US793513A - Circuit-controlling system. - Google Patents

Description

No. 793,513. PATENTED JUNE 27, 1905.

A. O. EASTWOOD.

CIRCUIT CONTROLLING SYSTEM.

APPLICATION FILED 1120.19, 1904.

V a SHEBTSSHEET 1.

u Q, T i T jm'erahi M wi afaffivoad.

PATENTED JUNE 27, 1905.

A. G. EASTWOOD.

CIRCUIT CONTROLLING SYSTEM.

APPLICATION FILED DBO.19, 1904.

3 SHEETS-SHEET 2.

fifihaysw Alllllll "Inn" No; 798,513. PATENTED JUNE 27, 1905.

A. O. EASTWOOD.

UNITED STATES Patented June 27, 1905.

AR"HUR C. EASTWOOD, OFOLEVELAND, OHIO.

CIRCUIT-CONTROLLING SYSTEM.

SPECIFICATION forming part of Letters Patent No. 793,513, dated June 27, 1905.

Application filed December 19, 1904:. Serial No. 237,435-

To all whmn (it 717,04 concern:

Be it known that I, ARTHUR O. EASTWOOD, acitizen of the United States,residing in Cleveland, Ohio, have invented certain Improvementsin Circuit-ControllingSystems,of which the following is a specification.

One object of my invention is to provide a system including apparatus which will automatically open an electric circuit when the current-flow therein reaches or exceeds apredetermined amount or when the voltage of said circuit drops to or below a predetermined minimum. It is also desired that the system shall include apparatus which may be actuated at will from a distance for either opening or closing the circuit.

Another object of the invention is to provide a system by means of which the armature of a motor may be brought to a quick stop from any of a number of points remote from the motor-controller.

The invention further embraces means whereby the armature-circuit ofthe motor will be automatically opened upon the failure of the voltage of the supply-circuit and means whereby the system is rendered inoperative until the handle or equivalent part of the operating-controller is returned to its oil? or normal starting position.

These objects 1 attain as hereinafter set forth, reference being bad to the accompanying drawings, in which- Figure 1 is a diagrammatic view of one combination of apparatus comprising my improved system, showing it as applied to the control of a series motor. Fig. 2 is a diagrammatic view showing my system as applied to the control of a shunt-motor and including a hand-operated controller and apparatus for quickly stopping the motor, and Fig. 3 is a diagrammatic view showing my system as applied to the control of acompoundwound motor and including a reversing-controller.

One application of my invention is found in connection with conveying-bridges in which the driving-motors are located at one end of the bridge structure and operatively connected, by means of cables, to hoisting and conveying apparatus mounted on a trolley arranged to travel upon the bridge, the operator riding on the trolley and therefrom controlling the speed and direction of operation of the driving-motors.

To obviate the necessity for a large number of heavy connecting-wires upon the bridge between the controller on the trolley and the stationary motors, magnetically-operated controlling devices are usually employed, which, together with acontrolling resistance, are usually mounted adjacent to the driving-motors in the manner shown in my United States Patent No. 770,630, granted September 20, 1904. With such an arrangement of apparatus it is only necessary to run wires of relatively small section upon the bridge, and these, together with a small operating-controller on the trolley, provide the means whereby the necessary connections may be made to the magnet-coils of the magnetically-operated switches controlling the motor or motors.

For the same reasons as above noted the main circuit-breaker is usually placed adjacent to the motors, so that it frequently happens that the opening of said breaker by reason of an overload leaves the operator on the trolley without power and with no means of conveniently resetting the circuit breaker other than to climb down to the motor-house or to wait until the resetting is done by some one else. This condition usually involves considerable inconvenience and loss of time. By my improved system the possibility of this trouble is removed, since the operator is provided with means on the trolley whereby he can conveniently and quickly reset the circuit-breaker at will irrespective of the position of the trolley up )n the bridge. Means is also provided whereby the operator can instantly open the main circuit from his posi tion upon the trolley, and so cut off the current in case of accident or injury to the cables or other portions of the machine.

In various current-controlling systems em-' ploying magnetically-o 'ierated switches these latter are designed to operate within a certain range of applied voltage. If, however, the

voltage of the supply-circuit drops below a certain minimum value, the action of the switches becomes erratic, so that for the protection both of the controller and of the motors it is desirable in order to secure reliable operation of the apparatus that the circuit be automatically opened when this critical voltage is reached and, moreover, be maintained open until the voltage of, the siuiplycircuit has again risen to its proper value.

Hitherto apparatus has been provided which upon the failure of the voltage of the supplycircuit permitted a controller or rheostat arm to move to its off position under the action of a weight or spring. These devices have, however, proved unreliable by reason of the friction resulting from burned or pitted contacts, so that frequently it was found that when the voltage failed the contact-arm would stick at some intermediate point,causing burning out of the armature or of the resistance I upon the restoration of the current. Frequentl y also the sticking above noted resulted in serious delay in cases where a number of meters of large size were operated on the same circuit, since if the main circuit breaker or fuse opened and the contact-arm of one of the COI'llllOllM'S failed to return to the off position practically a short circuit was created, and all of the motors on the circuit had to remain idle till the defective instrument was found and the trouble corrected.

By my invention the above-noted objectionable conditions are obviated, and while in the figures 1 have shown said. invention employed to operate various forms of electric motors these may be replaced by other forms of current-actuated apparatus without departing therefrom.

Referring to Fig. 1, A represents the armature of a series motor having a field-winding F. S is a main switch controlling the curren tl'low from the supply-mains and has connected to one of its terminals one end of the fieldwinding F, while its second terminal is connected to the, armature A through the coil of an overload controlling switch E and a magnetically-opcrated switch S. The switch is provided with means, as a weights, whereby it is maintained in its open position as long as its actuating-coil is deenergized. The coil 0 of the switch E is provided with a movable core 0, placed so as to engage and operate a pivoted blade 0 under certain conditions of current-flow in said coil. Said blade normally connects a terminal in connection with the positive side of switch S and any number of normally closed hand-operated switches b, 7), and If, connected in series with each other and with one end of the actuating-coil a of the switch S. The opposite end of said coil is connected to one end of an auxiliary switcha, designed to be closed by a metallic piece carried upon but insulated from the blade of switch S, whose second terminal is connected to the negative side of the main switch S through a bank of resistance R. That terminal of the auxiliary switch s to which the coil s is connected is also connected to one terminal of each of any desired number of normally open switches c, c, and 0, whose second terminals are all connected together and to the negative side of the main switch S.

When my invention is used in connection with a conveying-bridge and a system such as indicated above, one each of the switches and c is placed upon the trolley, while the motor, together with switches S S and the overload-controlling device E, are placed in a suitable inclosure upon the bridge. If new it is desired to start the motor from the trolley, the main switch S is first closed, though it will be noted that such closing does not supply current to the motor, since the switch S is open, as is also the circuit of its coil. The switches c and 7) are usually of the push-button type, and if the lirst of these be closed current will flow from the positive side of the main switch S through coil 0, switch-bladew, switches b, and coil .s, thus energizing the latter and causing closure of the switch S. Such closure of this latter switch permits current to How to the motor through the various controlling mechanism, which is omitted from Fig. 1 for the sake of clcarness.

The closing of the switch S closes the auxiliary switch s, thereby rendering the current-flow through the coil a independent of the switches 0, since there is a complete circuit from the main switch S through switches 71, coil s, auxiliary switch and resistance it to the negative terminal of said main switch. Said resistance R serves to cut down,. and hence economize, the current-fl ow through the coil s, such cutting down of the current being allowable in view of the fact that much less current is required to hold the switch S in a closed position than is required to bring it to such position. if it be desired to cut off the current-supply to the motor, one of the switches 7) may be operated, with the result that the circuit including the-coil x is broken and the switch S is permitted to open, thereby breaking the main motor-circuit.

Should an overload occur on the motor, so that the currei'it-l'low thereto rises above a pre determined maximum, the core w isdrawn into the coile and made to strike and raise the. switch-blade c, with the result that the circuit of the coil .9 is opened, thereby permittii'ig the switch S to open under the action of its weight .s, as before.

Should the voltage of the suppl y-circuit fall below a predetermined minimum, the weight .v will overcome the effect of the coil upon the plunger of the switch S and said switch will open, thus opening the main motor-circuit. The restoration or rise of voltage in the circuit after such opening cannot cause the switch S to close, since, as before noted, its coil x is open-circuited by reason of the open position of the auxiliary switchx and the switches c. The closure of any of these latter IIO switches will, however, complete the circuit through the coil 5, as before noted, causing the switch S to close. It will be understood that the switches c and b can be placed at any widely-separated points, so that the operation of the switch S, and consequently the operation of the motor, may be controlled from a distance.

In that embodiment of my invention shown in Fig. 2 I have illustrated a hand-operated controller D as connected in circuit with the armature and field winding of a motor which is of the shunt type, the speed of such motor being varied by varying the amount of resistance in its armature and field circuits. The controller is provided with a movable arm (Z, having a contact-piece designed to electrically connect with each other the various segments, of which there are four sets in the presentinstance, arranged concentrically with said arm. One of the segments Cl is continuous throughout its length, which is equal to the re through which the controller-arm is to be operated, and is permanently connected to one pole of the main switch S. Upon a second are are two segments (Z and (.Z", insulated from each other, the shorter of these being so placed as to be engaged by the contact-arm of the controller as soon as it is moved from its off position, and thereby electrically connected with the segment (Z. This segment (Z is connected to oneend of the coil 8 of the'electromagnetic switch S and also to the auxiliary switch .9, operated by said first switch. The

second terminal of the switch 8 is connected above-mentioned segments includes two series of segments lyingalong difl'erent arcs or lines, the first of these series (1 having connected between them the various sections of a bank of armature resistance R and being so placed as to be engaged by the contact-piece of the arm (Z just as this latter is leaving the segment (1". The last one of the segments d is of greater length than the others, being extended so as to remain in engagement with the contact-arm of the controller as this latter is moved through the latter part of its path of motion and being in connection with one terminal of the armature A.

The second series of segments (Z includes a relatively long sectionplaced to be engaged by the contact-arm (fl as soon as this is moved from its of? position and extending to a point beyond a straight line connecting the pivot of the contact-arm and the end of the long one of the segmentsd" adjacent to the resistance R. The others of the segments (.Z have connected between them the sections of a bank of field resistance R one end of which with the long one of the segments (Z is connected to one end of the shunt field-winding f, whose opposite end is connected to the positive terminal of the main switch SQ As in the case of the arrangement of parts shown in Fig. 1, I providea series of switches 72?) b interposed between the coil 8 of the switch S and the positive terminal of switch S. I also provide a switch S and a bank of resistance R in series therewith connected between the terminals of the armatureA and employ a locking-bar L, extending between the blades of the switches S and S whereby said switches are kept from both being in a closed position at the same time. The actuatiug-coil x 01 the switch S is connected directly across the armature-terminals.

When the controller-arm (Z is in its ofi position, as shown, the circuit of the armature A is open, as are also the circuits of the coil 8,

switch S, and of the shunt field-windingf of the motor, although if it he desired that said winding shall not be open when the arm B is in this position this can be accomplished by extending the segments '(Z and (Z so that they will be connected by the said contact-armwhen in said off position.

1f the controller-arm d be moved in a clockwise direction from the position shown, the circuit of the coil 8 will be closed as soon as said arm connects the segments (1 and 612. Even though continued motion of the arm (Z causes its contacts to break engagementwith the segment (Z the circuit of the coil .9 is not open, since, as in the arrangement shown in Fig. 1, the auxiliary switch a has been closed by the closing of switch S, thus permittingcurrent to flow from the positive side of switch S through switches 7), Z), and b coil s, auxiliary switch s resistance R, segments 7) and (Z, and so to the negative terminal of the main switch.

hen the arm (Z engages the first of thesegments d", the circuit through the armature of the motor is completed and said armature should begin to revolve. As the controller-arm is moved farther forward the resistance R is gradually cut out, with a consequent increase in the armature speed, and when said arm by its continued motion cuts into circuit with the shunt-field all of the resistance R the armature is brought up to its full speed. In the meantime the coil s of switch S is excited by the electromotive force generated by the armature A and though tending to close is prevented from doing so by the IOcking-barL and the switch S. Consequently if the motor be running at full speed (or at an intermediate speed) and the voltage of the supply-circuit should fail or fall below a predetermined minimum the coil of switch S will be deenergized, so as to cause said switch'to open and cut ofi the armature A from the supply-mains. Switch S is now closed by the action of its coil, and the motor acting as a self-excited generator forces current through the resistance R, thus quickly bringing the armature to rest.

As before noted, when the switch S has once been opened it will not close upon the restoration of the current to the su pray-mains, it being necessary in the system shown in Fig. 2 to return the controller-arm (Z to its starting position, so as to electrically connect the segment (1 and d, after which the motor may he started as before. I t any of the switches 7) be opened while the motor is in operation, the circuit of the coil 8 will be broken and the braking-switch S will be automatically operated, as above noted, to bring the armature to a quick stop. As before, it is now necessary to return the controller-arm (Z to its starting position before the motor can again be set in operation. Similarly when the arm 7) is moved by hand to its oil position the circuit of the coil .9 is opened and the armature A is quickly brought to rest, it being noted in any case that the opening of the armaturecircuit upon the failure of the line voltage or upon the operation of one of the switches 7) is accomplished by the switch 8' and does not depend upon the return of the controllerarm d to its off position, as is the case in devices of this nature at present known to the art. Said switch is positively opened by the action of its weight or equivalent part, which has only to overcome the slight friction in the bearings of the switch and may therefore be depended upon to open it.

In Fig. 3 is illustrated another application of my invention, showing it as applied to a system including a compound-wound motor operated by a reversing-controller of the drum type, the speed of the motor being varied by varying the amount of the resistance R in its armature-circuit. While with this arrangement 1 have illustrated the overload-controlling device E as forming part of the system, it will be understood that it may be omitted, if desired, as in the case of Fig. 2, without all'ccting the operation of the other parts thereof. In the drum-controllerjl (shownin Fig. 3) a linger (,Z is connected to one end of the coil a, while the finger (Z like the segment (Z of Fig. 2, is connected to one terminal of the auxiliary switch N the operation of switch S being the same as previously described.

I claim as my invention 1. The combination of a current-actuated device, an electromagnetic switch in circuit therewith, and two auxiliary circuits, one including a normally open switch independent of the electromagnetic switch and the other including an auxiliary switch operated by said electromagnetic switch, each of the auxiliary circuits being connected to complete the circuit of the coil of said electromagnetic switch independently of the other, substantially as described.

2. The combination of a current-actuated device, an electromagnetic switch in circuit therewith, and two auxiliary circuits, one in cluding a normally open switch imlepemlent of the electromagnetic switch and the other including an auxiliary switch operated bysaid electromagnetic switch, both circuits being connected to complete the circuit through the coil of the electromagnetic switch indepcmdently of each other, and a bank of resistance in circuit with said auxiliary switch, substantially as described.

3. The combination of a current-actuated device, an electromagnetic switch in circuit therewith, and two auxiliary circuits for connecting the coil of said switch with a source of current-supply, a bank of resistance inonc of said auxiliary circuits, an auxiliary switch controlled by said electromagnetic switch, means for making and then breaking the first auxiliary circuit, and means for making the second auxiliary circuit before said lirst auxiliary circuit is opened, substantially as described.

4. The combination of a current-actuated device, an electromagnetic switch in circuit therewith, and two auxiliary circuits, one including a normally open switch independent of the electromagnetic switch and the other including an auxiliary switch operated by said electromagnetic switch, both circuits being connected to complete the circuit through the coil of said electromagnetic switch, with an automatic switch also connected to said coil having means for open-circuiting said coil when the current'['low through the currentactuated device exceeds a predetermined amount, substantially as described.

5. The combination of a current-actuated device, an electromagnetic switch in circuit therewith, and two auxiliary circuits, one including a normally open switch independent of the electromagnetic switch and the other including an auxiliary switch operated by said electromagnetic switch, both circuits being arranged to. complete the circuit through the coil of said electromagnetic switch, with an automatic overload-switch and a hand-operatcdswitch also in circuit with said coil, substantially as described.

6. The combination of a current-actuated device, an electromagnetic switch in circuit therewith, means tending to open said switch, an auxiliary switch constructed to be closed by the closing of the electromagnetic switch, and a hand-operated switch in shunt to the auxiliary switch, the coil of the electromagnetic switch being connected both to the auxiliary and to the hand-operated switches, substantially as described.

7. A system having a main circuit including a current-actuated device, a winding and an electromagnetic switch, an auxiliary switch actuated by the winding and a hand-operated switch, both normally closed and in circuit with Lil the coil of the electromagnetic switch, with two circuits in shunt to each other and both including means for completing the circuit.

through said coil, substantially as described.

8. A system including an electromagnetic switch and a current-actuated device, means for causing closing of said switch at will, and an auxiliary switch having a member operated by the electromagnetic switch for maintaining the circuit through the coil thereof independently of and after the operation of said closing means, substantially as described.

9. A system including a current-actuated device, a main switch therefor, hand-operated switches independent of said main switch connected to cause opening and others for causing closing of said main switch, and additional means for opening said main switch, both when the voltage of the supply-circuit falls below a predetermined minimum and when the cu rrent-flow to the current-actuated device rises above a predetermined maximum, substantially as described.

10. A system including a motor, acontroller for the same, an automatic switch in circuit with the motor-armature, said controller including a contact whereby the coil of the switch is supplied with current before the circuit of the motor-armature is completed, and means for maintaining the current flow through said coil independently of said contact after the switch is closed, substantially as described.

11. Asystemincludinga motor, acontroller for the same, an automatic switch in circuit with the motor-armature, said controller including a contact whereby the coil of the switch is supplied with current before the circuit of the motor-armature is completed,a normally closed hand-operated switch or switches also in circuit with the coil, and a circuit in shunt to the controller-contact whereby the said coil may be energized independently of said contact, substantially as described.

12. The combination of a motor, a controller therefor and an automatic switch, the coil of said switch having two branch circuits whereby it may be connected to a source of current-supply, both of said circuits passing through said controller, substantially as described.

13. The combination of a motor, a control ler therefor and an automatic switch, the coil of said switch having two branch circuits whereby it may be connected to a source of current-supply, both of said circuits passing through said controller, with means actuated by said switch for maintaining one of the circuits after the other has been opened in the controller, substantially as described.

1 1. The combination of a motor, a controller therefor, an automatic switch in circuit with the motor-armature, and an auxiliary switch actuated by said automatic switch and having a terminal connected to the coil thereof, said controller including two contacts respectively in circuit with said coil of the automatic switch and the second terminal-of the auxiliary switch, substantially as described.

15. A motor, a controller therefor, means independent of the controller for opening the armature-circuit of the motor when the voltage of the supply-circuitfalls to a predetermined point, and means, including an electromagnetic main switch and means for keeping the winding of said switch open-circuited, for preventing the restoration of current to said armature-circuit until the controller has been operated to its starting position, substantially as described.

16. A motor, a controller therefor, means independent of the controller for opening the armature-circuit of the motor when the voltage of the supply-circuit falls to a predetermined point, including an automatic switch, a contact connected thereto and so placed in the controller as to be supplied with current only when said controller is in its starting position, with means for supplying current to the winding of the switch after the controller has been operated past said starting position,

substantially as described.

17. A motor, a controller therefor, including a contact placed to be in circuit only when the controller is in its starting position, and a second contact placed to be in circuit after the controller has been operated from said position, an automatic switch in the main motorcircuit, an auxiliary switch operated by the automatic switch and in circuit with the coil thereof, said automatic switch and the coil being respectively connected to said two contacts of the controller, substantially as described.

18. The combination of a motor, an electromagnetic switch in circuit therewith, and two auxiliary circuits, one including a normally open switch and the other including an auxiliary switch operated by said electromagnetic switch, both of the auxiliary circuits being connected to complete the circuit of the coil of the electromagnetic switch, a switch for short-circuiting the armature and means for preventing said latter switch and the electromagnetic switch both being closed at the same time, substantially as described.

19. A system including an electromagnetic switch and a current-actuated device, means for causing closing of said switch at will, and means for maintaining the circuit through the coil of said electromagnetic switch independently of and after the operation of said closing means, with an automatic switch connected to short-circuit the current-actuated device and a locking-bar extending between said automatic switch and the electromagnetic switch, for preventing both of said switches being in a closed position at the same time, substantially as described.

20. The combination of an electromagnetic IlO switch, an auxiliary switch controlled thereby said terminal of the auxiliary switch, substarv having both its terminals connected to the tially as described.

same current-supply main, a normally open In testimony whereo'fl have signed my name controlling switch or switches interposed beto this specification in the presence ol two sub 5 tween said current-main and one of said terscribing witnesses.

n'iinals, with a normally closed controlling V 1 1! r switch or switches, said latter switch or ARUIUR switches and the coil of the electromagnetic \Vitnesses: switch being interposed in the connection be- E. R. LOUGHERY,

1O tween the second current-supply main and the Jos. H. KLEIN.

Images