US3355973A

US3355973A - Automatic size pre-set and automatic length adjustment system for cut-off machines and the like

Info

Publication number: US3355973A
Application number: US446455A
Authority: US
Inventors: Sidney P Rubinstein; Star Harry
Original assignee: Cutler Hammer Inc
Current assignee: Cutler Hammer Inc
Priority date: 1965-03-10
Filing date: 1965-03-10
Publication date: 1967-12-05
Anticipated expiration: 1984-12-05

Description

Dec. 5, 1967 5, F. RLJEBlNSSTEIN ETAL 3,355,973

AUTOMATIC SIZE FEE-SET AND AUTOMATIC LENGTH ADJUSTMENT SYSTEM FOR CUT-OFF MACHINES-AND THE LIKE Original Filed March 26, 1962 3 Sheets-Sheet 1 CORRUGHTOZZ SL'TTEZ KAI/FE Dz/VE 45 3 4'5 I5 f 49 MH/A/ GEHR RHT/o DRIVE VQRHBLE CONTRaL SPEED Mo-raa M07012 TQflNSMISS/ON 60 INCEEME/VT HDJUSTMENT SYSTEM INVENTOR. Ah /R727 STAT/2 s/p/vsy P. Rua/NsTE/N f7... 4. BY

Dec. 5, 1967 S. F. RUBINSTEIN ETAL AUTOMATIC SIZE PRE-SET AND AUTOMATIC LENGTH ADJUSTMENT SYSTEM FOR CUT-OFF MACHINES AND THE LIKE Original Filed March 26, 1962 3 Sheets-Sheet 2 72 S 98 7o; g

FIND 2 ONE 9 O 9 SHOT GHTE 7/ M.\/, 97 R95 /o/ 91 109 was? u5 g TR 5. N. I85 I05 7'00 2, UN; 4 LONG 110 l2! gl/s lra VHEIHSLE r e I0 S-LZZTS ONE I22 5M a] MM /'/6 H7 (5, R. C. M. K a lNC/QEME/VT \/4O 2(4 SIZE F- FlDL/USTME/VT g MEE/JNS "I f 5 L ll'e INVENTORS HFTRQX 57'F-772 SIDNEY P. RUB/NSTE/N Zia/W2 (My ATTORNEY 1957 s. P. RUBINSTEIN EITAL 3 AUTOMATIC SIZE FEE-SET AND AUTOMATIC LENGTH ADJUSTMENT SYSTEM FOR CUT-OFF MACHINES AND THE LIKE 3 Sheets-Sheet 5 Original Filed March 26, 1962 6 c x 1 I I I 1 1i N M u L 0 M 6 O & W5 M U L 0 P m 6 m if 5 m C/o w 5 os wwM M J m L o c jlllflla .1 a 5 9 I 00 0 926 S %E V 7 o 5 a I T 000 o N 3 7 u w k mm 060 E s NH O E L R n o T D 7'00 SHORT lNC-QEQSE United States Patent 3,355,973 AUTOMATIC SIZE PRE-SET AND AUTOMATIC LENGTH ADJUSTMENT SYSTEM FOR CUT- OFF MACHINES AND THE LIKE Sidney P. Rubinstein and Harry Star, Franklin Park, N.J.,

assignors, by direct and mesne assignments, to Cutler- Hammer, Inc., Milwaukee, Wis., a corporation of Delaware Continuation of application Ser. No. 182,458, Mar. 26, i 1962. This application Mar. 10, 1965, Ser. No. 446,455

11 Claims. (Cl. 83-76) This is a continuation of prior copending application Ser. No. 182,458, filed Mar. 26, 1962, now abandoned.

This invention relates to an automatic size pre-set and length adjustment system and in particular to a control system for use in connection with machines or systems in which a desired number of units of equal length are cut from a leading end of a continuous moving web, tube, or the like.

While this invention may be used as control means to automatically adjust the size of cut in many different types of devices made for many diiterent purposes, it is illustrated in this specification in connection with a cutoff machine such as the one described in US. Letters Patent No. 2,059,412 granted to George W. Swift, Jr., but being equipped with an increment size adjustment means such as that disclosed in our copending application Ser. No. 448,224, filed Mar. 9, 1965 and now Patent No. 3,324,751, issued June 13,1967, a continuation of Ser. No. 67,792, filed Nov. 7, 1960, and now abandoned.

The machine of the Swift patent may be used for cutting up a web of advancing material into blanks or units of selected length. In the manufacture of corrugated paper board and fibre board, for example, such a cutofi machine is used at the delivery end of the machine or corrugator which makes the paper board. The paper board leaves the corrugator as a web. The cutoff machine receives the traveling web and cuts it into blanks of a predetermined desired length.

The Swift patent type of machine has rotary type cutters through which the web travels. The speed of the drive mechanism for the rollers on which the cutters or knives are mounted relative to the speed of the web advance .drive determines the length of the cut unit or blank.

The change of relation of the speed of the main drive for the web and the rotation of the knife rollers to vary the length of the blank is controlled by a variable speed transmission. Any suitable type of variable speed transmission may be used. An example of such a transmission is the reeves or variable speed cone drive which is disclosed in British Patent No. 412,127. The British patent also shows a cutoff machine similar to the one shown in the aforesaid US. patent except that it has provision for receiving and feeding longitudinal portions of a split traveling web into two or more pairs of revolving cutters so that two or more cutting and length adjusting operations may be carried on at the same time.

The usual type of cutoff machine in popular use has two sets of cutters, each with its own variable speed transmission adjusting control means. This type of machinery is well known in the prior art and is illustrated by the partly schematic and partly flow chart view in FIG. 1 of the drawings.

The box labeled CORRUGATOR in FIG. 1 represents the usual type of corrugating machinery. A length of cardboard leaves the corrugator as a continuous strip or web. The web may be as wide as the width capacity of the corrugator; let us say, for example, that it is seventytwo inches wide. The web 10 is then fed horizontally past a vertically disposed knife or cutting means depicted by a box labeled SLIITER. The slitter or slitting knife may 3,355,973 Patented Dec. 5, 1967 be adjusted along the width of the cardboard web to provide for two longitudinal strips of cardboard of complementary widths adding up to the seventy-two inches of the width of the original web. For example, the slitting means may be adjusted so that one strip of cardboard will be twenty-four inches wide and the other strip will be forty-eight inches wide. These two webs which are identified as 10a and 1% are then fed over rollers R into the Swift patent cutolf machine 11 and are cut into units or blanks 12a and 12b, respectively.

One strip of cardboard such as 10a is cut by the top knife 13 into blanks 12a and the other strip or web such as 10b is cut by the bottom knife 14 into blanks 12b. By setting up the corrugator and the cutoff machine 11 in this manner, cardboard blanks 12a and 12b may be made of various sizes. For example, web 10a twenty-four inches wide may be cut into blanks sixty inches long. The resulting sheet 12a would then be twenty-four inches wide by sixty inches long. The other web 10b forty-eight inches Wide could be cut into sheets forty-eight inches long. The resulting sheet would, therefore, be forty-eight inches long by forty-eight inches wide. These sizes are given merely by way of example. The machinery can be adjusted for any size blanks within the capacity of the corrugator and the cutolf machine.

The blank length adjustment is made as explained in either the United States or British patent mentioned hereinabove by means of a variable speed transmission. The variable speed transmission which may be of any suitable type is designated by a box with initials VST and by re ference numeral 15b for the bottom knife 14. The variable speed transmissions 15a and 15b are adjusted for increasing or decreasing the length of the cut piece by a gear ratio controlling motor designated by reference numeral 16a for variable speed transmission 15a and 16b for variable speed transmission 15b.

Thus, the speed of drive for knife roller 17 on which top knife 13 is mounted is controlled through variable speed transmission 15a and gear ratio control motor 16a and the speed of the drive for rotary roller 18 on which bottom knife 14 is mounted is in turn controlled by variable speed transmission 15b and gear ratio control motor 16b. The operations of the variable speed transmissions and control motors are fully described in the above-mentioned US. Patent No. 2,059,412, and are otherwise well known in the art.

Briefly, rotation of a gear ratio control motor such as 16a or 16b in one direction will result in increasing the unit or blank length of blank 12a or 12b and reversing rotation of gear ratio control motor 15a or 15b will result in decreasing the respective blank length. This will be explained more fully hereinbelow.

The procedure for adjusting each knife 13 or 14 of cutoff machine 11 in the prior art requires the operator to set the initial speeds or ratios for the variable speed transmissions 15a and 15b for the desired length of blanks 12a and 12b and then start running the web of cardboard through the cutoff machine 11. The blanks 12a and 12b would then be measured manually. If they were not the exact size desired, the operator would. then start and stop the reversible adjustment control motor 15a or 15b until, by bit or miss methods, a sheet of the proper size was cut. For example, if it was desired to have a sheet such as sheet 12a (48 inches wide and 60 inches long), the first cutoff machine would be set by the operator for a 60 inch length. Due to the nature of the machine, the initial setting is usually off within limits of approximately one inch.

If the blank was 59 inches long, the operator would have to guess how long to run the adjustment control motor in the proper direction to lengthen the blank exactly one inch. The second try might produce a blank 61 inches long; the third try, 59 /2 inches long; and perhaps by the fourth or fifth try, a blank of the desired length of 60 inches would be produced. In the meantime, since the adjustment is made as the cutoff machine is running, ten or twenty or more blanks of valuable cardboard would have been wasted in the effort as well as the time of the operator and the cost and wear and tear of running the machine.

In the aforementioned cop-ending application, a method and means for increment-size adjustment is described by providing a device to run the reversible gear ratio control motor 15a or 1511 for a pre-calculated and predetermined interval of time to provide for an exact increment increase or decrease in the cut blank to take the guesswork out of the adjustment procedure. We shall call this means the predetermined increment adjustment system. For example, the said increment adjustment system, when activated, will change the length of a cut blank by an increment of plus or minus one-tenth of an inch as desired. The increment adjustment system runs the control motors 15a or 15b as selected by means of the timing circuit of that invention for a proper interval of time to make one-tenth of an inch change. If the blanks are running 0.5 inch too long, the operator taps a decrease length switch five times to reduce the length of the blank by five separate steps of 0.1 inch. The resulting blank will then be the proper length.

However, while this increment adjustment system has many advantages, it is nevertheless necessary for an operator to keep measuring the blanks and activate the increment adjustment systems switches manually.

It is, therefore, an object of this invention to provide an automatic means for pre-setting a linear cutoff machine or the like to cut a web into units of desired length by providing means to pre-set the gear ratios of the variable speed transmissions to a known ratio for a known length by means of an electrically operated and controlled size selection system and it is a further object of this invention to provide that such an electrically operated size selection system be automatic.

It is a further object of this invention to provide an automatic length adjustment system which will call for an increased length or a decreased length adjustment in a cutoff device.

It is also an object of the invention to provide such automatic adjustment systems in forms which can be used as additions to existing machine installations as well as components of original equipment.

These objects as well as advantages are achieved by means of the invention described in this specification and illustrated in the accompanying drawings in which:

FIG. 1 is a partial schematic and partial flow sheet showing the prior art device which is employed by our invention;

FIG. 2 is a .partial block diagram, partial schematic and partial wiring diagram showing components of the automatic size pre-set system as connected to the variable speed transmission and the gear ratio control motor of the device;

FIG. 3 is a wiring diagram of the automatic size pre-set system;

FIG. 4 is a blockdiagram of the automatic size pre-set system;

FIG. 5 is an isometric view showing a detail comprising the web to be cut and the magnetic pick-up transducer and associated parts of the automatic length adjustment system;

FIG. 6 is a block diagram of the automatic length adjustment system; and

FIG. 7 is a graphic chart which shows the effect of the action of the various components of the automatic length adjustment system.

Similar numerals refer to similar parts throughout the several views.

Automatic size pre-set system The function of the automatic size pre-set or size selection system is to automatically pre-set or adjust a cutting knife to cut a length of material from a continuous web at proper cutting intervals so that the first as well as the following blanks to be cut will be of the predetermined length. Such a system is particularly applicable to the control of an arrangement such as a Swift patent cutoff machine where a knife cuts portions of a moving web and where the knife cutting rate can be varied in relationship to the web moving speed. Since the size of the blank depends on the ratio of the frequency of the knife cut to the speed of the web, if we can assume the speed of the web to be constant, varying the frequency of the knife cut with relation to the speed of the web will produce larger or smaller blanks, inversely. Thus, when the knife cut interval is speeded up, the blanks will be shorter in length and when the knife cut interval is slowed down, the blanks will be longer in length. By changing the input-output ratio of the variable speed transmission 15, the knife drive frequency changes and with a constant web speed a variation in cutoff length as achieved.

There will be a definite relationship ratio between a particular knife drive frequency and a corresponding cutoff length of material cut at that frequency and if the variable speed transmission can be preset to such known ratio, then a known cutoff length of material can be predi'cted and achieved.

The heart of the system is a polarized relay called a decision relay 30 shown in FIGS. 3 and 4. The decision relay is one in which a neutral state exists when little or no current passes through its coil such as the relay disclosed in US. Letters Patent No. 2,443,784. The relay has switching means associated with it which provides for closing one switch such as switch 31 when a current flows in one direction through coil 30 and for closing another switch such as the contacts of switch 32 when current flows through the coil 30 in the opposite direction. Contacts of switches 31 and 32 remain normally open unless closed by means of a current flow through coil 30 as just described. Closing the contacts of switch 31 will cause a current to flow through relay coil 33 which in turn is associated with contacts of switch 34. Contacts of switch 34 are in normally open position and are closed only during the time when sufiicient current flows through relay coil 33.

When a current flows through coil 30 in a direction to close contacts 32, then a current will flow through relay coil 35 which is associated with switch contacts 36 to close contacts 36 in a like manner.

Closing switch 34 will cause a current to flow through a control means which will start the gear 'ratio control motor 16 to run in a direction which will increase the gear ratio of the output to the input of variable speed transmission 15. This will serve to decrease the length of a resulting blank so we will call contacts 34 the decrease length switch of the automatic size selection system. Closing contacts of switch 36 will cause the gear ratio control motor 16 to run in the opposite direction to decrease the ratio of the output to the input of the variable speed transmission and thus to increase the length of the resulting blank. We shall, therefore, call these contacts 36 the increase length switch. It is to be understood that the operation of decrease length switch 34 and increase length Switch 36 and the construction of components between these switch contacts and the control of the gear ratio control motor 16 may be accomplished in any manner known to the art and is not specifically shown herein other than to show reference points 40 and 41 as coming from gear ratio control motor 16, and as being the points of connection.

Associated with the decision relay are a set potentiometer 42 and a follow potentiometer 43 whose

resistance elements

44 and 45, respectively, are connected in parallel by means of conductors 46 and 47. Wiper arm 48 of the set potentiometer 42 is connected to one end of decision relay coil 30 and wiper arm 49 of follow potentiometer 43 is connected to the other end of decision relay coil 30. A supply of direct current is connected to this bridge arrangement or means through a conductor 50 and normally open activating switch 51 and by means of a conductor 52 to conductor 46. Conductor 47 is grounded at point 55 to the other side 56 of the direct current supply 57.

The follow potentiometer 43 is mounted on a bracket (not shown) on the main frame of the variable speed transmission or other suitable place on the main frame of the machine. Its wiper arm 49 is rotated through a suitable gear system or means presenting it to the shaft 60 which connects the gear control motor 16 and the variable speed transmission 15. The gear means which are shown in FIG. 2 of the drawings may comprise a worm gear 61 on shaft 60 meshed to a large gear 62 which rotates a shaft 63 to which wiper arm 49 is connected. Thus, when shaft 60 rotates in one direction, wiper arm 49 may be moved in a clockwise direction as shown in FIG. 2 of the drawings, and when shaft 60 is rotated in a reverse direction to the first mentioned direction of rotation, wiper arm 49 will move in a counterclockwise rotation. It will be seen that the resistance of potentiometer 43 will be varied within the limits of rotation of shaft 60 and as the gear ratio between the output and input of the variable speed transmission is changed, wiper arm 49 will move. Therefore, wiper arm 49 is fixed on shaft 63 so that it will contact one end of resistance 45 when the gear ratio of the variable speed transmission 15 is adjusted at its highest limit and will then move to the other end of resistance 45 as the gear ratio of the variable speed transmission is adjusted by means of gear ratio control motor 16 to its lowest ratio limit.

Thus, for every particular variation of gear ratio, there will be a particular position which wiper arm 49 will take with respect to contacting resistance 45 of potentiometer 43.

The set potentiometer 42 is controlled by knob 65 which is connected to wiper arm 48 so that wiper arm 48 will rotate with it. On a suitable panel 66 calibration indicia 67 may be inscribed with relation to a pointer 68 of knob 65. If, for example, the size of the blanks cut by the machine can vary between to 200 inches, the calibration 67 can start with the figure 10 at one end and end with the figure 200 at the other end, and have the various intermediate sizes, let us say, in increments of 5 or 10 inches, in between. This would be a matter of choice.

The automatic size selection system as described takes equilibrium in its bridge means including the decision relay coil 30 and potentiometers 42 and 43. Let us assume that the value of the

resistances

44 and 45 in potentiometers 42 and 43 are exactly equivalent. If

wiper arms

48 and 49

contact resistances

44 and 45, each at dead center, the system will be at equilibrium and no current could flow through coil 30. However, if wiper arm 48 should be moved in either direction, up or down, this system of equilibrium will be disturbed and a current will flow through coil 30 with direction depending on whether arm 48 has been moved up or down. This will cause switch contact 31 or switch contact 32 to close as the case may be and cause gear ratio control motor 16 to rotate in either a gear ratio increasing direction or a gear ratio decreasing direction which in turn will cause shaft 60 to rotate in such respective direction and will result in the rota tion of wiper arm 49 of follow potentiometer 45. This rotation will continue until wiper arm 49 reaches a position against resistance 45 which will again place the bridge means in equilibrium and cause cessation of flow of current in coil 30. When current stops flowing in coil 30, Switch contact means 31 or 32, as the case may be, will again open and gear ratio control motor 16 will stop running. Thus, for each position that wiper arm 48 may be placed with respect to its potentiometer 42, there is a corresponding position for wiper arm 49 to take with respect to its potentiometer 43 and by this means and system, setting knob 65 to different positions will cause the gear ratio control motor to change the gear ratio of the variable speed transmission to different corresponding ratios and cause the arm of the follow potentiometer to follow the arm 48 of the set potentiometer.

In practice, the set potentiometer is set to a previously calibrated index number and then the activate switch 51 is closed. If this results in an unbalance in the system, the system will seek equilibrium as set forth above and the gear ratio control motor will change the variable speed transmission to the ratio called for by the set potentiometer. When this equilibrium in the system is reached, the activate switch 51 may be released.

Automatic length adjustment control system The automatic size selection system of the invention described hereinabove will be used to pre-set the equip ment for cutting a blank of a desired size. It sometimes happens during the running of the machinery, for one reason or another, that blanks of increased or decreased length will come through and there is, therefore, a constant need for inspection and re-setting the length of the cut. The purpose of the automatic length adjustment control system of the invention shown in FIG. 6 is to automatically adjust the length of the individually cut blanks time at which the knife cuts the material to the time at which the pre-set desired length of cut is supposed to be achieved. The desired length is set into counting means such as a counter 70. Counter 70 is a type of predetermined counter which will produce an output signal and reset itself, when the number of input pulses equals the number pre-set on its dials 71 such as the one obtainable commercially and known as Erie Pacific Model 300T Preset Counter. Such a predetermined counter is well known in the art and it is not necessary to describe its particular operation herein.

Input pulses to the counter 70 are generated by a magnetic pickup transducer 72 in proximity to an iron gear 73 which is mounted on a shaft 74 between two friction drive wheels 75. The drive wheels 75 and shaft 74 are mounted on the main frame of the machine in contacting relationship with moving web 10. Drive Wheels 75 are exactly twelve inches in circumference and iron gear 73 has exactly one hundred twenty teeth 76 spaced at regular equidistant intervals around its circumference. This relationship will produce one hundred twenty pulses per linear foot of travel of

web

10 or 10 pulses per inch. If preset counter 70 is set to 600, the counter will generate an output pulse when 600 input pulses have been received from the magnetic pickup transducer 72.

The magnetic pickup transducer 72 which is used in the device is well known in the art. For example, such a transducer is marketed commercially as Electro-Products Co. Model 3010-A.

Thus, a measurement of sixty inches of web is made since 600 input pulses from transducer 72 will be equivalent to the travel of 600/10 of an inch of the web 10 or sixty inches. In like manner, if the dial 71 of the counter 70 is set for 720 pulses, a measurement of seventy-two inches of web is made. It will be thus seen that a measurement of Web to any length Within the capacity of the counter 70 may be made by this part of the system comprising the length transducer 72 and the predetermined counter 70.

The knife transducer means comprises a magnetic pickup 80 which generates an electrical impulse for each revolution of the knife roller 17. This is accomplished by means of a tooth 81 which may be set anywhere on the circumference of the roller so long as it enters the magnetic field of magnetic pickup 80 once for each revolution to produce a pulse for each revolution of knife roller 17. Magnetic pickup transducers 80 and 72 comprise a solenoid within which is a permanent magnet. When a ferrous material such as tooth 81 passes within the field of the magnet, the change of flux will produce an output voltage.

While the transducing mechanism and means described thus far disclose the preferred use of magnetic pickups 72 and 80, these could be replaced with electrical contacts which contact physically to make a circuit or by photoelectric transducers.

The time discrimination logic means of the system provides for the counter to count out a length of web and produce a pulse or signal and for the knife transducer means to produce a pulse or signal and to analyze the time relationship between these pulses or signals to direct an increase or decrease in length by means of an appropriate pulse or signal directed toward an appropriate relay which operates a contact connected to the increment size adjustment system which in turn will direct the gear ratio control motor 16. The time discrimination logic means is so constituted that when the counting pulse and the knife pulse occur together within a tolerance hand, there will be no direction to increase or decrease the length of the blank since the cut is being made at precisely the right count or time. If, however, the pulse from the knife transducer leads or lags behind the pulse from the counter, the time discrimination logic means of the system will produce an appropriate signal to either increase or decrease the length of the cut.

The time discrimination logic means comprises a binary flip-flop 85 having a single input 86 and two outputs 87 and 88-. Each successive input pulse into the binary flip-fiop causes each of its two outputs to change state. In the system described herein, we prefer to provide a binary flip-flop in which one output is at minus 6 'volts and the other at 0 volt. When a pulse from the magnetic pickup 80 reaches input 86, the outputs will change and reverse; that is, the output which is then at minus 6 volts will switch to 0 and the output which is then 0 volt will switch to minus 6 volts. The very next impulse will cause the

outputs

87 and 88 to revert to the first stated conditions.

The binary fiip-flop 85 is a two stage, bistable device, 'each of whose outputs are at a different state. Upon application of an input signal, the outputs of the two stages flip or reverse and remain in such state until the next input 'at which time they revert to the original state.

While not absolutely necessary, we prefer to provide an amplifier 89 to amplify the pulse coming from mag ne'tic pickup 80 and lead the signal from the amplifier 89 into a trigger 90, such as a Schmitt trigger, to standardiz'e the wave shape and then lead the pulse into input 86 of the binary flip-flop. Output 87 of the binary flip-flop is connected to input 91 of flip-flop 92. Flip-flop 92 is a bistable multi-vibrator and is similar to binary flip-flop 85 except that it has two inputs and one output. Input 91 is a set and input 93 is a reset. Output 94 is connected to an input 95 of an and gate 96. And gate 96 is placed between magnetic pickup 72 and counter '70. And gate 96 is the type of and gate which has two inputs 95 and 97 and an output :98. When both inputs 95 'and 97 are present with correct polarity and amplitude, the and gate 96 will permit pulses to flow from pickup 72 to counter 70 through input '97 and out of output 98. Thus, counter 70 can only count pulses from pickup '72 when flip-flop 92 is set and permits flow of current from its output '94 to input 95 of and gate 1'6.

The pulse signal emanating from counter 70 is fed into a one-shot multi-vibrator 100. The one-shot multi-vibrator 100 is a mono-stable device being in a steady state condition with its output 101 set to remain at minus 6 volts. However, when a proper signal is sent through its input 102 by an impulse from counter 70, the output 101 will change from minus 6 volts to 0 volt for a specified period of time and then revert back to the steady state condition at minus 6 volts. Its use here is to insure the proper polarity and pulse rise time to activate flip-flop 92. As output 101 is connected to input 93 of flip-flop 92, a pulse passing through one-shot multi-vibrator 100 will act to reset flipdiop 92. In other words, a pulse from output $7 of binary flip-flop will set flip-flop 92 and permit counter 70 to count pulses through and gate 6. When the predetermined number of pulses are counted, a signal from counter 70 will go through one-shot multi-vibrator 100 and reset flipdiop 92 to close and gate and prevent counter 70 from counting.

Output 101 of one-shot multi-vibrator is also connected to inputs 105' and 106 of and

gates

107 and 108, respectively. And

gates

107 and 108 each have three inputs and one output. The

inputs

105 and 106, 109 and 110, 111 and 112 of the two and gates, respectively, will permit each and gate to operate when its three inputs are all at 0 voltage. If any one of the inputs is at other than 0 voltage, no signal will emanate from output 113 or 114, as the case may be, of and gates 10'] and 108. If, on the other hand, all three inputs of either and gate 107 or and gate 108 are at 0, then a pulse will emanate from output 113 or 114 to one-shot multivihrator 115 or 116, as the case may be. One-shot multivibrators 115 and 116 are connected to relay drivers 117 and 118 which are in turn connected through appropriate means to contacts in the increment size adjustment system so that a timed increment signal can be delivered to

connector

40 or 41, as the case may be, of the gear ratio control motor to either increase or decrease the ratio of variable speed transmission 15.

Output 87 of binary flip-flop 85 is also connected to and gate 107 through input 10?. The other output 88 of binary flip-flop 85 is connected through input 110 to and gate 108. The binary flip-flop 85 is also connected through its output 88 to a variable one-shot multi-vibrator 120 through input 121. The output 122 of variable oneshot multi-vibrator 120 is connected to

inputs

111 and 112 of and

gates

107 and 108, respectively.

The variable one-shot multi-vibrator has a tolerance control 123 which permits the control of the duration of the pulse which it emits from output 122. Thus, each time magnetic pickup 30 picks up a pulse from element 81 (which is each time knife cylinder 17 revolves once and makes a cut), the pulse is amplified in amplifier 89, then is triggered through trigger 90 to input 86 of binary flip-flop 85. This will change the state of

outputs

87 and 88 of binary flip-flop 85 from O to minus 6 volts and vice versa. Let us assume that when the system is activated, the binary fiipdiop output 87 is at minus 6 volts and output 88 is at 0. At the first knife out, these states will change so that output 88 will then be at minus 6 volts and output 87 at 0 and so on during the operation of the system. When output 87 is at 0 volt, input 109 of and gate 107 will be at 0 volt, and input 110 of and gate 108 will be at minus 6 volts because it is connected to output 88 which is then at minus 6 volts. Thus, as flipfiop 85 switches, the voltages and

outputs

109 and 110 will switch so that when one is at 0 volt, the other will be at minus 6 volts and vice versa. This means that only one and gate 107 or 103 may have an output at any given time so that the system cannot give conflicting sig nals to increase and to decrease at the same time. This phase relationship is also important in permitting the system to determine when an increase or decrease signal shall be given because as the operation of the counter in connection with the system is described below, it will become apparent that if a knife cut occurs before the signal from the counter, it will be during the time when too short and gate 108 may be activated because input 110 is at and when too long and gate 107 is inhibited because input 109 will be at minus 6 volts. The converse will also follow that if a knife cut signal occurs after the counter signal, it will be during the time when the too long and gate has input 109 at O and may permit an output and when the too short and gate 108 is inhibited because input110 is at minus 6 volts.

Returning now to the outputs of binary flip-flop 85, output 88 changes in voltage and polarity for each input (each knife cut) and causes variable one-shot multi-vibrator 120 to send a pulse of minus 6 volts to

inputs

111 and 112 of toolong and? gate 107 and too short and gate 108 simultaneously. This pulsed signal will act as an

inhibitor tofand gates

107 and 108. At all other times, inputs 1'11 and 112 will be at O and will not inhibit the output of the said and gates.

By the nature of the system, the pulse from variable one-shot multi-vibrator 120 will coincide with the change of voltage and polarity at

inputs

109 and 110. Thus, at the moment of such change of polarity, the pulse from variable one-shot multi-vibrator120 being at minus 6 volts, will inhibit both and gates. However, immediately before or after the pulse from variable one-shot multi-vibrator 120, the and

gate

107 or 108, which has its

input

109 or 110 ,at'O, may permit an output signal through output 113 or 114if the

third input

105 or 106 is at O. (This is the determining factor for output in and

gates

107 and 108 that all three'inp-uts be at 0.) The signal from the counter through multi-vibrator 100 will determine when

inputs

105 and 106 will be at 0. These inputs will be at minus 6 volts at all times except when the signal signifying the end of the count of the counter 70 will place them at 0. I

As. was stated above, the counter 70 will count pulses from the length transducer means. The counter may count only when and gate 96 is in an enabling state with inputs'97 and 95 at proper voltage. This depends on flip-flop 92 being in an on or set state. When output. 87 of binary flip-flop 85 changes polarity and voltage to 0 volt, this signal enters input 91 of flip-flop 92 to place it in set or on position and opens and gate 96 and permits the counter 70 to start counting. Let us say that the counter is set at 600 to measure a blank 60 inches long. At the end of 600 pulses, the counter will emit a signal to input 102 of one-shot multi-vibrator 100 which will send .a pulse out of output 101 to both input 93 of flip-flop 92 and to

inputs

105 and 106 of the and gates. Thistpulse signal will serve to reset flip-flop 92 and prevent further counting. Flip-flop 92 will not be set again until output 87 of binary fliptop 85 is again switched to 0 volt. Thus, the counting cycle is started at every second pickup bymagn etic pickup 80 which means that the length transducer means operates to count after every alternate knife count. By the nature of the system, this will permit'an adjustment in length after every second knife cut when such adjustment is necessary.

It w ill be appreciated that if blanks of exactly 60 inches are being cut, the counter will finish counting at the time the cut is being made. The binary flip-flop 85 will switch at the time the cut is being made and variable oneshotmulti-vibrator 120 will produce its signal at the time the out. is being made. The too long and too short and gates 107 and 108'will both be inhibited because the 0 enabling inputs at 105 and 106 from the predetermined counter 70 will be canceled out by the inhibiting input of minus 6 volts at 111 and 112. By the same token, when the blank is being cut at correct size, the inputs at 105 and 106 will be at minus 6 volts between cuts during the time thatthe counter is either counting or is off. This will inhibit both and gates and no corrective action will -be taken. It willthus be seen that when the blank is being cut', at correct length, and

gates

107 and 108 will be inhibited by a minus 6 voltage at either

inputs

105 and 106 from the counter or at

inputs

111 and 112 from the variable one-shot multi-vibrator 120. A too long or too short signal can only be given when both of these signals are at 0. This can only occur when the counter finishes counting before or after a knife cut.

At this point, we should mention the function of the tolerance control. Since this system is set up to measure by means of pulses spaced at intervals of of an inch, the spread of signal pulse from the one-shot multivibrator should cover a time interval greater than the time it takes to measure of an inch. This is to permit the variable one-shot multi-vibrator 120 signal to overlap the one-shot multi-vibrator 100 signal from the counter 70. Otherwise, a too short or too long signal may be given even though the cut of the blank is accurate to within of an inch. If greater accuracy is desired, it would, of course, be necessary to increase the number of teeth 76 on wheel 73. Doubling the number of teeth would duplicate the pulses and increase accuracy accordingly. For a inch system, the number of teeth would be 12x16 or 192.

We have set forth in FIG. 7 of the drawings a diagram showing the action of counter 70 and multi-vibrator 100 with relation to the switching of binary flip-flop and the inhibit signal from variable one-shot multi-vibrator 120. Reference to column A of FIG. 7 will show the counter counting 600 pulses. At the 600 pulse, counter 70 will emit a signal to operate multi-vibrator which will cause inputs and .106 to be at 0 for a short interval. At exactly this time, the knife has made a premature cut so that output 87 and input 109 are at minus 6 volts and output 88 and input are at 0 volt.

Outputs

111 and 112 are at 0 volt, the inhibit period having expired. Thus, and gate 108, which has all of its

inputs

106, 110 and 112 at 0 volt, will permit an output and signal a too short or increase signal through one-shot multi-vibrator 116 and relay driver 118 to cause an increase in increment adjustment of of an inch. Continuing on to the right of FIG. 7, in vertical column B, at the time the counter 70 has counted out 600 pulses, the knife has not yet cut. Thus,

inputs

105 and 106 will be at 0 volt, input 109 will be at 0 volt, input 110 will be at minus 6 volts and

inputs

111 and 112 will be at 0 volt. In this condition, and gate 108 will. be inhibited and and" gate 107 will send an output through 113 to one shot multi-vibrator 115 and so forth to cause a decrease of 1A0 of an inch through the increment adjustment system to the gear ratio control motor 16. lln column C, the counter and knife cuts both operate at the same time indicating a blank of correct size. Thus, while

inputs

105 and 106 are at 0 volt, inputs 111 and. 112 will both be at minus 6 volts and both

andgates

107 and 108 will be inhibited. 1

While we have described our invention in its preferred form, there are other forms which it may take without leaving the scope of the" invention and we, therefore, desire to be protected for all forms coming within the claims hereinbelow.

1. In a material processing system having material moving and cutting mechanisms including cutter driving means, cutter movement control apparatus for effecting an accurately controlled length for the pieces to be cut ofi comprising: i Y

adjustable means presettable to indicate a desired one of a plurality of cutoff lengths for the pieces; presettable measuring means for measuring a preselected length of material; means operable independently of the material moving mechanism and responsive to said adjustable means when preset for initially adjusting the cutter driving means for the preset cutofi length; the nature of the system being such that the length of i the pieces that are cut might vary from the length sought by said initial adjustment requiring further adjustment under the control of said measuring means;

means responsive to said measuring means upon measurement of said preselected length for providing a measured-length signal;

means for providing an actual-length signal in response to a cutting operation;

means responsive to non-coincidence of these two nals for providing an error signal indicating the direction in which the actual length differs from the measured length;

and step means controlled by said error signal for effecting a small uniform adjustment in the cutter driving means tending to bring subsequent ones of the two signals toward coincidence.

2. The invention defined in claim 1, together with:

means for providing an inhibit signal in synchronism with one of said two signals for preventing said step means from responding unless the difference between the actual length and the measured length is more than a predetermined amount.

3. The invention defined in claim 2, wherein said inhibit signal providing means comprises:

means for adjusting said inhibit signal to vary the magnitude of error for which no correction is made.

4. The invention defined in claim 1, wherein said adjustable means comprises:

an unbalancing device having a pointer which may be manually adjusted along a dial calibrated in small unit lengths of material;

and said means responsive to said adjustable means comprises a follow-up system for adjusting the cutter driving means in accordance with the unbalance and for eifecting a rebalance to stop the adjustment of the cutter driving means.

5. The invention defined in claim 1, wherein said presettable means comprises:

a predetermined digital counter for counting small unit lengths of material and for providing an output signal when it counts out in accordance with its presetting.

6. In a material processing system having material moving and cutting mechanisms including cutter driving means, cutting movement control apparatus for effecting an accurately controlled length for the pieces to be cut olf comprising:

adjustable analog means presettable to indicate a desired cutoff length for the pieces;

presettable digital measuring :means for measuring a preselected length of material;

means effective upon initiation of operation of the apparatus operable independently of the material moving mechanism and automatically controlled by said adjustable analog means for initially adjusting the cutter driving means for the preset cutoff length;

the nature of the system being such that the length of the pieces that are cut might vary from the length sought by said initial adjustment requiring further adjustment under the control of said measuring means;

means in said measuring means for providing a measured-length signal when the preset length of material has been measured;

means for providing an actual-length signal at the time the material is cut;

means for receiving said measured-length signal and said actual-length signal and for providing an error signal indicating whether the actual length is shorter or longer than the measured length by more than a predetermined amount;

and means responsive to said error signal for adjusting the cutter driving means one or more equal discrete steps according to the magnitude of error signal in a direction tending to equalize the actual length with the measured length.

7. In a system for cutting moving material into pieces of predetermined length and including a cutter and driving means therefor, and means for moving the material past the cutter, the combination comprising:

means for preselecting a desired length for the pieces of material to be cut; Y

means automatically controlled by said preselecting means for adjusting the cutter driving means for cutting the desired length of pieces;

means for periodically measuring the material passing the cutter and for producing a measured-length pulse when a predetermined length of material has been measured;

means for producing an actual length pulse in response to each driving of the cutter through its cutting cycle;

means for comparing the time positions of each measured length pulse and the corresponding actual length pulse and for producing an error signal indicative of the direction in which the actual length that has been cut differs from the measured length;

and means responsive to each error signal for adjust ing the cutter driving means a uniform amount so that the length of the next piece will be a discrete unit amount closer to the predetermined length than was the actual length of the piece just cut.

3. The invention defined in claim "7, together with:

means responsive to said actual-length pulse producing :means for providing an inhibit signal of adjustable length and for applying this inhibit signal to said error signal responsive means to inhibit operation of the latter unless the separation of said pulses exceeds the length of the inhibit signal.

9. In an apparatus for correcting the speed of operation of a cutter relative to the speed of flow of uncn material being fed to the cutter;

means for producing a signal proportional to the material fiow speed; means for producing a signal corresponding to the cutter speed;

means for comparing the flow speed signal and the cutter speed signal to determine how much the length of material cut by the cutter is shorter or longer than a predetermined length and a generate a respective error signal;

means responsive to the error signal regardless of its magnitude for correcting the cutter speed to produce pieces of predetermined length; and

means for inhibiting the action of said correcting means when the length of pieces produced is within a predetermined tolerance.

10. An automatic unit length adjustment system for cuting means, comprising: a material drive for driving a web of material to be cut and a cutter drive, and cutting means for cutting said material to a length, including:

a material drive actuated pulse producing means for producing pulses relates to the length of the material to be cut; I

cutting means actuated pulse producing means for producing pulses related to the operation of the cutting means;

counting means to count the said web length related pulses and to send a signal after a selected number of pulses simultaneously to a first input of a first and gate and a first input of a second and gate;

switching means associated with the said cutting means actuated pulse producing means having outputs to to send signals alternately to a second input of said first and gate and a second input of said secon and gate; and 1 signal producing means associated with the cutting means actuated pulse producing means to send in.- hibiting signals simultaneously to a third input of said first and gate and a third input of said second and gate, said first and gate having having an output connected to means to produce adjustment in one direction in the size of the 'materialto be cut,

and said second and gate having an output connected to means to produce adjustment in the opposite direction in the size of the material to be cut, the outputs of said and gates being suppressed during the presence of said inhibiting signals.

11. A length adjustment system as defined in claim 10,

in which:

said first inputs of both and gates are at 0 voltage at end of count time intervals and are at a potential controlled by said counting means between said time intervals;

said second inputs of both and gates are alternately at 0 voltage when a cut is made and at a potential betwen cuts in accordance with the condition of said switching means;

the said third inputs of both and gates are at 0 voltage at all times except when an inhibit potential is impressed by said cutting means actuated pulse producing means; and

each of said and gates produces an output signal only 5 when all of its inputs are at 0 voltage.

References Cited UNITED 15 ANDREW R. JUHASZ, Primary Examiner.

Claims

1. IN A MATERIAL PROCESSING SYSTEM HAVING MATERIAL MOVING AND CUTTING MECHANISMS INCLUDING CUTTER DRIVING MEANS, CUTTER MOVEMENT CONTROL APPARATUS FOR EFFECTING AN ACCURATELY CONTROLLED LENGTH FOR THE PIECES TO BE CUT OFF COMPRISING: ADJUSTABLE MEANS PRESETTABLE TO INDICATE A DESIRED ONE OF A PLURALITY OF CUTOFF LENGTHS FOR THE PIECES; PRESETTABLE MEASURING MEANS FOR MEASURING A PRESELECTED LENGTH OF MATERIAL; MEANS OPERABLE INDEPENDENTLY OF THE MATERIAL MOVING MECHANISM AND RESPONSIVE TO SAID ADJUSTABLE MEANS WHEN PRESET FOR INITIALLY ADJUSTING THE CUTTER DRIVING MEANS FOR THE PRESET CUTOFF LENGTH; THE NATURE OF THE SYSTEM BEING SUCH THAT THE LENGTH OF THE PIECES THAT ARE CUT MIGHT VARY FROM THE LENGTH SOUGHT BY SAID INITIAL ADJUSTMENT REQUIRING FURTHER ADJUSTMENT UNDER THE CONTROL OF SAID MEASURING MEANS; MEANS RESPONSIVE TO SAID MEASURING MEANS UPON MEASUREMENT OF SAID PRESELECTED LENGTH FOR PROVIDING A MEASURED-LENGTH SIGNAL; MEANS FOR PROVIDING AN ACTUAL-LENGTH SIGNAL IN RESPONSE TO A CUTTING OPERATION; MEANS RESPONSIVE TO NON-COINCIDENCE OF THESE TWO SIGNALS FOR PROVIDING AN ERROR SIGNAL INDICATING THE DIRECTION IN WHICH THE ACTUAL LENGTH DIFFERS FROM THE MEASURED LENGTH; AND STEP MEANS CONTROLLED BY SAID ERROR SIGNAL FOR EFFECTING A SMALL UNIFORM ADJUSTMENT IN THE CUTTER DRIVING MEANS TENDING TO BRING SUBSEQUENT ONES OF THE TWO SIGNALS TOWARD COINCIDENCE.