US3739968A

US3739968A - Registration control timing switch for web-processing machine

Info

Publication number: US3739968A
Authority: US
Inventors: R Bodendoerfer
Original assignee: Paper Machinery Corp
Current assignee: Paper Machinery Corp
Priority date: 1971-12-29
Filing date: 1971-12-29
Publication date: 1973-06-19
Anticipated expiration: 1990-06-19

Abstract

Web-cutting apparatus wherein an individual cutting zone on a web must be properly positioned (i.e., in register) relative to a cutting blade at a predetermined time to insure a proper cut requires control means, including a timing or selector switch, for determining if registry exists and for making appropriate changes in web speed if it does not. The timing or selector switch comprises a rotatable shaft synchronized with operation of the cutting blade. A pair of ferrous metal discs are mounted on and rotatable with the shaft. Each disc has a notch in its periphery, and a pair of magnetic pickup devices, one for each disc, are mounted in fixed positions relative to their respective discs. Each pickup device provides an electrical pulse upon passage of the notch in its associated disc as the latter rotates. The interval between the pulses produced by the two pickups for each rotation of the shaft serves as the desired time interval. The duration of the time interval can be varied by changing the angular distance between the pickup devices by moving either one or both to a different position. The time interval itself can be shifted by changing the positions of both pickup devices without changing the angular distance between them to effect advancement or retardation of the web to achieve registry.

Description

United States Patent Bodendoerfer June 19, 1973 REGISTRATION CONTROL TIMING SWITCH FOR WEB-PROCESSING MACHINE [75] Inventor: Raymond E. Bodendoerfer,

Brookfield, Wis.

[73] Assignee: Paper Machinery Corporation,

Milwaukee, Wis.

[22] Filed: Dec. 29, 1971 [21] Appl. No.: 213,502

52 us. C1. 226/30, 83/74 7/1963 Huck 226/30 X Primary Examiner-Richard A. Schacher Assistant Examiner-Gene A. Church Attorney-James E. Nilles [57] ABSTRACT Web-cutting apparatus wherein an individual cutting zone on a web must be properly positioned (i.e., in register) relative to a cutting blade at a predetermined time to insure a proper cut requires control means, including a timing or selector switch, for determining if registry exists and for making appropriate changes in web speed if it does not. The timing or selector switch comprises a rotatable shaft synchronized with opera tion of the cutting blade. A pair of ferrous metal discs are mounted on and rotatable with the shaft. Each disc has a notch in its periphery, and a pair-of magnetic pickup devices, one for each disc, are mounted in fixed positions relative to their respective discs. Each pickup device provides an electrical pulse upon passage of the notch in its associated disc as the latter rotates. The interval between the pulses produced by the two pickups for each rotation of the shaft serves as the desired time interval. The duration of the time interval can be varied by changing the angular distance between the pickup devices by moving either one or both to a different position. The time interval itself can be shifted by changing the positions of both pickup devices without changing the angular distance between them to effect advancement or retardation of the web to achieve registry.

7 Claims, 10 Drawing Figures PATIENIED 3.739.968

sum 1 or 4 ADVANCE ZONE -2l RETARD ZONE FIG. 3

PAINTED- 9973 same er 1:

REGISTRATION CONTROL TIMING SWITCH FOR WEB-PROCESSING MACHINE BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates generally to registration control systems for web-processing apparatus, such as cutting machines which cut blanks from a web of material containing repeated printed designs. More particularly, it relates to timing or selector switch means used in such control systems to achieve registry.

2. Description of the Prior Art Typical apparatus for cutting blanks from a web of material containing repeat printed designs and corresponding register marks comprises a reciprocating cutting blade, intermittently-active feed rolls synchronized with the blade cycle for feeding a predetermined length of web to the blade, and continuously-active constant speed metering rolls which control web speed and, thus, the amount of web fed to the feed rolls. The metering rolls are driven through a variable speed transmission device which incorporates a correction motor which is selectively energizeable by a correction signal for rotation in either direction for short periods of time to make minor momentary adjustments in web speed, i.e., web length fed to the feed rolls. Such speed adjustments are necessary to avoid misregistration of the designs with the cutting blade due to undesirable and unpredictable minute differences in spacing between designs which arise during printing of the design on the web.

Detection and correction of potential misregistration is accomplished by a control system which detects the position of a particular register mark with respect to the blade at a given point in time in the operating cycle of the blade. If it appears that the register mark is in registry, no correction signal is sent by the control system to the correction motor. However, ,if misregistration is indicated and correction is required, the control system provides an appropriate control signal (advance or retard) to the correction motor to momentarily change web-feed speed. Some control systems include a photoelectric scanner located in a predetermined distance ahead of the blade for sensing the passage of register marks printed on the edge of the web (one mark being provided for each design) and for providing a register mark pulse upon passage of each mark. Such control systems further include a timing or selector switch responsive to blade position for defining a scanning area, for each cycle of blade operation. The scanning area is divided into an advance zone, an inregister zone, and a retard zone. Such control systems also include circuitry for determining where each register mark pulse from the scanner occurs in the scanning area and provides an appropriate correction signal to the correction motor.

In practice, it sometimes happens that the designs printed'on the web extend into the region seen" by the scanner, i.e., the scanning area, and this would ordinarily result in false pulses being produced by the scanner. To compensate for this, it is necessary to be able to narrow the so-called scanning area seen by the scanner. It is also necessary to be able to shift the scanning area by manual controls so as to achieve prope registration.

Some prior art timing switches are capable of providing either or both of these functions. One such type of prior art timing switch employs a rotating electrically conductive disc with a non-conductive insert in the periphery and commutating brushes which ride on the periphery of the disc. In such switches, the size of the insert determines the size of the scanning area and the in register interval and changing the position of the brushes shifts the scanning area. However, to make desirable adjustments in some installations, the cutting machine and switch must be stopped and the discs must be replaced or the brushes repositioned. While such prior art timing or selector switches are generally satisfactory for their intended purpose, it is impossible to make adjustments by means embodied in the switch itself. Furthermore, switches using the commutation principle are subject to mechanical wear which can affect their electrical operation and necessitates replacement of worn parts.

SUMMARY OF THE INVENTION Web-processing apparatus and control means therefor in accordance with the present invention contemplates a web containing repeated designs and corresponding register marks along the side edge of the web (normally one mark for each design). Minute errors in spacing occur between each design due to printing techniques employed. Furthermore, portions of each design lie in the same path on the web as the register marks and tend to give false indications to the sensing device unless appropriate measures are taken.

The web-processing apparatus comprises a processing device, such as a cutter, for performing a process or operation on each design; a feed means, such as intermittently operable feed rollers, for repeatedly feeding a predetermined length of web to the cutter; and a metering means, such as constant speed metering rollers, for controlling the rate of speed at which the web is supplied to the feed, i.e., the amount of web supplied to the feed rollers.

The control means for maintaining the designs in registry with the processing device or cutter comprise correction means, such as a differential gear box through which the metering rollers are driven and a selectively energizable correction motor (operable momentarily in forward or reverse) on the transmission, for momentarily changing web speed. The control means also comprise scanning means, such as a photoelectric sensing device, a predetermined distance ahead of the cutter for sensing passage of each registry mark and for providing a register mark pulse in response thereto. The control means further comprise a selector or tim ing switch, hereinafter more fully described, responsive to the operative position of the cutter during each cycle of cutter operation for providing output signals which define a scanning area (actually a time interval) within which or during which the register mark pulse must occur in order for a proper cutting operation to ensue or for appropriate advance or retard adjustments to be made to web speed. The control means finally comprise a control circuit for comparing the relationship of the register mark pulse from the scanner with the scanning interval from the selector switch and for providing a correction signal (advance or retard) to the correction motor in the event the register mark pulse occurs at a time other than during a so-called dead area or in register zone in the scanning interval.

In accordance with the present invention, the selector or timing switch is designed so that the scanning interval can be adjusted in two ways. First, the size (measured in the direction of web travel) of the scanning interval can be adjusted so as to prevent false signals from the scanner (caused by the scanner seeing portions of designs as well as register marks) from effecting a change in web speed. Second, the position of the scanning interval can be shifted to advance or retard web speed so that cutting occurs in the proper place on the web. The selector or timing switch comprises a support frame and rotatable drive shaft mounted on the frame and rotatable at least one revolution for each cycle of cutter operation, although other ratios are possible. Two circular discs of magnetizable metal are mounted on the shaft and are rotatable therewith. Each disc is provided with a notchor cutout in the periphery which provides a magnetic discontinuity in the disc. The discs are preferably disposed so that the notches are spaced 180 apart. A pair of magnetic pickup devices, one for each disc, is mounted on adjustable yokes on the frame. The magnetic pickups are spaced apart from each other by a predetermined angular distance and have a predetermined location with respect to the frame. Each complete revolution of the shaft and discs causes the magnetic pickups to produce a pair of spaced-apart electrical pulses and the interval between the pulses corresponds to the scaning interval. Means are provided to shift the magnetic pickup yokes either to change the length of the interval or to shift it so as to advance or retard web speed.

Controls for web-processing apparatus in accordance with the invention employ an improved timing or selector switch which defines a so-called scanning area which can be selectively adjusted in several ways while the web-processing apparatus and switch are in operation. In particular, the length of the scanning area or the position of the scanning area or both can be adjusted. Furthermore, no contact or friction occurs between switch components which produce electrical pulses and, consequently, no wear occurs and no replacement parts are needed. Adjustment or changes of output signals from the selector switch can be accomplished without the necessity of substituting components of different size or configuration and the switch is ideally suited for high-speed operation.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram of web-cutting apparatus incorporating cut-off register control means in accordance with the present invention;

FIG. 2 is a cross-section view of the web-cutting apparatus shown schematically in FIG. 1;

FIG. 3 is an enlarged top plan view of a portion of the web shown in FIGS. 1 and 2;

FIG. 4 is an enlarged front elevation view of a selector switch shown in FIG. 1;

FIG. 5 is a front view, partly in phantom, of the selector switch shown in FIG. 4;

FIG. 6 is a cross-section view of the selector switch taken along line VI--Vl of FIG. 5;

FIG. 7 is a top plan view of the selector switch shown in FIGS. 4, 5 and 6;

FIG. 8 is a cross-section view of locking devices on the selector switch taken along line VIII--VIII of FIG.

FIG. 9 is a cross-section view of a portion of the cutter adjustment means on the selector switch taken along line IXIX of FIG. 4; and

FIG. 10 is a circuit diagram of portions of the control means shown in FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1 of the drawings, there is shown schematically a web-cutting machine and control circuitry therefor in accordance with the present invention. The cutting machine operates to cut blanks from a web 10 of material, such as paper, on which evenly spaced, repeat designs 112 are printed, as shown in FIG. 3. Web 10 is provided in a path along one edge thereof with evenly spaced printed register marks 14, one mark being provided for each design. However, minute errors occur in spacing between successive designs and successive register marks caused during printing. Typically, each register mark 14 has a width (measured in the direction of web travel) of about 3/32 inch to inch. Furthermore, in some instances, the designs extend into the path occupied by the register marks and this results in erroneous cutting.

WEB CUTTING MACHINE As FIGS. 1 and 2 show, the cutting machine comprises a suitable supporting framework or structure 16 on which a web supply roller 18, decurling rollers 20, web guides 22, and web-support plates 24 are mounted and through or around which web 10 passes. The cutting machine also comprises metering means, such as a metering roll 26 and an associated nip-roller 28 which normally feeds web 10 at a predetermined constant rate of speed to web feeding means, such as a pair of intermittently

operable feed rollers

30 and 32. The

feed rollers

30 and 32, which are adjustable, periodically feed a predetermined length of web to intermittently operable cutting means such as the cutting blades or dies 34 and 36.

As FIG. 2 shows, operating power for the cutting machine is provided by a main drive electric motor 38 which rotates a main drive shaft 40 through a drive means 42. Main drive shaft 40 is connected through a drive means 44 to drive an eccentric cam 46 to which a reciprocally movable cutter blade drive rod 48 is connected. Drive rod 48 effects reciprocating cutting movement of movable blade or die 34 at a constant rate of speed. Main drive shaft 40 is also connected through another drive means 50 to drive a secondary drive shaft 52 which is mounted for rotation on framework 16. Secondary drive shaft 52 is connected through a gear train 54 to drive the

feed rollers

30 and 32 which rotate intermittently. It is to be understood that the movable cutting blade or die 34 operates in synchronism with the

feed rollers

30 and 32, i.e., each advance of a blank by the feed rollers is followed by a corresponding cutting operation. Furthermore, it is to be understood that the gears in gear train 54 are so-called change gears which are replaceable by gears of various sizes depending on the size of the blanks to be cut from the web.

Secondary drive shaft 52 is also connected through another drive means 56 to the input gear 58 of a differential transmission 60 which has an output gear 62 for driving metering roll 26.

Differential transmission 60 is provided with a correction motor 64 momentarily energizable in forward or reverse directions to increase or decrease, respectively, the speed of output gear 62 and thus change the speed of metering roll 26 and the amount of web fed thereby to feed

rollers

30 and 32.

A timing or selector switch 68, hereinafter described in detail, is mounted on framework 16 and a rotatable drive shaft 70 thereof is provided with a drive gear 72 which meshes with a gear 74 on a shaft 76 of feed roll ers 32.

A scanner 80 is mounted on framework 16 a predetermined distance ahead of the

cutting blades

34 and 36. Scanner 80, preferably of the diffused reflection of light type, comprises a light source 82, a lens 84 which focuses the light at a point 86 in the path of the register marks on the web, as FIGS. 1 and 4 show, and a pair of

photoelectric cells

88 and 90 which are also focused on point 86. Scanner 80 is responsive only to the leading edge of each register mark and produces a single sharp electrical pulse for each register mark which is suitably amplified and utilized as hereinafter described. If preferred, however, other types of scanners could be employed.

CONTROL SYSTEM GENERALLY Referring to FIG. 1, it is seen that a control system (shown schematically in FIG. 1 and in detail in FIG. comprises scanner 80, timing or selector switch 68, correction motor 66 on transmission 60, a comparator circuit 92, comprising a thyratron circuit 94 and a timedelay circuit 96 for comparing output signals from scanner 80 and selector switch 68 to determine if correction motor 66 is to be energized, a motor-reversing circuit 98 operable in response to control circuit 92 to effect operation of correction motor 66, and a source of power 100 and a power supply circuit 102 for providing operating power to the several elements in the control system, as hereinafter described in connection with FIG. 110.

TIMING SWITCH Timing or selector switch 68 shown in FIGS. 4 through 9 of the drawings comprises a supporting structure having a back plate 104, a front plate 106, and four studs 108 for securing the plates together in spaced-apart relationship. Back plate 104 is provided with suitable flanges 110 for rigidly securing switch 69 to the supporting framework 16 of the cutting machine. Back plate 104 carries a bearing 112, shown in FIG. 6, for supporting one end of rotatable switch shaft 70 which is adapted to be driven, as hereinbefore explained, through suitable gears 72 and 74 by feed roll 32. The other end of switch shaft 70 is supported on a bearing 1114i hereinafter described.

First and second adjacent circular discs 116 and l 18, made of ferromagnetic material such as steel, are mounted on switch shaft 70 for rotation therewith. Each disc is provided with set screw means 120 on its hub to permit mounting and angular adjustment of the disc with respect to switch shaft 70. The

discs

116 and 118 are provided with notches or

cutouts

122 and 124, respectively, on their peripheries for actuating

magnetic pickup devices

126 and 128, respectively, located in proximity to the discs.

Each

magnetic pickup device

126 and 128 is understood, for example, to comprise a small magnet and a coil solidly encapsulated within a rugged stainless steel shell. Each magnetic pickup generates a voltage output or electrical pulse when ferro-magnetic material enters the magnetic field surrounding a pole piece at the sensing end of the pickup with sufficient speed. More specifically, the dynamic discontinuity provided by the notch or cutout in each disc as it enters the magnetic field around its associated magnetic pickup device produces an electric voltage or pulse. Such magnetic pickups are known in the art and the present invention em ploys a type designated Model 4947 manufactured by Automation Engineering Co., Inc, Mequon, Wisconsin, and shown in that companys bulletin MPB-269. The pulses from the

magnetic pickup devices

126 and 128 are used to actuate relays 2'7 2 and 274, hereinafter described. Each

relay

272 and 274 has a delayed break, i.e., its contacts are adjustable to close and stay closed for a predetermined interval of time, on the order of 0.05 to 1 seconds, depending on the time interval selected. Such a relay is known and is described in bulletin MP-969 of Electro Products Laboratories, Inc, Chicago, Illinois.

Magnetic pickup device 128 is supported in proximity to disc 118 by means of an adjustable yoke 134 which comprises an arm 136 which is rigidly secured to the inner end of a cylindrical sleeve 1138 surrounding but unattached to switch shaft 70. The outer end of sleeve 138 extends through front plate 166 of the switch and has a combined adjustment knob 114W) and dial plate 142 rigidly secured to the sleeve. Knob 1140 is supported by bearing 1 14 on the outer end of switch shaft which allows for relative movement between the knob and the switch shaft.

Magnetic pickup device 126 is supported in proximity to disc 116 by means of an adjustable yoke 144 which comprises an arm 146 which is rigidly secured to the inner end of a cylindrical sleeve 148 surrounding but unattached to sleeve 138 of yoke 134 hereinbefore described. The outer end of sleeve 148 extends through front plate 106 of the switch and has a combined adjustment knob and dial plate 150 rigidly secured thereto. Dial plate 142 is recessed within dial plate 150 but is relatively movable with respect thereto. More specifically, locking device 152 comprises a head 156, a collar I57, and a threaded shank 158 which engages a threaded opening 160 in dial plate I56. When locking device 152 is tightened, collar 157 bears against both dial plates i142 and 150 and prevents relative movement between the dial plates and their associated

yokes

134 and 144, respectively. Locking device I54 comprises a head 162, a collar 164 and a threaded shank 166 which engages a threaded opening in front plate 106. When locking device 156 is tightened, collar I64 bears against dial plate 150 and relative movement between dial plate 150 and front plate W6 is prevented.

'As FIGS. 41, 6, 7 and 9 show, a cutting adjustment I gear 170 is rigidly secured to sleeve 148 of outer yoke 148 by a set screw I72 and is rotatable by means of a cutting adjustment knob 174i and gear 1176 on front plate 106 of the switch to effect simultaneous rotational movement of both yokes 134 and M41 (when they are locked together by locking device 152) to make timing adjustments in the registration of web It) with

cutting blades

34 and 36. Referring to FIG. 5, counterclockwise rotation of both cutting yokes I34 and 144 by means of adjusting knob 174 effects an advance" registration adjustment and clockwise rotation effects a retard adjustment.

CONTROL SYSTEM IN DETAIL FIG. 10 is a circuit diagram of the control system in accordance with the invention. Generally considered, the control system comprises a power source 100, a power-supply circuit 102, a scanner and pulse amplifier circuit 180 including scanner 80, a selector switch circuit 182 including selector switch 68, a comparator circuit 92 including thyratron circuit 94 and time-delay circuit 96, and motor-reversing circuit 98 including correction motor 66.

Power source 100 supplies electrical power such as 110 volt, 60 cycle alternating current to two

supply lines

184 and 186. Power supply circuit 102 comprises a power transformer 1 having a primary winding 188a and three secondary windings 188b, 188c and 188d. An on-off switch 190 is in circuit between power line 184 and primary winding 188a of transformer 188. Power supply circuit 102 further comprises a full-wave rectifier tube 192 to which the

secondary windings

188b, 188C and 188d are connected, thereby providing a regulated DC voltage to control system components and circuits, as hereinafter appears.

Scanner and pulse-amplifier circuit 180 comprises light source 82,

photoelectric cells

88 and 90 which are connected in parallel, and an amplifier tube 194 which amplifies a pulse received from the photoelectric tubes when the light beam from light source 82 is interrupted by register mark 14 on web 10. Heater 1940 of tube 194 is connected across secondary winding 188d of power transformer 188. Cathode 194b of tube 194 is connected to ground and plate 194c is connected to power supply circuit 102.

Biasing grids

194d and 194e are connected to the cathode and plate, respectively, in tube 194. Control grid 194f of tube 194 is connected through a capacitor 196 to the cathodes 198 of

photoelectric cells

88 and 90. The amplified register mark pulse is transmitted through a conductor 200 to comparator circuit 92, as hereinafter described.

Comparator circuit 92 includes thyratron circuit 94 and time-delay circuit 96. Thyratron circuit 94 comprises two

thyratron tubes

202 and 204 which are understood to be grounded and ungrounded alternately by selector switch circuit 182, as hereinafter described. Thyratron tube 202 commprises a heater element 202a which is connected across secondary winding 188d of power transformer 188. The cathode 202b of tube 202 is connected to power supply circuit 102. The plate 202s of tube 202 is connected through a resistor 205 to one side of the operating coil 206a of a motorreversing relay 206. The other side of coil 206a is com nected through normally-open contacts 208a of a timedelay relay 208 to power supply circuit 102. A capacitor 210 is connected across relay coil 206a. The biasing grid 202d of tube 202 is connected to power supply circuit 102. A biasing or firing grid 202e of tube 202 is connected to a sensitivity-control rheostat 210 through a conductor 212. Rheostat 210 is connected through

resistors

214 and 216 to conductor 200 which supplies the amplified register mark pulse. As hereinafter explained, presentation of a register mark pulse signal to control grid 202e of tube 202 can effect firing of the thyratron only in the event that the thyratron is not in ungrounded condition as hereinafter explained. More specifically, control grid 202e of tube 202 is periodically grounded by timing switch circuit 182 and is, therefore, unable to effect firing of tube 202.

Thyratron tube 204 comprises a heater element 204a which is connected across secondary winding 188d of power transformer 188. The cathode 20411 of tube 204 is connected to power supply circuit 102. The plate 204: of tube 204 is connected through a resistor 218 to one side of the operating coil 220a of a motorreversing relay 220. The other side of coil 220a is connected through normally open contacts 208a of a timedelay relay 208 to power supply circuit 102. A capacitor 222 is connected across relay coil 220a. The biasing grid 204d of tube 204 is connected to power supply circuit 102. A biasing or firing grid 204e of tube 204 is connected to a sensitivity-control rheostat 226 through a conductor 224. Rheostat 226 is connected through

resistors

228 and 230 to conductor 200 which supplies the amplified register mark pulse. As hereinafter explained, presentation of a register mark pulse signal to control grid 204e of tube 204 can effect firing of the thyratron only in the event that the thyratron is not in ungrounded condition. More specifically, control grid 204e of tube 204 is periodically grounded by timing switch circuit 182 and is, therefore, unable to effect firing of tube 204.

If

thyratron tube

202 or 204 is tired, the tube is held in firing condition for a predetermined time interval by time-delay circuit 96 so that

relay

206 or 220 respectively may be energized for a length of time necessary to effect energization of correction motor 66. Timedelay circuit 96 comprises a multi-vibrator type electron tube 232, a time-delay relay 208 which comprises normally open relay contacts 208a and a relay coil 208b, and a potentiometer 234 for adjusting the length of the time delay. Heater element 232a of tube 232 is connected across secondary winding 188d of power transformer 188. Relay coil 208b of time-delay relay 208 is connected between plate 232b of tube 232 and power supply circuit 102. The cathode 2320 of tube 232 is also connected to power supply circuit 102. The control grid 232d of tube 232 is connected to potentiometer 234. A resistor 236 is connected across con tacts 208a of time-delay relay 208. The other plate 232e of tube 232 is connected to a pair of balancing

potentiometers

240 and 242 which, in turn, are connected to the sensitivity controls 210 and 226, respectively.

Motor reversing relays

206 and 220 comprise relay coils 206a and 220a, hereinbefore described, and sets of forward and reverse

relay contacts

206b and 220b, respectively. These sets of relay contacts are located in motor reversing circuit 98, shown in FIG. 10. The set of forward relay contacts 206k comprise a pair of stationary upper contacts 206a and 206d; a pair of stationary lower contacts 206e and 206]"; and a pair of movable contacts 206g and 206k operated by relay coil 206a. The set of reverse relay contacts 220b comprise a pair of stationary upper contacts 22% and 220d; a pair of stationary

lower contacts

220e and 220f; and a pair of movable contacts 220g and 220k operated by relay coil 220a. ln motor-reversing circuit 98, the sets of

relay contacts

206b and 220b and the

leads

250, 252, 254 and 256 of motor 66 are interconnected as follows to effect forward and reverse rotation of the motor when the relays are operated.

FIG. 10 shows both motor-reversing

relays

206 and 220 in contact open position whereby motor 66 is deenergized. When coil 2060 of forward relay 206 is energized to rotate motor 66 in the forward direction (for example, to speed up meter roller 26), movable con tacts 206g and 206h of relay 206 move from the position shown in FIG. 10 to a position wherein they engage the lower stationary contacts 206e and 206]",

respectively. In this condition, motor lead 252 is connected directly to line 186. Motor lead 254 is connected to line 184 through contact 2200, 220g, conductor 256, contact 206k, contact 206 conductor 266, and contact 226a. Motor lead 250 and motor lead 256 are connected in series with each other through contact 21162, 266g, 220k and 220d. Motor 66 is thus connected and energized for rotation in the forward direction to speed up meter roller 26 as long as relay contacts 20612 are closed. When relay contacts 266b open, the movable contacts return to the position shown in FIG. 16 and motor 66 stops.

When coil 220a of reverse relay 220 is energized to rotate motor 66 in the reverse direction (for example, to slow down meter roller 26), movable contacts 220g and 226k of relay 220 move from the position shown in FIG. 16 to a position wherein they engage lower stationary contacts 22% and 220 respectively. In this condition, motor lead 252 is connected to line 186. Motor lead 256 is connected to line 184 through contact 266d, 266k, conductor 256, contact 220g, and contact 2262.

Motor conductors

250 and 254 are connected in series with each other through contact 220f, contact 221th, contact 206g, and contact 206c. Motor 66 is thus connected and energized for rotation in the reverse direction to slow down meter roller 26 as long as relay contacts 22Gb are closed. When relay contacts 22612 are open, the movable contacts 220g and 220k return to the position shown in FIG. 10 and motor 66 stops.

The forward and reverse relay contacts 206k and 22% are usually operated in response to energization of the relay coils 206a and 220a, respectively, which are controlled by the thyratron tubes 202 and 2114, respectively. However, it is to be understood that forward and reverse relay contacts 2116b and 2211b can be operated to effect operation of motor 66 as hereinbefore described by normally open inching switches 264 and 266, respectively, directly from power source 100 or by additional normally open inching switches 268 and 2711, respectively, in selector switch circuit 182.

Selector switch circuit 182 comprises timing or selector switch 66 which has two

magnetic pickups

126 and 126, hereinbefore described. The

magnetic pickups

126 and 126 are connected to magnetic pickup relays 272 and 276, respectively. The normally open contacts 272a of relay 272 have one side connected to ground and the other side connected through a conductor 276 to sensitivity control 210 through resistor 214. The normally open contacts 274a of relay 274 have one side connected to ground and the other side connected through a conductor 278 to sensitivity control 226 through resistor 228.

SCANNING AREA Timing or selector switch 68 operates to define a time interval or scanning interval which, for purposes of discussion, may be considered as an imaginary scanning area 15, shown in FIG. 3, which is divided into three zones, namely, a retard zone 17, an in-register zone 19, and an advance zone 21. Scanning area needs to be adjustable in several ways. First, the width of in-register zone 19 should be slightly wider that the width of a particular register mark 14. Second, the entire width of scanner area 15 should be such that it will not superimpose itself on any portion of a printed design 12, when titted between two adjacent designs, as

FIG. 3 shows. in practice, assuming a one-to-one ratio between rotation of timer switch 66 and rotation of feeder roll 32 and one cycle of operation of cutter 341, the width of advance zone 21 is usually equivalent to about 30 of angular distance on feed roll 32. Similarly, the width of retard zone 17 of scanner area is usually equal to about 30 degrees of angular distance on feed roller 32. In such a relationship, the width of advance zone 21 is equal to one-twelfth the cut-off length of each design and the width of retard zone 17 equal to one-twelfth the cut-off length of one design. For example, if a design is to be cut every 12 inches on web 111, advance zone 21 would equal 1 inch and retard zone 17 would also equal 1 inch. The width of advance zone 21 is determined by the time setting of relay 272 and the width of retard zone 17 is determined by the time setting of relay 2741. Advance zone 21 is adjustable toward and away from retard zone 17 so as to permit a desired width of in-register zone 19. This adjustment is accomplished by angularly moving

magnetic pickups

126 and 126 so as to enlarge or diminish angle alpha between them. Scanning area 15 can also be shifted toward or away from point 86 shown in FIG 3. Such shifting is ac complished by rotating

magnetic pickups

126 and 126 simultaneously in either the clockwise or counterclockwise direction with respect to FIG. 5. As hereinafter explained in detail, scanning area 15 can be shifted so that either advance zone 21, in-register zone 19, or retard zone 17 appear to overlie point 86. If in-register zone 19 appears to overlie point 86, the register mark pulse will be in register and no correction of meter roll 26 will be initiated by motor 66. If scanning area 15 is shifted so that advance zone 21 appears to overlie point 86, the register mark pulse comes up late and an advance signal is sent to correction motor 66 to speed up meter roll 26. If scanning area 15 is shifted so that retard zone 17 appears to overlie point 86, the register mark pulse comes too soon and a retard signal is sent to correction motor 66 to slow down meter roll 26 to bring the next register mark to correct position. Normally, scanning area 15 is adjusted so that in-register zone 19 appears to overlie point 86. In this situation, correct cutting will occur. Misregistration caused by the register mark pulse occurring too soon or too late with respect to in-register zone 19 defined by timing switch 68 results in an appropriate correction signal being sent to correction motor 66.

Advance zone 21 is adjustable away from retard zone 17 so as to permit a change in the size of in-register zone 19, so that the width of the in-register zone is slightly larger than the width of a register mark. Changes in the width of in-register zone 19 are accomplished by moving the

magnetic pickups

126 and 126 on timing switch 68 with respect to each other. For example, referring to FIGS. 5 and 111, if angle alpha is decreased, the width of in-register zone 1'9 in scanning area 15 will be expanded. Conversely, if angle alpha is increased, the width of in-registerzone 1% will decrease. These adjustments are made as follows. Refer ring to P16. 4, both locks 152 and 151 are unlocked. The position of magnetic pickup 126 is adjusted by turning dial 151) so that the beginning of the scanning area can be adjusted at a predetermined point in time with respect to cutter 34. Then, locking device 152 is locked so that dial cannot be moved. Then, the. position of magnetic pickup 128 with respect to magnetic pickup 126 is adjusted by turning dial 1411). Then locking device 154 is locked so that dial 142 cannot be moved. The adjustments to switch 68 thus far described merely define the total width of scanning area and, in particular, the width of in-register zone 19.

It is apparent from the construction of switch 68 that the adjustments described hereinbefore can be carried out while the web-cutting apparatus and switch 68 are in operation.

In a situation where it is desired to shift the entire scanning area 15 either forward or backward with respect to a register mark 14, assuming that the size of the in-register area has been selected and switch 68 adjusted accordingly, it is necessary to unlock locking de- -vice 154. Then cutter adjustment knob 174 is rotated in the desired direction and for a desired amount so as to move both

yokes

134 and 144 simultaneously for the desired distance in the desired direction. This movement of both yokes simultaneously has the effect of shifting the scanning area. In practice, it causes motor 66 to be energized sooner or later to effect advance and retard corrections with respect to a point in the operation of cutting blade 134.

OPERATION The web cutting apparatus and control means in accordance with the invention operate as follows. Assume that the web-cutting apparatus is in operation and that web 10 is passing under scanner head 80. Further assume that switch 190 is closed and that all control circuits are receiving operating power. Also assume that selector switch 68 is rotating in the direction of arrow 11 and is in synchronism with the reciprocating operation of cutter blade 34 in a one-to-one ratio. Finally assume that notch 122 in the larger disc 116 of timing switch 68 has just passed magnetic pickup 126 and that contacts 272a of pickup relay 272 are closed. This closure of relay contacts 272a marks the start of the scanning interval. The length of time contacts 272a remain closed defines the width of retard zone 17 of scanning area 15. With contacts 272a closed, control grid 202e of thyratron tube 202 is grounded through conductor 212, sensitivity control 210, conductor 276, and contacts 272a. However, since contact 274a of pickup relay 274 are open, the control grid 2042 of thyratron tube 204 is ungrounded.

Now assume that a register mark 14 interrupts the light beam from light source 82 to

photoelectric cells

88 and 90 as web 10 passes under scanner head 80. Further assume that this interruption occurs while pickup relay 272 is closed, i.e., that the register mark pulse occurs in retard zone 17 of scanning area 15. Interruption of the light beam causes

photoelectric cells

88 and 90 to produce a register mark pulse in conductor 196 which is transmitted to amplifier tube 194 and amplified therein. The amplified register pulse is transmitted through conductor 200 and through both sensitivity controls 210 and 226 and through

conductors

212 and 224, respectively, to the control grids 202a and 204e, respectively, of the

thyratron control tubes

202 and 204, respectively. Since conrol grid 202a of tube 202 is grounded, the presentation of the amplified register mark pulse to its control grid 202e is ineffective to fire tube 202. However, since tube 204 is ungrounded, appearance of the amplified register mark pulse at its control grid 204:: causes tube 204 to fire. When tube 204 fires, relay coil 220a of motor relay 220 is energized and contacts 220a of motor reversing relay 220 close to energize motor 66 for rotation in the reverse (retard) direction. Tube 204 is held on firing condition and relay 220 remains energized for a time interval determined by the length of time timing relay contacts 208a of timing circuit 96 remain closed. When this in terval expires, timing relay contacts 208a open to deenergize relay coil 220a of motor relay 220. As

discs

116 and 118 of timing switch 68 continue to kotate,

contacts 272a of pickup relay 272 reopen and tube 202 is no longer grounded.

Now assume that interruption of the light beam occurs while pick-up

relays

272 and 274 are both open, i.e., in the in register zone of scanning area. As is apparent, the amplified register mark pulse is then presented to control

grids

202e, 204e of

tubes

202 and 204 simultaneously, but since relay contacts 208a of timing relay 208 are open, neither coil 204a nor coil 220a of motor relays 206 and 220 will be energized and no correction signal will be presented to motor 66. In this situation, the register mark pulse appears in the inregister zone of scanning area.

As

discs

116 and 118 of timing switch 68 continue to rotate, a point is reached where slot 124 of inner disc 118 passes magnetic pickup 128, thereby causing pickup relay 274 to be energized and its contacts 27411 to close for a predetermined interval of time. The length of time contacts 274a remain closed defines the width of advance zone 19 of scanning area 15. With contacts 2740 closed, tube 204 is grounded because its control grid 204e is connected to ground through conductor 224, sensitivity control 226, resistor 228, conductor 278 and contacts 274a.

Now assume that the interruption of the light beam occurs while pickup relay 274 is closed, i.e., in the advance zone of scanning interval. Since the amplified register mark pulse is presented to control grid 204e of tube 204 while tube 204 is grounded, tube 204 will not fire. However, the register mark pulse is simultaneously presented to control grid 2022 of tube 202 while tube 202 is ungroundecl and tube 202 fires. Relay coil 206a of motor relay 206 is thereby energized, its contacts 206e close and motor 66 is energized for rotation in the forward (advance) direction to increase the speed of meter roll 26. Tube 202 is held in firing condition and relay 206 remains energized for a time interval determined by the length of time timing relay contacts 208a of timing circuit 96 remain closed. When this time interval expires, timing relay contacts 208a open to deenergize relay coil 206a of motor relay 206.

I claim:

1. Web processing apparatus for a web containing repeated designs and corresponding register marks comprising:

a processing device operable to perform a process on each design, feed means for repeatedly feeding a predetermined length of web to said processing device, and

metering means for supplying a predetermined length of web to said feed means, said metering means normally operating at a constant speed when said designs are in registry with said processing device, and

control means for said web processing apparatus for maintaining the designs in registry with said processing device, said control means comprising:

correction means operable to momentarily change the speed of said metering means to supply a different length of web to said feed means,

scanning means in fixed location with respect to said processing device for sensing passage of a register mark and for providing a register mark pulse in response thereto,

a selector switch responsive to the position of said processing device for providing output signals for each cycle of operation of said processing device definitive of a scanning interval during which a process will be performed on a design by said processing device, said scanning interval comprising advance, retard and in-register zones, and

a control circuit for comparing the relationship of a register mark pulse to a scanning interval and for providing a correction signal to said correction means in the event said register mark pulse occurs at a time during said scanning interval other than in the in-register zone; said selector switch comprising:

a pair of pulse'producing means for producing a pair of output pulses spaced apart in time which define the limits of said scanning interval for a cycle of operation of said processing device,

first adjustable means for selectively changing the length of the spacing between said pulse producing means to change the time interval between said pair of pulses to change the width of said scanning interval, and

second adjustable means for selectively changing the position of at least one of said pulse producing means to shift one end of the time interval with respect to the cycle of operation of the processing device so as to shift the scanning interval with respect to the processing device.

2. The combination according to claim 1 wherein said pulse producing means comprises a support, a pair of pickup devices mounted on said support, and rotatable means synchronized with the cycle of operation of said processing device for causing said pickup devices to produce said output pulses.

3. The combination according to claim 2 wherein said first adjustable means in said selector switch comprises means for changing the angular distance between said pair of pickup devices.

4. The combination according to claim 3 wherein said second adjustable means in said selector switch comprises means for changing the: relative angular relationship between said pair of pickup devices and said rotatable means.

5. The combination according to claim 4 including a shaft rotatable on said support and on which said rotatable means are fixed, and wherein said first and second adjustable means comprise a pair of movable yokes mounted on said support, each yoke supporting one of said pickup devices.

6. The combination according to claim 5 wherein said rotatable means comprise a pair of discs mounted on said shaft, each disc being associated with one pickup device and having means thereon for actuating its associated pickup device.

7. The combination according to claim 6 wherein said pickup devices are magnetic pickup devices and wherein the means on each disc for actuating an associated pickup device is a discontinuity in the disc.

Claims

1. Web processing apparatus for a web containing repeated designs and corresponding register marks comprising: a processing device operable to perform a process on each design, feed means for repeatedly feeding a predetermined length of web to said processing device, and metering means for supplying a predetermined length of web to said feed means, said metering means normally operating at a constant speed when said designs are in registry with said processing device, and control means for said web processing apparatus for maintaining the designs in registry with said processing device, said control means comprising: correction means operable to momentarily change the speed of said metering means to supply a different length of web to said feed means, scanning means in fixed location with respect to said processing device for sensing passage of a register mark and for providing a register mark pulse in response thereto, a selector switch responsive to thE position of said processing device for providing output signals for each cycle of operation of said processing device definitive of a scanning interval during which a process will be performed on a design by said processing device, said scanning interval comprising advance, retard and in-register zones, and a control circuit for comparing the relationship of a register mark pulse to a scanning interval and for providing a correction signal to said correction means in the event said register mark pulse occurs at a time during said scanning interval other than in the in-register zone; said selector switch comprising: a pair of pulse producing means for producing a pair of output pulses spaced apart in time which define the limits of said scanning interval for a cycle of operation of said processing device, first adjustable means for selectively changing the length of the spacing between said pulse producing means to change the time interval between said pair of pulses to change the width of said scanning interval, and second adjustable means for selectively changing the position of at least one of said pulse producing means to shift one end of the time interval with respect to the cycle of operation of the processing device so as to shift the scanning interval with respect to the processing device.

4. The combination according to claim 3 wherein said second adjustable means in said selector switch comprises means for changing the relative angular relationship between said pair of pickup devices and said rotatable means.