US2518324A - Electronic synchronizing circuit - Google Patents

Description

250-2 1 w 252 Ex IOSS REFERENCE EXAMINER FIP8212 xR 2,518,326 i 1950 s. c. HURLEY, JR 2,518,324 ELECTRONIC SYNCHRONIZING CIRCUIT I Filed Jan. 4, 1947 2 Sheets-Sheet 1 S a Q Q 0 E E if: v m 2 g; a a

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INVEV TOR.

JAMUEL C. HURLEXJR. BY fiwudw' a MW A rro azvls'ya LANHHHL.

2 Sheets-Sheet 2 Filed Jan. 4, 1947 FIG. .2

FIG. 6

FIG. 7

IN VEN TOR. SAMUEL Cf HURLEX J12. BY fimauat & Walla-ad,

Arroam: Y:

Patented Aug. 8, 1950 ELECTRONIC SYNCHRONIZING CIRCUIT Samuel C. Hurley, Jr., Danville, 111.; Wilmina L. Hurley, executrix of said Samuel C. Hurley, Jr., deceased, assignor to Wilmina L. Hurley, Danville, Ill.

Application January 4, 1947, Serial No. 720,225

1 (Llaim.

This invention relates to an electronic synchronizing device and particularly to an electronic circuit for use in connection with such a device.

This invention is concerned with the problem of synchronizing one operation with another. It is concerned with synchronizing a plurality of successive operations as well as synchronizing successive operations one with another. It is concerned with the circuit used in such operations wherein a predetermined bias must be maintained on a control grid in .an amplifying circuit for a predetermined period corresponding to a required operation.

For example in colored printing operations, particularly with rotogravure printing presses, where the final print comprises a plurality of superimposed colors, it is necessary that any color superimposed upon another comes at the proper .place. If the colors are placed properly, the two operations are-in registration. If the colors are improperly placed, the two .operations are out of register. My device is primarily concerned with colored .printing but it ,is applicable to other operationssuch as a cutting or trimming operation which must occur in register withsome previous operation. For example, labels which are to be pasted on can goods are printed in long rolls and a cutting tool must cut between each label at .the proper place. My device 'is suitable for causing the cutter to cut in register with the previously printed material.

My device is also useful in .connection with stamping operations where it is necessary to have a plurality of successful stamping operations occur each in register with the others. My device is particularly useful in color printing where the first printing roll jbesides accomplishing the regular printing, places an indicia mark on a moving web of paper and the second printing roll must print in register with the first. photoelectric scanning device inspects an indicia mark and the photoelectric scanner in conjunction with the timing device synchronized with the second printing roll controls the registration of the second printing roll .with the first.

My device is also useful in controllingdisplay and store signs wherein the signs ,are to display one color for a certain period and then another color for another predetermined period. The circuit of my invention is also useful in many typesof machine work. For examplein grinding operations, my device can control .the startin of the grindin QIJeration and the .finish of .a grinding operation in order that only a mode- 2 termined amount of grinding would occur on the article being ground.

The same thing applies to lathes where a. cutting tool is to remove only a predetermined amount from an object such as an axle and similar objects. ;It ,could also be used for reciproeating the cutting tool in the lathe, i. e., the cutting tool begins cutting at a certain point and when the lathe moving the object along the cutting line reaches a predetermined point, the cutting tool is disengaged from the operation and is returned to its initial starting point. There are many applications of the circuit of my invention which I will describe herein.

it is therefore an object of my invention to provide an improved type of circuit to accomplish the above set forth purposes.

It is an object of my invention to provide an improved timing circuit in connection with an electronic timing switch whereby a predetermined bias is maintained on a control grid for a predetermined period corresponding to a certain mechanical operation.

It is a further object of my invention to provide an improved circuit for use in .connection with r gistration control equipment.

it is a further object of this invention to provide an improved timer which is synchronized with an element operating on a moving web and to cause the timer to cooperate with a photoelectric scanner for maintaining the Operation in register.

Another object of the invention is to provide an improved electronic ,means in connection with the timer for maintaining a certain potential on the control grid in the amplifying tube in synchrony with the speed of the printing press.

'It is also an object of my invention to provide an electronic circuit having two control grids in which one .control grid is connected to ya photoelectric scanner and the other control grid is connected to a timer means which is synchronized with an element operating on a moving strip of material.

It is still a further object of my invention to provide an electronic amplifying circuit for use in connection with my improved timer which determines the forward and rearward tolerance of the position of the element operating on a continuous moving web relative to ,a preconditionedportiqnof said web together with means respon ve to said circuit for varying the p ition of said element relative to said ,web when he preconditioned m rtion .O Isaid vweb ,is not within said of tolerance .Imcth wor 3 I have provided an improved circuit for not only determining whether the device is in register, but if it is out of register, in which direction it is out of register.

Broadly the circuit of my invention comprises amplifying means having a first control grid whereby the bias on said control grid is alternately changed by an electronic timing circuit responsive to an electronic timing switch, said switch synchronized with a predetermined operation in which the timing circuit comprises a first electronic amplifying tube and a second amplifying tube connected in parallel across a source of current, each of said last mentioned tubes having an anode circuit, a cathode circuit and a control grid, each control grid connected to the'loaded anode circuit of the other tube respectively such that the two tubes are 180 out of phase, each of said grids controlled by said timing switch such that said bias on said grids are alternately changed whereby current alternately flows through each of said tubes, said first control grid of said amplifying means being connected to the loaded anode circuit of one of said two tubes in said electronic timing circuit whereby the bias on said first control grid is alternately changed with each alternate change in the flow of current through the loaded anode circuit to which said first grid is connected.

Another and somewhat specific embodiment of my invention is a device for correlating a first mechanical operation with a second successive mechanical operation, said device comprising a timing switch responsive to said second operation, a timing electronic circuit responsive to said switch, said electronic circuit comprising a first electronic amplifying tube and a second electronic tube connected in parallel across a source of current, each of said tubes having a loaded anode circuit, a cathode circuit and a control grid, each of said control grids connected to the loaded anode circuit of the other tube respectively such that the two tubes are 180 out of phase, each of said grids controlled by said timing switch such that bias on said grids are alternately changed whereby current alternately flows through each of said tubes, an electronic amplifying circuit comprising amplifying means having a first control grid and a second control grid, said first control grid having its bias controlled by an electro-responsive device, said second control grid connected to the loaded anode circuit of one of the two tubes in said electronic timing circuit whereby the bias on said second control grid is alternately changed with each alternate change in the flow of current through a loaded anode circuit to which said second grid is connected, said alternate change of flow of current responsive to said timing switch.

More specifically my device comprises an element operating on a material, a light sensitive circuit containing a light sensitive device, said light sensitive device associated with said element and said material for detecting the occurrence of a pie-conditioned portion of said material; and an electro-responsive device having an indexing position correlated with said preconditioned portion of said material; said electroresponsive device synchronized with the movement of said element for determining the position of said element relative to its indexing position; an electronic circuit simultaneously responsive to both said light sensitive device and said electro-responsive device for determining the position of said preconditioned portion of said ma- 4 terial relative to the indexing position of said element; and means responsive solely to said electronic circuit for varying the relative positions of said element and said material when the preconditioned portion of said material is not in register with said indexing position within a predetermined tolerance.

Still more specifically my invention comprises web register mechanism for rotary printing.

presses having a first printing cylinder and a second printing cylinder for operating on a continuous moving web; a first printing cylinder simultaneously operating on said web and placing longitudinally spaced indexing means thereon; photoelectric means associated with said second printing cylinder for detecting said indexing means; a light source; means for projecting said light source onto said web at a point adjacent said second printing cylinder where said indexing means appear on said web; said photoelectric means positioned to receive said light; a first amplifying circuit; said photoelectric means arranged in said first amplifying circuit so that the output of said amplifying circuit is a positive potential pulse when light is received from a single indexing means onto said photoelectric means; a second amplifying means having a first control grid and a second control grid, said second control grid connected to said amplifying circuit such that the bias on the said second control grid is maintained negative when light is received from said web on said photoelectric means but said second control grid receiving said positive potential pulse when light is received from said single indexing means on said photoelectric means; a third amplifying means having a first control grid and a second control grid, said second control grid connected to said first amplifying circuit such that the bias on the said second amplifying grid is maintained negative when light is received from said web on said photoelectric means but said second control grid receiving said positive potential pulse when light is received from a single indexing means onto said photoelectric means; a rotating electro-responsive device having its rotation synchronized with the rotation of said second printing cylinder; said cylinder having an indexing position correlated with said indexing means on said web; said electro-responsive device having lag registration means associated therewith for indicating the rotation of said second printing cylinder toward said indexing position; said electro-responsive device having registration lead or advance means associated therewith for indicating the rotation of said second printing cylinder from said indexing position; said electro-responsive device having in-register means associated therewith for indicating the indexing position of said second printing cylinder between a rearward tolerance and a forward tolerance; means for normally maintaining a negative bias on said second control grid of said second amplifying means; means for placing a positive bias on said second control grid of said second amplifying means by said lag registration means responsive only as said second printing cylinder rotates toward said indexing position; means for maintaining a negative bias on said second control grids of said second and third amplifying means by said in-register means responsive only when said second printing cylinder is in indexing position between said rearward tolerance and said forward tolerance; means for normally maintaining a negative bias on said second control gridof. said third amplifying means ior placing a positive bias on said second control grid of said third ampliiying means by said advance registration means responsive only as said second printing cylinder rotates toward said indexing position; operative means controlled by an increase in the flow of current through said second amplifying means, responsive only to siznlutaneously placing of positive potentials on the first and second control grids, as above set forth, for increasing the speed ofv rotation of saidsecond printing cylinder when said second printing cylinder is out of register with the operation of said first printing cyLmder in a rearward direction; said operative means also controlled by an increase in current throughsaid third amplifying means responsive only to simultaneously placing of positive potentials on both the first-and second control grids of said third amplifying, means. as above set forthr for decreasing the rotation of said second printing cylinder when it is out of register with the operation of the first printing cylinder in a forward direction; and means controlled by said in-register means for maintaining said operative means neutral when said second printing cylinder is in register with the operation of said first printing cylinder. I

Other objects, advantages and uses of my invention. will become apparent by referring to the drawings in which Figure '1 shows the complete circuit together with an electronic timer switch tor use in registration control device.

Figure. 2 is a diagrammatic plan viewof a pair of printing rolls in which the first printing roll places an indicia mark on the moving strip and the second printing roll must be in register with the first. Figure 2 also shows one way of employing a. reversible motor for controlling the relative position of the second printing roll in re lation with a preconditioned portion or the strip.

Figure 3 is a schematic. side view of a portion oi Figure 2 along the lines 3-4 showing a manncr of employing a light source and a photoelectric tube tor scanning the indicia marks. Figure 4 is a graph of the potential created by the electromagnetic timer at each point as the, rotating magnet'approaches each of a. plurality of shunts.

Figure 5 illustrates amechanical timing switch rather than the magnetic timing. "switch which is shown in Figure 1.

Figures '6 and 7 show the use of a photoelectric timing swltch'which is-not equivalent, butais' used for the same purpose as the magnetic switch shown in- Figure l. and the mechanical switch shown in- Figime Figure 6 is an end View showing the location of thephctotubes: andthe slotsin the rotatable memher 34. Figure 6 is a section along, the line 6-6 r Figure '7.

Figure 7 is a side elevationof Figure. 6 iii-cross Figure 8 ilhistrates-the wiring diagram for the phctotube I28 of Figure-6 ands similar wiring circuit is employed for eachof the phototubes of 1129, I and "I of Figure 6.

1 Throughout: the specification and claim, whenever I speak of apositive or negaztivle potential; orapositi-ve ornegative bias, I mean the; relative potential or bias of. the control gridwlth-respect its cathode. The. cathode and grid may both be at a positive potential-but if the-grid is more positive than the cathode; a. positive: bias-0r potential. is placed on thexgrid. Likewise both 6 may have a positive potential but if the grid is less positive than the cathode, a relative negative potential is placed on the grid.

I will describe my invention inconnectim with the above figures relative to a registration control device for maintaining one printing cylinder in register with anothez although it is distinctly understood that my device is applicable in many fields and applicable to other types of registration control.

Referring to Figure 2,. a. plurality of indicia marks 85 are placed along the margiml edge of the printing web 28 by the printing. cylinder 84 and see Fig. 3) the phototube I0 is positioned to scan the indicia marks due to the light proiected by means of the incandescent light and the projection lens M4. Referring to Figure 3:, the phototube Ill just described in connection with Figure 3 is provided in a circuit connected across a direct current source of potential having its positive terminal at Hi5 and its negative terminal at I05 A suitable amplification system Hi1 is provided to amplify the pulse received by the phototube ML The amplification system Lil-I is also adapted and arranged that when the phototube HI sees an indicia mark, a positive potential is placed at the point It which simultaneously places a positive potential or bias on the control grids L8 and t9. Whaa the phototube I0 is scanning the lighter background of the paper, a negative potential is maintained by the amplifying system Ill-1 at the point 8| and a negative bias is maintained on the con.- trol grids l8 and IS. The amplification system I01 forms no. part of this invention.

The function of the phototube L0 in connect tion with the magnetic timer 32 will be hereinafter more fully described.

Referring again to Figure 1, amplifying tubes l2 and Id of the gas-filled arc discharge type are connected in parallel between the point i l and the ground point 15. The two tubes 12- and- 13 are connected in series with the vacuum; tube ii and the three tubes l2, l3- and I6 are connected to a source of direct current having its positive terminal at I1. The function of the tube Ii will be more fully described later herein.

The normal bias-on the control grids l8 and 1-9 is maintained negative with respect to their respectivecathode circuits 2D and 2| of.-the tubes l2. and "respectively by means. of theibins rectilfier 22-. The control grid 48 is connected from the point 23 through the resistor 24 to the neg-ative side 25 of the bias rectifier .22. The control grid L9 isconnected from the point 25 through the resistorl'l to the negative side -25- of. the bias rectifier 22. Thus when the phototube ill-receives merely a reflected light -from the relative light colored strip-or web 28 (see Fig. 2)-a negative bias is. maintained on the control grids 48 and ill-end the gaseous-filled tubes t2 and L3 are unable to ionize even though a positive. potential should be: placed on either of thescreengrids- 29 and 30-, oi the tubes tfland respectively. The screen grid '28 of the tube 12 and the screen grid; at the tube 13 are controlled by anelectro-responsive device such as the electro-timer -3t aewill be hereinafter described.

The electro-timer is generally designated as: u in Figs, l, 5,6 and '1 although ill-Fig. 1. it. com!- prises a magnetic timer-32, inFig. 2 themechamical contact timer 3d and in 'Eigsixfiand. 'I- the photoelectric timer '34.

The magnetic timer :32; iszshomnvschematicaim in. Figure L toillustrate the manner im which .11.

'magnet and the arm 31 is the south pole.

functions. The magnetic timer 32 comprises the rotatable magnet arm 35 which is magnetized such that its axis 36 is the north pole of the The magnet 35 is a permanent magnet but it is within the scope of this invention to use an electromagnet. Four shunts 38, 39, 40 and 4| are arranged around the circumference of rotation of the magnet 35 such that none of the shunts actually touch the magnetic arm 31. The shape of the magnet arm 31 and each of the shunts 33 through 4| control the shape of the potential current which is generated in each of the induction coils associated with each of the shunts. Induction coils 42, 43, 44 and 45 are respectively associated with the shunts 38, 39, 40 and 4|. Due to the shape of the magnet arm 31 and the shunts, the shape of the potential curve generated in each of the induction coils as the shunt approaches and leaves each shunt is that as shown in Figure 4. For example, as the magnet 35 is rotated and approaches the shunt 38, a positive charge is generated in the coil 42 which starts off at the ground potential marked A in Figure 4 and increases to the point B and then sharply drops to a negative potential at point C when the magnet 35 is directly opposite the shunt 38 as shown in Figure 1. As the magnet 35 continues its rotation in the direction of the arrow 46, and leaves the shunt 38, the potential increases from the negative potential at C back to ground potential at D. As the magnet 35 rotates past each shunt the shape of the potential curve is that shown for Figure 4. In my invention I make use of the potential created by the magnet 35 as it passes each shunt. The magnet 35 is attached to and synchronized with the shaft 41 about which the printing cylinder 48 rotates so that when the arm 31 f the magnet 35 is mid-way between shunts 39 and 40, the printing cylinder 48 is in the registration position for printing on the sheet 28. In other words, the shunts 39 and 40 determine the in-register position of said device within a forward tolerance and a rearward tolerance. The arm 3! indicates the position of an element such as the printing cylinder |2'| relative to a predetermined position which is indicated between shunts 39 and 4|].

I will now describe how the magnetic timer 32 functions in controlling the bias of various grids of the amplifying tubes of my circuit. Referring to Figure 1, let it be assumed that the arm 3! is at position E and is being rotated toward the shunt 38. It can be seen from Figure 4 that a positive potential is being generated in the induction coil 42 and therefore a positive potential is placed at the point 49. This places a positive potential on the control grid 50 of the amplifying tube The amplifying tube 5| has a cathode circuit 52 and a loaded anode circuit 53. The tube 5| is connected across a source of direct current potential having its positive terminal at 54 and grounded at 55. Biasing resistors 5'6, 51 and 58 are provided so that the normal bias is negative which prevents the tube 5| from conducting a current. Tube 5| does not conduct a current until a positive potential is placed on the control grid 5|) by the rotation of the magnet 35 as previously described. A load resistor 59 is connected in the anode circuit 53 of the tube 5| between the points 60 and 6|. The control grid 52 of the tube I6 is connected to the loaded anode circuit 53 at the point 5|. The vacuum tube I6 is thereby connected 180 out of phase with the tube 5|. When the bias on the control grid 50 is negative, the tube 5| conducts little or no current and therefore the potential on the control grid 62 is substantially that of the positive terminal 54 and the tube l6 conducts a current or is in condition to conduct a current providing either of the gas-filled tubes l2 and I3 are conducting a current.

It is characteristic of a gas-filled tube which is connected to a direct current source of potential that once such tubes are ionized, they will continue to ionize or conduct a current until a circuit is broken. That is, once they are ionized, the control grids have lost control for preventing the flow of current no matter how negative the control grids are driven. Therefore the magnet 35, the tube 5| and the tube l6 provide a means for deionizing the tubes I2 and |3 between each inspection of an indicia mark II in order to place the circuit in condition for the inspection of the succeedin mark. As the magnet 35 approaches the shunt 38, it places a positive potential on the control grid 50 which increases the flow of current through the tube 5| and places a negative potential on the control grid 62 which stops the flow of current through tube l6 and therefore deionizes or prevents the tubes l2 and I3 from ionizing. As the magnet 35 rotates in a clock-wise direction as indicated by the arrow 46 and comes directly opposite shunt 38 as shown in Figure 1, the potential at 49 sharply drops from a positive potential of B in Figure 4 to the negative potential of point C. When the point 49 receives such a negative potential, it places a similar negative potential on the control grid 50 which substantially stops the flow of current through tube 5| and places a positive potential on the control grid 62 of the tube l6, and the gas-filled tubes l2 and |3 are in a position to conduct a current provided a sufi'icient positive bias has been placed on the control grids and screen grids of either of the tubes l2 and |3. In other words, when the magnet 35 is opposite shunt 38, the gas-filled tubes I2 and I3 are in effect directly connected to the positive terminal l1 and are ready to ionize if other conditions permit as will be hereinafter set forth. The magnetic timer also controls the bias on each of the screen grids 29 and 30 of the tubes 2 and I3 respectively. However for my device to function I must provide means for maintaining a certain predetermined potential on the screen grids 29 and 30 during a certain portion of the rotation of the magnet 35. This is accomplished by the following circuit.

The screen grid 29 is controlled by the magnet 35 through a pair of amplifying tubes 63 and 64 which are connected in parallel across a source of direct current potential having its positive terminal at 65 and its negative terminal at 68. A load resistor 6! is connected in the anode circuit of the tube 93 between the points 68 and 69. A similar load resistor 10 is connected in the anode circuit tube 64 between the point 1| and the point 12. The tube 63 has a control grid I3 and tube 54 has a, control grid 14. It should be noted that each of the control grids l3 and 14 are connected to the loaded anode circuit of the other tube. That is, the control grid 13 is connected from point 15 through the resistor 16 to the point 12 and the control grid I4 is connected from the point 11 through the resistor '18 to the point 69. By such an arrangement an increase in current through one of the tubes 63 and 64 automatically causes a decrease in the flow of current through the other tube. While the two tubes 53 and 34 are shown in separate envelopes, it is understood that circuit including anode 39, grid 13 and its respective cathode, and the grid I4 with its respective anode and cathode can all be included in one envelope and will function the same as if in separate tubes as actually illustrated.

Assuming again that the magnet 35 is at the point E and is approaching the shunt 38, a positive potential is placed at the point 49 which places a positive potential on the control grid I3, and the tube 63 is conducting a current. When the tube 63 conducts a current, the point 59 is driven in a negative direction which places a negative potential on the control grid 14 and prevents the tube 84 from conducting any substantial amount of current. When the tube 64 is not conducting, the point 12 is substantially that of the positive terminal 65 and a positive potential is placed on the control grid 13. However when the magnet 35 reaches the position shown in Figure l, the potential sharply drops from a high positive value B to a low negative value C as illustrated in Figure 4 and this places a negative charge of potential at point 49 which drives the bias on the control grid 13 in a negative direction substantially stopping the flow of current through tube 63. When the flow of current is stopped through the tube 63, a positive potential is placed on the control grid 14 of the tube 63 which is substantially equal to that of the positive terminal point 65 and the tube 64 conducts a current which drives point 12 in a negative direction and maintains a negative potential on the control grid 13. Thus as long as the tube 64 conducts a current, it is impossible for the tube 63 to conduct a current. This is the condition that exists during the entire time that the magnet 35 passes from directly opposite shunt 38 to directly opposite shunt 39. During the rotation of the magnet between the shunts 38 and 39 the tube '63 does not conduct a current and a positive potential is maintained at point 69 which maintains a positive potential on the screen grid 29. It has been heretofore described that also during this time a positive potential exists on the control grid 62 of tube IS. Therefore if simultaneously a positive potential is placed on the control grid in of the tube l2, current will flow from the positive terminal I! through the tube l6 through the tube 12 to the ground l5.

It has also been explained heretofore that when the phototube 10 receives the light from the incandescent light source 80 of Figure 3 as reflected from the indicia mark II, that a positive potential is placed on the point 8| which places a positive potential on the control grid l8. Therefore if at any time during the rotation of the magnet between the shunts 38 and 39 the phototube should see the indicia mark II, the tube I! will conduct a current which will energize the relay coil 82 and close the relay switch 83.

I have described before that the magnet 35 is synchronized with the printing cylinder 48 such that when the magnet 35 is between the shunts 39 and 43, the printing cylinder is in position for printing on the sheet vMl. Therefore if the magnet 35 is between shunts 39 and 40 at the same time, phototube Ii! sees the indicia mark H, the printing cylinder 43 is in register with the printing cylinder 84 (see Fig. 2). The printing cylinder -84 imprints the first printing on the web 28 thereby preconditioning the web for a subsequent operation and at the same time places on the web along one margin thereof a series of indicia marks 35. when one of the indioia marks 85 reaches the point of inspection by tube 10, I have indicated it by the reference numeral ii. Further referring to Figure 2 I have illustrated schematically a type of printing operation comprising a pair of printing cylinders 84 and 19 in which the first printing roll M preconditions the web 28 with a certain impression and the second printing cylinder 48 must place a second impression upon the web 28 in register with the impression placed thereon by the printing cylinder 81. There are many means for driving such a pointing press. There are many ways for placing on the indicia mark '85. I have illustrated longitudinal registration although my device as shown in Figure 1 would apply email-y well to lateral registration. mdicia marks, like the marks 35, are not the only way of obtaining registration. Cuts, notches or holes could be used as the indicla means and the tube 13 could be placed on the side of the web 28 opposite light source 88. Also in lateral registration the phototube 13 can inspect lines or edges of a. sheet for the purpose of obtaining registration. In other words the schematic illustration of Figure 2 is only illustrative of one type of registration of an operation in which the registration thereof can be controlled by my invention which is illustrated in Figure 1.

In Figure 2 a common drive shaft 36 is provided to which the shaft #1 with the printing cylinder 48 is attached by means of the gearing means 81. The shaft 83 of the printing cylinder 34 is attached to the shaft 86 by means of the gearing mechanism 89. A speed "control device 90 is attached to the shaft 41 between the printing cylinder 48 and the gearing mechanism 81. This is shown schematically since such speed controls are well known for accomplishing the pui-pose as set forth herein. The speed control 90 is connected by the shaft 9| to the reversible motor 92. When the reversible motor 92 is turned in one direction it urges the device '99 so that as to increase the speed of the printing cylinder 48 and when the reversible motor 9! is changed in the opposite direction, the speed of the printing cylinder '48 is reduced by the device 93.

I have previously described the manner in which the tube 12 conducts a current when the phototube l8 sees a mark at l I when the magnet 35 is at any point between a shunt 38 and 39. When this condition occurs, the printing cylinder 48 is out of register with the cylinder 34. If it is out of register in the direction that the mark ll indicates that the web 28 is ready to receive a certain imprint from the cylinder 49, but the cylinder is not yet in position to print such an impression, it is out of register in the rearward direction which means that the speed of the cylinder 48 must be'increased in order to bring the device back into register. Therefore when the tube II conducts a current it actuates the relay switch 83 to the closed position shown in Figure 2 which causes the reversible motor 92 to rotate in one direction thereby adjusting the speed regulating device 30 to increase the speed of the printing roll 48 to bring the device back into register. Therefore as long as the mark 1 l appears so to speak between the chants 38 and 39 the speed of the cylinder l8 will increase until the device is back into register which is the condition when the mark H appears between the shunts 39 and 40. It should be noted that if the mark I0 appears between the shunts 38 and 39 and nearer to the shunt 38, a greater arfiustment would ocout than it the mark appears between the shunts hl\l llllll lb 38 and 39 closer to the shunt 39. I therefore have provided a means such that the more the device is out of register, the greater the adjustment. It is also apparent that the position of the shunts 39 and 40 determine the tolerance. If the two shunts are close together, a close tolerance on registration is obtained. If the shunts 39 and 40 are far apart, a relatively wide tolerance is obtained. The position of the shunts 38 to 4| determine the limits at which the adjustment will be made to bring the device into register.

While in Figure 1 I have illustrated only four shunts for one complete cycle of operation, a plurality of similar four shunts may be provided around the circumference of the rotation of the magnet 35 according to the number of times that the indicia mark l appears at the point indicated in Figure 2 for each rotation of the printing cylinder 49. Another way to accomplish this same object is to have only the four shunts shown in Figure l but have a speed reducer associated with the shaft 41 and the magnetic timer 32 so that the magnet 35 rotates several times faster than the shaft 41 and the amount of gearing depends upon the number of times that the indicia mark appears for each revolution of the printing cylinder 49. It is obvious that if close registration control is desired, that the mark II appear a relatively large number of times for each revolution of the printing cylinder 48 in order to maintain the device in register at all times by a number of small corrections thereby eliminating a large correction at any one time. That is to say. a number of small corrections for the registration is preferable over a few large corrections. It should be understood that while I have described a rotating timer 32, that a sliding ma net ||6 could be used and this would be particularly useful in lateral registration control and/or in many other types of re istration control. In all cases a timer such as 32 is provided which synchronizes the operating point of an element operating on a material with the point at which re i tration is desired to be obtain d.

When the arm 35 of the magnetic switch 32 passes by the shunt 39. a negative potential is placed on the control grid 14, a os tive potential is placed on the control grid 13 and a negative potential is placed on the screen grid 29 of the tube l2. Therefore if the mark so to spe k appears between the shunts 39 and An at the same time, the arm 31 appears between said shunts. the device is in register and a negative potential is placed on the screen grid 29 which prevents the tube I2 from conducting a current, the relay switch 83 is not actuated and no change in the s eed of the printing cylinder 48 results. Thus when the device is in re ister. the tube I2 does not conduct a current. Therefore the tube l2 conducts a current and its relay switch 83 is actuated only when the device is out of register in a rearward direction.

Thus shunts 38 and 39 provide a lag registration control means for indiaction that the device is out of register in a rearward direction and said shunts also indicate the relative position of said printing roll 48 with a predetermined position, said predetermined position being the point indicated when the arm 31 is between shunts 39 and 49. Shunts 38 and 39 also provide a means for indicating the approach of the operation of the printing cylinder towards its in-register position. Likewise shunts 39 and 40 provide a means for indicating the iii-register position of the printing cylinder and shunts 40 and 4| provide a means for indicating when said device is out of register and also indicates when the printing cylinder passes its indicia point or predetermined position both of which are indicated when the arm 31 is between the shunts 39 and 40.

In a similar manner the bias on the screen grid 30 of the tube I3 is controlled by the tubes 92 and 93. The tubes are connected in parallel across a direct current source of potential having its positive terminal at 94 and its negative terminal at 95. Load resistors 96 and 91 are provided for the same purpose as the corresponding load resistors 61 and I9. Control grid 98 is provided in tube 92 and control grid 99 is provided in tube 93. The two tubes 92 and 93 are arranged in identical manner as the tubes 63 and 64 such that when one of the tubes conduct a current it is impossible for the other to conduct any substantial amount of current. The screen grid 30 is connected to the point I09 in the anode circuit of the tube 92. When the magnet 35 is rotating from the shunt 39 toward the shunt 40, a positive potential is placed on the control grid 98 which means that the tube 92 is conducting a current and tube 93 is not conducting and the point I is driven in a negative direction due to the load resistor 96 and a negative potential is maintaned on the screen grid 30 which prevents tube I3 from conducting a current. Under this condition the relay coil |Il| is not energized and the relay switch I92 is not actuated and the deviec is in register. Thus when the device is in register, it is impossible for either of the tubes I2 or |3 to conduct current due to the maintenance of a negative potential on the screen grids 29 and 30. However immediately upon the arm 31 leaving the shunt 40, a negative potential is placed on the control grid 98 which renders the tube 92 substantially non-conducting and tube 93 conducts. When this occurs, point I09 is relatively positive and screen grid 30 is relatively positive. If at any time during the rotation of the arm 3'1 between the shunts 40 and. 4! the mark II is seen by the phototube III, a positive potential is placed on the control grid I9 of tube I3 simultaneously with the positive potential placed on the screen grid 39 and the tube I3 conducts a current which closes the relay I02 to reverse the motor 92 in the opposite direction thereby actuating the speed controller 90 and decreases the speed of the printing roll 48. In other words when the mark so to speak appears between the shunts 40 and 4| the device is out of register in the forward direction and the speed of the printing roll 48 must be reduced. Thereby the arrangement of the tubes 92 and 93 provides a means for maintaining a negative potential on the control grid 98 for the period during which the arm 3'! is rotating between the shunts 40 and 4| or the printing cylinder 48 is rotating past its predetermined or registration position between the shunts 39 and 49. During this time a, positive potential is maintained on the control grid 99 which maintains the tube 92 in non-conducting condition and thereby maintains a positive bias on the screen grid 39 so that if a indicia mark appears at this time, the tube l3 will conduct due to the fact that a positive potential has been placed simultaneously on the screen grid 30 and the control grid l9. As the magnet 35 leaves the shunt 4| it places a negative potential on the control grid 62 of tube l6 and if either of the tubes l2 or I3 have been ionized during the cycle just described, it will be deionized and the cycle is ready to begin again Referring again to Figure 2, the sheet 28 is passed by feeding means (not shown) to the cylinders 84 and 48 in the direction indicated by the arrow I03. Suitable feeding rolls and tension rolls are of course required for feeding the web during the printing operation but this forms no part of my invention.

Referring to Figure 5, the mechanical timer 33 difiers from the magnetic timer 32 of Figure 1 only in the specific manner of impressing a certain bias on certain of the control grids. The mechanical timer 33 comprises an arm I08 having an axis I09 which is synchronized with the axis 41 of Figure 2 in the same manner that the axis 36 of Figure 1 is synchronized with the axis 41 of Figure 2. A typical electrical contact brush H is attached to the arm I08 which brushes the contact points III, H2, H3, H4 and H5. The axis I09 is connected to the point H6 to which is connected the negative side of a suitable battery II1. Thus the brush I I0 in contacting the various points III to H6 inclusive places a negative bias at the points H8, H9, I and I2I in exactly the same manner as the magnetic switch 3 2 of Figure 1 places a negative bias at the points II8, H9, I20 and I2I when the arm 35 becomes directly opposite the shunts 38, 39, 40 and M respectively. In other words the contact points H2, H3, H4 and H5 correspond exactly in function to the combined function of the shunts 38 to M inclusive and the induction coils 42 to 45 inclusive. A negative bias is placed on the control grid 62 of the tube I6 of Figure 1 in between inspection of the indicia marks by the brush I I0 contacting the point III due to the fact that a negative potential is placed at the point I22 in Figure 5 which corresponds to the point I22 of Figure 1. In case a mechanical switch in Figure 5 is used, the amplifying tube 5| need not be used, and the control grid 62 is connected directly to the contact point I I I. Thus during each revolution of the arm I08 the tube I6 does not conduct a current which places the tubes I2 and I3 in condition for the next inspection of an indicia mark 85.

Referring to Figures 6 and 7, a photoelectric timer I123 is provided which functions in identical manner as the mechanical timer 33 of Figure 5, and the magnetic timer 32 of Figure 1. A solid disk I24 is provided having an axis I25 which is synchronized with the axis 41 of the printing cylinder 48. The solid disk I24 has an opening I26 for permitting light to pass from the incandescent light I21 onto one of the phototubes I28, I29, I30 and I3I. A suitable shield I32 having projections I33 is provided which allows the phototubes I28 and I3I only to receive. light when the opening I26 comes at the proper place between the phototubes and incandescent light I21. All of the phototubes are connected in the same circuit and by way of example the circuit for the phototube I28 is shown in Figure 8. The phototube in Figure 8 is connected in series with the resistor I34 across a direct current source of potential having a positive terminal at I35 and a negative terminal at I36. A suitable amplification system is provided such that when the phototube I28 or any of the other phototubes receive light from the incandescent light source I21 through the opening I 26, the amplification system I31 places a negative potential at the point II8. Similarly when phototube I29 receives light, a negative potential is placed at II9, when phototube I30 receives light, a negative potential is placed at point I20 and when the phototube I3I receives light, a negative potential is placed at the point I2I. The points II8 to I2I inclusive of Figure 6 correspond to the same points II8 to I2I inclusive of Figure 1. Thus the arrangement of the phototubes I28 to I3I about a circumference corresponding to the circumference of the rotation of the slot I26 together with the circuit of Figure 8 serves the same function as the combined function of the shunts 38 to 4| and induction coils 42 to 45 respectively of Figure 1. Likewise when the phototube I 28 secs light, a negative potential is placed at the point I22 which corresponds to the same point I22 of Figure 1 which places a negative bias on the control grid 62 for the same purpose as heretofore described for Figure 1.

The above description is merely illustrative of my invention and it is understood that other modifications may be made within the scope of my invention.

I claim as my invention:

A device responsive to the position of a moving mechanical element synchronized with a moving web at the occurrence of an electrical signal and discriminating the occurrence of said signal in at least one period of said movement from its occurrence in other periods of said movement comprising a main amplifier and an auxiliary amplifier with two stable modes of operation, said electrical signal being responsive to a predetermined position of said web relative to said mechanical element, an electroswitch synchronized with the movement of said element for determining the position of said element relative to the predetermined position of said web, said switch imparting impulses to said auxiliary amplifier dependent on said relative position such that a predetermined impulse changes said auxiliary amplifier into one mode of operation and at least one other predetermined impulse changing said auxiliary amplifier into the other mode of operation, said electrical signal being fed to said main amplifier through one channel and said auxiliary amplifier being connected to said main amplifier through another channel whereby the output of said main amplifier is controlled jointly by said electrical signal and by the modes of operation of said auxiliary amplifier.

- SAMUEL C. HURLEY, JR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,844,950 Finch Feb. 16, 1932 2,230,715 Cockrell Feb. 4, 1941 2,250,209 Shoults et a1. July 22, 1941 2,285,463 Ridgway June 9, 1942 2,306,361 Stuart, Jr. Dec. 22, 1942 2,348,862 Sorkin May 16, 1944

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