US821936A - Current-regulator. - Google Patents

Description

YNO. 821,936.

PATENTED MAY 29, 1906.

W. K. GIBBONEY.

CURRENT REGULATOR. APPLICATION FILED NOV. 19, 1904.

UNITED STATES P TENT OFFICE.

WILLIAM K. GIBBONEY, OF BUFFALO, NEW YORK, ASSIGNOR TO THE PITTSBURGH REDUCTION COMPANY, OF NEW KENSINGTON,'PENN- SYLVANIA, A CORPORATION OF PENNSYLVANIA.

Specification of Letters Patent.

CURRENT-REGULATOR.

Patented m yee, 1906.

Application filed November 19, 1904. Serial No. 233,391-

my invention.

My invention has been especially designed for the regulation of a group of electrodes in an electric furnace by which they can be reg- .ulated independently and automatically, so as to maintainconstant and uniform conditions, and by which, if desired, the current applied to all the several electrodes may be varied and adjusted simultaneously. Where a number of electrodes are used in a single electric furnace regulation of this kind is of the current supplied to the electrode may be varied as desired.

In the accompanying drawing I show two electrodes 2 2, which are regulated by the apparatus which I am about to describe; but

the invention can be ap lied to the regulation of any number of e ectrodes, all that is essential being to provide each of them or each unitary group of them with individual regulating devices constructed in accordance with my mvention.

- The electrodes 2 '2 are supplied with current from a circuit 3 and a generator 4, which may be an alternating-current generator, as shown on the drawing, or it may be a generator of direct current. Each electrode 1s provided with a mechanical feeding device by means of which it is either raised or lowered in accordance with the current conditions necessary to be maintained.

I do 'not show the feeding mechanism in the drawing; but it maybe. of. any suitable type, and it is controlled by my improved regulating .device. This device in theform in which I show it comprises an oscillatory armature 4, mounted between poleieces 5, the field being constituted by 00' s 6 6, wound u on the ole-pieces. The strength of the fie d is reglfiated by a rheostat 7, and preferably also by a rheostat 8, which is in the circuit with the armature-coil, the field and armature coils being in the circuit which is independent of the circuit tobe controlled :and is preferably constant, or nearly so, so

that a'torque of constant force capable of manual regulation by means of rheostats 7 and 8 is applied to the armature 4. The inde endent armature-circuit is not indispensa le, since the device may be operated with the armature-coils short-circuited, or these coils may be removed altogether.. The armature-shaft carries a lever 9, at each end of which are contacts 10 and 11', respectively adapted to' dip into mercury-cups 12 13. These cups are in 'circuits'14 15, sup lied from a suitable source 16 and-contro ing, respectively, the magnets 17 and 18, one of which controls the actuating mechanism for raising the electrode and the other of which controls the mechanism by which the electrode is lowered, so that if one of the contacts is made at the mercury-cups the electrode.

will be lowered, and if the contact is made at the other cup the electrode will be depressed in the furnace, thereby increasing or diminishing the resistance of the electrode-circuit and correspondingly diminishing or increasing the current fiowin 19 is a magnet which I show in the drawing as a solenoidmagnet.

as shown in the drawing, in a circuit with a series converter 20, by which a current of less voltage, but varying directly with the current in the main circuit, is supplied to magnet 19. This magnet has an armature 21 attached to the lever 9, which tends to draw the lever down, and thus move it in opposition to the constant force applied to it by armature 4. The motion of the lever is restricted b the post 22, having suitable stops 22. Ifbwever, if a direct current is used the de- Where an alternating current is used, it is preferably arranged, 9o

IOO

rived re ulating-current will be obtained by so that the torque of the armature will be just sufficient to counterbalance the pull of the solenoid-magnet 19 when the electrode is in proper position in the furnace and a normal current is passin through it. This will keepthe lever 9 in a h will hold both of the contacts 10 and 1 1 out of the murcury-cups, and therefore neither of the electromagnets 17 or 18 will be actuated and the electrode will remain stationary in the furnace. If, however, the electrode should be too high in the furnace, the resistance of its circuit being'increased thereby less force will be exerted through magnet 19 on the armature 21, so that'the torque of the armature 4 will overbalance the action of the magnet 19 and will move the lever so as to make contact in the mercury-cup 12 The current will thereupon flow through the magnet 18, which will cause the feeding device to move the electrode down in the furnace, thus lowering the resistance of the electrodecircuit and increasing the current whichpasses through it. When the current has reached a point high enough to exert upon the armature 21 a force sufficient to counterbalance the torque of the armature 1, it will move the lever 9 and will open a circuit at the mercurycup 12, thus dener'gizing the magnet 18 and causing the feed of the electrode to stop. llf the current passing through the electrode should increase, an increased pull will be exerted by the magnet 19, which will move the lever 9 sufficiently to make contact at the mercury cup 13. This will energize the ma net 17, which in turn will control the feeding mechanism of the electrode, so as to raise it in the furnace until it has reached a point where the current is restored to its normal condition. The force exerted by the magnet 19 will then balance the torque of armature 4, again opening circuit at 13, so that the electrode will come to rest. In this way the apparatus will respond quickly to very slight changes in the position of the elec trode and the current passing therethrough, each electrode being individually regulated by its own mechanism and all the electrodes of the furnace being kept in such positions as to maintain constant conditions'of resistance and of current in their respective circuits.

I may regulate the current which is sup plied to any electrode not only by operation of rheostats 7 and 8, but by a switch 23, by whichone of the field-coils 6 may be cut out of the circuit and the current passing through the corresponding electrode thus decreased to about one-half the quantity at which the de-V vice was originally adjusted. This is often importanteas, for example, when by reason of defective composition some of the electrodes may become unduly heated. In such case the current in these electrodes can be 6' lowered without aifecting the current passing through the other and normally acting elecorizontal position and trodes. The current may thus be regulated manually in any one or in all of the electrodes by cutting out of circuit one of the field-coils of one or all of the regulating devices.

t will be understood b those skilled in the art that the mechanism escribed above may be varied in man ways, although I deem the form which I i lustrate to be preferable. Thus instead of the solenoid-magnet 19 and the motor 4 5 other forms of electromagnetic devices may be substituted, the essential being only that the magnetic regulator by which the current is controlled is opposed by an electromagnetic device. This has great advantages over the use of a spring or a weight for the opposing force, because it can be ad justed with reat accuracy and is not subject to the distur ing influences which impair the value of adjustable springs or weights. I also find that a weight 2 1, traveling on a screw 25, attached to the lever 9, assists materially in giving a better regulation, as such adjustable counterpoise can be shifted toward or from the axis of rotation, and the opposing electromagnetic force can be slightly varied, as desired. 1 show this construction in the drawing.

The apparatus may be modified in many ways, since What I claim is 1. Means for regulating furnace-electrodes, consisting of motive devices arranged to move the electrode in opposite directions, normally open circuits for the motive devices, an electromagnetic regulating device operated by current derived from the electrode-circuit and proportional thereto, said device being arranged to control the circuits of the motive devices, and a magnetic device arranged to. oppose the action of the regulating device and energized from a separate source; substantially as described.

2. Means for regulating furnace-electrodes,

,comprising motive devices for feeding the electrode, normally open circuits for the motive devices, an electromagnetic regulating device operated by current derived from the main current and proportional thereto, said regulating device controlling the circuit of the motive devices, a magnetic device arranged to oppose the action of the said regu lating device energized from a separate source, and means for varying the force of the opposing magnetic device; substantially as described.

. 3. The combination with a' roup ofelectrodes, eath of which is provided with motive devices for raising and lowering it, of electromagnetic regulatin devices operated by current derived from t e main current and proportional thereto, each of the regulating devices being arranged to control the circuits of the motive devices of one of the electrodes,

magnetic devices energized from a separate source, and arranged to oppose the action of the first-named regul'atin devices andmeans for adjusting the orce o the opposing magnetic devices; substantially as described.

' 4. In means for regulatin furnace-electrodes, the combination .wit separate motive devices for raising and lowering the electrode, of a regulator comprising an armature and field, 1n circuit w1th a source of current v inde endent of the current to be regulated,

consisting of separate motive devices for raising and lowering the electrode, normally open circuits therefor, an armature and field in circuit with a source of currentinde endent of the current to be regulated, an electromagnetic devieeoperated by a current derived from the main current and .proportional thereto, and circuit-controlling means for the circuits pf the motive devices operated by the opposing actions of said armature and elec tromagnetic device, together with means for regulating the tor ue of the armature; substantially as descri ed.

6. A current-regulator, com rising an armature and field in circuit wit a source of current independent of the current to be regulated, normally open circuits including motive devices, a lever carried by the armatureshaft, and carrying contact devices for controlling said circuits, and an electromagnetic device operated by a current derived from the main current and proportional thereto and acting upon said lever in opposition to the armature, together with means for adjusting the force ofthe opposing actions of said armature and electromagnetic device; substantially as described. p

In testimony whereofI have hereunto set my hand.

-NORWOOD P. KEEN, GEORGE B. BARRELL.

Images