FI112127B - Fuse cartridge - Google Patents

Description

112127

The fuse cartridge

The invention relates to a fuse cartridge according to the preamble of claim 1.

Fuse cartridges are used in modern switch fuses. Switch fuse means a combination of 5 load switches and a fuse base. In these modern switch fuses, the fuse is attached to a removable cartridge, a fuse cartridge, for safety reasons. The function of the fuse cartridge is thus to receive the fuse and act as a fuse protector as well as a positioning device which makes it easy to insert the fuse into the switch fuse. In addition, the fuses also participate in forming an electrical contact 10 between the fuse and the switch fuse.

A cassette-type switch fuse is generally designed so that the fuse cartridge can only be removed from the switch fuse body when the switch is open.

Therefore, the power must first be switched off by moving the switch fuse to the open position. The cartridges are then pulled out of the switch fuse without power to replace the fuse 15. The fuse itself is thus replaced safely completely outside the switchgear. This allows the work to be done under good lighting conditions and away from live parts. It is also possible to keep spare cartridges with an intact fuse pre-installed and get very fast • '. replace the fuse.

The present invention relates in particular to fuse cartridges for:

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1 * ', for substantially cylindrical fuses. In particular, the invention relates to fuse cartridges for fuses of the Neozed and Diazed type according to standard IEC60269-

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3-1. The invention also relates to fuse cartridges for other fuses which exist. . described in CEI / IEC 269-3-1. Of the fuses 1 · · * i ·, · · ·, 25 according to UL 198C, fuse types CC and J are suitable examples.

It is an object of the present invention to further improve the usability of the fuse cartridges: and to provide a fuse cartridge to which the fuse can be easily and reliably replaced without the use of tools.

The invention is based on providing a fuse cassette with a spring-loaded movable member 30, a carriage adapted to press the fuse in the fuse cassette operating position.

112127 2

Further, the fuse cassette is provided with locking means which allow the carriage to be locked in the retracted position while the fuse is being replaced. Once the new fuse has been inserted, the carriage can be released and the fuse cassette inserted into the switch fuse. In this position, the spring force ensures that sufficient contact pressure is created between the fuse and the fuse cartridge contact parts to form a good electrical contact.

More particularly, the fuse cartridge according to the invention is characterized in what is stated in the characterizing part of claim 1.

The invention provides considerable advantages.

In the fuse cartridge according to the invention, the fuse replacement is easy and can be done manually. Therefore, no separate tools are needed. In addition, the spring loading of the carriage ensures sufficient contact pressure.

The invention also has many inexpensive embodiments that can achieve significant additional advantages.

For example, the sled may be designed to travel along the track in the fuse cartridge so that the sled cannot fall unintentionally from its web. In this case, the fuse cartridge does not actually have any detachable fasteners and the possibility of loss of fasteners is eliminated. *: In some other solutions, the fuse may be attached with a bolt, for example, and the bolt may be lost when the fuse is replaced.

20 If the contacts connecting to the circuit outside the fuse cartridge are set to move with the carriage, the additional advantage is obtained that the opening of the open fuse cartridge: in the switch fuse is prevented.

. , The fuse cartridge also has an advantageous embodiment wherein the fuse cartridge includes a · · · bevelled surface adapted to receive 25 detectors detached from the blown fuse. In this embodiment, monitoring the condition of the fuse and detecting a fused * • * »* ♦ '' fuse is greatly facilitated. In a particularly preferred embodiment, the bevel surface of the fuse cartridge further includes a mirror-like portion, which in turn facilitates the detection of the detector pin. Further, the fuse cartridge may be designed so that the detector remains inside the cartridge until the fuse is replaced.

1121? / 3 This provides the advantage that the detector is not moved to places where it could cause interference.

The invention will now be described by way of example and with reference to the accompanying drawings.

Fig. 1 shows parts 5 of one of the fuse cassettes according to the invention removed from one another.

Figure 2 shows the fuse cartridge of Figure 1 as assembled and obliquely viewed from the front.

Figure 3 shows the replacement of the fuse in the fuse cartridge of Figure 1.

Fig. 1 shows a housing part 1 of a fuse cartridge, to which the other parts of the fuse cartridge 10 are connected and into which a fuse is fitted. The shell part is made of a material of suitable strength and an electrically insulating material, e.g., a suitable plastic. In Fig. 1, the front side of the fuse cartridge housing part 1 is face down and the rear part of the housing part is partially visible. In this case, the fuse cartridge front page refers to the page that remains on the fuse cartridge when the fuse cartridge is inserted into the switch fuse. The rear part, in turn, means the 15 parts that are at least partially retained within the clutch safety structure. Fig. 1 further shows a fixed contact 2 which is inserted into the housing part 1 in a recess made for this purpose. The fixed contact 2 is made of a suitable conductive material and is shaped with the contact tip 2a and the contact surface 2b. The contact tip 2a is intended to provide electrical contact with the contact parts ... · 20 of the switch fuse when the fuse cartridge is inserted in the switch fuse. The contact surface 2b '... ·, in turn, is intended to form an electrical contact with the fuse inserted in the fuse cassette. The contact 2 also has an opening * 2c for the purpose described below.

Fig. 1 also shows a movable part 3, which is referred to as a sled in this publication. • 25 The carriage can be made of electrically insulating plastic, like the cover part 1. In the carriage 3 ,, ..: a recess is formed in the front part for the other end of the fuse and a movable contact 4 is attached to the rear part so that the fuse pushed into the recess of the carriage 3 forms. contact with the contact surface 4b of the movable contact 4. Further, the movable contact includes a contact actuator 4a for making electrical contact with the contact portions of the switch fuse 30 when the fuse cartridge is inserted in the switch fuse.

4, 112127

Movement of the carriage 3 and the movable contact 4 means movement relative to the housing part 1 of the fuse cartridge. The mutual movement of the carriage 3 and the movable contact 4 is preferably prevented. For the relative movement of the carriage 3 and the shell member 1, the shell member 1 is formed with a web and suitable counter surfaces for the carriage 3 so that the carriage can move along the web 5 towards and away from the fixed contact 2. The track and mating surfaces are preferably designed to prevent the carriage 3 from accidentally leaving the track.

Figure 1 further shows a spring 5 which is fitted between the movable contact 4 and the wall of the housing part 1. In this position, the spring 5 pushes the carriage 3 toward the fixed contact 2 and thereby helps maintain the required contact pressure between the fuse and contact surfaces 2b and 4b when the cartridge is in the operating position. In other embodiments, the spring 5 may, of course, also be replaced by another spring-producing body.

Further, Figure 1 shows a mirrored plate 12 as well as a window 13 which, in a preferred embodiment of the fuse cartridge, is positioned at the bottom of the fuse cartridge as described in more detail below.

Figure 2 shows the front face of the fuse cartridge. An aperture is formed at the bottom edge of the shell part 1 into which the window 13 is fitted. The window 13 then prevents the finger, tool, conductor or the like from being inserted into the fuse cassette where it could come into contact with live parts causing a hazard. Behind the window, at the bottom edge of the shell portion 1, a bevelled surface 11 is formed which engages '' from the rear edge of the shell portion towards the front edge. Above the bevel surface 11 is a fixed contact 2, and in particular an opening 2c in the contact 2. Aperture 2c is positioned such that it is positioned at the fuse burn detector (part 10 in Fig. 3) so that when the fuse burns, the burn detector can fall through aperture 2c to a bevelled surface 25 where it is readily discernible. in an embodiment, a mirrored plate 12 is mounted over the bevel surface, · 12, so that the fuse burn indicator is visible over a very large area from the front of the cartridge through the mirror. «·; · 'Directly and as a mirror image It is also possible to see through the mirror that the fuse is ·' 30 in working order and a fire detector in place. A good and inexpensive mirror can be made of 1 ... · eg polyester.

112127 5

If desired, the fuse cassette can also be equipped with an electronic fuse condition indicator, for example.

Figure 3 shows a fuse cartridge in two different positions. The upper fuse cassette is illustrated in the operating position where it contains a fuse 6 and in which it can be inserted 5 into the switch fuse. The lower fuse cartridge is in the fuse change position. These two different positions are described in more detail below.

In the upper illustration, in which the fuse cartridge is in its operating position, the spring 5 pushes the fuse cartridge carriage 3 towards the fixed contacts, whereby the fuse 6 is pressed between the contact surfaces and a good electrical contact is formed between the two ends of the fuse. In this position, the position and mutual distance of the contact tips 2a and 4a also correspond to the position and mutual distance of the respective contact surfaces of the switch fuse, so that the fuse cartridge can be inserted into the switch fuse.

The figure further shows a hook 7 formed on the side surface of the carriage 3 and a corresponding hook 8 formed at the inner edge of the housing part of the fuse cartridge substantially at the hook 7.

The claws 7 and 8 are shaped and positioned such that, when the carriage 3 is pulled back, the claws 7 and 8 lock each other close to one end of the carriage 3 trajectory and hold the carriage 3 in this position against the load exerted by the spring 5. The function of the hooks 7 and 8 is thus to hold the gig 3 in the rear position while the fuse 6 is being replaced. In the lower picture, the fuse cassette is illustrated in this replacement position. Once the fuse has been replaced, · ;;; The carriage 3 releases the hooks 7 and 8, whereupon the spring 5 presses the carriage 3 forward again.

Release of the carriage 3 can be accomplished by either pushing the carriage 3 forward or by slightly pressing out the wall of the shell portion on which the hook 8 is formed. When doing this, the hooks 7 and 8 separate. Alternatively, the release of the staples 7 and 8 can also be effected e.g. ·. ; 25 around. This movement also releases the carriage 3.

...; A advantageous feature of the fuse cartridge shown in the figure and its replacement position is that: ': in the replacement position, the distance between the contact points 2a and 4a differs from: the corresponding distance in the fuse cartridge operating position. This is because. ': *. the movable contact contact tip 4a moves with the carriage 3 relative to the housing part 1 30 and the fixed contact 2. The deflected position of the contact guide 4a in the fuse 112127 6 exchange position prevents the fuse cartridge from being inserted into the switch fuse when the carriage 3 is not released.

The movement path of the fuse cartridge carriage 3 can even be designed so that the fuse in position prevents the carriage 3 from protruding 5 to the end point of its travel path. When this excess clearance is clearly greater than the tolerance of the switch fuse contact openings, the insertion of an empty fuse cartridge is prevented. This is because in an empty fuse cartridge the distance between the contact points 2a and 4a differs from the corresponding distance of the fuse cartridge. There is also the benefit of preventing the insertion of an empty cassette, as if an empty fuse cassette is inserted in its 10 positions, it may cause a malfunction if the system has a large number of fuses.

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Claims (10)

A fuse cassette, in which a fuse (6) can be arranged and comprising a shell portion (1) and contact means (2, 4) for coupling the fuse (5) (6) arranged in the fuse cassette to an electrical circuit outside the fuse cassette, characterized in that it comprises a sledge (3), power means (5) and reading means (7, 8) in such a way that the cage can be pulled against the power produced by the power means (5) in a retracted position and read in this position by means of the reading means (7, 8). ), and that the jaw (3) can be released from said retracted position and that the jaw (3) released together with the power means (5) is arranged to generate a contact pressure between the fuse (6) and the contact means (2,4). Device according to claim 1, characterized in that a web is formed in the shell portion (1) and the sled (3) is movably arranged along the web. 15 Fuse cartridge according to claim 1 or 2, characterized in that the contact means (2, 4) contain a stationary contact (2) which is fixed to the shell portion (1), and a movable contact (4) fixed to the the sledge (3) and which is arranged to rot in 'together with the sledge (3). »20 4. A fuse cartridge according to any one of claims 1-3, characterized in that the reading means (7, 8) contain a first hook (8) formed in the shell portion (1), and a second hook (7), which is formed in the sled (3), the first and second hooks (7, 8) being "II"; arranged to read each other as the sled is pulled in the retracted position. •; * 25 5. A fuse cartridge according to any one of claims 1-4, characterized in that: the collar member (5) contains a spring (5) arranged between the shell portion (1) and the sledge (3). • I> »* <t •« ιο 112127 6. A fuse cartridge according to any one of claims 1 to 5, characterized in that it comprises a faceted surface (11) arranged to receive an indicator button which is released from a well fuse (6). 5 Fuse cartridge according to claim 6, characterized in that mirror-like water (12) is connected to the beveled surface (11) to facilitate monitoring of the fuse condition. Fuse cartridge according to any one of claims 1-7, characterized in that the sled (3) contains a first recess for receiving one end of the fuse (6) and a second recess for connection to the power means (5) in such a way that the second recess the recess is located at the opposite end of the sledge relative to the first recess. 15 Fuse cartridge according to any of claims 1-8, characterized in that it is arranged to receive a fuse (6) having a first end having a first contact surface and a second end having a second contact surface, and which fuse (6). ) in its shape is substantially cylindrical in the region between the first and second ends. 20 10. A fuse cartridge according to any of claims 1-9, characterized in that the reading means (7, 8) are arranged to be released by manually coating the outer surface of the fuse cartridge. • · I