(19)
(11)EP 2 747 113 B1

(12)EUROPEAN PATENT SPECIFICATION

(45)Mention of the grant of the patent:
21.10.2015 Bulletin 2015/43

(21)Application number: 12008485.0

(22)Date of filing:  20.12.2012
(51)International Patent Classification (IPC): 
H01H 33/66(2006.01)
H01H 33/666(2006.01)
H01H 1/58(2006.01)

(54)

Circuit-breaker pole part with a flexible conductor for connecting a movable electrical contact

Polteil eines Schutzschalters mit einem flexiblen Leiter zum Verbinden eines bewegbaren elektrischen Kontakts

Partie polaire de disjoncteur avec conducteur flexible pour relier un contact électrique mobile


(84)Designated Contracting States:
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

(43)Date of publication of application:
25.06.2014 Bulletin 2014/26

(73)Proprietor: ABB Technology AG
8050 Zürich (CH)

(72)Inventors:
  • Gentsch, Dietmar
    40882 Ratingen (DE)
  • Sauer, Manfred
    40885 Ratingen (DE)

(74)Representative: Schmidt, Karl Michael 
ABB AG GF-IP Oberhausener Strasse 33
40472 Ratingen
40472 Ratingen (DE)


(56)References cited: : 
EP-A1- 2 063 442
US-A1- 2009 218 319
  
      
    Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention).


    Description

    Field of the invention



    [0001] The invention relates to a pole part of a circuit-breaker arrangement comprising an insulation housing for accommodating a vacuum interrupter insert containing a pair of corresponding electrical contacts, wherein a fixed upper electrical contact is connected to an upper electrical terminal, molded or assembled in the insulation housing and a movable lower electrical contact is connected to a flexible conductor comprising a first end for attaching the flexible conductor to the lower electrical terminal and a second end for attaching the electrical conductor to the movable lower electrical contact.

    [0002] Furthermore, the present invention relates to a circuit-breaker arrangement for medium-voltage applications comprising at least one of such pole parts.

    Background of the invention



    [0003] A circuit-breaker pole part is usually integrated in medium-voltage to high voltage circuit-breaker arrangement. Especially, medium-voltage circuit-breakers are rated between 1 and 72kV of a high current level. These specific breakers interrupt the current by creating and extinguishing the arc in a vacuum container. Inside the vacuum container a pair of corresponding electrical switching contacts is accommodated. Modern vacuum circuit-breakers attend to have a longer life expectancy than former air circuit-breakers. Allthough, vacuum circuit-breakers replace air circuit-breakers, the present invention is not only applicable to vacuum circuit-breakers but also for air circuit-breakers or modern SF6 circuit-breakers having a chamber filled with sulfurhexafluoride gas instead of vacuum.

    [0004] For actuating a circuit-breaker, usually a magnetic or a spring actuator with a high force density is used which moves one of the electrical contacts of a vacuum interrupter for a purpose of electrical power interruption. Therefore, a mechanical connection between a movable armature of a spring or magnetic actuator and an axially movable electrical contact inside the vacuum interrupter is provided.

    [0005] The document EP 2 063 442 A1 discloses a circuit-breaker pole part comprising a pair of corresponding electrical switching contacts which are partly accommodated inside a interrupter filled with sulfurhexafluride gas for high voltage applications above 52kV of a high current above 10kA.

    [0006] Document US2009/218319 discloses a device according to the preamble of claim 1.

    [0007] According to the common knowledge of a skilled person it is also possible to attach a flexible conductor of the kind as described above by screwing elements. In this case the flexible conductor is pressed against the movable electrical contact and the electrical terminal respectively with the at least one screwing element, e.g. screw or nut. Therefore, at least one through hole is provided at the ends of the flexible conductor for respective screwing elements. Flexible conductors are usually used for lower nominal currents and by treated parts; multi-contacts are usually used for higher nominal currents.

    [0008] The needed thickness of the flexible conductor grows by increasing the nominal current. In consequence, for high nominal currents a flexible conductor cannot be used, since the diameter of the movable electrical contact is usually too small for attaching the flexible conductor to the outer surface of the movable electrical contact which is arranged outside the interrupter.

    [0009] US 2009/218319 A1 discloses a connection with a flexible conductor at the moving contact side, wherein the flexible conductor as well as two adjacently arranged gripping faces are provided with inside threads, secured by one common screw bolt. This is an connection is ineffective in sense of good mechanical and electrical fixation.

    Summary of the invention



    [0010] It is an object of the present invention to provide a safe and movable electrical connection between the movable electrical contact of a circuit-breaker interrupter and its connection support of the insulating housing or which is suitable for high nominal currents.

    [0011] According to the invention the critical second end of the flexible conductor which is used for attaching the electrical conductor to the movable low electrical contact is provided with an inside thread which is screwed on an outside thread arranged on the distal end section of the movable lower electrical contact.

    [0012] Due to the special mechanical connection of the flexible conductor on the electrical contact side, it can be used for a high nominal currents in the same way as treated parts like tubes, etc. Therefore, the flexible conductor should be relatively thick on the end side which is provided with the inside thread according to the invention.

    [0013] Preferably, an inside thread is provided at the front side of the distal end of the movable lower electrical contact in order to connect a pushrod which is a part of a jackshaft arrangement operated by an actuator for axially moving the lower electrical contact of the vacuum interrupter. By means of the inside thread on the lower electrical contact the pushrod is mountable in an easy manner and it is possible to adjust the operating hub of the movable lower electrical contact by screwing in or out the pushrod in relation to the movable lower electrical contact.

    [0014] According to another aspect of the invention a screw-nut for securing the flexible conductor to the movable electrical contact is additionally screwed on the outside thread of the movable electrical contact. Instead of a screw-nut it is also possible to use a washer for securing the flexible conductor on the movable electrical contact. In case of a washer it is arranged between the distal end of the movable lower electrical contact and the push rod put-on the outside thread of the push rod for screwing the pushrod into the inside thread of the movable lower electrical contact. Of course, the inside thread can also be arranged on the side of the pushrod.

    [0015] According to a preferred embodiment the pushrod is axially attached to the movable lower electrical contact via a threaded stud section of the pushrod which is screwed into the inside thread of the movable lower electrical contact.

    [0016] According to another aspect of the present invention the first end of the flexible conductor which corresponds to a support plate in the insulating housing is provided with at least one through hole. Corresponding screws are used for connecting the first end of the flexible conductor to fasting element via the said through holes.

    [0017] Preferably, the flexible electrical conductor consists of copper material in the form of a non-woven fabric, especially a fleece or a fiber material.

    Brief description of the drawings



    [0018] The foregoing and other aspects of the invention will become apparent following the detailed description of the invention, when considered in conjunction with the enclosed drawings.

    Figure 1 is a sight view of a medium-voltage circuit-breaker arrangement operated by a single magnetic actuator via a jackshaft arrangement,

    Figure 2 a side view of a medium voltage switchgear

    Figure 3 is a detailed view of an electrical junction between the flexible conductor and the movable lower electrical contact of the interrupter, and

    Figure 4 is a perspective view of the pole part of the medium-voltage circuit-breaker according to Figure 1 in the section of the lower electrical terminal.



    [0019] All drawings are schematic.

    Detailed description of the drawings



    [0020] The medium-voltage circuit-breaker as shown in figure 1 shows an insulating housing 1 for the use of an assembled pole, with an upper electrical terminal 2 and at the lower point a support or support plate for the electrical connection.

    [0021] The invention can therefore be used for both applications, in assembled pole parts and in embedded pole parts as well.

    [0022] The medium-voltage circuit-breaker as shown in figure 2 principally consists of an insulating housing 1 with an embedded upper electrical terminal 2 and a lower electrical terminal 3 forming an electrical switch for medium-voltage circuit.

    [0023] Therefore, the upper electrical terminal 2 is connected to a corresponding fixed upper electrical contact 7 which is stationary mounted in a vacuum interrupter insert 8. The corresponding lower electrical contact 4 is movable mounted in relation to the vacuum interrupter insert 8.

    [0024] The lower electrical terminal 3 is connected to a corresponding lower electrical contact 4, which is axially movable arranged in relation to the insulation housing 1. The lower electrical contact 4 is movable between a closed and opened switching position via a jackshaft arrangement 5.

    [0025] A flexible conductor 6 of copper material is provided in order to electrically connect the lower electrical terminal 3 with the lower electrical contact 4. The jackshaft arrangement 5 internally couples the mechanical energy of a bistable magnet actuator 9 to the insulating housing 1 of the vacuum interrupter insert 8. The magnetic actuator 9 consists of a bistable magnetic arrangement for switching of an armature 10 to the relative position as effected by magnetic fields generated by an - not shown - electrical magnet as well as a permanent magnet arrangement.

    [0026] The insulation housing 1 supports and houses the vacuum interrupter insert 8 comprising the two corresponding electrical switching contacts 4 and 7 which are switchable under vacuum atmosphere. The said electrical switching contacts 4 and 7 of the vacuum interrupter insert 8 are electrically connected to the upper electrical terminal 2 and the lower electrical terminal 3 respectively as described above. On the side of the lower electrical terminal 3 a first end 11 of the flexible conductor 6 is attached to the lower electrical terminal 3 by at least one corresponding screw 12.

    [0027] According to Figure 3 the second end 13 of the flexible conductor 6 comprises an inside thread 14 which is screwed on an outside thread 15 arranged on the distal end of the movable lower electrical contact 4. An inside thread 16 is provided on the front side on the distal end of the movable lower electrical contact 4. A pushrod 17 which is a part of the - not shown - jackshaft arrangement is screwed in the inside thread 16 of the movable lower electrical contact 4 in order to provide a mechanical connection of both parts for axially moving the movable lower electrical contact 4.

    [0028] For securing the flexible conductor 6 on the movable electrical contact 4 a washer 18 is arranged between the distal end of the movable electrical contact 4 and the pushrod 17. The said washer 18 is screwed on a threaded stud section 19 of the pushrod 17. Thus, the pushrod 17 is axially attached to the movable lower electrical contact 4 via a threaded stud section 19 which is screwed in the inside thread 16 of the movable lower electrical contact 4.

    [0029] According to Figure 4 at the first end 11 of the flexible conductor at least one through hole 20 is provided for connecting the said first end 11 of the flexible conductor 6 by corresponding screws 12 (schematically) to the - not shown - lower electrical terminal 3.

    [0030] The invention is not limited by the preferred embodiment as described above which is presented as an example only but can be modified in various ways within the scope of protection defined by the patent claims. Especially, instead of a washer 18 a screw-nut can also be used for securing the flexible conductor 6 on the movable lower electrical contact 4.

    Reference signs



    [0031] 
    1
    insulating housing
    2
    upper electrical terminal
    3
    support plate
    4
    lower electrical contact
    5
    jackshaft arrangement
    6
    flexible conductor
    7
    upper electrical contact
    8
    vacuum interrupter insert
    9
    magnetic actuator
    10
    armature
    11
    first end
    12
    screw
    13
    second end
    14
    inside thread
    15
    outside thread
    16
    inside thread
    17
    pushrod
    18
    washer
    19
    threaded stud section
    20
    through hole



    Claims

    1. A pole part of a circuit-breaker arrangement comprising an insulation housing (1) for accommodating a vacuum interrupter (8) containing a pair of corresponding electrical switching contacts (4, 7), wherein a fixed upper electrical contact (7) is connected to an upper electrical terminal (2) molded or assembled in the insulation housing (1) and a movable lower electrical contact (4) is connected to a electrical contact element (3) of the insulation housing (1) via a flexible conductor (6) comprising a first end (11) for attaching the flexible conductor (6) to the insulation housing (1) and a second end (13) for attaching the flexible conductor (6) to the movable lower electrical contact (4), wherein the second end (13) of the flexible conductor (6) is provided with an inside thread (14) which is screwed to an outside thread (15) arranged on the distal end of the movable lower electrical contact (4),
    characterized in that a screw-nut for securing the flexible conductor (6) on the movable lower electrical contact (4) is additionally screwed on the outside thread (15) of the movable lower electrical contact (4).
     
    2. A pole part according to Claim 1,
    characterized in that the front side on the distal end of the movable lower electrical contact (4) is provided with an inside thread (16) for axially connecting a pushrod (17) to the movable lower electrical contact (4) of the vacuum interrupter insert (8).
     
    3. A pole part according to Claim 1,
    characterized in that a washer (18) for securing the flexible conductor (6) on the movable lower electrical contact (4) is arranged between the distal end of the movable lower electrical contact (4) and the pushrod (17).
     
    4. A pole part according to Claim 3,
    characterized in that the washer (18) is screwed on a threaded stud section (19) of the pushrod (17).
     
    5. A pole part according to Claim 4,
    characterized in that the pushrod (17) is axially attached to the movable lower electrical contact (4) via the threaded stud section (19) which is screwed in the inside thread (16) of the movable lower electrical contact (4).
     
    6. A pole part according to Claim 1,
    characterized in that the first end (11) of the flexible conductor (6) is provided with at least one through hole (20) for connecting the first end (11) of the flexible conductor (6) by corresponding screws (12) to insulation housing by a support plate.
     
    7. A pole part according to at least one of the preceding Claims,
    characterized in that the flexible electrical conductor (6) consists of copper material in the form of a fleece or a fiber.
     


    Ansprüche

    1. Polteil einer Schutzschalteranordnung mit einem Isoliergehäuse (1) zur Aufnahme eines Vakuumunterbrechers (8), der ein Paar entsprechender elektrischer Schaltkontakte (4, 7) enthält, wobei ein fester oberer elektrischer Kontakt (7) mit einem im Isoliergehäuse (1) geformten oder montierten oberen elektrischen Anschluss (2) verbunden ist und ein beweglicher unterer elektrischer Kontakt (4) über einen flexiblen Leiter (6), der ein erstes Ende (11) zur Befestigung des flexiblen Leiters (6) an dem Isoliergehäuse (1) und ein zweites Ende (13) zur Befestigung des flexiblen Leiters (6) an dem beweglichen unteren elektrischen Kontakt (4) umfasst, mit einem elektrischen Kontaktelement (3) des Isoliergehäuses (1) verbunden ist,
    wobei das zweite Ende (13) des flexiblen Leiters (6) mit einem Innengewinde (14) versehen ist, das mit einem am distalen Ende des beweglichen unteren elektrischen Kontakts (4) angeordneten Außengewinde (15) verschraubt ist,
    dadurch gekennzeichnet, dass eine Schraubenmutter zur Sicherung des flexiblen Leiters (6) an dem beweglichen unteren elektrischen Kontakt (4) zusätzlich auf das Außengewinde (15) des beweglichen unteren elektrischen Kontakts (4) geschraubt ist.
     
    2. Polteil nach Anspruch 1,
    dadurch gekennzeichnet, dass die Vorderseite am distalen Ende des beweglichen unteren elektrischen Kontakts (4) mit einem Innengewinde (16) zum axialen Verbinden eines Stößels (17) mit dem beweglichen unteren elektrischen Kontakt (4) des Vakuumunterbrechereinsatzes (8) versehen ist.
     
    3. Polteil nach Anspruch 1,
    dadurch gekennzeichnet, dass eine Unterlegscheibe (18) zum Sichern des flexiblen Leiters (6) an dem beweglichen unteren elektrischen Kontakt (4) zwischen dem distalen Ende des beweglichen unteren elektrischen Kontakts (4) und dem Stößel (17) angeordnet ist.
     
    4. Polteil nach Anspruch 3,
    dadurch gekennzeichnet, dass die Unterlegscheibe (18) auf einen Gewindezapfenabschnitt (19) des Stößels (17) geschraubt ist.
     
    5. Polteil nach Anspruch 4,
    dadurch gekennzeichnet, dass der Stößel (17) über den Gewindezapfenabschnitt (19), der in das Innengewinde (16) des beweglichen unteren elektrischen Kontakts (4) geschraubt ist, axial an dem beweglichen unteren elektrischen Kontakt (4) befestigt ist.
     
    6. Polteil nach Anspruch 1,
    dadurch gekennzeichnet, dass das erste Ende (11) des flexiblen Leiters (6) mit mindestens einem Durchgangsloch (20) zur Verbindung des ersten Endes (11) des flexiblen Leiters (6) durch entsprechende Schrauben (12) über eine Stützplatte mit dem Isoliergehäuse versehen ist.
     
    7. Polteil nach mindestens einem der vorhergehenden Ansprüche,
    dadurch gekennzeichnet, dass der flexible elektrische Leiter (6) aus Kupfermaterial in Form eines Vlieses oder einer Faser besteht.
     


    Revendications

    1. Partie polaire d'un agencement de disjoncteur comprenant un logement isolant (1) pour abriter un interrupteur à vide (8) contenant une paire de contacts de commutation électriques correspondants (4, 7), un contact électrique supérieur fixe (7) étant connecté à une borne électrique supérieure (2) laquelle est moulée ou assemblée dans le logement isolant (1), et un contact électrique inférieur mobile (4) étant connecté à un élément de contact électrique (3) du logement isolant (1) par l'intermédiaire d'un conducteur flexible (6) comportant une première extrémité (11) destinée à attacher le conducteur flexible (6) au logement isolant (1) et une deuxième extrémité (13) destinée à attacher le conducteur flexible (6) au contact électrique inférieur mobile (4),
    la deuxième extrémité (13) du conducteur flexible (6) étant dotée d'un filetage interne (14) qui est vissé sur un filetage externe (15) agencé sur l'extrémité distale du contact électrique inférieur mobile (4),
    caractérisée en ce qu'un écrou à vis, destiné à assujettir le conducteur flexible (6) sur le contact électrique inférieur mobile (4), est vissé en outre sur le filetage externe (15) du contact électrique inférieur mobile (4).
     
    2. Partie polaire selon la revendication 1,
    caractérisée en ce que le côté frontal sur l'extrémité distale du contact électrique inférieur mobile (4) est doté d'un filetage interne (16) pour raccorder axialement un poussoir (17) au contact électrique inférieur mobile (4) de la pièce rapportée de l'interrupteur à vide (8).
     
    3. Partie polaire selon la revendication 1,
    caractérisée en ce qu'une rondelle (18), destinée à assujettir le conducteur flexible (6) sur le contact électrique inférieur mobile (4), est agencée entre l'extrémité distale du contact électrique inférieur mobile (4) et le poussoir (17).
     
    4. Partie polaire selon la revendication 3,
    caractérisée en ce que la rondelle (18) est vissée sur une section à ergot fileté (19) du poussoir (17).
     
    5. Partie polaire selon la revendication 4,
    caractérisée en ce que le poussoir (17) est attaché axialement au contact électrique inférieur mobile (4) par l'intermédiaire de la section à ergot fileté (19) qui est vissée dans le filetage interne (16) du contact électrique inférieur mobile (4).
     
    6. Partie polaire selon la revendication 1,
    caractérisée en ce que la première extrémité (11) du conducteur flexible (6) est dotée d'au moins un trou traversant (20) pour permettre de raccorder, au moyen de vis correspondantes (12), la première extrémité (11) du conducteur flexible (6) au logement isolant grâce à une plaque de support.
     
    7. Partie polaire selon au moins une quelconque des revendications précédentes,
    caractérisée en ce que le conducteur électrique flexible (6) consiste en un matériau en cuivre sous la forme de bourre ou de fibres.
     




    Drawing














    Cited references

    REFERENCES CITED IN THE DESCRIPTION



    This list of references cited by the applicant is for the reader's convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.

    Patent documents cited in the description