US2133139A - Fuse device - Google Patents

Description

Oct. 11, 1938. B. R. HERMA N 7 2,133,139

FUSE DEVICE Filed Nov. 24, 1957 Inventor": 55 Benjamin R. Hermahn,

is Attorney.

Patented on. 11, 1938 PATENT OFFICE FUSE DEVICE Benjamin B. Hermann,

Lancsborough, Man, as-

signonto General Electric Company, a corporation of New York Application November 24, 1937, Serial No. 176,271

12 Claims.

The present invention relates to fuse devices and has for an object the provision of a fuse device of simple and low cost design having improved mounting means particularly suited for installation of the fuse device on, a bushing supported terminal stud of a transformer or like piece of electric apparatus.

A further object of the invention is the provision of a fuse device of improved fuse link tensioning and retracting means and of improved safety means for preventing swinging of a ruptured fuse link into short-circuiting engagement with the live parts of a fuse installation.

Qther objects and the details of that which-I believe to be novel and my invention will become apparent from the'followlng description and the.

claims appended thereto taken in conjunction with the accompanying drawing in which Fig. 1

shows a side-view of an exemplary form of fuse device embodying the present invention; Fig. 2 IS a view looking down on the fuse-device of Fig. 1; Fig. 3 shows the positions of certain parts of the fuse after operation of the fuse link therein;

Fig. 4 is an exploded view of a detail feature of the invention; and Figs. 5 and 6 are views respectively from two different sides of a portion of a fuse device embodying a modification of the in- .vention.

Referring to the drawing, i0 designates a fuse 0 holder of theexpulsion'type which includes an insulating fuse tube open atits lower end and closed at its upper end by means of a removable terminal ,cap ll. Mounted adjacent the upper end of the fuse holder in electrically' conductive relation with cap ll isa metallic collar I2. which and as a mounting bracket for the fuse holder and which includes an intermediate socket portion ll having an opening I! for receiving the 0 lower open end of the fuse holder, the holderbe-' ing secured-in the socket opening in any suitable manner, as by means of a pin i6 which extends through the socket portion into engagement with the side of the fuse holder. Projecting outwardly from one side of the socket portion I4 is a springy mounting arm I! provided'adjacent its outer end with an attachment portion 10 which includes a socket opening 2] for receiving a terminal stud 22 of a transformer or like piece of electric apparatus. As shown in the drawing, the

attachment portion 20 of the arm is adapted to rest upon the upper end of the bushing 23 which supports the terminal stud and to be tightly clamped thereon by means of nut 24. The socket portion I l of the bracket is so arranged that the extended axis of socket opening l5 lies in a plane with and intersects the extended axis of the attachment socket opening it. Thus, fuse holder I0 is maintained in a position wherein its upp portion is tilted toward the supporting terminal stud 22 while'the lower open end of the fuse holder is directed away from the terminal stud and insulator bushing 23. As a result of this expedient, arc gases discharged from fuse holder l0 will be directed away from insulator bushing 23 so. as to prevent damage thereto and also will be directed awayfrom conducting parts of the electric apparatus of which terminal stud 22 forms a part to prevent arc-over between such conducting parts.

The mounting bracket has a second arm 21 which projects outwardly from the socket For-- tlon ll on the opposite side thereof from mounting arm ll. Intermediate the outer end of arm 21 and socket portion I4 is a winged clamping screw 28 for securing tothe arm the outward projecting lower end 28 ofv a fuse link disposed in fuse holder 10, the other end of which fuse link is anchoredin the upper end of the fuse holder and electrically connected with terminal cap II. In order normally to tension the fuse link there is provided a metallic springstrip 30 one end of which is fastened to a collar 3| mounted on fuse holder ill in insulated spaced relation to the socket portion ll of .the terminal mounting bracket and the other end of which spring strip has shock 32 for quick releasable engagement with the outwardly extending portion 29 of the fuse link intermediate the lowerend of the fuse holder and clamp 28. Spring strip 30 is reinforced by spring strlps a and 34 disposed re spectively on opposite sides thereof and the spring strip it normally is bowed, as shown in Fig. l, to tension the fuse link in the fuse holder. Upon rupture of the fuse link due to current overload. the spring strip 30 quickly withdraws the lower portion of the ruptured fuse link from -'the fuse holder to aidin extinction of the are formed between the ruptured ends of the fuse link upon fuse operation. The expulsion force of the gases generatedin the fuse holder upon fuse operation also tends to eject the lower end of the ruptured fuse link from the holder. As will be seen best from Fig. 2. the bowed springstrip, 30 extends "substantially parallel with a vertical plane extending through arm 21. As a result of this expedient and the expulsion force of the gases discharged from the lower end of the fuse holder, the free end of the withdrawn portion of the ruptured fuse link is caused to swing outwardly about clamp 28 and away from the bushing supported terminal stud so as to prevent short-circuiting engagement of the free end of the withdrawn portion with conducting parts of the electric apparatus of which terminal stud 22 forms a part. In order to prevent swinging of the free end of the withdrawn portion of the fuse link upwardly into short-circuiting engagement with the terminal collar l2, terminal arm l3, or other live parts at the upper end of in Fig. 3, and the outwardly projecting spaced arms 31 of the snubbing element insure against the escaping sideways of the withdrawn fuse link portion from the snubbing element. With the arrangement described, the distance from the snubbing element, which projects outwardly beyond clamp 28, is greater than the length of the withdrawn portion of the fuse link even though the fuse link ruptures at a point adjacent the upper end of the fuse holder. Also, as the withdrawn fuse link portion wraps around the snub-' bing element, it becomes disengaged from the hook 32 of spring strip 30 and the spring strip is then electrically isolated from all conducting parts of the fuse device and extends outwardly, as indicated in Fig. 3, to. give clear indication of fuse operation. The electric isolation of the spring strip from the lower terminal member insures against arcing to the spring strip or to hook 32 during ejection of a ruptured fuse link so that the spring strip is not called upon to carry heavy currents which might cause the spring strip to lose its springiness.

It is desirable to provide for selective positioning of the fuse device on the supporting terminal stud 22 and at the same time to insure against movement of the fuse device out of the selected position. To this end the attachment portion 20 of arm I! is provided with a plurality of slots 40 which communicate with and extend radially of the socket opening 2 I. These slots are arranged in pairs with the slots of each pair disposed diametrically opposite each other and with the pairs angularly spaced apart. When the mounting bracket is mounted on the supporting terminal stud 22, it is turned into a desired position wherein a predetermined one of the pairs of slots 4!! register with a transverse slot 4| in the terminal stud. Then, in order to maintain this selected position, a keeper element 42 is placed in the selected pair of slots 40 and the transverse slot 4|. This keeper element is of approximately U-shape having a transverse portion 43 adapted to seat in slot 4| with the outer ends of I this transverse portion extending into diametrically opposite slots 40, and having also spaced apart arms 44 bent inwardly and then upwardly, as shown in Fig. 4, to be receivedin the bore of nut 24. The arms 44 may be inserted in the bore of the nut and the upper ends of the arms bent outwardly so as to make the keeper a part of the nut assembly. With the arrangement illustrated, wherein two pairs of slots 40 are provided, the mounting bracket may be supported on terminal stud 22 in anyone of four different positions angularly displaced 90 apart, two of these positions being indicated respectively in solid and broken lines in Fig. 2. It will be understood of course that more than two pairs of slots 40 may be employed if it is desired to provide for more than four possible positions.

In Figs. 5 and 6 is illustrated an embodiment of the spring retracting and snubbing feature of my invention which is particularly adapted for use with line suspension type fuse cutouts. In this latter embodiment, there is mounted on the lower end of the fuse holder Ill a metallic terminal collar d5 which has projecting outwardly from one side thereof an arm 46 provided with any suitable form of clamping means, indicated at M, for securing a line connection lead 48 thereto. Projecting outwardly from the opposite side of terminal collar 45 isan arm 50 provided with a winged clamp screw 5! for anchoring thereto the outwardly extending portion 29 of a fuse link, the other end of which fuse link is connected with a terminal cap, as previously described in connection with the embodiment -of Figs. 1 to 3. Also mounted on'the lower end of fuse holder ill, but in insulated spaced relation to terminal collar 45 is a second collar 52 which has an arm 53 projecting outwardly and downwardly therefrom so that the outer end of the arm is disposed to the side of and below the lower end of the fuse holder, as shown in Fig. 5.

a coiled spring strip 55. The other end of spring "wardly, it'engages the transversely extending portion 54 of arm 53, and is snubbed'by this portion 54 so that the free end of the withdrawn fuse link portion is prevented from swinging upwardly about clamp 5| into short-circuiting engagement with live parts at the upper end of the fuse holder. 'Also, as in the embodiment of Figs. 1 to 3, the withdrawn fuse link portion becomes disengaged from hook 56 as it swings outwardly so that spring strip is then electrically isolated from all conductive parts of the fuse device and the spring strip projects outwardly to give a clear indication of fuse link operation.

It will be evident that my invention is -not limited to the specific details of the embodiments illustrated and that various modifications well within the range of mechanical skill may be made to adapt the invention to various conditions met with in actual practice.

modifications as fall within the true spirit and scope of my present invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. In a fuse device, the combination with a fuse holder of the expulsion type havingan open Hence, it is intended to cover by the appended claims such end for, the discharge of gases therefrom, of an electrically conductive bracket for mounting said holder on a terminal stud of a transformer or like support, said bracket having a socket for receiving said holder and having also a relatively springy arm extending outwardly from said holder with a second socket adjacent the outer end of the arm for receiving a supporting terminal stud, said first socket being arranged so as to support said holder tilted substantially toward the outer end of said arm with the said discharge end of the holder directed away from said outer end of the arm.

2. In a fuse device, the combination with a fuse holder of the expulsion type having an open end for the discharge of gases'therefrom, of means for mounting said holder on a terminal stud having a transverse slot, said means including an electrically conductive bracket having a socket opening adapted to receive a slotted terminal stud, said bracket being provided also with a plurality of slots communicating with and extending radially of said socket opening'in angularly spaced relationship to each other, and a keeper element adapted to be placed in selected ones of said slots andto extend through a transverse slot in a terminal stud upon which said bracket is mounted in order to maintain said bracket in selected positions and prevent rotation of the bracket about the supportingterminal stud.

3. In a fuse device, a fuse holder having a gas discharge opening at one end, an electrically conductive mounting bracket secured to said holder and having an outwardly projecting arm with means adjacent the outer end thereof for attachment to a support for said holder, said bracket being arranged to support said'holder with the said gas disbhargeend thereof directed away from the attachment end of said arm, clamping means for securing to said bracket one end of a fuse link extending .out of said one end of the holder, and a spring device arranged to be connected with a fuse link in said holder for normally tensioning the fuse link, said spring device being operative upon fuse link rupture quickly to withdraw a portion of the ruptured manner to cause the withdrawn fuse link portion to swing away from the said outer attachment end of said arm.

4. In a fuse device, a fuse holder, .an electrically conductive mounting bracket secured to said holder adjacent one end thereof, means for securing to said bracket one end of a fuse link extending from said one end of the fuse holder,

said bracket having a pair of arms projecting outwardly respectively in different directions from said fuseholder and one of said arms having means for attachment thereof to a support for said fuse holder, a spring device arranged to be connected with the end of a fuse link extending from said one end of the fuse holder for effecting quick withdrawal of a portion of the fuse anchored tov the other of said terminals, fuse link tensioning and retracting spring means connected with said other end of the fuse link and operative upon fuse link rupture to eifect quick withdrawal of a portion of the fuse link in a manner to cause said withdrawn portion to swing about its anchoring point on said other terminal, and snubbing means arranged to intercept, the said withdrawn fuse link portion to-prevent swinging of the free end thereof into proximity with said one terminal. i

6. A fuse device including in combination an expulsion fuse holder having an open end for the discharge of gases therefrom, terminals adjacent opposite ends of the holder, a fuse link in said holder connected between said terminals with one end of the fuse link anchored to the one of said terminals adjacent said open end of the holder, a portionof said fuse link upon fuse link rupture being expelled from said open end of the holder in a manner to cause the expelled fuse link portion to swing about its anchoring point on said one terminal, and snubbing means -inend thereof into proximity with the other of said terminals.

7. In a fuse device including a fuse holder adapted to accommodate therein a fuse link and having adjacent one end thereof a terminal with means for securing thereto one end of a fuse link in said holder, a fuse link tensioning and retracting spring device arranged to be connected with a fuse link accommodated in said holder for effecting upon rupture of the fuse link a quick withdrawal of a freed end of the fuse link from the holder in a manner to cause such withdrawn end of the fuse link to swing about said securing means, and an arm projecting outwardly from said holder and provided at its outer end with a transversely extending portion arranged to extend into the path of swinging of the withdrawn fuse link end to intercept the same and prevent swinging thereof into proximity with the other end of said holder.

8. In a fuse device, a fuse holder open at one end and having a terminal adjacent the other end thereof, a conducting member secured to the fuse holder adjacent said open end thereof and having an arm projecting outwardly from said holder, a. fuse link in the holder with one end connected to said terminal and the other end extending out of said open end of the holder,

, means clamping said other end of the fuse link to said member intermediate the outer end of said arm and said open end of the holder, a spring device connected with said fuse link intermediate said clamping means and said open end of the holder and operative upon fuse link rupture quickly to withdraw. the fuse link from the holder in a manner to cause the withdrawn fuse link to swing about said clamping means in'the direction of the outer end of said arm, and snubbing means on the outer end of said arm arranged to intercept the withdrawn fuse link to prevent the free end thereof from swinging into proximity with the terminal at said other end of the fuse holder.

9. In a fuse device, a fuse holder having a terminal at one end thereof, a fuse link in saidholder with one end connected with said terminal and the other end thereof extending out the other end of said holder, a member secured to said holder and having an armprojecting outwardlyfrom the holder adjacent said other end of the holder, terminal means adjacent said other end of the holder including a clamp for anchoring said outwardly extending end of the fuse link'at a point intermediate the outer end of said arm and said other end of the holder, and a spring device arranged normally to tension said fuse link and operative upon fuse link rupture to withdraw the fuse link from said holder in a manner to cause swinging of the withdrawn fuse link about said clamp and towardsaid arm, said arm having a portion arranged to extend transversely of the pail i 05. swinging of the withdrawn'fuse link at a point from said clamp so as to intercept the ndrarni link.

10. In a fuse device, accommodate therein a fuse link, a member mounted on said holder-and having an arm projecting outwardly mm. the holder adjment one end of the holder, terminal means including a clamp for anchoring intermediate said one end of the holder and the outer end of said arm one end of a fuse link extending from said one end from said holder in a manner to cause swinging of the withdrawn fuse link about said clamp and Patent No. 2,155,159;

a fuse holder adapted toe link a quick withdrawal of the fuse link BENJAMIN R HERNA NN toward the outer end of said arm, said arm having a portion arranged to extend transversely of the path of swinging of the withdrawn fuse link for intercepting the same.

11. In a fuse device including a fuse holder adapted to accommodate therein a fuse link and having adjacent one end thereof a terminal with means for seeming thereto one end of a fuse link extending from said one end of the holder, a fuse link tensioning and retracting spring carried by said holder in spaced apart electrically insulated relationship with said terminal and having means arranged releasably to engage a fuse link ,at a point intermediate said securing means and said one end of the fuse holder.

12. In a fuse device including a fuse holder adapted to accommodate therein a fuse link and having mounted adjacent one end thereof a terminal with means for securlng thereto one end of a fuse link extending from said one end of. the holder, a fuse link tensioning and retracting spring strip, a supporting element for said spring strip clamped to said holder in spaced apart electrically insulated relationship with said terminal, means for securing one end of said spring strip to said supporting element, and a hook on the other end of said spring strip for quick releasable engagement with a portion of a fuse link extendlng out of said one end of the fuse holder.

BENJAMIN R. HERIMNN.

October 11, 1958'.

It is hereby certified that error appears in the .printed specification of the above numbered patent requiring correction as follows Page 5',

first column, line L T, claim5, after the. word "ruptured" insert fuse link from said one end of the holder in a; and that the said Letters Patent should be read with this correction, therein that the same may conform to the record of the case in the Patent Office Signed and sealed this 15th day of December, k. D. 1958.

. Seal) Henrv Van Arsdale Acting Commissioner of Patents.

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