US1878334A - Motor controller - Google Patents

Description

Sept. 20, 1932. E w SEEGER 1,878,334

MOTOR CONTROLLER Filed Aug. 4. 1930 16 Run 1? STOP REV.

mg press control Patented Sept. 20, 1932 UNITED STATES PATENT. OFFICE EDWIN W. SEEGEB, OI WAUWATOSA, WISCONSIN, ABSIGNOB TO INC 01 MILWAUKEE, WISCONSIN, A CORPORATION 01' DELAWARE KOTOB CONTROLLER Application filled August 4, 1080. lerlal Io. 473,000.

This invention relates to electric motors. It is particularly controllers for advantageous for printw ere it is desired to operate the press at various predetermined speeds and where the motor is to be controlled from a control station located conveniently to the press, while the control apparatus proper, which commutates the heavy motor current, is located near the motor, thereby conserving wiring. a

An object of the invention is to provide a controller in which the motor may be started,

stopped and reversed from suitable push butr ton stations located at a distance from the motor.

Another object is to rovide a controller in which the speed at w ich the motor operates may be set at a control station located conveniently to the push buttons.

Another object is to provide a controller of the aforementioned type affording a relatively large number of speeds with a minimum number of resistor steps and control switches therefor.

Another object is to provide a controller of the aforementioned type in which the torque of the motor may be temporarily increased to provide for starting or reverse rotation thereof.

Another object is to provide a controller, requiring a minimum of floor space near the ress. 1

p Other objects and advantages of the invention will hereinafter appear.

The accompanying drawing illustrates one embodiment of the invention.

A three phase slip ring type induction motor 1 having primary terminals 2, 3 and 4 and secondary terminals 5, 6 and 7, is shown as constituting the driving motor. The motor is supplied with power from the three phase power mains L, L and L throu h a pair ofelectromagnetic reversing switc es 8 and 9 for forward and reverse operation, respectively. The switchB is equipped with normally .open main contacts 8a, 8b and 8c, normally closed auxiliary contact. 8d and an electromagnetic winding 8e, while the reversing switch 9 has normally open main contacts 9a, 9b and 90, a normally closed auxiliary contact 9d and an electromagnetic winding 96. The secondary terminals 5, 6 and 7 of the motor are connected to three sets of star connected resistors, the base connected to the terminal 5 embraces t e resistors R, R and R, the phase connected to terminal 6 embraces the resistors R R and R while the phase connected to t e terminal 7 cmbraces the resistors R", R and R". Cornespondi'ng resistors in the three phases are preferab of equal ohmic value, while the ratio of t of the resistors in each ometric regression, that is the resistor R as twice the ohmic value of the resistor R and theresistor R has twice the ohmic value of the resistor R. It is thus possible by properly combining the different steps of resistors to obtain a number of speed points for the motor which exceeds the number of steps of resistors in each phase. Thus in the present case with three steps of resistors per phase it is ossible to spe oints, inc uding the speed at which all of t e resistance is short-circuited.

The resistors are controlled b electromagnetic switches 10, 11 and 12. 'l he switch 10 has normally 0 n main contacts 10a, 10b and 100 and an e ectroma etic winding 10d. The switch 11 has norma 1y 0 en main contacts 11a, 11b and 110, a norm ly closed auxiliary contact 11d, a normally open auxillary contact 11c and an electromagnetic winding 11;. The switch 12 is equipped with normally open main contacts 12a, 12b and 120,

electromagnetic winding 12 A presettable manually operated speed controller 13 provides for control of the elece ohmic value of successive stepsphase is preferably a et a total number. of ei ht v tromagnetic windings of switches 10, 11 and 12. The controller 13 is equipped with a pivoted contact lever 13a which is designed to engage contact buttons 13b to 132', inclusive, and the concentric contact segment 1310, which latter-extends over an are including the contact buttons 13g to 131', inclusive. The outer end of the lever 13a is so arranged that it maqy bridge two contact buttonssimultane The apparatus also includes an electromagnetic switch 14 having stationary contacts 14a'and 14b;a bridging contact disc 140 which normally disengages said stationary contacts, and an electromagnetic operatin winding 14d. Also there is included an e ectromagnetic relay 15 having a winding 15a and normally open contacts 156 and 150, and on the press at a point convenient to the operator are mounte a series of ush button switches as follows: a normally c osed switch 16, a reversing switch 17 havin normally closed 15 contacts 17a and a norma y open triple contact 17b, a running switch 18 having normally closed contacts 18aand normally open contacts 18b and an inch switch 19 aving normally open contacts 19a. The running button is uipped with a pin 18d, which registers wit .a slot in the cover, so that the button ma be partly depressed and upon turningxloc ed in that position.

practice the ush buttons and the speed regulating contro ler 13 may be mounts together at a convenient point on the ress.

The apparatus functions in the ollowin manner: f it is desired to start the press an operate it at a certain speed corresponding II, to that position of the contact lever 13a in which it makes contact with the button 13g, the control lever 13a is moved to the corres onding s ed position. In order to start t e press t e (perator pushes the running I button, thus bri ging the normally open contacts 186 by the contact disk 180. A current then-flows from the line L through the sto button and the reverse button over the le hand stationary contact 18b, contact disk 180, ll winding 15a, to line L. Relay'l!) is thus ener 'zed and closes its normally open contacts 15 and 150. Thus a circuit is completed from line L through the stop and reverse buttons contacts 15b through winding 15a and Al line The relay 15 thusremains energize after the running button is released. A second circuit is closed from the reversing button through contact 150, contact 9d and windin 86 to line L. This energizes switch 8 an said switch com letes the circuit to the primary winding of t e motor, one circuit extending from L over contact 80, to term nal 2 of the motor, the second extending from line L over contact 8a to terminal 4 of the motor, while the third circuit extends from line L P over Contact 86 to termmal 3 of the motor -ton 13h, thus interrupting the circuit through Current thereupon also circulates through the secondary winding and resistance of the motor and the latter tends to start. The usual printing press, however, requires -a starting torque of considerable magnitude, and this torque could not be exerted .by the motor with all of the speed regulating resistance in circuit. To increase the torque of the motor'sufliciently to start the press there press at a slow amaze is provided the torque switch 14 which functions asfollows: As long as the button 18 is depressed a circuit is completed from line L through the stop and reversin button, stationary contacts 18b, through windin 14d to line L. Thus switch 14 is energize thereby closing its normally open contacts which are connected to three points of the star connected resistor, so that when the switch 14 is closed part of the speed regulating resistance is short-circuited, and the remaining resistance is sufiiciently low to permit the motor to start. With the switch 14 closed the current in one phase of the secondary winding of the -motor passes from terminal 5 through art of the resistance R to the contact 14b. urrent in a second phase passes from terminal 6 through part of resistance R" to contact 140,

while current from the terminal 7 passes through part of the resistance B- through contact disk 140 so that when closed the contacts of switch 14 form the star or neutral oint of the resistance remaining in circuit. e runnin button 18 is held in the depressed position by the operator until the ress has started, whereupon he releases it. n the released position of the running button the switch 14 is again deenergized and all of the speed regulating resistance is reinserted in the secondary circuit of the motor. When the push button 18 returns to its normal position a circuit is. completed from line L- through the stop and reversing button, contact b, contact disk 18c and normally closed contact 18a to lever 13a, through contact button 13g, through normally closed contact 11d, through winding 10d of switch 10 to line L. Another circuit is completed from contact 130, through segment 13k and winding 12 to line L. Thus the switches 10 and 12 are energized, the switch 10 short-circuiting the resistance R, R and R while the switch 12 short-circuits the resistances R R, and R". The motor is thus accelerated until d its speed corresponds to the value of the resistance in circuit, which is now R, R" and R, res tively.

If it is desired, after starting, to run the slpeed inde endent of the setting of the re ator 13, t e button 18, after it has been fu y depressed and the press has started, is locked in its intermediate position, whereu n the motor continues to revolve with al speed re lating resistance in circuit. If it is desire to increase the speed of the ress, the lever 13a is moved to the next butthe coil 10d causing insertion of the resistances R R and R", while the coil 11f is energize through-the normally open contact 12a of switch 12, the latter contact being closed as switch 12 is energized. In the new position only the resistances R, R and E remain in the motor circuit. It will be seen that upon movement of the lever 13a in the reverse direction a greater amount of resist- I off position.

time is inserted in the secondary circuit of the motor, thus decreasin its s The various switches 10, 11 an 12 are so interlocked that they will have to close and open in the desired order.

If it is desired tosto button is depressed. T through the coil a, thus eenergizing the switch 15, thereby openingthe circuit and disconnecting the motor from the line. At the same time the circuit leading to controller 13 is opened so that any of the switches 10, 11 and 12 which may be in the closed position are also deener 'zed, thereby reinserting all resistance in t e motor circuit.

If the motor is standing still and it is desired to merely move the press a short distance by temporarily energizing the motor, the inch button 19 is depressed. This closes the circuit from line L through the stop and reverse buttons, through the inch button, through the winding of the switch 14 to line L. The switch 14 is thus energized and short-circuits part of the regulating resistance in the manner aforedescribed. At the same time a circuit is also completed through the contact disk of button 19 through contact 9d, winding 8e to line L. This energizes the switch 8 and connects the motor to the line, causing it to start. The motor will revolve only as long as the switch 19 is depressed. Release of said switch will cause the apparatus to immediately return to the off position, thereby stopping the motor.

It is sometimes desired to reverse the direction of rotation of the motor. This is accomplished by means of the reverse button 17. If this button is depressed the circuit through the normally closed contacts of the motor the sto switch 15 as well as the circuit to the run and inch buttons are opened, and a circuit is completed from line L throu h the stop button,

over contact 176, throng 9e to line L.

contact 8d, coil This energizes the reversing primary switch and connects the motor terminals to lines L, L and L, but with the terminals 3 and 4 reversed relative to the lines L and L. A circuit is also com leted from the center contact 17 b, throug coil 14d to line L, thus energizing the switch 14 and short-circuiting part of the regulating resistance in the manner aforedescribed to enable the motor to start up. Reverse connection of the motor is maintained only as long as the reversing button is depressed. As soon as it'is released the switches 14 and 9 are deenergized and the controller returns to the It is obvious, that the reverse or inch push button or both may be omitted without departin from the spirit of my invention.

Whi e I have shown only one push button of each type, in practice a multiplicity of buttons may be used in a manner well known and practiced in the art.

geometric progression with a ratio is 0 ns the circuit.

What I claim as new and desire to secure by Letters Patent is:

1. In a controller for alternatin current motor, in combination, speed regu ating resistances having ohmic values which vary in of two, electromagnetic switches for excluding said resistances in different groupin to provide for operation of the motor at 'fferent running speeds, a presettable control switch for said electromagnetic switches to afford selection of the running speed of the motor, and

starting means for the motor includinig a ed to e ect push button switch to be depress starting andslow speed operation of the motor regardless of the setting of said presettable switch and to bereturned to a given position to effect acceleration of the motor to the s eed selected by said resettable switch. 2. In a controller for a ternatin current motors, in combination, speed regufating resistances having ohmic values which vary in geometric progression with a ratio of two, electromagnetic switches for excluding said resistances in different groupings to provide for operation of the motor at different running speeds, a presettable control switch for said electromagnetic switches to afford selection of the running speed of the motor, and starting means for the motor including a push button switch operable to effect starting and in one position slow speed operation of the motor re ardless of the setting of said presettable switch and in another position operation at the preselected higher speed, said starting means further including means to effect in starting of'the motor as aforedescribed exclusion of a given amount of said resistance to afford the motor a high starting torque.

'3. In a controller for alternating current motors, in combination, speed regulating resistances having ohmic values which vary in geometric progression with a ratio of two, electromagnetic switches for excluding said resistances in different groupings to provide for operation of the motor at different running s eds, a presettable control switch for said e ectromagnetic switches to afford selection of the running speed of the motor, and starting means for the motor including an electromagnetic switch to exclude a given amount of said resistance for high torque in starting and further including a push button switch which in one position effects starting of the motor with said given amount of resistance excluded from circuit, and which has other positions wherein it is adapted to effect operation of the motor at slow speed, and operation of the motor at a higher speed which is determined by the setting of said presettable switch. 7

4. In a controller for alternating current motors, in combination, speed regulating resistances having ohmic values which vary in geometric progression with a ratio of two electromagnetic switches for excluding said resistances in different groupin to provide for operation of the motor at ifl'erent running speeds, a presettable control switch for said electromagnetic switches to afford selection of the running 5 eed of the motor, and starting means for t e motor including an electromagnetic switch to exclude a given amount of said resistance for high torque starting and reverse operation and further including a push button switch which in one position effects starting of the motor with said given amount of resistance excluded from circuit, and which has other positions wherein it is adapted to effect operation of the motor at slow speed, and operation of the motor at a higher speed which is determined by the setting of said presettable switch, and reversing means including a second ush button switch which eilects reversal o the motor with said given amount of resistance excluded from circuit.

In a controller for alternating current motors, in combination, speed regulating resistances having ohmic values which vary in geometric progression with a ratio of two, electromagnetic switches for excluding said resistances in different groupings to provide for operation of the motor at different running speeds, a presettable control switch for said electromagnetic switches to afford selection of the running speed of the motor, and starting and reversing means for the motor including push button switches operable to efiect starting, slow speed and reverse operation of the motor regardless of the setting of said prescttable switch, one of said push button switches being further op erable to efi'ect starting of the motor for op eration at the preselected higher speed, said starting and reversing means further including means to efi'ect starting and reversing of the motor as aforedescribed exclusive 9. given amount of said resistance to afford motor a high starting and reversing to:

6. in a controller for alternating current motors, in combination, an electromagnetic reversing switch for connecting the motor 5 to the supply circuit for forward and rotation, speed reguiating resistances "or -ts armature circuit having ohmic values vary in progression with. r" two, electromagneti switches for said resis' ces in d1 rerent groupii vidc for o the motor at esettabie cor ntioned eiec'tr :n selection or i cash button I r JQISiBg on cfitec'ts motor with rotation not of resistance "minded tram ti sore circuit and which has other posit be motor,

reverse I given amount of resistance excluded from the armature circuit.

In witness whereof I have hereunto subscribed my name.

EDWIN W. SEEGER.

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