US3820429A - Preprinted cigarette paper registration control - Google Patents

Abstract

In the manufacture of cigarettes utilizing paper having registration marks at spaced intervals, the paper is fed at a constant speed with constant tension while the cigarette cutoff knife speed is varied and consequently the distance between knife cuts to accommodate the presence of varying repeat lengths of paper between registration marks. The registration control circuitry increases the knife speed if the registration mark leads the knife cut, and the knife speed is decreased if the registration mark lagged. An optical sensor senses the registration mark on the paper at a location prior to cutting. A shaft encoder transforms analog mechanical rotation of the cutoff knife into electrical pulses. The output of the encoder is in the form of a pair of pulses one for each knife revolution while the other is in the form of 500 pulses per knife revolution. Both of these outputs are applied to the enable pulse detector circuit of a controller. One of the 500 pulses per knife revolution is chosen as an enabling or start pulse to be applied to a pulse forming circuit. The one pulse per knife revolution output of the encoder resets counters of the enable pulse detector circuit to zero with each revolution. The pulse forming circuit has two inputs including the 500 pulses per knife revolution from the shaft encoder and the enable pulse from the enable pulse detector. The pulse forming circuit produces four outputs including a lead pulse, lag pulse, pulses to a visual indicator, and a knife pulse. The registration mark sensor produces a very narrow output pulse which is applied to the visual indicator and a registration detector circuit. This circuit has four input signals, namely, a lead gate pulse, a knife pulse, lag pulse, and registration mark pulse. Four output signals are produced by the registration detector circuit and applied to a correction speed and direction circuit. These four signals are an ''''automatic'''' pulse, increase knife speed, decrease knife speed pulse and in register pulse. The correction speed and direction circuit has also applied thereto the 500 pulses per knife revolution produced by the shaft encoder. This circuit produces a variable pulse frequency output which is applied to the correction motor in the form of a forward pulse and reverse pulse. The correction motor is a stepping motor which serves to convert digital pulses to mechanical motion, and consequently, adjustment of a differential coupled to the cutoff knife. The activation of the differential results in adjustment of the cutoff knife speed.

Description

United States Patent [191 Harris, Jr.

[ PREPRINTED CIGARETTE PAPER REGISTRATION CONTROL [75] Inventor: Richard C. Harris, Jr., Middletown.

[73] Assignee: Brown & Williamson Tobacco Corporation, Louisville, Ky.

22 Filed: Dec.20, 1972 21 Appl. No.: 316,679

Primary Examiner-.1. M. Meister Attorney, Agent, or Firm-Vance A. Smith 57 ABSTRACT In the manufacture of cigarettes utilizing paper having registration marks at spaced intervals, the paper is fed at a constant speed with constant tension while the cigarette cutoff knife speed is varied and consequently the distance between knife cuts to accommodate the presence of varying repeat lengths of paper between registration marks. The registration control circuitry increases the knife speed if the registration mark leads the knife cut, and the knife speed is decreased if the registration mark lagged. An optical sensor senses the 1 June 28, 1974 registration mark on the paper at a location prior to cutting. A shaft encoder transforms analog mechanical rotation of the cutoff knife into electrical pulses. The output of the encoder is in the form of a pair of pulses one for each knife revolution while the other is in the form of 500 pulses per knife revolution. Both of these outputs are applied to the enable pulse detector circuit of a controller. One of the 500 pulses per knife revolution is chosen as an enabling or start pulse to be applied to a pulse forming circuit. The one pulse per knife revolution output of the encoder resets counters of the enable pulse detector circuit to zero with each revolution. The pulse forming circuit has two inputs including the 500 pulses per knife revolution from the shaft encoder and the enable pulse from the enable pulse detector. The pulse forming circuit produces four outputs including a lead pulse, lag pulse, pulses to a visual indicator, and a knife pulse. The registration mark sensor produces a very narrow output pulse which is applied to the visual indicator and a registration detector circuit. This circuit has four input signals, namely, a lead gate pulse, a knife pulse, lag pulse, and registration mark pulse. Four output signals are produced by the registration detector circuit and applied to a correction speed and direction circuit. These four signals are an automatic" pulse, increase knife speed, decrease knife speed pulse and in register pulse. The correction speed and direction circuit has also applied thereto the 500 pulses per knife revolution produced by the shaft encoder. This circuit produces a variable pulse frequency output which is applied to the correction motor in the form of a forward pulse and reverse pulse. The correction motor is a stepping motor which serves to convert digital pulses to mechanical motion, and consequently, adjustment of a differential coupled to the cutoff knife. The activation of the differential results in adjustment of the cutoff knife speed.

5 Claims, 13 Drawing Figures sum 02 0710 Min Z ATENTEB M 28 1974 saw '05 mm FATENTEUJUR 28 I974 sum usuno m Isa q q q c IIIiIICIIIII PATENTEDJUNZS 1914 SHEU 07B! 10 PREPRINTED CIGARETTE PAPER REGISTRATION CONTROL CROSS REFERENCE TO RELATED APPLICATIONS filed Sept. 23, 1970 and entitled Tube Maker Registration Control, now U.S. Pat. No. 3,688,620.

SUMMARY OF THE INVENTION The present invention contemplates an improved registration control circuitry of the type disclosed in the above-referenced U.S. Pat. application Ser. No. 74,679. Although the present invention will be directed primarily to the maintenance of the cut of cigarettes employing paper having registration marks at prescribed intervals as distinct from the manufacture of spills specifically disclosed in this referenced application, it should be understood that the present invention is equally applicable to spill manufacture. Thus, in the specific embodiment disclosed herein, the registration marks may identify the beginning and end of an invisible printed pattern appearing on the paper. In the case of this paper, as in the case with the ,preprinted cork tipping pattern in the above-referenced U.S. Pat. application Ser. No. 74,679, the registration mark repeat length varies throughout the length of the paper wound on a bobbin. In order to register the knife cut with the registration mark and maintain registration automatically thereafter, the drive of the paper is at constant speed with constant tension and the cutoff knife speed is varied to vary the distance between the knife cuts. In general, the location of the registration mark is sensed and compared to the location of the knife cut. A determination is made whether the registration mark led or lagged the knife cut. The knife speed is increased if the registration mark led and it is decreased if the registration mark lagged.

In the disclosed embodiment, the registration mark is sensed by photocell and light source which are located approximately one repeat length from the cutoff knife. A visual display of the relative position between the knife cut and the registration mark is provided for aiding the operator to manually register before switching to automatic register. As an alternative to an oscilloscope, a visual display device is provided with a rotating neon lamp driven in synchronization with the cutoff knife. The lamp is caused to flash by the signal generated when the registration mark is sensed and the signal incident to whether the knife cut led or lagged the mark. An incremental shaft encoder which is an electromechanical device that transforms analogue mechanical rotation into electrical pulses is coupled with the cutoff knife and produces two signals which are transmitted to a controller, the first output being 500 pulses per knife revolution and the second being 1 pulse per knife revolution. A mechanical differential is coupled with a correction motor as well as the drive of the cutoff knife. The differential has two inputs and one output with one of the inputs being from the main drive shaft and the other from the correction motor. The output of the differential drives the cutoff knife. By varying the speed and/or direction of rotation of the input from the correction motor to the differential, the speed of the cutoff knife is correspondingly varied. Gear ratios between the main drive shaft and the differential and between the cutoff knife and differential are chosen to give the target distance between knife cuts with no input from the correction motor. A stepping motor converts the digital pulses from the controller to mechanical motion which adjusts the differential forpurposes of changing-knife speed. In this matter, registry of the knife cut with the registration marks is ob tained and assured.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:

FIG. 1 A, B and C illustrate segments of cigarette paper having registration marks thereon at prescribed intervals and that are adapted to and handled by the registration controller of the present invention;

FIG. 2 is a schematic and diagramatic view of the controller shown associated with a fragmentary part of the garniture and cutoff knife stations of a cigarette rod making machine;

FIG. 3 is a block diagram of the controller;

FIG. 4 is a circuit diagram of the enable pulse detector;

FIG. 5 is a diagram of the pulse forming circuit;

FIG. 5 B shows the logic signals in the enable pulse and pulse forming circuits;

FIG. 6 is a diagram of the registration detector circuit;

FIG. 7 is a diagram of the rotating neon lamp driver circuit;

FIG. 8 is a block diagram of the correction speed and direction circuit;

FIG. 9 A is the control logic for the up/down binary counter and storage register shown in FIG. 9 B, both forming part of the correction speed and direction circuit; and g FIG. 9 B is the up/down binary counter and storage register of the correction speed and direction circuit.

DETAILED DESCRIPTION Referring initially to FIG. 2, a somewhat conventional continuous rod cigarette making machine 10 receives and delivers cut tobacco to a traveling paper web 12a, 12b or 12c (see FIGS. 1A, 1B, and 1C). Thereafter, the paper and tobacco thereon are continuously fed through the garniture station 14 from which they emerge in the form of the continuous rod 16. The rod 16 passes through the cigarette cutoff mechanism where cutoff knife 18 severs the rod into individual cigarette lengths 20. As explained in the above referenced patent application filed on even date herewith, the cigarette lengths 20 are fed to and picked up by a filter tip attachment machine (not shown) which associates the cigarette length 20 with the selected mouth piece in forming the finished filter cigarette.

For purposes of the present discussion and disclosure of the invention, cigarette paper of the type shown in FIGS. 1A and 18 will be employed in forming the rod 16 and cigarette lengths 20. However, it should be understood that the paper 12c of FIG. 1C may be readily employed for purposes of forming spills in accordance with the disclosure of the above referenced U.S. Pat. application Ser. No. 74,679. Thus, the cigarette paper 12a, 12b and will include Registration Marks 22a, 22b and 220 respectively. The marks 22a and 22b in accordance with a commercial application of the invention were approximately 2 millimeters wide and identify the beginning and end of an invisible printed pattern. Paper 12a was utilized in forming a 100 millimeter filter cigarette while paper 12b formed an 84 millimeter filter cigarette. The distance between knife cuts of both embodiments is shown in the Figures. Of course, the Registration Mark 22c of FIG. 1C is a preprinted cork tipping pattern. In all cases, the Registration Mark repeat length varies throughout the length of paper because of the generally non-uniform stretching thereof during winding and unwinding by the paper supplier.

The present invention controls the registration of the knife cut with the Registration Mark and maintains registration automatically. In the illustrated embodiment diagramatically shown in FIG. 2, registration on the cigarette maker is controlled by driving the cigarette rod 16 at a constant speed while maintaining constant tension on the paper and varying cutoff knife speed to vary the distance between knife cuts. This is accomplished by sensing the RegistrationMark, comparing it to the knife cut, determining whether the Registration Mark led or lagged the knife cut, and increasing the knife speed if the Registration Mark led, or decreasing the knife speed if the Registration Mark lagged. Towards this end, an optical sensor 24in the form of a photocell assembly operates to detect the leading edge of the mark 12a and generate a pulse which is processed by the controller 26. The location of the knife 18 as a cut is made is sensed by a shaft encoder 28 which electromechanically transforms analogue mechanical rotation into electrical pulses related to the knife cut which are transmitted to the controller 26 which operates to compare the location of the knife cut to the Registration Mark sensed by the sensor 24. Determination is then made whether the Registration Mark led or lagged the knife cut; in which case, the knife speed is adjusted. This is accomplished by the actuation of stepping motor 30 which through differential 32 changes the speed of knife 18. The differential 32 allows the position of the knife 18 to be shifted in relation to the main drive. Inasmuch as the main drive is constant, the actuation of the motor 38 when its output is applied to the differential and eventually to the knife 18 determines the correct knife speed'for registration. A visual display 34 described in detail below facilitates manual adjusting of the registry between the knifecut and the Registration Mark 120 by the machine operator before switching controller 26 to Automatic.

Referring now to FIG. 3, the controller 26 is shown in block diagram form associated with the Registration Mark sensor 24, shaft encoder 28, together with the vi-- sual display 34 and correction-motor 30. The shaft encoder 28 is driven by the knife and in the illustrated embodiment is taken to produce 500 pulses per knife revolution as one output and one pulse per knife revolution as another output. Both of these outputs are applied to the Enable Pulse Detector circuit 36. As will be revealed shortly, the Enable Pulse Detector circuit contains counters and thumbwheel switches to allow the operator to choose any one of the 500 pulses per knife, revolution as an Enabling or Start Pulse to be applied to the Pulse Forming circuit 38. The one pulse per knife revolution output of the encoder 28 resets the counters in the Enable Pulse Detector to zero with each revolution.

The Pulse Forming circuit 38 hastwo inputs (l) 500 pulses per knife revolution from the shaft encoder 28, and (2) Enable Pulse from Enable Pulse Detector circuit 36. This circuit 38 produces four outputs. l Lead Pulse, (2) Lag Pulse, (3) Pulses to the visual indicator34, and (4) Knife Pulse.

The Registration Mark Sensor 24 is a photoelectric detector sensing changes in reflected light caused by the Registration Mark 12a. A light source 76, photodiode 78, amplifier 80, and one-shot 82 of FIG. 6 produce a very narrow output pulse to the Registration Detector circuit 42 and through OR Gate 40 to the visual indicator 34 that represents the leading edge of the Registration Mark.

The Registration Detector circuit 42 has four input signals (1) Lead Gate, (2) Knife Pulse, (3) Lag Pulse, and (4) Registration Mark Pulse. In addition to these, the Registration Detector Circuit 42 includes pushbuttons and selector switches to permit the operator to select either a Manual or Automatic mode of operation and, if need be, to-permit him to manually increase or decrease the knife speed. Four outputs are produced by the circuit 42 and applied to the Correction Speed and Direction circuit 44 (1) Automatic, (2) Increase Knife Speed, (3) Decrease Knife Speed, and (4) In Register Pulse.

In addition to the above inputs, the Correction Speed and Direction Circuit 44 has an input of 500 pulses per knife revolution from the shaft encoder 28. As will be explained in greater detail, this circuit 44 uses a binary up/down counter, a storage register, a rate multiplier, and a binary counter to produce a variable pulse frequency output to the correction motor 30. The input from the shaft encoder 28 is the frequency generator for this circuit 44. Two outputs from this circuit go to the motor translator circuit 46 (1) Forward Pulses, and (2) Reverse Pulses. Since the correction motor 30 is a stepping motor, the motor translator 46 converts the input signals to the proper sequence and power level to be applied to the stepping motor 30.

Reference is now made to FIG. 4 showing the Enable PulseDetector circuit 36 shown associated with the shaft encoder 28 together with a chart of the, binary coded decimal thumbwheel switch with the xs closed contacts for the indicated dial positions. When the shaft encoder-28 is rotated by the cutoff knife 18, a pulse train of 500 pulses per knife revolution is fed through a single input AND Gate 48 to the binary coded decimal counters 50. These pulses step the counters 50 up from zero and the count outputs are connected in series with the diodes S2 to binary coded decimal thumbwheel switches 54. The C terminals of the switches are connected to the expander node of an expandable AND Gate 56. The AND Gate 56 produces a logic 1 output whenever the inputs to the diodes 52 selected by the switches 54 are all logic 1.

For example, assume that the decimal 162 is dialed into the thumbwheel switches 54. From the switch chart of FIG. 4, the C terminals of the thumbwheel switches 54 will be connected through diodes 52 to the i nits counter 1, 2 4, and 8 outputs, the tens counter 10, 2Q, 40 ancQQ outputs, and the hundreds counter 100, 200, and 400 outputs Wh en th e counter 6 l ias the degimal No. 162 in it, its 1, 2, 4, 8, 10, 20, 40, 80, 100, 200, and m outputs will each be logic l," and the output of the expandable AND Gate 56 will be logic 1. The one pulse per revolution output of the shaft encoder 28 is connected through an inverter 58 to the Reset or Clear input of the counters 50. This pulse clears the counters 50 to all zeros, allowing the count to start over. By selecting any number between 000 and 499, an Enable Pulse can be created at any 1/500 rotation increment of the cutoff knife 18.

Referring to the pulse forming circuit 38, it ill be evident that an Enable Pulse from the Enable PulseDetector circuit 36 sets flip-flop 58 and 60 to the logic 1" state and produces the 0 pulse through the OR Gate 40 to the visual display 34. The 1 output of flip-flop 58 is ANDed with the encoder pulses through AND Gate 62 and steps the binary counter 64 up from zero. AND Gate 66, 68, 70 and 72 are connected to the counter outputs to detect a number. AND Gate 66 detects decimal No. 30, resets flip-flop 60 producing the Lead Gate at the output of this flip-flop and produces the pulse through the OR Gate 40 to the visual display. The Lead Gate is 30 encoder pulses or 30/500 knife revolutions wide. AND Gate 68 detects decimal No. 35, sets flip-flop 74, and produces the pulse through the OR Gate 42 to the visual display. AND Gate 70 detects decimal No. 65, resets flip-flop 74, and produces the 65 pulse through the OR Gate to the visual display. The output of flip-flop 74 is the Lag Gate and is 30 encoder pulses or 30/500 knife revolutions wide. AND Gate 72 detects decimal No. 32, producing a pulse that represents the knife cut position, and is referred to as the Knife Pulse. When the counter 64 reaches a count of l28, the I28 output resets flip-flop 58, whose 1 output goes to logic 0, disabling AND Gate 62 and clearing the binary counter 64 to all zeros. The pulse forming circuit 38 repeats this cycle for each Enable Pulse.

The Registration Mark Pulse from the Registration Mark Sensor is fed through the OR Gate 40 to the visual display. Since the other pulses applied to the visual display are produced by knife rotation and the visual display is synchronized to the knife rotation, these pulses will be displayed as steady signals and the Registration Mark Pulse will move with reference to these pulses, depending on the conditions of registration.

' In FIG. 6, the Registration Detector circuit 42 is to equal one count output pulse from thebinary counter 64 in the pulse forming circuit 38.

The Registration Mark Pulse is applied to AND Gates 84 and 86, as well as NAND Gate 88. The Lead Gate is the other input to AND Gate 84, the Lag Gate to AND Gate 86 and the Knife Pulse to NAND Gate 88. The output of AND Gate 84 is one input of AND Gate 90, and the output of AND Gate 86 is one input of AND Gate 92. The other input to AND Gates 90 and 92 is the logic 1 when the Mode of Operation switch 94 is in Automatic. Therefore, if the Registration Mark Pulse occurs during the time interval, AND Gate 84 is enabled by the Lead Gate, then AND Gate 84 produces an output to AND Gate 90 which, if the switch 94 is in Automatic, produces a pulse output through OR Gate 96 called Increase Knife Speed. Should the Registration Mark Pulse occur during the Lag Gate interval, then a pulse output is produced through AND Gates 86 and 92 and OR Gate 98 called Decrease Knife Speed." Should the Registration Mark occur during the Knife Pulse, then NAND Gate 88 produces an output called the In Register Pulse. Should the Registration Mark Pulse occur outside of the Lead, Lag and Knife Pulse intervals, then OR Gate 96 and 98 and NAND Gate 88 have no automatic outputs and the control will not make a change in the knife speed.

The operator must manually increase or decrease the knife speed until the Registration Mark occurs during the Lead-Lag Gates or Knife Pulse intervals. This is done by placing the Operation Mode switch 94 in Manual" and depressing either the Slow or Fast Speed pushbuttons 91a or 91b. The Slow Increase or Decrease pushbutton 91a will change the speed of the knife one increment per actuation. The Fast Increase or Decrease pushbutton 91b allows the knife speed increments to be changed at the rate of one speed increment change per knife revolution. Pushing any of the pushbuttons applies a Logic 0 through the connected contact filter 93 to the input of an Inverter 95, which produces a Logic 1 as its output.

Assuming that the Slow Increase Knife Speed pushbutton is pushed once and released, then the output of Inverter a goes from a Logic 0 to Logic 1 and back toLogic 0, creating a pulse that is applied to OR Gate 99a. Now assume that the Fast Increase Knife Speed push-button is pushed. The output of Inverter 95b will then be Logic 1, allowing the Knife Pulse to be applied through AND Gate 97a to OR Gate 99a. The output of OR Gate 99a is connected to OR Gate 96 which passes the pulses on to the Correction Speed and Direction Circuit as Increase Knife Speed Pulses. The action of the Manual Decrease Knife Speed is the same as Increase Knife Speed. The output of OR Gate 99b is connected to OR Gate 98, which passes the pulses on to the Correction Speed and Direction Circuit as Decrease Knife'Speed Pulses.

The visual display 34 in the form of a rotating neon lamp is illustrated in circuit form in FIG. 7. The neon lamp 100 is mounted on a disc and receives electrical pulses through slip rings and brushes shown generally at 102. The disc and consequently the lamp are connected to the drive of the cutoff knife 18 at a 1-to-1 ratio so that at any given increment of knife rotation, the neon lamp 100 has rotated the same increment and therefore remains in synchronization with the knife 18. By applying voltage pulses large enough to fire the neon lamp 100, a spot of light is created as the disc rotates. The length of the lamp spot is equal to the pulse width, and pulses that create non-moving light spot displays occur at the same point of each knife revolution. The 0 pulse (leading edge of Lead Gate), 30 pulse (trailing edge of Lead Gate), 35 pulse (leading edge of Lag Gate), and 65 pulse (trailing edge of Lag Gate), are steady displays of light spots approximately 1/250 360 wide. The Registration Mark Pulse appears as a non-stable light spot, and the distance between the Registration Mark Pulse and the center of the 30 and 35 lamp spots represents the knife cut distance from the Registration Mark. In accordance with the pecific workable embodiment, the circuit 34 included a stepdown power supply 104, DC. driver 106 and a step-up transformer 108. Pulses from the pulse forming circuit 38 turn on the DC. driver 106, which conducts current through the primary of the transformer 108 for the duration of the pulse. The voltage drop across the primary is stepped up on the secondary and applied to the neon larnp 100 through a diode 109, current limiting resistor 110, and the slip rings 102, causing the neon lamp 100 to conduct.

Referring now to the Correction Speed and the Direction circuitry of FIGS. 9A and 98, it should be noted that the control logic for the up/down binary counter 11 1 and the storage register 112 is shown in FIG. 9A. The up-down counter 111 and storage register 112 is shown in FIG. 9B. The purpose of the Correction Speed and Direction circuit 44 is to convert Increase Knife Speed, Decrease Knife Speed, and In Register Pulses to a pulse frequency that drives the correction motor 30 at the proper speed and direction for varying the knife speed to match the Registration'Mark repeat lengths. Rotation of the motor 30, depending on its direction either adds to the speed of the input from the main drive shaft, or subtracts from it, thus producing an output speed that is the algebraic sum of the two inputs.

With no input from the correction motor, the gear ratios between the main drive shaft and the differential 32 and between the differential and the cutoff knife 18 are so chosen to produce a cutoff length that is equal to the specified Registration Mark repeat length of the paper to be registered. As the repeat length varies, the Registration Mark Pulse will occur during the Lead Gate (FIG. 6) if the repeat lengths are short, producing Increase Knife Speed Pulses to the control logic of FIG. 9, or it will occur during the Lag Gate, producing Decrease Knife Speed Pulses if the repeat lengths are too long.

The Correction Speed and Direction circuit of FIG. 9A senses the first Increase or Decrease Knife Speed Pulse, coming from the Registration Detector circuit of FIG. 6, steps the counter 111 (FIG. 5) one count in the proper direction, clears the storage register 112 and reads the contents of the counter 111 into the storage register 112. The second and succeeding Knife Speed Pulses continue to step the counter 111 until the Registration Mark Pulse occurs in time with the Knife Pulse, producing an In Register Pulse (See FIG. 6). When the In Register Pulse occurs in the circuit of FIG. 9A, it clears the counter 111 and reads the contents of the storage register 112 into the counter. This allows the correction motor 30 to be increased to its maximum speed, if necessary, to bring the knife cut into register, yet brings the correction motor speed hack to a point that is only one speed change increment different from the speed when the knife 18 went out of register. If this new speed of the correction motor 30 is not enough to hold the register, then the cycle will repeat, adding one count to the counter 1 11, when the first Increase or Decrease Knife Speed Pulse occurs. For discussion purposes in explaining the operation of the circuits of FIG. 9A and 98. it will be assumed that the knife cut is in register with the Registration Mark 22a, the Registration Detector Circuit (FIG. 6) is producing an In Register Pulse, and the Mode of Operation is Automatic. The In Register Pulse is connected to one input of NAND Gate 114 (FIG. 9A), and the output of NAND Gate 116 produces the second input to NAND Gate 114. NAND Gates 114 and 116 form aset-reset flipflop and when the first In Register Pulse occurs, this flip-flop is set with NAND Gate 114s output, a logic 1, and NAND Gate 1l6s output, a logic 0. Since NAND Gate 114 has the output of NAND Gate 116 as an input, the logic 0 prevents NAND Gate l14s output from changing. The logic 1" to 0" transition of NAND Gate 116s output triggers the one-shot 118, which produces a 10 microsecond negative going pulse at its 0 output to clear the counter 111 to all zeros. This same pulse is delayed 5 microseconds by the element 120 and applied to the counters Presct" input. The counter 111 reads-in the binary number stored in the storage register only when a logic 0" to "1" transition occurs on its .Preset input. Therefore, 5 microseconds after the counter clear pulse, the counter is Preset.,The 1 output of the one-shot 118 is a 10 microsecond positive going pulse connected to one input of NOR'Gate 122, a 10 microsecond DELAY element 124, AND Gate 126, and AND Gate 128. The combined undelayed input and delayed input from oneshot 118 to NOR Gate 122 creates a 20 microsecond interval during which one of the inputs are logic 1, holding NOR Gate l22s output to a logic 0" while the counter is Cleared and Preset. AND Gate 126 has an input from flip-flop s 0 output and flip-flop 132s 1 output. If both of these inputs are logic 1, then the 1 output of one-shot 118 is gated through to an input of NOR Gate 134, which produces an output that toggles flip-flop 130. AND Gate 128 has an input from flipflop 130s output and flip-flop 132 s 0 output. If both of these inputs are logic 1," then the 1 output of one-shot 1 18 is gated through AND Gate 128 and NOR Gate 134 to toggle flip-flop 130. How information gets into flip-flop 132 will be discussed later, but it contains a logic 1 on its 1 output if the direction was FORWARD when out of register conditions occurred, or a logic 1 on its 0 output if the direction was REVERSE. Since flip-flop 130 may change states during the control process of bringing the knife 18 back into register, the AND Gates 126 and 128 gating will change flip-flop 130 to its original state on the first In Register Pulse. As long as the knife 18 stays in register with the Registration Mark 22a, no further change in the counter 111 occurs.

The output of the up/down counter 1 11 is connected to a Rate Multiplier 136. The other-inputs to the Rate Multiplier 136 are from a binary up counter 138. This counter 138 is driven by the 500 pulses output of the encoder 28. Basically, a Rate Multiplier is a frequency multiplexer and, as used here, the up/down counter 1 11 selectsthe frequencies produced by the up counter 138 to be multiplexed. The output (f,) of the Rate Multiplier is equal to the frequency (F) of the shaft encoder 28 times the number contained in the up/down counter 111, divided by 256 (see FIG. 9B). Since the binary up/down counter 111 can only count to 255 in 8-bits, the maximum output (f,) of the Rate Multiplier is 255/256 (F). The output of the Rate Multiplier 136 is divided by four in the 4-bit counter 140 and applied to NAND Gates 142 and 144 (FIG. 9B).

Assuming that the repeat lengths of the Registration Mark 22a begin to get shorter, the Registration Mark Pulse will begin to move towards the Lead Gate. When the Pulse occurs within the Lead Gate, the Registration Detector Circuit 42 provides an Increase Knife Speed Pulse. In FIG. 9A, the Increase Knife Speed Pulse is connected to one input of AND Gate 146 and AND Gate 148. If the In Register conditions had flip-flop 130 producing a FORWARD output and the up/down counter 111 is not at maximum count, then AND Gate 146 allows the Increase Knife Speed Pulse to be applied to OR Gate 150, which drives Inverter 152, OR Gate 154, and OR Gate 156. OR Gate 154 and AND Gate 158 form an AND-OR flip-flop which is set to a logic 1 output, enabling the counter 111 to count-up, and driving the output of Inverter 160 to when the first Increase Knife Speed Pulse occurs. The l to 0" transition of the Knife Speed Pulse is allowed to pass through OR Gate 156 by the output of Inverter 160 being 0. Since both inputs to AND Gate 162 are normally 1, the output of OR Gate 156 is allowed through AND Gate 162 to step the counter 111. When the output of inverter 152 goes to logic 0, the output of NAND Gate 116 goes to 1, Resetting" the NAND Gates 116 and 114 flip-flop to a 1 output of NAND Gate 116 and 0 output of NAND Gate 114. The l to 0 transition of NAND Gate ll4s output triggers one-shot 164, whose 0 output clears the storage register 112 with a millisecond pulse. After 10 milliseconds, the l output of one-shot 164 goes from a 1 to 0 and triggers one-shot 166, whose 1 output causes the storage register 112 to read-in the contents of the up/down counter 111 and flip-flop 132 to shift the data present at its input 132a to its 1 output. If the direction was FORWARD, then flip-flop 132s 1 output would be logic 1, and the 0 output would be 0 after the storage register Read Pulse returned to 0. The outputs of flip-flop 132 would, of course, be in the opposite state if the direction was RE- VERSE. This explains the events of the first Increase Knife Speed Pulse. In this connection, the up/down counter 111 was changed by one count, changing the frequency out of the Rate Multiplier 136 by 1/256 (F) increment, resulting in an Increase in Knife Speed. The contents of the up/down counter 111 and the direction of correction motor rotation was stored in the storage register 112 and flip-flop 132. If this change in Knife Speed was not enough to bring the knife cut into register with the Registration Mark 22a, this will be sensed by the next Lead Gate Registration Mark Pulse occurence, and another Increase Knife Speed Pulse will be produced. Since the NAND Gates 116 and 114 flipflops were Reset and the AND-OR flip-flop (154-158) was Set by the first pulse, the second and succeeding Increase Knife Speed Pulses pass through OR Gate 156 and AND Gate 162 to step the counter 111 up. This action will continue until the knife cut occurs in register with the Registration Mark Pulse or the up/down counter 111 contains a maximum count. A maximum count of 255 is sensed by NAND Gate 168 (FIG. 9B), producing a 0 output when all of its inputs are 1. The Logicf0 output of NAND 168 disables Gates 146 and 170 (FIG. 9A), preventing any pulses from getting through to OR Gate 150, thus preventing further up-counts to the counter.

Heretofore, the control action of the correction speed and direction circuit of FIGS. 9A and 98 have been traced during an In Register condition and an Out-Of-Register condition requiring an Increase in Knife Speed. Now, an Out-Of-Register condition will be assumed requiring a Decrease in Knife Speed. This will happen when the repeat lengths begin to get longer than what they would be at the point of register. Starting with In Register conditions, it will be assumed that the counter 111 contains a count and the correction motor is FORWARD. When the Registration Mark Pulse occurs during the Lag Gate, the Registration Detector circuit 42 of FIG. 6 produces a Decrease Knife Speed Pulse. This pulse is applied to AND Gates 172 and 170 and since the direction is FORWARD. only AND Gate 172 conducts, producing the Decrease Knife Speed Pulse at the output of OR Gate 174. When the output of OR Gate 174 goes to logic I, the output of Inverter 176 goes to logic 0, and since the counter 111 contains a number, the output of NOR Gate 122 will be 0, disabling AND Gate 178, and the output of Inverter 180 will be l," allowing the output of NAND Gate 182 to go to 03' This 0" output of NAND Gate 182 Resets the AND-OR flip-flop (154-158) to a 0" output to the counter count direction, setting the counter 111 for a down-count. Also, if this is the first Decrease Knife Speed Pulse, the output of NAND Gate 182 Resets the NAND Gate flip-flop (114-116) through an input to NAND Gate 116, the a same as the first Increase Knife Speed Pulse. Having set the counter 1 11 for a down-count, the output of NAND Gate 182 passes through AND Gate 162 to step the counter 111 down on the 0 to l transistion of the pulse. The count is read into the storage register 112 and the direction (FORWARD) read into flip-flop 130. If this did not change the speed of the knife 18 enough to bring it into register, the Lag Gate and Registration Mark Pulses will produce further Decrease Knife Speed Pulses. It will be assumed that at this juncture, the repeat lengths continue to grow longer, causing the control to step the counter 111 down, attempting to Decrease the Knife Speed to maintain register. When the counter 111 counts down to zero, NOR Gate l22s output goes to logic 1 enabling AND Gate 178, allowing the inverted Decrease Knife Speed Pulse to toggle fliptlop through NOR Gate 134, switching the direction from FORWARD to REVERSE. This change in direction routes the Decrease Knife Speed Pulse through AND Gate 170 to step the counter 111 up. Note Also that the Increase Knife Speed Pulse (if one should occur) is routed through AND Gate 148 to down-count the counter 111. The rest of the circuit functions the same, except the output of 4-bit counter (FIG. 9B) is routed through NAND Gate 114 and sent to the correction motor translator as Reverses Pulses. Basically, this action of the control allows the correction motor to be increased to a maximum speed in one direction or decreased in speed until zero speed, and increased to a maximum speed in the opposite direction, depending on the requirements of maintaining register.

When the Mode of Operation switch is in Manual (FIG. 6), Increase Knife and Decrease Knife Pulses from the Registration Detector circuit 42 of FIG. 6 are manual inputs. The Automatic" input to the circuit of FIG. 9A will be logic 0, holding the output of NAND Gate 116 to a logic 1, preventing the counter 111 from being cleared/preset during manual operation. If In Register Pulses occur, they will pass through NAND Gate 114, clearing and reading into the storage register 112 the contents of the up/down counter 1 11. This will keep the contents of the storage register close to the value of the counter 111 when manually registering, and allows the control to take over from the manual point of register when switched to automatic.

Thus, the present invention provides for the registration of a cutting knife with the center of a Registration Mark on cigarette paper in the manufacture of cigation assures that the knife cut is within a certain tolerance of the center of the Registration Mark. Although a single somewhat preferred embodiment of the invention has been disclosed and described in detail herein, it should be understood that this invention is in no sense limited thereby and its scope is to be determined by that of the appended claims.

I claim:

1. An apparatus for cutting continuous paper being moved under constant tension wherein the paper has markings repeating at intervals comprising a. rotatable knife means for cutting the paper at the markings;

b. electromechanical encoder means for transforming analogue rotation of the knife means into a train of pulses;

c. sensing means for sensing when the marking is adjacent the knife means and for providing a registration pulse corresponding thereto;

(1. pulse forming means responsive to the train of pulses for providing lead, lag, and knife pulses;

e. correction step motor means for adjusting the knife speed so that the cut is maintained in registration with the markings on the paper;

f. registration detection means for providing an inregister pulse upon simultaneous occurrence of the knife and registration pulses; and

g. control means and a storage means responsive to simultaneous occurrence of knife pulse and lead pulse for 1. reading speed value of said motor means changed by a predetermined increment into said storage means, and for 2. changing speed of said motor means until an inregister pulse is received;

said control means in response to simultaneous occurrence of knife pulse with a lag or lead pulse reading speed value of said motor means changed by a predetermined increment into said storage means and changing speed of said motor means until an in-registcr pulse is received;

said control means in response to an in-register pulse reading the changed correction motor speed out of said storage means and changing the motor means speed to the value read out of said storage means.

2. The apparatus of claim 1 in which said registration detection means provides achange-knife-speed pulse with each simultaneous occurrence of the knife pulse with the lead or lag pulse and said control means is responsive to the change-knife-speed pulse for changing the speed of said motor means.

3. The apparatus of claim 2 in which said control means includes a counter means for incrementally controlling the speed of said correction step motor means, said counter means in response to the first changeknife-speed pulse reading the speed value of said motor means changed by one increment into the storage means, said counter means in further response to each succeeding occurrence of change-knife-speed pulse stepping said motor means until the occurrence of an in-register pulse.

4. The apparatus of claim 1 including visual means responsive to pulses received from said pulse forming means and sensing means for providing a visual display of the relative position between the knife cut and registration mark.

5. The apparatus of claim 1 wherein the registration detection means includes manually operable means for selecting manual and automatic modes of operation and for manually increasing and decreasing knife speed.

Claims (6)

1. An apparatus for cutting continuous paper being moved under constant tension wherein the paper has markings repeating at intervals comprising a. rotatable knife means for cutting the paper at the markings; b. electromechanical encoder means for transforming analogue rotation of the knife means into a train of pulses; c. sensing means for sensing when the marking is adjacent the knife means and for providing a registration pulse corresponding thereto; d. pulse forming means responsive to the train of pulses for providing lead, lag, and knife pulses; e. correction step motor means for adjusting the knife speed so that the cut is maintained in registration with the markings on the paper; f. registration detection means for providing an in-register pulse upon simultaneous occurrence of the knife and registration pulses; and g. control means and a storage means responsive to simultaneous occurrence of knife pulse and lead pulse for 1. reading speed value of said motor means changed by a predetermined increment into said storage means, and for 2. changing speed of said motor means until an in-register pulse is received; said control means in response to simultaneous occurrence of knife pulse with a lag or lead pulse reading speed value of said motor means changed by a predetermined increment into said storage means and changing speed of said motor means until an in-register pulse is received; said control means in response to an in-register pulse reading the changed correction motor speed out of said storage means and changing the motor means speed to the value read out of said storage means.

2. changing speed of said motor means until an in-register pulse is received; said control means in response to simultaneous occurrence of knife pulse with a lag or lead pulse reading speed value of said motor means changed by a predetermined increment into said storage means and changing speed of said motor means until an in-register pulse is received; said control means in response to an in-register pulse reading the changed correction motor speed out of said storage means and changing the motor means speed to the value read out of said storage means.

2. The apparatus of claim 1 in which said registration detection means provides a change-knife-speed pulse with each simultaneous occurrence of the knife pulse with the lead or lag pulse and said control means is responsive to the change-knife-speed pulse for changing the speed of said motor means.

3. The apparatus of claim 2 in which said control means includes a counter means for incrementally controlling the speed of said correction step motor means, said counter means in response to the first change-knife-speed pulse reading the speed value of said motor means changed by one increment into the storage means, said counter means in further response to each succeeding occurrence of change-knife-speed pulse stepping said motor means until the occurrence of an in-register pulse.

4. The apparatus of claim 1 including visual means responsive to pulses received from said pulse forming means and sensing means for providing a visual display of the relative position between the knife cut and registration mark.

5. The apparatus of claim 1 wherein the registration detection mEans includes manually operable means for selecting manual and automatic modes of operation and for manually increasing and decreasing knife speed.

Images