No. 701,958, Patented June 10, 1902. C. P. STEINMETZ. AUTOMATC CUT OUT. (Application filed Mar. 6, 1899.) (No Model.)

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Witnesses, Inventor. -4 N.-46 (0. Cls O Steinmetz 4,5404 by 4.40als.J4tty.

UNITED STATES PATENT OFFICE.

CHARLES P. STEINMETZ, OF SCHENECTADY, NEW YORK, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK. AUTOMATIC CUT OUT.

SPECIFICATION forming part of Letters Patent No. 701,958, dated June 10, 1902. Application filed March 6, 1899, Serial No. 707,880, (No model.) To all tuh-On, it may concert: inverted by normally Supplying the same Beitknown that I, CHARLES P. STEINMETZ, with and deriving alternating a citizen of the United States, residing at currents therefrom, the speed of the machine Schenectady, county of Schenectady, State of is varied not only by changes in electromotive New York, have invented certain new and force of the direct current supplied, but also 55 usefulmprovements in Automatic Cut-Outs, by changes in the character of the load on the (Case No. 1,037,) of which the following is a alternating - current end of the machine. specification. - Thus if an inductive load is fed from the al In the practical operation of rotary con ternating mains the lagging currents pro IO verters I have found it desirable to provide duced thereby react upon the field-magnets Some automatically-actuated means for cut of the rotary converter and cause a weaken ting the machine out of circuit or otherwise ing of the same, the immediate result of which reducing its speed upon a predetermined rise is a speeding up of the rotary converter, in speed-as, for example, twenty per cent. such as would take place in a direct-current above the normal. The causes which give motor if the field were weakened. On the rise to changes in speed in a rotary convertel other hand, if leading currents flow in the ... are dependent upon the circumstances under alternating mains the effect of the same is to which the machine is operated. If the ma strengthen the field of the rotary converter chine is used in the ordinary manner, with and to correspondingly decrease its speed. supplied thereto and di This has been a serious and in some cases a rect currents taken from the direct-current prohibitive difficulty in the employment of end, the machine will run in synchronism inverted rotary converters. With the frequency of the alternating current In order to provide a speed-limiting mech Supplied, and its speed will change only with anism suitable for employment in the cases changes in frequency of the alternating cur above mentioned, and, in fact, in connection 75 rent. It sometimes happens, however, that with any -electric machine generat the generators supplying the alternating cur ing alternating currents or to which alternat rent speed up abnormally, thus requiring ing currents are supplied, I make use of a some safety device in connection with the ro circuit connected across the alternating mains 3O tary converters or other machines driven and responsive to the frequency of the elec therefrom in order to prevent too great rise tromotive forces impressed thereon; and this in speed and consequent destruction of the circuit is arranged to automatically actuate or machines by the action of centrifugal force. control suitable devices for cutting the ma It also sometimes happens that the alternat chine or machines. out of circuit or for other 35 ing supply-mains of a rotary converter are wise reducing their speed when the frequency interrupted. If the direct-current end of the of the alternating electromotive forces reaches rotary converter is connected to an independ a predetermined abnormal value. ent circuit, no harm will result. If, however, My invention will be more readily under the direct-current end of the rotary converter stood by reference to the following descrip 40 be connected with the direct-current end of tion, taken in connection with the accompa the rotary converters or, indeed, with any other nying drawing, while its scope will be clearly 90 source of direct current, the immediate result and particularly pointed out in the appended is a reversal of current in the direct-current claims. side of the rotary converter, which thereupon For purposes of illustration I have shown runs as a direct-current motor. If the ma my invention as applied to a rotary converter; 95 chine is provided with a series field-Winding, but it will be readily understood that the same as usual, the fieldstrength is reduced by rever may be utilized in connection with any other sal of current through this winding, and the alternating-current dynamo-electric machine, machine therefore speeds up. If, on the other At R, I have indicated diagrammatically a 50 hand, the function of the rotary converter is rotary converter; but for the sake of conveni, IOC) 2 701,958 ience I have omitted showing the field-wind- mature O of the magnet M to be attracted, ings, which, however, may consist of the usual thereby causing the contact P to close the shunt and series coils. The particular con local circuit fed by the battery Q or other struction of the rotary converter is unim source of electromotive force. Current then portant so far as my invention is concerned. passes through the circuit-breaker coils l l in The direct-current, mains are indicated at and operates the circuit-breaking contacts a, b, and in series with the mainly have shown used in connection there with, thus opening a suitable circuit-breaker or other cut-out de the alternating-current and the direct-cur vice, the same consisting of a bridging-piece rent mains of the machine. 75 O c, making contact with the terminals cle and While I have shown a local circuit for Op held in place against the same by a toggle erating the circuit-breakers in the mains of connection f. The knuckle of the toggle is a dynamo-electric machine, it will of course held in place by the tripping-lever 9, the lat be obvious that any other Suitable means ter being actuated by current in the coil li in controlled from the tuned circuit may be em a manner to be hereirafter described. ployed for carrying out the same functions. The alternating - current mains are indi IIaving thus described my invention, What cated at i, j, k, and in series with two of the I claim as new, and desire to Secure by Letter's mains ilk are placed circuit-breaking devices, IPatent of the United States, is each similar in all respects to that placed in 1. The combination of alternating-current the direct-current main b. It is unnecessary and direct-current mains, a dynamo-electric to describe the circuit-breakers in detail, since machine connected to both sets of mains and they may be of any suitable and well-known driven by energy transmitted over one of construction. It will suffice simply to state said sets of mains, a circuit supplied With Cllr that the circuit-breakers are actuated by rent from said alternating - current mains, means of current flowing in the respective means for causing the current in said circuit coils l and 7. to increase with increase of frequency of Cur The means which I have provided for en rent in said alternating-current mains, and ergizing the coils hl in for tripping their re means controlled by current in said circuit spective circuit-breakers consists, primarily, for interrupting the supply of energy to Said 95 3O of a tuned circuit placed across one pair of dynamo-electric machine. the three-phase mains if l-as, for instance, 2. The combination of a dynamo-electric across the mains ilk. This circuit includes a machine, alternating-current and direct-cul'- condenser C and a device giving rise to in rent mains extending therefrom, a circuit-in ductive reactance, which is here shown as a terrupting device for one of said sets of do 35 magnet M. I may, if desired, provide an ad mains, a circuit connected across the alter ditional inductive device of any suitable form, nating-current mains, means for causing Cul'- as indicated in dotted lines at N. The core rent in said circuit to increase with increase of the magnet M is vertically arranged with of frequency of the alternating electromotive two downwardly-projecting legs, to one of forces impressed upon said alternating-cur IO5 40 which is pivoted one end of an O, rent mains, and means actuated by current the other end of which normally rests against in said circuit for operating said circuit-in a suitable stop S and is by the latter main terrupting device. tained at a suitable distance from the other 3. The combination of alternating-current leg of the magnet-core. The free end of the mains, means for impressing thereon alter IO armature O carries a Wedge-shaped contact nating electlomotive forces of normal fre 45 P, adapted to be brought into engagement quency, a circuit connected to said mains, with and to connect the two terminals q, and means for causing the current in said circuit O, thus serving to complete the circuit of a to increase with increase of frequency of cur local battery Q or any other suitable source rent in Said mains above the normal, and II5 So of electromotive force through the circuit means operative upon increase of current in breaker coils h, l im, which, as here shown, said circuit for interrupting the flow of cur are arranged in multiple with each other, but rent in said mains. Which might equally as Well, if desired, be 4. The combination of a dynamo-electric arranged in series. The capacity reactance machine, conductors in connection there with 55 and the inductive reactance in the tuned cir on which alternating electromotive forces are cuit are so proportioned with respect to each impressed of a frequency corresponding to other as to bring the circuit into resonance the speed of the machine, a tuned circuit in at that frequency of the electromotive force connection with said conductors, a local cir in the alternating-current mains at which it cuit controlled by current in the tuned cir I 25 is desired to cut out or otherwise act upon the cuit, and means controlled by said local cir rotary converter or other dynamo-electric ma cuit for interrupting the driving power of chine to reduce its speed. When this condi said machine. tion of resonance is reached, the current in 5. The combination of a rotary converter the tuned circuit increases very greatly, and of variable speed, alternating-current and di the parts are so proportioned that this in rect-current mains, circuit-interrupting de Crease of current is sufficient to cause the ar vices for said mains, a tuned circuit connect

701,958 3. ed across two of the alternating mains, and ling both the alternating-current and the di means operated by current in said circuit for i rect-current mains. controlling the circuit-interrupting devices. In witness whereof I have here unto set my 6. The combination of a rotary converter hand this 4th day of March, 1899. alternating-current and direct-current mains, CHARLES P. STEINMETZ. a tuned circuit supplied with energy from Witnesses: the alternating mains, and means responsive BENJAMIN B. HULL, to current in said tuned circuit for interrupt- MABEL E. JACOBSON.