EP0028389B1 - Low voltage-protective line switch - Google Patents

Low voltage-protective line switch Download PDF

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Publication number
EP0028389B1
EP0028389B1 EP80106618A EP80106618A EP0028389B1 EP 0028389 B1 EP0028389 B1 EP 0028389B1 EP 80106618 A EP80106618 A EP 80106618A EP 80106618 A EP80106618 A EP 80106618A EP 0028389 B1 EP0028389 B1 EP 0028389B1
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EP
European Patent Office
Prior art keywords
contact
movable contact
component
circuit breaker
fixed
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
EP80106618A
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German (de)
French (fr)
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EP0028389A1 (en
Inventor
Lutz Dr. Niemeyer
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
BBC Brown Boveri AG Germany
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BBC Brown Boveri AG Germany
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Publication date
Application filed by BBC Brown Boveri AG Germany filed Critical BBC Brown Boveri AG Germany
Priority to AT80106618T priority Critical patent/ATE5448T1/en
Publication of EP0028389A1 publication Critical patent/EP0028389A1/en
Application granted granted Critical
Publication of EP0028389B1 publication Critical patent/EP0028389B1/en
Expired legal-status Critical Current

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    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01HELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H71/00Details of the protective switches or relays covered by groups H01H73/00 - H01H83/00
    • H01H71/10Operating or release mechanisms
    • H01H71/12Automatic release mechanisms with or without manual release
    • H01H71/122Automatic release mechanisms with or without manual release actuated by blowing of a fuse
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01HELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H71/00Details of the protective switches or relays covered by groups H01H73/00 - H01H83/00
    • H01H71/10Operating or release mechanisms
    • H01H71/12Automatic release mechanisms with or without manual release
    • H01H71/14Electrothermal mechanisms
    • H01H71/145Electrothermal mechanisms using shape memory materials

Definitions

  • the invention relates to a low-voltage circuit breaker with a contact point for each pole consisting of a movable contact piece and a fixed contact piece, with an arc quenching chamber assigned to the contact point, to which contact point an overcurrent release acts in the event of an overload or short-circuit current by means of a switching mechanism, the fixed Contact piece is applied to a guide rail designed simultaneously as an arc guide rail and a clamp connection.
  • Such a circuit breaker is such. B. from DE-A-2 337 058 known.
  • Such circuit breakers are normally designed for specific forward currents or have a specific switching capacity.
  • the switch can be destroyed.
  • contact welds can occur, so that a safe disconnection of the circuit in the event of destruction is no longer guaranteed.
  • a fuse is provided as a predetermined melting point, which can be formed by a wire with a notch.
  • the object of the invention is to further improve the circuit breaker of the type mentioned at the outset.
  • this object is achieved in that the contact point is assigned a component consisting of a shape memory alloy, which deforms when and after its transition temperature is exceeded, thus irreversibly spreading the contact pieces.
  • the invention is to provide additional means in addition to the already existing overcurrent releases, which ensure a safe disconnection even in the event of damage or destruction of the release and also of the switch lock. This separation is said to be irreversible; this is achieved through a one-way shape memory alloy.
  • An advantageous embodiment of the invention can be such that the component is designed in the form of a strip and is attached to the movable contact piece in such a way that its free end lies against a stop fixed to the housing when and after its transition temperature is exceeded and the contact point opens irreversibly by rotating the movable contact piece .
  • the contact point is spread open by turning the movable contact lever, which carries the movable contact piece, in the direction of opening.
  • the component made of the shape memory alloy is attached to the arc guide rail and carries the fixed contact piece in the area of its attachment point.
  • a further embodiment of the invention can be such that the shape memory alloy component is part of the power supply to the fixed contact piece and carries the fixed contact piece, that it moves away from the movable contact piece when and after the transition temperature is exceeded and that it moves in the range of motion of the movable contact piece a stop is provided against which the movable contact piece bears, so that after further deformation of the component, the moving contact piece is prevented from migrating.
  • a shape memory alloy can be used, as is known for example from AT-B-276790, such an alloy being designed as a titanium-nickel alloy and a special martensitic transition at a selected temperature within a desired temperature range has, whereby a so-called mechanical memory or acoustic damping or energy conversion and the like can be achieved.
  • Further memory alloys have become known, for example, from “Journal of applied physics", Volume 39, Number 5, 1968, pages 2195 to 2200.
  • the reference numeral 10 denotes a circuit breaker in base construction, which is approximately T-shaped, wherein in the circuit breaker a switching mechanism 12, a magnetic release 14, a thermal release 16, a contact lever rotatably mounted on an axis 18 20 with a movable contact piece 22 and a fixed contact piece 24 are provided.
  • the fixed contact piece 24 is arranged on an arc guide rail 26, which, viewed downstream, delimits an arc-quenching plate packet 28 with individual arc-quenching plates on the bottom side of the circuit breaker 10.
  • the arc guide rail 26 is connected on the current input side to a connecting terminal 30;
  • a further connection terminal 32 is provided on the current output side, which is connected to the thermal release 16, so that in the switched-on state a current flows from the connection terminal 30 via the contact lever 20, the magnetic release 14 and the thermal release 16 to the other connection terminal 32.
  • the contact lever 20 with the movable contact piece 22 at its end is rotatably supported on its axis 18.
  • a stranded wire not designated by reference numbers, adjoins the contact lever.
  • the movable contact piece is formed by an offset or bend, and it cooperates with the fixed contact piece 24, which is attached to the arc guide rail 26.
  • a strip 42 made of a shape memory material is fastened, which is designed such that it bends in the event of heating in such a way that the movable contact lever 20 is rotated into the position shown in broken lines.
  • the free end of the strip 42 bears against a stop 44 and thereby irreversibly opens the contact point 22/24 by spreading.
  • FIG. 3 shows an arc guide rail 50, which is connected via a strand 52 to an angularly bent component 54 made of shape memory material.
  • the fixed contact piece 24, which again cooperates with the movable contact piece 22, is fastened to the leg 58, to which the strand 52 is connected.
  • the other leg of component 54 is connected to a connecting lug 56 for the connecting terminal.
  • the angular arrangement of the component 54, together with the connecting lug 56 and the guide plate or the arc guide rail 50 forms the same line path as the arc guide rail 26 towards the terminal.
  • the leg 58 spreads into the broken line 58a, as a result of which the contact point 22/24 opens.
  • a further rotation of the movable contact lever 20 is prevented by a stop 60 which corresponds to the stop 44.
  • FIG. 4 shows a further embodiment of the invention in an embodiment similar to that of FIGS. 2 and 3.
  • the arc guide rail 26 which has an offset 62 in the area of the fixed contact piece 24 towards the outside, ie towards the clamp.
  • a strip 63 made of a shape memory material is attached to the bent portion 62 and from it in the direction of the axis 18 of the movable contact lever 20, which practically extends in the extension of the arc guide rail and has a molding 64 serving as a stop at its free end.
  • the strip made of the shape memory alloy bends into the dashed position and in this way spreads the movable contact lever away from the fixed contact piece 24.
  • the molding 64 is of course made of an insulating material.

Landscapes

  • Thermally Actuated Switches (AREA)
  • Breakers (AREA)

Abstract

1. A single- or multi-pole low-tension line circuit breaker with a contact position (22, 24) comprising a movable contact (22) and a fixed contact (24) for each pole, having an arc extinction chamber associated with the contact position (22, 24), on which position by means of a switch mechanism (12) an overcurrent trip acts in the event of an overload current or short circuit current, the fixed contact (24) being mounted on a guide bar which forms both an arc guide bar (26, 50) and a terminal, characterised in that the contact position (22, 24) is associated with a component (42, 58a, 63, 64) which is made from a memory alloy and which is deformed when and after its transition temperature is exceeded and so forces the contacts irreversibly apart.

Description

Die Erfindung betrifft einen Niederspannungs-Leitungsschutzschalter mit einer aus einem beweglichen Kontaktstück und einem festen Kontaktstück bestehenden Kontaktstelle für jeden Pol, mit einer der Kontaktstelle zugeordneten Lichtbogenlöschkammer, auf welche Kontaktstelle mittels eines Schaltmechanismus ein Überstromauslöser im Falle eines Überlast- oder Kurzschlussstromes einwirkt, wobei das feste Kontaktstück auf eine gleichzeitig als Lichtbogenleitschiene und Klemmverbindung ausgebildete Leitschiene aufgebracht ist.The invention relates to a low-voltage circuit breaker with a contact point for each pole consisting of a movable contact piece and a fixed contact piece, with an arc quenching chamber assigned to the contact point, to which contact point an overcurrent release acts in the event of an overload or short-circuit current by means of a switching mechanism, the fixed Contact piece is applied to a guide rail designed simultaneously as an arc guide rail and a clamp connection.

Ein derartiger Leitungsschutzschalter ist z. B. aus der DE-A-2 337 058 bekannt. Derartige Leitungsschutzschalter werden normalerweise auf bestimmte Durchlassströme ausgelegt, beziehungsweise weisen ein bestimmtes Schaltvermögen auf. Jedoch bei bestimmten Überbeanspruchungen im Kurzschluss oder bei fortgesetzten Normalabschaltungen über die in den Prüfvorschriften hinausgehende Schaltzahl kann der Schalter zerstört werden, wobei z. B. Kontaktverschweissungen auftreten können, so dass eine sichere Auftrennung des Stromkreises im Zerstörungsfall nicht mehr gewährleistet ist. Um ein sicheres Auftrennen dennoch zu erreichen, ist eine Sicherung als Sollschmelzstelle vorgesehen, die durch einen Draht mit Kerbstelle gebildet werden kann.Such a circuit breaker is such. B. from DE-A-2 337 058 known. Such circuit breakers are normally designed for specific forward currents or have a specific switching capacity. However, in the event of certain overloads in the short circuit or in the event of continued normal shutdowns beyond the number of switching operations specified in the test regulations, the switch can be destroyed. B. contact welds can occur, so that a safe disconnection of the circuit in the event of destruction is no longer guaranteed. In order to achieve a safe separation, a fuse is provided as a predetermined melting point, which can be formed by a wire with a notch.

Aufgabe der Erfindung ist es, den Leitungsschutzschalter der eingangs genannten Art noch weiter zu verbessern.The object of the invention is to further improve the circuit breaker of the type mentioned at the outset.

Diese Aufgabe wird erfindungsgemäss dadurch gelöst, dass der Kontaktstelle ein aus einer Formgedächtnislegierung bestehendes Bauteil zugeordnet ist, das sich bei und nach Überschreiten seiner Umwandlungstemperatur deformiert und so die Kontaktstücke irreversibel aufspreizt.According to the invention, this object is achieved in that the contact point is assigned a component consisting of a shape memory alloy, which deforms when and after its transition temperature is exceeded, thus irreversibly spreading the contact pieces.

Es ist zwar ein Stromüberlastungsschutz bekannt geworden (DE-A1-2701884), bei dem ein Streifen aus einer Formgedächtnislegierung ähnlich wie ein Thermobimetall zur Schaltung eines Mikroschalters verwendet wird, beziehungsweise das freie Ende eines derartigen Streifens aus einer Formgedächtnislegierung ein bewegliches Kontaktstück aufweist, das mit einem festen Kontaktstück zusammenwirkt; bei beziehungsweise nach Erreichen der Umwandlungstemperatur verformt sich bei der einen Ausführung der Streifen zur Betätigung des Schalters und bei der anderen Ausführung zur Öffnung der Kontaktstelle. Insbesondere bei der letzten Ausführung soll ein Schalter geschaffen werden, der eine Spule und einen dieser zugeordneten Schaltmechanismus nicht mehr aufweist. Der Streifen aus der Formgedächtnislegierung ersetzt somit den thermischen oder magnetischen Überstromauslöser.Current overload protection has indeed become known (DE-A1-2701884), in which a strip made of a shape memory alloy is used to switch a microswitch, similar to a thermobimetal, or the free end of such a strip made of a shape memory alloy has a movable contact piece which is connected to a fixed contact piece cooperates; upon or after reaching the transition temperature, the strips deform in one embodiment for actuating the switch and in the other embodiment for opening the contact point. In the last version in particular, a switch is to be created which no longer has a coil and a switching mechanism assigned to it. The shape memory alloy strip thus replaces the thermal or magnetic overcurrent release.

Bei der Erfindung handelt es sich hingegen darum, zusätzlich zu den schon vorhandenen Überstromauslösern weitere Mittel vorzusehen, die auch im Falle einer Beschädigung oder Zerstörung des Auslösers und auch des Schaltschlosses eine sichere Auftrennung gewährleisten. Diese Auftrennung soll irreversibel sein; dies wird erreicht durch eine Einweg-Formgedächtnislegierung.The invention, on the other hand, is to provide additional means in addition to the already existing overcurrent releases, which ensure a safe disconnection even in the event of damage or destruction of the release and also of the switch lock. This separation is said to be irreversible; this is achieved through a one-way shape memory alloy.

Eine vorteilhafte Ausgestaltung der Erfindung kann dahingehen, dass das Bauteil streifenartig ausgebildet und an dem beweglichen Kontaktstück so angebracht ist, dass es sich mit seinem freien Ende bei und nach Überschreiten seiner Umwandlungstemperatur an einem gehäusefesten Anschlag anlegt und die Kontaktstelle durch Verdrehen des beweglichen Kontaktstückes irreversibel öffnet. Dabei wird die Kontaktstelle bei Überschreitung der Umwandlungstemperatur aufgespreizt, indem der bewegliche Kontakthebel, der das bewegliche Kontaktstück trägt, in Richtung Öffnen verdreht wird.An advantageous embodiment of the invention can be such that the component is designed in the form of a strip and is attached to the movable contact piece in such a way that its free end lies against a stop fixed to the housing when and after its transition temperature is exceeded and the contact point opens irreversibly by rotating the movable contact piece . When the transition temperature is exceeded, the contact point is spread open by turning the movable contact lever, which carries the movable contact piece, in the direction of opening.

Es besteht auch die Möglichkeit, das Bauteil aus der Formgedächtnislegierung an der Lichtbogenleitschiene zu befestigen; dadurch ist es in der Lage, nach Überschreiten der Umwandlungstemperatur das bewegliche Kontaktstück mit seinem freien Ende von dem festen Kontaktstück wegzuspreizen.There is also the possibility of attaching the shape memory alloy component to the arc guide rail; as a result, it is able, after the transition temperature has been exceeded, to spread the free end of the movable contact piece away from the fixed contact piece.

Es besteht ferner die Möglichkeit, dass das Bauteil aus der Formgedächtnislegierung an der Lichtbogenleitschiene befestigt ist und das feste Kontaktstück im Bereich seiner Befestigungsstelle trägt.There is also the possibility that the component made of the shape memory alloy is attached to the arc guide rail and carries the fixed contact piece in the area of its attachment point.

Eine weitere Ausgestaltung der Erfindung kann dahingehen, dass das Bauteil aus der Formgedächtnislegierung Teil der Stromzuführung zu dem festen Kontaktstück ist und das feste Kontaktstück trägt, dass es sich beim und nach dem Überschreiten der Umwandlungstemperatur vom bewegbaren Kontaktstück entfernt und dass in dem Bewegungsbereich des bewegbaren Kontaktstükkes ein Anschlag vorgesehen ist, gegen den sich das bewegbare Kontaktstück anlegt, so dass bei weiterer Verformung des Bauteils ein Nachwandern des beweglichen Kontaktstückes verhindert ist.A further embodiment of the invention can be such that the shape memory alloy component is part of the power supply to the fixed contact piece and carries the fixed contact piece, that it moves away from the movable contact piece when and after the transition temperature is exceeded and that it moves in the range of motion of the movable contact piece a stop is provided against which the movable contact piece bears, so that after further deformation of the component, the moving contact piece is prevented from migrating.

Zur irreversiblen Öffnung des Schalters kann eine Formgedächtnislegierung verwendet werden, wie sie beispielsweise durch die AT-B-276790 bekannt geworden ist, wobei eine derartige Legierung als Titan-Nickel-Legierung ausgebildet ist und einen besonderen martensitischen Übergang bei einer ausgewählten Temperatur innerhalb eines gewünschten Temperaturbereiches aufweist, wodurch ein sogenanntes mechanisches Gedächtnis oder eine akustische Dämpfung oder eine Energieumwandlung und dergleichen erreichbar wird. Weitere Gedächtnislegierungen sind beispielsweise durch «Journal of applied physics», Volume 39, Number 5, 1968, Seiten 2195 bis 2200 bekannt geworden.For the irreversible opening of the switch, a shape memory alloy can be used, as is known for example from AT-B-276790, such an alloy being designed as a titanium-nickel alloy and a special martensitic transition at a selected temperature within a desired temperature range has, whereby a so-called mechanical memory or acoustic damping or energy conversion and the like can be achieved. Further memory alloys have become known, for example, from "Journal of applied physics", Volume 39, Number 5, 1968, pages 2195 to 2200.

Anhand der Zeichnung sollen einige Ausführungsbeispiele der Erfindung näher erläutert und beschrieben werden.Some exemplary embodiments of the invention are to be explained and described in more detail with reference to the drawing.

Sie zeigt:She shows:

  • Fig. 1 eine schematische Darstellung eines Leitungsschutzschalters bei abgenommenem Deckel undFig. 1 is a schematic representation of a Lei circuit breaker with the cover and
  • Fig. 2-4 drei Ausgestaltungen der Erfindung, wobei die irreversible Trennstellung strichliert dargestellt ist.Fig. 2-4 three embodiments of the invention, the irreversible separation position is shown in dashed lines.

In der Fig. 1 ist mit der Bezugsziffer 10 ein Leitungsschutzschalter in Sockelbauweise bezeichnet, der annähernd T-förmig ausgebildet ist, wobei in dem Leitungsschutzschalter ein Schaltmechanismus 12, ein magnetischer Auslöser 14, ein thermischer Auslöser 16, ein an einer Achse 18 drehbar gelagerter Kontakthebel 20 mit einem beweglichen Kontaktstück 22 und ein festes Kontaktstück 24 vorgesehen sind. Das feste Kontaktstück 24 ist auf einer Lichtbogenleitschiene 26 angeordnet, die stromabwärts gesehen auf der Bodenseite des Leitungsschutzschalters 10 ein Lichtbogenlöschblechpaket 28 mit einzelnen Lichtbogenlöschblechen begrenzt. Die Lichtbogenleitschiene 26 ist stromeingangsseitig mit einer Anschlussklemme 30 verbunden; stromausgangsseitig ist eine weitere Anschlussklemme 32 vorgesehen, die mit dem thermischen Auslöser 16 in Verbindung steht, so dass im eingeschalteten Zustand ein Strom von der Anschlussklemme 30 über den Kontakthebel 20, den magnetischen Auslöser 14 und den thermischen Auslöser 16 zur anderen Anschlussklemme 32 fliesst.In Fig. 1, the reference numeral 10 denotes a circuit breaker in base construction, which is approximately T-shaped, wherein in the circuit breaker a switching mechanism 12, a magnetic release 14, a thermal release 16, a contact lever rotatably mounted on an axis 18 20 with a movable contact piece 22 and a fixed contact piece 24 are provided. The fixed contact piece 24 is arranged on an arc guide rail 26, which, viewed downstream, delimits an arc-quenching plate packet 28 with individual arc-quenching plates on the bottom side of the circuit breaker 10. The arc guide rail 26 is connected on the current input side to a connecting terminal 30; A further connection terminal 32 is provided on the current output side, which is connected to the thermal release 16, so that in the switched-on state a current flows from the connection terminal 30 via the contact lever 20, the magnetic release 14 and the thermal release 16 to the other connection terminal 32.

Die Fig. 2 zeigt lediglich die Anordnung im Bereich der Kontaktstelle. Der Kontakthebel 20 mit dem beweglichen Kontaktstück 22 an seinem Ende ist, wie aus der Fig. 1 ersichtlich, an seiner Achse 18 drehbar aufgelagert. An den Kontakthebel schliesst sich eine nicht mit Bezugsziffern bezeichnete Litze an. Das bewegliche Kontaktstück ist durch eine Abkröpfung bzw. Ausbiegung gebildet, und es wirkt mit dem festen Kontaktstück 24 zusammen, das an der Lichtbogenleitschiene 26 befestigt ist. Am freien Ende des beweglichen Kontakthebels 20 ist ein Streifen 42 aus einem Formgedächtnismaterial befestigt, welcher so ausgelegt ist, dass er sich im Falle einer Erwärmung so verbiegt, dass der bewegliche Kontakthebel 20 in die strichliert gezeichnete Lage verdreht wird. Dabei legt sich das freie Ende des Streifens 42 gegen einen Anschlag 44 an und öffnet dadurch die Kontaktstelle 22/24 durch Aufspreizen irreversibel.2 only shows the arrangement in the area of the contact point. The contact lever 20 with the movable contact piece 22 at its end, as can be seen from FIG. 1, is rotatably supported on its axis 18. A stranded wire, not designated by reference numbers, adjoins the contact lever. The movable contact piece is formed by an offset or bend, and it cooperates with the fixed contact piece 24, which is attached to the arc guide rail 26. At the free end of the movable contact lever 20, a strip 42 made of a shape memory material is fastened, which is designed such that it bends in the event of heating in such a way that the movable contact lever 20 is rotated into the position shown in broken lines. The free end of the strip 42 bears against a stop 44 and thereby irreversibly opens the contact point 22/24 by spreading.

Die Fig. 3 zeigt eine Lichtbogenleitschiene 50, die über eine Litze 52 mit einem winkelförmig gebogenen Bauteil 54 aus Formgedächtnismaterial in Verbindung steht. An den Schenkel 58, an dem die Litze 52 angeschlossen ist, ist das feste Kontaktstück 24 befestigt, das wieder mit dem beweglichen Kontaktstück 22 zusammenwirkt. Der andere Schenkel des Bauteiles 54 steht mit einer Anschlussfahne 56 für die Anschlussklemme in Verbindung. Die winkelige Anordnung des Bauteiles 54 bildet zusammen mit der Anschlussfahne 56 und dem Leitblech bzw. der Lichtbogenleitschiene 50 den gleichen Leitungszug wie die Lichtbogenleitschiene 26 hin zur Klemme. Im Falle einer übermässigen Belastung des Schalters durch einen übermässig hohen Kurzschlussstrom oder aus sonstigen Gründen spreizt sich der Schenkel 58 in die strichlierte Linie 58a, wodurch die Kontaktstelle 22/24 sich öffnet. Eine weitere Verdrehung des beweglichen Kontakthebels 20 wird durch einen Anschlag 60 gehindert, der dem Anschlag 44 entspricht.3 shows an arc guide rail 50, which is connected via a strand 52 to an angularly bent component 54 made of shape memory material. The fixed contact piece 24, which again cooperates with the movable contact piece 22, is fastened to the leg 58, to which the strand 52 is connected. The other leg of component 54 is connected to a connecting lug 56 for the connecting terminal. The angular arrangement of the component 54, together with the connecting lug 56 and the guide plate or the arc guide rail 50, forms the same line path as the arc guide rail 26 towards the terminal. In the event of an excessive load on the switch due to an excessively high short-circuit current or for other reasons, the leg 58 spreads into the broken line 58a, as a result of which the contact point 22/24 opens. A further rotation of the movable contact lever 20 is prevented by a stop 60 which corresponds to the stop 44.

Die Fig. 4 zeigt in ähnlicher Ausführung wie die Fig. 2 und 3 eine weitere Ausgestaltung der Erfindung. Man erkennt die Lichtbogenleitschiene 26, die im Bereich des festen Kontaktstückes 24 nach aussen, also in Richtung Klemme hin, eine Abkröpfung 62 aufweist. An der Abkröpfung 62 und von dieser aus in Richtung zu der Achse 18 des bewegbaren Kontakthebels 20 ist ein Streifen 63 aus einem Formgedächtnismaterial befestigt, der praktisch in der Verlängerung der Lichtbogenleitschiene verläuft und an seinem freien Ende als Anschlag dienende Anformung 64 aufweist. Im Falle einer übermässigen Belastung des Schalters durch einen zu hohen Kurzschlussstrom verbiegt sich der Streifen aus der Formgedächtnislegierung in die strichlierte Lage und spreizt auf diese Weise den bewegbaren Kontakthebel von dem festen Kontaktstück 24 ab. Die Anformung 64 ist selbstverständlich aus einem isolierenden Material hergestellt.4 shows a further embodiment of the invention in an embodiment similar to that of FIGS. 2 and 3. One can see the arc guide rail 26, which has an offset 62 in the area of the fixed contact piece 24 towards the outside, ie towards the clamp. A strip 63 made of a shape memory material is attached to the bent portion 62 and from it in the direction of the axis 18 of the movable contact lever 20, which practically extends in the extension of the arc guide rail and has a molding 64 serving as a stop at its free end. In the event of an excessive load on the switch due to an excessively high short-circuit current, the strip made of the shape memory alloy bends into the dashed position and in this way spreads the movable contact lever away from the fixed contact piece 24. The molding 64 is of course made of an insulating material.

Claims (5)

1. A single- or multi-pole low-tension line circuit breaker with a contact position (22, 24) comprising a movable contact (22) and a fixed contact (24) for each pole, having an arc extinction chamber associated with the contact position (22, 24), on which position by means of a switch mechanism (12) an overcurrent trip acts in the event of an overload current or short circuit current, the fixed contact (24) being mounted on a guide bar which forms both an arc guide bar (26, 50) and a terminal, characterised in that the contact position (22, 24) is associated with a component (42, 58a, 63, 64) which is made from a memory alloy and which is deformed when and after its transition temperature is exceeded and so forces the contacts irreversibly apart.
2. A circuit breaker as claimed in claim 1, characterised in that the component (42) is strip- like and is so mounted on the movable contact (22) that It bears with Its free end on a stop (44) fast with the housing when and after Its transition temperature is exceeded and opens the contact position irreversibly due to distortion of the movable contact (22).
3. A circuit breaker as claimed in claim 1, characterised in that the component (63, 64) made from the memory alloy is fixed to the arc guide bar (26) and, with its free end, forces the movable contact (22) away from the fixed contact (24) after the transistion temperature is exceeded.
4. A circuit breaker as claimed in claim 3, characterised in that the component (63, 64) made from the memory alloy is fixed to the arc guide bar (26) and carries the fixed contact (24) in the vicinity of its fixing point.
5. A circuit breaker as claimed in claim 1, characterised in that the component (58a) made from the memory alloy is part of the current path to the fixed contact (24) and carries the fixed contact (24), it moves away from the movable contact (22) when and after the transition temperature is exceeded, and there is provided within range of the movable contact (22) a stop (60) on which the movable contact (22) bears, so that in the event of further deformation of the component (58a) the movable contact (22) cannot follow.
EP80106618A 1979-11-05 1980-10-29 Low voltage-protective line switch Expired EP0028389B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT80106618T ATE5448T1 (en) 1979-11-05 1980-10-29 LOW VOLTAGE CIRCUIT BREAKER.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE2944579A DE2944579C2 (en) 1979-11-05 1979-11-05 Low-voltage circuit breaker
DE2944579 1979-11-05

Publications (2)

Publication Number Publication Date
EP0028389A1 EP0028389A1 (en) 1981-05-13
EP0028389B1 true EP0028389B1 (en) 1983-11-23

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EP80106618A Expired EP0028389B1 (en) 1979-11-05 1980-10-29 Low voltage-protective line switch

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EP (1) EP0028389B1 (en)
JP (1) JPS5673831A (en)
AT (1) ATE5448T1 (en)
DE (1) DE2944579C2 (en)

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DE19727152A1 (en) * 1997-06-26 1999-01-07 Abb Patent Gmbh Residual current circuit breaker

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
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CN104701106B (en) * 2015-03-13 2017-02-01 山东大学 Intelligent element for circuit breaker and preparation method thereof
CN104701107B (en) * 2015-03-17 2016-08-24 山东大学 A kind of circuit fire chopper

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Also Published As

Publication number Publication date
JPS5673831A (en) 1981-06-18
ATE5448T1 (en) 1983-12-15
DE2944579A1 (en) 1981-05-07
DE2944579C2 (en) 1986-02-20
EP0028389A1 (en) 1981-05-13

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