US1562984A - Incased fuse - Google Patents

Description

Nov. 24, 1925.

T. E. MURRAY INCASED FUSE l Filed April 4, 1921 .40., electric weldi rPatented Nov. 24, 19255. i

THOMAS' E. MURRAY, or nnooxmm, NEW Yoan.

moesen FUSE.'

Application led April 14, 1921. Serial No, 458,353.

l T all .whom it may concern."

Be it known that I, THdMAs E. MURRAY,-

a citizen of the United States, and4 residentA of Brooklyn, New York, have invented certain new and useful Improvements in Incased Fuses, of which the following is a specification.

My invention aims to provide an incased electric fuse which can be cheaply manu- `factured and which has other advantages referred to in detail hereinafter. v A

Fig. 1 is a perspective view of a complete incased fuse; j v vFig. 2 isa horizontal section ofthe same with the fuse strip removed;

Fig. 3 is a yvertical section with the fuse strip in place;

Fig. 4 is a transverse section on the' line 4 4 of Fig. 3, with the fuse strip omitted.

$0 The fuse proper which I have indicated at A may be 'of any usual or suitable type.-

It is preferably of the construction described in the atent of Murray and Murray, dated Novem r14th, 1922, No. 1,435,651. It con- 5 sists of a'strip of fusible metal withf-forked ends B for attachment to terminals andwith the usual contractedcentral portion and an 4envelope of asbestos or other refractory insulating material extended over it continul ously between its terminals.- This covers the contracted ortion atA the center, where Athe fuse melts t roughv in use, and prevents arc-' ing or the passage of current from the broken end' of the fuse outward and thus Il permits the use of a metal casing which l .would `otherwise be dangerous.

The case consists of a metal box with sides 1, ends 2. andan arched` top 3 and a flat bottom 4, tle parts being put together by (as by drawing the top, sides and ends 1nI one piece and welding the bottom on,a or by forming two halves and weldin them together on a Icentral longi' tudin plane) or in an other usual'or suitable way. In the en sI of the casing are porcelain insulating blocks 5 extending outward Aand inward beyond-the metal and held' against removal outward by` shoulders 6 on the inside and cemented with plaster '62 Each block carries a conductor of copper extending outward in the form of a lat blade 7 adapted for easy insertion between `the blade terminals of the line intowhich the fuse is to'be inserted. Within the case the terminals have their ends 8 bent-at an angle, 55

`as shown, and preferably in a plane transverse to the plane of the outer` portions or blades 7 the "inner ends 8 being threaded for screws 9 which fasten 4the terminals of the fuse vstrip with the latter in the arched 50 position shown.

The bottom 4 of the box is provided with an opening 10 through whichv a screw driver may be inserted to operate the screws 9, the ends 8 of the terminals being set at such an 55 angle as to facilitate this operation, and the opening 10 being large enough also to permit the ypassage of the fuse strip. The opening is normally covered by a plate 11 passing through afslot in the end of the box and 7. having an enlarged head 12 by which it can be pressed in or can be pulled out tonn- Wer the opening. A wedge 13 is provided, by bending' up the bottom orvas a separate piece, which-enga es the end of the cover u when the latter 1s shoved inward. The cover is provided with a slight boss 14 which prevents its complete withdrawal through the slot in the endof the box and which also locks it in positively under thel wedge 13, the latter forcing it down against the bottom of the box. y When a fuse burns out the entire case will vbelifte'd'out of the terminals and will be opened at the bottom and.v a new fuse inserte Whileathe fuse is in place ythe o ening at the bottom is generally inaccess le because of its closeness to the plate 15 on which the line terminals, indicated in dotted lines atl, are mounted, The entrance ofthe box is thus concealed andprotected.V

Though I have described with greatparticularityvof detail certain specific embodiments of my invention, yet 1t Ais not to be understood that the invention is restricted to "the particular lembodiments disclosed. Various modifications in detail'thereof may be made by those skilled in the art without departure from the invention as. defined in the followingclaims, 1- 100 That I claim is insulating blocks carried in the ends thereof 1. A fuse casing carrying terminals passwith a space surrounding them and a plast-ie 10 ing through the opposite ends thereof in filler within the easinr between the insulatcombination with an arched fuse strip Withing' blocks and the metal. 5 in the easing, said. casing havingr an opening In witness whereof, I have hereunto signed on the concave side of the strip through my name. which the latter may be removed or inserted.

y 2. A fuse casing comprising a metal box, THOMAS E. MURRAY.

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