US2609197A - Register control system - Google Patents

Description

Sept-2, 1952 H. F. MoKENNr-:Y ET AL REGISTER CONTROL SYSTEM Filed Nov. 18, 1949 INVENTORS Henry E NcHe/{ney /Zl les/re4 ra/M ATTORNEY ILLE ffl? L...-

Patented Sept. 2, 1952 REGISTER CONTROL SYSTEM Henry F. McKenney, Flushing, and George A. Lieske, Brooklyn, N. Y., assignors to The Sperry Corporation, a corporation of Delaware Application November 18, 1949, Serial No. 128,216

3 Claims.

This invention relates to registry control systems and more particularly to a system for controlling the registration of the printing cylinders of a multicolor printing press.

An object of the invention is to provide a photoelectric registry control system which responds only to predetermined register marks on the running web. Another object is to provide a system of the above type with means to prevent actuation of the control mechanism in response to marks or printing on the web outside of a predetermined area containing the register mark.

Various other objects and advantages will be apparent as the nature of the invention is more fully disclosed.

In one embodiment of the invention the position of the printing cylinder is determined by scanning photoelectrically a member rotating with the cylinder and having a slit or other designation at its periphery and comparing the timing of the cylinder signal with a web signal obtained by scanning the register marks on the web. In order to prevent spurious actuation of the correction motor the slit or designation on the cylinder chamber is made suilciently wide to produce a signal which persists over a period corresponding to the maximum error to be corrected and electrical gate means is. provided to render the control effective only during such periods.

More specifically the cylinder member may comprise a disc rotating with the cylinder and having a slot of substantial angular extent through which a beam of light is passed from one or more light sources onto a pair of photoelectric tubes arranged to receive the beam in sequence as the disc rotates, with a slight overlap during which both tubes are energized. The signal obtained from the two tubes in sequence is converted into a wide ilat topped wave which is used as a gate signal to condition the control tubes for actuation. One of the photoelectric tubes also produces a signal which constitutes the cylinder signal. A third photoelectric tube scans the web and produces the web signal. The relative timing of the cylinder and web signais and the coincidence of the gate signal are utilized to actuate the correction motor. In this way the correction motor does not respond to a false web signal derived from printing or the like at times when no gate signal is produced.

The novel features of this invention will be better understood from the following description, taken in connection with the accompanying drawings in which a specific embodiment has been set forth for purposes of illustration,

In the drawings:

Fig. 1 is a schematic diagram of a registry control circuit embodying the present invention; and

Fig. 2 is a detail view of the cylinder disc.

Referring to the drawing more in detail, a printed web I is shown as fed by feed rolls I8 to a printing cylinder I I which is driven by suitable means such as a drive shaft I6 connected through a gear ybox containing a diierential and a register control motor I1 as set forth in detail in application Serial No. 100,890, filed June 23, 1949, for Intaglio Printing Press. The web I0 carries an index mark I2 which may comprise a mark printed by a previous printing cylinder of the press. A disc I3 having a peripheral slot I4 is shown for convenience as mounted on the shaft I5 of the cylinder Il. The disc may. however, be geared to the cylinder or a drum driven with the cylinder may be used.

Light rays from a source are directed by lenses 2I and 22 in two separate beams 23 and 24 through the slot I4 onto photoelectric tubes 25 and 26, respectively.

The photoelectric tube is provided with an anode connected to an anode supply line 3l and with a cathode 32 connected through a resistor 33 to a D. C. source 34. The cathode 32 is connected to a grid 35 of a cathode follower tube 36 having an anode 31 connected to the line 3l and having a cathode 38 connected to ground through a resistor 39. The cathode 38 is connected through a blocking condenser 40 to the grid 4I of an amplifier tube 42 having a cathode 43 connected to ground through a resistor 44.

y The grid 4I is'ground'ed through a resistor 45.

The photoelectric tube 25 is provided with an anode 50 connected to the line 3l and with a cathode 5I connected through a resistor 52 to a D. C. source 53. The cathode 5I is connected to the grid 54 of a cathode follower tube 55 having an anode 56 connected to the line 3i and a cathode 51 grounded through a resistor 58.

The cathode 51 is connected by a line B0 through a blocking condenser 6I to the grid 62 of an amplier tube 63V having a cathode 64 grounded through a resistor 65. The grid 62 is grounded through a resistor 66.

The anodes 10 and 1I of the tubes 42 and 63 are connected together through a resistor 83 to the line 3l and through a condenser 84 to the grid 12 of an inverter tube 13 having an anode 14 connected through a resistor 15 to the line 3l and by a line 16 to the grid 11 of a cathode follower tube 18 having an anode 19 connected to a suitable D. C. source and a cathode 8l 3 grounded through a resistor 92. The cathode 8| is connected by a lead 85 to control grids 83 and 8l of pentodes 88 and 89, respectively.

The lead 5G from the cathode of the tube 55 is also connected through a condenser 95 to the grid 9S of a, tube 91 having an anode 98 connected through a resistor 99 to a D. C. lead |99, and by a lead to a second grid |02 of the pentode 88. A tube |03 has an anode |94 connected through a resistor |95 to the lead |39 and by a lead |05 to a second grid |01 of the pentode 89. The tubes 91 and |93 are connected as an Eccles Jordan circuit in which the tubes are alternately made conducting and nonconducting in accordance with the signal applied to the grid 9G. For this purpose the cathodes of the tubes 9i and |03 are connected together and grounded through a resistor |38, their plates and grids are cross-connected through resistors H9 and and their grids are grounded through resistors H2 and H3, respectively.

The web signal is derived by a beam of light from a source which is reflected from the web I3 onto a photo-electric tube I2 l. The light beam is focused on the area traversed by the register mark I2 by lens |22 and the reflected light is focused on the tube |2| by a lens |23. The photoelectric tube |2| has an anode connected to a D. C. supply line |24 and a cathode |21 connected through a resistor |25 to a D. C. source |25. The cathode |27 is connected to grid |23 of a cathode follower tube |29 having an anode connected to the line |24 and a cathode grounded through a resistor ||9 having a variable tap |39. The tap |33 is connected by a lead |3| to third grids |32 and |33 of pentodes 88 and 89, respectively. Cathodes |35 and |36 of pentodes S8 and S9 are connected to the D. C. line |99.

Anodes |38 and |39 of the pentodes 2B and 89 are connected by leads |40 and lili to a pulse converter |42 having output leads |43 and |411 connected to control the operation of the register motor The pulse converter |22 is arranged to apply a D. C. control voltage to the lines m3 and |64 the polarity and value of which is-de pendent upon the amount and direction of unbalance between the space currents through the respective pentodes 88 and 89.

In the operation of this system the photoelectric tubes 26 and 25 are pulsed in sequence by light beams 24 and 23 as the slot Ui in the disc I3 is brought into registration with the light beams during the rotation of the disc. The slot |11 is so designed that the tube 25 is pulsed just before the tube 26 is deenergized so that the combined pulses are continuous for the duration of the gating period. The pulse on the tube 23, through the cathode follower tube produces a positive pulse on the lead and on the grids 92 and 93 of tubes 53 and 91, respectively, which renders these tubes conductive for the duration of the pulse. In a similar manner the tube i2 is made conductive for the duration of the light pulse on the photoelectric tube 25. Due to the anode resistor 83 a negative pulse is produced on the anodes lil and 1| and applied to the grid T2 of the tube i3 for the duration of the two light pulses. This negative pulse may have a sharp peak at the instant of overlap of the two light pulses but this peak is eliminated by the tube i3 which is adjusted to be blocked during the entire period of the negative pulse on its grid. Through the tube 'i8 the negative pulse on the grid 'I2 is converted to a positive pulse on the grids 86 and 8'! which extends over the combined period of the pulses on the photoelectric tubes 26 and 25 and 4 permits the pentodes 88 and 89 to operate when the proper signals are applied to their other grids. When no positive gate signal is applied to the grids and 81 the grids are maintained sufficiently negative to block the pentodes and thus prevent operation thereof except during the gate period.

The tube 9'.' is normally nonconducting and the tube |93 conducting when no signal is received from the photoelectric tube 26. With the tube Si? nonconducting a positive voltage is applied to the grid |92 of the pentode 83 from the self biased anode 98 of the tube 91. With the tube |03 conducting a negative voltage is applied to the grid lill of the pentode 89. Pulsing of the photoelectric tube 25 applies a positive pulse to the grid Se which renders the tube 9i conducting and the tube |93 nonconducting, thereby placing a negative pulse on the grid |92 and a positive pulse on the grid |01 for the duration of the pulse on the photoelectric tube 25. Thus the pentode 89 is conditioned for conducting during the period of the light pulse on the tube 25 and the pentode 88 is cenditioned to conduct at other times during the gating period, but neither pentode can conduct outside of the gating period due to the cuto by the grids 86 and 8l.

'The web signal, through the photoelectric tube 22| and tube |29, produces a positive pulse on the gri-:ls 32 and |33 of the pentodes 88 and 89. ff his will render conducting the pentode which is conditioned at that instant by 'positive voltages on both of its other grids. If the web signal coincides with the pulsing of the photoelectric cell 26 the pentode 39 is rendered conductive and if it occurs during the gating period but outside of the period of pulsing of the tube 25, that is during the pulsing of the tube 25, the pentode 88 becomes conductive. The operation of the respective pentodes thus indicates a lead or a lag in web position and a correcting signal is sent over the lines ist and Idil to the registry control motor As stated above the tube 25 is preferably pulsed just before the tubev26 isdeenergized, and Fig. 2 represents the relative position of the disc |3 at this instant o'f overlap. It will be understood. however, that the overlap is merely a safety factor so as to assure an absence of gap in the gating period. In correct registry the web signal period is equally divided by the cut-off of the pulsing of tube v23 and the control is responsive to the differential of the web signalen the two sides of that cut-off.

lf the web signal occurs at any time outside of the gating period the pentodes remain blocked and no response is Yproduced in the motor V|'|. Hence any marl: ordesignation on the web between the positions reserved, for the registry mark will not produce an undesired operation of the correction motor and the entire area of the web, except for a limited area around each registry mark, can be usedfor the usual printing.

The system has been described Afor convenience as applied to a multicolor printing press. It may however be applied to other uses, such as to the registry control of cutting knives or perforating knives in a web cutting or perforat'ing machine. 'Various embodiments will be apparent to aperson skilled in the art.

What is claimed is:

l. In a control Vsystem for a machine 'having an element operating upon a moving web of material in predetermined relationship with respect to register markings'thereon, 4means for driving said web and said element at predetermined speeds, a registry control mechanism including a correction motor connected to adjust the relative driven positions of said web and said element, photoelectric scanning means scanning said web and having means producing a web pulse corresponding to the passage of each of said register markings, a pair of other photoelectric scanning means, a member driven with said element and having a gating area arranged to pulse said other photoelectric scanning means in continuous sequence and in predetermined relationship with the position of said element, a circuit connected to produce a gating signal in response to and of a duration corresponding to the sequence of pulses on said other scanning means, a circuit connected to produce a pulse in response to the individual pulse of one of said other scanning means, and a control circuit having means responsive tothe coincidence of said web pulse, said gating pulse and said individual pulse to operate said correction motor in one direction, and having means responsive to the coincidence of said Web pulse, said gate pulse, and the absence of said individual pulse to operate said correction mo-tor in the other direction.

2. In a control system for a machine having an element operating upon a moving web of material in predetermined relationship with respect to register markings thereon, means for driving said web and said element at predetermined speeds, a registry control mechanism including a correction motor connected to adjust the relative driven positions of said web and said element, photoelectric scanning means scanning said web and having means producing a web pulse corresponding to the passage of each of said register markings, a pair of other photoelectric scanning means, a member driven with said element and having a gating area arranged to pulse said other photoelectric scanning means in continuous sequence and in predetermined relationship with the position of said element, a control circuit to actuate said correction motor including a pair of pentodes, connections applying a positive pulse to one control grid of each pentode in response to said web pulse, connections applying a positive pulse to a second grid of one pentode and a negative pulse to a second control grid of the other pentode in response to a pulse on one of said pair of other scanning means and reversing the pulses on said second control grid on cessation of said last pulse, and connections applying a positive pulse to third control grids of both of said pentodes in response to a pulse'on either of said other scanning means, whereby one or the other of said pentodes becomes conductive in response to coincidence of the Web pulse with one or the other of the pulses of said other scanning means and both pentodes remain nonconductive in the absence of a pulse on one or the other of said other scanning means, and a circuit responsive to the selective actuation of said pentodes to actuate said correction motor in a direction to maintain a predetermined relationship between said web pulse and said other pulses.

3. In a control system for a machine having an element operating upon a moving web of material in predetermined relationship with respect to register markings thereon, means for driving said web and said element at predetermined speeds, a registry control mechanism including a correction motor connected to adjust the relative driven positions of said web and said element, photoelectric scanning means scanning said web and having means producing a web pulse corresponding to the passage of each of said register markings, a pair of other photoelectric scanning means, a member driven with said element and having a gating area arranged to pulse said other photoelectric scanning means in continuous sequence and in predetermined relationship with the position of said element, circuit means including two pentode electronic tubes and adapted when the tubes are conductive to reversibly energize the correction motor, means normally positively biasing one grid of one tube and negatively biasing the corresponding grid of the other tube, means responsive to the pulsing of one of the said pair of other scanning means for reversing the bias on said grids, means normally negatively biasing aY second grid in each tube, means responsive to the gate pulsing of said pair of other scanning means for reversing the bias on said second grids, means normally negatively biasing the third grid of each tube, and means responsive to a web pulse for reversing the bias on said third grids, whereby the coincidence of the web pulse with the pulsing of one of said pair of other scanning means renders one pentode conductive and the coincidence of the web pulse with the pulsing of the other of said pair of scanning means renders the other pentode conductive and the control of the correction mctor is responsive to the difference in the time that the period of the web pulse is coincident with the respective periods of pulsing of the scanning means of the said pair.

' HENRY F. MCKENNEY.

GrEOitGrEv A. LIESKE.

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

UNITED STATES PATENTS Number Name Date 2,250,209 Shoults et al July 22, 1941 2,348,862 Sorkin May 16, 1944 2,396,706 Kott Mar. 19, 1946

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