US1596234A - Electric fuse - Google Patents

Description

Aug. 17, 1926. 1,596,234

- J. C. BOGLE ELECTRIC FUSE Filed Dec. 4, 1922 2 Sheets-Sheet 1 if M 1% Aug.-l7 1926.

' Y J. c. BOGLE ELECTRI'C FUSE Filed Dec. 4, 1922 2 Sneets-Sheet 2 Patented Aug. 17, 1926.

UNITED s'rmss PATENT-OFFICE.

JOHN 0. soon, or our man, rumors, assrenon ro coo! auc'rnrc conarr, or

cmcaco, rumors, a conrona'rron or more. a

anaemic Ivan.

Application fled December 6,1828. serial Icnoun.

My invention relates to electric fusa and it has special reference to fuses that are known as enclosed renewable fuses.

More particularly my invention relates to an improved electric fuse, in which a chamber containing the fusible element communicates with the outer air through a restricted passagewa com rised ina washer or stop- An object of my -invention is to provide a fireproof enclosed renewable fuse, which com rises elements that may be recurrently use with the exception of the fusible element.

Another object of my invention is to provide a fuse of the character indicated above,

in which the passageways serving to vent the gases from the inte-,

fusefor ex lli the I rior thereo may maintained permanently open and substantially free from clogging deposits whichtend to form from the vars generated at the time of the exploding of the fusible element.

A further object of my invention is to provide a fusible element for a fuse'of the character indicated above, which is so de-" signed as to avoid the production of unnecessary heat and to rmit the heat that is produced to be quic terior of the fuse. I A further object ofmy invention is to provide a device of the tydpe which is of a simple, arable construction and inexpensive of manufactures a Further ob'ects of my invention will apgear upon re erence to the following specication and accompanying drawings, in which- Figure '1 its and artially in non ofan enclosed news is constructed m invention; 1 bled viewtsho'wing in detail, portions of the several elements comprising the fuse of Fig. 1

in'aocordance with in detail.

y radiated to. the exindicated above,"

view, elevation m. v

'Fig. 8 is 'a sectional .view 3-3 of Fig. 1

a removable washer of the general character illustrated in Fig. 1, but in which the cap is not plrovided with a knife blade form of termina taken on line- Fig. 4 is a niodified form of; fuss having Fig. 5 is a sectional view taken on line of 7 Fr .6 t ugh 9 aresectional views of mod 1 e'dforms of washer members;

Figs. 10, 11, 12 13 and 14 are views similar to those of Figs. 1, 2, 8 4, and 5 respectively, but showing a modified form of my invention in which a notch is formed in a f u m m er at the end of the fuse shell,

j providing a passage for the to the exterior of the fuse shell, 133%. 15 is a detail perspective-view of the fuse ink used in connection withmy, inventlon.

Referring to the structure shown in Fi 1, and 3, a fuse link 1 is contained within an insulat shell 2 that serves as a container for the se.. The shell 2 is provided with threaded ferrules 8 and 4 at its ends, which are e ged by; venting washers 5, terminal mem re 6 and cap members ,7.

The two ends of the fuse maybe of similar construction and consequently only the upper end, as shownin-Fig; 1, will bedescribed The fuselink l-may comprise a fusible element 8 formed preferably mthe shape of j, a ribbon and of a metalhaving the profit e fusing characteristics, such as zinc. 'fllSlb eelement 8 is ri 'dly supported centrally of the shell 2 an out of contact with the walls thereof by elongated supporting and connecting terminals 9 and 10. The fusible-element- 8 may be fixed to the terminals 9 and10 by bending over side edges 11 of the terminals for a short distance attheir inner ends, thus forming clamp' means as shown in'Fig. 15. Or if desired, fusible-element ma be soldered to the terminals as indicated in ifiell at9 and 10'.-

apgars in Fig. 15, t terminals 9 and 10 may formed with stifieningribs 12 and 13 along their edges. It is advent in a fuse of this ty to sup rt the 'ble element with an cient rigidity, to revent all possible contact of the element withthe contaming shell, even when the element expands or becomes distorted as a result of excessive v1 total len th of thefuse link and this short length of fusible material is furthermore rigidly supported by the terminals 9 and 10.

' until the ends of the copper link terminals point the copper link in the desirable central location.

The terminals 9 and 10 are preferably con structed of a metal havin relatively high ity hae beenreached.

electrical and heating con activity, such as r. This type of construction has sev.-

COPIPG era important advantages, which will now be outlined. I

One of the problems-of fuse design is to it provide means for carrying away the heat generated by the link when currents of a lower value than what are intended to cause the fuse to'operate are traversing the fuse. That is to say, when normal currents are applied to the fuse the thermal path must be ad uate to carry away the heat at the rate it lazing applied, once a condition of stabil- The continuous zinc link meets with culties in that there is a thermal adient from the hottest point or points to t e outer ends, which carry away the 'heat of the fuse proper .to the external parts exposed to the air.

The addition ofcopper terminals-of sufiicient size extending part way into the shell of the fuse from, bot tive heat' such that the normal cnrrent'is not sufficient to produce any great amoizntof heat in the copper itself. Therefore, by far the greatest amount of heat generated by the fuse link comes from the short zinc strip lying be-,

tween its copper terminals, and the co per terminals having no great amount of eat produced therein are much better enabled to carry off the heat produced in the zinc. A two-foldspu is thus accom lished, first, of limiting t e total quantity 0 heat generated by the normal current, and, second, the provislon of a betterthermal path to the out- 1. ble element 8 when melting will be deflected -side thancan be obtainedfrom' a linluziade entirely of zinc:

Theforegoing description has" related solely to the advantagesof 'thi's'linkf-under normal current COHdltlOIlS-x I shall now out line the advantages of this link undershort circuit conditions.

, tilized lin ends, limits the effec-: "length of the zinc strip which is connected between these copper terminals.v The crosssection of the copper terminals is- ,shell member.

118 may ence has shown that the zinc first melts at its hottest point or oints, then volatilizes in a resulting arc. 'l he are or arcs thus established tend to continue as long as they are fed by metallic vapor from the vola- The duration of this process of volatilization determines in fuse design the violence of the short-circuit conditions within the fuse.- Naturally anything tending to limit the length of time and the amount of metal so consumed tends also to reduce the destructive force produced within the fuse barrel.

I have found on repeated tests that the are fed by the burning zinc strip continues are reached. At this terminals exert a cooling action on the arc and the latter is promptly extinguished with no appreciable burning of the copper link terminals. l V, 1

In a solid zinc link under short-circuit conditions, I find that the whole link is destroyed, even that portion of the link exin the ends '0 the fuse I to conform to the contour of washer 5. The

ends of terminals!) and 10 are then bent downinto contact withthe faces of wash em 5.

The washer-'5 comprises a cup-shaped shell member 16, having a body portion of sub- .stantiallycylindrical'shape and having a rounded .or dome-shaped inner end 17 It has been found that a shell member of this shape can be very quicklyand easily inserted within theferrules a and 4. The shell member 16 is rovided on its interior with means comprising baflle plates 18 for formmg a tortuous. venting passage'through the substantially at the center of the vdomeshaped portion 17 and permitsthe gases produced in the shell 2 to escape into the washer shell 16. The opening 19 is located in the position shown in order that the articles of melted metal thrown from the usiaway from this 0 ning bv the dome-sha d I lily 1 latesn. 1

aralle relak T portion 17, there yzavoidin the possibi of clog 'ng this passage... e heme positioned in ced "1m I An opening 19 is provided.

tion by wire rings 20, suc l ass own in Fi 1. Openings 21 are provided in the be e "plates 18in order to provide passages therevided with a centrally located opening for permitting the gases to pass out ofthrough. It will be noted that the;openings on adjacent bafile plates are located in offset relation with respect to each other in order that a tortuous passage will be formed.

flange 24 for engagement with the outer minal- 9.

edge. of the ferrule 3. The disc 22 is proshell 16.

In the structure shown in Figs. 1, 2 and 3,

a portion of. the flange 24 is cut away at 26 in order to provide space for the linkter- The ferrules 3 and 4 may be formed with threads 27 for engagement with the insulated shell 2. -The'outer ends of the ferrules 3 and .4 are provided with inturned flanges 28 for engaging the terminal 6 and flange 24. v

The terminal 6'may be provided with a. knife blade 29 which may be fastened by g rivets 30 to a strengthening plate 81 and a base member 32-which engages the flange 28on ferrule 3. The flange-28 may be provided with a pin 83 extending outwardly through a slot 34 in, the base member 32. This pin and slot serve to retain tbelmife blades 28st eachl'end of the fuse intheir proper relative an larp'ositions. An alternative construction-def shown in Fig.- 11 where" the flange and the base member are provided respectively, with coacting detents 33 and 34 for 'a purpose similar to the .above described pin and slot construction.

The terminals 9 and 10 are provided at their outer ends with openings Bdand. 36 respectively, opposite the openings 25; in the shell members or washers 16. The plate 31, basemember 32 and knife blade 28 are also provided with coaxial openings 37,38 and 39 respectively, forming apassage forthe The terminal member 6 is retainedinpoe 'sition at the outer end of ferrule Bby means 'gof theendcap 7, which is provided with threads 40 fol-engagement with the ferrules.

The modification shown in Figs..4-and 5,- is similar in construction .to the type above described, but is formedwith a special typee of end ca 41, since in this structure t knife bla e term nals 6 are omitted. The end cap 41 is formed to cover completely the end of the fuse with the exception of opening 41 whichjis for a. purpose correspond tofth at of opening 39. in-Fig l 1. In ot errespects, thectmstruction as Figs. and rfi does not materially; differ from that above described? provided with the integrally formed annular t nd-scope be im 1I claim as new and desire to secure by of washermember Fig. 6, eplates 42 are used which as" s so fl es 43. In this form, thebod oi sfil rii dfiiber is provided with an in tegrally formed flange 44 for a pur ose similar to the flange 24 in the type a ve described. k l

The modification of Fi .7. differs from that of Fig. 6 only in t shown of s acing the battle. lates by means of 'embos lugs 45 form on one of the p ates.

In the modification of Figs. 8 and 8, the baflle plates are replaced by a substantially square member 46 having a largemass capable of absorbing the greater portion of the heat of the gases passing throu h the washer. In this type the gases are a owed to pass through the o nings 47 between the cylindrical walls of t e shell and the sides of the square member 46.

- In the structure-0f Figs. 9 and 9 certain of the baflle plates may be provided with t a""method is openings 21 which are formed simply by cutting of! a segment of the plate at its edge. Openings formed in this manner facilitate the manufacture of the baflle plates.- In this structure the shell member is shown with a disc shaped cover 22' whichis welded at 22 to the shell member.

The structures shown in Fi 10 through 14 inclusive differ from those s own in Figs. 1 through 5 only in the details above pointed out an in the alternative manner shown in which the terminals 9 and 10 on the fuse link are passed to the exterior of the container. In the modification shown in Figs.

'As aconsequenoe, the washer member 50 flange having need not be provided with a a rtlon cut away.

understood that many modifications. may .be

@inade therein without departing from the) of the appraised claims, and v 'tations should a upon my invention as ara -f I i fcifica-l y pointed out in the claimsa desire t-hatonly such as-arerequired byz the I y my invention,"

Having thus descri ters Patent in the United Statw, is: I

1.- .A washerv fora renewable'electric fuse,

comprising a shell member, a plurality .of

spaced substantially parallel baflie plates fitted into the interior of said shell member,

and an opening'through each of said baflle own in lates,'the openings through adjacentv plates L ing positioned n effect relation with respect-toeach' other to provide a passa throughsaid shell member. r

'2. washer for anenclosed fuse comprising a shell member, a 'plurality-o'f bafle.

'le I have shown and described several "embodiments of my invention, it is to be tortuous plates in the interior of said shell member, and means for positioning said plates in substantially parallel relation comprising annular spacing members.

3. A washer for an enclosed fuse comprising a shell member, a. plurality of bafile plates in the interior of said shell member, and means comprising wire rings between said plates for s acing said plates in substantially paralle relation.

4. Means for stopping the end of a cartridge type fuse, comprising a substantially cylindrical shell member provided with a rounded end for insertion into the end of said fuse, an opening substantially at the having a forced fit with the walls of said shell member, said disc being plrovided with a; flange for engagement with t e end of said use. i

In witness whereof, I have hereunto subscribed my name.

JOHN C. BOGLE.

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