US3518599A - Box for cartridge fuses with fuse ejector - Google Patents

Description

June 30, 1970 c. P. LANUX BOX FOR CARTRIDGE FUSES WITH-FUSE EJECTOR Filed Jan. 50, 1969 2 Sheets-Sheet l June 30, 1970 c. P. LANUX 3,513,599

BOX FOR CARTRIDGE FUSES WITH FUSE EJ ECTOR Filed Jan. 30, 1969 2 Sheets-Sheet 3 nited States Patent 38,661 Int. Cl. H0111 85/00, 85/02, 85/22 US. Cl. 337-186 6 Claims ABSTRACT OF THE DISCLOSURE An improved fuse box for cartridge fuses is provided with an ejector lever which is fitted to the face of the fuse box at a point between the fuse contact clips and is arranged to fit within the fuse cavity in the box while taking up any minimum of additional space. The lever is arranged so that upward movement of the free end of the lever causes corresponding upward pivoting movement of the fuse.

The present invention relates to a fuse box provided with means for the extraction of spent cartridges.

It is known for fuse boxes made from insulating material to be formed with individual spaces, each separated from neighbouring spaces by a partition, for receiving the cartridges. In each of these spaces are arranged terminals with jaws which accommodate the two ends of the cartridge. With a view to reducing the bulk of electrical apparatus, these insulating boxes are made as small as possible, so that the spaces in which the cartridges are accomanodated are of a size limited almost to that of the fusesupporting jaws. When the cartridge is inserted between the jaws, only little space is left on either side between the jaw and the partition, so that it becomes very difficult to extract the cartridge when it has to be replaced because of a short-circuit.

It has already been suggested (for example, in US. Pats. 2,004,327, 2,004,328, 2,009,235, 2,984,723) to use, for the purpose of extracting a fuse cartridge from its working position, a manually actuatable lever, hinged below the cartridge when the latter is in position, and comprising a transverse portion by which the cartridge is moved from below, near one of its ends, in such a way that it is moved away from the bottom of the box and made to pivot about the contact element co-operating with the other end of the fuse.

In known constructions of this kind, the lever is provided either in prolongation, or laterally, of the cartridge and, in order to effect extraction, this lever pivots in opposition to the pivoting movement of the cartridge. Therefore, these known devices require, for the normal accommodation of the lever as well as for its operating movement, a space far greater than that allotted to the cartridge.

The present invention has for its objects a lever mechanism enabling a fuse cartridge to be extracted which, for its setting up as well as its operation, requires almost no additional space, so that the minimum dimensions of fuse boxes can be adhered to.

The present invention provides an improved fuse box for a cartridge fuse, of the kind wherein a cartridge fuse is held between a pair of terminal clips and a manually actuatable fuse ejector lever is mounted in the box by a pivot axis located below the lever of the fuse for pivotal movement to cause rotation of said cartridge fuse ejector about one of said terminal clips thereby disengaging said fuse from the second of said terminal clips, wherein said improvement consists in the location of said pivot axis at a point intermediate said terminal clips, and the use of a Patented June 30, 1970 lever formed with a transversed fuse-engaging member at a point between said pivot axis and the free end of said lever, said member normally underlying said fuse adjacent one of said terminal clips. Advantageously, said lever comprises a stirrup-like member of flat, strip-like material with first and second limbs straddling said fuse and pivotally mounted at their free ends, said lever having an intermediate transverse strut bridging said limbs to constitute said fuse-engaging member.

Thus when the lever is raised by hand, the cartridge follows its pivoting movement. Moreover, the lever moves only within the space associated with each cartridge chamber and, on the surface, occupies hardly more space than the cartridge.

It will be noted that a cartridge extraction lever pivoting in the same sense as the fuse during extraction is already known (American Pat. 2,421,982). According to this specification, however, the lever is longer than the cartridge. It covers the latter, and its pivoting axis is situated beyond the resilient cartridge-holding element which also forms a pivot for the cartridge, whereas, at its other end, it engages the corresponding cartridge and by means of a collar. A device of this kind is complicated, bulky and expensive.

In order to facilitate the cooperation of lever and cartridge the first transverse portion, where it faces the cartridge, may bbe provided with a rounded surface and is preferably an element consisting of a curved plate.

The invention applies to the usual type of cartridge, with end portions of expanded diameter and symmetrical shape, but also to fuses having one end tapered in which the contact surfaces are constituted by the end faces.

In this case the contacting device receiving the tapered end is the one which permits the pivoting movement of the cartridge and this contacting device comprises a conductive pivotable support influenced by the force of a resilient member acting in the direction towards the other contacting element, an insulating sheath, which is hinged on the first support, receiving the tapered end of the cartridge.

Moreover, the pivot about which the sheath rotates and the pivot of the hinged support arep referably situated on opposite sides of the sheath axis, this arrangement facilitating the pivoting of the cartridge.

The following description, given with reference to the accompanying drawings by way of a non-limiting example, will help to understand how the invention can be put into practical effect, but it should be well understood that any features becoming apparent from the drawings or the text must be considered to form part of the said invention.

FIG. 1 is a plan view of a fuse box.

FIG. 2 is a sectional view along the line IIII of FIG. 1.

FIG. 3 is a view similar to that of FIG. 2, with the extraction lever in the upward position.

FIG. 4 is a sectional view along the line IV-IV of FIG. 2.

FIG. 5 shows, in a sectional view, similar to that of FIG. 2, a modification for fuse cartridges the end faces of which are conductive.

FIG. 6 is a view similar to that of FIG. 5, showing the extraction lever in the upward position.

FIG. 7 is a view similar to that of FIG. 5, showing a modified embodiment.

FIG. 8 is a perspective view of an extraction lever in the shape of a stirrup.

The box A shown in FIG. 1 comprises three fuse cartridges 1 of the usual type, i.e., cylindrical and with conductive end portions. These end portions are each held by clip terminals 2 and 3 respectively, an arrangement well known per se.

Current reaches the clip 2 through an extension lug 4 of this clip terminal; it reaches the clip terminal 3 either through the fixing screw 5 or through one of the separate lugs 6 or 7. To make this possible, the latter comprises a locking screw 8. The separate lug 7 is provided with flanges 9 traversed by a hinge 10 which enables the lever 11 to pivot.

As becomes apparent from FIG. 8, the lever is pro vided in the form of a stirrup and comprises between its side portions, a curved portion 12 which, in the normal position of the cartridge (FIG. 2), is situated under the end portion of this cartridge which is held by the clip terminal 3.

Through the hinge 10 the lever 11 is at the same potential as the clip terminal. Therefore, it does not matter if, in the normal position, the transverse portion 13, which enables actuation of the lever by hand, is closely adjacent the cartridge end.

It will be understood, according to FIG. 1, that it is almost impossible ot extract a cartridge from its working position by using the fingers. As will be seen in FIG. 3, it is possible, by gripping the portion 13 of the lever and making it pivot in the direction towards the clip terminal 2, to cause the cartridge 1 to pivot in the same sense whereby the cartridge becomes accessible to being gripped by hand.

Obviously, it is assumed that the operation of inserting a fuse takes place in a circuit to which supply voltage is not applied. This is the case when a box such as shown in FIG. 1 is integrally constructed in a removable connector and, for the purpose of changing fuses, the connector is withdrawn from the live conductive parts with which it is cooperable.

When a spent cartridge has been extracted, and the lever 11 lowered to the position shown in FIG. 2, a new cartridge can be positioned in the usual manner by being inserted between the clip terminals 2 and 3.

The device describedhere is also applicable to cartridges in which the end faces are conductive and which are held by being clamped between its surfaces. A device of this kind is shown in FIGS. 5, 6 and 7.

The end face 14 of the cartridge 15 applies itself to the angle 16 which latter is integral with the lug 7 and the lug, as in the former case, supports a lever 11 through the hinge 10. As is well known, cartridges of this type comprise at the centre of their end face a pellet 17 which is released when the fuse melts. The hole makes it possible to see if the pellet has been released or, when the box is in the vertical position, has dropped down. A beak 31 holds the cartridge in place.

The other end 18 of the cartridge whose diameter corresponds to the diameter of the fuse contained in the cartridge, is held in a circular insulating sheath 19 hingedly connected, by the folded lug 20, to the lever 21 which latter is pushed in the direction of the angle 16 by the spring 22. Thus, the end face 23 of the other cartridge end is urged against the flat portion 24 of the lever 21.

In the embodiment shown in FIGS. Sand 6, the lever 21 pivots about a metal hinge 25, anchored in the insulating portions of the box A.

In the embodiment shown in FIG. 7, the lever 21 has a flattened end 26 engaging a cavity 27 of the insulating portion of the box, thus being enabled to pivot by contacting the edge 27a provided at the bottom of this cavity.

In both cases the lever 21 is electrically connected, by the flex 28, to the lug 29 which constitutes the second connection terminal, the first being, as in the former case, constituted by the screw 8. It will be noted that the box may be formed in such a way as to comprise an insulating portion 30 of more or less complex shape, situated between the two connection terminals which terminate in cartridge-positioning members. Owing to this arrangement, these members are prevented from moving closer together.

As before, when the lever is pivoted anti-clockwise in FIGS. 5 and 6, its portion 12 causes the cartridge 15 to execute a pivoting movement in the same sense, and this enables the cartridge to be picked up by hand; The replacement of a cartridge is again effected by lowering the lever whereby the transverse portion 13 of the lever is removed from the space occupied by the cartridge in its working position.

In both cases the operation of the lever 11 is facilitated by its stirrup shape and by the fact that the transverse portion 13, in the operating position, extends in a direction substantially perpendicular to the cartridge axis. Thus, it is easy for the fingers to actuate the lever, in order to let it execute a pivoting movement. Besides, the cartridges are completely open to view which makes it easy to see if they are correctly positioned.

I claim:

1. An improved fuse box for a cartridge fuse, of the kind wherein a cartridge fuse is held between a pair of terminal clips arid a manually actuatable fuse ejector lever is mounted in the box by a pivot axis located below the lever of the fuse forpivotal movement to cause rotation of said cartridge tools about one of said terminal clips thereby disengaging said fuse from the second of said terminal clips, wherein said improvement consists in the location of said pivot axis at a point intermediate said terminal clips, and the use of a lever formed with a transversed fuse-engaging member located at a point between said pivot axis and the free end of said lever, said member normally underlying said fuse adjacent one of said terminal clips.

2. A fuse box according to claim 1, wherein said lever comprises a stirrup-like member of fiat, strip-like material with first and second limbs straddling said fuse and pivotally mounted at their free ends, said lever having an intermediate transverse strut bridging said limbs to constitute said fuse-engaging member.

3. A fuse box according to claim 2, wherein said transverse strut is provided in the form of a curved plate.

4. A fuse box according to claim 2, wherein the transverse portion at the base of said stirrup-like member is substantially fiat and so angled that when said lever is in a position underlying said fuse, said transverse portion extends substantially normally to the axisof said fuse.

5. A fuse box according to claim 1, wherein said terminal clips are constructed to engage with terminal end faces of a cartridge fuse, and wherein one of said clips comprises a conductive support pivotally mounted about a hinge situated below the longitudinal axis of a cartridge in position in said clip, said support being urged towards the other of said clips by a resilient member.

6. A fuse box according to claim 5, wherein an insulator sheath adapted to receive the end of a fuse cartridge is hingedly connected to said conductive support above said axis.

References Cited UNITED STATES PATENTS 2,009,235 7/1935 Lewis 337-211 2,004,328 6/1935 Johansson 337-211 2,004,314 6/1935 Dante 337-211 X HIRAM B. GILSON, Primary Examiner US. Cl. X.R. 3372l1

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