t'tttoutetl Nova lid, liltlti rarsur ‘cures 2&11360 ELE‘JTRIC FUSE i (A This invention relates to electrical cartridge type fuses. Such fuses in their usual applica sealing relationship over the ends of the body portion ill by the brass, copper, or other conduct~ tion are used to open a circuit when the current lug metal ferrules l and ill respectively. Fer ?owing in the circuit exceeds a normal rating rule construction of this lrind is well known in for which the circuit is designed. 5 the electrical industry and need not be elab~ In the use of electrical equipment it is i'ound orated, upon here with the exception that it is that overloads occur, such as when several cur necessary to include a sealing cement or other rent consuming devices are simultaneously material at the juncture of the tube and the started, resulting in circuit current values which conduction elements it and it which will pre would be harmful if continued. Time is a factor, 10 vent moisture within the fuse body from leaking however, and for relatively short periods of time out. As an alternative construction the caps such overload currents do not create any undue “ I construction, not shown, heating in the circuit which would cause fau ‘715 ii and it‘ or are t or be detrimental to either the current sl' gle elements rather than two or; lines of the circuits or to equip installed in the lines. eleinent is constructed of is an object of this invention to provide a fuse oi a construction which will permit over~ ' an low alloy of lead pointtin depending such upon locals for short periods of time without destroye be current capacity desired. This fusible ele~ ing the fusing element but which will open the meat is a small hollow capillary tube, disposed circuit readily upon continued overload. centrally within the fuse body and closed oil at It is a further object of this invention to pro~ its upper and lower junctions with the fuse caps vide a fuse oi’ plug-type construction which will ii and ill. in order to locate the fuse element permit short duration over-loads without re“ with respect to the caps, punched indentations sorting to moving parts such as dash pots and i8 and it’ are provided in the upper and lower springs. caps providing a projection on the inner surface A still further object of the invention is to of the cap at which point the fuse element may provide a fuse which is certain in its capacity to be hired in place in electrical contact with the function and which may be easily manufactured caps Mend it sealing the ends oi’ the fuse ele without any especially costly elements. ment to. The length of fusible element may be Other and ancillary objects of the invention made slightly in excess of the distance between may appear throughout the description, the de . the inner surfaces of caps ii and i2 when as tail drawing, and the appended claims. sembled so that a tight fit is produced to hold it In the drawing, in place. Further insurance of retention of this Figure l is a longitudinal cross section view 35 element in position may be had by slightly fus through a fuse embodying our invention; ing the ends to the caps by the application of Figure 2 is a transverse section View taken on controlled’ heat at the indentations lb and it’ the lines 2-2 in Figure 1; and after ‘the caps El and are positioned over the Figure 3 is an elevation view partly section, ends of the fuse body it. to show conditions within the fuse immediately Two small holes ll and ll’ are provided in one prior to the time when the fuse blows or melts. in Figures 1 and 3 are shown the plug-type idge fuse construction 1.,hich comprises an latiug tubular body l constructed of glass, Wall of the fuse element, one of which is located in the proximity of the lower fuse cap and the other, in the proximity of the upper cap. A small quantity of water is introduced within ‘ e '" ‘ e body to an elevation above the lower fuse element with the fuse in a _, owing, bottom as is required for operation. A method of performing this operation ‘e to provide a small hole in the body of the body rlcal conducting metal of he; temperature such brass the or in one of the metal caps as at it through “3 the ‘water could be introduced, which in K subsequently be sealed with a drop or’ solder -aving a higher melting point than any t A erat which would be experienced in liquids may be substituted for 2,411,460 a > I - sulating tubular body portion," fuse caps secured water; however, in the description which follows, certain considerations are given which vare based to the ends of the ‘body portion, and a hollow on the use of water. tubular fusible element in electrical association. . ‘ -‘ and sealed off at its ends with the fuse caps, said There is a certain amount of capillary action - ' fusible . element within the bore of the ‘fuse element 15. by the tubular construction of the element itself,- which having openings extending throughitswall adjacent to its ends, and a sup ' ply of liquid partly'?l'ling said body portion to, . .' will carry water upwardly into the tube. This ' a. prescribed level with respect to the location of , action may be increased and the functional ef fects of the fuse varied by ?llingthe interior of . one ofnsaid openings. . I ' 3. In an electric fuse in combination, an in this element It witha drying agent or such nia-v 10 -'terial as felt or glass wool. An excess of water , sulating. tubular body portion, fuse caps. secured to the ends of the body portion, and a hollow tubu over that shown in Figure 1 may be permitted .-lar fusibleelement centrally located with respect j in-the' fuse if it is desirable,'or conversely, this quantity of water may be very slight by locating - to the body portion and in electrical associationv and se'aledo? at its'ends with the fuse caps, said the elevation of the small hole HI lower in the fusible element , having openings extending ,‘fuse.’ During periods» of normal operating 'cur-. through its wall adjacent to its ends, and a sup- . ' rent with the fuse placed in the. line, the ‘element it by PR losses, audit will remain relatively ply of liquid partly filling said body portion to a prescribed level with respect to the location of ' cool. In case of an overload or short circuit, the 20 one of said openings. temperature of the fuse element l5" will rise _ 4. In ‘an electric‘ fuse in combination, an in fuse element to the water within- theelement, . ~ the vapors will be driven o? through the‘upper ' I ings extending through‘ its wall adjacent to its ‘ends, and a‘supply of liquid partly filling-said body. .hole il' until thelevel oi’ the water drops below ' portion'to a prescribed level with respect to the lvb'will receive no abnormal heat transferred to ‘ , . sulating: tubular body portion, fuse caps secured rapidly. It will not reach melting temperature ediately since the water within the tube will‘v _ to and ,in liquid tightrelationship with the ends ,of the body portlon, and a hollow tubularfusible change vstate and bedriven off before‘ its fem-4 peratu're will greatly exceed 212° F. ' As steam element in electrical association at itsends with -_ vapor is generated'b'y' transfer of heat from the. ' the vfuse caps, said fusible element. having open-1 . the hole, and because of. the lower temperature of the shell these vapors will condense and later so location of-one of said openings. ‘ - - 5. In anjelectric ‘fuse in combination, an" in; '. sulating tubular body portion, fuse caps secured‘ _- v. tend to fall back into the lower portion of the ‘ fuse on the outside of the fuse element. Figure ' - to and in liquid tight relationship with the ends I" . ‘of the body portion, and a hollow tubular fusible a shows acondition resulting when. all of the liquid has been driven off from within the tube to the level Just below the lower hole'il and has ’ collected in the form of minute dropletson'the' inner surface of the body H0, at which time the element in electrical-association and sealed off ‘ _-lng‘saidj body portion to'a prescribed level with ._ temperature '- of the fuse element may go beyond respect to the location ofv one of said openings. ' ‘212° F. and may then: reach the melting point 6. In ‘an. electric fuse. in combix'iation,v an in of the fusible material, thus interrupting. the ' electrical circuit. _ v I . v | .' ' at its ‘ends with the fuse caps, said fusible element having openings extending through its‘ wall adja- ' cent to it's ends, and‘a' supply of liquid partly illi _ s'ulating tubular body-portion, fuse caps in liquid . ' If the excess current-in‘ the-line should at thisv ‘ I tight relationship'with' the'ends of the body por- >~ " ' " time drop off and in case the fuse does not "blow,’-’ ' then the droplets will, with normal agitation, re turn to the lower portion of vthe body'and will - again serve to prevent immediate ‘fusing on over load. , ' - " " tion, conducting‘metal' ferrules securing said fuse caps to saidbody poition',.and- a hollow tubular : ' fusible element in electrical association at‘ its ends ' ','with the fuse caps, said fusible element'havingv ’ openings extending-‘through its wall. adjacent to its ends, and a supply of liquid partly ?lling said , * In case the overload drops to a normal operat-_' ing current prior to the time when the heat of ‘body portion .to a‘ prescribed level with respect to the locationyoi one of said openings. _ » ~ '7. In an electric fuse incomblnation, an in vaporization had ‘driven off all the moisture from within the ‘capillary tube, the moisture would then be returned to the lower portion of the fuse/per‘ . sulating tubular bodyportiom-fuse caps-secured. mitting continued service, without interruption. ' ' to and in liquid tight relationship with the’ ends of the body ‘portion ‘and a hollowtubular fusible element in electrical association‘ at its ends‘ with '. Certain changesin relative size and in material" may be made to permit operation atany'given temperature. - . The invention is illustrated in a practical ‘but . I ' simple form of apparatus which, however, may be the fuse caps,.said tubular fusible element having openings extendingthro'ugh its'wall adjacent its . , , - ‘ends, and a‘supply» of liquid partly ?lling said considerably modified so far as details of corn 60 body portion and carried upwardly into said‘tubu lar fusible element by capillary attraction beyond struction ‘are concerned, without departure from its level within said body portion. - ' the principles. of. the invention. Patent .' is: _ _ ‘ _ -' . _ 1. In an electric fuse in combination, an in-' _ sulating tubular body portion, fuse caps secured vclaim as new and desirev to secure by Letters ' . _8..In an- electric fuse in‘ combination, an in'-_ Having thus described our invention, what we ' 65 to the ends of the body portion, ande'a hollow. tubular fusible element in electrical association at - its ends with the fuse caps, said tubular fusible to the ends of the body portion,.and a hollow‘ - element ‘filled with' glass wool ‘and having-open- ~ I ingse'xtending throughits wall adjacent its ends, tubular, fusible element in electrical association sulating'tubular body portion, fuse caps secured at its ends with the fusecaps, said fusible element 70 anda supply of liquid partly fllllngsaid ‘body portion and carried upwardly into said tubular ‘fusible element by a combined‘ action of the ele-. ment surfaoe'and the glass wool surface above -_ having openings extending through its wall adja-v cent to ‘its ends, and a supply of liquid’ partly ?lling said body portion to a prescribed level with respect to the location .of one of said openings. 2. In an electric ‘fuse in combination, an vin _ the level of the liquid within said body portion. _9. In an electric fuse in combination, an'in; . 'A Y e941 moo sole-ting tubular body portion, fuse caps of rela tively high melting temperature secured to the oi the body portion, and a hollow tubular fusible element of relatively low melting temper- _ ature in electrical association at its ends with the fuse caps, said tubular fusible element having openings extending through its wall adjacent its ends, and a supply of liquid partly ?lling said body portion to prescribed level 314th respect to the location of said openings. l0 i=3. Tin an electric fuse in eoiioleination, an ine sulating tubular body portion, rinse caps secured 6 to the ends of the body portion, and a hollow tubular fusible element in electrical association at its ends with the fuse caps, said tubular fusible element having openings extending through its‘ wall adjacent its ends, and a supply of liquid partly ?lling said body portion to a prescribed level with respect to the location of said open ings, said liquid having a boiling point which is below the melting temperature of the fusible element. MELVILIE F. PETERS. JOHN J. PHILLIPS.