b in the trigger situation comprises an expansion along its longitudinal axis 42b, in particular a thermally-induced and/or magnetically-induced expansion. In this case, in particular in the thermal trigger situation, a comparatively greater lift is advantageously achievable as a result of a thermally-induced expansion than in the case of a thermally-induced compression, in particular similarly to the embodiment shown in FIGS. 1 to 3. In the present case, the trigger element 16b is configured in the thermal trigger situation for a length change, in particular an elongation, of approximately 4%. Furthermore, the trigger element 16b is configured in the magnetic trigger situation for a length change, in particular an elongation, of approximately 6%. In this case, however, other values are also conceivable depending on the selection of suitable shape-shiftable materials, in particular magnetic and thermal shape-memory alloys. In the present case, a length change of the trigger element 16b by approximately 4% is sufficient for an actuation of the interrupter switch.

(35) The trigger unit 12b comprises a fixed support 32b for the trigger element 16b. The fixed support 32b supports a front face 70b of the trigger element 16b facing away from the actuation element 20b and is in particular connected thereto in a friction-locked and/or integrally-joined and/or formfitting manner. Upon a generation of the actuation movement and/or the actuation force, the trigger element 16b expands, proceeding from the fixed support 32b, in the direction of the actuation element 20b and pushes it along the longitudinal axis 42b of the trigger element 16b away from the fixed support 32b.

(36) The alternative overcurrent protection device 10b comprises a reset unit 22b having a reset element 24b. The reset element 24b, observed from the trigger element 16b, is arranged beside the actuation element 20b. The actuation element 20b passes section-wise through the reset element 24b. The reset element 24b encompasses the actuation element 20b at least section-wise. The reset element 24b is formed as a compression spring. The reset unit 22b comprises a bearing element 88b for the reset element 24b. A position of the bearing element 88b in relation to the fixed support 32b is constant. During the re-deformation, the bearing element 88b generates a counter retaining force for the reset element 24b. The bearing element 88b is formed ring-shaped in the present case. The actuation element 20b passes through the bearing element 88b. The actuation element 20b comprises a counter element 90b, against which the reset element 24b presses during the re-deformation. The counter element 90b is formed collar-shaped in the present case. A reset pressure force of the reset element 24b is transmitted during the re-deformation via the actuation element 20b onto the trigger element 16b.

(37) FIG. 5 shows a further alternative overcurrent protection device 10c for a circuit to be monitored in a schematic sectional illustration. The further alternative overcurrent protection device 10c is part of an overcurrent protection switch (not shown), for example, a fuse, in particular of an automatic circuit breaker.

(38) The further alternative overcurrent protection device 10c comprises a trigger unit 12c, which is configured for an interruption of the circuit in at least one trigger situation. The trigger situation can comprise a short-circuit situation and/or an overload situation. In particular, the trigger situation comprises a thermal trigger situation, for example the overload situation, and/or a magnetic trigger situation, for example the short-circuit situation. The trigger unit 12c comprises at least one conductor section 14c, which is configured for a conduction of a current to be monitored. In the present case, the current to be monitored flows in the circuit. Furthermore, the trigger unit 12c comprises at least one trigger element 16c, which comprises at least one magnetically and thermally shape-shiftable material 18c. The trigger element 16c is in the trigger situation configured for a thermally-induced and/or magnetically-induced deformation in dependence on a current that flows through the conductor section 14c, in particular in dependence on the current to be monitored. Furthermore, the trigger unit 12c comprises at least one actuation element 20c, which is operatively connected with the trigger element 16c, and which is configured for a transmission of at least one actuation movement and/or at least one actuation force to at least one interrupter switch (not shown). In the present case, the interrupter switch is a part of the overcurrent protection switch. However, it is also conceivable that an interrupter switch is part of the further alternative overcurrent protection device 10c.

(39) The conductor section 14c is in the present case configured, in the trigger situation, for the generation of a trigger magnetic field, the field lines of which extend at least in a near region of the trigger element 16c and/or inside the trigger element 16c at least substantially perpendicularly to a longitudinal axis 42c of the trigger element 16c. A direction 62c of the trigger magnetic field in the near region of the trigger element 16c is schematically shown in FIG. 5. In the present case, the conductor section 14c is formed at least section-wise as a coil. The conductor section 14c forms a coil 92c. The coil 92c encompasses the trigger element 16c transversely to its longitudinal axis 42c. The coil 92c is partially arranged inside the actuation element 20c. The actuation element 20c forms an accommodation space 96c, which partially accommodates the first coil 92c. The coil 92c is arranged partially in front of the trigger element 16c and partially behind the trigger element 16c from the actuation element 12c. The coil 92c is configured for the generation of the trigger magnetic field in such a way that its field lines extend at least substantially in parallel to the direction 62c in the trigger situation.

(40) In the present case, the trigger unit 12c is free of a magnetic flux conduction element and in particular free of an iron core. The conductor section 14c forms at least one air coil in the present case. In particular, the coil 92c is formed as an air coil.

(41) The further alternative overcurrent protection device 10c comprises a reset unit 22c having a reset element 24c. The reset element 24c is formed as a traction spring. The reset element 24c is, observed from the trigger element 16c, arranged in front of the actuation element 20c. The reset element 24c is configured for the generation of a compression force on the trigger element 16c for a re-deformation thereof, in particular at least substantially in parallel to the longitudinal axis 42c of the trigger element 16c.

(42) The reset element 24c is connected to bearing elements 56c, 58c for the trigger element 16c. A first bearing element 56c is connected to the actuation element 20c and/or is formed thereby. A second bearing element 58c forms a fixed support 32c for the trigger element 16c. The second bearing element 58c supports a front face 70c of the trigger element 16c facing away from the actuation element 20c. For the re-deformation, the reset element 24c pulls the bearing elements 56c, 58c toward one another, whereby the compression force acting on the trigger element 16c is generated.