US1515492A - Regulating device for electric furnaces - Google Patents

Description

Now 11 1924. V 1515,492-

J. KELLE HER REGULATING DEVICE FOR ELECTRIC FURNACES Filed Oqt. 16. 1919 4 Sheets-Sheet 1 Nov.

I 1515,492 J. KELLEHER REGULATING DEVICE FOR ELECTRIC FURNACES 4 Sheets-Sheet 2 Filed Oct. l6 1919 Nov; 11 1924.

J. KELLEHER REGULATING DEVICE FOR ELECTRIC ummcns Filed on. 16. 1919 4 Sheets-Sheet 3 v J. KELLEHER REGULATING DEVICE FOR ELECTRIC FURNACES Nov. 11 1924 llw-T Patented Nov. 11, 1924.

UNITED STATES JAMES KELLEHER, OF GO'DERICH, ONTARIO, CANADA.

REGULATING' DEVICE FOR ELECTRIC FURNACES.

Application filed October 16, 1919.

To all whom it may concern:

Be it known that 1, JAMES KELLEi-IER, a citizen of the Dominion of Canada, and a resident of the town of Goderich, Province of Ontario, Canada, have invented certain new and useful Improvements in Regulating Devices for Electric Furnaces, of which the following is a full, clear, and exact description.

My device relates in general to the regulation of electric furnaces and more particularly to that type of furnace in which one or more electrodes carry current to the furnace interior, thereby forming an are between two electrodes; or between an electrode and the charge containedin the furnace; or between both electrodes and the charge.

As is Well known in the art, the usual method of regulating such furnaces, so as to maintain the load carried by the furnace within given limits, is to lengthen or shorten the electric are by moving the electrodes. This may be done either by hand or mechanical means, and when the latter means are employed, electrically operated winches or hoists are usually used. WVhen such a hoist or winch is used, regulation is obtained by reversing the direction of rotation of the motor controlling such winch or hoist, or by operating suitable clutches controlling the hoist. The reversal of the motor or operation of the clutches may be controlled manually or automatically.

I have found that in order to regulate an electric furnace, at least the two following conditions must be contended with: First, when the are or arcs of the furnace are lengthened or shortened by changing the positions of one or more electrodes, the current flowing through the furnace commences to vary at first rapidly and then gradually at a less rapid rate until an apparent equilibrium has been attained, the time for this change varying with the size of the furnace or its charge; second, a furnace may run, within given limits of regulation, for a considerable length of time, but a violent reaction in the charge or a sudden quenching of the are due to the charging of raw material will cause a rapid increase or decrease in the flow of current through the furnace.

As both the above named conditions may be found separately or combined in any one furnace, I have sought to provide a device which shall adequately contend with these Serial No. 330,957.

conditions. My invention has, therefore, for its general objects to provide a device of such a nature as to control the electrodes so that they may be moved at a gradually decreasing speed, depending upon the type of furnace, charge, etc., until regulation is complete; to provide a device which shall regulate the current, passing through the furnace, within more or less definite limits under normal operating conditions; and to provide a device which shall control the operation of the electrodes so that they will be moved rapidly in the required direction under such conditions as short-circuit, broken arcs, or heavy reactions.

Moreover, my invention is of such a nature that the measuring or metering element thereof is brought back to its neutral position when the motor circuit controlling the electrodes is closed; and, since the measuring element is damped by an inverse time element, such as a dash pot, the length of time for the measuring element to again close the circuit will depend largely u on the forces acting in the device, or, in 0t ier Words, upon the amount of current passing through the furnace in excess of the given limits of regulation. This produces the desired gradual decrease in speed at which the electrodes are operated.

Furthermore, the measuring or metering element of my device is controlled by a variation of voltage, amperage or Wattage, and is of such a nature that when the electricity passing therethrough exceeds the predetermined limits in either direction, an electric circuit will be closed which will operate relays and thereby close the regulating motor circuit for a given length of time only, and at given intervals of time until. the current is within the predetermined limits of regulation.

If the intermittent action of the motor is not suflicient to take care of abnormal changes in the current, my device is so designed that a high speed regulation is obtained by the provision of an additional contact, which is closed when the metering element of the device is moved to its maximum position by a given amount of variation from the normal. By the maximum movement of this metering device a number of relays are operated to prevent the time element of the device from acting and also to prevent the contact making element of the device from returning to its normal position. The closing of this additional contact allows the motor to rotate continuously in the required direction until the current passing through the furnace comes within the limits of the intermittent regulation above referred to, which will continue until the regulation is complete.

The above objects and advantages have been accomplished by the device shown in the accompanying drawings, of which:

Fig. 1 is a side elevation of my complete device.

Fig. 2 is a plan view of the same.

Fig. 3 is an end elevation of the device showing the metering element thereof.

Fig. 4 is an end elevation of the device showing the time element thereof.

Fig. 5 is a diagrammatical view of my device in connection with a furnace and a motor for operating the same, and shows the electrical connections between these devices.

Fig. 6 is a diagrammatical view of an alternating current three-phase motor with fragmentary portions of the electric circuits.

Fig. 7 is a similar View showing an alternating current two-phase motor.

My device comprises in general a metering element, a time element, and a plurality of relays, controlled by the metering element and the time element.

Referring to Figs. 1 to inclusive, 9 is the base and 10 is the body of the device. The body 10 is preferably in the form of a hollow casting and has a plate 11 secured to the bottom thereof. The casting and plate forms a magnetic path for the motor switch relays 1.2 and 13, the time element relay 14 and the cut-out relay 15. These relays are all preferably of the solenoid type. Each of the relays is, of course, provided with the well known winding 16 and solenoid core 17. Each solenoid core carries suitable rods 18 for the contact discs 19 of the relays. The discs 19 are yieldably mounted upon the rods 18 in a well known manner. The motor relay 12 has four pairs of contacts 20 and 20, 21 and 21, 22 and 22, and 23 and 23. The contact 20, 20, 21, 21, 22 and 22 are circuit closing contacts and contacts 28 and 23" are circuit opening contacts. The motor relay 13 is similarly provided with four pairs of contacts 2 1 and 24 25 and 25. 26 and. 26", 27 and 27. The contacts 24:, 24% 25. 25, 26 and 26 are circuit closing contacts and contacts 27 and 27 are circuit opening contacts. The time element relay 14 is provided with two pairs of contacts 28 and 28 and 29 and 29, both circuit closing contacts. The cut-out relay 15 is provided with but one pair of contacts 30 and 30, which are circuit opening contacts.

At one side of the body 10 of my device is mounted the metering element 31. which comprises a solenoid 32 through the winding of which a proportionate amount of the our rent supplied to the furnace passes. 33 is the core of the solenoid which is provided with an upwardly extending rod 34:. Carried at the upper end of the solenoid 32 is a plate of insulating material. This plate is secured to the solenoid by any suitable means, but preferably by a suitable locked nut 36. Two standards 37 are carried by the plate 35, and a plate 38 is mounted on the upper end of the standards and is arranged parallel to the plate 35. The plate 58 is also of insulating material. A standard 39 is arranged at the extreme outer end of the plates, whereby they are rigidly supported. 40 is a beam which is pivotally mounted between the standards 37 and provided preferably with a spiral spring at, which counterbalances the forces acting in the solenoid and keeps the beam substantially in its normally neutral position. The outer end of the beam -10 is pivotally united with the upper end of the rod 34 of the solenoid core, so that the beam will be controlled by the operation of this core. Gontact springs 42 and 43 are carried, respectively, between insulating plates and 38. Contacts 141. and 45, respectively, are carried at the outer ends of these springs. A double sided contact a6 is mounted in the beam and engages with either of the, contacts 4A or 45. Adjusting screws 47 are carried by each of the plates 35 and 38 and engage with the springs 42 and 43, whereby their positions may be adjusted. A contactscrew 48 is carried by the late 38 and is so disposed that it is engageiiile by the contact 14. Likewise a contact screw 49, carried by the plate 35, is engageable with the contact 45. 50 is an armature rod which is carried by the outer end of the beam 10 and is movable between the ends of the U-shaped core 56 of an electro-magnet 51. This magnet is mounted between the plates 35 and 38 and, when energized, the beam 40 will be returned to its normal. position. 52 is a dash pot. which is concentrically arranged beneath the solenoid 31. It comprises a casing 53, preferably filled with oil or other suitable liquid, and a central stem 54, which is connected with the lower end of the solenoid core 33. A disc 55 is carried at the lower end of the stem 5% and is immersed in the oil of the dash pot. The disc 55 may be provided with one or more holes as is customary in devices of this character. The dash pot acts as a damping device to the small and sudden variations in the current passing through the solenoid 31 and also to the continuous variation set up by the alternating flux.

At the end of the body 10 opposite the metering element, is the time element of my device which comprises a bracket 61 secured to the body 10 and provided with two oppositely arranged pivot screws 62. R0-

tatably mounted between these screws is a shaft 63, having a concentric time Wheel 64.- rigidly mounted thereon. This wheel is provided with a spider and with a stop 66 on its outer periphery. lVhen the wheel is at rest, the stop 66 thereof is in engagement with a stop pin 67 carried by the base 9. A rigidly mounted spring 68 bears against the stop 66 and provides a wiping contact therewith, as well as preventing the rebound of the time wheel due to the engagement of the stop with the stop pin 67. lVhen the stop is in engagement with the stop pin an electrical contact is made. Adjustably mounted upon the time element shaft 63 is a circuit breaking device comprising a plurality of adjustably mounted contact rings 69,, 70, 71 and 72. The surface of the ring 69 forms a continuous electrical contact while the surfaces of the rings 70, 71 and 72 are insulated so that only a portion of their peripheries form electrical contacts. Each of the rings 70, 71 and 72 has an adjusting flange 73 rigidly attached thereto. Each of these flanges has a notched periphery, and all are locked in their adjusted positions by means of a spring 74. This spring is rigidly carried by the spider 65 of the wheel 641 and extends over the discs 78 with which it has spring engagement. lVhen adjusting the discs the spring is raised, and after the adjustment is made, the spring will engage with the notches, thereby locking the discs and connected rings in their adjusted position. A knurled nut 7 is screw threaded to the end of the shaft 63, and by means of this nut and a lock washer 76, the rings 70, 71 and 72 may be further locked in position. The rings 69, 7 0, 71 and 72 are provided with brushes 83, 84, 85 and 86, respectively. These brushes are carried by an insulated block 87 mounted on the base 9. The rings 69, 70, 71 and 72 are connected together, electrically and to the wheel 64.

The time wheel 64: is caused torotate by means of a solenoid 77, carried by the bracket 61. A crank pin 78 is carried by the spider 65 and is connected to the core 79 of the so lenoid by means of a helical spring 80. Also connected with the crank pin 78 is one end of a spring 81. The other end of this spring is adjustably attached to the bracket 61 and its action is to oppose the action of the spring 80 and to return the stop 66 of the time wheel to its position of engagement with the stop pin 67 when the solenoid 77 is ale-energized. The core 7 9 of the solenoid is provided with a longitudinal slot 82, and the spring 80 is so connected with this end of the core, that the core will be free to move down Within the spring upon being released with out exerting any great pressure upon the spring. A rod 88 is attached to the upper end of the solenoid core 79 and passes through the upper end of the solenoid and the bracket 61, Where it is provided with a nut 89. This nut may be adjusted soas to limit the downward motion of the solenoid core.

Reference is nowmade to Fig. 5 where the furnace, motor, controlling switches, and my device, together with the complete electrical circuits are all shown in a diagrammatical manner. No attempt has been made to show anything in detail, as the furnace, motor and controlling switches are Well known to those skilled in the art. In this figure is the furnace, shown with one electrode 101. 102 are the feeders for carry ing electric current to the furnace. 103 is a D. C. motor for operating the electrode. This motor is connected in any well known manner; and for clearness of illustration,

I have shown the connection as comprising pulleys 104, drum 105 and cable 166. 107 is the armature of the motor; 108 and 109 the brushes thereof; and 110 the field winding.

118 and 119 are the motor operating contactor switches of the motor 103. These switches are mechanically connected by means of an interlocking mechanism 120, whereby both switches will be prevented from operating at the same time. The

switches are for operating the motor in either direction and the interlocking mechanism therefor is well known to those skilled in the art and, therefore, shown only in diagram. 11a and 1141, and 116 and 116 are the contacts of the switch 118; and and 115, and 117 and 117 are the contacts of switch 119. 111 are the D. C. feeders, carr 'ing direct current to the motor and they are connected directly with the field 110 thereof. One of these feeders is connected by means of the lead 112 to the contacts 111 and 115*. The other feeder is connected by means of lead 113 .to the movable contacts 116 and 117. The contacts 115 and 116 are connected with the brush 108 by means of the lead 121; and the contacts 111 and 117 are connected with the brush 109 by means of the lead 122. Short- circuit contacts 123 and 123 and 12% and 124: are con trolled, respectively, by the switches 1.18 and 119. A lead 125 connects the contact 124 with the brush 108 through the lead 121, and the contact 12% is connected with the contact 123 by means of the lead 126. The contact 123 is connected with the brush 109 'hrough the lead 122 and through a braking resistance 127. The contacts 123, 123, and 12st, 1241 are closed when the motor is idle or after the switches 118 or 119 have shut off the current therefrom, whereby a shortcircuit, through the braking resistance, is provided across the brushes of the motor armature, causing the armature to come quickly to a stop after the contactors have disconnected the current.

lllll 130 is a hand controlled switch, whereby the electrode 101 of the furnace may be moved up or down by hand or may be moved to connect my device so as to automatically control the motion of the electrode. This switch is provided with contacts 131 and 131 and 132 and 13.4 for moving the electrode upwardly or downwardly, respectively. Contacts 133 and 133 are also provided for connecting the furnace with my automatic control.

134 and 135 are the A. C. feeders for controlling the switches 118 and 119 and the relays and other parts of my device. The feeder 134 is connected to one s'de of each of the switches 118 and 119; and the feeder 135 is connected with contacts 20 and 24 of the motor relays 12 and 13, respectively. Leads 136 and 137 connect the other sides of the switches 118 and 119, respectively, with contacts 20 and 24, respectively. The feeder 135 is connected with contacts 131, 132 and 133 of the hand controlled switch 130 by means of lead 129. The contact; 131 is connected with the lead 136 by means of a lead 138; and contact 132* is connected with lead 137 by means of lead 139. The contact 133 is connected with the feeder 134 through a low voltage transforn'ier 146 by means of leads 141 and 142. Thus, with the arm of the hand controlled switch connected across the contacts 133 and 133, my device will be connected with the A. C. feeders through the low voltage transforn'ier 140.

143 is a series transformer which takes a proportionate amount of current from the furnace feeder 102, and it is connected directly with the solenoid of the metering element 31 of my device, whereby the solenoid will be controlled proportionately, by the amount of current being supplied to the furnace. 144 is a load control rheostat which is connected in parallel with the series transformer and the metering element, thereby providing a shunt across these two devices. By means of this rheostat the relative amount of current passing through the solenoid 32 may be easily controlled. It will be clear, that as the resistance in, this rheostat is increased, the amount of current passing through the solenoid will also be increased, and as the amount of resistance is decreased, more current will be allowed to pass through the resistance and, therefoie. less will pass through the solenoid.

The circuits of my device are as follows: One side of the low voltage transformer is connected with the brush 83 of the time element 60 of my device, by means of the lead 150. The other side of the low voltage transformer is connected with one side of the electro-magnet 51 of the metering ele ment by means of leads 151 and 152. The other side of the electro-magnet 51 is connected with contact 28 of time element relay 1.4 by means of the lead 153. The contact 28 of this relay is also connected with one side of the solenoid 77 of the time element by means of the lead 154. The other side of the solenoid 77 is connected with lead 151, coming from the low voltage transformer 140 by means of the lead 155. Contact 28 of time element relay 14 is connected with lead 150 by means of lead 149. The lead 151 is connected with the cut-out relay 15 by means of the lead 156 and also to the contact 30 of this relay. The other side of the cut-out relay 15 is connected by means of the lead 157 to the contacts 48 and 49 of the metering clement. These contacts 48 and 49 are connected together so that when the circuit is closed through either one of them, the relay 1.5 will be operated.

The contact 90 of the time element wheel 64 is connected to the beam of the metering element by means of a lead 158, and also with the contacts 22 and 26 of the motor relays 12 and 13, respectively, by means of the leads 159 and 160, respectively. The brushes 84, 85 and 86 of the time element are connected, respectively, with the contacts 21, 25 and 29 of the motor relays 12, 13 and the time element relay 14, respectively, by means of leads 161, 162 and 163, respectively. Contacts 44 and of the metering element are connected respectively with contacts 23 and 27 of the motor relays 12 and 1.3, respectively, by means of the leads 164 and 165, respectively. One side of each of the motor relays 12 and 13 is connected with the lead 152 by means of leads 166 and 167, respectively. The other side of the motor relay 12 is connected with its contact 21 by means of the lead 168 and also to the contact 27 of the relay 113 by means of the lead 169. The other side of the motor relay 13 is connected with its contact 25 by means of the lead 170 and also with the contact 23 of the motor relay 12 by means of the lead 171. The contact 22 of the motor relay 12 and the contact 26 of the motor relay '13 are connected together by means of the lead 172. These contacts are also connected with one side of the time element relay 14 by means of the lead 17 and with the contact 29 of this relay by means of the lead 174-. The other side of the time element relay '14 is connected with contact 39 of the culout. relay 15 by means of the lead 175.

In Fig. 6 of the drawings, 1 show diagrammatically a three phase motor for controlling the electrode and the electrical connections therewith. In this figure, the motor switches 118 and 119 with their cont acts 114, 114 116, 116, 115, 115, and 117 and 117 and their electrical connections to the motor relays 12 and 13 and to the A. (l. feeders and hand controlled switch are identical with those shown in Fig.5 and herein before described. 183 is a threephase A. C.

motor, suitably connected with means for controlling the motion of the furnace electrode. Terminal 184 is connected with the contacts 114 and 117 and terminal. 185 of the motor is connected with contacts 116 and 115. When an A. C. motor is used, dynamic braking cannot be utilized and with these motors a magnetic brake must be provided. 186 shows, in a diagrammatical manner, the coil of such a magnetic brake. The coil 186 is connected with the motor terminals 184 and 185. 187, 188 and 189 are the A. C. feeders, and carry, respectively, phases A, 13, and C, of the three-phase current. The feeder 187, carrying phase A, is connected with the motor terminal 190; feeder 1S8, carrying phase B, is connected with the contacts 117 and 116 and the feeder 189, carrying phase C, is connected with the contacts 115i and 114 In Fig. 7, where a two-phase motor is shown, 191 represents the motor having terminals 192, 193, 194 and 195. 196 and 197 are the feeders for phase D, and 198 and 199 are the feeders for phase E. The feeders 196 and 197 are connected, respectively, to the terminals 195 and 194 of the motor. The feeder 198 is connected with the contacts 117 and 116 and the feeder 199 is connected with the contacts 115 and 114. All the other contacts and circuits used in connection with a two-phase motor are the same as those used in connection with a three-phase motor or a D. C. motor as shown in Figs. 6 and 5, respectively and hereinbefore described.

When my device is to be used to automatically control the movements of the electrodes of a furnace the load control rheostat 144 is so regulated as to control the amount of current passing through the solenoid 32 of the metering element so that the beam 40 of this element will remain substantially central between the contacts 44 and 45 when the predetermined amount of current is passing through the furnace. The hand controlled switch is now set so that contacts 133 and 133 thereof will be connected together, whereby my device will be connected in circuit and automatically control the movements of the electrodes of the furnace.

Vith the parts of the apparatus set as just above described, small and not violent fluctuations of the load or current passing through the furnace are automatically taken care of by my device in the following man- 1161. I

When the fluctuations in the amount of current passing through the furnace are sufficient to operate the solenoid 32 in either direction the beam 40 of the metering element will be moved in either direction and will contact with either of the contacts 44 or 45, For example, let it be assumed that the contact pin 46 of the beam 40 engages with contact 44, whereby motor relay 13 will be operated. As the time element wheel 64 is at rest with the contact 90 closed, currentwill now flow over an energizing circuit and pass from the low voltage transformer 140 to the contact 46 through lead 150, brush 83, time element wheel 64, contact 90 and lead 156. The current, from contact 44, Will flow back to the low voltage transformer through the lead 164, normally closed contacts 23 and 23 of motor relay 12, lead 171, through motor relay 13, lead 167 lead 152, and lead 151. This will energize the motor relay 13 and cause the closing of its contacts 24 and 24, and 25", and 26 and 26 Its contacts 27 and 27 will be opened. lVhen contacts and 24 have been closed, current from the A. C. feeder 134 will flow through motor switch 119 and return to the feeder 135 through lead 137 and contacts 24 and 24 When the switch 119 is operated the shortcircuit contacts 124 and 124 are opened, thereby removing the braking resistance on the armature of the motor. By the operation of switch 119, the contacts 115 and 115, and 117 and 117 will close the motor circuit through leads 121 and 122, causing the motor to be rotated and the electrode lowered, in the present case. Such motion will continue until it is interrupted by the other parts of my device. The closing of contacts 25 and 25 establishes a circuit, through the time element of my device, which is in parallel with that of the contacts 44 and 46 of the metering element. lVhen the contacts 25 and 25 are closed, current will flow over a maintaining circuit and pass from the low voltage transformer through lead 150, brush 83, brush 85, lead 162, contacts 25 and 25. lead 170, the winding of relay 13 and leads 167, 152 and 151 back to the transformer. It will thus be seen that motor relay 13 Will remain energized, even though the contacts 46 and 44 are opened. When the contacts 26 and 26 of motor relay 13 are closed, the time element rela 14 is energized, and an energizing circuit is established from the low voltage transformer through lead 150, brush 83, time element wheel 64, contact 90, leads 158, 159 and 160, contacts 26 and 26, leads 172 and 173, the winding of time element relay 14., lead 175, normally closed contacts 30 and 30 of cut-out relay 15 and lead 151, back to the transformer 140, thereby energizing time element relay 14. With the operation of time element relay 14, the contacts 28 and 28 and 29 and 29 are closed. When contacts 29 and 29 are closed, a maintaining circuit is completed through the time element, which will keep the time element relay 14 in its operative position even though motor relay 13 moves to its open or inoperative position, the current to time element relay 14 passing from the low voltage transformer through lead 150, brush 83,

loo

' 1 brush 86, lead 163, contacts 29 and 29, leads 174 and 173, through the winding of the time element relay 14;, lead 175 and normally closed contacts and 30 of cut-out relay 15, lead 151, back to transformer 140. When the contacts 28 and 28 of time element relay 1% are closed, the solenoid T7 of the time element of my device will be energized and the time clement operated. Current will flow from the low voltage transformer through leads 150 and 141.9, contacts 28 and 28, lead 154:, the winding of solenoid 77, returning to the transformer through leads 155 and 151. lVhen the solenoid of the time element is energized, it will cause the rotation of the wheel 64 and in doing so will place the springs 80 and 81 (Fig. 1) under tension. When contacts 28 and 28 are closed, the electro-magnet 51 of the metering device will also be energized by the closing of a circuit formed by leads 150 and 1419, contacts 28 and 28, lead 153, the Winding of the electro-inagnet 51 and leads 152 and 151. \Vhen this circuit is completed and the electro-magnet 51 is energized, the beam 40 of of the metering device will be returned to its neutral position and the engagement of contacts 4c and 14: will be broken. Even though the circuit through motor relay 13 is opened by the breaking of this contact, the relay is maintained in its energized position by the parallel circuit through its contacts 25 and 25 hereinbefore described. The electro-1nagnet 51 and the solenoid 77, being controlled by the same pair of contacts (viz, 28 and 28) they will operate substantially simultaneously, so that the contact made by the beam 40 and the time element wheel contact at 90 will. be broken about the same time. The controlling influence of the solenoid 32 of the metering element thereby becomes ineffective and the relays are controlled solely by the time element. It is clear that during the energization of the solenoid 77 of the time element, the electro-magnet 51 will hold the beam in the neutral position. As the time element wheel 64 rotates, the contact rings carried thereby will also rotate and the circuits passing through the brushes of this element are opened in the order in which the contact rings have been previously set. When the circuit through the brush is opened, the motor relay 13 will be tie-energized and allowed to move to its open position. This will open contacts 24 and 24 thereby cutting ofl the current to the switch 119. As this switch is opened, the short-circuit contacts 124 and 124% are simultaneously closed which will cause a shunt across the armature of the motor, and the current generated by the spin of the motor will pass through the braking resistance and thereby stop the motor by its dynamic action. In the case of an A. C. motor, suitable circuits are opened which cause the motor to come to a stop by means of a magnetic brake. By means of this braking method, the operation of the motor is continued for a definite time only. As hereinbcitore described, the engagement of contacts 29 and. 29 of time element relay le will lock this relay in its closed position even though the circuit through motor relay 13 is broken. This will keep contacts 28 and 28 in engagement, thereby allowing the solenoid T7 to continue its operation until the circuit through brush 86 is broken by such continued operation. lVhen this circuit is broken, time element relay 1 1 will be deenergized. The solenoid 77 will also be deenergized and the spring 81 of the time element will draw the time wheel. 64 back to its normal position where its stop 66 will engage with the stop pin (57 and close the contact 90. ll? the regulation of the elec trode has not been completed through one operation of the device, the contacts 46 and 44. will again engage and cause the same cycle oi? operation as just described. This will continue until the current passing through the turnacc has reached a substantial equilibrium.

hereinbetore pointed out, when the arc of the furnace is lengthened or shortened. the current flowing through the furnace commences to vary, at. First apidly and then gradually at a less rapid rate, until an equilibrium has been attained. Successive ii'itern'iittent movements of the electrodes controlled by my device will be made during predetermined intervals of time, but the periods of time between movements will vary to compensate for the varying rate of abnormal current passing through the furnace. This is taken care of by the dash pot 52 which provides an inverse time element and clamps the movement of the solenoid 32. It will be clear that the greater the variation of current passing through the furnace, above the predetermined amount, the stronger will be the force exerted in the solenoid: and the more nearly the current approaches the predetermined point, the weaker will be the force exerted in the solenoid. For this reason, the solenoid will act quickly or slowly depending upon the strength of current passing theretln'ough. As the current approaches the predetermined point. the element of time between the successive inter mittent cycles of operation will be increased, whereby the electrodes will he moved through equal predetermined distances at varying frequency.

The operation of the device as above described takes care of only slight fluctuations in the current passing through the furnace and solenoid hen, however, heavy over-loads or under-loads, are caused by reactions in the furnace, short-circuits or breaking of the arc, the contact pin 46 will lho lilfi contact first with, for example, contact 44., and as the amount of current is sutiicient to overcome the resistance of the spring 42, (Fig. 1), the contact 1d will. be moved up against the contact 48, so that the contact pin 46 of beam 40 Will be connected directly with contact 18. This action Will operate the motor relay 18 as hereinbefore described, except that time element relay 1 1 will not be energized by the closing of contacts 26 and 26*, because by the engagement of contacts 16 and 48 the cut-out relay Will be energized and therefore the normally closed contacts and 30 thereof will be opened. hen these contacts are opened, current, of course, cannot pass through time element relay 1 1. The circuit Which energizes cutout relay 15 is completed through lead 150-, brush 83, contact 90, lead 158, beam 10, contacts 16 and (18, lead 157, the winding of cutout relay 15, and leads 156 and 151 back to transformer 1 10. lVhen the time element relay lat remains inactive, its contacts 28 and 28 will, of course, remain open and the electro-magnet 51 and solenoid 77 Will remain inactive. The beam Will not then be returned to its normal position and the time element Will not be operated. The electro-magnet and the solenoid just referred to will remain ole-energized until such time as the variation of the load has reached a point Where it can be taken care of by the device as first described. When this amount of variation is reached, the contact 16 Will be disengaged from the contact 48 by the pressure of the spring 42, thereby de-energizing cut-out relay 15 and closing its contacts 30 and 3U and allowing a circuit to be established as hereinbetore described, through time element relay 1 1. The device will then act thro'iigh the time element to control the slight variations, as hereinbefore described.

It is obvious that When the motor relay 13 is operated by a heavy underload, the motor switch 119 Will be closed and the motor will be operated just as when the device is operating tor a slight fluctuation with the creep tion that the operation of the motor will be continuous because the time element is made inactive by the operation of cut-out relay 15.

It will be clea r that when the load passing through the furnace fluctuates above the normal, that the solenoid 32 will brin the contact 46 of the beam 4:0 into en dent with the contact This will energize rotor lay 12 through a circuit formed by lead 19.), normally closed contacts 27 and 27 of motor relay 13, lead 169. the Winding of motor relay 12, lead 166, leads 152 and 151. through the low voltage transformer, is 150, the time element and lead 1553. back to tile contact 46 of the h -.am -40. When the motor relay is energized its contacts and 20, and 21 and 22 and 22" are closed, while its contacts 23 and 23 are opened. The closing of contacts 20 and 20 operates the motor switch 118 and short-circuit contacts 123 and 128 in a manner exactly like the operation of switch 119 and coi'ltacts 12d and 12 1 which are controlled by themotor relay licroinliietore described. The closing of contacts E21 and 2.1. closes a circuit \vhicl'i is parallel to the circuit established by the closing of contacts 16 and from the transformer 1410 through lead 150, brushes 8-3 and 84, lead 161, contacts 21 and 21, the winding of mo- 12, leads 166, 152 and 151, back to the tra? dormer. The closing of contacts 22 and 22 energizes the time element relay 1 1 through a circuit formed by lead 150, brush 83, contact 90, leads 158 and 159, contacts 22 and 22, leads 142and 173, the Winding of time clement relay 14, lead 175, contacts 30 nd 30 oi? cut-out relay 15 and lead 151. The actuation of the time element relay 1 1 and the cut-out relay operates in the same manner and closes the same circuits as when controlled by motor relay 13 hereinbefore described. lVhen relay 12 is energized, cur' rent trom the A. G. feeders 134 and 135 will flow "through contacts 20 and 20 of this relay and the operation of the switch 1 This will close the motor circuit 1 lo. through contacts 114: and 114?, 116 and 116" and leads 121 and 122, causing the motor to rotate in the direction which will raise the elect rode out of the furnace.

The operation 01 my device in connection with the three and two-phase motors dia FY2111:l'lltttiCfllly shown in F 6 and 7, re?- spect-ively is identical. wi'tlrthat hereinbcfore des rihed in. connection with the D.-(l. inmatically shown in Fig. 5. 1e dynamic brake used in coni i the D. (l u'iotor, a magnetic re is used as shown diagrarnmatieally at 126 in these two figures. u

Obviously some modifications of the details herein shown and described may be made Without departing from the spirit of my inventionor the scope of the appended claims; and I do not, therefore, Wish to be limited to the exact embodiment herein shown and described. the form hereinbefore described being merely a preferred embodimoot thereo't.

Having thus described my invention. What 1 claim is:

1. A rgulati U device for electric fnrnaces oomprisn g a plurality of relay s, means For energiring the relays, means for locking the relays in their energized positions. and a time element for deener'gizing the relays at predetermined intervals. 2

27 A regulating device for electric furnaces comprising a metering element, controlled by the current passing through the arc of the furnace, a plurality of inlays. energized by the metering" element, and a time element for de-energizing the relays at predetermined intervals.

3. A regulating device for electric furnaces comprising a metering element, the metering element comprising a solenoid, a movable contact making beam controlled by the solenoid, and magnetically operated means for returning the beam to a given position.

4. A regulating device for electric tturnaces comprising a metering element, the metering element comprising a solenoid, a movable beam controlled by the solenoid, contacts carried by the beam, movable contacts carried in the path of the contacts mounted on the beam, and stationary contacts cngagcable with the movable contacts.

5. A regulating device for electric furnaces comprising a metering element, the metering element comprising a solenoid, a movable beam controlled by the solenoid, contacts carried by the beam, movable contacts carried in the path of the contacts mounted on the beam, stationary contacts engageable with the movable contacts, and magnetically operated means for returning the beam to a given position.

6. In an electric furnace, the combination with its electrodes and a motor, of means for intermittently operating the electrodes comprising means controlled by the current passing through the arc of the furnace comprising a solenoid and a plurality of con tacts controlled by the solenoid, and means controlling the movements of the electrodes, whereby their positions are changed, through. equal predetermined distances at varying intervals of time.

7. In an electric furnace, the combination with its electrodes and a motor, of means for intermittently operating the electrodes comprising means controlled by the current passing through the arc of the furnace comprising a solenoid and a plurality of contacts controlled by the solenoid, means controlling the movements of the electrodes, and a dash pot for regulating the movements of the solenoid, whereby the electrodes are moved through equal, predetermined distances at varying lengths of time.

8. In an electric furnace, the combination with its electrodes and a motor, of means for controlling the length of time during which the electrodes are moved. comprising a time element, motor switch controlling relays, time element controlling relay, and suitable electric connections between the several elements named.

9. In an electric furnace, the combination with its electrodes and a motor, of means for controlling the length of time during which the electrodes are moved, comprising a time element, motor switch controlling relays, time element controlling relays, a cutout relay, and suitable electric connections between the several elements named.

10. In an electric furnace, the combination with its electrodes and a motor, of means for controlling the length of time during which the electrodes are moved comprising a time element, motor switch con trolling relays, a time element controlling relay. means for controlling the length of time between the successive movements of the electrodes. and suitable electric connections between the several elements named.

11.. In an electric furnace, the combination. with its electrodes and a motor, of means for controlling the length of time during which the electrodes are moved comprising a time element, motor switch controlling relays, a time element controlling relay, a metering element comprising a movable beam. contacts carried by the beam, movable contacts carried in the path of the contacts mounted on the beam, stationary contacts engageable with the movable contacts, and suitable electric connections be tween the several elements named.

12. In an electric furnace, the combina tion with its electrodes and a motor, of means for controlling the length of time during which the electrodes are moved comprising a time element, motor switch controlling relays, a time element controlling relay, a cut-out relay, a metering element comprising a movable beam, contacts carriedby the beam, movable contacts carried in the path of the contacts mounted on the beam, stationary contact-s engageable with the movable contacts, and suitable electric connections between the several elements named.

13. In an electric furnace, the combination with its electrodes and a motor, of means for controlling the length of time during which the electrodes are moved comprising a time element, motor switch controlling relays, a time element controlling relay, a metering element comprising a movable beam, contacts carried by the beam, movable contacts carried in the path of the contacts mounted. on the beam, stationary contacts engageable with the n'iovable contacts, suitable electric connections betwcen the several elements named, and magnetically operated. means for returning the beam to a. given po sition.

14. In an electric furnace. the combina tion with its electrodes and a motor, of a time element for controlling the length of time during which the electrodes are moved. a time element relay for operating said time element, and a cut-out relay for interrupt ing the current passing through the time element relay, whereby the time element is made inactive and the electrodes are continuously moved during heavy reactions.

15. In an electric furnace, the combination with its electrodes and a motor, of a solenoid controlled by the current passing through the arc of the furnace, contacts controlled by the solenoid, an electro-magnet for opening the contacts, a. time element, a time element relay for operating the time element and for controlling the electro-magnet, and suitable electric connections between the several elements named.

16. In an electric furnace, the combination with its electrodes and a motor, of a solenoid controlled by the current passing through the arc of the furnace, contacts controlled by the solenoid, an electro-magnet for opening the contacts, a time element, a time element relay for operating the time element and controlling the electro-magnet, and a cut-out relay for interrupting the current passing through the time element relay, whereby the electroma-gnet and the time element Will be made inactive during heavy reactions in the furnace.

17. A regulating device for electric furnaces comprising a plurality of relays, energizing circuits for the relays, and maintaining circuits for the relays, the maintaining circuits being independent of the energizing circuits.

18. A regulating device for electric furnaces comprising a plurality of relays, energizing circuits for the relays, maintaining circuits for the relays, the maintaining cir- (suits being independent of the energizing circuits, a time element connected with the relays, and means for causing the actuation of the time element, whereby the maintaining circuits are opened and the relays de-energized.

19. A regulating device for electric furnaces comprising a plurality of relays, ener gizing circuits for the relays, maintaining circuits for the relays, the maintaining circuits being independent of the energizing circuits, a time element, connected with the relays, comprising a solenoid for actuating the element, and commutator means for opening the relay maintaining circuits.

20. A regulating device for electric furnaces comprising a plurality of relays, energizing circuits for the relays, maintaining circuits for the relays, the maintaining circuits being independent of the energizing circuits, a time element, connected With the relays, comprising a solenoid for actuating the element, and mechanical means for resetting the element.

21. A regulating device for electric furnaces comprising a plurality of relays, energizing circuits for the relays, maintaining circuits for the relays, the maintaining circuits being independent of the energizing circuits, a time element, connected With the relays, comprising a solenoid for actuating the element, mechanical means for resetting the element, and commutator means for opening the relay maintaining circuits.

22. In an electric furnace, the combination with its electrodes and a motor, of

means for intermittently moving the electrodes during predetermined durations of time, and at a varying frequency, comprising' a metering element, the metering ele ment having a solenoid, a plurality of con tacts and a resetting electro-magnet, a time element, and a plurality of relays controlling the time element and the resetting electromagnet.

In testimony whereof, I have hereunto signed my name.

JAMES KELLEHER.

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