US940164A - Motor-controlling device. - Google Patents

Description

C. D. KNIGHT. MOTOR GONTROLLING DEVICE.

APPLICATION I'ILED JAN. 21, 1907.

VPatented Nov. 16, 1909.

MAO.

Inventor I Witnesses lght.,

" TED STATES' rATENT OFFICE.

' 1 2 D. KNIGHT, OF SGHENECTADY, NEW YORK, ASSIGNOR TO GENERAL ELEGTBIC COMPANY, A. CORPORATION 0F NEW YORK.

mironeeonfrnomme nnvren.

Y Speciicaton of Letters Patent.

' Patented Nov. 1e, 1909.

Application Med January 21, 1907. Serial No. 353,196.

To all whomrit may concemr.

Be it known that LCHARLES D. KNIGHT, a citizen of the Unitedl States, residing at Schenectady, county of Schenectady,` State of New York, have invented certa-in 'new and useful Improvements in Motor-Controh meanswhereby the motor may be stopped and started, and the speed varied in a reli.

able, safe and efficient manner.

. In the operation of certain types of machines, it is highly desirable that the speedy of the machine be beyond the control of the c operator. It is also desirable that thespeed itself be variable. This is particularlytrue of printing presses in which the Work will sometimes permit-of one speed and sometimes another, while the speed must be maintained constant during the' performance of a specified pieceof work.

In carrying o ut my invention, I provide means of connection with a starting rheostat whereby the speed will automatically be brought to a predetermined point as soon as the controlling element of the starting rheostat reaches a certain definite position, which will usually be the inning position. I also provide means 'whereb the speed, which the motor will automatica ly assume may be varied and the arrangements are such that when the motor isv startedit will automatically come up to the eed at which it was running before it was ast shut down. The

.most desirable method ofvarying the speed of the motor is by varying the field strength and it is necessary when the motor is started that the field be of maximum strength. I therefore provide means whereby when the line switch is closed, the field will be automatically brought toits maximum strength,

and as soon as runningconditions are established, the iield strength will automatically be varied so as to give the desired speed.

In the accompanyin drawing I have shown my invention em odied in a typeof circuit controlling device best adapted for printing press control. A l

AThe particular printing press controller hereinshown and described forms the subject matter of a patent issued to William C.

Yates/4, So. 857,142. A detailed description of this particular controller thenis unnecessary since it forms no part of my invention. In general, however, it consists of a starting resistance 1 provided with a seriesof contact studs 2 and reversin studsl 3, the latter be- 16o ing less in number t an the former'and being' connected with `the first three of the starting studs. The controlling arm 4 1s pivoted at 5 and 'biased to the lcentral position shown in the drawing by a double-acting spring 6 while a retaining magnet .7V-ils arranged to hold the arm 4 in running position in vthe usual manner. When the controlling arm 4 is moved to the right, the motor' will be started cuttingout the resistance' 1 in the usual Way until the magnet 7 is reached. where the resistance istshortcircuited. During the starting operatlon the direction of current will be as follows: from the line at L through the conductor 8, arm ,4, conductingsegment v9 thence by conductor 10 through .armature A, conductor 11, conducting segment 12 toiresistance 1 thence back to line L through conductor 13' and series field F. Upon fallure of voltage the arm will return to the off position in the usual way.A

Inorder that the printing press or other machinewith which this device isused may be jogged along at a low speed, a systeml when the controlling arm is in the oit posi tion. vThis is accomplished by meanso a.

series ofl push vbuttons B B B controlling a control circuit represented by the mains 'C 'C. A solenoid' S is arranged `in this control circuit so that if any one of the buttons or switches B is operated, the solenoid wlll be energized. The core 4of the solenoid 1s provided with two contacts D D', each cop- 95;

erating with a pair of contacts to control a separate circuit. Contact D controls the circuit of the retaining magnet 7 so that when the push button is operated, the'magnet 7 will bedenergized and allow-the con- 100 trolling arm to return to the olf position. The contact D controls the armature circuit during the. process of Vjogging, so that i when the button is pressed contact D willclose the circuit and the direction of current '1o5 tact D, conductorl 16 through a portion of 119 of control is provided which lis operative the resistance 1 and conductor 13 to line at L through the series field F. It will be noted that the motor, when controlled by the buttons B, has permanently in circuit a portion of the resistance so that the motor will be jogged along at a' low speed. By actuating the button B again so as to deenergize thesolenoid S, thecircuit will be open so that the motor may be quickly stopped and started at a slow speed from various points around the machine where the buttons B may be located. The buttons will also stop the machine at any time when ruiming at normal speed 'by -denergizing magnet 7.

Vr l he above described device is all shown and'described in the application above referred to. ,ln said case, however, the speed at which the machinecould be operated is controlled by'hand, and -no provision made against starting with a weakened field nor was'there anymeans for keeping the speed regulation out of the operators hands. To accomplish this result, l provideva speed regulating resistance 17 which I have shown.

in series with the shunt field F', the motor in this case being of the compound wound type although other types of motors-may be used without departing from the spirit of my invention. The iield resistance 17 is varied by a controlling member 18 pivoted at 19 so that if unrestrained it will always retilrn by gravity ory otherwise to the position shown in the drawing. In other words it has a bias away from the full field position. This arm is actuated by an electromagnct device having two 'windings 20, 21 and a dash-pot 22 is arranged to retard the arm it moves downward 1n response to its bias. An adjusting screw 23 is arranged to engage the a/im 18 so as to limit its movement as desired. This adjusting screw may, if desired, be beyond the control of the operator and only accessible to some person in authority. The coils and 2l are energized from the .line L through conductor 8, conductor 24, switch 25, conductor 26 thence through the two coils 20 and 2l in parallel and back to line through conductor 29. The coils being energized the arm 18 is raised until the field resistance 17 is all cut out. hen this oint is reached the switch 26 in the circuit ot' the solenoid 2l is opened by an insulated finger 27 on the controlling arm so that only one coil is acting on the core, but ,this is suilicient to hold it in a raised position. The motor is now started with the full iield, either by means of the switches B orby moving the arm 4 toward running position. Vhen operating by means of the switches, the field strength is not varied but when the controlling arm is moved over so as to give the motor full ced, it opens the circuit or" the magnet 20 at the switch when running conditions neonazi are established, z'. e., when the arm 4 reaches the retaining magnet 7, an insulated iin er 28 opens the switch 25. Both solenoids eing denergized, the arm 18 will drop against the retarding inuence of the dashpot until it 'engages the screw stop 23. This movementl of the arm will, of course, weaken the field of the motor, and in the present case, speed up the machine. It will thus be seen that I have provided means for automatically varying the speed of the motor so as to place it beyond the control of thel operator, and at the same time the field of the motor will have full strength at starting. l

While I have described my invention in connection with a particular type of motor, namely, one adapted for printing press control, and described in the previous application, it should be understood that it is in no sense limited to this particular application, it being shown in this connection principally for purposes of illustration. lt should also be understood that many changes will suggest themselves to those skilled in the art, all of which will come Within the spirit oi my invention in so far as they fall within the scope of the claims annexed hereto.

What l claim as new and desire to secure by Letters Patent of the United States, is

l. The combination with an electric motor and a starting rheostat therefor, of means independent of said rheostat for causing the speed of said motor to be automatically and gradually varied a predetermined amount when the controlling element of the rheostat reaches a certain position and means for changing the amount of said variation.

2. The combination with an electric motor and a starting rheostat therefor, of means independent of said rheostat for automatically. and gradually increasing the speed of said motor a predetermined amount when the controlling 'element of thc rheostat reaches running position and means for varying the amount of said increase,

3. The combination with an electric motor and a starting mechanism therefor, of means for automatically and gradually varying the field strength of said motor when the starting mechanism occupies a certain fixed position and means for changing the amount of said variation.

4. The combination with an electric motor and a starting mechanism therefor, of a field resistance, means independent of said starting mechanism'for automatically and gradually increasing saidv resistance when the starting mechamsm reaches running position and means for varying the amount of said increase.

5. The combination with an electric motor and a starting rheostat therefor, of a field resistance, a controlling member therefor having a bias away from full field position,

trolling element therefor, a speed regulating.

resistance, means independent of seid con# trolling element for automatically and gradn uallyy varying said latter resistance a predetermined amount when the starting element is moved to running position and means for changing the amount of 'said variation.

7. A. controlling device for electric motors comprising starting mechanism, a field resistance having a controlling member biased to a predetermined position, and means controlled by the starting mechanism for automatically causing said controlling member to move to a -second predetermined position and return in response to its bias.

8. A controlling device for electric vmotors comprising starting mechanism, a field resistance having a controlling member biased away from thefull field position, and means" controlled by the-starting mechanism for causing said controlling member to automatically move to the full eld position and return in response to its bias.

9. A controlling device for electric motors comprising starting mechanism, a eld resistance having a controlling member biased away from the full eld position, means for causing said controlling member to automatically move to the full field position, and means controlled by the starting'mechanism for causing said member to return in response to its bias.

l0. A controlling device for electric motors comprising a starting resistance, a controlling element therefor, a field resistance having a controlling member biased avvay from the fnll field position, an electromagnetic device for moving said member toward the full field position, and means for deenergizing said device When the controlling element of the starting resistance reaches running position. p

1l. A controlling device for electric motors comprising a starting resistance, a controlling element therefor, a field resistance having a cont-rolling mcmber'biased away from the full eld position, an electromagnetic device energized when the line circuit is closed for moving said member to full field position and denergized allowing it to return in response to its bias- When the con-l trolling element' of the starting resistance reaches ruiming position.

' l2. A controlling device for electric motors comprising a starting resistance, a controlling element therefor, a field resistance having a controlling member biased away from the full field position, an electromagnetic device for moving said member toi/yard thefull field position, means for partially denergizing said device when tne. member -reaches said position, andlmeans for totally denergizing the device thereby permitmg the member to respond to its bias when the .controlling element of the starting resistance reaches running position.

i3. A controlling device for electric mo-l tors comprising a starting mechanism, a speed regulating resistance having a controlf ling member biased to a predetermined position, means controlled by the starting mechanism forautomatically causing said controlling member to move from said predetermined position and return in response to its bias, and' means for varying said predetermined position.

' le. A controlling device for electric mo tors comprisin a start-ing mdchanism, a field resistance iaving a controlling member biased to a predetermined position away from full ield', means controlled by the starting mechanism for causing said controlling member to automatically move to the full field position, and means for varying said predetermined position.

l5. A controlling device forl electric motors comprisinvf a starting mechanism, a field resistance aving a controlling member biased to a redetermined position away from full held, means controlled by the starting mechanism for causiiiA saidcontrolling member to automatically move to the full field position and return in response to its bias, and means for varying said predetermined position.

16. The combination with an electric motor and a starting rlieostat therefor, of means whereby the motor maybe controlled through a portion of the starting-resistance with the controlling element in starting po' determined amount When ,the .controlling member of the rheostat is moved from said position.

i7. The combination with an electricv motor and a starting rlieostat therefor, of means whereby the motor may be controlled through a portion of the starting resistance when the controlling arm of the rlieostat is in the odposition, and means for causing the speed of said motor to be automatically varied a predetermined amount when the controlling 'member of the rheostat reaches running position.

i8. The combination with an electric niotor anda starting rheostat therefor, of a plurality of switches. means whereby the motor may be controlled through a portion of the starting resistance from said switches, and means for causing the speed of the motor to be automatically varied a predeterche moioz? iin-137 'ba controed from said omes hrouz; a gpozion of the starting resistance with 5o.@ rheostatc contfolng eemen in poson, u ed resst mom a oonrong membr therefor biased avi-ay :from the :5113i field posizion, 'means for causing Said contr-Ming sns-mbar to automaczly move io th@ fu ield position, and means for musing d member to automatically mmm ,in )i nso io its bias when the conl'oling Moment of the sartng rheosw roaches running position.

Xn wi ess Who'eo", have hereunto set my hund this 19th day of January, i937.

KNIGHT.

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