US2285229A - Control system - Google Patents

Description

June 1942- F. M. ROBERTS ETAL 2,285,229

CONTROL SYSTEM Filed June 29, 1940 2 Sheets-Sheet 1 Inventors- Frederic MRoberts, Lucius A. Norris,

- Their ttorneg.

J1me 1942- F. M. ROBERTS ETAL 2,285,229

' CONTROL SYSTEM Filed June 29, 1940 2 Sheets-Sheet 2 Pig. 2.

Man =5: ffflS'ZW/VCZ" I I I i a F l I l l r W inventors I Frederic M. Roberts, Lucius A. Norris,

b Wan/ y Their Attorney.

Patented June 2, 1942' CONTROL SYSTEM Frederic M. Roberts and Lucius A. Norris,

Schenectady, N. Y., assignors to General Electric Company, a corporation of New York Application June 29, 1940, Serial No. 343,256

8 Claims.

This invention relates to control systems, more particularly to systems for controlling the winding of a predetermined length of material on a roll, and it has for an object the provision of a simple, reliable and improved control system of this character.

Certain materials such as paper towelling, and toilet paper are unwound from a large supply roll, perforated to form sheets and are then rewound on rolls which are offered for sale with a statement on the roll wrapper that the rolls contain a predetermined number of sheets. For example, rolls of paper towelling usually contain 150 sheets and rolls of toilet paper usually contain 1000 sheets. The rolls must contain at least as many sheets as the number stated on the wrapper, but any excess over this number represents a loss to the manufacturer. Consequently, a further object of the invention is the provision of means for accurately counting the number 'of sheets on the roll.

If any time is lost in winding a roll a maximum economy in production is not realized. A large factory may produce many millions of rolls of the product in a year. Even if only a few seconds of time be lost in the winding of each roll, the total loss for the year becomes a very large and important item. Accordingly, an object of the invention is the provision of means for winding the exact number of sheets on the roll in the minimum possible time consistent with the maximum winding speed and the maximum permissible rate of acceleration and deceleration. Stated in other words, the roll must be accelerated at the maximum permissible rate, operated at the maximum permissible speed until such time in the winding operation that deceleration beginning at such time and continuing at the maximum permissible rate will stop the roll with the exact desired number of sheets on the finished roll.

At the present time, even in the most modern manufacturing plants, the counting of sheets on a roll is done by operators who observe a counting device and use their judgment as to the correct instant for initiating the deceleration. Even the best operators do not succeed in stopping the roll at the instant when it contains the exact desired number of sheets. If the roll stops with too many' sheets a loss results, and if it stops with too few sheets the drive must be restarted and again stopped, which introduces a time loss and when stopped the second time the roll may contain too many sheets which results in a material loss in addition to the time loss.

Accordingly, a further object of the invention is the provision of a control system of the character described in the foregoing in which the deceleration and stopping operation is entirely automatic and errors resulting from human judgment are eliminated.

When the supply roll is full its inertia is rela-- tively large and snap oil" occasioned by too rapid acceleration rates occurs frequently. This, of course, results in a loss in material and in a loss oi the time required for rethreading as well as of the time consumed between the finish of the previous roll and the time of the snap off. Also. if the rate of deceleration is too great a loop is formed between the suppl roll and the winding roll and this loop may come in contact with the floor and thus result in another loss of time and material.

Accordingly, a still further object of the invention is the provision of means for limiting the acceleration and deceleration to maximum permissible rates.

In carrying the invention into effect in one form thereof, an electric motor is provided to wind the roll. This motor is supplied from an adjustable voltage generator. A limit switch driven in accordance with the travel of the material operates to weaken the field of the generator to initiate deceleration of the roll drive motor when a given amount of material is wound on the roll and operates to disconnect the gen erator field winding and to reconnect it to the armature with reverse polarity so that the roll drive motor will be brought to rest when a predetermined length of material containing the exact desired number of sheets is wound on the roll.

For a better and more complete understanding of the invention, reference should now be had to the following specification and to the accompanying drawings in which Fig. 1 is'a simple, diagrammatic sketch of winding apparatus of the character described in the foregoing, Fig. 2 is a simple, diagrammatical sketch of an embodiment of the invention, Fig. 3 is a sketch of a detail of the invention, and Fig. 4 is a chart of operating characteristics which facilitate an understanding of the invention.

Referring now to the drawings, a strip of material [0, which may be assumed to be paper towelling, is unwound from a full supply roll H and is passed through a tensioning device comprising two idler rolls [2 and I3, and a weighted roll I which rides in a loop formed in the material between the idler rolls [2 and I3. From the tensioning device, the material is passed over an idler roll I5 and then through a device It which perforates the material inindividual sheet driving means such as an electric motor I8. As

shown, this motor is supplied from an adjustable magnetic contactor 3| is provided for controlling the connections of the generatonshuht field winding I90 and of the armature of the flywheel dynamo-electric machine 255. When the contactor 3| is operated to its upper position the generator shunt field winding [90 is connected voltage generator I9 which in turn is driven by a suitable driving means such as an induction motor (not shown) at a speed which is preferably substantially constant. The generator I9 is provided with a commutating field winding [9a and a series field winding I91 and is also provided with a separately'excited shunt field winding I90. The

generator field winding I90 is excited from a suitable source cfexcitation such asthe excitation busses 2D and 2| whichare supplied from an exciter 22. A rheostat is connected in circuit with the separately excited field winding '90. This rheostat serves to adjust the maximum armature voltage of-the generator I9 and therefore the maximum speed of the motor i8, which is supplied therefrom, to any desiredvalue.

For the purpose of limiting the rate of rise and decay of the'flux of .the generator field II: and therefore the rate of acceleration and deceleration of the winding motor I8, to a maximum permissible value, an energy storage device is provided. "This energy storage device may take the form of a dynamo-electric machine 25a having its armature terminals arranged to be connected in parallel with the separately excited. generator shuntfleld'winding I9e. also provided with flywheel capacity for storing mechanical energy. The dynamo-electric machine 25a is illustratedjas being provided with an'external flywheel 25s but it will be understood of course, that the flywheel may be built into the rotor of the dynamo-electric machine The dynamo-electric machine 25a is provided with av separately excited shunt field winding 25 which is connected to the excitation busses 20 and 2|. During the rise of magnetic flux in the generator shunt field winding I9e, i. e., during acceleration of the roll winding motor 18 the dynamo-electric machine 25; operates'as a motor and stores energyin the flywheel 25s. A variable resistor 26 is included in circuit with the field winding 25 and this variable resistor serves to adjust the maximum speed of thedy-' namo-electric machine" 255 and therefore the amount of energy stored in the flywheel 25b to any desired valuewithin a wide range of values.

A pair of adjustable resistors 21 and 2|! are provided and are arranged to be selectively connected in the circuit of the generator shunt field winding I9: under certain operating conditions by means of a selector switch 23. The resistor 21 has a low resistance and the resistor 28 has A switching device illustrateda an electro- It is across the excitation busses 20 and 2| and the armature of the flywheel dynamo-electric machine 255 is connected in parallel with the generator shunt field winding I30, whereas when the contactor 3| is in the dropped-out position in which it is illustrated, the generator shunt field winding I90 is disconnected from the excitation busses 20 and 2| and is connected across the armature terminals of thegenerator with reverse polarity and the armature of the flywheel dynamo-electric machine 25.. is dlSCOXl-r nected from the generator shunt field winding.

In order to provide short inching or jogging. movements a jog relay 32 and a jog" push button. type switch 3 controlling the energization of the operatingcoil of the jog relay are provided. When the jog switch 33 is depressed, the jog relay 32 is picked up and this in turn causes the field relay 3| to be picked up to connect the generator shunt field winding |3e to the excitation busses 20 and 2| with the high resistance resistor-23 included in circuit so that the generator generates a very low voltage and the winding motor I8 is caused to operate at a steady slow speed.

For the purpose of counting' the number of In Fig. l, the limit switch is illustrated as being clutch solenoid 31 (Fig. 2) is deenergized. Limit switch 34 is also provided with a supporting casing 38 and a cover 39 which also acts as a supporting member for certain parts of the limit switch. A pair of micro-switches 40 and or other suitable contacts are mounted on the cas ing 38 as shown in Fig. 3. Since the structural details per se of these switches constitute no part of the present invention, only the casings of these switches are illustrated in Fig. 3. However, the micro-switch wis'provided with a pair of normally closed contacts 40 and micro-switch 4| is provided with a pair of normally closed contacts Ma (Fig. 2). It will be noted that a pin 40:; of switch 43 projects through the casings into contact with a spring lever 40b. Whenever the spring lever We is displaced by an amount as smallas .001 inch, pin It moves sufllciently to separate the contacts 40-. Although not shown, it will be understood that the contacts of the micro-switch III are of the over-center snap action type. Switch 4| is also provided with pin in, and a spring lever Me which are identical with the corresponding parts of switch u. is will be noted; that the casings oi the switches 4| and 4| are. pivotally mounted so that each oi these switches canbe rotated out of the vertical position in which they are illustrated against the action of springs 42 and 43, respectively. A pair of screws 44 and 43 are threaded through the cover so. that their axes are parallel to the longitudinal axis of the rotatable splined member 33. A pair of nuts 44 and 41 are threaded on the screws 44 and 43, respectively. These nuts 46 and 41' are provided with external gear teeth which mesh'with the splines on the rotatable member 33 so that the nuts 44 and '41 travel along the screws 44 and 45 in response to rotation of the splined member 35. At a predetermined point in its travel along the screw 44, the nut 49 engages the spring lever 40 and causes the contact 49. toopen. Similarly, at a predetermined point in its travel along the screw 45, the nut 41 engages the spring lever 4| and opens the contacts 4|. It will be noted that the heads of the screws '44 and 45 are recessed to provide more adjustment by means of a screw driver.

At the .beginning of the roll winding operation, the nuts 46 and 41 occupy the dotted line positions indicated in Fig. 3. As the winding op- 1 eration progresses thenuts 4G and 41 are driven by the splined member and travel to the right,

to engage the spring levers and 4|e to effect deceleration and stopping of the roll winding motor l8. Limit switch 34 is provided with a spring member 49 which is wound up by the rotatable splined member 35 during the progress of the winding operation. When thewinding operation is completed and the clutch solenoid 31 9|, through normally closed contacts 4|; of the is deenergized to effect disengagement of the clutch, the spring 48 returns the rotatable splined member 35 to its original position and consequently the traveling nuts 46 and 41 are returned to their original positions which are illustrated in dotted lines in Fig. 3.

with the foregoing understanding of the elements and their organization in the system, the operation of the system will be readily understood from the description which follows:

It is assumed that the exciter 22 is being driven at normal speed and is generating its normal full line voltage. The end oi the paper III is secured to the winding roll H. To start the winding operation the start" button 39 is depressed to close the contacts 39.. This completes limit switch to the side 2| of the excitation source. -Relays N and 4| in responding to energization close their normally open contacts 99b,

c, and We and 5h, ils and 5|d, respectively. Contacts 90 in closing complete a holding circuit for the operating coil II]. in parallel with the contacts 29 so that relay 50 will remain picked up if the contacts 29c of relay 29 are subsequently opened. Similarly, in the closed posi- -,tion of contacts 5| a holding circuit for the operating coil 5| of relay BI is established in parallel with the contacts 294 so that relay 3| will remain picked up after the contacts 294 are opened. Contacts We of relay 50 and contacts 9| of relay 5| cooperate to complete an energizing circuit for the operating coil 3|. of the generator iield contactor 3|. This circuit is traced from the side 20 of the excitation source through the normally closed contacts of the jog push button 33, contacts 5000i relay 50, normally closed contacts 32-. of jog" relay 32, contacts 5|b of relay 5|, operating coil 3|. oi'the iield contactor, through normally closed contacts 4| of the limit switch to the side 2| oi the excitation source.

Field contactor 3|, in'responding to energize tion, opens its normally closed contacts 3h; and 3| and closes its normally open contacts 3|a, 3|, Contacts 3|a in their closed position connect the armature of the flywheel dynamoelectric machine 25. in parallel with the separately excited generator shunt field winding Us. At the same time contacts 3 I, and 3 I: connect the generator shunt field windings |9e to the excitation source 20 and 2| through the low resistance resistor 21 and the speed rheostat 24 which has previously been adjusted for the maximum operating speed of the winding motor It. The flux of the generator field winding |9b begins to rise and continues to rise at a rate which is dependent upon the electrical constants of the generator shunt field circuit and the mechanical and elecg the splined member 35 begins to rotate. In conan energizing circuit for the operating coil 29- of the selector switch 29. This energizing circuit is traced from the side 20 of the excitation source through the "stop" push button switch 49, contacts of the start push button switch 39, oper--, ating coil 29. of the selector switch 29, normally closed contacts 40- and 4|. of limit sw tch mechanism 34 to the side 2| of the excitation source. Selector switch 29 in responding to energization of its operating coil closes its normally open contacts 29h, 29, 29a, and 29. and opens its normally closed contact 29:. In the closed position of contacts 29s, a holding circuit for the operating coil 29- is established in parallel with the contacts of the "start push button 30 which may now be released. Contacts 29s when closed complete an energizing circuit for the operating coil 30. of a sequencing control relay 50 through the normally closed contacts 4|. of the limit switch. Similarly, contacts 29a in closing complete an energizing circuit for the operating coil 5h of another control relay 9|. This circuit is sequence of the rotation of the member 35, spring 49 begins to wind up and the nuts 46 and 41 begin to travel to the right along threaded screws 44 and 45. The electrical constants of the generator shunt field winding |9e and the mechanical and electrical constants of the flywheel dynamoelectric machine 25a are so chosen that the acceleration of the motor I9 is limited to a maximum permissible value. This acceleration to the maximum operating speed is represented graphically in Fig. 4 by the portion 52 of the curve whose ordinates represent speed and whose abscissae represent time. when the acceleration is at the maximum permissible rate, the maximum operating speed is reached in a minimum time. Thereafter, the winding operation continues at maximum speed as represented by the flat portion 53 of the curve in Fig. 4. As the winding operation continues, the splined member 35 continues to wind up the spring 49 and the nuts 46 and 4! continue to travel to the right.

At a predetermined point in the winding operation, which is represented by the point Tl on the graph in Fig. 4, i. esiwhen a given amount oi the material II is wound on the roll l'| the traveling nut 48' strikes-the spring lever 40h, with the result that spring leverr'. moves to the right and presses'on the pin 40 which separates the con tacts'. oi the limit switcln. As a result of the opening of ,contacts 48., the (operating. coil 28-.

of selectorswitch' 28 is deenergized and this switch opens its normally open contacts and closes its normally closed contacts 28:. Relays 80 and SI whose energizing circuits were completed through contacts 29 and 28 of switch 28 do not drop out since their operating coils remain energized through holding circuits established by their own auxiliary contacts 80 and 8h respectively. v

When contacts 29. are open the low resistance resistor I! is removed from the circuit of the generator shunt fleldwinding Us and when the contacts 29: are closed the high resistance resistor Z8 is inserted in the circuit of the generator shunt field winding. As a result of this the field strength of the generator is weakened and deceleration of the winding roll motor I8 is initiated. With respect to the decay of exciting current in the generator shunt field winding I80 the flywheel dynamo electric machine 25,. operates to limit the rate of decay of flux in the following manner. The exciting current of the field winding '90 tends to be maintained 'not only by the action of its own self-induced counter E. M. F. but also by the counter E.M. F. of the flywheel machine "25. which is now driven as a generator by the kinetic energy stored in its own armature or flywheel. As a result, it serves in large measure to controlthe rate of change of excitation of the winding la. during the period of decay and prolongs the decay very substantially in comparison with that which would be provided solely by the electromagnetic stored energy' of the'winding We.

The running light current of the dynamo electric machine 25a when operating as a motor being *very small and the resistance of its armature also being very small, the initial counter E. M. F.

of the motor 253. at the instant of opening the switch contact 290 is practically equal to the IR. drop of the field winding I8c. Hence the selfindu'ced voltage of the field winding I9: is very small at this instant and as a result the initial rate of decay of its exciting current is also very small. It will thus be seen that the kinetic stored energy of the motor 25s-and its flywheel 25:; supplies most, of the energy and excitation during the initial part of the decay. As the motor 25's slows down,'its counter E. M. F. decays quite rapidly thus permitting the rate of decay of the exciting current of winding I90 to increase. This, however, causes the self-induced voltage of the winding I9c to increase which in turn acts to restrict the rate 'of decay oi flux of the windlng I8 so that it is less than proportional to the decay of the counter E. M. F. of the motor 25a- The total effect then is that the decay of exciting current in the field winding l0 begins at a very moderate rate, rises quite gradually to a ill . anism34 is left in a reset condition for a subsethe graph by the sloping'portlonwfl oithe speed.

the motor 18, the traveling nut 48 continues to travel toward the right on the threaded screw 44. Theswitch casing of the microswitch 40' pivots-in a clockwisecurve. I v

I During the deceleration oi direction about its pivot to permit the nut 48 to continue its travel during the deceleration.

The deceleration oi the winding roll motor" continues until a point T2, in the operationis reached at which the speed oi the motor is almost zero and the number 0! sheets wound on the roll I1 is almost'the desired exact number. At this time T2, traveling 'nut "strikes the spring lever Me and causes it to move to the right to push on the pin 4| so as to open the limit switch 1 contacts 4h. Contacts 4|. in opening interrupt the energizing circuits for the operating coll 3h. of the field contactor 3|, andcontactor Si in re-v sponse to deenergization opens its normally open field winding Hate the armature terminals 01' the generator I! with reverse polarity so that the armature voltage of the generator tends to cause current to flow in the opposite direction through the shunt field winding '91:. As a result oi. this the fiux of the shunt field winding we decays very rapidly towards zero. Likewise the, armature voltage of the generator l9 decreases rapidly towards zero. When the flux of the field winding I90 reaches zero value the voltage of the generator also reaches zero value and consequently this reverse connection does not cause a the generator field to build up in the reverse direction.

The decrease of the armature voltage to zero also causes the speed of the winding roll motor W to decrease to zero and this new speed oi the winding roll motor I8 is reached when the exact desired number of sheets of the material Hi are wound on the roll II. It will be understood, of course, that several trial-adjustments of the screws 44 and 45 may be necessary in order to position the traveling nuts 48' and 41 sothat they will initiate deceleration at the proper time to stop the roll I'l when it contains exactly the desired number of sheets. 1

The opening of contacts 5la/deenergizes the clutch solenoid 31 and this results in disengaging the clutch 36. When the clutch 36 is disengaged, the spring 48 which was wound up by the rotation of the splined member 35 is now freeto rotate splined member in the opposite direction. As a result, the spring 48 rotates the splined member the exact number of turns in the reverse direction that it was rotated in the forward direction during the roll winding operation and consequently when the spring 48 is completely unwound the splined member 38 will be in its origi nal position and likewise the traveling nuts 48 and 41 will be in their'original positions. As the nuts 46 and 41 back away from the micro-switches 40 and 4i the springs 42 and 43 return to their original position and thus the limit switch mechquent operation.

When limit switch contacts 4 I. open, the energizing circuits for relays 88 and 5| are interrupted and these relays drop out thereby to restore the .system to its original condition so that it is for a subsequent winding operation.

LLUDdGl'i eertainvonentml conditi ners dedirablefi to stopzthwwindinm somt ontatazan intermediate-point; the; cmnpleteynumbex: ofisheetsds pitched-i depressing button-Matador tempt a:en--, operatins eoiitoiaeontactorsaz .m-hm miitokdecnemt tion;: connector drops. miiztoziopen zcontoctssrllu" and ciosez eontacin montactstllaninioncnins remove low 7 cc redstor from :the

circuit of the. generator :shnntmelmwindinmJh andteontactsziai in closing inscrtthehigh resistance resistor; 28: in?) the eir'cuit'riotathea'meraipr shuntl winding l'e" tosinitiate1the :;decelera1 stony, button lifzalso ;inter:-;

rupts' the energizing circuit operating-coil 50: ot'azrelayigilhranda this wrelay vresponse :to deenergization r'opens'filn inormallnzropenedeoontacts :Ms; 5. (Lontactnsfla'zinion'ening limited thereto since alterations and modifications readily suggest themselves to persons skilled "i'n'the art without departing from the true spirit e; scope or the anas new a des e to s u by Letters atentiotthe United S t itrAazaontrolt-systegn for;apparatus for winding 'of {material on a roll com- ;,etectri'c-'-;.-motoxrtierscontrolling the windinmoi; saidon roll. an adjustablefs voltage-generatot iorisimplying said motor,

aisii'mit t 'switchiactuatediaccordance with the travel'zotisaidz materieiwtorgweakening the field of 'said sg'enerttor therebyito deceleration of saidi-motomvhemaipredetermined amount oi said materialiisrwound-auponzsaidroll and for further weakeningwsaid generator-field to effect stopping do-rnoti interrupt the::2. rcircuit :Ior ==the operating-coil?! more thexneid .oontactor tlrssince the icontacts Mia area-pamileledp; byg; the zcontacis 55; of. the counter voltage andzthe. tactsf-lik arewbridged by: the. movableseontact member'aor this relaywhicn?is' held-iimits-supper position Jas long as'a'the counter-voltagez-rof the 7 motor "I 8 is greater :thanfla predetermined value; i sooni as the! deeleration ot; the :motor'in Isl reachessuchapointwthatfiitsfcounterevoltage e,

creases: F'below I this; =prcdetermined; ;value;;-ithe countenvoltage 're'lay drops out and-::opens contact :55. therebyi toimterrupt the'lenergizing circuitljior'cthe I operating {0011! olzfielii cohtactor '31 "In response-to =deenergizationz-i contactor ;,3:l

disconnectsthe generator shunt field iwin'ding .195 Z:-

i'roi'n "the eiicitation' 'sonrce 20 'alndiil and?reconnects it to the generator armaturewith reverse polarity to eiiect' thjei final stoppinggofitheimotor thatidescribe in the 7 same; manner foregoing.

when ui st-5min. mammals,

theen'ergizing' circuit .ror thef operanng rcoil ma oi irelay 5i 1 :is not mammalian: consequen 1y the clutchrsolenoiwnewnot-:deenersizedi' a resultttherez; no resetting fofathe i limit Fswtic" rnechanismraii suciaasoccurs?whenthe decelera tionij-and'. stopping ccofunwindingroll m'o fito interrnpti'the":windingiioperation'g the whenia .diflerent-.:predetermined amount or said material \is wound onsaidroll; and means responsiveatotthe'lastmentioned operation of said sucoeedhigz.operation.;sw;

;.:2.-.in: ont oi' sy emtonemen for winding aspredeterminedpiens hzzoit a on a l comprisingsin combination van electric motor for driv nsiisa omunnlyins said o d atoltha ml fleldawindi aaatlimi switch having a iLrotatabIe member connected to be driven in limitsswitch for resetting said limit switch for a accordanoeiwith the-travelzoixsaid material, an

electromagnetic clutchin thedriving connections Di'seaid rotatablemembenicaoontadt and a m mberzidrivensbyisaidrotatable-member ior actuating said contact when a,-;giv,en: length of said matenialiisiiiwoundaomsaid [Gulf-, second contact and meansi'drivenabylsaidrrotatable member for actuating saidasecondzzcontactawhen a different givenz.:lengths i materialiis; wound on said roll,

andwfazspringlzasonnectedr-tozsaid.rotatable memberxfmdearvanged "to; bebwo'und up in response tozrotationlzomsaid'rotatablejmember, means re sponsive' rto actuatiomzzoivfsaidxfirst' contact for initiating eceleration-tof saidpmotor, and means- .i-esponsivefktoilactnationz of;::said second contact ionzw disconnecting'isaidmgenerator field winding said'rfield-iwinding to the armaturezofisaidvgeise'ratora in reverse: polarity thereby toxefieet:stoppingxrotirsaidpmotor when said predetermined lensthe'ismoundzon-said roll and for .de itsaidmlutchstop-provide for return =of; siidvrotatablezmembuvandjsaid driven member r'iorigin alrpositions'. :z-r-z sbperaticri can begresumed' by depressing" he start bed in the foregoing.

Altholihhi'in' raccordiiiewim the provisions of the patent statutes this invention is described as embodied in concrete form and the principle thereof has been described together with the best mode in which it is now contemplated app ng that principle, it will be understomth the elements and apparatus shown and described are A tcentrolzssystein Zion for winding .anpredeterniined material on a roll comprising in combinatiomameiectric motor for driving saidrawindingsroll anfiadiustabl voltage generatorvzfomsupplyingzsaidismotor, said generator-cbeingaiprdvidedvwithzaifieidewinding, a resiston havingealow resistance a :rsistor'haying relatively lhighzcresistanceg control device and :means iresponsiyelto:'operationmf-said control dewiceiri'or't-ienergizin'g said field with said flow. tesistancelzresistorwinacircuitf to initiate acrationmic-maid motor; aslimitzswitch driven inrsacooodance with *thetravel zoi 'said material isaifli limit 3switchahavingtwoiicontacts arranged to be actnated siiccessivelyg; means responsive to actuation of the first of said contacts to be actuated for inserting said high resistance resistor in circuit wtih said field winding to initiate deceleration otsaid motor when a given length of material is wound on said roll. and meansresponsive to actuation of the second of said conmerely illustrative and that the invention is not tacts for disconnecting said field winding and .lwindingjroli g n tadjustable voltage a predetermined length of material on a roll comprising in combination an electric motor for drivingsaid winding roll,-a control device and means responsive to operation of said device for initiating acceleration of said motor, a limit switch device having a .splined rotatable member connected to be driven in accordance withthe-travel oi said'material, a clutch-included in the driving connections to said rotatablemember, a

' spring connected to be wound up in response to rotation of said rotatable member, a pairfol threaded-screws. a'nut threaded to each screw and having gear teeth spline or said rotatable memberthereby to provide for axial movement or said nuts along. said screwsand a pair of contacts arranged to be successively actuated by said nuts, means responsive to actuation of the first of said contacts to. be en'- gaged for initiating deceleration or said motorwhen a given amount of said material is wound on said roll, and meausresponsive to the actuation o'i'said second contact for stopping said motor when said predetermined length of materialiswound on said roll and for disengaging saidvclu'tch to provide ior reverse rotation of said splined rotatable member to return said nuts to their ori n positions. v

' v 5. A controlflsystem .i'or apparatus for winding a predetermined length of material on a roll comprising'in combination an electricmotor for; 1 driving said roll. an adjustable 'voltage'generator for supplying said motor, said' generator- -being provided'with a field winding,a starting control device for energizing said field winding to initiate acceleration oi said'winding motor, a limit switch driven in accordance with-the travel of said length of material for weakening'the field oi said generator to initiate. deceleration of said motor when a given length oi'material is wound von said roll and for disconnecting said field winding and reconnecting it to the armature in r'e-- verse polarity to effect stopping at saidmotor when said predetermined length of material is wound on said roll, and an energy storage device connected to said field winding for the rates of rise and decay of the fiuxgot sajid field winding thereby to limit the acceleration-and deceleration oi said motor.

6. A controlsystem' ior apparatus for winding a predetermined length of material on a roll, com-- prising in" combination an electric" motor connected to drive said roll, an adjustable voltage generator for suplying saidmotonsaid-generator having a field winding, a starting control device and means controlled thereby for energizing said field winding to initiate acceleration of said motor, a limit switch driven in accordance with the travel of said material (or weakening the field 01' said generator to initiate-deceleration of said motor when a given length said -mate-' when said prede 2,285,220 k e i- A I firialis woundonsaidrollandfior;

said neid indingndi-eeunnectingit to u'iearmature terminals of saidfgenerator withrree of t v of wound on and-IadynamoeIectria -ma j chine connected to winding verse polarity 'tojeifect vlded witha mechanical stonse' d vic I for limiting. the fat andddmym 7 fiux of said generator therebyito'limit or said acceleration '1. A control system idiapparatus for d a predetermined length of material on a roll.

prising in combination ian electric motor,.--caisaid field winding to initiate acceleration nected to drive said roll an adjustable generator for supplyin motor; said generator'having a field a-starting contmfds vice and means controlled thereby for motor, a-limit switch driven in accordance with the travel or said material for weakening the 7 said motor when a given of said material I ture terminals or saidflg'enerator with field of said generator to initiate 0! is wound on sald'roll.and.ior..disconnecting.said field winding and .reconmc'ting it to the armapolarity to efiect stopping or said motorwhen said predetermined length oi material is wound on, saidrolL-and-a dynamo electric machine coning the'decay oi thereby to limit the nected to, said and provided with flywheel capacity-for the storage of mechanical energy during Jot flux o1 saidgenerator field for'sgiving up said energyxdur-k rates oi of said flux and the rates 01" said acceleration and deceleration of said a predetermined length "of; material on a roll 1 motor; d

'8. A control system for apparatus for winding comprising in" combination an adjustable voltase generator-provided with a-field winding and a motor supplied i'rom said generator i'or'driving said roll, a limit-switch device driven in accordance with the travel of. said material iorwealrening the excitation of said field winding to initiate a deceleration of said motorwhen a given amount of said material is wound on saidroll and for .disconnectingsaid field'winding and reconnecting it to the armature terminal ot'said generator with reverse polarity to eflect stopping oi said motor when said predetermined length of material is wound 'on said roll, a manually operated control device and means controlled thereby forweakening the. excitation of said field winding to initiate deceleration of .said motor at any time prior to operationoff'said limit device, and a-relay havingan operating coil eher giz ed'by the voltage existing at the terminals or said motor for disconnecting said gene'raton field winding at a predetermined motor speed and reconnecting said field winding to themture terminals oi said generator with reverse polarity to effect said motor.

, c mnosnnrs. "LUCIUB a.

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