EP1488438B1 - Circuit breaker having double pole interruption - Google Patents

Abstract

The invention relates to a circuit breaker having double pole interruption, comprising a first and second contact device, each of which having a stationary contact (26) and a moving contact (23), whereby both moving contacts (23) are mounted on a supporting body (11) in a manner that enables them to pivot about a common pivot axis (24) while each being pretensioned in their closed position by a contact spring (28). The circuit breaker also comprises a switching lever (21), which is pivotally mounted on the supporting body (11) and is pretensioned by the contact springs (28) of the moving contacts (23) in an interrupt position, in which the switching lever (21) holds the moving contacts (23) in their breaking position. The circuit breaker additionally has a switch actuating element (31) that can be coupled to the switching lever (21) via a coupling device (32, 20), whereby the switch actuating element (31) enables the switching lever (21) to pivot out of its interrupt position and into an enable position against the force of the contact springs (28) and to be held in this enable position as long as the switch actuating element (31) is coupled to the switching lever (21). The coupling device has a coupling element (32), which is coupled to the switch actuating element, and a detent (20), which is pivotally mounted on the switching lever (21) and holds the coupling element (32) in contact therewith or releases it depending on the position relative to the switching lever. Finally, the circuit breaker comprises a trip element (16), which acts upon the detent (20) in the event of a fault whereby causing the detent to release the coupling element (32).

Description

The invention relates to a circuit breaker with two-pole interruption to protect lines against fault currents, especially against thermal overload and short circuit.

So far, at least in Central Europe usually circuit breaker for alternating current in use, which interrupt the circuit unipolar. Since such circuit breakers are commonly used in so-called zeroed networks, ie in network systems in which the neutral conductor is grounded on the part of the power company, a break in the neutral conductor in the house installation in case of failure is not required.

In the course of globalization, however, it is becoming increasingly difficult to ensure that these neutralization conditions, ie the power supply neutral grounding of the neutral conductor throughout Europe, so that already in some European countries, the two-pole shutdown of the circuits to be protected for safety is required.

From DE 39 15 127 C1 a circuit breaker with unipolar interruption is known, which has a contact device with a fixed contact and a movable contact, which is biased by a contact spring in its closed position. For switching on and off of the switch, a manual switch is provided, which is connected via a coupling device with a shift lever, which is biased by a switching spring in its position separating the two contacts. A pawl, which is pivotable about the same axis as the shift lever, serves to operatively hold the coupler in engagement with the shift lever so that the switch can be manually opened and closed. An overcurrent release cooperates with the pawl to operate in case of failure, the pawl so that the shift lever is released to be pivoted by the switch spring in its contact interrupting position. In this case, the shift lever must move the movable contact against the force of the contact spring in its interruption position.

If such a circuit breaker are triggered so that it interrupts both poles of a line, it is not easy to double the elements of the known circuit breaker, since the functional elements of the two-pole circuit breaker should be housed in the volume of a previous single-pole circuit breaker, so no additional Changes to the respective control cabinets or systems are required. The main problem is the overcurrent release, which takes up the most space and therefore can not be doubled. Thus, the difficulty is that this overcurrent release, although the triggering forces for the unlatching of a single-pole circuit breaker applies, the double forces, as required for a two-pole switch, but not mastered.

Overcurrent release, which cause both in the case of short circuit as well as thermal overloading an interruption of the line, so opening the contacts are known for example from DE 199 42 694 A1 and EP 0 917 173 A2.

Document EP 0 691 665 A (see in particular Fig. 7) discloses a circuit breaker according to the preamble of claim 1.

The object of the present invention is to design a circuit breaker with a two-pole break so that the tripping forces for two contacts to be interrupted can be applied by a single trigger, so that all functional elements of the circuit breaker can be accommodated in the construction volume of a conventional single-pole circuit breaker.

This object is achieved by the circuit breaker according to claim 1. Advantageous developments and refinements of the invention are described in the subclaims.

Thus, according to the invention, a circuit breaker with a two-pole interruption comprises a first and a second contact device, each of which comprises a fixed contact and a movable contact, wherein the two movable contacts are pivotally mounted about a common pivot axis on a support body and each biased by a contact spring in its closed position are, a shift lever mounted pivotally on the support body, which is spring-biased by the contact springs of the movable contacts in a breaker position, in which he the movable contacts holds in its off position, a switch operating member which is coupled via a coupling device with the shift lever, so that the shift lever is pivotable by means of the switch actuator from its breaker position against the force of the contact springs in a release position and can be held in this, as long as the switch actuator with the Gear lever is coupled, wherein the coupling device comprises a hinged to the switch actuating element coupling element and a pivotally mounted on the shift lever pawl which holds the coupling element depending on the position relative to the shift lever in engagement with this or releases, and a trigger which acts in the event of a fault on the pawl in that it releases the coupling element.

According to the invention, a single spring per contact point is thus used at the same time as a switching spring, so that the demands for sufficient contact force, tearing force and Entklinkungskraft be achieved for a two-pole switching device skillfully.

According to an advantageous embodiment of the invention it is provided that the contact springs are each supported at one end to the movable contact and with its other end to the shift lever.

In order to achieve a particularly suitable adaptation of the individual components to the required construction volume, it is provided that the shift lever is formed symmetrically to a plane perpendicular to its pivot axis, and that the movable contacts arranged symmetrically with respect to this plane in the region of the axial outer surfaces of the shift lever are, wherein the shift lever in the region of its plane of symmetry has a parallel incision, in which the pawl is pivotally mounted.

A particularly expedient development of the invention is characterized in that the switching lever, which is substantially circular in section about its pivot bearing, has a recess extending essentially arcuately around its pivot bearing, and in that the pivot axis of the movable contacts is arranged at such a distance from the pivot bearing of the control lever is that it lies within the outer contour of the shift lever in the arcuate recess, wherein in Outer peripheral portion of the lever for each movable contact a driver element is provided to take the movable contacts in case of failure in their off position.

It is particularly expedient if the contact springs are each supported at one end in the region of the outer circumference of the shift lever and with its other end to the movable contact, that the contact springs with their movable contacts facing end portions between each of the driver elements and the Swivel axis of the movable contacts are.

This ensures that, in the event that the movable contact is in contact with the fixed contact, while the shift lever is fixed in its release position, the force of the contact spring causes the closing force, while the entire force is also available as a tearing force.

In order to obtain an indication of an opened due to a fault current circuit breaker is provided in another advantageous embodiment of the invention that on the shift lever a driver spring is provided for the switch actuator to bring the switch actuator after a trip in case of failure in the middle position, wherein the driver spring is made in one piece with a contact spring.

In order to obtain a particularly good utilization of the module width of 18 mm today, is provided in a particularly preferred embodiment of the invention that the trigger, the contact devices with associated extinguishing chambers, and the shift lever with the associated pawl on the common, T-shaped support body symmetrical arranged to it.

As a result, not only the entire mechanics and electrical system of the circuit breaker in the conventional module width can be realized, but it is also possible that the complete system in the open state, ie without the aid of housing covers is possible.

Furthermore, by using the common support body as a basis for all functional parts both a largely tolerance independent functioning As well as a favorable condition for fully automatic production in mass production guaranteed.

• Figur 1 eine vereinfachte schematische Seitenansicht eines Leitungsschutzschalters nach der Erfindung, wobei eine seitliche Abdeckung teilweise weggebrochen ist, um die Funktionselemente im Innern zu zeigen,
• Figur 2 eine Draufsicht von unten auf den erfindungsgemäßen Leitungsschutzschalter nach Figur 1,
• Figuren 3a bis 3c eine Seitenansicht des Schalt- und Auslösemechanismuses in verschiedenen Funktionsstellungen und
• Figuren 4a bis 4c teilweise geschnittene Seitenansichten, entsprechend den Figuren 3a bis 3c zur Veranschaulichung der Schalterfunktion.

The invention will be explained in more detail below, for example, with reference to the drawing. Show it:

• 1 is a simplified schematic side view of a circuit breaker according to the invention, wherein a side cover is partially broken away to show the functional elements in the interior,
• FIG. 2 shows a top view from below of the circuit breaker according to the invention according to FIG. 1,
• Figures 3a to 3c is a side view of the switching and triggering mechanism in different functional positions and
• Figures 4a to 4c partially sectioned side views, corresponding to Figures 3a to 3c to illustrate the switch function.

In the various figures of the drawing corresponding components are provided with the same reference numerals.

As can be seen in Figures 1 and 2, a support body 10 is closed with the functional parts thereon by a left and right cup-shaped cover 11, 12. In this case, the support body 10 and the two covers 11, 12 are connected together in a manner not shown by means of molded rivet pins. After the installation of the circuit breaker according to the invention in a distribution box or a control cabinet then the visible part of the housing is formed essentially only by the two covers 11, 12.

The circuit breaker according to the invention is equipped with two input-side terminals 13 and two output-side terminals 14 (only one of which is shown), which can be configured either as a screw or plug-in terminals. In particular, with plug-in terminals, it is advantageous if the connection as in the output-side terminal 14 shown in Figure 1 from the front, ie in the field of view of Montierenden after attaching the circuit breaker can be done on a mounting rail, not shown in the distribution box or cabinet. For this purpose, these terminals 14 designed as plug-in terminals are reset, so that there is sufficient space for the connection between a cover plate, not shown, of the distributor box and the connection terminal 14.

In a recess 15 of the support body 10, a trigger 16 is arranged substantially symmetrically to this, which is preferably designed for thermal and magnetic tripping in case of failure. For this purpose, the trigger 16 has a bimetallic disc 17 for thermal tripping and a coil 18 for magnetic tripping. A trigger handle 19 acts, as can be seen particularly clearly in Figures 4a to 4c, with a pawl 20 which is pivotally mounted on a shift lever 21.

The shift lever 21, which can be seen particularly well in FIGS. 3 a to 4 c, has an essentially circular-shaped outer contour, is pivotably mounted on a bearing journal 10 provided on the support body 10 and is designed symmetrically to a plane extending perpendicular to its pivot axis. The swivel lever therefore has the same elements on its side, which in FIG. 1 shows the rear side, as on its front side shown in FIG. In addition, it can be seen in Figures 4a to 4c, which show the shift lever 21 cut, that it has a substantially lying in the plane of symmetry incision, in which the pawl 20 is pivotally supported, and in which the trigger key 19 of the trigger 16 for actuating the pawl 20 can engage.

On both sides of the shift lever 21, a movable contact 23 on the support body 10 is pivotally mounted on a pivot pin 24. The shift lever 21 has an arcuate recess 21 ', which is arranged so that the or the pivot pin 24 in this recess 21' is or lie so that a pivoting movement of the shift lever is not hindered.

The movable contacts 23 are connected via leads 25 to the respective terminal 13. In its closed position, the movable contact 23 bears against a fixed contact 26, of which the one is connected via the coil 18 with its connection terminal 14. The other hard contact, which is arranged on the side to be viewed in the back side in FIG. 1 of the support body 10, is connected directly to the associated connection terminal 14.

The contact devices of movable contact 23 and fixed contact 26 are each associated with extinguishing chambers 27, of which in turn only the one on the left or right side of the support body 10 is shown arranged.

The person skilled in the art recognizes that the functional elements described with reference to FIG. 1 are provided in a mirror-image form on the other, the right-hand or rear side of the support body 10 in a corresponding manner. In the following, therefore, only the function and structure of the elements shown in the drawing will be explained.

A contact spring 28, which also serves as Aufreißfeder, is supported at one end to a provided on the outer circumference of the shift lever 21 pin 29 and with its other end on the movable contact 23. In order to demolish the movable contact 23 from the fixed contact 26 in a still to be described movement of the shift lever 21 from its release position shown in Figure 1 in an interrupting position, a curved stop web 30 is provided as a driver. However, the driver element may also have any other suitable shape, which allows a reliable power transmission from the shift lever 21 to the movable contact 23.

In order to be able to move the shift lever from its interruption position into its release position and back by means of a switching handle 31 serving as a switch actuating element, a coupling element 32 is pivotally connected to the control handle 31, which is held in coupling engagement with the shift lever 21 by means of the pawl 20.

In order to move the movable contact from the breaker position shown in Figures 3a and 4a in its closed position, the switching handle 31 is moved in Figures 3a and 4a in the counterclockwise direction, so that it via the coupling member 32 that of the pawl 20 in coupling engagement with the Shift lever 21 is held, the shift lever 21 is moved clockwise. Due to the contact spring 28, the movable contact 23 is taken as long until it rests against the fixed contact 26. Upon further movement of the shift lever 21 in its locked release position, which is shown in Figure 3b and 4b, the stop web 30 releases from the movable contact 23, so that the contact spring 28, which is supported at one end to the movable contact 23, with her the other end via the shift lever 21, the coupling element 32 and the handle 31 is supported on the support body, the full closing force provides.

In the on state, the current flow from the terminal 13 via the flexible wire 23 to the contact device made of movable contact 23 and fixed contact 26 and further via the coil 18 of the trigger 16 to terminal 7. In the event of a fault, either the bimetallic disc 18 located in the trigger 16 or the magnet armature respond and move the trigger plunger 19 in Figure 1 down or in Figures 3a to 4c to the right. Thereby, the pawl 20 is rotated counterclockwise about its pivot point 20 ', whereby the coupling element 32 is released. Thus, the locking of the shift lever 21 is released in its release position, so that the contact spring 28 now serves as Aufreißfeder which is supported on the movable contact 23 its bearing pin 24 and the fixed contact 26 as long as the support body 10 to deliver the tearing force until the stop web 30 strikes against the movable contact 23 and this breaks off from the fixed contact 26. Thus, the shift lever 21 and thus the movable contact 23 is moved by acting as a tear-off spring contact spring 28 in the position shown in Figure 3c and 4c until the shift lever 21 and the pawl 20 to stops 10a and 10b on the support body 10 (in the Figures 3a to 4c not shown) is applied.

A follower spring 33, which is mounted on the pin 29 on the shift lever 21 and cooperates with a projection 34 on the handle 31, rotates the handle 31 in an intermediate position, which indicates that the circuit breaker has interrupted the lines due to a fault.

In the event of a short circuit, that is to say at higher exciter currents, the triggering plunger 19 of the trigger 16 is driven so strongly by the magnet armature that not only the unlatching, as described above, is completed, but that via a connecting web 35, against which the latch 21 from the triggering plunger 19 is pressed, the ram force is transmitted to the shift lever 21 and thus to the movable contact 23. As a result, an additional acceleration of the movable contacts 23 occurs in the event of a short circuit.

For reconnection, the control handle 31 must first be rotated clockwise to pull the coupling member 32 between the pawl 20 and the shift lever 21 until it locks with the pawl 20, as shown in Figure 3a and 4a. Subsequently, the renewed activation takes place as already explained above.

By using commercially available components, such as the trigger and the quenching chamber, resulting from their arrangement on the common support body 10 in conjunction with the lever with pawl and the terminals a transportable unit for mass production. After only different magnetic coils are required for the different nominal currents of the circuit breaker, but the remaining component remain the same, there are considerable advantages for warehousing and production.

The combination of the trigger 16 in conjunction with the lever equipped with a pawl and other functional parts provides a largely tolerance-independent arrangement which does not require any adjustments for operation.

Due to the same dimensions of the two-pole circuit breaker over the unipolar devices, it is easily possible to replace in existing switch or distribution boxes in system changes unipolar machine through the two-pole circuit breaker according to the invention, without the other changes to the switch or junction boxes would be required.

A second embodiment of the present invention will be explained in more detail below with reference to FIGS. 5a, 5b, 6a, 6b and 7a, 7b. In this case, components which are identical to those of the first embodiment are not described again.

In order to move in the circuit breaker according to the second embodiment of the invention, the movable contacts 23 in their interruption position (see Figures 6b and 7b), instead of or in addition to the stop web 30, a hammer 40 is provided which, like Figures 5a and 5b show two Strikes 42 and two guide cheeks 43 having a receiving space formed therebetween 44 for a support body 10 formed on the guide wall. The guide cheeks 43 at its one end bearing central portion 45 of the hammer 40 has at its other end an extension or nose 46 which forms a shoulder or step 47 with the central portion 46. The nose 46 of the hammer 40 is performed as the pawl 20 in the recess in the shift lever 21.

As can be seen in FIGS. 6 a and 7 a, the striking lever 40 is mounted between the shift lever 21, the supporting body 10 and the movable contacts 23 in such a way that it partially surrounds the middle pin 45 and the extended nose 46 about the bearing pin 24 of the movable contacts 23 herumerstreckt while the flaps 42 on a projection 23 'of the movable contacts 23 in abutment.

If the trigger push rod 19 of the trigger 16 is displaced from the position shown in FIGS. 6 a and 7 a to the right into the position shown in FIG. 7 b, then first the pawl 20 is pivoted, as described in connection with the first exemplary embodiment, so that the coupling element 32 is released. At the same time the pawl 20 strikes against the hammer 40 and moves it so that the movement of the hammer 40, which is transferred by means of the strikes 42 on the movable contacts 23, this moves to its interruption position, as can be seen particularly well in Figure 7b. In order to ensure during the pivoting movement of the movable contacts 23 that the impact bars 42 of the hammer 40 remain in engagement with the stops 23 'of the movable contacts 23, a guide wall accommodated between the guide cheeks 43 of the hammer 40 can have a corresponding guide or cam surface.

After the opening movement of the movable contacts 23 of trip rod 19 and hammer 40 was initiated, and the shift lever 21 is moved to its interruption position, wherein he in the central region 45 of the hammer 40 laterally the pawl 20 impinges on this and after completion the tearing movement secures the movable contacts 23 via the hammer in its open position.

According to the second embodiment of the invention, therefore, an impact lever 40 is provided as an additional special element of the switching mechanism, via which the trigger plunger 19 of the trigger 16 acts on the movable contacts 23. In this way, a faster opening of the movable contacts can be achieved, so that a timely and reliable shutdown of the circuit breaker is ensured in the event of a short circuit or the like. In order to act on the two moving contacts uniformly, the hammer 40 is formed symmetrically to the center plane of the circuit breaker.

Claims (10)

1. Automatic circuit breaker comprising

   - a contact device which includes a fixed contact and a pivotable movable contact, said movable contact being biassed by a contact spring into its closed position,

   - a switch actuating element which acts on the movable contact (23) via a coupling element and a pivotable latch (20), and

   - a tripping device (16) which in case of a fault acts on the latch (20) in such a way that it releases the coupling element (32);

   characterized by

   - the first and a second contact device each of which comprises a fixed contact (26) and a movable contact (23), wherein the two movable contacts (23) are mounted on a supporting body (11) so as to be pivotable about a common pivot axis (24) and are biassed by a contact spring (28) into their respective closed position,

   - a switching lever (21) which is mounted pivotably on the supporting body (11) and biassed by the contact springs (28) of the movable contacts (23) into an interrupt position in which it keeps the movable contacts in their switched-off position,

   - a switch actuating element (31) which can be coupled by a coupling device (32, 20) to the switching lever (21) so that the switching lever (21) is pivotable by means of the switch actuating element (31) out of its interrupt position against the force of the contact springs (28) into a release position and can be held fast in this position as long as the switch actuating element (31) is coupled to the switching lever (21),

   - wherein the coupling device includes the coupling element (32) linked to the switch actuating element and the latch (20) mounted pivotably on the switching lever (21), said latch (20) keeping the coupling element (32) engaged with the switching lever (21) or releasing it, depending on the position relative to the switching lever.
2. Automatic circuit breaker according to claim 1, characterised in that the contact springs (28) are each supported by one end on the movable contact (23) and by the other end on the switching lever (21).
3. Automatic circuit breaker according to claim 1 or 2, characterised in that the switching lever (21) is designed symmetrically to a plane perpendicular to its pivot axis, and in that the movable contacts (23) in relation to this plane are arranged symmetrically to each other in the region of the axial outer surfaces of the switching lever (21).
4. Automatic circuit breaker according to claim 3, characterised in that the switching lever (21) in the region of its plane of symmetry has a notch parallel thereto, in which the latch (20) is mounted pivotably.
5. Automatic circuit breaker according to any of claims 1 to 4, characterised in that the switching lever (21), which is substantially sector-shaped about its pivot bearing (22), has a recess (21') partially extending substantially arcuately about its pivot bearing, and in that the pivot axis (22) of the movable contacts (23) is arranged at such a distance from the pivot bearing (22) of the switching lever (21) that it lies within the outer contour of the switching lever (21) in the arcuate recess (21').
6. Automatic circuit breaker according to claim 5, characterised in that in the outer circumferential region of the switching lever (21) for each movable contact is provided a driver element (30) for entraining the movable contacts (23) in case of a fault in their switched-off position.
7. Automatic circuit breaker according to claim 6, characterised in that the contact springs (28) are in each case supported by one end in the region of the outer circumference of the switching lever (21) and by the other end on the movable contact (23) in such a way that the contact springs (28) lie with their end regions facing towards the movable contacts in each case between one of the driver elements (30) and the pivot axis (24) of the movable contacts (23).
8. Automatic circuit breaker according to any of the preceding claims, characterised in that on the switching lever (21) is provided a driver spring (33) for the switch actuating element (31), for moving the switch actuating element (31) into a middle position after tripping in case of a fault.
9. Automatic circuit breaker according to claim 6, characterised in that the driver spring (33) is made in one piece with a contact spring (28).
10. Automatic circuit breaker according to any of the preceding claims, characterised in that the tripping device (16), the contact devices (23, 26) with associated explosion chambers (27) and the switching lever (21) with the associated latch (20) are arranged on the common, T-shaped supporting body (10) symmetrically thereto.

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