US2439949A - Control for barrel stencilling machines - Google Patents

Description

Apr/il 20, 194.8. .1. E. ROBLEE 2,439,949

CONTROL FOR BARREL STENCILLING MACHINES Filed sept. 24', 194e Patented Apr. 20, `1948 UN I l ED STATE GFF I CE 25439g949'? CONTROL FOR BARREL s'rENer'LLINdY MACHINES! J olinl E. Roblee,Pitt'sburgh, Pa., a'ssgnoritoWes-tinghouse Electric Corporation, East Pittsburgh;y

Pa., a corporation of Pennsylvania;

Application September '24, 1946; Seral No; .698;971

5 Claims;

position of the respective members.

More particularly this invention is directedto an apparatus for automatically stencilling bar-- relsin which a member'isutilizedto'pickup.said barrels, position said barrels for stencilling operation thereon by a stencilling member and? there- 10'* after discharging said barrels5 the stencillingf member comprising a stencilling screen movable first in one direction acrossk a properlypositioned barrel and upon the positioning of asecond bar-A rel for stencilling being movable in the opposite l5:

direction across said second' barrel, electricalinterlocking between said stencilling member and saidibarrel pickup member being utlize'dito'fa-uto matically control the alternate cyclic operation of said members. 20

Generally, itis an object of this inventiont'oi provide an automatic barrelstencilling machine.-

Another object of this inventionlisV to provid@ a control arrangement for controlling the-opera'-4 tionof a: pair of members tolbe alter-nat'elyfop-Y 25' erated in which each ofA said1 members, at* thel` limits of movement of each` thereof, are operableto initiate' operation of the other of" saidmem-f bers.

A- further object of this'invention-istoprovide' 3 a system oi electrical control'which is simple inv its elements and positive-in operation; A

The foregoing objectsaremerely illustrative of the variousV aims' and obje'ctsof this invention.

Other objectsv and advantages will be'comeappar-r 35 entl upon a study of the' followingi specification When'considered in conjunction with theaccomlpanying drawing, in which, the single' figure` thereof illustrates a system of electrical controlL In the drawing, the elements' of. thebarrelst'enl cilling machine which are to be controlledare diagrammatically illustrated; These. elements include a yoke l constructed and'-arrailgedto.pickL uploarrels 2, the yokebeing driven by af motor 2M, and a rectangular framework shownfonli in side elevation partly in section anddriveniby; the motor IM, whichv carries astencilling screen-1 l disposedvto contact and stencirthe barrels: 2. The framework 3"is supportedinvsuitable guides,j or. tra'cksinot shown) which permitm'c` vement` of thev framework in the. forward? and,v reverse? directions, respectively; left and right: asLV-iewe'df.y in thedrawing.' The. framework isinzits intere` o 2i mediate postionindicat'ing-that a stencillng oper'ationi's' inprogress;

The electrical elementscomprising the system for' controlling the' motors` IMv and 2M and thus controlling the movements or the yoke l and the framework 33 include the limit switches Ll and LZIOperaltedby the dogs-5'I and 6 on the frameworky 32' thelimlt s-witches'L3`1 and'L operated by the'` cams-lv` and 8 on thesliaft? or motor 2M, the for-ward` and? reverse relays F and R alternately energizedlin" dependence of the position of the framework 3a`t one or the other of its extremes of'niovement' through interlocking circuits of the limltswitches andiwhich'controlr'the direction of rotationofrthe motor IM, the relay B which energize'sith'e:armaturefor themotor 2Miwhenever the framework 3is` in Onel of it'stwo extremes oi' position;` this'-` control of." the motor 2M also being effectedthroughthe limit switches; The control further includestheInchiForward, Inch Reverse and Inch? Barrel' push buttons' which provide presetting; andi inching control of the respeotive positions` of the yoke I` and framework 3,4and1nally the conventional starting control includingtthe switch-NV-,the Start and Stop push buttons; andthe selector switch SS having the twopositionsfRun'` andlnchg. respectively, for automatic and: manual system control. A source of alternating.; current for energizing the system 3- isrepre'sented bythe conductors I0, ll and l2.

Thef'yoke: Iis provide`d1with four arms displaced by 90 each' twofor-ming a cradle in which the barrel rides beneath the-screen. Rollers 9 positionednearthe extremities of. the yoke arms supvporttherbarrel' ini the yoke that barrel rotation may occur by-frictional engagement thereof with the moving screenfduring a stencilling operation. The-extremitiesof the-yoke arms are curved in the'directionof yokerotation to provide suitable embodying the principles of'this' invention; 4oz means for pickirlsupfthe next barrel to be stencilled; With. the-arrangement shown, the barrels-may be fed to-the yoke'by means of a ramp (not shown) sloping into the yoke. For each stencilling: operation, the yoke l is rotated 90 sin thel clockwisedirection. During a normal cyclefone-ba'rrel is engaged bythe curved extremitiesfofathef-yokefarm, anotherris being stencilled anda thirdinotsho'wn). is discharged.

The threefphasealternatingcurrent motors IM 50:: andZM are-:connectedin circuit branches extendinglirom the thre'erphasei alternating current supply representedy by conductors l0; ll and l2. Energizatio'n ofy the motors through these branchesY isi=controlled byrelays.' In the case of 5i motor IM which is to be intermittently operated 3 in reversed directions, reversible energization control is had through the medium of relay F or R, the direction of rotation of the motor, that is, forward or reverse, depending respectively upon which of relays F or R operate. Since the yoke I is to be intermittently operated in one rotational direction only, reversing means need not beprovided. A single relay B is, therefore, utilized to intermittently connect the motor to supply conductors Iii, II and I2. For automatic operation the coils of relays F, R and B are connected in separate lcircuits with certain of the limit switches across the conductors lila. and I2a. For manual operation the coilssof these relays are connected across conductors Ilia and I2b.

Conductor Ia is energized through contacts NVI Y of the no voltage switch NV. Conductors I2a and iZb are alternately energized through contacts NV2 in dependence of the position of selector switch SS. The coil of no voltage switch NV is connected across conductors I and I2 in a circuit including the Stop and Start pushv buttons.

Specifically, the coil of forward relay F is connected in a circuit across the conductors lila and im which includes limit switch contacts L3b and Lia and across the conductors Ilia, and I2b in a circuit including the limit switch contacts Lia and the Inch Forward push button. The coil of reverse relay R is connected in a circuit across the conductors Ilia and I2a which includes theV limit switch contacts LZa and Leb and across conductors Ita and I2b in a circuit including limit switch contacts L2a and the Inch Reverse push button. The coil of relay B isenergized from the conductors lila and I2a during automatic control in a circuit including the paralleled The coil of forward relay F is now energized in a circuit across the conductors ia and iZa including the limit switch contacts Lia and L3b which as shown are closed. Contacts FI, F2 and F3 are, therefore, closed and the motor IM energized to drive the framework 3 in the forward direction stencilling the barrel 2 in contact with the screen thereof. When the extreme of forward movement is reached dog 5 actuates limit switch LI opening contacts Lia and closing contacts Lib. Closing of contacts Lib completes an energizing circuit for the coil of relay B across conductors lila and I2a which includes the contacts Lila and contacts Lib. Relay B picks up pairs of limit switch contacts Lib, La and L2b,

position. Under this condition relays F, R and BV when sequentially connected across the conductors lila. and I2a by the limit switches in circuit therewith are energized, since conductors I2a are now connected to the supply. When the selector switch is in its Inch position the energy supply istransferred from conductors I2a, to conductor IZb. Limit switches L3b, LIIb and the paralleled pairs of limit switches Lib, Lila-and L2b, L3a are.

disconnected from the circuit andv their control effect respectively on relays F, R and B is no longer present. In the case of the stencilling framework the operation now depends upon the manipulation of the Inch Forward and Inch Reverse push buttons with limit switches Lia and L2a yet controlling the extreme of movement in each direction. Relay B is controlled exclusively by the Inch Barrel push button and may be utilized to actuate the yoke to any desired angular position.V 1

As illustrated in the drawing, the various control elements are set so that automatic opera tion of the motor IM in the forward direction will be had. This means that the selector switch SS is in its Run position, as shown. When the. Start push button is pressed to energize the switch NV, the contacts NVI, NV2 and NV3 thereof close.V Contacts NVI and NV2 connect Athe conductors lila and I2a to the source of energizing potential and contacts NV3 shunt the Start I push button and provide a holding circuit for the coil of the NV switch. f

closing its contacts in the armature circuit for the motor 2M. As the motor 2M rotates, the yoke I is rotated discharging the stencilled barrel, positioning another barrel for stencilling and engaging ra third barrel at the curved extremity of one arm thereof. Simultaneously therewith cams l and 3 are rotated. Limit switch L3 is actuated by cam 'I to open contacts L3b thereof shortly after cam rotation begins. Subsequently contacts L3a close. Limit switch Lil remains in the position shown until the yoke has rotated the required to position the next barrel for stencilling.l At this point, a sharp drop in the surface of cam 8 permits'the biasing of the limit switch to its opposite position, opening contacts Lia and closing contacts L4b. Opening of contacts Lila stops the motor 2M by deenergizing the relay B. VIt is to be noted that the cams 1 and 8 are displaced by 90 and that the diametrically opposite halves of each thereof are symmetrical. Thus for each 90" of yoke rotation the limit switches L3 and L4 are reversely actuated.

When the contacts L4b close, the coil of relay R is connected across conductors Illa and IZa in a circuit which includes contacts L41) and contacts L2a. Contacts RI, R2 and R3 now close and the motor IM is reversely connected to the conductors IB, II and I2. Consequently, the motor now runs in a reverse direction driving the framework 3 in the reverse direction. Screen 4 passes across the barrel to be stencilled and applies the stencil work thereto, the barrel being rotated by frictional engagement thereof with the screen. As the reverse direction extreme of movement is reached, the limit switch L2 is operated. Contact members L2a open while contact members L2b close. Opening of contacts L2a causes relay R to drop out and motor IM is deenergized and stopped.V

Closure of contacts L2b energizes relay B in a circuit including the contacts L3a and L2b. Motor 2M rotates until the yoke moves through the required 90 angle at which point the surface of cam 'I is cut back. Limit switch L3 again assumes the position shown in the drawing interrupting the circuit to relay B which drops out and deenergizes the motor 2M. Contacts L3b in conjunction with contacts Lia now pick up relay F and the cycle is repeated as described.

To effect inching movement of the yoke and framework, the vselector switch is placed in the Inch position. Conductor I2b is now energized. Assuming the limit switch LI in the position shown forward inchingrof the framework 3 is obtained by pressing of the Inch Forward push button, which, in conjunction with contacts Lia, energizes the F relay. This inchingr movement ymay continue until dog 5 opens contacts Lia. Reverse inching is accomplished by operation of the Inch Reverse'push button which together with contacts L2a controls relay R. Inching movement .5 f the yoke l is obtained by, operating the Inch Barrel push button. This push buttondirectly controls the energization of relay B and motor 2M to effect inching operation of the yoke I.

The foregoing disclosure andthe showing made in the drawing are merely illustrative of the principles of this invention land are not to be interpreted in a limiting sense. The only limitations are to be determined from the scope of the appended claims.

I claim as my invention:

1. A control system for a pair of motors comprising, in cmbination, means for supplying electrical energy to said motors, a pair of relays for reversibly connecting one of said motors to said means for supplying electrical energy, a third relay for connecting the other of said motors to said means for supplying electrical energy, a reciprocating member driven by said one motor, and operable to each of two extremes of position, a rotatable member, constructed and arranged for intermittent rotation through a predetermined angle and driven by said other motor, first and second switches having normal positions and actuated positions, each of said switches being disposed for actuation by said reciprocating member, one at each extreme of movement thereof, third and fourth switches each having two positions of operation, one a normal position and one an actuated position, means for operating said third and fourth switches so that one is in its normal position when the other is in its actuated position for each intermittent movement of said rotatable member through said predetermined angle, circuit means connecting one of said pair of relays in circuit relation with said first and third limit switches to eect energize.- tion of said one relay when said first and third switches are in normal positions, circuit means connecting the other of said pair of relays in circuit relation with said second and fourth switches to effect energization of1 said other of said pair of relays when said second and fourth switches are in normal positions, circuit means connecting said third relay in circuit relation with said first and fourth switches to effect energization thereof when said first and fourth switches are in actuated positions, and circuit means connecting said second and third switches'in circuit relation with said third relay to effect energization thereof when said second and third switches are in actuated positions.

2. A motor control system comprising, in combination, a first motor, a second motor, means for supplying electrical energy, a pair of relays for reversibly connecting said first motor to said means for supplying electrical energy, a third relay for connecting said second motor to said means for supplying electrical energy, means for limiting the rotational movements of said first motor in each of its two rotational directions including first and second switches, each having a normal position and an actuated position, means driven by said first motor for actuating said first and second switches, third and fourth switches, each having a normal position and an actuated position, means driven by said second motor for operating said third and fourth switches, constructed and arranged to position the third switch in its normal position and the fourth switch' in its actuated position during one portion of the operating cycle of said second motor and to reverse the position of the third and fourth switches during another portion of the operating cycle of said second motor, means for energizing one of said pair of relays when the rst and third switches are in normal position, means for energizing the other of said pair of relays when the second and fourth switches arein normal position, means for energizing the third relay when the iirst and fourth' switches are in actuated positions, and means for energizing the third relay when the second and third switches are in actuated positions.

3. In a control system for controlling the operation of an oscillatable member and a unidirectionally operable member, the combination of, a first motor for driving'the oscillatable member, means for supplying electrical energy to effect reversible operation of said first motor, a second motor for driving said member to be unidirectionally operated, second control means for connecting said second motor to said means for supplying electrical energy, switch' means responsive to the movements of said oscillatable member upon movement of said oscillatable member to each of its extremes of position, switch means responsive to movements of said unidirectionally operable member, and interlocking circuit means connecting said switch means responsive to movements of said oscillatable member, said switch means responsive to said unidirectionally operable member and said first and second control means for effecting alternate operation of said first and second control means.

4. In a control system for effecting alternate operation of a reversible member and a unidirectionally operated member, the combination of a rst motor for driving said reversible member, a second motor for driving the unidirectionally operated member, means for energizing said second motor when said reversible member is in one extreme of position, means for deenergizing said second motor upon predetermined movement of said unidirectionally operated member, means operable when said unidirectionally operated member is stopped and said reversible member is in said one extreme of position for energizing said rst motor to effect operation thereof to drive said reversible member to its other extreme of position, means operable when said reversible member reaches its other extreme of position for deenergizing the first motor, means operable upon movement of said reversible member to said other extreme of position for energizing said second motor, means for deenergizing said second motor upon predetermined movement of said unidirectionally operated member, means operable when said unidirectionally operated member is stopped for reversibly energizing said first member to effect operation of said reversible member in a reverse direction toward said one extreme of position, and means for deenergizing said rst motor when said reversibly operated member reaches said one extreme of position.

5. In a control system for effecting alternate operation of a reversibly operated member and a unidirectionally operated member, the combination of, means for supplying electrical energy, a first motor for driving said reversibly operated member, a second motor for driving said unidirectionally operated member, a pair of relays for reversibly connecting said first motor to said means for supplying electrical energy, a third relay for connecting said second motor to said means for supplying electrical energy, means for energizing said third relay wh'en said reversibly operated member is in one extreme of position to energize said second motor and drive said unidirectionally operated member, means for deeneriin'g said third relav upon predetermined movement of said uzl'iidirectionall37 operated member, means for energizing one of said pair of relays when said unidireotionally operated member is stopped to eiect energization of said motor to drive said reversibly operated member toward the other eXtreme of movement thereof, means for deenergizing said one of said pair of relays when said reversible member reaches said other extreme of movement thereof, means for energizing the third relay upon movement of said reversible member to said other extreme of movement thereof to effect, energization of said second motor 'and operation otk-said unidirectionally operated member, means for deenergiz'ing said third relay upon predetermined movement of the unidirectionally operated member, means for enere gizing the other of said pair of relays upon stopping of said unidirectionally operated member to eect reverse energizaton of said rst motor and operation of said reversibly operated member in the direction of said one extreme of position, and means for deenergizing said other of said pair of relays upon movement of said reversibly operated member to said one extreme of position.

JOHN E. ROBLEE.

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