EP1560245B1 - Cartridge fuse particularly for a low-voltage high-power fuse - Google Patents

Description

The invention relates to an electrical fuse link, in particular for a low-voltage high-performance fuse, with a arranged in a tubular shell body working conductor and a display device for displaying the operating conditions "ready" and "triggered" the fuse link, consisting of an electrically parallel to the working smelting conductor switched indicator fusion and a spring element connected to a characteristic element for optically displaying the operating conditions, which is held by the display fuse in the operating state "under power" under tension of the spring element.

From the German utility model DE 298 07 928 U1 is already an electrical fuse link, in particular a low-voltage high-performance fuse link, with a arranged in a housing working fuse and a display device known. The housing consists essentially of a tubular shell body in which runs centrally the working fusible conductor and whose ends are closed with an upper and a lower end plate. To each of these end plates, a contact blade is arranged, which extends at right angles and outwards from the end plates. The two contact blades are electrically connected to the working smelting conductor. With these contact blades, the fuse link is electrically inserted into a fuse housing and held there in appropriate spring clips mechanically and releasably. To handle the fuse in the usual manner, the end plates are extended over the shell body to the front of the fuse link and form handle tabs on which a handle can be placed.

The working flux conductor described above is monitored by a display device. This display device has a display fusion conductor, which is formed as a wire and is arranged electrically parallel to the working fusible conductor. The display device further consists of a spring element and a characteristic element, which is connected to the spring element. The indicator melting conductor has the task to bias the spring element. For this is the indicator fusion conductor with one end with the spring element and with the other end with the inside of the lower end plate spot welded. The spring element is supported on the opposite end of the indicator element on the upper end plate and is in the relaxed state z-shaped. When the indicator fusible link melts, the spring element can relax and the strip-shaped indicator element is moved outward with respect to the upper side of the upper face plate, so that the release of the fuse can be recognized from the outside. For this purpose, two colored markings are arranged on the indicator element, which are visible in the region of the upper end plate and the front of the fuse link. In the area of the jacket body, the indicator element is guided in a bore which extends downwards from the upper face plate and ends in the region of the middle of the jacket body. Transverse to this bore extends in the end region of a transverse channel which terminates at the front side of the jacket body and thus allows a clear view of the lower mark of the Kennmelderelements. In the tripped state, the indicator element is pulled upwards out of the bore in the sheath body by the spring element, so that one of the two markings on the indicator element is visible from the front side and the lower marking on the indicator element is no longer visible through the transverse channel.

This embodiment of the display device with a characteristic element whose markings are visible from the front side and also the front side of the fuse link is also referred to as a double indicator. The aforementioned low-voltage high-performance fuses are also called NH fuses and their inserts NH cartridges.

Furthermore, from the DE 298 14 737 U1 a fuse link for NH fuses known, the Kennmelderelement consists of a foil strip made of polyethylene. To connect the Kennmelderelements with a spring element for triggering the fuse link of the film strip is simply pressed onto a mandrel of the spring element, so that the film strip is pierced by the mandrel. The mandrel is provided with undercuts to prevent slipping of the foil strip from the mandrel.

Furthermore, the European patent describes EP 1 051 719 B1 another NH cartridge with a double indicator. There is the Kennmelderelement off Spring band steel made and goes seamlessly into the spring element. above. The spring element is thus integrated in the indicator element. In order to facilitate the assembly of the Kennmelderelements, whose beginning of the spring element area is already connected to a plug. Also, the indicator fusible link is already connected to the spring element and guided through the plug. The indicator element, the plug and the indicator melting conductor thus form a preassembled unit. Thus, this assembly can be connected to the NH cartridge via the plug, namely by plugging the plug into a filling opening, which is usually present in the front plate of the NH cartridge. The spring element region facing away from the end of the indicator element is in this case then inserted into a further bore with a view opening in the front side of the jacket body.

In the DE 196 44 904 a fuse link with a working fuse and a wire-shaped fuse conductor (detector wire) is described for a reporting device. The working fusible conductor and the detector wire are both arranged in a sleeve-shaped insulating body, whose end faces are covered with closure plates. In an embodiment according to Figures 16 and 17 of D1, the detector wire is passed through the insulating body, wherein it is fixed at one end with a sleeve in the closure plate and is guided at the other end through the closure plate to a firing pin and clamped to this is. The firing pin serves as a characteristic element. Between the firing pin and the closure plate, a spring is provided, which is tensioned in an operational state, since the detector wire pulls the firing pin against the spring force in a sleeve in which the spring is arranged. As soon as the detector wire melts, the firing pin is pushed out of the sleeve by the spring force. Accordingly, in the fuse link after the DE 196 44 904 the detector wire attached to the indicator element, which is movably mounted in the insulating body, or the sleeve.

Based on this prior art, the present invention based on the object to provide a fuse link, in particular for NH fuses, whose display device has a simple construction.

This object is achieved by an electric fuse link with the features of claim 1. Advantageous embodiments of the invention are specified in claims 2 to 13.

According to the invention, in an electrical fuse link, in particular for a low-voltage high-performance fuse, with a arranged in a tubular sheath body working conductor and a display device for displaying the operating states "ready" and "triggered" the fuse link, consisting of an electrically parallel to the working smelting conductor switched display fusion and a connected to a spring element indicator element for optically displaying the operating conditions, which is held by the display fusible in the operating state "under tension" of the spring element, a simple construction achieved in that the display fuse with one end in the region of the indicator element to a clamping the jacket body is fixed or clamped to the indicator element. It is thereby achieved in a particularly advantageous manner that the upper end of the indicator melting conductor can be connected in a particularly simple manner to the jacket body in the area of the indicator element or the indicator element. Thus, can the otherwise usual spot welding of the display melting conductor with the identification element omitted.

It is particularly advantageous that the display melting conductor is wire-shaped and acts directly on the upper end of the Kennmelderelementes. The wire-shaped design facilitates its clamping attachment.

In a preferred embodiment, the spring element is designed as a helical spring. As a result, a particularly high switching force of the characteristic element is achieved; an actuation of micro switches over this is possible.

In a first embodiment of the invention, it is provided that the display melting conductor is fastened with the end in the region of the characteristic element by means of a holding element in a clamping manner on the casing body. In this case, the display melting conductor is guided over the identification element and thus holds this. In the run-up to assembly, the indicator element and the indicator fusion conductor need not yet be connected to one another.

It is also provided that the spring element is arranged in the wall of the jacket body. Thus, the spring element is housed protected and can not be damaged by the subsequent assembly operations and during operation of the fuse element. The reliability of the display device of the fuse link is thus retained.

In a preferred embodiment, it is provided that the spring element is supported in the jacket body and is fastened outside the ends of the identification element to the identification element.

It is also advantageous that the indicator element is rod-shaped, is slidably disposed in a bore of the jacket body between the operating states "ready" and "triggered" and in the operating state "triggered" protrudes from the end face of the jacket body. The rod-shaped design of the indicator element allows in addition to the visual indication of the triggering state by its stiffness and an actuation of micro-switches for a remote display.

In one embodiment, it is provided that the holding element in the opening of the Bore is inserted and the upper end of the indicator fusible conductor is clamped between the holding member and the bore.

The fact that the spring element is aligned with its direction of action of force parallel to the direction of displacement of the indicator element, the spring force is transmitted to the rigid detector rod particularly well. An actuation of microswitches can thus be done safely.

A constructive alternative provides that the holding element is designed as a U-shaped clamp, which is inserted with a leg in the opening of the bore and the upper end of the display melting conductor is clamped between the holding member and the bore.

In this embodiment, therefore, all the components of the display device are in close contact with the sheath body and can be completely pre-assembled before the sealing plates and the end plates are bolted to the shell.

In a second embodiment of the securing element is advantageously provided that the display melting conductor is led out via a sleeve-shaped guide member of the sheath body. A hole in the shell body exclusively for the indicator melting conductor can thus be omitted.

Particularly advantageous is provided that the spring element in the operating state "ready for operation" is arranged almost completely in the guide element. Thus, the spring element is arranged in a particularly space-saving manner in this operating state and does not lead to an increase in the size of the display device. Also, thus the spring element is housed protected and can not be damaged by the subsequent assembly operations. The reliability of the display device of the fuse link is thus retained.

Because the guide element is sleeve-shaped, a spring element designed as a helical spring can be accommodated in a space-saving manner in the cavity formed by the guide element. In addition, the usable coil spring is a simple standard component, which also has a sufficient and linearly directed spring force to trigger the Display device has. Also, the coil spring can generate a particularly high switching force that can be used to operate micro-switches.

Particularly advantageously, the spring element is installed such that the spring element is supported in the guide element and its end facing away from the guide element is connected to the indicator element.

In a conventional manner, the sleeve-shaped guide element is inserted in the manner of a plug into an opening of an end plate adjoining the casing body and the opening of the guide element is directed away from the casing body. The thus existing previously unused opening is now used to hold the spring element.

In a preferred embodiment, it is provided that the indicator element is angularly formed with a short leg and a long leg, the long leg is slidably disposed in a guide channel in the front side of the shell body between the operating states "ready" and "triggered" and in the operating state "triggered" protrudes from the front side of the jacket body.

A particularly simple guidance of the indicator element is achieved in that the guide channel in the front side of the jacket body is closed to the outside via a front plate arranged on the front side of the jacket body.

The fact that the spring element is aligned with its direction of force parallel and laterally offset from the direction of displacement of the long leg of Kennmelderelementes, this can be particularly easily moved in the guide channel from the operating state "ready" in the operating state "triggered".

Because the spring element is aligned with its force action direction parallel to the longitudinal extension of the guide element, this can be accommodated in the tensioned state almost completely in the guide element.

In a structurally preferred embodiment of the display melting conductor is wire-shaped and the upper end of the display fusing conductor is directly connected to the short leg of the indicator element.

The above-described embodiment of the display device, in particular of the indicator element, is particularly suitable for displaying the operating state of the fuse link on the front side and on the front side. Basically, only a forehead display is feasible.

It is particularly simple in design terms that the indicator element is designed as a red anodised aluminum strip.

Figur 1

eine Seitenansicht eines Sicherungseinsatzes für NH-Sicherungen in einer ersten Ausführungsform teilweise im Schnitt,

Figur 2

eine Frontansicht des Mantelkörpers des Sicherungseinsatzes gemäß Figur 1,

Figur 3

eine Draufsicht auf einen Mantelkörper des Sicherungseinsatzes gemäß Figur 1,

Figur 4

eine Draufsicht auf eine obere Dichtungsplatte des Sicherungseinsatzes gemäß Figur 1,

Figur 5

eine Draufsicht auf eine obere Stirnplatte des Sicherungseinsatzes gemäß Figur 1,

Figur 6

einen Ausschnitt einer Seitenansicht eines Sicherungseinsatzes für NH-Sicherungen in einer zweiten Ausführungsform teilweise im Schnitt,

Figur 7

eine perspektivische Detailansicht eines Halteelementes des Sicherungseinsatzes gemäß Figur 6,

Figur 8

eine Draufsicht auf einen Mantelkörper des Sicherungseinsatzes gemäß Figur 6,

Figur 9

eine Seitenansicht eines Sicherungseinsatzes für NH-Sicherungen in einer dritten Ausführungsform teilweise im Schnitt,

Figur 10

eine Draufsicht auf einen Mantelkörper des Sicherungseinsatzes gemäß Figur 9,

Figur 11

eine Seitenansicht eines Sicherungseinsatzes für NH-Sicherungen in einer vierten Ausführungsform teilweise im Schnitt,

Figur 12

eine Frontansicht des Sicherungseinsatzes gemäß Figur 11 und

Figur 13

eine Ausschnittsvergrößerung des Sicherungseinsatzes gemäß Figur 11 aus dem Bereich des Kennmelderelementes.

The invention will be explained in more detail with reference to four illustrated in a drawing embodiments. Show it:

FIG. 1

a side view of a fuse link for NH fuses in a first embodiment partially in section,

FIG. 2

a front view of the jacket body of the fuse according to FIG. 1 .

FIG. 3

a plan view of a jacket body of the fuse according to FIG. 1 .

FIG. 4

a plan view of an upper sealing plate of the fuse according to FIG. 1 .

FIG. 5

a plan view of an upper end plate of the fuse link according to FIG. 1 .

FIG. 6

a section of a side view of a fuse link for NH fuses in a second embodiment partially in section,

FIG. 7

a detailed perspective view of a retaining element of the fuse according to FIG. 6 .

FIG. 8

a plan view of a jacket body of the fuse according to FIG. 6 .

FIG. 9

a side view of a fuse link for NH fuses in a third embodiment partially in section,

FIG. 10

a plan view of a jacket body of the fuse according to FIG. 9 .

FIG. 11

a side view of a fuse link for NH fuses in a fourth embodiment partially in section,

FIG. 12

a front view of the fuse according to FIG. 11 and

FIG. 13

an enlarged detail of the fuse according to FIG. 11 from the area of the indicator element.

The FIG. 1 shows a side view of a fuse link 1 for NH fuses partially in section. The fuse link 1 consists essentially of a tubular shell body 2 made of steatite with a rectangular cross section, which limits a cavity 3 for a working conductor 4. The cavity 3, which is located between the working molten conductor 4 arranged centrally in the jacket body 2 and the inner wall of the jacket body 2, is filled with indicated extinguishing sand.

The upper and lower ends of the sheath body 2 are closed with an upper seal plate 5o and a lower seal plate 5u. The sealing plates 5o, 5u are made of an electrically insulating material, such as Prespan or felt and have a size that approximately match the outer dimensions of the sheath body 2. Each of the two sealing plates 5o, 5u is adjoined by an upper and a lower end plate 6o, 6u, which lie flat on the sealing plates 5o, 5u. The two end plates 6o, 6u are made of aluminum. Corresponding to the rectangular cross-section of the sheath body 2, the flat sealing plates 5o, 5u and the end plates 6o, 6u are also rectangular. The sealing plates 5o, 5u and the end plates 6o, 6u are fastened to the casing body 2 via not shown Screws whose shafts in the shell body 2 in holes 2b (see FIG. 2 ) stop. Usually, four screws are provided per end plate 6o, 6u, which are each arranged in the corner regions of the end plates 6o, 6u. On the end plates 6o, 6u, a contact blade 7o, 7u is fixed by caulking or upsetting, which is electrically connected to the working molten conductor 4. The contact blades 7o, 7u have essentially the function releasably secure the fuse link 1 in resilient retaining clips of a fuse housing, not shown, and at the same time to connect electrically with the retaining clips can. In order to facilitate the handling of the fuse link 1, the end plates 6o, 6u are extended beyond the shell body 2 to the front of the fuse link 1 and thus form grip tabs 8o, 8u, to which a handle, not shown, can be attached in the usual way.

Furthermore, the shows FIG. 1 in that associated with the working smelting conductor 4 is a display device 9 via which the state - ready for operation or triggered - can be read from the upper end side and the front side of the securing insert 1. The display device 9 essentially consists of a characteristic element 10, a spring element 11, a holding element 12 and a display melting conductor 13. On the basis of the identification element 10, an operator can optically recognize the state of the fuse link 1. In the FIG. 1 the indicator element 10 is shown in the display state "triggered". The display status "ready" is indicated by dashed lines. The Kennmelderelement 10 is formed as a longitudinal strip of Alubandrolle and one or both sides red anodized over its entire length, so that it can be easily recognized by the operator. In order to be able to move the identification element 10 between its two display states in a defined manner, it is guided in a bore 14. The FIG. 1 clearly shows that the jacket body 2 for receiving the bore 14 in the region of the front side of the fuse link 1 has a greater wall thickness than in the remaining area. This bore 14 is aligned parallel to the longitudinal direction of the jacket body 2 and extends from its upper end to slightly beyond its center. In the region of the lower end of the bore 14, a transverse channel 20, which opens into the front side 2f of the jacket body 2, closes at a right angle. The transverse channel 20 serves as a viewing opening for the operator. If the red indicator element 10 is seen there, the fuse element 1 is ready for operation; if it is not seen, the fuse element 1 is triggered.

Further, this bore 14 is stepped and has a subsequent to the upper end face 2o of the shell body 2 cylindrical upper part 14o and a slot-shaped to form an annular shoulder 14a lower part 14u. The lower part 14u is slit-shaped so that the indicator element 10 in the bore 14 can not rotate. Like from the FIG. 1 As can be seen, a portion of the upper portion 14o of the bore 14 may taper conically towards the lower portion 14u thereof. It is important that the paragraph 14a is maintained, which serves as a support surface for the spring element 11.

The Kennmelderelement 10 is inserted into the formed as a helical spring spring element 11 and the paragraph 14a facing away from the end of the spring element 11 is approximately at 2/3 length of the Kennmelderelements 10 - seen from below - connected to the Kennmelderelement 10. Thus, the spring element 11 is put under tension when the Kennmelderelement 10 is pressed into the bore 14 and thus in its display position "ready". So that the indicator element 10 can not leave the hole in the display state "triggered", the upper end of the spring element 11 is supported on the inside of the upper sealing plate 5o. Accordingly, the dimensions of an opening 5 a provided in the upper sealing plate 5 o for guiding the identification element 10 are adapted to the outer contour of the identification element 10 (see also FIG FIG. 4 ); the spring element 11 with the larger diameter than the characteristic element 10 can not pass through the opening 5a.

The display melting conductor 13 has the task that Kennmelderelement 10 with the spring element 11 in the display state "ready" to hold against the voltage of the spring element 11, as long as the display fuse 13 is not melted in response to the fuse link. For this purpose, the display melting conductor 13 is electrically connected in parallel to the working melt conductor 4. Accordingly, the ends of the display fuse 13 are electrically connected to the upper and lower end plates 6o, 6u. The display fuse 13 is a wire made of nickel. The lower end 13u of the display fusion conductor 13 is fixed to a second spring element 16 by winding, which is inserted in a blind hole 15. This blind hole 15 is located centrally on the bore 14 opposite the lower end face 2u of the jacket body 2u and extends in the longitudinal direction of the jacket body 2. This second spring element 16 has in addition to the above Fixing function also has the task of electrically connecting the display fusion conductor 13 with the lower end plate 6u. For this purpose, an opening 5b is simply provided in the lower sealing plate 5u, through which the second spring element 16 extends in the direction of the lower end plate 6u. Also, on the lower end face 2u of the jacket body 2, starting from the blind hole 15, a groove may be provided through which the indicator melt conductor 13 is guided into the cavity 3 of the jacket body 2. From there, the display fusion conductor 13 is further guided along the inner wall of the shell body 2 to the upper end face 2o, in which also a groove can be provided, which leads from the inside of the shell body 2 to the bore 14. Then the display fusion conductor 13 is guided over the upper end 10o of the characteristic element 10 and attached to the jacket body 2 so taut that the Kennmelderelement 10 is held against the force of the spring element 11 in the display state "ready".

For attachment of the display fusion conductor 13, a holding element 12 is provided, which is formed in a first embodiment as a sleeve with a circumferential collar or flange. This made of brass or aluminum retaining element 12 is dimensioned so that it is pressed from above into the bore 14 and held there by clamping. Before inserting the retaining element 12 in the bore 14 of the display fusible conductor 13 is inserted into the bore and held by mounting of the retaining element 12 by clamping it.

So that the electrical contact between the upper end 13o of the display melt conductor 13 and the upper end plate 6o can also take place, the holding element 12 is made of an electrically conductive material and inserted into the electrically insulating upper sealing plate 5o, a contact element 19 made of copper. About this contact element 19, the holding member 12 is then electrically connected to the upper end plate 6o.

The FIG. 2 shows a front view of the sheath body 2 according to FIG. 1 , For reasons of clarity, the contact blades 7o, 7u are not shown. This figure shows in particular detail the design of the Kennmelderelementes 10 with a central slot 10a at its upper end 10o for receiving and guiding the display melting conductor 13. Furthermore, the Kennmelderelement 10 in Area 2/3 of its length - seen from below - a paragraph 10b, which serves for the clamping attachment of the upper end of the spring element 11 to Kennmelderelement 10. Also can be taken that in a first assembly step, the holding element 12 are pressed with the display fuse 13 in the bore 14, then the previously connected to the spring element 11 Kennmelderelement 10 are inserted through the holding element 12 in the bore 14 until the lower end of the spring element 11 comes to rest on the paragraph 14a. Only by mounting the upper sealing plate 5o the Kennmelderelement 10 is secured with the spring element 11 against falling out of the bore 14.

In the FIG. 3 is a plan view of the upper end face 2o of a jacket body 2 of the fuse element 1 after FIG. 1 shown. This view shows particularly clearly in the bore 14 for the Kennmelderelement 10, the slot-shaped configuration of the lower part 14u of the bore 14, which serves to guide the strip-shaped Kennmelderelements 10. It can also be seen that, in the corner regions of the jacket body 2, bores 2b which extend in each case in the longitudinal direction thereof are arranged on the jacket body 2 for fastening the sealing plates 5o, 5u and the end plates 6o, 6u.

The FIG. 4 represents a plan view of the upper sealing plate 5o of the fuse element 1 FIG. 1 In addition to the holes 17 for the screw connection of the sealing plate 5o with the jacket body 2, the slot-shaped continuation of the bore 14 in the form of the rectangular opening 5a is shown. As described above, the slit-shaped formation allows passage of the characteristic element 10 and support of its spring element 11. Also, the rectangular contact element 19 adjacent to the opening 5a is shown to electrically connect the display fusion conductor 13 to the upper end plate 6o. The central opening 18 serves to carry out the contact blade 7o.

In the FIG. 5 is a plan view of the upper end plate 6o of the fuse element 1 after FIG. 1 to see. Again, the holes 17 are shown for the screw connection of the end plate 6o with the sheath body 2 and the opening 14b for the implementation of the Kennmelderelementes 10. Central is attached to the upper end plate 6o upper contact blade 7o to see. In the area the front side of the upper end plate 6o, the grip tab 8o is shown in more detail for the handle.

In the FIG. 6 is an enlarged detail of a side view of a fuse link 1 for NH fuses in a second embodiment and shown partially in section. In essence, this embodiment differs in the area of the display device 9 shown from the above-described embodiment. For the sake of simplicity, all the same components have been designated by the same reference numerals and in this regard reference is made to the above description. It can be seen that the holding element 12 is not formed here as a sleeve with a collar but as a U-shaped bracket made of a spring steel strip with a short leg 12 a and a long leg 12 b. Like the sleeve-shaped holding member 12 according to the first embodiment, the U-shaped holding member 12 according to the second embodiment has the task of attaching the upper end 13 o of the display fusion conductor 13 to the jacket body 2. For this purpose, the holding member 12 is pushed with its u-shaped opening 12c on the remaining between the upper part 14o of the bore 14 and the front side 2f of the sheath body 2 web 2a of the sheath body 2 and held there by clamping. Previously, the upper end 13o of the display melt conductor 13 is pulled through an opening 12d in the flange part 12e and guided into the bore 14 at least its upper part 14o (see also FIG FIG. 7 ). The opening 12d in the flange part 12e is located adjacent to the short leg 12a and centrally in the flange part 12e. This aperture 12d is produced by punching out a pin 12f from the flange part 12e, which is then erected relative to the flange part 12e and thus in extension of the short leg 12a extends. This pin 12f replaces the contact element 19 known from the fuse element 1 according to the first embodiment, since the indicator fusion conductor 13 is thereby electrically connected to the inside of the upper end plate 6o. The FIG. 6 Here, it is clear that the pin 12f extends outside of the upper seal plate 5o toward the upper end plate 6o and contacts them.

Since the holding element 12 is a U-shaped clamp made of a spring steel strip and thus the inserted into the bore 14 long leg 12b has a flat bearing surface, the upper part 14o of the bore 14 is corresponding customized. Thus, the upper part 14o of the bore 14 has a semicircular cross-section, the straight part of which forms the inside of the web 2a. In addition, the long leg 12b can be inserted into the inside of the web 2a with respect to the remaining upper part 14o, so that the spring element 11 can not catch on the long leg 12b. In addition, in this embodiment, the upper part 14o of the bore 14 has a slight conical taper in the direction of the shoulder 14a.

To clarify the specific embodiment of the retaining element 12 in the embodiment according to FIG. 6 show the FIG. 7 Hereof a perspective detail view. As before to the FIG. 6 described, distinguishes the bracket-shaped holding element among others by the pin 12f with the associated opening 12d. In addition, at the lower end of the long leg 12b inwardly to the opening 12c facing claws 12g are formed, via which the support of the holding element 12 in the bore 14 is improved. In the installed state of the holding element 12, the claws 12g thus engage in the inner wall of the flat part of the bore 14. There may also be two more claws at the lower end of the short leg 12a.

In the FIG. 8 is a plan view of the sheath body 2 of the fuse link 1 according to FIG. 6 shown. This figure is particularly clear the semi-circular cross-section of the bore 14 can be seen. Also, the recess 14c for the long leg 12b of the holding member 12 in the straight wall of the semicircular bore 14 can be seen.

The FIG. 9 shows a side view of a fuse link 1 for NH fuses in a third embodiment. This third embodiment is a modification of the second embodiment described above, which differs substantially in the manner of attachment of the spring element 11 to the indicator element 10. With respect to the other components, reference is made to the above description of the first and second embodiments. For attachment of the spring element 11 to the rod-shaped characteristic element 10, this has an obliquely downwardly directed pin 10b, which projects into the opening of the helical spring element 11. The spring element 11 is thus seen in the longitudinal direction of the bore 14 laterally next to the Kennmelderelement 10 and with respect to the sheath body 2 inwards staggered. The pin 10b also prevents that when mounted upper sealing and end plate 5o, 6o the characteristic element 10 in the display state "triggered" the hole 14 can leave.

Finally the shows FIG. 10 still a plan view of the jacket body 2 of the fuse link 1 according to FIG. 9 , It can be clearly seen that the lower part 14u of the bore 14 is offset with respect to the upper part 14o toward the web 2a, so that the inner walls of the upper part 14o and the lower part 14u facing the web 2a, with the exception of one possible Recess for the long leg 12b of the holding element 12c aligned with each other.

The FIG. 11 shows a side view of a fuse link 101 for NH fuses in another embodiment partially in section. The fuse link 101 consists essentially of a tubular shell body 102 made of steatite with a rectangular cross section, which defines a cavity 103 for a working conductor 104. The between the centrally disposed in the sheath body 102 working melt conductor 104 and the inner wall of the sheath body 102 remaining cavity 103 is filled with extinguishing sand.

The upper and lower ends of the shell body 102 are closed with an upper seal plate 105o and a lower seal plate 105u. The sealing plates 105o, 105u are made of an electrically insulating material, such as, for example, prespan or felt, and have a size that approximately matches the outer dimensions of the jacket body 102. Adjacent to the two sealing plates 105o, 105u are upper and lower end plates 106o, 106u which lie flat on the sealing plates 105o. 105u rest. The two end plates 106o, 106u are made of aluminum. According to the rectangular cross section of the sheath body 102, the flat seal plates 105o, 105u and the end plates 106o, 106u are also rectangular. The sealing plates 105o, 105u and the end plates 106o, 106u are fastened to the casing body 102 via screws 119, the stems of which are held in the casing body 102 in corresponding holes, not shown. Usually, four screws are provided per end plate 106o, 106u, which are respectively arranged in the corner regions of the end plates 106o, 106u. At the end plates 106o, 106u is in each case a contact blade 107o, 107u by caulking or Attached upsetting, which is electrically connected to the working flux conductor 104. The contact blades 107o, 107u have essentially the function releasably attach the fuse link 101 in resilient retaining clips of a fuse housing, not shown, and at the same time to connect electrically with the retaining clips can. In order to facilitate the handling of the fuse 101, the end plates 106o, 106u are extended beyond the shell body 102 to the front of the fuse link 101 and thus form grip tabs 108o, 108u, to which a handle, not shown, can be attached in the usual way.

Furthermore, the shows FIG. 11 in that associated with the working smelting conductor 104 is a display device 109, via which the state - "ready for operation" or "triggered" - can be read from the upper end side and the front side of the fuse link 101. The display device 109 essentially consists of a characteristic element 110, a spring element 111, a guide element 112 and a display melting conductor 113. On the basis of the identification element 110, an operator can visually recognize the state of the fuse link 101. In the FIG. 11 the indicator element 110 is shown in the display state "ready". The detail enlargement according to FIG. 13 shows the display status "triggered". The Kennmelderelement 110 is formed as a longitudinal strip of an aluminum band role and anodized red one or both sides over its entire length, so that it can be easily recognized by the operator. In addition, the indicator element 110 is formed angularly with a short leg 110a and a long leg 110b. The short leg 110a and the long leg 110b are preferably arranged at right angles to each other.

In order to be able to move the indicator element 110 in a defined manner between its two display states, the long leg 110b is guided in a guide groove 114. The FIG. 11 clearly shows that the guide groove 114 is arranged in the front side 2f of the sheath body 102 and is aligned parallel to the longitudinal direction of the sheath body 102. The guide groove 114 extends from the upper end side of the sheath body 102 to beyond the center thereof and has a total length of about 2/3 of the length of the sheath body 102. To form a channel for securely guiding the long leg 110b, the guide groove 114 is provided with a front panel 115 closed, which is approximately the entire front side 102f of the shell body 102nd covers. The front panel 115 is made of plastic and has approximately in the middle and thus in the region of the lower end of the guide groove 114, a viewing opening 116 for the operator. The front panel 115 is adhered to the front side 102f of the shell body 102. If the red identification element 110 or its red end region is seen in the viewing opening 116, the securing element 101 is ready for operation; if it is not seen, the long leg 110b of the indicator element 110 is displaced upward in the guide groove 114 and the fuse element 101 is triggered.

Further, this guide groove 114 is rectangular in cross-section and is formed starting from the upper end face 102o of the sheath body 102 in the direction of the lower end of a wedge-shaped tapered. In the region of the lower end, the height of the wedge-shaped guide groove 114 is slightly larger than the thickness of the characteristic element 114. Thus, it is ensured that the identification element 110 in the guide groove 114 can not rotate and is guided securely.

The indicator element 110 is with its long leg 110b from above through an opening 106a (see FIG. 3 ) inserted into the guide groove 114 and between the display positions "ready" and "triggered" in the longitudinal direction of the sheath body 102 slidably. So that the indicator element 110 or its long leg 110b can not leave the guide groove 114 in the "released" display state, a web-like projection 110c extending approximately at right angles to the longitudinal extent of the long leg 110b is provided on the side of the long leg 110b facing the jacket body 102b. In the display state "triggered", the indicator element 110 is supported with its projection 110c on the inside of the upper end plate 106o in the region of the opening 106a. Accordingly, the dimensions of an opening 106a provided in the upper end plate 106o for guiding the identification element 110 are adapted to the outer contour of the identification element 110; the projection 110c can not pass through the opening 6a. In addition, the projection 110c is designed to be of limited elasticity, so that when the long leg 110b of the indicator element 110 is mounted through the opening 106a in the upper end plate 106o, it will readily abut against the long leg 110b of the indicator element 110 and again after passing through the opening 106a jumps back and serves as a stop.

The purpose of the indicator fusible conductor 113 is to keep the indicator element 110 in the display state "ready for operation" against the voltage of the spring element 111, as long as the indicator fusible conductor 113 has not yet melted in response to the fuse link. For this purpose, the display melting conductor 113 is electrically connected in parallel to the working melt conductor 104. Accordingly, the ends of the display fusing conductor 113 are electrically connected to the upper and lower face plates 106o, 106u. The display fuse 113 is a wire made of nickel. The lower end 113u of the display fusion conductor 113 is led out through a sand hole 121 in the lower end plate 106u for filling the extinguishing sand into the shell body 102, and is pinched there by a sand plug 117 for closing the sand hole 121. The sand hole 121 is formed in a conventional manner as a circular bore which extends parallel to the longitudinal extent of the shell body 102. The sand plug 117 is made of brass or aluminum and dimensioned so that it is pressed from below into the sand hole 121 and held there by clamping.

Thus, the lower end 113u of the display fusion conductor 113 is connected to the lower end plate 106u. Starting from the sand stopper 117, the indicator melting conductor 113 extends through the cavity 103 of the sheath body 102 filled with extinguishing sand into the region of a further opening 118 (see FIG FIG. 13 ) in the upper face plate 106o. This opening 118 is disposed opposite to the sand hole 121 in the lower end plate 106u and closed with a guide member 112 for the display fusion conductor 113. In addition, this opening 118 is formed in a conventional manner as a circular bore which extends parallel to the longitudinal extent of the jacket body 102. The guide member 112 is formed as a sleeve-shaped plug with a circumferential collar or flange, which has a hole 112a for the implementation of the display melt conductor 113 centrally in its slightly conical bottom in the region of the outer tip. This guide element 112 is made of brass or aluminum and dimensioned so that it is pressed from above into the opening 118 and held there by clamping.

The guide element 112 serves in addition to the central guide of the display melt conductor 113 also a helical spring element 111th absorb, the lower end is supported on the bottom of the guide member 112 and loosely rests there. The upper end of the spring element 111 abuts against the underside of the short leg 110a of the indicator element 110 and is fastened there with its winding end via forms in the short leg 110a of the indicator element 110 on the short leg 110a of the indicator element 110. The spring element 111 is thus captively clamped between the short leg 110a of the characteristic element 110 and the guide element 112. About the spring element 111, the indicator element 110 from its display state "ready" in the display state "triggered" movable. For this purpose, the spring element 111 is biased during assembly of the Kennmelderelementes 110 and is in its biased state almost completely or completely within the guide member 112. In this biased state - display state "ready" - Kennmelderelement 110 and the spring element 111 against the force of the spring element 111 held over the corresponding biased display fuse 113. The upper end 113 o of the display fusion conductor 113 is connected in a clamping manner to the limb 110 a of the identification element 110 via forms.

The electrical contact between the upper end 113o of the display fuse 113 and the upper end plate 106o is made either directly via the contact of the display fuse 113 with the guide member 112 in the hole 112a or via its contact with the short leg 110a of the Kennmelderelementes 110, via the spring element 111 and the guide member 112 is electrically connected to the upper end plate 106o.

The FIG. 12 shows a front view of the fuse link 102 according to FIG. 11 with his contact knives 107o, 107u. Also suggestively seen from the sheath body 102 from outwardly open guide 114 for the long leg 110b dashed to recognize. Approximately in the middle of the front panel 116 - seen in the longitudinal direction of the sheath body 102 - the viewing opening for the indicator element 110 is arranged. In addition, the screws 119 for fastening the upper and lower end plate 106o, 106u can be seen on the end faces of the shell body 102.

In the FIG. 13 is an enlarged detail of the fuse element 101st to FIG. 11 from the area of the indicator element 110 shown. This view shows particularly clearly the operation of the indicator element 110. The indicator element 110 is shown in its display state "triggered", that is, the indicator fusible link 113 is melted through in parallel with the working flux conductor 104. The display fusible conductor 113 has - as previously described - the task to keep the indicator element 110 against the force of the spring element 111 in the display state "ready". For this purpose, the upper end 113o of the Kennmelderelementes 110 is attached to the underside of the short leg 110a of the Kennmelderelementes 110 and biases this against the force of the spring element 111 so that the underside of the short leg 110a of the Kennmelderelementes 110 on the flange of the guide member 112 and the Top of the upper end plate 106o rests. Since now the display melting conductor 113 has melted through, the spring element 111, which rests almost completely in the sleeve-shaped guide element 112 when it is pressed together, has relaxed. As a result, the indicator element 110 has been displaced so far upwards in the longitudinal direction of the jacket body 102 until the web-like projection 110c of the indicator element 110 comes to rest from below on the upper end plate 106o. In the display state "triggered" thus the short leg 110a is lifted from the upper end plate 106o, so that the front side of the triggering state of the fuse element 101 can be clearly recognized. Since now also the long leg 110b of the Kennmelderelementes 110 is displaced in the longitudinal direction of the shell body 102, the lower mostly colored end of the long leg 110b of the Kennmelderelementes 110 has left the lower portion of the guide channel 114 and thus the front view opening 116 released.

Furthermore, the shows FIG. 13 in that the opening 106a in the upper end plate 106o is of sufficient size to insert the long leg 110b of the indicator element 110, including the spring-back projection 110, into the guide channel 114 when the upper end plate 106o is mounted. The projection 110 can thus no longer slide in the display state "triggered" from the guide channel 114 upwards and thus serves as a stop. Advantageously, the spring element 112, the indicator element 110 and the display melting conductor 113 can be pre-assembled. After mounting the Kennmelderelementes 110, in particular the insertion of the long leg 110b of the indicator element 110 in the guide channel 114, the display fusion conductor 113 is threaded through the hole 112a in the bottom of the guide member 112, passed through the interior of the shell body 102 and led out the opposite sand hole 121. First, the display fusible conductor 113 is attached to the lower grip tab 108u so as to be clamped over the sand plug 117 after filling the shell body 102 with sand.

LIST OF REFERENCE NUMBERS

1

fuse link

2

covering body

2a

web

2 B

drilling

2f

front

2o

upper end side

2u

lower front side

3

cavity

4

Working fuse element

5a

opening

5o

upper sealing plate

5u

lower seal plate

6o

upper face plate

6u

lower face plate

7o

upper contact blade

7u

lower contact knife

8o

upper grip tab

8u

lower grip tab

9

display device

10

Characteristic detector element

10a

slot

10b

paragraph

10o

top end

11

spring element

12

retaining element

12a

short thigh

12b

long thigh

12c

opening

12d

opening

12e

flange

12f

pen

12g

claw

13

Indicating fuse element

13o

top end

13u

lower end

14

drilling

14a

paragraph

14b

opening

14o

upper part

14u

lower part

15

blind

16

second spring element

17

drilling

18

opening

19

contact element

20

Querkanal

21

Sandloch

101

fuse link

102

covering body

102f

front

103

cavity

104

Working fuse element

105o

upper sealing plate

105u

lower seal plate

106a

opening

106o

upper face plate

106u

lower face plate

107o

upper contact blade

107U

lower contact knife

108o

upper grip tab

108u

lower grip tab

109

display device

110

Characteristic detector element

110a

short thigh

110b

long thigh

110c

head Start

111

spring element

112

guide element

112a

hole

113

Indicating fuse element

end surface 113 o

top end

113u

lower end

114

guide

115

front panel

116

view port

117

sand plug

118

opening

119

screw

121

Sandloch

Claims (13)

1. Electrical fuse insert, in particular for a low-voltage high-power fuse, with an operative melting conductor (4) arranged in a tubular sleeve body (2) and with an indicator device (9) for indicating the operating states "ready-to-operate" and "released" of the fuse insert (1), consisting of an indicator melting conductor (13) connected electrically in parallel with the operative melting conductor (4) and consisting of an indicator element (10), connected to a spring element (11), for visually indicating the operating states, which in the operating state "ready-to-operate" is held by the indicator melting conductor (13) under tension of the spring element (11),
   characterized in that
   the indicator melting conductor (13) is attached to the tubular sleeve body (2) in a clamped manner with one end (13o) in the region of the indicator element (10) by means of a retaining element (12).
2. Electrical fuse insert according to Claim 1, characterized in that the indicator melting conductor (13) is wire-shaped and acts directly on the upper end (10o) of the indicator element (10).
3. Electrical fuse insert according to Claim 1 or 2, characterized in that the spring element (11) is implemented as a coiled spring.
4. Electrical fuse insert according to any one of Claims 1 to 3, characterized in that the indicator melting conductor (13) is guided over the upper end (13o) of the indicator element (10).
5. Electrical fuse insert according to any one of the preceding claims, characterized in that the spring element (11) is arranged in the wall of the tubular sleeve body (2).
6. Electrical fuse insert according to any one of the preceding claims, characterized in that the spring element (11) is supported in the tubular sleeve body (2) and attached to the indicator element (10) outside the ends (10o) of the indicator element (10).
7. Electrical fuse insert according to any one of the preceding claims, characterized in that the indicator element (10) is rod-shaped, displaceably arranged in a through-hole (14) of the sleeve body (2) between the operating states "ready-to-operate" and "released", and projects from the front face (2o) of the sleeve body (2) in the "released" operating state.
8. Electrical fuse insert according to any one of the preceding Claims 1 to 7, characterized in that the retaining element (12) is sleeve-shaped, the retaining element (12) is inserted into the opening of the through-hole (14), and the upper end (13o) of the indicator melting conductor (13) is clamped between the retaining element (12) and the through-hole (14).
9. Electrical fuse insert according to any one of the preceding Claims 1 to 7, characterized in that the retaining element (12) is implemented as a u-shaped bracket, which with one limb (12a, 12b) is inserted into the opening of the through-hole (14) and the upper end (13o) of the indicator melting conductor (13) is clamped between the retaining element (12) and the through-hole (14).
10. Electrical fuse insert according to any one of the preceding claims, characterized in that the spring element (11) is oriented with its direction of application of force parallel to the displacement direction of the indicator element (10).
11. Electrical fuse insert according to any one of the preceding claims, characterized in that the operating state of the fuse insert (1) can be indicated on the end face thereof and on the front thereof by the indicator device (9), in particular by the indicator element (10).
12. Electrical fuse insert according to any one of the preceding claims, characterized in that the indicator element (10) is implemented as a red anodized aluminium strip.
13. Electrical fuse insert according to any one of the preceding claims, characterized in that the other end (13u) of the indicator melting conductor (13) is attached to a second spring element (16).

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