US1164320A - Circuit-breaker. - Google Patents

Description

A. M. TAYLOR.

CIRCUIT BREAKER.

APPLICATION r1150 MAR. 18, 1911.

Patented Dec. 14., 1915.

8 SHEETS-SHEET I.

A. M. TAYLOR.

CIRCUIT BREAKER.

AHPLICATION FILED MAR. 18, 1911.

V 1164,320. Patented 1190.1 915.

8 SHEETS-S 2.

MW? /y X 11170111151 8 SHEETS-SHEET 3.

Patented Dec. 14, 1915.

A. M. TAYLOR.

CIRCUIT BREAKER.

APPLICATION FILED MAR.1B. 19x1.

m I g A. M. TAYLOR.

CIRCUIT BREAKER.

APPLICAT'ON FILED MAR. 18. 1911.

1,164,320, Patented Dec. 14, 1915.

8 SHEETS-SHEET 4.

Anal

J V. r Fawn 51% w W 7 ,21 14/ A. M. TAYLOR.

CIRCUIT BREAKER.

APPLICATION FILED MAR. 18, 1911.

1,164,320, Patented Dec. 14, 1915.

8 SHEETS-SHEET 5.

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Wadi.

A. M. TAYLOR.

CIRCUIT BREAKER.

APPLICATION FILED MAR.18.19H.

8 SHEETS-SHEET 6.

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Patented Dec. 14, 1915.

FIG. 9,

f .1 k V 3 .5 1 J A. M. TAYLOR.

CIRCUIT BREAKER.

APPLICATION r1120 MAR.18, 1911.

1,164,320. Patented D10. 14, 1915.

a SHEETS-SHEET 7,.

I ll/J A. M. TAYLOR.

cmcun BREAKER.

APPLICATION FILED MAR. 13' I9! I.

, 1,164,320, Patented Dec. 14, 1915.

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In van/0 I wl'fhesses,

ALFRED MILLS TAYLOR, 0F BIRMINGHAM, ENGLAND.

CIRGUIT-BREE.KEE.

Specification of Letters Patent.

Patented Dec, 14, 1915,

Application filed March 18, 1911. Serial No. 615,308.

To all uiiom 2'23 may concern:

Be it known that I. rlnrnno M. TAYLOR, a subject of the King of Great Britain, residing at Avondale, Ashficld Road, Kings Heath, Birmingham, England, have invented a nev and useful improvement in Circuit-Breakers, oi" Whichthe following is a specification. i

The primary obiject of this invention may be said to be the introduction in a circuit which is under the conditions of short circuit of a resistance or a reactance interjected by the motion of a switch which is caused to operate in a period of time Which is only a 315 fraction of the time taken by the quickest known switches to operate.

A secondary object is the closing of a switch in a period of time much quicker than present obtainable with known switches.

The invention is appl cable in most of its forms ther to direct current circuits or alternat g current circuits Wl h but small modiilcz on.

The principle upon which the switch opcrates is as follows: I is known when a condu r carrying an electric current is 1 cnt b en; upon its there is mutual repulsio etween the two elements of the cur- W ou one of these elements he orin Oi a conductor rigidly A i s'ai "bl nsulators, and the other element to form of a hlads switch i e sac-called knife type, the curca scd to travel dew i "opera 1 from the a the blade the above mentioned is contact am. "1 1 e conouctoi A f .La 1 1 w is and attracted oy til current passing down the other side of each of the coils in such a Way that it can move between the'two coils Without approaching them, the force is then greatly increased, and by making the blade suiliciently light in its moving parts, a force producing an exceedingly rapid acceleration can be obtained. In certain cases when dealing with extra high tension currents it may be advisable in stead of directly opening the high tension circuit, to throw into that circuit a choking coil, and in other cases it may be advis able instead of switching the choking coil into the circuit, to have the choking coil Wound with a secondary coil which is normally closed'by an automatic switch such as above described, and hein thus closed, the secondary currents by their deinagneti'zing action upon the choking coil, can be made to cause the latter to act as a non-inductive conductor until the operation of the said switch, when the reactance of the choking coil is immediately thrown into the circuit.

The rapidity with which the electric current establishes itself on the occasion of short circuit being" so very great, the time its opera; y minute, in fact, to this sort has to be which the switch has to perform tion is correspond l c 'l a D successrui, a switch or capable of commencing; to break the circuit I n in an interval or J3 M l 01 ll $96 110,.

reates; moms blade of the s possib e. s [111% reqi site Hy and c r capacr Several l thods are Lication whereby tns blade c n he reduced below t of the of the cult, short circuit the c lreiit passin blade be intens'" he inve;

(Ft w v a series ct terms of the invention tor breaking the current in the secondary circuit. Figs. 16 and 17 are diagrammatic views showing variations of the forms oi'" the invention shown in Fig. 1. Fig. 18 is a detail view showing a term of the invention applicable to a direct current circuit; Fig. 19 is a detail view of a variation oi the circuit closing mechanism. Fig, 20 is a similar view showing a variation of the invention shown by Fig. 19. Figs. 21' and 22 are diagrammatic detail views showing forms of the invention designed for increasing the number ot' contacts and resistances.

The switch may equally well be mounted in a horizontal position and to operate in a horizontal plane, and for many purposes this is preferable. I

lteterring to Fig. 1, it will be noticed that the main current from the generator or other source to be protected, is led into the hinge of the switch after passing through the lined coil a, after passing through which is flows through the blade oi the switch Z) in an upward direction as indicated by the arrow 70 until it comes into connection with the principal contact jaw m from which it is led away by the conductor it back to the main circuit. it will be noticed that in addition to the contact jaw we there are a number of smaller cont act jaws e e tc, arranged radially to clip on to the blade and between each of these smaller contact jaws there is a non-inductive resistance 7 7' 810., which may consist of a thin strip suited for dissipating the heat very rapidly. will further be. noticed that there are two or more principal contact jaws n and 0 arranged circumferentially with reference to the motion of the switch, and that between these jaws there are other much heavier non-inductive resist ances such as d d Neglecting for the moment the other portions of the switch, and considering the action of those portions which have been up to the present mentioned, we will now consider the actions that obtain when the switch is blown out of its position by the intense magnetic field in which it is placed. This magneticlield, due to the coil a is at right angles to the paper, and passes across the blade Z) of the switch. The field can be intensified very greatly by the employment of suitable laminated iron stampings arranged to complete the magnetic circuit around the back of the panel or framework which carries the switch. The etlect 'oit'tl is will be th when blade Z) the switch is blown outward as shown by the large arrow, due to the repulsive action, the arcs formed at small contacts 6 6 etc, are in the intense magnetic field in which the blade itseli moves, with the result that there is what is known as a very tense m gnetic blow out action l M th current passing across these arcs. llhese contacts moreover, together with the whole switch, can be immersed in an oil bath with the additional efiect of quenching the arcs at these contacts. Another important effect obtained Before the blade 0 has parted company with the bottom contact oi the radial line of contacts, the top of the said blade has made contact with the second of the circumferential contacts a. lhere is therefore no total interruption of the current at any point from the time of the blade leaving the contact at until it reaches the contact n. The

lads in tact would be designed of a sufiicient width to come into contactwith the contact jaws a before it left the contact jaws m. The value of this combined arrangement of radial and circumferential resistance is that the current is induced to flow through the non-inductive resistance at, not

suddenly, but by a succession of steps each of which increases the difference of potential applied to the non-inductive resistance d, by an equalamount. There therefore tends to be no sparking whatever when the blade leaves the contact jaw no, because the whole current is not forced suddenly into the resistance G3,. Should it be desired to add additional radial contacts a second line of these can be added radially between the principal contact a and the hinge of the switch. 5

it will be noticed that the blade ot the switch is provided with a cranked end 3 to which is attached a spring 70, the angle of the crank being so chosen that when the switch'is in the closed position the spring tends to hold it in thisposition against the magnetic repulsive action of the current ordinarily circulating in the switch. When, however, the blade of the switch opens be- Elli yond certain angle, the point or" the application ot the force ot the spring passes over the dead center and tends to keep the switch opened. lit, however, is not desired that should happen, the spring can be arranged so that tends to close the switch from all open positions.

j will be noticed thatthere are sundry insulating barriers c 0,, do, shown in Fig.

These made of a refractory and ina j J:

sach as mica, and are ior one i'roin travcling upward along the line of contacts 6, 22

etc, instead of the spark at each contact bethe blade 5 moves out from the switch, the

oil could not, by virtue of its inertia, occupy the space left by the blade sufficiently rapidly, and a partial vacuum would be formed behind the blade, whichwould leaveopportunity for an arc to commence. By the arrangement indicated the arc is entirely crushed out, and is given no opportunity to get a start.

Coming now to the method by which the current through the blade when a short circuit occurs is enormously increased above that even in the short circuit, it will be noticed that the main line current is caused before entering the fixed coil (1 of the switch, to circulate around the primary coil .9 of a transformer conventionally illustrated. (which may or may not have iron. in its magnetic circuit), and the secondary r of this transformer is so wound that the current induced in it is the desired multiple of the current passing through the primary coil 8. This secondary current is led into the bottom. and top of the switch blade by means of the hinge at the bottom and the contact jaw 17 at'the top, and the connections are so led that the current is made to traverse the blade in the same direction as the main line current, and so to multiply the effect on the blade in proportion to the combined current. By dispensing entirely with iron in the small transformer r s, the current from the secondary coil 1* may be made as nearly absolutely synchronous with the main line current as we please. The transformer 1" s will not require to be at all large, since the only energy it has to generate is that due to the energy being lost in the blade 7; of the switch, and since the resistance of this is low and the reactance cannot be very high, the cost of this small transformer will not be appreciable.

Vith a view to still further reducing the weight of the blade 6, owing to its having to carry the main line current continually, I may arrange a second primary coil t supplied from a source of E. M. F. through a resistance j, and arranged under normal. working to somewhat over-compensate for the ampere turns due to the primary coil 8 in such a manner as to produce a small flux through the core of the transformer which shall be in the opposite direction to the flux which is to be produced by the main primary coil under conditions of short circuit.

The E. M. F. in the secondary coil r will therefore be in the reverse direction to that in which it is intended it shall operate under conditions of short circuit, and this E. M. F. will produce under normal conditions a current downward through the blade (see Fig. 1), opposing the flow of the main line current, and incidentally assisting the fiow of the main line current through the second ary coil r instead of through the blade, thus relieving the blade of the necessity of carrying any appreciable current under normal working conditions, and thus permitting its mass to be reduced. In order to prevent the I auxiliary primary winding 2,, which is energized by the E. M. F. of the generator, from operating as a closed secondary coil (discharging into the generator) at the time of short circuit, the resistance or reactance j is arranged to abstract a considerable proportion of the E. M. F. of the generator, only a small proportion being thus left to be applied to the 0011 t. When the short circuit occurs, and 2, becomes the generating coil it is unable to produce a large demagnetizing current on account of the large resistance or reactance j.

In Fig. 3 a detail perspective view of a simple form of the invention has been shown as an actual structural device to enable the construction and operation to be readily determined by inspection. The principle of operation is the same as described above in connection with Figs. 1, 2, and 3. The current from the generator G after passing through the fixed coil a, enters the switch blade I) at the hinge and passes through the blade Z), contact m and conductor 15 to the line. The return circuit is through the conductor 16 to the generator.

\Vhen the switch blade is thrown to open position by the magnetic field between the poles of the electro-magnet core a on which the coil or is wound, the blade first leaves the contact jaw m, and then the smaller contact jaws e 6 etc., in succession, so that the noninductive resistances f f etc., connecting the contact jaws are successively introduced into the circuit in series. For the sake of simplicity of illustration only a single radial series of resistances is shown in this view. Additional resistances and contacts may be used as disclosed in connection with Figs. 1, 2 and 3. The operation of the transformer r s, the auxiliary coil t, and the reactance j, in reducing the normal current through the switch blade and enormously increasing the current through the switch blade under the conditions of a short circuit, have been fully set forth in connection with Figs. 1, 2 and 3.

Referring to Fig. 4i, an instantaneous switch of the type shown in Figs. 1, 2, and 3, but'mounted in a horizontal position, is shown, and arrangements are shown wheretill by such a switch could be closed from a switch board at a distance, and could be yet entirely free to open automaticallywithout increasing to any appreciable degree the inertia of the parts which have to be moved rapidly. A similar arrangement could be got out in which the blade of the switch moves in a horizontal plane instead of a vertical plane as in ig.

Referring now in detail to Fig. 4, it will be seen that the blade at carries at its entremity a piece 6 hinged as shown, and con trolled by a spring in such a way as to make it take up a position in line with the "rest of the blade unless extreme forces are brought to bear upon it. A. link d engages as shown with the underside of the piece 6 of the blade and this-link is carried by a rod passing through the roof of the box which carries at its extremity a catch 6. Inside the bOX is a spring f which is compressed when the switch is being closed.

For the purpose of engaging with the catch 6 from the operating board, a bell crank g pivoted at g is provided to the left hand end of which a trigger it provided with a spring j is pivotally attached. The trigger 71, carries a tail piece is, and when the crank g is rotated in the direction indicated, by the operating rods connecting with the main switch board, this tail piece It comes into contact with the fixed stop 'Z which causes the trigger piece which had been previously engaged with the catch 6 to lose contact with the catch e, and the link at (to which the catch is attached as already explained) immediately falls to its bottom position under the action of the spring 7". The blade at, however, does not follow the link d, the slot in the link permitting the link to move independently of the blade, and the blade remains in the closed position, held there partly by the triotion of the contact jaws m and partly by the spring a. 'W hen, now, it is desired to again close the switch from the switch board the crank g is rotated backward until the trigger piece 72, engages with the catch-e, and.

the switch is then ready for closing. lt will be understoodthat the switch shown in Fig. is adapted to have combined therewith automatic means for opening switch as shown in l and other figures.

@ther methods of decreasing the weight of blade, alternative to the method proposed in Fig. l are shown in l igsh, 6, 7, 8, 9.

lln Fig. is shown an arrangement in which the fixed coil a. which deflects the blade 5 is shown in a parallel circuitto the blade with a view to normally carrying the bulk of the current. In order to keep the current out of the blade in normal working a stationary reactance coil lit, which may be mounted on the same magnetic core as the it from the blade.

iaeasao main deflecting coil, is put in series with the which is, further, insutficiently laminated,

the'result being that with the ordinary rate of change of induction, this core answers sulliciently to keep the current out of the blade; but that'with the extreme rate of change of induction obtaining on short circuit, the coilis unable to keep the rush of current from the blade. Both in this case and in Fig. 5 the blade of the switch can be utilized to disconnect the main fixed coil or from the circuit before the switch blade interrupts the main circuit, and in order to reduce sparking from this cause, a non-inductive resistance may also be placed in parallel circuit with the fixed coil.

, In Fig. 7 is shown another arrangement for reduping the current normallyv flowing through the blade of the switch. A reactive coil R is shown here as-in Fig; 6 in series with the blade, but instead of depending upon the current passing through the blade to give the reactive efiect, a second coil R connected with a source of E. M. E. is caused to induce in the reactive coil aback E. M. E

through the fixed coil a, and thus to abstract TV hen a short circuit occurs, there is no E. M. l between the mains, and the two E. M. E. coils behave as partly closed secondaries, facilitating the flow of current through both branches of the circuit. I

ln Fig. 8 is shown an arrangement for a similar purpose where no E. M. E. coil is available. Two reactive coils T and U in this case are inserted in series with the fixed coil a, as shown, and the main line current is taken around a second winding U wound over one of these, inducing an E. M. E. in such direction as to force current through the fixed coil as. The other reactance coil T is wound on a core which is insufiiciently tired coil itself is shunted, as. shown in Fig.

9, by a reactance coil V over which is wound a coil V supplied from a source of E. M. F. tending to induce in the reactive coil V an E. M. F. which sucks the current through this coil in preference to going around the fixed coil In Figs. 10 to 15 is shown a series of arrangements for breaking the current in the secondary circuit rather than in the primary circuit. The simplest of these is shown in Fig. 10 and requires no explanation. The switch of the type shown in Figs. 1, 2 and 3 is simply connected in the secondary circuit of a large transformer whose primary circuit is in the main line high tension circuit.

In Fig. 11 is shown an arrangement whereby a single switch in the high tension circuit can introduce reactance into the three phases of the said circuit. Conductors 1, 2 and 3 from these three phases are led around the core 4 of a transformer in such adirection that when the currents in the three phases are equal, no magnetic flux is produced, but when an out-of-balance current flows, due to a fault on any one phase, a very heavy flux is immediately induced in the iron, and a large secondary current is-thereby generated in the coil 5 which in turn acts to operate the instantaneous switch a, I).

In Fig. 12 another arrangement is shown more suitable for operating with a short circuit on all three phases than with an out-ofbalance current. One of the three primary windings 1, 2, 3, as for example the winding 2 is arranged to have fewer ampere turns than the other two, but this is compensated for by a coil 6 sup lied from a source of E. M. F. and norma ly connected up to this source of E. M. F. by means of the instantaneous switch a, b, which is itself supplied from a secondary coil 5 on the said transformer. When now a short circuit occurs, the pressure goes down and the arrangements are thrown out of balance magnetically, with the result that a large current is generated in the secondary coil 5, which operates the instantaneous switch in the predescribed manner.

In Fig. 18 is shown an arrangement for causing the current in the secondary coil to run up at a greater rate than would be the case by direct induction from the primary circuit. In this arrangement a transformer is shown, consisting of three limbs, the windings on the two outer limbs of which are in the primary circuit, and are connected in parallel one with the other. On the central limb is wound a coil 0 capable of abstracting flux from the one outer limb, and adding it to the other outer limb.

- When the rush of current comes, the main line current which traverses this central coil operates to greatly increase the flux on say the right hand limb of the transformer,

with the result that the current generated in the secondary coil shown on this right hand limb is greatly increased, and the switch opens the more rapidly. In order to prevent the central coil from producing this effect in the normal workin another coil cl supplied from a source of M. F. is also wound on the central core, and in such a di rection that when the E. M. F. is normal, the effect of the main line current on the central core is .practically eliminated. When the short circuit occurs, the efiect of the E. M. F. coil is relatively very small, and the action above alluded to can take place.

In Fig. 14 is shown an arrangement for increasing the force on the blade where it is desired to break the high tension circuit in the three phases of the supply to a consumer if an out of balance current occurs in any one phase. The object of the arrangement shown here as against that shown in Fig. 11 is that whereas Fig. 11 requires a very large transformer in order to insure the requisite choking efi'ect in order to keep down the current in the main line, Fig. 14 can be operated with a very small transformer, since in this case, the current induced in the secondary coil is caused to open the switch and break the primary circuit, and thus no reactance is required to be introduced in the transformer itself. In the arrangement shown, the secondary coil has, of course, to be disconnected by means of the switch from the circuit before the primary circuit is opened by the switch. This is easily arranged by means of the contact (0) as shown.

In Fig. 15 We have the same arrangement as Fig. 14 except that a magnetic circuit containing no iron, or containing a large air gap, is substituted for that containing iron without an air gap.

In Figs. 16 and 17 are shown alternative arrangements to Fig. 1 to meet thercase where it is required to permanently insert a large choking coil in the circuit on the occasion of a short circuit, as for instance, where, in a'large generating station, it is desirable to break up the bus bars into two or more sections, and connect these by choking coils. By means of the present invention the choking coil can be normally cut out of the circuit and automatically thrown into circuit without undue rise of potential. When the choking coil is only to be used for the purpose of restricting a short circuit current for a short period, the above arrangement greatly reduces the cost of the copper in the said choking coil.

Referring to Fig. 16 it will be seen that a choking coil 8 having a very large num ber of tappings is connected in place of the non-inductive resistances f f. etc., of Fig. 1, and these sections are thrown in rapid succession by the opening of the switch.

The switch itself is precisely similar in-its arrangement to that shown in l ig. 1.

Fig. 17 shows an alternative 'method which avoids the construction of a choking coil with a number of tappings, which might lead to breakdowns in the insulation, and retains the non-inductive resistances f f etc., shown on Fig. l but substitutes the choking coil 9, which may be in two or three sections in place ofthe circumferential resistances (Z, d, of Fig. 1. By this arrangement the choking coil has successive increme'nts of E. M. applied to it, causing the current to rise in corresponding stages, instead of being called upon to instantly receive the whole of the line current. if found desi able, a second line of radial contacts as shown may be employed, or even a third line, the choking coil being in this case divided up into two or three sections, each of which is put across a pair of the circumferential contacts as shown for 2 sections.

lln Fig. 18 is shown an arrangement more particularly applicable to a direct current circuit enabling the mass of the blade to be reduced by the device of splitting the main current (where large) among several blades in parallel circuit, the cooling surface for a given amount of rigidity in the blade being thus increased, and more current being thus permissible to be passed through the blade. The blades move in very intense fields which are really all one field, the air gaps between blade and blade being bridged magnetically by the blocks marked N. S. A single pair of exciting coils was shown, may thus be utilized to provide the held for a number, of blades magnetically inseries anda magnetic blow out is also provided for the arc of ample strength. The magnetic circuit is of course, completed by a solid loop of iron around the back of the switchboard. ln certain cases it may be desirable to couple the blades in series with one another, but where they are coupled in parallel circuit, they may with advantage be carried on a single hollow shaft, to which they are keyed as indicated, so that they all operate with the same velocity. Non-arcing barriers are interposed near the breaking contacts between bladeand blade.

lln Fig. 19 is shown an arrangement for instantaneously closing a circuit by the action of current from a source of direct cur- K rent supply energizing a coil so as to produce a very strong held, in which the blade is placed as indicated. 'lhis blade makes contact at its movable extremity with the contact jaws u and by means of thesecontact jaws or brush and the hinged contact at the other end of the blade a current of very large amount may be momentarily sent through the blade from a source of ens y such as say, two or three cells of a storage battery v as shown, the circuit being closed by i ea-sac means of a switch to. The interaction be- E. M. l provides a force of great amount (which can be increased by the use of iron in the circuit) propelling the blade with great velocity toward the high tension circuit to be closed. It can be arranged if de sired that the blade of the switch is prolonged at the hinged end, and that this prolongation only makes contact with the jaw during the first part of the motion of the blade, so that the low tension circuit is disconnected entirely from the high tension circuit before the latter is closed.

lln Fig. 20 a somewhat similar arrangement is shown, but in this case the switch is closed by means of an alternating current. A small alternating current transformer rs has its primary circuit energized by an alternating current which passes through the fixed coil a and is connected direct on to the mains. lln the secondary coil r of the above transformer a very large current of very low voltage is generated which is sent directly through the blade I) of the switch in the.

same way as was the battery current in Fig. 19. @n closing the switch 10 the blade 6 of the automatic switch is propelled with great force toward the main line contacts.

Referring generally to the whole of the arrangements shown throughout this specilt cation for the operation of the instantaneous switch, it may be stated that though referring principally to the useof alternat' ing current, the arrangements will all hold with direct current provided that'the flux due to the normal current traversing the coils of the transforn'iers, etc., does not produce anything approaching saturation in the iron. 'lo efi'ect this result the iron circuit should be incomplete, and in some cases it will be desirable to avoid an iron circuit altogether. Fig. 15 for instance, is an arrangement that would be employed as well with direct as with alternating current.

It will be understood that, where the main line currents (more especially in the case of direct currents) are so large that diiiiculties would be encountered in making the switch blades and contacts suthciently heavy to carry such currents, the method of employing a closed secondary coil shown in Figs. 10 to 15 can be employed with the difference that the number of turns in the secondary coil can be increased above that in the primary, and the operating currents in the secondary consequently reduced. though the ll M. F. to be broken will. of course, be correspondingly increased. The arrangements of the automatic switch working in oil permit, however, of these higher voltages more readily dealt with than the higher currents, so far as the tarsal-ring the concerned.

its

ing split up equally among them.

menses As has already been noted, if an increased number of radial contacts above that shown in Fig. 1 were required, they could be obtained by providing one or more radial lines of contacts, the switch blade as it moved outward coming successively into contact with these radial lines of contacts and their resistances.

Figs. 21 and 22v illustrate a modified construction for effecting the same result; that is, increasing the number of contacts and resistances. In this arrangement, I utilize two or three blades, which, with their lines of radial contacts, are separated only by the space necessary to accommodate the fixed coils which produce the. magnetic field, which is arranged to traverse the whole of the blades acriatz'm. in the more general case, namely, that in which the main line current is comparatively small and the voltage high, I connect the two, or three, blades electrically in series and I so arrange that the three, or two, blades shall be driven out of their seats all at precisely the same speed, that is, that they shall maintain their relative angular positions as they move outward. The way in which this is performed will be best understood from the details of the arrangement given on the drawing.

Fig. 2l-shows the three blades 5 b 6 mounted side by side which, with their lines of contacts, 6, e, e, are operated by the fixed coils a a (1 three blades being assumed to be employed.

Contacts g 9 51 ,9, are arranged in connection with the secondary coil or coils r r 1, of the auxiliary transformer or transformers, 7' 8 7' 8 1' .3 (see Fig. 22), the blades 6 b 5 as they move outward, passing through these contacts.

Referring to Fig. 22 which is a diagram -matic view of the electrical connections, it

will be seen that, between these contacts g g 9*, there are arranged resistances, of very low value, and large currentcarrying capacity, suitable for receiving the heavy currents supplied by the secondary coil or coils r r 7- of the auxiliary transformers.

It will also be noticed that the primary coils s s a of the three auxiliary transformers, are arranged in parallel circuit with one another, the main line current be- It will further be noticed that in each branch there is a pair of haltcoils, (4 included in series with the primary coil of the auxiliary transformer.

t should be mentioned that the contacts g g g are made very narrow in a circumferential direction, so that a very small movement of the blades if, 6 5 can rapidly insert resistances in the secondary circuits of the auxiliary transformer.

The is as ache-ave:

'rush of current comes, it divides itself consequence driven out with great force. Should, however, one blade move more rapidly than the others, owing to less friction in its contacts, or other cause, there will be a greater resistance in the secondary circuit supplying that blade, with a consequent diminution of force, thereby tending to slow down the speed of the blade. Also, owing to the secondary current being less, the primary current, and consequently the current in the fixed coil, will also be less, the demagnetizing eflect of the secondary being reduced. Consequently the speed of motion of the blade will be doubly retarded. By this means any blade tending to move unduly rapidly is kept back in such a manner that the other two blades can obtain the same angular position.

, aving now particularly described and ascertained the nature of the said invention, and in what manner the same is to be performed, I declare that what I claim is:

1. In a switch adapted for instantaneous automatic operation under excessive momentary currents, the combination of relatively movable elements of the circuit positioned to have a reacting force applied thereto by the current therein, said elements movable relatively to each other by'the reactive force of the current therein, and means operable when the current in the circuit is increased to cause the reactive force between said elements to increase in a greater ratio than the product of the increased current in said elements.

2. In a switch adapted for instantaneous automatic operation under excessive momentary currents, the combination of a portion of the circuit arranged to produce a mag netic field when a current flows in the circuit, a switch blade in said magnetic field and forming part of the circuit, and means brought into operation by an increase of current in said circuit to cause the strength of the magnetic field to increase much more rapidly than the said current increase, and thereby produce an intensely powerful magnetic field when a heavy current flows in the circuit.

3. in a switch intended for automatic operation under excessive momentary currents, the con'ibination of a circuit comprising a deflecting coil, stationary contact, and a switch blade in engagement with said contact and movable away from said co the rearive 1? rec of electrically connected without material resistance therebetween and thereby having substantially the same potential, the blade and coil being in close proximity without tendency to spark across from one to the other, and means brought into operation by an increase of current in the circuit to multiply the intensity of the increased current in the coil and blade, and thereby multiply the reactive force between the coil and blade tending to move the blade away from its contact.

l. lln a switch intended for automatic instantaneous operation under excessive momentary currents, the combination of a movable switch blade, a deflecting coil'in circuit with the switch blade, and atransformer having a primary winding in circuit with the switch blade, and a secondary winding arranged to discharge into the switch blade, the transformer having also an auxiliary Winding, which auxiliary winding is arranged to reduce the reactive effect between the switch blade and the deflecting coil during the normal flow of current.

5. In a switch adapted for instantaneous automatic operation under excessive momentary currents, the combination of a switch blade, a reactive coil arranged to react on the blade and move it to open position when subjected to an excessive current, inductive means energized by the said current in part of the circuit separate from said coil to multiply the current in the switch blade, and a till spring arranged to hold the switch in both open and closed position;

6. ln a switch adapted for instantaneous automatic operation under excessive momentary currents, a switch blade, means to cause an excessive current in the circuit toreact on the blade and open the latter, inductive means energized by the said momentary currents to multiply the current in the switchblade and thereby multiply the reactive power tending to open the blade and means to automatically return the blade to closed position if the short-circuit clears itself be fore the blade reaches a predetermined point in the openingmovement.

7. lln a switch adapted eration under excessive momentary currents, the combination of a switch blade and a stationary switch contact to cooperate with the rapidly than in the remainder of the circuit.

8. ln a switch adapted for automatic operation under excessive momentary currents, the combination of a switch blade and a stationary switch contact to ooperate with the blade, means in circuit with said blade to re act on the said blade, and an intensifier associated with said blade and causing the curfor automatic oprent in the blade to increase more rapidly than the main current in the circuit.

9. The combination of a switch blade, a coil in circuit therewith and positioned to react thereon when a current flows, a shunt circuit across said switch blade, and a transformer comprising a primary coil in the main circuit and a secondary coil in said shunt circuit, the short circuit being so connected across the switch blade that upon an overload the current through said shunt circuitwill react on the current, in the blade so as to tend to move the blade to open position.

10. In circuit breaking apparatus, the combination of a movable switch member, a

coil in circuit therewith and positioned to V react thereon when a current flows, a transformer comprising a primary coil in the main circuit and a secondary coil connected ina shunt circuit across said switch member, and a second primary coilreceiving current from a separate source and reacting on said secondary coil, said secondary coil being so connected thatupon an overload, the current therein will be in a direction such that the reaction between said secondary coil and switch member will tend to move the latter to open position.

11. ln a switch intended for instantaneous automatic operation under excessive momentary currents, the combination of a movable switch blade, a deflecting coil, and a transformer having a primary-winding connected in circuit with the switch blade, and a secondary winding connected to dis charge into the said switch blade, said secondary winding arranged to magnify the reactive effect between the said switch blade and the deflecting coil, and thus, for a given short circuit current, to diminish the time taken to open the switch; also the combination therewith of an auxiliary primary winding of the transformer arranged to cause theesecondary winding of the said nected in clrcuit with the switch blade, and

a secondary winding connected to discharge into the said switch blade, said secondary winding arranged to magnify the reactive effect between the said switch blade and the deflecting coil, and thus, for a given short to open the switch.

l3. The combination of a main circuit of an alternator or bus bars, a movable switch blade therein, a deflecting coil also connect ed in the said main circuit, and a transtransformer to abstract current from the M0 circuit current, to diminish the time taken former whose primary coil is also in the said main circuit, said transformer having a secondary winding arranged to discharge into the switch blade in such a way as to increase the deflecting force on the switch blade due to the above mentioned deflecting coil, the transformer having also an auxiliary E. M. F. winding connected across one phase of the alternator or of the bus bars, which auxiliary winding is arranged to reduce the reactive elfect between the switch blade and the deflecting coil during the normal flow of current.

In a switch intended for instantaneous automatic operation under excessive monientary currents, the combination with a source of E. M. F., of a switch comprising a movable blade, a deflecting coil, and a transformer having a secondary coil wound for very heavy currents, said secondary coil arranged to discharge across the blade of the switch in such a manner as to assist the fixed coil to deflect the switch blade, said transformer comprising a primary coil traversed by the main line current during the time of the short circuit, an auxiliary primary (E. M. F.) coil, and a choking coil in series therewith, said auxiliary coil supplied from the source of E. M. F. in such a way that its ampere turns overbalance the ampere turns of the main primary coil under normal working conditions, with the object of keeping the main line current out of said blade during normal working conditions and permitting a reduction of the mass of the blade and an increase in its acceleration on a short circuit occurring.

15. The combination with a main generator circuit and a switch blade therein, of a coil in circuit with said blade and positioned to react thereon when a current flows, a transformer comprising a primary coil connected in series with the said circuit and a secondary coil connected as a shunt across the blade, and so arranged that upon any abnormal increase in the primary or main line current a greatly intensified current is induced in this circuit in such a. direction as to assist or increase the current in the switch blade tending to deflect the blade.

16. In circuit breaking apparatus, the combination of a main circuit, a movable switch member therein, a coil in circuit with said switch member and positioned to react thereon when a current flows, a transformer comprising a primary coil in the main circuit and a secondary coil connected as a shunt circuit across the said switch member and so arranged that upon any abnormal increase in the primary or main line current a greatly intensified current is induced in the shunt circuit in such a direction as to assist or increase the current in the switch blade tending to deflect said blade, said transformer having a second or auxiliary primary coil wound with many turns, a reactance, said reactance in series with said auxiliary primary coil in a potential circuit from the terminals of the generator and so connected that the magnetism due to the current in said auxiliary coil will, under normal conditions, oppose and overbalance the mag- ALFRED MILLS TAYLOR.

WVitnesses ERNEST HARKER,

ETHEL M. Vans.

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