US1474146A - Fuse cartridge - Google Patents

Description

Nava 13 1923. n `1,474,146

F. A. FELDKAMP FUSE CARTRIDGE Filed Aug. 123, 1919 AoRNEYs Patented Nov. 13, 1923.

UNITED STATES FREDERICK A. EELDKAMP, `or NEWARK, NEW JERSEY.

EUsE CARTRIDGE'.

Application led August 23, 1919. Serial No. 319,303.

To all w 710m t may concern A Be it known that l, FREDERICK A. FELD- Kairr, a citizen of the United States, residing at Newark, in the-county of Essex and State of New Jersey, haveiinvented certain new and useful Improvements in Fuse Cartridges; and l do hereby declare the following tobe a full, clear, and exact'description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had tothe accompanying drawings and to characters of reference marked thereon, which form a part of this specification. n

The present invention `has reference, gencrally, to improvements in 'fuse cartridges.

The invention has for its principal object to provide a novel means, in combination with the general `fuse cartridge construction, adapted to reduce and relieve sudden internal pressure within the fuse container, due to a sudden blowing of the fuse. thereby preventing bursting or rupture of the container and other attendant dangers.

Other objects of this invention, not at this time more particularly enumerated, will be clearly understood from the following d etailed description of the same. i

lilith the objects of my invention in view, the same consists., primarily, in the novel construction of fuse cartridge hereinafter set forth; and, furthermore, the invent-ion consists in the novel arrangements and combinations of the various parts, as well as in the details of the construction thereof, all of which will be hereinafter more fully de-V scribed and claimed.

The invention is clearly illustrated in the accompanying drawings, 1n which Figure l is a longitudinal section ofa fuse cartridge made according to and embodying l the principles of my present invention; Figure 2' is an end elevation of the same; and Figure 3 is a cross-section through the same taken on line 3-3 in said Figure l.

Figure 4 is a longitudinal section of a slightly modified construction of my novel fuse cartridge, Figure 5 is a longitudinal section of a multiple fuse cartridge embodyingthe principles of my present invention.

Similar characters of reference are employed in the herein above described views, to indicate corresponding parts.

It is well known that upon the blowing of the fuse element of fuse cartridge by a short circuit, an internal pressure created `within the cartridge or container, which is due both to vaporization of the fuse metal, as wellv as to thee-Xpansion by the generated heat of air present between granules of the filler usually surrounding the fuse. .This

pressure is of considerable magnitude, and

if not quickly reduced or relieved, may result in the bursting of the cartridge or at least in a serious rupture thereof. In order to relieve the internal pressure created by the gases resulting from the vaporization of the fuse, it has heretofore been customary to provide escape openings or vents in the ends of the ferrules, and in order that the granular filler substance should be prevented rfrom falling or passing out through and passage of the gases therethrough, or as in the case of4 wire mesh or perforated discs, the interstices therein become so clogged or choked up with the granular filler substance .that the passages therethrough become impassable, thus counteracting the very function of venting the gases and relieving internal pressure desired to be accomplished. Even `in the event that the gases Clo-reach the vent openings of the ferrules, and pass out.- wardly therethrough, the same `are in such a state of high ten'iperature, that there lis always danger of igniting indammable material in theneighborhood of the fuse cartridge. That such is thecase has been est-ablished by underwriters tests in numerous instances. i

,It is the primary object of my present invention to combine in, the structure of a fuse cartridge a novel means whereby not only will the gases occurring after the blowing and vaporization of the fuse element be quickly liberated from the interior of the cartridge or container, but the same will also be quickly. reduced in temperature, all

of which `will result in a very rapid reduc-y tion of internal pressure within the cartridge or container, thusk rendering the fuse cartridge much safer in use, and assuring against bursting or rupturing of the same under the conditions above mentioned. p

l/Vith, this object in view my novel construction ot fuse cartridge comprises a suitable tubular casing 1 made ot some desired variety ot insulating material, the same heing closed at its respective ends by means ot metallic terrules 2, the same not only serving to close the interior chamber 3 provided by the casing, but also serving as electrical contact elements to be received in the clips provided tor holding the tuse cartridge in use, and electrically connected in the circuit to be served by the same. Centrally disposed relative to each ferrule 2, and secured to the enti walls thereof by solder or other suitable tastenii c means are inwardly extending anchor studs or contact posts 4; to which are secured the respective ends et a i'use element 5 mounted to extend longitudinally through the said interior chamber The intermediate space of the chamber 3 about the luse element 5 is filled with a granular filler-powder 6, such as is commonly employed in the construction oil ruse cartridges. Disposed in the end portions of the chamber 3, between the tiller powder and the end walls ot the lierrules .4, and extending for a `considerable or substantial depth, are layers ot metallic wool T or .other metallic material adapted to provide a highly porous mass, or a body of metallic material interspersed with a multiplicity of interconnecting interstices throughout its extent. I lind that the substance which gives most er:n cellent results, considering` the purposes in view, is what is known as steel wool, although I do not necessarily limit myself to the use of this material alone, since any metallic wool. the metal ot which possesses conuiaratively high melting point, or any metallic shavings, ilings or chips of comparatively high meltingpoint, which when massed together provide the desired multiplicity ot interconnected interstices may be used, and will serve more or less successfully the purposes I have in viewY The cud walls oit the ierrules 2, against the inner sides oit which the said layers of metallic wool or the like abut, are provided with a number of vent holes or per'torations 8. In some cases it may be desirable to `re-enforce or strengthen the end walls of the terrules 2, in which case a disc 9 ot metal or other suitable material may be arranged and suitably secured against the inner side of Said end walls ot' the ferrules 2, said disc 9 being pro vided with vent holes or per'torations 10 to register or aline themselves with the vent holes or perforations 8 of the ferrules` all of which is more particularly illustrated in figure l ot the drawings. While I have described the layers 7 `of steel wool or other suitable material as disposed at each end of the chamber 3 intermediate the filler powder 6 and the terrules 2, itt desired.r the same may be omitted at one end of the chamber at one cud ol the chamber B, the vent holes or p rtorations 8 being omitted from said teil 'thus engaged by the said filler i'iovfder.

Referring now, more particularly, to lligure ol" the drawings, I have shown therein how the principles o'li' my present invention may b wiriplied to a multiplo if'use cartridge, such, tor example, as is in my prior application for Letters-Patent, tiled March 31, 1917, and bearing Serial No. 158,809, result ing` in Patent No. 1,268,807. In this view the reference character 11 indicates the tubular casing having a lined terrule l2 at one cnil, and a movable vlerrule 18 at the opposite end. Arranged in that end oli the casing); bearing the niovable 'lier-rule 13 is a plug 1st in which is imbedded the ituse contact pins 15 with which the contact element 16, carried by the niovahle fcrrule 18, may be selectivelyv engaged to brine` into the circuit any desired one ot the tuse elements 17 extending rcspectirely from said contact-pins l5. Suit able partition members 18 are provided to enclose each fuse-eleinent 17 in its own individual compartment. Connected with said tired licrrule 12 is an inwardly extending common contact-post 19 with which the several fuse elements 17 are connected to electrically engage the same with said lixcd terrule 12. rlhe )artition members 18 terminate short ot the end wall of said liXed lierrule 12 leaving an annular free space about the shank of said contact post 19. The several elements 17 are each surrounded in their respective compartments with the usual granular filler powder 20, which also extends partially into the annular liree space above mentioned. Arranged in said annular tree space between the filler powder 2O and the end wall ot said fixed terrule l), is a layer ot steel wool or the like 21, and the said end wall of the Fixed terrule is provided with one or more vent holes or pertorations 22.

lxfben a` 'luse cartridge constructed acrording' to the principles ol my present invention is blown, the heat expanded air and the gasef-, resulting trom the vaporization of: a portion oilz the. fuse metal imn'iediately gives risc to an internal pressure within the casing. The expanded air and gases are tmced by this pressure through the filler powder, and are driven into the layer of metallic wool or the like penetrating and passing' through the interstices thereot` until the vent holes or perforations in the adiacent 'terrules are reached, through which they are passed into the external atmospliere. By passing through the interstices inV said layer ot metallic material, the temperature ot the air and gases is quickly reduced by contact With the comparatively cool metal, and consequently the volume thereoi is diminished as they cool, thereby .immediately tending to reduce the pressure trom such cause, as well as by the reduction ot' their volume due to the ejection thereof' through the vent holes or pertorations of the terrules. Another advantage of the layer oi? metallic wool or the like is that the same is more or less elastic to its mass, and consequently cannot` be choked up with filler powder, since the interstices termed extend in all directions, and new openings or pas sages tor the gas open up around such particles ot powder as may possibly penetrate the metallic wool vlor a short distance, so that the may always `lind a point oli' escape.

l'n this respect my arrangement is much su perror to perforated or wire mesh washers or discs, the interstices of which all extend in one direction so that the powder may very quickly penetrate the same andv quickly choke them up, thus obstructing the desired venting et the gas. Furthermore, the per- 'rorated orrwire mesh washers or discs do not successfully bar the escape ot some powder therethrough when handling the fuse cartridges, whereas the layer of steel wool or the like provides such a multiplicity of devious passages that the powder can not penetrate through the same in astraight line and consequently is soon blocked against escape. The periorate or wire mesh discs or washers do not provide a sutlicient mass of metal to have an appreciable cooling effect on the heated gases.

The general result ot my novel structure is that the heated gases are quickly vented trom the interior ot the cartridge so that pressure upon the latter is so reduced as to prevent rupture or bursting of the same; are quickly reduced in temperature before their iinal escape so that little danger of ignitin inflammable material exterior of the cartridge existsgand are so cooled and reduced in pressure as to nally escape noiselcssly through the said vent openings or pertorations ot the ferrules.

My invention also contemplates the use of the steel wool or other like material in combination with suitable vents in the fuse containing cartridge even though the liller owderV is omitted ifrom the structure, an the iusc element enveloped only by the air con lined within the containing cartridge.

l claim y l. A fuse cartridge comprising a tubular container, metallic end ferrules closing the ends of said container, an internally disposed tuse element interconnecting said end lcrrules, a granular i'illerv powder enveloping said fuse element, at least one ot said end 'errules having vent openings in its end wall, and a layer of metallic wool capable ot rapidly conducting heat interposed between said vent openings and said filler powder, said metallic wool having a comparatively high melting point.

2. A. fuse cartridge comprising a tubular container, metallic end terrules closing the ends ot said container, an internally disposed tuse element interconnecting said end ierrules, a granular filler powder enveloping said 'fuse element, at least one ot said end terrules having vent openings in its end wall, and a layer of steel wool ol substantial depth interposed between said vent openings and said ller powder.

3. In a device of the kind described, a containing cartridge, a fuse element enclosed within said containing cartridge, said containing cartridge having vent means, a granular lille'r powder enveloping said fuse element, and a layer of steel wool Yinterposed between said vent means and said filler powder.

4. In a device of the kind described, a containing cartridge, a fuse element enclosed within said containing cartridge, said containing cartridge having vent means, and a layer of steel wool arranged within said containing cartridge in back of said vent means.

In testimony, that l claim the invention set forth above l have hereunto set my hand this 21st day of August 1919.

FREDERICK A. FELDKAMP.

Witnesses:

GEoRGE D. RICHARDS, BARBARA W. SUTTE'RLIN.

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