Fuse block, particularly for printed circuits

Abstract: Fuse block, particularly for printed circuits, consisting of a small block (1) of insulating material, having a "U" shape, to whose wings (2) are locked two equal terminals (6), each of them provided at the bottom with a coupling (7) for printed circuit and at the top with two prongs (9) designed to receive a head (11A) of a fuse (11), restrained by a small frame (12). From this latter extend two wings (10,20) shaped in such a way as to allow the easy insertion between themselves of the fuse and the subsequent elastic restraint of the fuse.

Description: This invention relates to an improvement made on a fuse block for printed circuits as defined in the preamble of claim 1. It is known that fuse blocks for printed circuits are required to be functional and reliable in time, as well as to have a low manufacturing cost. Fuse blocks designed for the particular technical field mentioned above are already known, e.g. consisting of a small insulating block of synthetic resin, having a "U" shape, with the wings of said "U" in tubular form. To said block are fastened two metal terminals, equal to each other, each of them shaped at the bottom according to a coupling suited to be inserted into a corresponding seating of the printed circuit, and defining, at the top, two prongs designed to receive between themselves, by snap insertion, an end of the fuse, with this latter supported by a relative small frame. It is known that the small frame, having a "T" shape, comprises a cylindrical seating disposed longitudinally to the same small frame, suited to receive a fuse, through the initial disposition of this latter coaxially to said seating and to the subsequent pressure exerted on the fuse in the direction of the longitudinal axis of the above-mentioned seating. It is also known that said fuse is assembled on the small frame by hand. The result is a remarkable incidence of said manufacturing phase on the total cost of the whole fuse block (small block, small frame, fuse). The most part of the time employed for such operation of fuse-frame assembling is due to the difficulty of coupling these latter parts manually. It is also known that, when testing equipment employing such fuse blocks, a remarkable number of fuses often result to be damaged. This is followed by the need to provide, also manually, for the replacement of the fuses inserted in the small frames; thus it is obvious that the time required and consequently the costs related to this series of operations increase substantially. Therefore, while maintaining the validity and the practicality of the above-mentioned small blocks of synthetic resin, having a "U" shape, with the wings of said "U" in tubular form in order to receive the heads of the fuse, the main object of the present invention consists in improving the practical (thus economic) aspect concerning the assembly of said fuse-small frame group, with the first one suited to be coupled with said small block. The above-mentioned object is accomplished in accordance with the subject matter of the claims. As a result, a very functional article is obtained, both from the point of view of manufacture, with a substantial reduction of relative costs, and from the user's point of view; the highest reliability of operation is also assured. The features of the present invention will be described further hereinafter, with particular reference to the accompanying drawing, wherein: Fig.1 is an exploded perspective view of the small frame and of the fuse; Fig.1A is a perspective view of the fuse-small frame unit assembled; Fig.2 is an exploded perspective view of the complete fuse block; Fig.3 is an exploded lateral view of the small frame and of the fuse; Fig.3A is a lateral view of the small frame- fuse group assembled; Fig. 4 is an exploded lateral view of the complete fuse block. With reference to said figures and particularly to figs. 1 and 3, the numeral 12 designates a small frame basically having a "T" shape, suited to hold a fuse 11. Said small frame 12 is provided with "L"-shaped wings 10 and 20, consisting of respective sides 10A, 20A and appendices 10B, 20B, with these latter parallel to the upper part of said small frame 12, elastic to lock properly said fuse 11 in its seating (as indicated in figs. 1 and 1A). Said wings have the same shape but are directed in opposite senses with respect to the transverse axis of the small frame. The wings 10 and 20 are offset to define relative openings, respectively provided between the side 10A and the appendix 20B, and between the side 20A and the appendix 10B, which together provide a seating 40 oriented diagonally with respect to the axis of said small frame. Said fuse 11 is assembled to said small frame 12 by inserting the fuse into the seating 40 mentioned above, as indicated by arrow A in fig. 1. At this point, a semi-rotation is sufficient, as indicated by arrow B of fig. 1A, to insert said fuse 11 into said frame 12 very quickly. This latter is provided, at the top, with a window 12B which makes it possible, at any moment, to verify the correct operation of said fuse 11, particularly when this latter is set up. The conducting heads 11A of said fuse protrude from said wings 10 and 20, but remain covered by the upper part of said small frame 12. With reference to figs. 2 and 4, the numeral 1 designates a small block of synthetic resin having a "U" shape, provided with two wings 2 provided with special hollows into which are inserted, by a known method, two metal terminals 6, each of them having two vertical prongs 9 suited to receive said conducting heads 11A of the fuse 11. The elasticity of said prongs 9 allows an adequate fastening of the conducting heads 11A of the fuse 11 when this latter is inserted into said prongs, thus ensuring a safe electric connection. The mutual assembly between the heads 11A and said prongs 9 of said terminals 6 is quick and easy, and it may be carried out by light pressure of the unit comprising the small frame 12 and the fuse 11 on the small block 1. Furthermore, every terminal 6 is shaped, at the bottom, according to a coupling 7 suited to be inserted into a corresponding seating of the printed circuit. Obviously, the surface of mutual contact among said terminals 6 and said heads 11A is a function of the maximum bearable current of the fuse 11. The particular, and original, conformation of the technical solution provided by the present invention (i.e. the wings 10 and 20 of the small frame 12) makes it possible to obtain, on the one hand, the same elements through simple technological operations (by molding of synthetic resin) and, on the other hand, a simple and quick insertion of said fuse into said small frame 12.

Claims: Fuse block, particularly for printed circuits, consisting of a small insulating block (1) having a "U" shape, to whose wings (2) are fastened two metal terminals (6), equal to each other, each of them shaped at the bottom according to a vertical coupling (7) suited to be inserted into a corresponding seating of the printed circuit, and at the top according to two vertical prongs (9) designed to receive between themselves, by snap insertion, a head (11A) of a fuse (11), with this latter held by a small frame (12), basically having a "T" shape, to which it is elastically restrained, corresponding to the lower face of the relative base, through removable locking means in a single body with the same base, said fuse block being characterized in that said locking means are placed in a central position of the small frame (12) and comprise at least two wings (10,20) defining seatings to receive and elastically restrain said fuse (11). Fuse block according to Claim 1, characterized in that said wings (10,20) have coaxial seatings shaped complementarily to the body of said fuse (11). Fuse block according to Claim 2, characterized in that said wings (10,20) together define a diagonal seating (40) to receive said fuse (11), with said wings suited to allow the subsequent rotation of the fuse from said diagonal position to its longitudinal position with respect to said small frame (12). Fuse block according to Claim 3, characterized in that said small frame (12) is provided with wings (10,20), having an "L" shape, consisting of respective sides (10A,20A) and appendices (10B,20B), with these latter parallel to the upper part of said small frame (12) and having the same shape but being oriented in opposite senses with respect to the transverse axis of the small frame (12). Fuse block according to Claim 3, characterized in that said wings (10,20) are offset with respect to the transversal plane of said small frame (12), in order to facilitate the insertion of the fuse (11) into said diagonal seating (40).

Inventors: BABINI EZIO, BABINI, EZIO
Applicants: FITTINGS IND SRL, FITTINGS FOR INDUSTRY S.R.L.
Application year: 1991
Main classification: H01H85
IPC codes: H01H85, H05K3