EP2390889A1 - Short-circuit device with fusible link provided with a fuse-holder and a fuse breaker with improved operating and handling safety - Google Patents

Abstract

The assembly has a fuse holder tube (21) pivotally mounted on a trunnion of a fuse-breaker. The fuse-breaker has a drive lever (3) pivoting on the trunnion in a direction opposite of a direction of pivoting of the tube, and a breaking lever (7) actuated by the drive lever. The mounting of the levers and the tube on the trunnion leaves sufficiently clear an area in the vicinity of an open lower end of the tube regardless of position of the levers and the tube in order to allow gases produced by breaking a fuse wire of a wire-fuse circuit-breaker to exhaust without disturbing flow of the gases. An independent claim is also included for a method for renovating a wire-fuse circuit-breaker.

Description

TECHNICAL AREA

The present invention relates to a fusible-wire type circuit breaker device, provided with a fuse holder and a fuse-holder device for mechanically severing the fuse in the form of a wire.

It relates more particularly to the relative mounting between the fuse and the fuse holder on the circuit breaker device.

A particularly interesting application of the device is its use as equipment of an overhead power distribution network typically from 7 kVolt to 38 kVolt (kV).

PRIOR ART

Fuse-type fuse-type circuit breakers are known comprising a fuse holder in which is housed an electric fuse in the form of a wire, and a device usually called a fuse-breaker for mechanically cutting the fuse wire.

A fuse-wire cut-out device 1 according to the state of the art is for example known from the patent. US 6,583,708 B1 .

Part of a fusible wire cut-out device 1 according to the state of the art is represented by simplified way on Figures 1 and 1A it comprises a fuse holder 2, a fuse breaking device with operating lever 3, a pin 4 on which the fuse holder 2 and the operating lever 3 are removable and pivotably mounted.

More specifically, fuse holder 2 comprises a base flange 20 at the bottom of tube 21 with extensions 200 pivoting with pin 4 through an axis 201.

Thus, the fuse holder 2 is pivotally mounted relative to the journal 4 via the axis 201. Its opening is carried out according to the arrow O of the Figure 1A by pulling effort on the eyelet 22.

The fuse-retaining device comprises an operating lever 3 whose hook-shaped end is adapted to be actuated by pulling an operator-supported maneuvering pole towards the ground when the cut-out device 1 is in position. installed configuration and in closed position to allow current flow.

The operating lever 3 comprises two arms 31, 32 and is removably and pivotably mounted on the journal 4 via a drive rod 6.

This driving rod 6 is mounted in the lugs 41 of the journal 4. The end of the two arms 31, 32 of the operating lever 3 in which the rod 6 is mounted with a tight fit is arranged in the interior space of the journal 4 delimited by the spacing between the two lugs 41 ( Figure 1A ).

Another lever 7 which forms the actual disconnecting lever comprises a cylindrical portion 70 within which the drive rod 6 is mounted with a tight fit. It also comprises a sectioning portion 71 adapted to be in contact with and stretching the fuse wire and a stop portion 72 adapted to come into mechanical abutment and exert a thrust force on the abutment portion 202 at the base 20.

The operating lever 3, the driving rod 6 and the disconnecting lever 7 are thus mounted integral in rotation around the geometric axis formed by the alignment of the two lugs 41.

The sectioning lever 7 is also in contact with a not shown return spring whose function is to prevent the lever 7 remains in the gas evacuation zone during the melting of the fuse wire. The spring also has the function of extracting the fuse wire from the tube during the breaking with weak currents.

The pin 4, meanwhile, comprises a threaded rod 40 on which a nut 5 can be screwed, the tubular portion 42 of the pivoting tube 2 fuse holder relative to the pin 4 through the axis 201 as explained above, and the lugs 41 of pivoting around a lower support portion of the device 1 not shown.

Thus, the pivot pins 41 constitute a pivot axis around the not shown support portion, the mechanical assembly constituted by the fuse holder tube 2, the device fuse holder comprising the operating lever 3, the pin 4, the driving rod 6, the disconnecting lever 7 and the return spring in position of the levers 3, 7 not shown.

The nut 5 serves to mechanically fasten the fuse wire which is also housed in the fuse holder tube 2 by allowing the passage of current between the two support portions (not shown) between which the fuse holder 2 is mounted in position. closure.

The operation of the device according to the state of the art 1 will now be explained only with reference to the manual operation of mechanical sectioning of the fuse wire when desired.

When an operator pulls (according to arrow A in figure 1 ) on the operating lever 3, it rotates thus the disconnecting lever 7 around the drive rod 6. This causes a cutting of the fuse wire also maintained around the thread 40 of the pin 4 by the nut 5, by the application of a stretching force by the portion 71 of the lever 7 which in contact with the wire comes to stretch and thus cut it.

The design of the circuit breaker according to the Figures 1 and 1A is further provided so that the end cap 23 of the tube 2 fuse holder 2 remains in contact with the upper part of the not shown support and thus not open before the complete cutting of the fuse wire. This mechanical opening of the tube 2 fuse holder after the complete cutting of the fuse wire is also provided by pivoting of the pin 4 relative to the support 200 through the axis 201 on the one hand and the pivoting of the same pin 4 relative to the lower jaw of the fuse holder by the This double rotation is only possible when the fuse wire no longer exerts tension between the pin 4 and the tube 2. This double rotation allows the lower part of the tube 2 to swing forward while descending (rotation about the axis 6 according to the arrow A which corresponds to the direction counterclockwise if we look at the fuse holder with the insulator implanted on the right and the tube 2 implanted on the left). By tilting, the tube 2 is no longer retained in its upper part by the spring blade shaped cap 23 and the entire tube completely rocked by gravity around the pin 4. This creates a disconnection distance between the upstream and downstream contacts and allows a visualization of the actual cut.

In addition, the abutment portion 72 of the severing lever 7 is adapted to abut against the abutment portion 202 at the base 20 of the fuse holder 2. This serves to keep all the parts in place in case of no breakage mechanical non-fusion of the fuse wire.

• sectionnement mécanique du fil fusible et donc coupure du courant entre la partie inférieure et supérieure du support,
• une fois la coupure de courant réalisée, pivotement du tube porte-fusible 2 depuis la partie inférieure du support par séparation entre la calotte d'extrémité 23 et la partie supérieure du support et donc ouverture du circuit électrique.

In other words, the design of a fuse-removing device is provided for carrying out, during the operation of the lever 3, the following sequence:

• mechanical sectioning of the fuse wire and thus breaking of the current between the lower and upper part of the support,
• once the power failure is achieved, pivoting of the fuse holder tube 2 from the lower part of the support by separation between the end cap 23 and the upper part of the support and thus opening of the electrical circuit.

The inventors have found that a major risk remains in all devices of this type currently marketed.

This major risk is that when the operator actuates the operating lever 3 (according to the arrow A in figure 1 ), it can occur an opening fuse holder 2 of its support while it is still under electric load (wire not yet mechanically cut).

It is easily understood that such an opening reaction is not the desired maneuver and that it causes security problems for the operator. In addition, this can cause damage to the high and medium voltage lines on which a circuit breaker is installed.

In addition, the device of the state of the art as represented on the Figures 1 and 1A has the following disadvantages. By construction, as explained above, the arms 31, 32 of the operating lever 3 have their end arranged in the interior space of the pin 4 defined by the two lugs 41 and extend below the fuse holder tube 2.

To avoid any mechanical interference between the operating lever 3 and the fuse tube 2 below when actuating said lever, it is necessary to provide a significant clearance between them. This involves making a lever 3 with a spacing between arms 31, 32 accordingly. In other words, the operating lever 3 is complex in shape and therefore complicated to achieve and it still constitutes an obstacle to the evacuation of gases.

It can be considered that a solution to the problem of undesirable opening of the fuse holder of its support while it is still under electric load has already been proposed in the document US 4,774,488 Indeed, the opening of the fuse holder 7 is in the clockwise direction and the actuation of the operating lever 30 of the fuse wire 12 is made in the counterclockwise direction. Although the document itself states that actuation of the operating lever 30 does not induce force on the other elements of the device (see column 4, lines 23-27), this statement is to be weighted. Indeed, the pivot axis 33 of the operating lever 30 is fixed on the mounting base 19 of the fuse holder 7, somehow cantilever and is distinct from the pivot axis 26 of the assembly mechanical consisting of the fuse holder 7, 8 with its base 19 and the fuse holder device comprising the operating lever 35, the pin 21, 27 and the actual cutting lever 25.

Thus, the actuation of the operating lever 30 can still induce unwanted stresses desired on the fuse holder 7, 8 and which can go up to open it.

In addition, the device according to this document has another major disadvantage: as illustrated in FIG. figure 3 , some of the parts of the fuse holder for breaking the fuse wire are arranged on one side of the mounting base 19 of the fuse holder tube 8, while other of these parts are arranged on the other side of the base 19. More specifically, the disconnecting lever 25 for breaking the fuse is pivotally mounted on one side of the base 19 while the operating lever 30 whose end 34 connecting the arms 31, 32 operates. the pivoting of the disconnecting lever 25 is mounted on the other side. This arrangement therefore involves having the arms 31, 32 of the operating lever 30 below the tube 8. However, when the current is cut off, a correct exhaust of the blowing gases emitted is decisive for the smooth running of this break. Thus, the presence of any element on the exhaust path creates turbulence that can raise the plasma area above the tube which can cause a breakdown outside the tube between the downstream contact (located above) and the support of the circuit breaker. Consequently, the presence of the arms 31, 32 of the lever 3 below the tube is unacceptable for the smooth running of the power cut, particularly when the cut is not initiated by the mechanical sectioning caused by the fuse-protection device, because they can disturb the escape of the blowing gases, which can be translated either by effective non-cutting of the fuse wire, or by a rise of the conductive gas zone (plasma) around the tube and therefore lead to a priming outside the tube 8 fuse holder.

• tout risque de réaction d'ouverture du porte-fusible sous charge électrique lorsque le levier de manoeuvre est actionné afin de sectionner mécaniquement le fil fusible,
• tout risque de perturbation d'échappement des gaz de soufflage avec remontée dans le tube porte-fusible.

The object of the invention is therefore to propose a solution for a fuse-wire cut-out device which overcomes the disadvantages of the devices of the prior art and more particularly which makes it possible to avoid at the same time:

• any risk of opening reaction of the fuse holder under electric load when the operating lever is actuated to mechanically cut the fuse wire,
• any risk of exhaust gas discharge disturbance with recovery in the fuse holder tube.

Another object of the invention is to provide a simple solution to achieve and easy to assemble.

Yet another object of the invention is to propose a solution that can be implemented on at least a part of an already existing circuit breaker, particularly that comprising the frame with the insulator, such as an insulator. porcelain.

STATEMENT OF THE INVENTION

• un tube porte-fusible adapté pour loger un fil fusible, dont l'extrémité supérieure comprend une calotte adaptée pour fermer le tube, permettre l'insertion d'une extrémité du fil fusible et la maintenir en place et l'extrémité inférieure est ouverte pour laisser s'échapper les gaz issus d'une coupure du fil fusible, le tube porte-fusible étant adapté pour être monté à pivotement entre une position d'ouverture dans laquelle il est seulement en contact avec la partie inférieure du support et une position de fermeture dans laquelle il est également en contact et en butée avec la partie supérieure de support ;
• un dispositif casse-fusible comprenant :
  • ■ un tourillon sur lequel est monté à pivotement le tube porte-fusible, comprenant des ergots adaptés pour être montés de manière amovible sur la partie inférieure du support pour permettre le pivotement de l'assemblage mécanique par rapport à cette dernière, et des moyens de fixation de l'autre extrémité du fil fusible,
  • ■ un levier de manoeuvre monté à pivotement sur le tourillon et adapté pour être actionné par un opérateur,
  • ■ un levier de sectionnement monté à pivotement par rapport au tourillon et adapté pour être actionné par le levier de manoeuvre et étirer mécaniquement le fil-fusible pour le sectionner,

assemblage dans lequel le sens de pivotement du levier de manoeuvre sur le tourillon est opposé à celui pivotement du tube porte-fusible et dans lequel le montage des leviers et tube porte-fusible sur le tourillon laisse suffisamment dégagée la zone à proximité de l'extrémité inférieure ouverte du tube quelle que soit la position des leviers et du tube afin de laisser s'échapper les gaz issus d'une coupure du fil fusible sans perturber leur écoulement.These objects are achieved by a mechanical assembly for a fusible wire cut-out device, the assembly being adapted to be removably mounted and pivoted between two parts of a cut-out device holder, comprising:

• a fuse-holder tube adapted to house a fuse wire, whose upper end comprises a cap adapted to close the tube, to allow insertion of an end of the fuse wire and hold it in place and the lower end is open to let out the gases from a cutoff of the fuse wire, the fuse tube being adapted to be pivotally mounted between an open position in which it is only in contact with the lower part of the support and a position of closure in which it is also in contact and abutting with the upper support part;
• a fuse device comprising:
  • A trunnion on which is pivotally mounted the fuse holder tube, comprising lugs adapted to be removably mounted on the lower part of the support to allow the pivoting of the mechanical assembly relative to the latter, and means for fixing the other end of the fuse wire,
  • An operating lever pivotally mounted on the trunnion and adapted to be actuated by an operator,
  • ■ a cutting lever pivotally mounted relative to the journal and adapted to be actuated by the operating lever and mechanically stretching the fuse-wire to cut it,

assembly in which the pivoting direction of the operating lever on the trunnion is opposed to that pivoting of the fuse holder tube and wherein the mounting of the levers and fuse holder tube on the journal leaves sufficiently clear the area near the open bottom end of the tube regardless of the position of the levers and the tube to let out the gases from a cut fuse wire without disturbing their flow.

The invention therefore consists essentially in making a relative mounting between the fuse holder and the fuse-breaker which is the reverse of that currently performed on the existing circuit breaker devices and which does not interfere with the evacuation of the gases necessary for blowing. the arc when cutting the fuse wire. Thus, the mechanical actuation of the operating lever according to the invention induces mechanical forces to the opposite of those necessary for opening the fuse holder and no part comes to impede the area below the fuse holder tube necessary for the exhaust gas during a power failure.

In other words, during the operation by the operator of the operating lever and until the fuse wire is cut, the induced mechanical forces always contribute to maintaining the fuse holder between the two conductive parts of the support. This mechanically and simply secures the inadvertent risk of opening under electric load of the fuse holder.

According to an advantageous characteristic, the operating lever is of elongate straight shape with an arm arranged laterally with respect to the journal and at a distance from the fuse holder tube. So the lever of maneuver is simple to carry out and its layout also.

Preferably, the operating lever actuates the disconnecting lever by a drive shaft integral with the operating lever and mounted in the pivot pins of the journal. Thus, one defines in a way a common axis of actuation of the fuse breaking device and the pivoting of the pin and therefore the fuse holder tube in its support. In other words, a direct mechanical interference is made between the support of the assembly and the fuse-holder during the pivoting of the fuse holder.

Preferably, the drive shaft is screwed onto the operating lever.

Advantageously, a cam is mounted with a tight fit on the drive shaft and bears against the severing lever, the cam further comprising a stop portion adapted to abut against a stop portion of the fuse holder tube and cause it to pivot once the fusible wire has been cut. Thus, by operating the operating lever, it exerts a moment of force directly on the disconnecting lever through the cam, and thus reduces the mechanical forces to be applied compared to the solutions according to the state of the art.

According to one embodiment, there is provided a shaped part to abut against the trunnion and on which is pivotally mounted the disconnecting lever, said part being integral with the trunnion by the drive shaft passing therethrough. This variant may be advantageous in configurations where an existing cut-out device is renovated with only an existing trunnion hole.

Alternatively, in another mode, the disconnecting lever is pivotally mounted on the trunnion. This mode is advantageous because fewer parts are used since the pivoting of the sectioning lever is done directly on the trunnion.

Preferably, the drive shaft is also the pivot axis of the journal.

1. a) démontage d'un assemblage mécanique comprenant le tube porte-fusible, un dispositif casse-fusible comprenant un levier de manoeuvre adapté pour être actionné par un opérateur et un levier de sectionnement d'un fil fusible actionné par le levier de manoeuvre, dans lequel l'actionnement du levier de manoeuvre engendre des forces mécaniques selon le sens de pivotement du porte-fusible vers sa position d'ouverture dans son support ;
2. b) remontage d'un assemblage mécanique tel que décrit précédemment.

The invention relates to a method for renovating a fuse-wire cut-out device comprising a fuse-holder tube and a fuse-breaking device, according to which the following steps are carried out:

1. a) disassembly of a mechanical assembly comprising the fuse holder tube, a fuse-eliminating device comprising an actuating lever adapted to be actuated by an operator and a disconnecting lever of a fuse wire actuated by the operating lever, in which actuation of the operating lever generates mechanical forces in the direction of pivoting of the fuse holder to its open position in its support;
2. b) reassembly of a mechanical assembly as described above.

Thus, the method according to the invention makes it possible to somehow achieve interchangeability of a portion of the circuit breaker devices to secure existing ones for mechanical maneuvers. fuse breakage, without any impact on the overall performance of the equipment.

According to one embodiment, when the mechanical assembly according to step a) comprises a journal on which are pivotally mounted the operating levers and sectioning and the fuse holder tube, prior to step b) is carried out a step a1) of modifying the journal and the mechanical assembly is raised with the modified journal according to step a1).

Step a1) may advantageously consist of a piercing of the trunnion.

Finally, the invention relates to the use of a fuse-wire cut-out device comprising a mechanical assembly previously described as an equipment for an overhead electrical distribution network, typically from 7 kV to 38 kV.

Advantageously, the operating lever is in substantially horizontal position when the circuit breaker device is in the installed configuration and in the closed position.

Advantageously, the lever is arranged on the right side of the fuse holder relative to an operator below the cut-out device in the installed configuration and in the closed position.

Preferably, the actuation of the lever by an operator is a pulling force towards the ground.

BRIEF DESCRIPTION OF THE DRAWINGS

• la figure 1 est une vue en perspective isométrique d'un assemblage mécanique d'un dispositif coupe-circuit à fil fusible selon l'état de l'art,
• la figure 1A est une vue en perspective isométrique éclatée d'un assemblage mécanique du dispositif selon la figure 1,
• la figure 2 est une vue en perspective isométrique d'un assemblage mécanique d'un dispositif coupe-circuit à fil fusible selon un premier mode de l'invention,
• la figure 2A est une vue en perspective isométrique éclatée du dispositif selon la figure 2 ;
• les figures 3 et 4 sont des vues en perspective isométrique selon différents angles d'un assemblage mécanique d'un dispositif coupe-circuit à fil fusible selon un deuxième mode de l'invention,
• les figure 5A et 5B sont des vues en perspective isométrique d'une partie d'un assemblage mécanique d'un dispositif coupe-circuit à fil fusible selon l'invention,
• les figures 6A et 6B sont des vues de face et de côté du dispositif selon le deuxième mode de l'invention,
• la figure 7 est une vue en perspective isométrique d'un dispositif coupe-circuit selon l'invention en configuration installée.

The invention will be better understood on reading the following detailed description. made, by way of illustration and not limitation, by reference to Figures 1 to 7 among :

• the figure 1 is an isometric perspective view of a mechanical assembly of a fuse-wire cut-out device according to the state of the art,
• the Figure 1A is an exploded isometric perspective view of a mechanical assembly of the device according to the figure 1 ,
• the figure 2 is an isometric perspective view of a mechanical assembly of a fuse-wire cut-out device according to a first embodiment of the invention,
• the Figure 2A is an exploded isometric perspective view of the device according to the figure 2 ;
• the Figures 3 and 4 are isometric perspective views at different angles of a mechanical assembly of a fuse-wire cut-out device according to a second embodiment of the invention,
• the Figure 5A and 5B are isometric perspective views of a portion of a mechanical assembly of a fusible wire cut-out device according to the invention,
• the Figures 6A and 6B are front and side views of the device according to the second embodiment of the invention,
• the figure 7 is an isometric perspective view of a circuit breaker device according to the invention in installed configuration.

DETAILED PRESENTATION OF PARTICULAR EMBODIMENTS

Only the mechanical parts of fuse cut-out devices according to the state of the art and according to the invention which serve to illustrate the operation of the invention are described precisely.

Thus, the fuse wire, the support of the fuse holder, the insulator part and the conductive terminals which are shown in FIG. figure 7 .

For more understanding, we can refer to all the technical documentation, and for example to the patent US 6,583,708 B1 , which describe all the parts and functions of a fuse cut-off device used as a high-voltage overhead network equipment.

For the sake of clarity, the parts common to the cut-out device according to the state of the art ( Figures 1 and 1A ) and according to the invention ( Figures 2 to 7 ) bear the same references.

Throughout the present application, the terms "lower" and "upper" are to be considered by reference to the circuit breaker device according to the invention in configuration installed in its support, the operating lever to be actuated by pulling towards the bottom by an operator and the fuse holder tube being intended to pivot also downwards.

The Figures 1 and 1A of the circuit breaker device according to the state of the art have already been commented on in the preamble, so they are not commented on here.

The inventors have found that there is a major risk when operating the operating lever 3 of a device according to the state of the art shown in FIGS. Figures 1 and 1A . Indeed, the forces or forces according to the arrow A may cause a reaction of the pin 4 and thereby the fuse holder 2 according to the arrow R of the figure 1 , that is to say in the same direction O opening fuse holder 2. However, during this actuation and before mechanical sectioning of the fuse wire, the electric current passes. In other words, the fuse holder is still under load and its opening can cause adverse consequences on the operator.

In addition, in a circuit breaker according to the state of the art as described in the patent US 4, 774, 488 , the mounting of the operating lever 30 and the disconnecting lever 25 is such that they are arranged below the fuse holder tube. They thus hinder the escape of gas from the cutting of the arc caused by cutting the fuse wire.

Therefore, the inventors have made a mechanical assembly according to the Figures 2 to 6B in which the mechanical actuation of the operating lever 3 does not cause a reaction force on the journal 4 and the fuse holder 2 in the opening direction O and in which no mechanical part obstructs the evacuation of the gases from the cutting of the arc caused by cutting the fuse wire.

In other words, the mechanical assembly according to the invention induces mechanical forces as opposed to those necessary for the opening of the fuse holder tube.

As in Figures 1 and 1A , the fuse holder tube 2 comprises an end cap 23 adapted to close the tube, allow the insertion of an end of the fuse wire and hold it in place and the pin 4 comprises a threaded rod 40 on which is screwed a nut 5 and thus constituting the fastening means of the other end of the fuse wire.

The circuit breaker device 1 according to the invention further comprises the device according to the state of the art, a cam 8 mounted with a tight fit around a drive shaft 6 itself attached to the operating lever 3 by a screw 12.

In the embodiment of Figures 2, 2A and 5A , the sectioning lever 7 is pivotally mounted on an additional piece 9 has a surface 9.1 which fits an inner surface 410 of the pin 4. This locking piece 9 further comprises holes 90 through which the drive shaft 6 past.

Furthermore, the mounting of the sectioning lever 7 is provided with a return to the additional part 9 by means of a return spring 11 mounted around a rod 10 itself mounted in the part 9. This spring recall 11 thus allows the return in position of the sectioning levers 7 and maneuver 3 when no effort is applied to the latter.

A pivoting of the drive shaft 6 by actuating the operating lever 3 causes a pivoting of the sectioning lever 7 via the cam 8 but not pivoting of the part 9.

In the embodiment according to Figures 3, 4 , 6A and 6B , the disconnecting lever 7 is pivotally mounted on the journal 4 via the rod 10 around which the return spring 11 is mounted.

As better visible in Figure 5A , the assembly provided according to the invention makes it possible to exert a moment of force on the severing lever 7 directly with the aid of the operating lever 3 via the cam 8.

In addition, a stop portion (80 on the Figure 5A and 72 on the Figure 5B ) on the lever 7 allows in cooperation with a stop portion 202 at the bottom of the tube to maintain said lever 7 in its initial position and against the force exerted by the return spring and without exerting effort on the fuse wire.

As better visible in Figure 5B it is possible to mount the drive shaft 6 on a tubular portion 70 of the sectioning lever 7.

As better visible in Figures 6A and 6B the operating lever 3 is elongate in shape with an arm arranged laterally with respect to the journal 4 and at a distance from the fuse holder tube 21.

In the embodiment of Figures 2, 2A and 5A when actuating the operating lever 3 according to the arrow A, the cam 8 is rotated and causes the lever to pivot downwards. sectioning 7 by pivoting on the part 9. The pivoting of the sectioning lever 7 in contact with the fuse wire will stretch the latter until it is cut. The part 9 bearing against the inside 410 of the pin 4 is not displaced and therefore does not cause a reaction of the pin 4 and the fuse holder 2 according to the arrow O opening of the latter.

For the embodiment of Figures 3, 4 and 6A, 6B , in which the pivoting of the cam 8 by the operating lever 3 causes the disconnecting lever 7 in the same direction A always opposed to that of pivoting of the tube 21 fuse holder 2.

The non-obstruction of the gases resulting from the cutting of the arc caused by the cutting of the fuse wire is highlighted in figure 4 , where it is seen that no part, and in particular the sectioning lever 7 is opposite the opening 210 of the tube 21 fuse holder 2.

In figure 7 , there is shown a fusible wire cut-out device comprising a mechanical assembly according to the invention and used as equipment of an overhead electrical distribution network, typically from 7 kV to 38 kV. This equipment essentially comprises as usual an insulator 13 and a two-part support 140, 141.

The mechanical assembly according to the invention is removably mounted between the two parts 140, 141 of the support, the lugs 41 of the journal 4 or the drive shaft 6 being wedged in the lower part 140 of the support while the cap end 23 is in the closed position of the tube 21 fuse holder 2 set in the upper part 141 of the support.

Other improvements and variations can be made to the mechanical assembly described without departing from the scope of the invention.

Thus, for example, if the operating levers 3 described are actuated by a maneuver of an operator in the counterclockwise direction by looking at the cut-out device from the front with the insulator on the right ( figure 7 ), a maneuver in the clockwise direction by looking at the device in a similar way can be considered.

One can also consider a maneuvering lever shaped to be actuated by the operator by pushing force upwards.

Claims (13)

Mechanical assembly for a fusible-wire cut-out device (1), the assembly being adapted to be removably and pivotally mounted between two portions (140, 141) of a cut-off device holder (14), comprising: - A fuse holder tube (2) adapted to house a fuse wire, the upper end comprises a cap adapted to close the tube, allow the insertion of an end of the fuse wire and hold it in place and the end bottom is opened to let out gases from a cutoff of the fuse wire, the fuse holder tube being adapted to be pivotally mounted between an open position in which it is only in contact with the lower part of the support and a closing position in which it is also in contact and abutting with the upper support part, a fuse-eliminating device comprising: A journal (4) on which is pivotally mounted the tube (2) fuse holder, comprising pins adapted to be removably mounted on the lower part of the support to allow pivoting the mechanical assembly relative to the latter , and means for fixing the other end of the fusible wire, An operating lever (3) pivotally mounted on the trunnion (4) and adapted to be actuated by an operator, ■ a cutting lever pivotally mounted relative to the journal and adapted to be actuated by the operating lever and mechanically stretching the fuse-wire to cut it, assembly in which the pivoting direction of the operating lever on the trunnion is opposite that of the pivoting of the fuse holder tube and in which the mounting of the levers and fuse holder tube on the trunnion sufficiently clear the area near the end open bottom of the tube regardless of the position of the levers and the tube to allow escape gases from a cut fuse wire without disturbing their flow. Mechanical assembly according to claim 1, wherein the operating lever is of elongated straight form with an arm arranged laterally with respect to the journal (4) and at a distance from the fuse holder tube. Mechanical assembly according to claim 1 or 2, wherein the actuation of the disconnecting lever by the operating lever is formed by a drive shaft (6) integral with the operating lever and mounted in the lugs of the journal. Mechanical assembly according to claim 3, wherein the drive shaft is screwed onto the operating lever. Mechanical assembly according to claim 3 or 4, wherein a cam is mounted with a tight fit on the drive shaft and bears against the disconnecting lever. Mechanical assembly according to one of claims 3 to 5, wherein the disconnecting lever is pivotally mounted on the journal (4). Mechanical assembly according to claim 6, wherein the drive shaft (6) also constitutes the pivot axis of the journal (4). A method of refurbishing a fuse-wire cut-out device comprising a fuse holder tube and a fuse-breaker device, according to which the following steps are carried out: a) disassembly of a mechanical assembly comprising the fuse holder tube, a fuse-eliminating device comprising an actuating lever adapted to be actuated by an operator and a disconnecting lever of a fuse wire actuated by the operating lever, in which actuation of the operating lever generates mechanical forces in the direction of pivoting of the fuse holder to its open position in its support; b) reassembly of a mechanical assembly according to one of the preceding claims. Renovation method according to claim 8, wherein the mechanical assembly according to step a) comprises a journal on which are pivotally mounted the operating and disconnecting levers and the fuse holder tube, prior to step b a step a1) for modifying the journal is carried out and the mechanical assembly is raised with the journal modified according to step a1). Renovation method according to claim 9, wherein step a1) consists of a piercing of the trunnion. Use of a fusible wire cut-out device comprising a mechanical assembly according to any one of claims 1 to 7 as an equipment of an overhead electrical distribution network, typically from 7 kV to 38 kV. Use according to claim 11, wherein the operating lever is in substantially horizontal position when the circuit breaker device is in the installed configuration and in the closed position. Use according to claim 11 or 12, wherein the operating lever is arranged on the right side of the fuse tube relative to an operator below the circuit breaker in the installed configuration and in the closed position.

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