US868381A - Motor-control system. - Google Patents

Description

PA' I'ENTED OCT. 15, 1907.

v Invention Hcn" EWhHCe.

AW y. l

' HARoIQo E. te

UNITED STATES PAlEKT OFFICE.

or. mommy, NEW XORK, ASSIGNOR TO GENERAL ELECTRIC GOMPANY-, A oonromrrox or NEW-roan. I

MOTOR-CONTROL SYSTEM.

. Specification 0t Letters Patent.

' l Patented Oct. 15, 1907.

Application filed Tehran-3 27,1906. Serial No- 303,218.

To all whom it may cancer-1a.: I Be it known that I, HAa'oLD nrwgn 'a' citizen of the United States, residing at Schenectadycou nty of Schenectady, State of,New York, have invented certain new and useful Improvements in Motor-Control Systems, of-which the following isa;specific ation. I

v The present invention relates to ineans ior'control-- ling electric motors and particularly motor's adapted to operate printing presses, or other machines which it may be desired to start "and stop fquickly from a plurality of points and to operate slowly under the control of the operator while near the machine and. at a'distance from the main controlleri- A L i The present invention has for its object an improved: control apparatus of the character specified and to this end, comprises the novel construction and arrangement of parts to be hereinafter described and particlilarly I pointed out in the claims.

In the accompanying drawing, Figure 1 indicates diagrammatically a" complete control system arranged in accordancewith the present invention; Fig'. 2 is a side elevation of the main controller having its inclosing casing removed; and Fig. 3v is a section-taken. on line 3, 3, of Fig. 2.

Referring to the drawings, A represents amotor having an armature a, a shunt field winding ahand a se-,

' ries field winding a 1 L and L indicate a source of current supply.

It is a resistance across variable portions of'which the motor armature is adapted to be-connected in starting.

1' is a variable resistance in the shunt is a -braking resistance. I

C is a controller adapted to andr. D is a relay governed by the, controller 0 and serv ing to make and interruptthe armature circuita'ndto short-circuit the motor armature through braking re sistanceR E is an overload relay, and F, F, -F, are normally closed push buttons in series with the contacts e of the overload relay and the actuating coil of the relay D.

. tact piece 3, are provided int-controlling tlie rclay D. I

The controller is illustrated as comprising two sets of fixed contacts 0 to cand s to 0 and two sets of movable contacts 1 to 6, and 7 to 12; together with a series of stationary contacts "o connected to the resistance r and a movable brush C electric-Lilly 6011- nected to the contact segments 6 and 12 1" or cooperating with the stationary contacts c. Additional contact fingers, 1 and 2', cooperating with filllOvfl ble con- When the controlleris inits fo ii position, as .illustrated, the contact segments 5 and 11 engage, respectively,-with contact fingers and c, sothat a circuit may be traced from.the'right-haii'd' te'nninitlof connect the motor to the V source of supply in proper relation to the resistance R nee ted" to the; as

rotation'o'i the controller so that the brush C SW0 the motor armature, through one section of resistance R, through contacts c, 11, 5, and 0 to the lefthand terminal of the motor armature, and another circuit through contacts (1 and d of the relay and resistance R Upon closing switch 8,. current flows from line L, through resistance 1, through theshunt field winding, back to line L. Thus, if the motor is in operation and the controlleris returned to the off position, the armature is short-circuited upon itself and produces a dynamic braking action. In moving 'to the first running position, engagement is made be tween contacts 1 and 2 and contact 3, as will hereinafter 'be described, and during this period ofcontact,- current fiows ifrom line L, through the actuating coil of relay D, through the contacts 1 of the overload rolay, through the push buttons F, through contacts s and 8, through controller contacts 2, 3 and 1, contacts 0, 6, 12 and c, to line L This energizes the relay D and the contact member d is lifted into ongagement: with the fixed contact J. At the same time auxiliary contacts d are closed and a maintain-- ing circuit is established through these auxiliary contacts of-the relay D independently of the contacts 1, 2 and 3 of the controller. Therefor the controller has fully reached its first run motion the contact 3 mayletve contacts land 2 without causing I the rela'yiD to. drop. Withthe relay energized, a circuit may be traced from line L through the contacts (1 and d of the relay, to point 4, which one branch passes through the resistance R, to series field coil a contacts 0 7, 1 and c blow-outl coil B, to

line L. A second branch fron point 4, passesthrough the motor, arrnatnre throughthe r y jibs ghq n..ire t .st Thu In second position of the con- 7 troller, the circuitsirgmain the same, except that the armature circuit", reaching .contact. c, flows through contacts 10 and 0 to point 7 on the resistof the overload; m po ts parallel withgaportion of anc; the'armature being now shunted across an in ,I

In the creased resistance. 7 I p 4 positions, including the .fifth same. way, in succeeding lllilg position, the,

connection with one :niotor ternunal and the resist=,..-

aucc passes successivelythrouglrpoints.8v 1 0, an l 11. Segment 1" reaches only tr ugh gt n o si, tion so that in the sixth positigu,,m d thenoafter,. ourrent flows directly from line I thro of the relay D, through the s t-u ilised s e? i f t e e; ewes t let-t e line L, the resistance being entirely semin rs H 7 motor and furthor increase in speedi nay h the contacts 1 med by continuing the I hqserics fieldwinding ,Ihe motor .is new con;

l lo

the controller isreturnedjto the offf'position, 'incircuit of, the coil-oitherelay D and causing the.con-

t'act' member d to drop. The motor armature is thus short-circuited while the shunt fieldi sstill excited, and themotor operates as a braking generator, bringing the machine tore'st smoothly. After the relay has once dropped it cannot be again energized until orderito enable the Contact S'to again engage contacts 1 and2 and thus complete theactuatingcircuit for the relay; By'this'fineans it becomes impossible for.

the motor to be" stopped through the operation of one of thefpush button's'fand then inadvisably permitted to start up againwithout suificient resistance protection.

It is sometimes desirable to be able to operate a machine, such as'a printing press, through small steps while adjusting'the paper or testing'the machine, without requiring the operator'to use the. main controller which may be inconveniently situated for this purthe fnlotor to pose. I Therefore I have provided an additional circuit for the actuating coil of the relay whereby, when the switch arm 8 is brought into engagement with contact 8*, current mayvflow iromlin'e L, through the actuating coil of the relay D, through switch members 8 and 8 through any one of a number of normally open push buttons G," G, G, arranged in parallel, to line L. The push buttons G, G, G, are arranged about the machine at points fro it be convenient to control j the machine intermittently. In adjusting the paper, orf'wh'en it is desired to otherwise run the machine slowly'and intermittently while the operator is watching it," the switch -aim-$ is moved into engagement with contactfi, the main controller is then moved to a positiongiving the proper speed for such operation, and the nearest one of the push buttons G, G, G, is firess'edand held down as long as it is do sirmltd have the machine run, whereupon the push button is' released and themachine immediately comes in rest. This operation may of course be repeated indefinitely. When themachine is ready to be set in continuous operation, the switch-arm s is .moved into engagement with contact s" and the controller must then be retur'ned'to its off position in order to energizc ihc relay d. The motor is then controlled in the usual way from the'm ain controller. r

In Figs. 2 'and 3 I havefillustrated the contacts 1, 2 and 3; 1 and 2 comprisingspring fingers fixed in position within the controller, and the contact 3 being an elongated strip adapted bridge the fingers 1 and 2 and carried upon ,a block of. insulation 12, suitably mounted upo rthef pntroller shait 13. In 3 the parts are shown'in' the position! When the shaft l3 is turned inn-clockwisedirection contact 3- comes into engagement witli'thc fingers "1 and 2 and deflects the outer ends thereof" until finally, when the controlleris-in its-.firstrunning position, the fingers snap past ,thc -dgo of the contact 3 and the electrical connection brwween'th em is interrupted. Upon returning.

contact piece 3, so that the relay-actuating circuitis not completed iexcept during the rotation of the controllef from the -off positio'ntoward the first running position.

"- It will now be seen that the present invention provides means whereby an electrically-operated machine may be started easily and 5brought to rest quickly and smoothly, ibgether with a safe and convenient system of auxiliary control wherebythe machine may be stopped in case of emergency or otherwise and operated intermittently without making it necessary for the operator to' manipulate the main controller.

"What I--claim as new and desire to'secure by Letters Patent of the United States, is,

1. In a system of control, a motor, a controller forsaldmotor, a switch in the motor circuit,electromagnetic-com trolling means for' said switch, a control circuit extending from said controller, a second control circuit provided with one or more normally-open switches, and means for conmeeting said electromagnetic eontrolling means" in either. of said control circuits and disconnecting it from the other control circuit.

2. In a system of control, a' motor, a controller for said motor, a switch in the motor circuit, in eiectromsgnet con- ,trolling said switch, one or more normallyclosed sv'vitchiao in-series with shid electromsgnet, a controicircuit extending from said controller, .a. second-control .circuitprovided with one or more normally-open switches, and means for connecting said electromagnet and said normally-closed switches in either of said control circuits and'disconn'ectf' ing them from the other control circuit. 1

3. In a system of control, a motor,"a controll'er-tor said motor, a normally-open switch in the motor circuit, an

electromagnet adapted'to close said switch when energized, one or more normally-closed switches in series with said electromagnet, a control circuit governed by said controller,-

a second control,circult havlng'a plurality of normallyopen switches arranged thereinin parallel with each other,

and a switch arranged to connect said 'eleetromagnet and said normally-closed switchesin either of said control cir- 'cuits and disconnect them from the other control circuit.

.4. In a system of control, a motor, a controller, a twop osltion switch in the motor circuit and cooperating withthe controller to connect the motor to a source of current supply in one or its positions and to short-circuit the motor armature "in its other position, electromagneticactuating means for said switch, a control circuit governed by said 1 controller, a secondncontrol circuit provided with a plurality of switches, and means for connecting saidactuatfrom the other control circuit.-

In a system To! control, a motor, a controller having otl.""and running positions, a. switch in the motor cir: cult, electromagnetic-controlling means for said switch, a control circuit for energizing said controlling means, coning means in either control circuit and disconnecting it.

tacts in the controller adapted to complete said control circuit in turning the controller from the off position to the first runniu 'g-positlon, means associated with said iswitch controlling-means for completing a-maintaining circuit toritselt independent of the controller contacts,

and one or more normally ciosed switches in said maintliin lng circuit Ior detnerglsihg said. controlling means.

6, In a system ofcontrol, 'a motor, a controllerhaving oi! and running positions, a switch in the motor circuit,-

electromagnetic-dctuetihg means for said switch, one or more switches for deeper-sizing said actnating'menns, a

control circuit und'contacts'therein adapted 'to be closed in moving the controller from the oflf position to the iii-st running position, means associated with said nclu ut ing means for completing a maintaining circuit independ; ent of said circuits, :1 second control circuit provided with one or more switches, and means for connecting said actu ating means in either control 'circuit and disconnecting it trom the other control circuit. 7

7.- In combination, a source of current supply, a motor having an armature and a shunt field winding, a main resistance, a field resistance, and means for connecting said main resistance to the source of supply with the motor armature in shunt to variable portions thereot and then connecting the armature directly to said source 0! supply and inserting resistance in the shunt field.

8. In combination, a source of current supply, a motor having a series field winding and a shunt field winding, a resistance, and means for connecting said series field winding to said source or supply' in series with said resistance with the mni'filf armature in shunt to-variahle portions oi! said'resistance and then cutting out the resistance and series field and connecting the armature directly to the source of supply.

9; In combination, a source of current supply, a motor having a series field winding and a shunt field winding, a

resistance, and means for connecting said series field winding to said source of supply in series with said resistance .and with the motor armature in shunt to variable portions of said resistance and then cutting out the resistance and series field, connecting the armature directly to said source of supply and varying the strength of the shunt field.

In witness whereof, I have hereunto set my hand this 26th day of February, 1906. v

HAROLD E. WHITE. Witnesses:

BENJAMIN B. HULL,

HELEN Onronn.

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