EP0569652A1 - Magnetic trip mechanism for circuit breaker, equivalent sub-assembly and circuit breakers incorporating them - Google Patents

Abstract

Magnetic trip mechanism for circuit breaker, in particular for phase/neutral circuit breaker, of the kind comprising on the one hand an induction coil (33) which is associated with a moving core with striker (90) and restoring spring inside an insulating sheath and which is mounted longitudinally in a yoke (34) having first and second flanks (80, 81) facing one another. The first flank (81) is fitted with a fixed core (85) within which the striker (90) is guided, the coil being provided with a first end (83) for connecting with the yoke and a second end (84) for connecting with a terminal (32) of the circuit breaker. The trip mechanism furthermore comprises a fixed contact (35) extending into an arc switching electrode (37). The yoke has a general U shape with a longitudinal arm (82) connecting the two facing flanks and is formed by stamping and bending a metal strip so as to incorporate the fixed contact and the switching electrode. <IMAGE>

Description

The present invention relates to a magnetic trip device for a circuit breaker, in particular for a phase and neutral circuit breaker, as well as to a magnetic sub-assembly incorporating it. It also relates to circuit breakers, in particular phase and neutral circuit breakers, in which such a trip device or such a sub-assembly is mounted.

Line protection circuit breakers generally include, in a modular box, a circuit extending between two terminals and comprising a thermal trip bimetal for protecting the line against overloads and, between a terminal and a fixed contact, a member electromagnetic tripping or magnetic trip device comprising a coil with a movable core associated with a striker to ensure, in the event of overcurrent, tripping by opening a movable contact cooperating with one or more fixed contacts. The phase and neutral circuit breakers further include a neutral stage with fixed and movable contacts, the movable neutral contact being actuated in conjunction with the movable phase contact.

Magnetic trip units generally include an induction coil which is associated with a movable core with striker and return spring and which is mounted longitudinally in a cylinder head having a first and a second facing flank, the first flank being provided with a fixed core in which the striker is guided. Until now, in the case of magnetic trip units electrically associating the fixed contact with the cylinder head, the induction coil was then connected by a first end to the cylinder head and had a second end connected to a terminal of the circuit breaker. Then reported on the cylinder head, for example by welding or by fixing using the fixed core, a piece of material good conductor of electricity, in particular copper, to form the fixed contact. In this type of configuration, the channeling to the arc breaking chambers of the electric arcs appearing during circuit breaks could be ensured in part by the part forming the fixed contact in connection with the cylinder head or by an appropriate extension of this part. forming a switching electrode.

These magnetic trip units are not only complex to make and assemble, but also difficult to arrange in the modular boxes intended to receive them, the installation precision, in particular of the fixed contact relative to the mobile contact, being a sine qua non condition their proper functioning.

The object of the invention is therefore to remedy these drawbacks by proposing magnetic triggers which are much easier to produce and which have greater precision in production both in the respective arrangement of the elements which compose them and in the relative position of these triggers. magnetic in the boxes, especially with regard to their fixing.

Another objective of the invention is to provide an inexpensive magnetic trigger, of small size and which consists of a reduced number of parts.

Another object of the invention is to provide a pre-assembled and rigid magnetic trip device which can be placed in one piece in a circuit breaker box.

The present invention therefore relates to a magnetic trip device of the type described at the start, characterized in that the cylinder head has a general U-shape with a longitudinal arm connecting the two sides opposite one another and in that it is formed by cutting and bending a metal strip so as to integrate the fixed contact and the switching electrode.

Preferably, the fixed contact comes in the extension of said first flank, that is to say from the edge of this flank opposite the edge connected to the longitudinal arm, and has a width less than that of this flank.

Very advantageously, in particular for phase and neutral circuit breakers, the fixed contact comes substantially in the extension of a part located in a transverse half of the first flank. Preferably then, the second end of the coil, that is to say the one which is intended to be connected to the connection terminal of the circuit breaker, is located on the same side as the fixed contact. In a phase and neutral circuit breaker, this advantageously makes it possible to arrange the yoke itself with the coil straddling the parts reserved for neutral and phase, while the fixed contact of the switching electrode penetrates only in the part reserved for the phase.

In addition, such a configuration, combined with the particular reliefs of the half-shell of the housing to which the trigger is attached, allows rapid and precise positioning. Said transverse half is therefore limited by a median plane substantially parallel to the plane of a half-shell.

Preferably, the induction coil has at least one straight end, that is to say that it has not been folded after winding, which on the one hand reduces the manufacturing costs, but above all avoids the usual folding operations which are difficult to achieve with precision. The realization with two straight ends is therefore preferred.

More preferably, the first end of the coil is straight and is welded to a tab forming an extension of the first side, this tab being oriented parallel to said straight end. This tab preferably comes from the cutting of the longitudinal arm of the cylinder head and it is located on the side opposite to the fixed contact.

According to a possible variant, the first end of the coil can be welded directly to the extension forming a fixed contact and switching electrode, as close as possible to the fixed contact, so as to limit the path of the coil current to the fixed contact.

Advantageously, the second end of the coil is welded to a conductive connecting piece which is both rigid and capable of coming into engagement rigidly with the connection terminal of the circuit breaker, so as to form an assembly which is also rigid. In order to ensure both mechanical connections that optimal electrical, the part of this connecting piece, intended to be welded to the second end of the coil, is inclined to take account of the orientation of this end.

For phase and neutral circuit breakers, the phase and neutral stages can be mounted on one side or the other of the housing to take account in particular of the standards in force in the different countries and it is therefore understood that it will be advantageous to produce two types of cylinder head, symmetrical to one another, with fixed contact and switching electrode to the right or to the left, a welding tab can be provided each time on the opposite side, which also requires a adaptation of the induction coil.

The invention also relates to magnetic sub-assemblies comprising, in the form of a pre-assembled and rigid entity, a magnetic trip device according to the invention with connection piece and connection terminal.

The invention finally relates to a circuit breaker comprising such a magnetic trip device or such a sub-assembly according to the invention.

The invention will now be described in more detail in the case of a phase and neutral circuit breaker taking advantage of the geometrical characteristics of the releases according to the invention and revealing their advantages. Figures 1 and 2 are views in longitudinal section of a phase and neutral circuit breaker according to the invention, with neutral on the left, Figure 1 showing the phase stage and Figure 2, the neutral stage.

Figure 3 is an exterior view of the circuit breaker according to Figures 1 and 2, showing a small side of said device.

Figures 4 and 5 are views in longitudinal section of a phase and neutral circuit breaker according to the invention with neutral on the right, Figure 4 showing the neutral stage and Figure 5, the phase stage.

FIG. 6 is a view similar to FIG. 3, for the circuit breaker of FIGS. 4 and 5.

Figure 7 is a side view of the magnetic sub-assembly according to the invention.

FIG. 8 is a sectional view along the section plane IX-IX of FIG. 7.

Figures 9 and 10 are perspective views of the magnetic sub-assembly, in the case of a left-side neutral circuit breaker.

Figures 11 and 12 show a variant of the magnetic sub-assembly, profit and perspective view respectively, also for the version with neutral on the left.

The circuit breakers according to the invention are preferably modular devices, that is to say those whose width is equal to a multiple of a defined module. They usually include a housing having a base 1 provided with means 2 for fixing and / or clipping (with optionally retractable latch, not shown) on a support rail (not shown), and a top 3 having an opening 4 for the passage of the handle or actuating lever 5a of an operating member 5 constituting one of the elements of a lock mechanism. The housing also usually has two short sides 6 and 7 having the electrical connection terminals and two large faces 8 and 9 called lateral faces, which are parallel to the median plane of the housing.

By convention, the left and right sides are defined with respect to the median plane of the device placed, by its base, against a vertical surface, with the actuation handle 5a in the "On" position upwards. By way of example, FIGS. 1 and 2 are partial left views of the interior of an apparatus according to the invention, and in FIG. 3, the right side of the sheet corresponds to the right side of the case, face 9.

We first refer to Figures 1 to 3 relating to a circuit breaker with neutral on the left.

In Figure 3, we see that the housing of this circuit breaker is formed of three parts, two left half-shells 10 and right 11 and an intermediate part forming a spacer 12 which will be described later.

The partial right views of Figures 1 and 2 show respectively the phase and neutral stages of the circuit breaker.

• un circuit de phase comportant d'une part une borne de raccordement 25 accessible par le petit côté 7 du boîtier, une tresse conductrice 26 reliée à une extrémité de la bilame thermique 27, dont l'autre extrémité est connecté à une seconde tresse conductrice souple 28 reliée au contact mobile 29, ce qui constitue le sous-ensemble thermique 30, et d'autre part, un sous-ensemble magnétique 31 (qui sera décrit en détail plus loin) comportant une borne de raccordement 32, accessible par le petit côté 6 du boîtier, et un moyen de disjonction électromagnétique à bobine de disjonction 33 et culasse 34, se prolongeant par un contact fixe 35;
• ce dernier ainsi que l'extrémité inférieure de la bilame 27 présentent chacun un prolongement formant des électrodes de commutation d'arc électrique, respectivement 37 et 36 ; et
• un sous-ensemble "déions" usuel 38 est placé entre ces deux électrodes 36 et 37.

The phase stage includes (Figure 1):

• a phase circuit comprising on the one hand a connection terminal 25 accessible from the short side 7 of the housing, a conductive braid 26 connected to one end of the thermal bimetal 27, the other end of which is connected to a second flexible conductive braid 28 connected to the movable contact 29, which constitutes the thermal sub-assembly 30, and on the other hand, a magnetic sub-assembly 31 (which will be described in detail below) comprising a connection terminal 32, accessible by the small side 6 of the housing, and an electromagnetic circuit breaker with circuit breaker 33 and cylinder head 34, extended by a fixed contact 35;
• the latter as well as the lower end of the bimetallic strip 27 each have an extension forming electric arc switching electrodes, respectively 37 and 36; and
• a usual "deion" sub-assembly 38 is placed between these two electrodes 36 and 37.

• un circuit de neutre comportant d'une part un sous-ensemble contact mobile de neutre, sous la référence 13, incluant successivement une borne de raccordement 14, dite à cage, accessible par le petit côté 7 du boîtier, une lame conductrice 15, une tresse conductrice souple 16 et un contact mobile 17, et d'autre part un sous-ensemble contact fixe, sous la référence 18, incluant une lame pliée 19 présentant une partie formant le contact fixe proprement dit 20 et une borne de raccordement 21 accessible par le petit côté 6 du boîtier ; dans chacun de ces sous-ensembles, comme dans ceux qui vont suivre, les éléments successifs sont reliés électriquement ;
• les lames 15 et 19 présentent chacune un prolongement formant électrode de commutation électrique d'arc, respectivement 22 et 23 ;
• un sous-ensemble "déions" usuel 24 formant chambre d'extinction d'arc, constituée d'un empilement de tôles, est placé entre les deux électrodes 22 et 23.

The neutral stage includes (Figure 2):

• a neutral circuit comprising on the one hand a movable neutral contact sub-assembly, under the reference 13, successively including a connection terminal 14, called a cage, accessible by the short side 7 of the housing, a conductive blade 15, a flexible conductive braid 16 and a movable contact 17, and on the other hand a fixed contact sub-assembly, under the reference 18, including a folded blade 19 having a part forming the fixed contact proper 20 and a connection terminal 21 accessible by the small side 6 of the housing; in each of these subsets, as in those which will follow, the successive elements are electrically connected;
• the blades 15 and 19 each have an extension forming an electric arc switching electrode, respectively 22 and 23;
• a conventional "deion" sub-assembly 24 forming an arc extinguishing chamber, consisting of a stack of sheets, is placed between the two electrodes 22 and 23.

We see that the phase and neutral terminals are, as is customary, respectively shifted in height, for polarization purposes.

The circuit breaker further comprises the above-mentioned operating member 5 with its actuating lever 5a, intended to act, by means of a link 39, on the lock mechanism 40 which mainly comprises a movable contact carrier 41 with a toggle joint device, cooperating with the link 39 and with a pawl 42 secured to a triggering part 43, which is biased by the coil 33 and by the bimetallic strip 27, in the latter case via a driver 44.

In the case of a circuit breaker with neutral and to the right, the general arrangement of the phase and neutral stages is the same as above, if not their place on either side of the median plane of the housing, as can be seen in FIGS. 4 and 5. In particular, the identical orientation of the different constituent elements in the plane of the housing will be noted, compared to the previous embodiment. As a result, the left and right half-shells and the spacer are specific to the chosen configuration, neutral on the left or neutral on the right. For the present case, a right half-shell 10 'is used for the neutral side, a spacer 12' and a left half-shell 11 '.

Reference is now made to FIGS. 7 to 11 for the description of the preferred magnetic sub-assembly 31, designed so as to form a rigid assembly.

The magnetic sub-assembly 31 comprises the yoke 34 obtained from a single piece cut and folded to present two sides 80 and 81 parallel to each other and joined together by a longitudinal arm 82, inside a transverse half of the flank 81 extending to form the fixed contact 35 (with silver contact pad, welded), then, by a parallel part and opposite said arm 82, the switching electrode 37.

The magnetic part consists of the coil 33 obtained by simple winding, without subsequent folding of the protruding ends 83 and 84, a fixed core 85 engaged in an orifice 86 formed in the sidewall 81, an insulating sheath 87 extending from the fixed core projecting through an orifice 88, formed in the sidewall 80 and aligned with the previous one, as well as a core 89 movable in said insulating sheath 87, separated from the fixed core 85 by a compression spring (not shown) and intended for drive the striker 90 guided in said fixed core 85.

The fixed core 85, the insulating sheath 87, the movable core 89, the striker 90 and the spring form a pre-assembled sub-assembly, slid from the rear 80 and clipped at this location.

The coil type spring varies according to the curves associated with the different types of circuit breakers: when it comes to delaying the magnetic trip, we put a stronger spring etc ...

The end 83 is welded to a tab 91 coming in one piece with the flank 81, on the opposite side and in the same transverse half as the extension forming the fixed contact. The other end 84 of the coil is welded to a conductive connecting piece 92 designed to fit on and block the corresponding connection terminal 32. The part 92 has an inclined part to take account of the orientation of the end 84 in order to ensure satisfactory electrical and mechanical connection. The rigid assembly thus formed is easy to set up precisely. For reasons of the internal geometry of the device housings, the fixed contact with the electrode, and the conductive part, with the terminal, are located on the same side of the magnetic sub-assembly.

Alternatively, (Figures 12 and 13), the coil 33 could also have, instead of the end 83, an end 83 'folded so as to be directly welded to the extension forming the fixed contact, as close as possible to this, as well as possibly, in place of the end 84, one end folded towards the connection terminal (not shown).

The sub-assemblies 31 thus described correspond to a type of configuration, in this case with neutral on the left. For the other type of configuration, use a cylinder head and a symmetrical coil of the previous ones so as to keep the interior arrangement.

Claims (14)

Magnetic trip device for circuit breaker, in particular for phase and neutral circuit breaker, of the type comprising on the one hand an induction coil (33) which is associated with a movable core (89) with striker (90) and return spring in a insulating sheath (87) and which is mounted longitudinally in a cylinder head (33) having first and second flanks (80, 81) facing each other, the first flank (81) being provided with a core fixed (85) in which the striker (90) is guided, the spool (33) being provided with a first end (83) for its connection with the cylinder head (34) and with a second end (84) for its connection to a terminal (32) of the circuit breaker, and on the other hand, a fixed contact (35) extended by an arc switching electrode (37), characterized in that the cylinder head (34) has a general U-shape with a longitudinal arm (82) connecting the two flanks (80, 81) facing each other and is formed by cutting and bending a metal strip of so as to integrate the fixed contact (35) and the switching electrode (37). Magnetic trip device according to claim 1, characterized in that the fixed contact (35) comes in the extension of said first flank (81) and has a width less than that of this flank. Magnetic trip device according to claim 2, characterized in that the fixed contact (35) comes substantially in the extension of a part located in a transverse half of the first flank (81). Magnetic trip device according to claim 3, characterized in that the second end (84) of the coil (33) intended to be connected to the connection terminal (32) of the circuit breaker, is located on the same side as the fixed contact (35) . Magnetic trip device according to any one of Claims 1 to 4, characterized in that at least one of the two ends (83, 84) of the coil (33) is straight. Magnetic trip device according to claim 5, characterized in that the first end (83) of the coil (33) is straight and is welded on a lug (91) extending from the first flank (81), this lug (91) being oriented parallel to said first straight end (83). Magnetic trip device according to claim 6, characterized in that the tab (91) comes from the cutting of the longitudinal arm (82) of the cylinder head (34) and is located on the side opposite to the fixed contact (35). Magnetic trip device according to any one of Claims 1 to 4, characterized in that the first end (83) of the coil (33) is folded so as to be welded directly to the extension forming a fixed contact (35) and switching electrode (37), as close as possible to said fixed contact (35). Magnetic trip device according to any one of Claims 1 to 8, characterized in that the second end (84) of the coil (33) is welded to a conductive piece (92) of rigid connection and able to come into engagement rigidly with the connection terminal (32) of the circuit breaker. Magnetic trip device according to any one of claims 1 to 9, characterized in that the second end (84) of the coil (34) is straight. Magnetic trip device according to claim 10, characterized in that the connecting piece (92) has a part intended for the welding of the second coil end, part which is inclined to take account of the direction of said end (84). Magnetic trip device according to any one of Claims 1 to 11, characterized in that the fixed core (85), the movable core (89), the striker (90), its return spring and the insulating sheath (87) form a pre-assembled sub-assembly, slid and clipped from behind (80). Magnetic sub-assembly characterized in that it comprises, in the form of a rigid assembly, a magnetic trip device according to any one of claims 1 to 12 with connection piece (92) and connection terminal (32). Circuit breaker characterized in that it comprises a magnetic trip device according to any one of Claims 1 to 12 or a magnetic sub-assembly according to Claim 13.

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