US1569981A - Expulsion-type repeating fuse - Google Patents

Description

Jan. 1.9 1926.

T. F. JOHNSON, JR

EXPULSION TYPE REPEATING FUSE Filed Augusi 12, 1922 2 Sheets-Sheet l INVENTOR A'rroRNEY y I y Jan. 19 1926.

- 1,569,981 T. F. JOHNSON, JR

EXPULSION/ TYPE REPEATING FUSE INVENTOR APatented dan, i9, 1926, y

l iT

carica,

TGMLINSON FQRT JOHNSUN, JR., @E ATLANTA, GEUBLGM.

. EXPULSON-TYPE REPEATEN@ FUSE;

Application filed August 12, i922. Serial to. 581,453.

and State of Georgia, have invented new and useful improvements in Expulsionrlype Repeating Fuses, of which the following is a specilication. y Y

This invention relates to improvements in fuses, particularly fuses of the expulsion type.

Primarily, fuses are employed Jfor the purpose of opening the circuits of electrical apparatus when the apparatus is subjected to a heavy overload or to the destructive effects of a short circuit. Fuses, however, will blow or explode whenever there is a temporary rush or surge of current, which occurs most frequently during thunderstorms butV may occur in the course ot' the normal maintenance of a high voltage power line, and when there is nothing the matter with the apparatus. It every time a fuse p blew, there was trouble in the apparatus e. g. a short circuit, there would be no necessity for anything `but a single fuse since the trouble would have to be corrected be- `fore renewing the fuse. However, in the great majority of instances when a fus-e blows there is nothing the matter with the apparatus and this is especially true in the case of high voltage long distancetransmission lines. lf single fuses are used to protect apparatus, for example a transformer, connected with aI high voltage line, a temporary rush ofA current of suicient energy to blow the fuse will incapacitate the service lines leading from the trans.

former, resulting in considerable delay be. fore service Jis restored with consequent annoyance to customers, and in considerable expense and loss in revenue to the company selling the current..

By the present invention, l' provide a novel form of fuse which may be called ar repeating fuse, because after` the 'fuse originally in circuit is blown, the apparatus following a predeterminable time interval automatically puts a second fuse in circuit; and if desired, after the second fuse has exploded, a third or any greater number of fuses may be successively cutin to restore service automatically and yet protect the apparatus. Thus the operating expenses are reduced, the loss in revenue due to incapacitated service lines is nearly eliminated, and generally a much more satisiactoryyV service is given current consumers.

A further advantage of the present 1n'- vention is that the particularfuse or fuses blown arefindicated by the position of the mechanism, so that the inspectors who patrol the transmission system can see at a glance the condition of the apparatus and can renew the fuses before the vlast .fuse blows, which, if allowed to occur, would interrupt service The invention has other aims and advantages which will appear in the following description of one preferred and illustrative embodiment thereof.

ln the drawings accompanyingand forming a part or" this specification, f

ldigure l is an elevation of one form of apparatus illustrating the advantages of the invention; l i Figure is a. fragmentary elevation of the same, on an enlarged scale, and showing the positions of parts when one fuse has blown; and

Figure 3 is a vertical section on the line 3 3 of Figure l.

Figures 4 and 5 are details representing a modification disclosing the use of a dash pot. Y

.Referring more specically to the drawing, there is shown by way of illustration, and not of limitation, a base or support 5 which l'may conveniently be a channel iron xed upon a tower, polev or other structure (not shown) and disposed horizontally. Upon the channel iron 5 may be secured castings 6 for holding wooden pins 7 upon which are screwed porcelain insulators 8 o any appropriate design. The upper ends of insulators 8 areehown as mounting cast iron caps 9. The yparts so far described provlde a convenient form of rigid insulating l ,support for the apparatus which embodies my 1nvention.

Secured to or integral with the cast iron caps 9 are vertically extending fuse sup-` ports 10, preferably castings, and disposed a suitable distance from each other to inhibit any possible arcing. The'fuse sunports 10 are shaped so as to hold between them preferably in a horizontal position one or more fuses 11, which may be of any Well known type, but are'shown as comprising hollow i porcelain tubes through each or which a fusible strip or" metal 12 is assed. The left hand fuse support `10 or enample) is connected to the transmission line by a lug 13 soldered or otherwise secured to cap 9; and the incoming line conductor 14 ismade fast to the lug 13. The left hand ends of the fusible elements 12, said ends being indicated at 12a, 12"D and 12C, are joined to the adjacent casting 10 sov that current from conductor llmay pass to one or another of the uses.`

, details At the right hand end f the luppermost fuse 11 there is a metallic cap 15 electrically connected both to the fusible element 12 and to' the right hand fuse support 10, the latter connection being by m'eanso a conductor or bond 16, for example. The lower end ofsaid fuse support is joined by a lug 17 and conductor 13 to anytelectrical apparatus which it is desired to protect. The current normally `iows from conductor 14 -to the left hand fuse support'lO, through 12 and 12, cap 15, bond 16, right hand fuse support ,10 and out through lug 1T and conductor 18. In short, all the fuses except the uppermost fuse are normally out of circuit.

When the upper fuse blows due to a dangerous surgeof current in the power line, my apparatus automatically acts to put the next lower fuse in circuit, but preferably only after a suitable .Y time interval has elapsed. \As most clearly shown in Figure 2, the cap 15 swingingly supports a lever 19,

as, by a pivot and a pairV of depending' arms 21 between which the lever may swing. At an intermediate point, the lever 19 is mechanically joined as atl 22 to the projecting end of fusible element 12, as seen in lFigure 1, so that normally the leverv 19 is held in a tilted position, `with the outer end higher than the end adjacent pivot 20. When the fusible element blows or explodes in the" confined spacev of porcelain tube 11, the lever 19 will no longerhavea support for its outer end. and will vtend to` move ,down-Y wardly into the position of Figure`2, where its outer'end 23 isshown making'contactl with a pair 'of spring jaws 2st;L The jaws 24 'are enerally similar to those employed with 25 in turn supported on the intermediate fuse 11 4and connected to the fusible element thereof. i n

- lit will be readilyunderstood that when the upper fuse yis blown, and lever 19 falls to make contactwith jaws 24, the current Hows from the left fuse support 10 through connection 12b and element 12, through cap 25 and lever 19, arms 21, cap 15, bond 16, fuse support 10, `and out through conductor 8 'with the jaws 24. rl`he weight 26 has' another use as will be described later.

` YWhile the parts so far describedV form an operative repeating fuse, it is preferred that some means be employed to prevent the cutting in of the second fuse at once, so that some time is allowed for normal conditions l to be restored in the transmission line. In

order to retard theclosing of switch 19, a bendable strip of lead or similar metal 28 is interposed between the short end of switch 19 and the cap 15, preferably being attached at each end by screws or the like to legs 21 and switch 19. v

There is a lever 29.pivoted on element 20 to swing alongside switch 19 and one end of lever 29 is connected to a coil spring 30, whose other end is xed to cap 15. The lever 29 has an arcuate slot 31 in which a pin or projection 32 on switch 19 may slide when lever 29 is swung. 0n theslotted part of lever 29 a flat surface 33 is rovided, and

a screw 34 borne on cap 15 1s adapted to i bear against the flat surface 33 to adjust the angular position of lever 29. The lever 29 is really avbell crank lever, and,the` arm thereof connected to spring v is in a substantially vertical position when the screw 34- comes in contact with surface 33. `At

this timeuthe spring 30 is also vertical and its line of force passes through the pivot 20 whereby said spring ,is ina dead center pos sition. The screw 3stv provides means whereby the lever is prevented from moving past the dead center position when swung in a counterclockwise position, and also provides means for eecting a nice-,adjustment of the position oflever 29- Then the fuse blows the weight 26 on switch 19 causes its outer end to descend at a relatively slow rate, whereupon the pin f j .or projection 32engages the lower end of km e'switches and are carried upon a cap\ in a clockwise direction to bring the upper end of the slot into engagement with p1n incassi.

.,32. rllhen the force of the spring 30 is blowing of one fuse andclosing of the circuit due to cutting in of the adjacent fuse may be made whatever is desired.

l'nstead of the lead strip other braking elements or mechanism may be employed, :for example al dash-pot. Tins 1s shown 1n Figures and a.

lt will ybe clear that by properly proportioning the switch arms 19, 19, etc., the weights 26, 26a, the strips of lead 28, 28a, and the springs 30, 30, the actionof the apparatus may be made either very slow, or relatively fast, though it will never operate simultaneously and hence there will al ways be a -time interval between the blowing of one fuse and the restoring of service. lUpon the intermediate fuse the cap 25 is secured as has already been described;

.and associated with said cap is a switch and switch operating mechanism exactly like `the one previously described. The corresponding parts of the secondswitch mechamsm are designated by the letter a added to QlLCll reference, numeral.

of switch 19.8.

When the second fuse blows, the switch 191 descends toward a cap mounted on the end Vof' thelowest fuse and connected to 'fusible element 12 as shown. 'lhe cap 35 mounts a pair of spring jaws 36 adapted to receive between them the outer end 23a Ubviously after the second fuse has blown, the current from conc ductor 14 `passes through the third fuse,

vce

through both switches 19a and 19, and so outl through conductor 18.

The apparatus-.enables an inspector to ytell at a glance the condition of. the `luses.

With the parts as shown' in Figure 1, all the fuses are ready for any emergency; when the apparatus'presents the' appearance of Figure 2, the uppermost Jfuse needs re` holds lever 19Pin position., When the fuses melts, the lever 19a drops down until. pin M restson lower. lipof' part H. The latter is pulled slowly tov'vard the dash'pot by means of the coiled spring S located inside of dash pot until p inM falls odv the endet lower lip of part I-ll. An interval of about ten seconds elapses l between the melting of the frise and the release of pin M from part lia,

The present invention provides a novel form oli apparatus particularly well adapted for outdoor worlz, large current and high voltages. 'llhe parts will operate perfectw' in all` weather. 'llhe construction is rugged and simple and unlikely to get-out of order. My repeatin fuse protects the apparatus by cutting o the How of current completely for a determinable time interval, and there automatically reestablishing the service;

and this cutting 0E and reestablishment process may be repeated as often as desirede l/Vhile ll have described in some detail` one illustrative embodiment o Imy inven tion, it `"will be understood that many changes involving omission, alteration, suhstitution andreversal of parts may be made without departing from the invention, which is best defined in the following claims.,

Vi/'hat is claimed is 1. Repeating fuse apparatus comprising a pair of fuses, a gravity operated switch tween said fuses normally'held in inactive position by the fuse which is connected in circuit, means for retarding the initial. movement of the switch after the first fuse is blown, and means. to accelerate the final. movement of the switch to connect the second fuse in circuit.

2. Repeating fuse apparatus comprising a pair of spaced approximately vertical supports, a pair of usescarried by said supports` and arranged approximately horizon tally one below the other, the upper fuse be ing connected in circuit, a gravity actuated switch 4element normally supported in inactive position by the fusible portion of said upper fuse and adapted to be released automaltically to close` the circuitthrough the lower fuse when the upper fuse blows, and means to regulate thetime interval during which said switch closes.

3. Repeating fuse apparatus comprising.

a pair of fuses arranged one above the other, each connected at one terminal to a leading-in wire, and the upper fuse normally connected in circuit, a gravity actuated switch arm normally held inactive by the fusible element inthe upper fuse and adapted to be released to close the circuit 'to close the circuit through the next fuse,

and an easily bendable stri ot metal connected to sa1d arm to. retar lts movement. 5. Repeatlng fuse apparatus comprising a pair of fusesI one of which `is normally in circuit, and a switch member connected mechanically with the fusible part of the fuse normally in circuit, means tending to move said switch toward the other fuse and operable when the first fuse blows, a contact on the second fuse with which said switch is engaged following blowing of the first fuse, whereby the second fuse is put in circuit, and means for operating the switch first slowly and then more rapidly so that a good contact is made with the contact part of the second fuse.

`6. Repeating fuse apparatus comprising a pair of fuses one of which is normally in circuit, and a switchand operating mechanism therefor adapted to put the second fuse in circuit when the first fuseblows, said mechanism operating to cause a slow movement of the switch toward circuit closing position followed by a quicker movement, and means whereby the earlier slower movement of the switch may be varied so as to increase or decrease the time interval during which the circuit remains broken.

7 Repeating fuse apparatus comprising a pair of fuses one of which is normally in circuit, a switch swingingly mounted between said fuses, adjustable means for causing said switch to move toward a position to put the second fuse in circuit when the first fuse blows, and means operable after.

a certain movement of the switch to cause the switch to close with more force and at a greater speed.

8. Repeating fuse apparatus comprising a pair of fuses one of which is normally in circuit, a switch swingingly mounted between said fuses, adjustable means for causing said switch to move towarda position to put the second fuse in circuit when the first fuse blows, means operable after a certain movement of the switch to cause the switch to close with more force and at a greater speed, said second named means b eing inoperative in the normal positions of the parts, and means for adjusting the sensitiveness of operation of the second named means. .f

9. Repeating fuse apparatus comprising a pair of fuses one of which is normally in circuit, a switch swingingly mounted between said fuses, adjustable means for causing said switch to move toward a position to put the second fuselin circuit when the first; fusei blows, means operable after a certain movement of the swltch to cause the switch to close with moreA force and at a greater speed, said second named means operating wholly independently of the first named means but being put into action wholly by movement of the switch, and adding its force to the force of the first named means to' cause the switch to close.

10. Repeating fuse apparatus comprising .Maasai movement of the switch to cause the switchto close with vmore force and at a greater speed, said second named means operatin wholly independently of thev first name means but being put into action wholly by movement of the switch, and adding its force to the force of the first named means "to cause the switch to close, and means for adjusting the position of parts of the second named means to effect changes in sensitiveness of operation thereof.

1l. Repeating fuse apparatus comprising a pair of fuses one of which isl normally in circuit, a switch mounted tomove toward the other fuse, means connecting the switch and fusible part of the first fuse for holding the switch normally spaced 'from the second fuse, means for braking the tendency of the switch to move toward the second fuse, and adjustable means acting to increase the tendency of the switch to move-as aforesaid, the apparatus functioning when the fuse normally in circuit blows to put-the second fuse in circuit after a determinable time interval.

12. Repeating fuse apparatus comprising a pair of fusesl one of which is normally in circuit, a switch mounted to move toward a pair of fuses one of w ich is normally in.

circuit, a switch swingingly mounted between said fuses, a contact member on the second fuse with which the switch is designed to engage, the switch being so mounted as to have a tendency to move toward the contact member but being engaged bylthe fusible elementof the first fuse so that it is held normally spaced from the contact, a spring-actuated delayed-action mechanism rendered normally inoperative by being in a dead center position when the switch 1s open, and connections between the switch and mechanism whereby it is moved past dead center and thereupon becomes active 'to force the switch against the contact, whereby the second fuse is put in circuit.

14. Repeating fuse apparatus comprising I a pair of fuses one of which is normally in circuit, a switch swingingly mounted between said fuses, a contact member on the second fuse with which the switch is designed to engage, means connected with the switch for imparting thereto a tendency to close toward the contact member, said latter means being adjustable, a spring-actuated delayed-action mechanism rendered nor- 3 mallyinoperative by being in a dead center a position when the switch is open, and connections between the switch and said mech-- anism whereby it is moved ast dead center and thereupon becomes actlve to force the switch against the contact, whereby the second fuse is put in circuit.

In testimony that claim the foregoing as my own, have hereto'atiixed my -signature.

ToMLNsoN FORT JOHNSON, Jn.

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