US1700080A

US1700080A - Fuse

Info

Publication number: US1700080A
Application number: US477681A
Authority: US
Inventors: Sandin Jerome
Original assignee: Westinghouse Electric and Manufacturing Co
Current assignee: CBS Corp
Priority date: 1921-06-15
Filing date: 1921-06-15
Publication date: 1929-01-22
Anticipated expiration: 1946-01-22

Description

Elank 229 1929. 1,700,080

.sANDwi FUE E Original Flec. une l5 1921 t A, I e

'f-f. l' l l.

ATTORNEY T' 0,6. i q. l i922@ agree/f .1 i. ,a am n il i My invention relates to fuses and particularly to refillable cartridge fuses.

@ne object of my invention is to provide a reillalole and renewable fuse mechanism wherein the contact surfaces which clamp the fuse ends are prevented from becoming oii dized by reason of repeated fuse blowings.

Another object of my invention is to provide a fuse mechanism having vented fusesupporting members wherein the fuse member supported thereby is prevented from accidently covering the vent and interfering` with the proper escape of the gases.

Another object of the invention is to provide a fuseesupporting element having the alcove characteristics that may be manufactured as cheaply as elements now employed and that may be applied to standard fuses without necessitating changes therein.

rlh'ese and other objects, that will be made apparent throughout the further description of the invention, are attained by means of the apparatus hereinafter described and illustrated in the accompanying drawings, wherein:

Figure 1 is a longitudinal section through a fuse embodying my invention;

Figs. 2 and 3 are perspective views of the clamping disc and the supporting disc, respectively, shown in Fig. 1; f

Fig. 4 is a front elevation of the closure or cap member, shown in Fig. 1

Fig. 5 is a perspectivel view of the fuse shown in Fie'. 1;

Fig. 6 is a side elevation of the modified form of fuse, showing one end thereof in longitudinal section;

Fig. 7 is a perspective view of a modified 3, form of fuse-supporting disc shown in Fig.

8; and

Fig. 8 is a side elevation of another modied form of fuse, showing one end in longitudinal section.

In my co-pending application, Serial No. 308,686, filed July 5, 1919, I have disclosed a fuse construction having vented fuse-supporting discs and vented clamping discs between which the terminals of a fusible element are clamped. The gases of combustion resulting from the rupture of the fusible, element escape from the casing through the vents in the supporting discs and pass through the space between the supportingl discs and the clamping discs to the atmosphere rio. s'f'i. Renewed .Tune 25j,

""il/v hen a fuse blows, the adjacent surfaces which are unprotected by the yfuse element become coated .with particles of the blown fuse, and when a fnse element is renewed, the ends thereof do not cover 'the enact place occupied by the rmer fuse element, and, therefore, parts of the coated adjacent surfaces clamp the fuse ends and tend to keep the contact surfaces previously covered and protected by the blown fuse away from the fuse ends. Because of this condition, two or three blowings of the fuse elements results in the contact surfaces, becoming entirely coated with oxides, solder and foreign substances which prevent a good conductive contact of the fuse element with the clamping members. f As the vents of the clamping disc generally consist-of a plurality of small perforations of 'a definite size and number, depending upon the capaeityof the fuse and the inten sity of the explosion, it is necessary that all should function in order that t-he gases may be discharged atproper velocity to prevent bursting of the fuse casing and to ensure proper pressure, as determined, by test, to be necessary to quickly extinguish the arc incident to the explosion.

As heretofore constructed, clamping discs have been provided with flat surfaces, and it frequently occurs that the flat terminal of Y the fuse covers one or more of theperforations or vents and prevents proper escape of the gases. Under such conditions, the pressure within the fuse is liable to cause the casing to burst.

The conditions above-referred-to are entirely eliminated by my invention, which' consists, primarily, in providing ,the clamping disc or member with a clamping seat that is spacedifrom the main vented cooling surface of the member and which supports the fuse terminal in spaced relation with respect to the said surface. The fuse terminal cannot, under any condition, close the vents.

The greatest dimension of the clamping seat is smaller than the minimum dimension of the fuse terminal and, therefore, is completely covered by the terminalwhich protects the seat from contact withthe gases of combustion and the fusible metal carried thereby.

When a blown fuse is removed, the clamping surface is clean and ready for proper conductive contact with the new fuse. The

supporting discs may also be provided with a similar raised or embossed clamping surface.

Referring to the drawings and particularly to' Figs. land 4, the fuse mechanism lincludes an insulating cylindrical shell or I or cap member 13 is screwed upon the ferrule 11 and serves to close the ends of tli/e casing. Each cap 13 is provided with a countersunk chamber 14, in which a disc 15, preferably made of fullerboard, is loosely disposed, which serves as a baffle for directing the gases, resulting from the blowing of va fuse, to the outer ends of a plurality of radially disposed grooves 1G that are provided in the bottom of the countersunk chamber 14 and which lead from the edge of the chamber toa central orifice 17.

The fusible member 18, illustrated in Figs. 1 and 5, comprises a flat strip made of readily fusible metal and is cut away at its edges so as to provide relatively narrow sections 19 for'v the purpose of localizing the point of Arupture of the fuse. The, fusible member 18 is supported within the casing by means of supporting or centering discs 21 that are provided, on one side, with a plurality of lugs 22 distributed about the center of the disc at equal distances therefrom. vThe lugs 22 fit in the ends of the ferrules 11 and serve to center the dise with respect to the easing. f

The disc is cutv awayat one side, as at 23, for the purpose of providingthe vent 24,

' through which the fiat end or terminal 25 of the fusible member 18 extends. The fusible members are usually furnished in flat strips, and the ends or terminals thereof are bent at substantially right angles to the body of the fuse, as illustrated in Fig. 1.

As shown in Figs. 1 and 3, the supporting` dise 21 is provided with a circular clamping face 26 having a fuse-engaging surface of less diameter than the minimum width of the terminal 25. The surface 26 is spaced a short distance from theniain surface of the disc surface and supports the fuse out of contact therewith.

The fuse is clamped to the supporting disc 21 by means of a clamping dise 27 that is carried by the cap 13 and is rotatable with respect thereto. The disc 27 is provided With a similar clamping face 28, the plane of which is spaced from the main surface 29 of the discL The least dimension of the clamping surface 28, like that of the disc 21, is less than the minimum dimension of the terminal 25 and, therefore, when the surface 28 is in operative engagement with the fuse 18, the operative engaging surface is entirely covered by the fuse terminal 25 and is protected from gases entering the cooling chamber between the supporting disc 21 and the clamping disc 27 through the vent 24.

The clamping disc 27 is provided with a plurality of perforations 31 that are equally spaced about the circular clamping seat 28. rllhe number and size of these perforations is determined by the capacity of the fuse and the intensity of the explosion thereof, the purpose being to permit the escape of gas at a velocity that will prevent the explosion of the casing and, at the same time, maintain the pressure within the casing necessary to instantaneously extinguish thc arc. f

rlhe perforations 31 are so positioned that they discharge into the counter-sunk chamber 14. rlhe gases escaping from the perforations in the clamping dise 27 force the movable disc l5 against the bottom of the countersunk chamber 14 and are directed thereby through the grooves 16 to the discharge opening 17. f

lt will be seen from the foregoing that, regardless of the length of the terminal 25, the perforations 31 cannot be covered thereby under any condition. Because the clamping seats of the supporting disc 21 and the clamping discv 27 are completely covered by the fuse terminals, they are protected from the gases passing between the said discs, and consequently, are free from the usual deposits of fuse metal and the gases of combustion. It will be understood that the clamping seats are tightly drawn into contact with the fusible element and, therefore, the gases cannot creep between the fuse surface and the seats.

When a new fuse is inserted between the clamping surfaces, a proper conductive contact is secured. The surfaces are maintained in clean condition regardless of repeated explosions and do not require cleaning before the insertion of a new fuse. I

Referring to Fig. 6, a modified form of closure construction is illustrated, wherein the cap or closure member 32 is provided with a. clamping seat 33 that is spaced from the main interior face 34 of the cap. The easing 37, the ferrule 38 and the supporting disc 39 are similaiin every respect to like parts illustrated in Fig. 1, the difference in the fuse construction residing in the elimination ofthe vent Within the cap and the fullerboard dise. In this construction, the gases escape between the threads of the capiand ferrule.

Referring to Fig. 8, a modified form of ferrule and closure is illustrated, wherein the ferrule 41, that is secured to the casing 42, is internally threaded for receiving the clamping disc 43. The dise is provided with a clamping face 44 that is spaced from the main internal face 45 of the disc. The gases of combustion escape from the cooling charner eicls oi between I e l isc i8 is of modified construction and ucted as illustratV g. The provided with ce l race that is spaced from the surface 5i of the disc for the purpievicusly specified. This disc, howis provided with slet 52 that is cut edge thereof for the purpose of the fuse 53. The slot is of greater ian the thickness of the fuse and, con- 'equentiy, permits the gases of combustion within the fuse chamber 5- to escape from 'ruse chamber f7 'through the slot. rflic disc is centered within the ferrule lll..

it will be observed that the clamping surfaces in the modified constructions shown in TFigs. 6 and 8, will be maintained in clean condition in the manner described in connection with the fuse illustrated in ig'. i.. lt is also apparent that the fuse, in the end vented enclosures, can, at no time, close the vents or obstruct the escape of gases there from.

While ll have described and illustrated but three embodiments of my invention, it will be apparent to those skilled in the art that various changes, modifications, substi tutions, additions and omissions may be made in the apparatus illustrated without departing from the spirit and scope of the invention, as set forth in the appended claims.

ll claim as my invention ':-v

l. lln a renewable fuse, a. casing, a fusible element, and a supporting structure for the fusible element including a pair of members each having a vented surface exposed to the gases of combustion and provided. with a clamping lseat spaced from the said surface and engaging the said fusible member.

2. ln a renewable fuse, a. fusible member, a pair `of vented members for supporting` the fusible member with a portion thereof between them and having transverse gas-cooling surfaces and means for holding the fusible element in longitudinally spaced relation with respect to each of the said surfaces.

3. lln a renewable fuse, a fusible member having a terminal, and a pair of vertical members for supporting the said terminal between them and each having a p asecoolw ing surface and clamping face spaced om the gas-cooling rface thereof for engagmg p romembers for clamping a fuse element be` tween them and providing a passage therebetween, each of the said members beprovided with centrally disposed seat of less-diameter than the width of the fuse element, for supporting the fuse element in spaced relation with adjacent surfaces of the said members.

in fuse, a casing, a fusible member, a vented supporting member and a vented closure member for the casing, said supporting` and closure members each being provided with centrally raised clamping surface for engaging the fusible member and for clamping it between the closure member and the supporting member.

6. ln a fuse, a casing, a fusible member, a vented supporting member carried by the casing` and a closure member for the casing, said supporting and closure members each having a centrally disposed, flat, raised clamping seat engaging the fusible member and of less diameter than the width of the fusible member.

7. ln a fuse, a fusible member, a casing member therefor, a pair of members c0- operating with the casing member to provide a chamber structure having longitudinally spaced, transversely extending, metallic, gas-cooling surfaces in the casing, and means for clamping a portion of said fusible member in longitudinally spaced relation to one of said cooling surfaces and preventing the impingement of gases against the clamping surfaces of the clamping means.

8. ln a cartridge fuse, a detachable end cap, in combination with a washer carried thereby on its inner face, and a rigid circular boss on the inner face of the washer for male ing Contact with the end of the fuse strip.

In testimony whereof, l have hereunto subscribed my name this 2nd day of J une, 1921.

JEROME SANDIN.

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