US1373846A - Controller for electric motors - Google Patents

Description

H. L. VAN VALKENBUG. CONTROLLER FOR ELECTRIC MOTORS.

. APPLICATION FILED NOV.2!| 1918.

Patented Apr. 5, 1921.

Invenior [2 67772072, l ZznVzZjfivzag :5 )4

y @Aww UNITED STATES PATENT OFFICE.

HERMON L. .VAN VALKENBURG, 0F MILWAUKEE, WISCONSIN, AS$IGNOR TO INDUS- TRIAL CONTROLLER COMPANY, OF'MILWAUKEE, WISCONSIN, A. CORPORATION OF WISCONSIN.

CONTROLLER son ELECTRIC morons.

Specification of Letters Patent.

Patented Apr. 5, 1921.

Application filed November-21, 1918. Serial No. 263,594.

T 0 all whom it may concern v Be it known that I, HERMON L. VAN VALKENBURG a citizen of the United States, residing at Milwaukee, in the county of Milwaukee and State of Wisconsin, have invented a certain new and useful Improvement in ontrollers for Electric Motors, of Which the following is a specification.

This invention relates to automatic controllers for starting-and regulating the speed of motors. In controlling motors for operating printing presses, machine tools and similar apparatus it is frequently necessary to regulate the speed of the motor by means of resistance in series with the armature; and it is desirable in such cases to be able to preordain the speed. at which the motor shall finally operate, and then in starting the motor supply it, initially, through protective or starting resistance and automatically and gradually bring the motor up to the preordained speed by cutting out the starting resistance. It is also desirable to always subject the motor to the same inrush of current regardless of the speed at which the motor is finally to operate. The general object of my invention is to provide simple and eificient apparatus for accomplishing these desirabilities. Heretofore, it has been usual to provide two sets of resistances-a starting resistance, which is used to protect the motor against excessive initial current, and a regulating resistance, a portion of which remains in circuit, the amount depending upon the ultimate speed at which it is desired to have the motor run. a result of my invention it is possible to utilize a single set of resistances for both starting the motor and-regulating its speed. My apparatus possesses great flexibility or range of regulation; for example, in the form illustrated'it is possible to operate the motor at eight diflerent speeds by employing but three sections of resistance-these sections, as above stated, also performingthe function of starting resistance.

I accomplish my objects by the apparatus illustrated in the accompanying diagram. 1

Referring to the diagram, the current is supplied through the lines L L The motor has an armature A and a shunt field F. The line L is connected to one of the motor terminals, the other terminal being connect ed by a conductor 10 to three sections of reductor 25.

sistances R R R In the most developed form of my invention these resistances are graded, and in the preferred form they are contactor is controlled by a coil 14 connected at one end to the conductor L and at the other end by a conductor 15 to a hand switch 16 which is connected by a conductor 17 to the line conductor L By closing this hand switch the main line contactor 12 will be closed, thus closing the auxiliary switch 20 which is adapted to bridge the contacts 21 and 22 for energizing the coil 23 of the accelerating device, hereinafter referred to. Contact 21 is connected to contactor 12 through a conductor 24 while contact 22 is connected to the said coil through the con- The other end of coil 23 is connected to the line L through a conductor 26.

The accelerating device mentioned is here shown in the form .of a time limit relay having a plunger for operating a contactor 31 located in position to successively engage and thereafter maintain engagement with the contact fingers 32, 33, 34 in the order mentioned. The plunger has a stem 3.5 to which is attached a piston 36 working in a dash pot 37, and so constructed as to ermit the piston, plunger and contactor'to escend rapidly but rise slowly. -The contactor is lzept in circuit by means of a finger 38 sliding upon a stationary conductor bar 39 ermanently connected to the conductor 25. he fingers 32, 33, 34 are connected by conductors 40, 41, 42 respectively to coils 43, 44, 45 respectively for controlling the contactors 46, 47, 48 respectively. These oontactors are normally open and govern the resistances R, R and R respectively. The coils 43, 44, 45 are connected by conductors 50, 51, 52 respectively to contact points or fingers 53, 54, 55, respectively. A fourth contact point or' finger 56 is connected by a conductor 57 to the line conductor L The fin ers 53 to 56 form part of a regulator C w ich is here shown in the form of a drum controller, the drum whereof is capable of occupying eight difierent positions indicated by the dot and dash lines 1, 2, 3, 4, 5, 6, 7, 8. The drum has contacts arranged in four lines to engage the fingers 53 to 56, respectively. The contact 60 which is in line with finger 56 is adapted to engage therewith in all positions, except number 1 which is the position indicated in the diagram. This may be regarded as oil position and when the controller is in this position all of the resistances will remain in circuit during the entire time the motor is running, regardless ofthe position of the contactor 31 of the accelerating device. In line with finger 55 are four contacts, 61, 62, 63 and 64., These are all electrically connected, permanently, to contact 60 and are located at positions 2, 4, 6 and 8. In line with finger 54 are contacts 65, 66 which are electrically connected, permanently, to contact 60, and are located at positions 3, 4, 7 and 8. In line with finger 53 is contact 67 which is electrically connected, permanently, to contact 60 and is located at positions 5, 6, 7 and 8.

Operation: Let it be assumed that theparts are in the prestarting position shown in the diagram, with all switches open and the regulator C in off position. When the attendant desires to start the motor he closes the hand switch 16 thereby energizing the coil 14 and closing the main line contactor 12. This closes the circuit through all of the resistance in series thus: from the main line L through armature A, conductor 10 resistances R R R conductor 11, contactor 12, contact 13 to main line conductor L The motor thus starts with all the resistance in circuit. The closing of the main contactor 12 closes the auxiliary contactor 20 thus energizing the coil 23 of the retarding.

device and causing the contactor 31 to slowly rise and engage the fingers 32, 33, 34 one after the other. Engaging the finger 32 would energize the coil 43 through the conductor 40 if it were not for the fact that the conductor 50 leading from the'other end of the coil is on open circuit because the regulator drum is in off position andhence the contact 53 is not engaged. For a similar reason the engaging of the fingers 33 and 34 fails to energize the coils 44 and 45 as the contacts 54 and 55 are unengaged. So the movement of the contactor of the accelerating device or time limit relay has no effect to cut resistance out of -the motor circuit when the regulator is in ofl position.

Butassume that the regulator drum is in second position corresponding to dot and dash line 2, in the diagram. In such case, the drum' through its contacts 60 and61 will connect the contacts 55, 56 and hence when the contactor 31 of the time limit relay reaches contact finger 34, the coil 45 will be I hence when the contactor 31 of the time limit relay reaches the finger 33 the coil 44 will be energized and close the contactor 47, thus eliminating the resistance R The motor will then be supplied as follows: from the line L through the armature A, conductor 10, resistance R conductor 70, contactor 47, conductor 71, resistance R conin third position ductor 11, main line contactor 12, contact -13, to line conductor L Thus finally the current will be supplied through all of the resistances, in series, except resistance R As resistance R is here shown as being greater than resistance R it will be observed that the voltage finally supplied the motor is somewhat higher than when the drum of the regulator is in second position, previously described.

y positioning the regulator drum in fourth position, corresponding to dot and dash line 4, the contacts 54 and 55 will both be connected to contact 60, and the resistances R and R will both finally be cut out by the energization of the coils 44 and 45 as explained. If resistance R is twice as greatas resistance R this will cause the final elimination of three unit values of resistance from the motor circuit.

If the regulator drum occupies fifth position corresponding to clot and dash line 5, the resistance R alone will be finally eliminated, the current flowing from the line L through armature A. conductor 10, resistances R and R conductor 72, contactor 46, conductor 11, contactor 12, contact 13, to line conductor L By following out the remaining positions it will be evident that eight ultimate values of resistance in the motor circuit may be obtairiied as may be expressed by the following tab e.

Regujqtor in Resistance finally in posmon-- circuz'l. No. 1 All :7 units. No.2 R plus B :6 units. No. 3 R plus R :5 units. No.4 R :4 units. No.5 R plus B :3 units. No. 6 "R units. No.7 R :1 'unit. No. 8 .1) :full line current.

The apparatus may be employed as a hand starter if desired: To illustrate, supthe sections ofresistance.

by reinsert the resistance R but eliminatethe resistance R thus reducing by one more unit the amount of resistance finally in circuit. By thus proceeding he can 'cut out the resistance unit by unit until he has moved the regulator drum to eighth position, whereuponall the resistance will be cut out of the motor circuit.

From the foregoing it will be seen that the apparatus possesses great flexibility and range of operation. By setting the regulator drum at any given position the motor may be started and stopped as often as may be desired, and when restarted will always return to the same speed. This ultimate speed may be Varied either while the motor is running or before starting; and as above pointed out. if desired, the device may be used as a hand operated controller.- It will be noted that in the form described and shown the values of the resistance are graded in geometric progression. It will also be noted that the circuits of each of the controlling coils 43, 44, 45 have what may be regarded as two switches in series with each other, one switch being a part of the accelerating device or time limit relay, and the other a part of'theregulator or drum controller, and a final effect upon any one of the coils will depend upon both of these factors. It will also be noted that, regardless of the position of the regulator drum the initial inrush of current will be the same, for at the beginning the motor will be supplied with current which traverses, all of A further char acteristic of the apparatus is that the sameresistance is used both as starting and regulating resistances. This is an advantageous distinction to certain known types of apparatus in which two sets of resistances are employed, one for starting the motor and the other for regulating its speed.

It is evident that the contactor 31 of the time limit or accelerating device may properlv be termed a starting switch.

aving' thus described my invention what I claim as new and desire to secure by Letters Patent, is':

1. A motor controller having a plurality of sections of resistance in series in the motor circuit, a regulator adapted at will to vary the sequence in which said sections shallbe cut out of circuit, and a time 0011- trolled starting switch adapted as it advances to cut out the sections in the sequence previously determined by the regulater.

2. A motor controller having a set of resistances of diii'erent values in series with the motor, each of said resistances having a control circuit, a regulator switch adapted to beset in different positions to partially control different combinations of said circuits ingrou s of two at a time, and a starting switc adapted, as it advances to complete the control solely of the circuits preselected by the regulator switch.

3. A motor controller having a set of at least two resistances of difierent values in series in the motor circuit, a control circuit for each of said resistances, a regulator switch adapted to be preset and having at least three positions in one of which both sections of resistance will remain in circuit and in another of which the smaller of said resistances will remain in circuit and the larger will be cut out, and in the third position the larger of said resistances will remain in circuit and the smaller will be out out; and a starting switch adapted to travel along a definite path and'in doing so to cut out the resistance or resistances preselected for the purpose by the regulator switch.

4. A motor controller having a set of at least three resistances of diiferent values in series with the motor, each of said resistances having a separate control circuit, a

regulator switch adapted to be set in more than three different positions to preliminarily and partially control diiierent combinations of said circuits, and starting switch mechanism having a movable contactor and adapted as the contactor advances to complete the control of those circuits preordained by the regulator switch.

5. A motor controller having a set of at least three resistances of different values in series with the motor, each of said resistances having a separate control circuit, a regulator switch adapted to be set in six diiferent positions to preliminarily and partially control'any one of said circuits and any two of said circuits in groups of two, and all three of said circuits as a group, and starting switch mechanism having a movable contactor and adapted, as the contactor advances, to complete the control of those circuits reselected by the regulator switch.

6. motor controller having a plurality of sections ofresistance in series in the motor circuit, an electromagnetic switch for governing each of said sections, a control circuit for 'each of said switches, a hand regulated switch, and an accelerating switch, the last mentioned two switches being arranged in series in each of said control cir- ,cuits.

7. A motor controller having a plurality ofsections of resistance permanently connected all in series in the motor circuit, an electromagnetic switch for governing each of said sections, a control circuit for each of said switches, a hand regulated switch, and an accelerating switch, the last mentioned two switches being arranged in series in each of said control circuits. 1

8. A motor controller having a set of resistances of difierent values in series with the motor, each of said resistances having a control circuit, a hand adjustable regulator adapted to combine said circuits in groups of any one at a time and any two at a time, and a time controlled switch adapted to control, one after the other, the individual circuits reviously grouped by the reguiator.

9. 12 motor controller having a set of at least three resistances of different values in series .with the motor, each of said resistances having a control circuit and said control circuits having their terminals distributed, a hand adjustable regulator adapted to combine said circuits in a group of three and ingroiips of any one at a time and any two at a time, and a time controlled switch adapted to engage said terminals successively to control, one after the other, the individual circuits previously grouped by the regulator.

10. A motor controller having a set of at least three resistances of different values in series with the motor, each of said resistances having a control circuit and said control circuits having their terminals distributed, a hand adjustable regulator adapted to be preadjustedto different positions to combine said circuits in a group of three and in groups'of any one at a time and any two at a time, a starting switch adapted to engage said terminals successively as it advances, to control, one after the other, the individual circuits 1previously grouped by the regulator, an e cctromagnetic winding for urging said starting switch to advance, and means for retarding the advance of the startin switch.

11'. motor'controller having graded resistances, electromagnetic switches for governing said resistances, control circuits individual to saidswitches, a hand controller neraeec having a greater number of positions than the number of resistances, and a time limit relay cooperating with said controller for determining which of said resistances shall ultimately remain in the motor circuit, each position of the controller, except the ofi position placing a difi'erent combination of said resistances on closed circuit.

12. A. controller for electric motors having a plurality of resistances, magnetic contactors for governing said resistances, said contactors having electromagnetic coils for controlling them, a speed regulator adapted regulator terminal and the other an accelerating terminal, a regulator adapted to occupy different positions to connect difl'erent regulator terminals to one side of the supply line, and an accelerating device for connecting the accelerating terminals successively to the other side of the supply line.

14. A motor controller having at least three sections of motor circuit, said resistances being of difresistance in series in the ferent values, a manually operated regulator adapted to be set in difierent positions to partially control said resistances, and adapted to preordain both the sequence in which said resistances shall be cut out of circuit and the total numberwhich shall be cut out of circuit, and the controller, if one section is to be cut out of circuit, being adapted to control difierent groups of two to preordain what groups of two shall be cut out of circuit, and a starting switch adapted as it advances to cut out the sections preordained by the regulator.

In witness whereof, I haveihereunto subscribed my name.

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