US2050315A - Photoelectric paper cutting control - Google Patents

Description

Aug. 1;,JQ36. F. H. G'ULLIKSEN PHOTOELECTRIC PAPER CUTTING CONTROL Filed Feb. '1, 1932 2 Sheets-Sheet 2 INVENTOR Him H GulZZ/isen.

WITNESSES:

IATTCSRNEY Patented Aug. 11, 1936 UNITED- STATES PATENT OFFICE PHOTOELECTRIC PAPER CUTTING CONTROL Application February 1, 1932, Serial No. 590,267

1 Claim.

This invention relates to electrical control systems for apparatus operating on material.

More specifically, this invention relates to electrical control systems, involving thermionic means and light sensitive means, for controlling the relative positions and relative speeds of certain parts of a machine operating on a web.

In the art of paper cutting or printing, the operation on the paper or web of material, when moving from a supply reel past certain rolls to the cutter, nearly always involves slippage, thus the paper becomes shifted relative to the cutter or other machine. Even when there be no slippage, the hygroscopic characteristics of paper, or temperature or both, cause a change in its dimension with changes of relative humidity and/or changes in temperature with the result that the cutter will not cut the paper along the desired line. Slippage and the moisture effect may, of course, occur simultaneously and tend to compensate or to cumulate.

It is an object of this invention to control the operation of apparatus operating on a web so that the required operation on the web will take place at the right point regardless of the slippage of the web or the change of dimension of the web or both.

Another object of this invention is to control the relative speeds of a cutter and the feeding means of a machine operating on a web by photoelectric control means. I

A further object of this invention is to control the position of the web in a machine operating on a web by photo-e1ectric control means.

Another object of this invention is to control the relative speeds of certain parts of a machine operating on a web and the relative position of these parts by the cooperative action of photoelectric and thermionic means.

Other objects and advantages will become apparent from a study of the following specification when considered in conjunction with the accompanying drawings, in which:

Figure 1 is a diagrammatic showing of the cutter, web-feeding device and driving means therefor; and I Fig. 2 is a diagrammatic showing of part of the control system for controlling the operation of some of the equipment shown in Fig. 1.

Referring more particularly to Fig. 1 of the drawings, I26 designates an induction motor, or. any other electric motor, supplied with electrical energy from the buses'20l, 202 and 203 through the line contactor I29. A cutter 29 is coupled to the motor I26 through the reduction gear I3I.

The motor I26 is also utilized to drivethe web feeding mechanism or roll 28, the operation of the web feeding mechanism taking place through a mechanical differential, or localizer, and a speed changer both of which may be adjusted by a pair 5 of motors I01 and I03, respectively. The web feeding mechanism 28 is coupled to a shaft I33 through suitable reduction gearing.

Associated with the apparatus for operating on the web is alight sensitive device I! and a 10 source of light 21 mounted in the housing 221 provided with the slit 228.

Some of the control equipment appears on Fig.

1 but the main part of the control equipment is shown in Fig. 2 and consists of a plurality of 15 amplifier tubes I8, I9 and 24 and a'pair of hot cathode tubes 22 and 23.

The theory of operation of the scheme, generally stated, embodies the synchronizing of a spot I, printed on the paper, with the operation of some contact members 30, 3| and 32 designed to rotate with the cutter when the cut is right on the spot or at some predetermined distance from the spot. When the spot is synchronized the brushes on the contact members do not engage the contact segments thereof when the photocell impulse from the cell I1 is obtained. If however, the spot I is not in proper position with ref erence to the cutter 29, the impulse given to the photo-cell H by the increase of current flowing 30 therein modifies the operation of amplifier tube I9 and this modified operation, because of the fact that the contact segments coupled to the cutter are not in synchronism with the spot on the paper or web, causes the hot cathode tube 23 or 22, as the case may be, to break down thereby operating either relay I or relay 2. When one of these relays has operated, one of the contactors 34 or 35 may be operated to establish a circuit for the motors I01 and I03 (see Fig. 1).

Operation of the motor I01 causes a shift in position between the cutter 29 and the web feeding roll 28, whereas the operation of motor I03 causes a change in the speed difference between the cutter and the web feeding roll 28. Since, as here broadly indicated, both motors I01 and I I03 are caused to operate, the change in speed relation between the cutter and the web feeding mechanism is in the direction to make the correction necessary to perfectly synchronize this spot on the web and the knife of the cutter. The operation of the motor I01, operating on the housing I22 of the differential mechanism, causes a shift in position between the cutter and the web feeding roll 28 in such a direction as to correct for the amount of asynchronous operation between the cutter blade and the spot on the web. After the motor I01 or I03 has operated for a short interval of time determined by a timing circuit arrangement described more in detail hereinafter, the correction necessary may have been completed and no further synchronizing operation is necessary. v

An important factor in any cutter control application is the mechanical arrangement of the feed-roll, speed-changing device, and the localizer equipment. In. some cutting applications, the slip of the paper is relatively small or substantially zero or practically constant so that when the speed ratio between cutter and the feed roll is once adjusted, the entire control can be obtained by means of the localizer adjustment, namely, the positioning of the housing I22 of the difierential mechanism.

In other applications, the slip varies considerably from time to time due to changing air moisture and air temperature and a speed ratio change as well as a localizing change is required in order to get satisfactory operation. It is, therefore, obvious that for some applications, the motor I03 may be required to operate whenever the spot I on the web and the cutter 29 are not synchronized and the motor I01 operating the mechanical localizer equipment is also required to operate at the same time. However, when such combined operation is not necessary, switches 204 and 205 may be selectively operated so that either motor I03 or motor I01 or both may be caused to operate when the spot on the web is not in synchronism with the knife of the cutter.

A better understanding of the invention may be had from a study of the sequence of operation involving a typical synchronizing operation for the spot on the web and the cutter. In the specific embodiment herein disclosed, reference characters 5|, 52 and 53 designate the bus bars of a 60-cycle, three-phase, 440-volt source of alternating current and reference characters 4| and 44 represent the buses of a single-phase, 60- cycle, l10-volt circuit. It is to be understood, however, that the specific frequencies mentioned or voltages of the sources of supply are not part of this invention and merely disclose one application of this invention.

Assuming manually operated controller segments 43, 45, 46 and 41 are moved to bridge the contact fingers shown in connection with the controller segments, a plurality of circuits are thereby established. The transformer 36 is energized from conductors 4| and 42 and transformer 38 and the light 21 are also energized from the conductors 4| and 42. The transformer 38 has a double-wave rectifier 25 connected in the secondary windings 40 thereof and conductors 13 and 14 are connected to the direct-current junctions of the rectifier 25. To provide for the requisite sensitivity of photo-cell I1, the condensers 15 and 11 and the reactor 16, resistor sections 18 and H2 and resistor III are interconnected with the photo-cell I1 by conductors 19 and 80. The photo-cell I1 is so positioned with reference to the source of light 21 that the light coming from source 21 passes through the slot 228 and through the material onto the sensitive elements of the photo-cell. The resistance value of the resistor III as well as the potentiometer circuit involving resistors I I2 and 18 increase the sensitivity of the photo-cell I1 so that a slight variation in the amount of light transmitted through the web will materially increase the current flowing in' been properly heated. To prevent premature the photo-cell circuit. Any change in the amount of current flowing in the photo-cell I1 will, by the conductor 80, increase the negative bias on the grid of the amplifier tube I9 and thus materially decrease the current flowing through 5 tube I9.

The transformer 36 is provided with a plurality I of secondaries 26, 2|, 20 and 31; the secondary 26 energizes the filament of amplifier tube I8 through conductors 10 and 1|; the secondary 2| o energizes the filament of the amplifier tube I9 through conductors 68 and 69; the secondary 20 energizes the filament of the hot cathode tube 23 through conductors 63, 65, 66 and 61 and also energizes the filament of the hot cathode tube 22 5 through conductors 63, 65, I53 and I54; and the secondary 31 energizes the filament of the amplifier tube 24 through conductors 6|, 62 and 56. It should be noted that the secondary 20 of the transformer 36 is provided with a tap at its mid- 20 point and a conductor 64 leading to the resistor I3.' When there is a predetermined change in the current flowing through resistors 9 and I0, either hot cathode tube 22 or hot cathode tube 23 will be caused to break down in a manner 25 more specifically pointed out hereinafter.

A double-wave rectifier 48 is interconnected with the buses 5|, 52 and 53 by the controller segments 45, 46 and 41 thereby supplying the conductors 49 and 50 with a direct current potential. 30 Assuming conductors 49 and 50 are energized,

a circuit is established from conductor 50 through resistor I5, resistor I3 in parallel circuit relation filament of tube 24 and the resistor sections I3 and I5 occurs at substantially the same instant.

it is desirable that no operation of the hot cathode tubes can take place before the filaments have operation of any of the control equipment, the condenser 59 and the resistor 58 are interconnected with the resistor sections I5, I3 and 60 and the grid of the tube 24 in such a manner that a negative bias is placed on the tube 24 for a substantially predetermined interval of time and no current can, therefore, flow from the conductor 55 to the conductor 56 prior to the expiration of such predetermined interval of time.

After the lapse of the predetermined interval of time mentioned, the eifect of the resistor 58 and the condenser 59 becomes negligible and an operating circuit for the relay 4 is established from the energized conductor 50 through the actuating coil of the relay 4 through conductor 55 55, the plate and filament of the amplifier tube 24, conductor 56, resistors I3- and 60 connected in parallel circuit relation and conductor 51 to the energized conductor 49.

For the complete operation of this system, it 60 must, of course, be assumed that the switch I21 has been closed to energize the actuating coil I 28 of the line contactor I29 thereby energizing the motor I26 from the conductors 20I, 202 and 203. Operation of the motor I26 drives the cut- 65 ter 29 and the contact members 30, 3| and 32 through the reduction gear- I3I and this motor also drives the web feeding roll 28 through shaft I23, bevel gears I24 and I25 of the mechanical localizer 225, the speed-changing device 226 and 70 the shaft I33 to the feeding roll 28 by means of the reduction gearing shown. The material I32 is fed from a supply reel I34.and passes over the idling and tension adjusting rollers I35 and I" of the feeding roll 28 with which it is made to err--7 gage by the spring actuated idler roll I31. As will be observed, any movement of the cam I08 will operate the spring biased levers H1 and H8 pivoted at H5 and H8 in such a direction that the cone-shaped two-part pulleys H3 and H4 will change the speed of the roll 28 relative to the speed of the cutter 29. As long as the housing I 22 remains fixed, the relative position of the feed roll 28 and the cutter 29 remains fixed and for any given position of the cam I08, the relative speeds of the cutter and feeding device remains constant. It is obvious that the paper or other web material after having been threaded through the machine may not be in proper position, that is, the line on which the paper is to be cut may not.

be at the desired position. To efiect the proper positioning of the knife of the cutter with reference to the web, switch 205 is closed and controller C is operated in one or the other direction to bridge the contact fingers shown therewith, depending on the direction -in'which it is desired to move the cutter with reference to the web. After the cutter has been properly positioned, the controller C is again positioned as shown and switches 205 and 204 are closed, if both a speed changing adjustment and a localizer adjustment is desired during the normal operation of the paper cutter. If but one of the adjustments is desired, either switch 205 or switch 204 is closed depending upon which adjustment is desired. More often, both switches 204 and 205 are closed because, due to the hygroscopic characteristics of paper, the slippage may change from time to time and the rate of change may vary so that not only a change in the speed relation between the cutter 29 and the web feeding roll 28 is necessary but also a repositioning of the cutter 29 with reference to the web and, in consequence, roll 28 is necessary.

The web is provided with indicia on the edge thereof consisting of a black or apaque mark I about a quarter of an inch in width and one-half of an inch in depth, just sufficient to periodically cut ofi a large percentage of the light falling on the photo-cell I1 from the source of light 21. The specific dimensions of the printed mark are not material to this invention. It is suflicient that some indicia be placed on the web at the points it is desired the web is to be cut or at some predetermined position with reference to the desired cut so that the amount of light transmitted from the source of light to the photo-cell is periodically modified.

If the apparatus is in, normal operation and the adjustment of the web with reference to the cutter as well as the speed of the cutter with reference to the web feeding device 28 has been properly adjusted and that, due to slippage or the change in dimensions of the web due to its hygroscopic character or due to the changes in temperature surrounding the web, the indicia I are not in the desired position with reference to the cutter, the contact segments 3I or 32 will be in such a position that motors I03 and I01 may be caused to operate.

Each time the printed mark I passes between the source of light 21 and the photo-cell I1, the amount of curent passing through the photo-cell is materially decreased and the grid voltage of the amplifier tube I9 is changed so that the current flowing from the plate of the tube I 9 to the cathode is increased, the current passing from the energized conductor 50 through conductor 8|, the plate and filament of the tube I9, conductor 82, contact ring 30 (see Fig. 1), contact segment 3|,

conductor 83 to the junction G, resistor I0 and conductor 85 to the energized conductor 49. The change in current through resistor I0 changes the bias on the grid of tube 23, because 'the grid of the hot cathode tube is connected to the junction G through the resistor 84.

The change of the bias on the hot cathode tube 23 causes this tube to break. down and a circuit is thereby established from the energized conductor 50 through conductor 86, contact members 81 of the relay 4 (now closed), contact members 88 of the relay 3, resistor 33, contact mem-- bers 89 of the relay I, actuating coil 90 of the control relay 2, the hot cathode tube 23, conductors B6 and 61 through the secondary winding 20 of the transformer 36, conductor 84 to a portion of a resistor I3 and conductor 51 to the energized conductor 49. Operation of the control relay 2 causes the opening of the contact members I5I thereby preventing the operation of the control relay I even though the hot cathode tube 22 may forsome cause break down. A circuit is also established from the energized conductor 42 through conductor 9|, contact members 92 of relay 2, conductor 93, the actuating coil of the line contactor 35 and conductor 95 to the energized conductor 4|. Operation of the line contactor 35 establishes a circuit between the buses 96 and I05 leading to a suitable source of direct current power, the circuit being through the conductors 91, 98 and 99, contact members I00 of the relay 35, conductor IOI, series field windings I 02 and I09 and the respective armatures of the motors I03 and I01, switches 204 and 205 and conductor 304 to the energized conductor I 05.

'Themotors I03 and I01 will, therefore, operate to change the speed relation between the web feeding roll 28 and the cutter 29 and also the relative position of the cutter with reference to the feed roll 28.

Since the plate voltage of the tube 23 is supplied from a source of direct current power, the tube will remain broken down even after the grid of the tube is again made negative due to a decrease in the plate current of the tube I9. The operation of the motors I03 and I81 will, therefore, continue until stopped by some other means.

It will be noted that the operation of the control relay 2 also closed the contact members I43 thereby establishing a circuit from the energized conductor 50 through the resistors I4, and I4 and I6 connected in parallel circuit relation, conductors I40 and I42, contact members I43 of relay 2, conductors I44, I45 and 85 to the energized conductor 49. The current flowing through they resistor I6 and the resistor sections I 4' and I4 changes the potential of the grid of the amplifier tube I8 so that the current from the plate to the filament of tube I8 is materially increased. However, to prevent the immediate change in current through the tube I8, the potentiometer circuit, shown at the resistors I4 and I6, is utilized and interconnected with the condenser 6 and the resistor 5 by the conductor 12. After the lapse of a substantially predetermined interval of time, the current inthe amplifier-tube I8 will increase by an amount suflicient to operate the control relay 3. The circuit for the control relay 3 may be traced from the energized conductor 50, the actuating coil of the control relay 3, conductor I 39, the plate and filament of the amplifier tube I8, conductor 1I, resistor I4 and I6, conductors I40 and I42, contact members I43 of the relay 2, and conductors I44, I45 and 85 to the energized conductor 49. Since the control relay 3 is sum-- ciently energized to operate, contact members 88 are moved to open circuit position thereby deenergizing the actuating coil of the control relay 2. When the control relay 2 is deenergized, the circuit for the line contactor 35 is interrupted and the motors I03 and I01 are caused to stop. Since the contact members I43 are also open, the bias on the grid of the tube I8 is also removed and control relay 3 is deenergized and contact members 88 are again closed. Since the contact members 88, I5I and 89 are again in circuit closing positions whereas the contact members 81 remain in circuit closing position, the sequence of operation may be repeated if and when the indicia I have become displaced with reference to the cutter.

For the preceding discussion it was assumed the indicia were displaced in a given direction with reference to the cutter, say behind the cutter. If the opaque mark be ahead of the cutter, the sequence of operation is much like that heretofore discussed except that the contact segment 32 is now brought in cooperative relation with the brush connected to the conductor I55 just when the impulse from the photo-cell I1 is received. Such being the case, a circuit is established from the energized conductor 50 through conductor 8|, the plate and filament of the amplifier tube I9, conductor 82, contact ring 30, contact segment 32, conductor I55, and resistor 9 to the energized conductor 49. The change in current in resistor 9 changes the bias on the grid of tube 22, when the circuit is completed through the contact ring 30 and the contact segment 32. To prevent excessive current through the grid of the hot cathode tube 22, resistor I56 is interconnected with the grid and the conductor I55.

The change of bias on the grid of the hot cathode tube 22 causes the operation of the control relay I. The circuitfor control relay I may be traced from the energized conductor 50 through conductor 86, contact members 81 and operation of Lthe control relay 2. Closing of the contact members I58 establishes a circuit from the energized conductor 42 through conductors 9| and I51, contact members I58 of the relay I, conductor I59, the actuating coil of the line contactor 34 and conductor to the energized conductor M. The line contactor 34 connects the motors I03 and I01 for reverse operation to the source of supply 96 and I05. The circuits for the motors may be traced from the energized conductor 98 through conductors 91 and 98, contact members I60 of the contactor 34, conductors I6I and I62, series field .windings I63 and I64 and the armatures of the respective motors I01 and I03, switches 205 and 204 and conductor 304 to the energized conductor I05. Since the series field windings I63 and I64 are energized, the localizer equipment 225 as well as the speed changing device 226 are both operated to such a position that the indicia I is properly positioned with reference.

to the cutter 29.

Closing of the contact members 243 of the relay I completes the circuit through the resistors I4, I4 and I6 thereby efiecting the operation of the amplifier tube I8 in a manner similar to that heretofore discussed. It is, therefore, obvious that motors I03 and I01 will operate for a short interval of time making the necessary corrections and are then deenergized by the controlling action of the amplifier tube I8.

Attention is called to the fact that the localizer equipment 225 has the housing of the difierential rigidly connected to the worm wheel I2I which is operated by the worm I20 driven by the shaft I I9 coupled to the motor I01. This sort of an arrangement provides an irreversible mechanism and holds the housing I22 in fixedposition during normal operation of the paper cutter. The condensers II and I2 interconnect with the resistor sections 1, 8, 9 and I0 and are for the purpose of controlling the time constants of the hot cathode tubes 22 and 23, respectively.

It is, of course, understood that the control equipment as shown does not necessitate a source of light so disposed with reference to the photocell that the amount of light received by the photo-cell is controlled by the amount of light transmitted through the material. Obviously, the photo-cell may be so positioned with reference to the feeding roll 28 or the idling and tension adjusting rollers I35 and I36 that light falling on these rollers may be reflected on to the photo-cell I1. Any modification of the amount of light reflected due to indicia placed on the web will effoot the same kind of a control as that herein described.

Furthermore, instead of positioning the photocell I1 as shown in Fig. 1, the light and photocell may be so pcsitioned that a screen actuated by an idler roll moving with varying positions of the slack loop in the material will cause the operation of the control equipment.

While the invention shown in the accompanying drawings and described in the foregoing specification represents one specific embodiment thereof, it is readily appreciated that the circuit arrangement and the control equipment utilized therewith may be modified to still fall within the spirit and scope of this invention. It is to be understood that this invention is only to be limited by the interpretation of the appended claim, as required by the prior art.

I claim as my invention:

' In a tubing machine for making tubular sections of equal length from elongated sheets of paper previously printed with marks at definite places, power driven draw rolls to pull the web through said machine, a power driven rotary cutter for severing the web into equal sections, an individually adjustable, variable speed transmission to vary the set speed of said draw rolls with respect to the speed of said rotary means to compensate for slippage of said draw rolls with respect to said web, a pilot motor for changing the setting of said variable speed transmission,

two circuits for controlling said motor, a rotatable 6 switch alternately closing said circuits, a photo tum for controlling the amount of current flowing through said circuits and a source of light co-operating with said marks on said web for controlling said motor by said photo tube.

FINN H. GUILIKSEN.

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