US991005A - Fuse-case. - Google Patents

Description

T. E. MURRAY. FUSE CASE.

. APPLICATION FILED OCT. 17, 1910.

991,005. Patented May 2,1911.

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THOMAS E. MURRAY, OF NEW YORK, N. Y.

FUSE-CASE.

Specification of Letters Patent.

Patented May 2, 1911..

Application filed October 17, 1910. Serial No. 587,365.

To all whom it may concern:

Be it known that I, THOMAS E. MURRAY, a citizen of the United States, residing at New York, in the county of New York and State of New York, have invented a certain new and useful Improvement in Fuse-Cases, of which the following is a specification.

Y The invention is a'fuse case, and consists in the construction thereof, whereby the use of bolts or other separate fastenings and of cemented joints between the parts to be united is obviated, while at the same time the whole device is simplified and made exceedingly strong so as to be capable of withstanding the shock of a blowing fuse conveying currents sufliciently great to shatter ordinary fuse cases. The fuse case body is a tube of or reinforced with, strong metal, such as iron or steel, which is united and locked to its end holders, which are preferably of porcelain, by simple bending of its own material, and the metal'contacts electrically connected to the fuse strip are also in like manner joined to said holders.

In the accompanying drawings lligure 1 is a perspective view of my improved fuse case. Fig. 2 is a longitudinal section on the line as, w of Fig. 3. Fig. 3 is a transverse section on the line 1 y of Fig. 2, and Fig. 4. is a perspective view of the tubular fuse case body detached from the end holders.

Similar letters of reference indicate like parts.

The fuse c'ase body A. is to be made of metal, preferably iron or steel, in tubular form, and, as shown in Fig. 3, is provided at each end with two flat and parallel projections B, C and D, E. The holdersF, G are alike, and are made preferably of porcelain or other refractory insulating material. Each end holder is flanged, as shown at H, and is provided with two parallel slots to receive the projections B, C and D, E. The inner ends of the slots are preferably shouldered at I to form abutments for similar countersunk shoulders J formed at the junction of the projections B, C, l), E with the case body A. At the outer ends of the slots are countersunk shoulders, against which shoulders the flanged over extremities K of the projections B, O and D, E bear. In this way the case A is firmly locked in the holders by bending its own material and without the use of bolts or other separate fastening devices, or of cemented joints. Centrally disposed in each holder is a longitudinal slot, through which slots pass the fuse strip L, which extends through the case body A. The slot is preferably somewhat larger in cross sectional area than the fuse stri and may be filled with plaster or like material, as shown at M. On the outside of each holder is a metal contact plate which is bent to cover the bottom and two sides of the holder, as shown at N, O, P, and abuts against the flange H. Said plate is secured in place by integral bent over lugs Q which rest upon the upper surface of the holder. Another portion R of the contact plate extends upwardly from the bottom and lies against the outer face of the holder. In the portions R of the contact plates are formed slots to receive the extremities of the fuse strip, so

that said fuse strip is thus electrically connected to said contact plates.

In assembling the device, the projections, as B, C, at one end of the case body are inserted and secured in the holder as described, and the exterior metal contact plate is applied and the fuse strip is inserted. The space in the slot' in the holder which is not occupied by the fuse strip is then filled with wet plaster which is permitted to harden, and the contact plate being applied, the extremity of the fuse strip is electrically connected thereto. The body of the fuse case is filled with any suitable comminuted refractory insulating material, as shown at S, and, finally, the other holder is applied in the manner already described. The resulting structure is solid and compact, free from bolts or like fastening devices, or from parts joined by cement, and hence having no parts to work loose orbecome separated. It

"is especially designed for fuses conveying heavy currents, and to withstand the shock incident to the blowing of such fuses. The flanges H form barriers between the metal body of the fuse case and the metal contact plates of the holders so as to prevent any possibility of a spark passing between them. It is preferable to provide the case body inside and out with a paper sheathing, T, U, to protect the metal from oxidation, and as a guard to prevent contact of the operators hand with the metal. The metal must be strong enough to resist the shock, but its relative thickness to the sheathing is immaterial. so that the tube may be correctly described as either a metal tube sheathed with paper, or as a paper tube reinforced with metal. In using the device, the holders are inserted in the usual spring slips connected to circuit terminals, so that circuit is completed through the fuse by way of the metal covering plates, which, as is obvious, are completely insulated from the fuse case body by the solid refractory material of the holders.

1 claim:

1. The combination of a tubular case body of metal, holders of refractory insulating material, means for securing said case body at its ends in said holders, a fuse strip in said case body, and contacts on said holders electrically connected to said strip.

2. The combination of a tubular case body of metal, holders of refractory insulating material having openings receiving the ends of said case body, in which openings said case body is secured by bending the material thereof, a fuse strip in said case body and said holders, and contacts on said holders electrically connected to said strip.

3. The combination with an inclosed fuse strip, of a tubular case body of flexible metal, holders of refractory insulating material having openings receiving the ends of said case body, and flexible metal contact plates on said holders electrically connected to said strip; the said case body and the said plates being secured to said holders by bending the metal into suitable engagement therewith.

4. The combination of a tubular case body of metal having integrally formed projections at its extremities, holders of refractory insulating material, means for securing said projections .in said'holders, a fuse strip in said case body and said holders, and contacts on said holders electrically connected to said strip.

5. The combination of a tubular case body of metal having integrally formed projee tions at its extremities, holders of refractory insulating material having slots receiving said projections and provided with countersunk shoulders at their ends, over which the extremities of said projections are flanged, a fuse strip passing through said case body and said holders, and contacts on said holders electrically connected to said strip.

6. The combination of a tubular case body of metal having integrally formed projections at its extremities, the said projections being bent to form shoulders at their junctions with said case body, holders of refractory insulating material having slots receiving said projections, each slot having a countersunk shoulder at its ends, the inner shoulders forming abutments for the said first-named shoulders and the outer shoulders receiving flanged over extremities of said projections, a fuse strip in said case body and holders, and contact plates on said holders electrically connected to said stri 7 The combination of a tubular case body of metal, holders of refractory insulating material, means for securing said case body at its ends in said holders, a fuse strip extending through said case body and holders, and a contact plate covering two sides and the bottom of each holder and having a portion extending over the end face of said holder, the said last-named portion being electrically connected to an extremity of said fuse.

8. The combination of a tubular case body of metal, holders of refractory insulating material, each having a flange at one end, means for securing said case body at its ends in said holders, a fuse strip in said case body and holders, and contact plates on said holders and electrically connected to said strip; the flanges on said holders being disposed between said case body and said contact plates. 7

9. The combination of a tubular case body of metal, holders of refractory insulating material, means for securing said case body at its ends in said holders, a fuse strip and a filling of comminuted refractory insulating material .in said case body, and contacts on said holders connected to said strip.

10. The combination of a tubular case body of metal holders of refractory insulating material, internal and external sheathings of fibrous material on said case body, means for securing said case body at its ends in said holders, a fuse strip and a filling of comminuted refractory insulating material in said case body, and contacts on said holders connected to said strip.

11. A. fuse case having an inclosing case of non-conducting fibrous material reinforced with metal.

12. A. fuse case having a tubular case of metal with inner and outer sheathings of non-conducting fibrous material.

13. The combination of a tubular case body of metal, a fuse strip therein, holders of refractory insulating material, means for securing said case body in said holders, contact plates on said holders electrically connected to said fuse strip, and barriers of insulating material interposed between said case body and said contact plates.

14. The combination of a tubularcase body of metal, a fuse strip therein, holders eennoos g;

of refractory insulating material, means for In testimony whereof I have aflixed my SGCHI'iIIIg said case bgldyl din saild holdefi's, consignature in presence of two witnesses. tact p ates on said 0 ers e ectrica y connected to said fuse strip, and barriers of in- THOMAS MURRAY 5 sulating material formed integrally on said Witnesses:

holders and interposed between said case GERTRUDE T. PORTER, body and said contact plates. MAY '1. MCGARRY.

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