EP1513180B1 - Electric fuse link - Google Patents

Abstract

A housing contains a working fusible conductor connected to contact blades (3). A fusible indicator conductor (24) is directly fixed in one blade holding plate (10) by a clamp connection. The blade holding plate has a projection, and the fusible indicator conductor is clamped between the projection and the remaining section (27) of the blade holding plate. An independent claim is included for a further fuse link.

Description

The invention relates to a fuse link, in particular for low-voltage high-performance fuses (NH fuses), with an open on opposite sides housing, connected to the housing cover plates for closing the openings of the housing, arranged in the region of the inside of the respective cover plate knife plate for Bearing a contact blade, which passes through an opening in the cover plate to the outside, wherein in the housing a working fusible conductor is arranged, which is conductively connected to the contact blades, and with a display device which has a display element in the region of the outer surface of a cover plate, wherein the display element is arranged by a arranged in the housing, arranged electrically parallel to the working fusible conductor, wire-shaped display fusible link is fixed in a prestressed position, the display fusible link engages one end on the display element and the other end is fixed by means of a clamping connection in the region of a knife-holding plate.

Fuse-links for NH fuses are widely known from the prior art.

A fuse link of the type mentioned is known from DE-A-100 05 145. He has from electrically insulating material existing cover plates. The respective contact blade is provided with lugs, pass through the openings in the associated cover plate and connected to the cover plate facing the knife plate. Each knife holder plate is provided with a through hole into which a sealing plug is inserted. The one sealing plug, in the region of a knife-holding plate which is assigned to the display element, is provided with a central hole through which the indicator melting conductor is inserted. The outwardly projecting end of the display melt conductor is inserted into a slot of the display element and thus clamped to this. The other end of the display melting conductor is pulled through before the pressing of the sealing plug into the hole of the knife holder plate, through this, the filling opening for the erosion representing opening and fixed by means of a fastening element. Subsequently, the receiving space of the housing is filled with extinguishing sand. Then the filling opening is closed by means of the sealing plug. The indicator fusible conductor is thus clamped between the sealing plug and the blade holding plate.

In this known from the prior art fuse link, the respective blade holding plate in the region of the opening, which serves to receive the sealing plug, provided with an outwardly directed, thus away from the housing annular flange. This extends from the main surface of the respective blade holder plate. The outwardly directed flange ensures a conductive connection of the respective blade-holding plate to the display fusible conductor or the display element. This is important in terms of non-conductive cover plates.

A disadvantage of this fuse link that its design in the field of both knife holding plates and the local contact areas of the display is structurally quite complex and also requires a large installation effort. Thus, the sealing plug in the region of the display element not only serves to fasten the display element, but also to make contact with the associated knife holding plate. In this area, moreover, the indicator fusion conductor is to be guided by the blade holding plate, concretely to thread through the hole in the sealing plug, which is inserted into the opening of the blade holding plate. This procedure is extremely expensive. The other end of the display melting conductor is first to fix before pressing the sealing plug, by means of a fastener. Only after filling the housing by means of extinguishing sand, the sealing plug can be inserted into the opening of the associated knife-holding plate and the cover plate associated therewith; only when the plug is plugged in, the indicator fusion conductor is fixed there. For fixing thus at least the sealing plug is required, also for pre-fixing the fastener. This procedure is very complicated, so the structural complexity for the automated production of such fuse inserts is considerable.

In DE-A-197 44 535 a fuse link for NH fuses is described, in which the display fusion conductor in the region of a cover plate to an intermediate plate, for example by a spot weld, fixed and to which, arranged on this base plate contact blade is connected. In an opening of the other cover plate, an insulating bush is inserted, through which the display melting conductor is passed. The opening opens into a recess of this cover plate. A display element of a display device is inserted with a base leg in this recess and fixed there by squeezing the lateral edge of the recess. One leg of the display element is provided with a breakthrough or slot through which the display fusion conductor, which is formed as a thin wire, is passed. The indicator fusible conductor is spot-welded to the top of this leg. The cover plate can also be non-conductive in this fuse. In this case, it is proposed to provide the display element with a shaped nose or fillet which directly contacts the contact plate associated with the display element when the display fuse is stretched.

Electrical fuse links for NH fuses are also known from DE-C-42 36 212 and DE-A-32 03 211.

The object of the invention is to develop a fuse link of the type mentioned so that with minimal manufacturing and assembly costs, a secure and permanent electrical contacting of the display device is ensured.

The object is achieved in a fuse link of the type mentioned above in that the display fusion conductor is fixed by means of the clamping connection directly in the one blade holder plate.

According to the invention it is thus provided that the knife holder plate itself serves to set a display melting conductor. There is thus no further component for fixing the display melt conductor to the knife-holding plate necessary, thus in particular no sealing plug, which brings about the clamping connection between this and the knife-holding plate. It is not Provide welded joint, which brings about the connection between display melt timer and knife holder plate. The connection of the display melting conductor by means of a sealing plug has the disadvantage that the pressing-in direction of the plug is opposite to the pulling direction of the indicating melting conductor and accordingly a check is required as to whether the indicating element is properly tensioned. This also applies to a welded connection of the indicator melting conductor. Apart from this, there is the danger that if the display melting conductor is excessively heated, when it is fastened to the associated knife holding plate, the indicator melting conductor in this area will be unintentionally severed.

The invention proceeds in a very simple way, in which the determination of the display melting conductor takes place directly in the knife holder plate. This type of connection of the knife-holding plate and the indicator-melting conductor can be accomplished particularly easily if the knife-holding plate has a projection, wherein the indicator-melting conductor is clamped between the projection and the remaining portion of the knife-holding plate. In principle, such a clamping connection is sufficient, as can be achieved by a tapering gap between the knife-holding plate and the projection. Thus, the tightened indicator fusion is moved into this gap and is permanently held in this position.

It is regarded as more advantageous if the connection of the indicator melting conductor and the knife holding plate is insoluble. This is preferably done in that the clamping connection is formed by deforming the projection in the direction of the remaining portion of the knife-holding plate. A deformation process of the knife holder plate thus leads to the permanent connection of the display fusion conductor and the knife holder plate.

The knife holder plate can be designed as a very simple component. Thus, it is possible to achieve the purpose of the invention to form the knife plate as a whole as a flat component. The projection sticks out in this case slightly away from the remaining portion of the knife holder plate. In principle, it would also be conceivable to arrange the projection oriented out of the main plane of the knife plate. In the former case, the display fusible conductor is held in the region of the front edge of the knife-holding plate, in the second-mentioned case in the region of the main surface of the knife-holding plate between the latter and the optionally deformed projection.

From the aspect of a particularly simple generation of the clamping connection between the display melting conductor and knife holder plate, it is considered advantageous if the clamping plate adjacent cover plate, in the alignment of the clamping connection, is provided with a through hole which can be closed by means of a plug. In this design, with largely mounted fuse link, prior to filling with extinguishing sand, the display fusible link, which is fastened with its other end to the display element, inserted through the hole in the cover sheet and in this case positioned between the projection and the blade holder plate. In the case of a display fusion conductor tensioned by means of a tool, the projection can then be acted upon by the through hole by means of a further tool, such that the projection is pressed against the remaining portion of the knife holding plate, thereby clamping the display fusion conductor between itself and the remaining portion of the knife holding plate. After filling the housing with extinguishing sand, a sealing plug can be inserted into this through hole. The function of the sealing plug is thus independent of the fixation of the display melting conductor in the region of the knife-holding plate.

According to a preferred development of the invention, it is provided that the knife holding plate adjacent to the display element has a knife holding plate section bent out of its main face or a stamping from this main face, wherein the knife holding plate section or the stamping passes through a through hole in the cover plate facing this knife holding plate and in biased position fixed display element contacted directly electrically, wherein the display fusible conductor is arranged next to the bent-out blade holder plate portion or the expression.

This development thus relates to the safe and permanent electrical contacting of the display device in the region of the other end of the fuse link.

In this development, the deflected blade holding plate section or the expression of the knife holder plate comes exclusively to the contact function. This area is therefore in no functional connection with the implementation of the display melting conductor through the knife-holding plate in the region of a hole which can be closed by means of a plug, as described for DE-A 100 05 145. There, the knife holder plate is provided with a ring portion which is inserted into a hole of the associated cover plate, wherein the outer end edge of the annular portion is aligned with the maximum maximum outer surface of the respective cover plate. The ring section passes through the indicator fusible conductor which is inserted through a hole in a sealing plug. By means of this sealing plug, the display element is attached to the knife holder plate by the sealing plug passing through a hole in the display element is pressed into the hole of the knife holder plate in the region of the ring portion. In the case of the further development, however, the indicator melting conductor is arranged locally next to the bent-out knife holding plate section or the stamping out of the main surface of the knife holding plate. A plug for closing an opening in the region of this cover plate or this Messerhalteplatte is not required. This considerably simplifies the manufacture and installation of the fuse link.

According to a preferred embodiment, it is provided that the display fusion conductor outside of the display element adjacent Knife plate is arranged. In this configuration, the deflected blade holding plate portion or the expression of the blade holding plate to the contact function regarding the display element, while the display melting conductor, which acts on the display element, based on the region of the blade holder plate, is disposed outside of this blade holder plate.

The indicator fusible conductor is thus not passed through a hole in this blade holding plate, but past the blade holding plate. The manufacture and mounting of the fuse link in this area is simplified, because the assembly operations of this knife-holding plate and the display melting conductor can be done separately. It is not necessary to thread the indicator fusion conductor through a hole in a sealing plug inserted into the blade holding plate. Instead, the through hole in the cover plate facing the knife holder plate must be designed only in accordance with the dimensions of the bent-out knife holder plate section or the design of the knife holder plate.

The variant of the knife holder plate with the bent-out blade holder plate section is of particular advantage. Since only a relatively small embossing height can be achieved by means of an expression, the bending out of a section, depending on the bent-out length, allows the use of the knife holding plate for cover plates of different and in particular relatively large wall thickness. In case of identical arrangement of the through-hole, only the protruding portion of the blade holding plate is more or less shortened and bent out at the same position according to the thickness of the cover plate, whereby the respective blade holding plate portion has the desired different length corresponding to the thickness of the cover plate. A particularly simple design of such a knife holder plate is characterized by a right angle to the main surface of the knife holder plate bent knife holding plate section.
Such a knife-holding plate having an outwardly bent portion can be easily formed from a flat starting plate.

According to a preferred embodiment of the invention it is provided that the respective cover plate is not conductive. It thus has in particular voltage-insulated grip bottles. The contacting of the display device thus takes place both in the region of the display element and the display melt conductor directly to the blade holding plates out and from there to the contact blades. Switches off the fuse, therefore, a secure melting of the indicator melt is guaranteed. Advantageously, in the case of the fuse insert, the display element extends from the area of the outer surface of the associated cover plate to the outer surface of the fuse link. It is thus in the fuse link to such a front and center detector, as it is known for example from DE-A-100 05 145 and DE-A-197 44 535. Preferably, however, the display element is loosely attached to the cover plate, is thus not connected to the cover plate. Such a variant is basically described in DE-C-1 034 751.

Further features of the invention are set forth in the subclaims, the description of the figures and the figures themselves, wherein it is noted that all individual features and combinations of individual features are essential to the invention.

Figur 1

ein Längsmittelschnitt durch eine erste Ausführungsform des erfindungsgemäßen NH-Sicherungseinsatzes, ohne Gehäuse, bei gespanntem Anzeigeelement,

Figur 2

einen Schnitt gemäß Figur 1 durch den NH-Sicherungseinsatz, bei ausgelöstem Sicherungseinsatz, somit bei durchtrenntem Anzeigeschmelzleiter und entspanntem Anzeigeelement,

Figur 3

eine Ansicht III der einen Messerhalteplatte gemäß Figur 2, veranschaulicht vor dem Umformen dieser Messerhalteplatte zwecks Klemmen des Anzeigeschmelzleiters,

Figur 4

die in Figur 3 gezeigte Messerhalteplatte nach deren Umformung und somit Klemmung des Anzeigeschmelzleiters,

Figur 5

eine räumliche Ansicht der anderen Messerhalteplatte des NH-Sicherungseinsatzes,

Figur 6

für eine zweite Ausführungsform der Erfindung Teile des NH-Sicherungseinsatzes in einer räumlichen Ansicht, nämlich im Wesentlichen die eine Deckplatte mit Kontaktmesser und Anzeigeelement sowie die andere Deckplatte mit Messerhalteplatte und zwischen diesen angeordneter Dichtscheibe,

Figur 7

eine räumliche Ansicht der nur bezüglich der Deckplatte zur Aufnahme des Anzeigeelementes, des Gehäuses und des zwischen Deckplatte und Gehäuse angeordneten Dichtscheibe dargestellten NH-Sicherungseinsatzes,

Figur 8

für diese Ausführungsform in einer räumlichen Ansicht eines Mittellängsschnittes das Gehäuse, die Deckplatte, das Anzeigeelement und die Messerhalteplatte und

Figur 9

eine Explosionsdarstellung von Messerhalteplatte, Dichtscheibe und Deckplatte für den in Figur 8 veranschaulichten Bereich des NH-Sicherungseinsatzes.

In the figures, the invention is illustrated by means of an embodiment, without being limited to these. It shows:

FIG. 1

a longitudinal center section through a first embodiment of the invention NH fuse-link, without housing, with a tensioned display element,

FIG. 2

a section according to Figure 1 by the NH fuse-link, with triggered fuse link, thus with severed display melting conductor and relaxed display element,

FIG. 3

FIG. 2 shows a view III of a knife-holding plate according to FIG. 2, before forming this knife-holding plate in order to clamp the indicator melting conductor,

FIG. 4

the knife holding plate shown in Figure 3 after the forming and thus clamping of the display melting conductor,

FIG. 5

a spatial view of the other knife holder plate of the NH fuse-link,

FIG. 6

for a second embodiment of the invention, parts of the NH fuse-link in a three-dimensional view, namely essentially the one cover plate with contact blade and display element and the other cover plate with knife-holding plate and arranged between these sealing disc,

FIG. 7

a spatial view of the only with respect to the cover plate for receiving the display element, the housing and arranged between the cover plate and housing sealing washer shown NH fuse-link,

FIG. 8

for this embodiment, in a three-dimensional view of a central longitudinal section of the housing, the cover plate, the display element and the blade holding plate and

FIG. 9

an exploded view of knife holder plate, sealing washer and cover plate for the illustrated in Figure 8 range of NH fuse-link.

The embodiment according to FIGS. 1 to 5 differs from those according to FIGS. 6 to 9 essentially in that, in the embodiment according to FIGS. 1 to 5, the display melting conductor is guided through a hole of the knife holding plate which is adjacent to the display element. In the embodiment according to FIGS. 6 and 9, the indicator fusible conductor is arranged outside this knife holder plate.

In the following description, reference will first be made to the embodiment of FIGS. 1 to 5:

On the side of the display element, the NH fuse-link has a knife holder plate 1, which is provided with two substantially rectangular in cross-section openings 2 for receiving pins 3 of a contact blade 4. Adjacent to the knife holder plate 1, a cover plate 5 consisting of insulating material is arranged, which accommodates a metallic gripping tab 6 at the top, which is thus designed as an insulated gripping tab. Between the cover plate 5 and the knife holder plate 1 there is a sealing disc 7 formed of non-conductive material, the cover plate 5 is fastened by means of four screws on a hollow cylindrical housing formed as a ceramic body, as illustrated by the reference numeral 9 for the second embodiment in Figures 7 and 8 is.

On the other hand, the NH fuse-link according to a knife holder plate 10 with openings 2, a contact blade 4 with pin 3, a cover plate 11 with handle tabs 6, a sealing washer 7 and screws 8 for connecting the cover plate 11 with the housing 9. The knife holder plate 10 and the cover plate 11 are therefore designated differently than the knife holder plate 1 and the cover plate 5, because these components, depending on the side of the NH fuse-link, are designed differently in this embodiment.

For connecting the respective contact blade 4 with the knife-holding plate 1 or 10, the free ends of the pins 3 inserted into the openings 2 of the knife-holding plate 1 or 10 are caulked. The actual contact blade 4 passes through an opening of the sealing disc 7 and the cover plate 5 or 11 which is adapted to the cross section of the contact blade. The respective blade holding plate 1 or 10 is held by fixing the cover plate 5 or 11 to the housing 9 by means of the screws 8 is clamped between the cover plate 5 and 11 and a return of the housing.

As can be seen from the illustration of FIG. 5, the knife holding plate 1 has a knife holding plate section 13 bent out of its main section 12. This is arranged approximately at right angles to the main section 12. The bend is located in the area of the knife holder plate 1 which is adjacent to the pull tab 6. Adjacent to the blade holding plate portion 13, the main portion 12 is provided with a through hole 14.

Between the grip tab 6 and the contact blade 4, the cover plate is provided with a recess 15. The length of the knife-holding plate section is dimensioned so that its free end face 16 projects beyond the cover plate 2 in the region of the recess 15 of this cover plate. This makes it possible for the knife-holding plate 1 to contact a display element 17 of a display device 18 in the area of the end face 16 in a planar manner as a z-shaped spring. The display element 17 is formed by the, a spring-forming legs 19, 20 and 21. The leg 19 rests freely on the end face 16 of the knife holder plate 1. The display element 17 continues from the leg 21 into a further leg 22. The visible leg 21 includes the function of the overhead detector of the NH fuse-link, the leg visible from the side 22, the function of the center detector. In this respect, the leg 22, which is provided with a marking acts in a known manner with a hole 23 in the housing 9, as illustrated for example to Figure 8 concerning the further embodiment together.

Part of the display device 18 also forms a trained as a wire display fusion conductor 24. This is electrically arranged in parallel to a not further illustrated, well-known from the prior art working fuse. This working fusible conductor is guided through the housing 9 and connected to the pin 3 of the contact blade 4.

The display melting conductor is connected at one end to the display element 17 in the region of the transition of the legs 21 and 20. Thus, for example, the leg 21 has a slot into which the indicator melting conductor 24 is clamped, preferably after repeated wrapping of the display element 17 in the region of the leg 21. In the area of the other cover plate 11, the indicator melting conductor 24 is held directly in the blade holding plate 10. This differs from the knife holder plate 1 in that it does not have a knife holder plate portion 13 bent out of the main portion 12 and also no hole 14. Rather, the knife holder plate 10 adjacent to the pull tab 6 has a recess 25. In the region of the lower limit of this recess, the indicator melting conductor 24 is held in the knife holding plate 10 by means of a clamping connection. Thus, the knife-holding plate 10 has a projection 26, wherein the display fuse between the projection 26 and the remaining portion 27 of the knife-holding plate 10 is clamped. Fig. 3 shows the state before jamming, wherein a sufficiently large gap is formed between the projection 26 and the remaining portion 27 of the blade holding plate 10 to set the indicator fuse 24 in this area of the blade holding plate 10, while Fig. 4 shows the clamped state. In this, the projection 26 has been moved by deformation by means of a tool against the remaining portion 27 of the knife-holding plate 10. The deformation of the projection 26 takes place, as can be understood due to the illustration in Figure 1, from outside the NH fuse-link, by an opening 28 in the cover plate 11 and an aligned opening 29 in the sealing disc 7, a tool in the area the recess 25 of the blade holder plate 10 is guided and takes effect there.

In the position of the display element 17 shown in FIG. 1, which is prestressed by means of the display melt conductor 24, the housing 9 is filled with extinguishing sand and subsequently the opening 28 in the cover plate 11 is closed by means of a sealing plug.

FIG. 2 shows the state of the NH fuse-link, once again shown without a housing and extinguishing sand in it, after the fuse-link has melted through, thus after melt-through of working fuse and indicator melting conductor 24. The melting of the indicator melting conductor 24 causes the display element 17 to relax and both its legs 21 and its legs 18 is moved, with the result that the triggering of the fuse can be recognized both the front side and from the side.

In the second embodiment of the invention illustrated in FIGS. 6 to 9, parts which basically correspond to those of the first embodiment according to FIGS. 1 to 5 in construction and operation are designated by the same reference numerals.

In the embodiment according to FIGS. 6 to 9, the knife holding plate 1 has no hole 14, but instead the knife holding plate section 13 is positioned closer to an opening 2 of the knife holding plate 1 facing the latter and the display melting conductor 18 is guided outside the knife holding plate 1 and with the display element 17 in FIG Area of the leg 21 connected. The corresponding opening in the cover plate 5 for passing the knife-holding plate section 13 is designated by the reference numeral 30 in FIG. 7, the small, bore-like opening for passing through the wire-shaped display fusion conductor 24 by the reference numeral 31 in this figure. For better understanding, only the components essential for the respective explanation of the figure are illustrated in FIGS. 6 to 9.

Claims (13)

1. A fuse link, in particular for low-voltage, high-breaking-capacity fuses (LV HBC fuses), comprising a case (9), which is open on opposite sides; cover plates (5, 11) attached to the case (9) for sealing the openings in said case (9); a blade-holding plate (1, 10) disposed in the region of the inside of each cover plate (5, 11) for supporting a contact blade (4) which passes through an opening in said cover plate (5, 11), a working fuse element, which is conductively connected to the contact blades (4), being disposed in said case (9); as well as comprising indicator means (18) which, in the region of the outer face of a cover plate (5), comprise an indicator element (17), said indicator element being fixed in a prestressed position by an indicator fuse element (24) which takes the form of a wire and is disposed inside the case so as to be electrically in parallel with the working fuse element, one end of the indicator fuse element (24) acting on the indicator element (17) and its other end being fixed by means of a clamped joint in the region of one blade-holding plate (10), characterized in that the indicator fuse element (24) is directly fixed to one blade-holding plate (10) by means of the clamped joint.
2. A fuse link according to Claim 1, characterized in that the blade-holding plate (10) has a projection (26), the indicator fuse element (24) being clamped between said projection (26) and the remaining portion (27) of the blade-holding plate (10).
3. A fuse link according to Claim 1 or 2, characterized in that the clamped joint is formed by a notch located between the projection (26) and the remaining portion (27) of the blade-holding plate (10) and by the indicator fuse element (24) being inserted into said notch.
4. A fuse link according to one of Claims 1 to 3, characterized in that the clamped joint is formed by deformation of the projection (26) towards the remaining portion (27) of the blade-holding plate (10).
5. A fuse link according to one of Claims 1 to 4, characterized in that, at least in the region of the projection (26) and of the area adjoining this of the remaining portion (27) of the blade-holding plate (10), the blade-holding plate (10) is formed as a flat structural member.
6. A fuse link according to one of Claims 1 to 5, characterized in that, adjacent to the clamped joint, the cover plate (11) is provided with a through hole (28) which is disposed so as to be in line with the clamped joint and which can be sealed by means of a plug.
7. A fuse link according to one of Claims 1 to 6, characterized in that, adjacent to the indicator element (17), the blade-holding plate (1) has a portion (13) bent out from its main portion (12) or else it has an embossment, the portion (13) or embossment passing through a hole (30) in the cover plate (5) which faces this blade-holding plate (1) and establishing direct electrical contact with the indicator element (17) fixed in the prestressed position, the indicator fuse element (24) being disposed close to the portion (13) or embossment of the blade-holding plate.
8. A fuse link according to Claim 7, characterized in that the indicator fuse element (24) is disposed outside the blade-holding plate (1) adjoining the indicator element (17).
9. A fuse link according to Claim 7 or 8, characterized in that the portion (13) of the blade-holding plate has a length which corresponds to at least the thickness of the facing cover plate (5) in its region adjoining the portion (13) of the blade-holding plate.
10. A fuse link according to one of Claims 7 to 9, characterized in that the portion (13) of the blade-holding plate is bent out at right angles to the main portion (12) of the blade-holding plate (1).
11. A fuse link according to one of Claims 1 to 10, characterized in that the respective cover plate (5, 11) is not conductive.
12. A fuse link according to one of Claims 1 to 11, characterized in that the indicator element (17) extends from the region of the outer face of the cover plate (5) to the surface of the fuse link.
13. A fuse link according to one of Claims 1 to 12, characterized in that the indicator element (17) rests loosely against the cover plate (5).

Images