US3280737A

US3280737A - Web registering system for multi-unit presses

Info

Publication number: US3280737A
Application number: US287622A
Authority: US
Inventors: William F Huck
Original assignee: Individual
Current assignee: Individual
Priority date: 1963-06-13
Filing date: 1963-06-13
Publication date: 1966-10-25
Anticipated expiration: 1983-10-25
Also published as: DE1474227A1

Description

Oct. 25, 1966 w. F. HUCK 3,280,737

WEB REGISTERING SYSTEM FOR MULTI-UNIT PRESSES Filed June L3, 1963 4 Sheets-Sheet l INVENTOR.

WILLIAM HUC BY T TOR NE y WEB REGISTERING SYSTEM FOR MULTI-UNIT PRESSES Filed June 13, 1965 W. F. HUCK Oct. 25, 1966 4 Sheets$heet 2 NJ 3 3. O2 r we W NE vfl \31 d m 21 8. A: w: p

m 08 Ag 2 km: @725 30m 205 a w:

0 mm wn INVENTOR. WILLIAM F. HUC

OR NE Y Oct. 25, 1966 w. F. HUCK 3,280,737

WEB REGISTERING SYSTEM FOR MUL'II'UNIT PRESSES Filed June 13, 1965 4 Sheets-Sheet 5 INVENTOR.

58b WILLIAM F. HUCK BYQ ML. M

TTORNE Y Oct. 25, 1966 w. F. HUCK 3,280,737

WEB REGISTERING SYSTEM FOR MULTI"UNIT PRESSES Filed June L3, 1963 4 Sheets-Sheet 4 INVENTOR. W l LLIAM F. H UC K ORNEY United States Patent 3,280,737 WEB REGISTERING SYSTEM FOR MULTI-UNIT PRESSES William F. Huck, 81 Greenway Terrace, Forest Hills, N.Y. Filed June 13, 1963, Ser. No. 287,622 18 Claims. (Cl. 101181) This invention relates to web processing machines and more particularly to apparatus for controlling the register of the web on a multi-unit web processing machine such, for example, as a multi-color rotary gravure printing press.

It is of course important to the proper operation of such machines that the printing or other action of each unit take place at locations on the web kept accurately in register with the locations acted upon by every other unit. Off-register printing operations and problems of maintaining required conditions of register are, however, continuing causes of wastes of printed matter and of delays and limitations upon production speeds in the operation of web processing machines. This is especially the case in respect to machines, such as multi-color gravure printing presses, by which a plurality of operations are required to be performed in register on a running web at widely spaced stations of each machine.

Although it is theoretically possible to adjust several processing units so that the operations they perform will be in register, in practice register errors occur as a result of one or more of a variety of variable factors. Variations of the thickness, the moisture content, the temperature or the strength of the paper or other web material being processed tend to produce register errors. So also will variations of press room atmospheric conditions, press operating speeds, web tension and other conditions affecting the web on the machine or the dimensions or constancy of action of the web engaging rotary units of the machine.

It is known that register errors may be corrected by selectively varying the effective length of the web between a processing unit where a register error has been detested and the preceding unit. This length variation may be accomplished by displacing or by varying the speed of a roller or a web propelling couple acting upon the web travelling to the farther unit. Where the processing units positively grip and propel the web, as do the cylinders at each printing station of a multi-color gravure printing press, the length of the web passing between units may be varied by varying the rotational speed of one set of cylinders relative to that of another set. In the use of such techniques, the tension or stretch of the web travelling between the two processing units is varied, to the end that the web will gradually move back into register with the unit where register is lacking.

It will be understood that the rapidity of the register correction in such cases depends upon the magnitude of the change of the effective web length between the two units and the distance and the steps of friction and tension increase in the web path between the units, as well as the web speed. A flexible web, such as of paper, exhibits qualities of an elastic band as it is passed through the press. If it is out of register at one unit by a few thousandths of an inch and there is a large distance occupied by many web contacting elements between units, as in the case of a multi-color gravure press where the web after each impression may pass through a drying and cooling system, etc., so as to travel a distance of 30 ft. or more between printing units, an effective length change of a few thousandths of an inch in .the web either will not correct the register error or will require too long a time to do so.

3,280,737 Patented Oct. 25, 1966 For this reason, it is necessary to introduce a substantially greater change in the effective web length between the units, which causes over-correction after a period of continued web travel and thus necessitates further action to remedy the overcorrection. In practice, therefore, the correction devices operate with continual hunting back and forth, alternately increasing and decreasing web tension and thus keeping the web hovering close to the required registered position.

The longer or the more obstructed is the web path between the successive control points or processing units, the greater is the elastic play of the intervening web length and the larger the amount of correction and overcorrection required for a given register error.

It will also be evident that varying the web length between two processing units in order to correct a register error at the farther unit tends to disturb the register of the web at the near unit and, to a lesser extent, at all preceding units, since the tension eifects of web length varation at one location in the machine tend to pass through the entire machine. This problem is of course aggravated when the correction of a small error requires a comparatively large change in the effective web length.

It is an object of the present invention to provide in a multi-unit web processing machine a system of apparatus which will quickly and positively correct detected errors in the register of the web.

A further object of the invention is to provide a multiunrt web processing machine by which a web imprinted or otherwise processed at one unit may be kept in register with the succeeding unit or units without hunting.

Another object is to provide in such a machine apparatus which will correct detected errors in register of the web to one processing unit without disturbing the register of the web to other processing units.

A further object is to provide a register correction system or apparatus of the above character which will hold the register of the web at any speed of operation of the machine or while the machine is being accelerated or decelerated.

Another object is to provide in such a machine apparatus which will hold the register of the web to the various processing units during stoppage of the machine.

Still another object is to provide such apparatus whereby coacting cylinders at the processing units will continue to be in register with the web when they are reengaged after being separated for slow rotation during stoppage periods.

A further object is to provide a system of apparatus of the character above mentioned which will serve effectively for controlling the tension of the web travelling to a processing unit when the web moving thereto is unprinted or otherwise unmarked and, therefore, no registering of the web thereto is required.

A further object is to provide, in a web processing machine where the web passing from one processing unit to the next is guided over a series of idler or free running rollers, such as oven rollers, cooling rollers or the like, engaged and driven by the web, apparatus which will act upon abrupt stoppage of the machine to free these rollers from constraint by the web, and thereby prevent these rollers from damaging the web.

It is a still further object of the invention to provide a register control system of the type mentioned which will serve effectively for registering a web that is inverted by being passed over turn bars between successive processing units and that has a relatively high and/or an irregular tension level built up in it when it reaches or as it passes over the turn bars.

According to one aspect of the present invention, the web travelling through an extended path between successive processing units is drivingly engaged by driven roller means disposed at a point in the web path ahead of, and preferably immediately adjacent to, the farther or second of the two units, and upon the detection of a register error at the second unit these roller means are acted upon so as to vary transiently the speed of the portion of the web enaged by them relative to the speed of the portion of the web engaged by the second processing unit and thereby to vary the stretch of the web lead extending from the roller means to the second unit in the sense to correct the register error. This transient variation of the relative speeds of the web portions is effected most advantageously by simultaneously displacing and varying the rotational speed of the roller means, so that a dual corrective effect is obtained in said web lead, although either displacement or a rotational speed variation will give the transient variation to some extent. Acting in cooperation with the driven roller means is a floating roller which is yieldably biased against the web lead approaching the driven roller means so that the tension and thereby the stretch of the web lead between the first unit and the driven roller means is maintained substantially constant irrespective of the register correcting action of the latter. In this manner, detected register errors at the second unit are quickly and positively corrected without objectionable hunting of the register control devices and without disturbing the register of the web to the first unit.

According to another aspect of the invention, the proccessing units each comprise coacting cylinders which cyclically imprint the web and are separable during stoppage periods of the machine to free the web, or to be kept in slow rotation without acting upon the web; and the roller means comprise driven rollers engaging the web in non-slipping relation thereto so that when the cylinders are separated during stoppage of the machine the driven rollers will continue to hold the web in place relative to the printing position of the cylinders. Since the driven rollers are driven in synchronism with the processing cylinders from a common rotary power source, a clutch is provided in the driving train to the driven rollers so that these rollers may be disconnected from the power source, and yet the cylinders kept connected with it, when the processing cylinders are separated.

According to another aspect of the invention, means are provided which act upon stoppage of the machine to latch the floating tension control roller in the working position which it then occupies so that it will be prevented from displacing the web when the web becomes slack due to separation of the cylinders of the processing unit preceding the floating roller, whereby to maintain the established register between the web and this preceding unit.

According to yet another aspect of the invention, means are provided which act upon stoppage of the press to clamp the web firmly at spaced locations therealong so that inequalities of web tension which may exist along the various leads of the web when the machine is stopped will be prevented from causing rotation of the driven rollers when the latter are declutched from the machine drive.

According to another aspect of the invention, which is important for installations where the web is guided over a series of rollers, such as oven rollers, cooling rollers, or the like, while passing from one processing unit to the next such unit, the web guiding rollers are constituted as idler or free running rollers and means are provided which act upon a sudden or emergency stoppage of the machine to cut ofi or at least substantially reduce the biasing force on the floating tension roller, whereby to reduce the web tension so that the idler rollers are freed from constraint by the web and allowed to coast or run freely to a stop without causing damage to the web by their continuing momentum.

According to a further aspect of the invention, means are provided which act to stop the processing cylinders at the same angular position each time a signal to stop the machine is given, so that after being rotated slowly during a period of press stoppage the cylinders are halted at the same angular positions they occupied when the machine was initially stopped. Thus, when they are reengaged with the web they will continue to be in register with it.

Where Web being pocessed is inverted between processing units, as by passing it over turn bars, and a relatively high and/ or irregular tension level is likely to build up in the web ahead of the turn bars, the invention may be applied advantageously by providing a device ahead of the turn bars to maintain substantially constant tension in the web entering the turn bars and arranging the driven register control rollers beyond the turn bars to act upon a portion of the web leaving them. Any of several possible arrangements of apparatus set forth herein may be utilized to achieve the purposes of the invention under these conditions.

According to yet another aspect of the invention, a tension controlling apparatus is provided which includes driven rollers means drivingly engaging a lead of the web and a floating roller yieldably biased against the web lead to maintain the tension in the lead substantially constant. The floating roller has a limiting position to which it is movable under varying web conditions and means are provided which are responsive to movement of the roller to its limiting position to act upon the driven roller means so as to move this means and the web in the direction to free the floating roller and allow it to move away from its limiting position to resume control of the web tension.

The above mentioned and other objects, aspects and advantages of the invention will be further apparent from the following detailed description of preferred embodiments thereof and from the accompanying drawings in which:

FIG. 1 is a schematic view of a multi-unit web printing machine adapted for register control according to the pesent invention;

FIG. 2 is a view of a portion of the same machine;

FIG. 3 is a sectional View thereof taken on line 33 of FIG. 2;

FIG. 4 shows schematically a modified form of register control apparatus useful in the machine;

FIG. 5 shows schematically another modified form of such apparatus;

FIG. 5 is a diagrammatic view of an embodiment of the invention wherein the web passing between two rotary printing units is inverted by the action of turn bars;

FIG. 6 is a diagrammatic view of an embodiment of bodiment; and

FIG. 8 shows a modification of the embodiment of FIG. 7.

In the multi-color web printing press of FIG. 1, a web W is unwound from a rollstand RS, which preferably is an automatic splicing rollstand of the type disclosed in my copending US. Patent No. 3,103,320.

From the rollstand RS the web W travels over suitable guide rollers to a printing unit P-1 which applies patterns and register marks to the web, typically in yellow.

The web is then moved successively through printing units P-2, P-3, P-4 which typically print the web in red, blue and black, respectively. After leaving unit P-4, the web travels to a processing unit P-S which may take any of various forms. For example, it may be a perforating unit, a slitting unit, a cross-cutting unit, an embossing unit or a set of collating rollers associated with a folding unit.

If the Web W is preprinted, it may be threaded along an alternate path indicated in dash lines in FIG. 1, directly from the rollstand RS to the unit P-2.

If the web is to be printed on both sides, it may be printed on one side by the unit P-1 and thereafter guided along a path shown by the chain lines in FIG. 1 to a turn bar unit TB which turns the web over, so that it may be thereafter printed on its opposite side by the units P-2, P-3, and P4. A similar turn bar arrangement may of course be provided between any two of the printing units.

The printing units, as seen in FIG. 2 in respect to units P-1 and P-2, may each comprise an ink fountain system 10, shown only in diagram, contacting and applying printing ink to an engraved gravure cylinder 12 against which a rubber covered or equivalent nip roller 14 presses the web tightly under force provided by a steel back-up or impression cylinder 16.

The gravure cylinder 12 of each printing unit is driven from the main press drive shaft 20 which is driven from the main press motor M by belts 22 trained around a pulley 24 on the output shaft of the motor and a pulley 26 on the drive shaft. Each nip roller 14 is fri-ctionally driven by the coacting gravure cylinder. Motor M is controlled from a control panel 28 having a push button station 30. The station 30 includes a button 30a for servicing the press, threading the web etc., a button 30b for normal drive or operation of the press, a button 300 for emergency press stops, and a button 30d for normal press stops. Current is delivered to push button station 30 from main supply lines L1, L2, through an on-off switch 32.

After leaving a printing unit, such for example as the unit P-l in FIG. 2, the Web is guided through a drying oven 0 by a plurality of guide rollers 34. From the oven, the web is guided to free running cooling cylinders 36 around which the web is trained in serpentine fashion. From the cylinders 36 the web travels over guide rollers 38, 40 and 42, over a floating roller 44, thence in serpentine fashion around drive rollers 46 and 48, and then over guide roller 50 to the printing unit P-Z. A similarly constituted path of travel may be provided between units P-2 and P-3 and between units P-3 and P-4.

The drive rollers 46 and 48 form a part of a longitudinal register control device, indicated by the block R-2 in FIG. 1. As seen in FIG. 1, one such longitudinal register control device R-2, R-3, R4 or R-S is provided between each two successive printing units and between the last printing unit P-4 and the web processing station P-S. If the web is to be collated at P-S with other webs such, e.g., as the webs W-2, W-3 and W-4 shown in phantom lines in FIG. 1, then similar register control devices R-6, R-7, and R-8 are provided for these other webs and are driven in synchronism with the device R-S.

The device R-2 as seen in FIG. 2 includes a displaceable carriage 52 rotatably supporting the drive rollers 46 and 48. A V-belt pulley 54 is secure-d to an extension of the drive roller 48 and is driven by a V-belt 56 trained around a V-belt pulley 58 mounted on a fixed axis. The pulley 58 is driven by a drive shaft 18 driven from the main press drive shaft 20. The roller 48 is driven from the roller 46 by suitable gear means (not shown), so that when the motor M is active the rollers 46 and 48 are driven in opposite directions and in synchronism with the units P-1 and P-2 and cooperate with these units to propel the web along the extended path between these units.

The carriage 52 has a mounting arm securing it for pivotal reciprocating movement on a shaft 62 pivotally mounted in the press frame. An arm 64 is secured at one end to the shaft 62 and at its other end carries a pivotally mounted nut 66 which is engaged by a screw 68 coupled to the output shaft of a reversible electric motor 70 so that upon actuation of motor 70 the carriage 52 is pivoted about the axis of shaft 62 to move the drive rollers 46 and 48 toward or away from the printing unit P-2.

Pivotally mounted on the carriage 52 are arms 72 carrying pressure rollers 74 at their outer ends. Spring means (not shown) continuously hold the rollers 74 and thereby web W in non-slip driving contact with the drive rollers 46 and 48, so that movement of the rollers 46 and 48 toward or away from the unit P-2 moves the web portion engaged by these rollers toward or away from this unit.

It will be evident that such displacement of the driven rollers 46, 48 has the effect of transiently varying the speed of movement of the portion of the web engaged by these rollers, relative to the speed of the portion of the Web engaged by the unit P-2, and thus will vary the stretch of the web lead extending from the rollers to the unit P-2.

The belt contacting radius of the V-belt pulley 58 is variable in response to variations of the tension of V- belt 56. The pulley 58 may be, for example, of the type disclosed in my United States Patent No. 2,812,666. Tensioning rollers 76 carried on the free ends of arms 78 clamped to stub shafts 80 bear against the V-belt and are adjustable by adjustment of the arms 78 on the shafts 80 to vary the belt contacting radius of the pulley 58 so as to establish the desired initial ratio of the peripheral speed of the rollers 46 and 48 to the peripheral speed of the unit P-2.

It will be seen that the aforedescribed displacement of the rollers 46 and 48 toward or away from the unit P-2 in response to actuation of the motor 70 will vary the tension of the belt 56 and thereby vary the belt contacting radius of the pulley 58 and the speed of the belt 56, whereby to vary the rotational speed of the rollers 46 and 48 relative to that of the. printing unit. Specifically, movement of the rollers 46 and 48 toward unit P-2 increases the rotational speed of the rollers 46 and 48, and movement of the rollers 46 and 48 away from unit P-2 decreases their rotational speed. Thus, as these rollers are moved closer to the printing unit their peripheral speed and the speed of the web .portion propelled by them is increased relative to the speed of the web portion engaged by unit P-2, while the opposite effect is obtained when these rollers are moved farther away from the printing unit. That is, the effects of the bodily movement and the simultaneous speed variation of the rollers 46 and 48 are additive, so that there is a dual effect upon the stretch of the web lead extending from these rollers to the unit P-2.

Photoelectric scanning heads 82 and 84 are disposed at opposite sides of the variably stretched web lead between the carriage 52 and the proximate printing unit. These scanning heads may be of the type commercially available from the Specialty Control Department of the General Electric Co., Waynesboro, Virginia, as Item No. CR 7515P20 2G4. A scanning head of the identified type includes a light source directing a beam of light against the web and a photoelectric cell which measures the intensity of the light of the beam that is reflected by the web toward the cell.

- One of the scanning heads emits an electrical signal each time a register element, such, for example, as a register mark applied to the Web W by the printing unit P-l, passes a fixed point in the area scanned by the head. mark applied to the web W by the printing unit P-1, P-2, the head 82 emits the register signals. When the web leaving unit P-1 is passed through a turn bar unit TB so that the marks printed on the web P-l are on the upper side of the web approaching unit P-2, the head 84 emits the register signals.

The signals from

head

82 or 84 are compared with a series of electrical signals emanating from a photoelectric selector switch 86 which is driven from the gravure cylinder 12 of unit P-2 through a pulley 88, non-slip belt 89 and pulley 91. The switch 86 may be of the type commercially available from the Specialty Control Department of the General Electric Co., Waynesboro, Virginia, as Item No. CR 7515PI45G4.

The signals from

head

82 or 84 and those from switch 86 are fed to and compared by a control panel 90, which may be of the type commercially available from the Specialty Control Department of the General Electric Co., Waynesboro, Virginia, as Item Nos. 357515-CT A1. The control panel 90 is operative to generate an error signal in response to the detection of a lack of synchronization between the signals from the

head

82 or 84 and those from the switch 86, and these error signals, which are proportional in magnitude to the register error detected, are fed to the reversible motor 70 to rotate that motor in the direction and to the extent required to correct the detected error.

Specifically, if the signals from

head

82 or 84 lag behind those from switch 86, indicating that the register marks on the web W are lagging behind the required register position with respect to the gravure cylinder 12, motor 70 is rotated in the direction to pivot carriage 52 clockwise (as viewed in FIG. 2) about the axis of shaft 62, so that the rollers 46 and 48 are moved toward unit P-2 to displace the web portion engaged by them toward that unit andsimultaneously increase the rotational speed of the rollers and thus, by both of these actions, increase the relative linear speed of the web portion propelled by the rollers. As a result, the stretch of the relatively short Web lead between the rollers 46 and 48 and the cylinder 12 will be reduced to move the register marks on the web directly to their position of correct register with the cylinder.

If the signals from

head

82 or 84 are ahead of those from switch 86, indicating that the register marks on web W are ahead of the required register position with respect to the gravure cylinder 12, motor 70 is rotated in the direction to pivot the carriage 52 counterclockwise, thus displacing the rollers 46 and 48 and the web portion engaging them farther away from the cylinder and simultaneously and proportionally decreasing the rotational speed of the rollers so as to increase the stretch in the web lead between the rollers and the cylinder.

Since the register control device R-Z operates on and varies the stretch in only a relatively short lead of the web approaching the printing unit, the ratio of the resulting corrective movement of the individual marks on the web to the applied correcting displacement of the register device is considerably greater than in known register control systems, with the important results that the detected errors are corrected more quickly and more accurately than by the known systems, and with a smaller amount of corrective displacement and little or no hunting of the register device.

Further the corrective action obtained by variations of the relative speed of the rollers 46 and 48 has the important advantage of being effected at any speed of operation of the printing machine, so that the web may be held in register at high or low press speeds as well as when the press is undergoing acceleration or deceleration.

Any displacement or rotational speed variation of the rollers 46 and 48 of course tends also to vary the tension and thereby the stretch of the relatively long web lead extending from the preceding printing unit P-l to these rollers. Such a variation is prevented, however, by the floating tension control roller 44 of the device indicated at T-2 in FIG. 1, over which roller the web lead from unit P-1 passes as it approaches the driven rollers 46 and 48.

As seen in FIG. 2, the device at T-2 includes an arm 92 which may be one of a pair of arms pivotally mounted between their ends on a shaft 94 and rotatably carrying the floating roller 44 at one of their ends. The other end of arm 92 is secured to the piston of a fluid pressure cylinder 96 pivotally suspended from the frame of the press. A conduit 98 extends to cylinder 96 from a source of fluid under pressure (not shown), and a pressure regulator 100 is provided in the conduit 98 to adjust the fluid pressure acting against the piston of the cylinder. The magnitude of the fluid pressure is indicated by a pressure gauge 102 which may be calibrated in units of web tension to provide a continuous and easily readable indication of web tension.

The web W wraps around the roller 44 in a direction such that the pull of the tensioned web on this roller urges the roller downwardly with a force that is resisted by the pressure of the air acting on the piston of the cylinder 96, so that the magnitude of the tension in the web lead between the drive rollers 46 and 48 and unit P-1 is determined by the magnitude of the air pressure and is maintained at that value irrespective of web and roller displacements cause-d by bodily movements and variations in the rotational speed of the driven rollers 46 and 48.

The tension control device T-2 and the register control device R-2 thus act in conjunction to vary the tension and thereby the stretch of the relatively short lead of the web between the rollers 46 and 48 and the unit P-2 in the sense'and to the extent required for quick correction of detected errors in register of the successive printed patterns or other processed locations on the web with respect to the gravure cylinder 12, while maintaining the tension and thereby the stretch of the relatively long lead of the web between unit P-1 and device R-2 substantially constant so as not to disturb the register of the web to the unit P-1.

The non-slip engagement of the web by the rollers 46 and 48, in addition to confining the register corrective action to a relatively short web lead, also will serve to hold the web in its transient position relative to the gravure cylinder 'when the machine is stopped for any reason. This has the important result that when the machine is stopped for servicing and, as is customary, the nip roller 14 and impression cylinder 16 are raised out of contact with the web and gravure cylinder 12 to enable slOW rotation of the cylinder 12 through the ink fountain 10, the rollers 46 and 48 continue to hold the web in register with the following printing unit so that the web is still in register when the cylinders are reengaged for restarting of the press.

Since the driven rollers 46 and 48 of the register control devices R-2, R-3 and R4 are driven from the same rotary power source as the printing units, i.e., from the main press drive shaft 20, it is necessary, in order that the gravure cylinders may be rotated slowly as above described, that the drive rollers be disconnected from the shaft 20 during stoppage periods. As shown most fully in FIG. 3, this may be accomplished by means of a clutch 104 provided in the driving connection between each shaft 18 and the variable diameter pulley 58 driving the associated rollers 46 and 48.

Each clutch 104, as seen in FIG. 3, comprises a first serrated disk 106 keyed to a shaft 108 driven from shaft 18 and a second serrated disk 110 fixed to the pulley 58 and freely rotatable on and axially slidable along an extension 112 of the shaft 108. The

disks

106 and 110 are held in engaged position against the bias of a spring 114 by a solenoid 116 having its plunger connected to one end of a lever 118 which carries at its other end a pin 120 riding in a groove 122 in disk 110. The solenoids 116 associated with the respective clutches 104 of the several register control units are connected into an electrical circuit 124 which is broken by depression of the threading or service button 30a, whereby to deenergize the solenoids and allow the disks of each clutch to be moved to a disengaged position by the action of spring 114.

The maintenance of established register conditions from one operating period to another, notwithstanding stoppage of the machine and slow rotation of the printing cylinders during the period of stoppage, is further promoted by the provision of means which act to halt the rotation of each gravure cylinder at a predetermined angular position thereof whenever a signal to stop the press is given. Thus, after being rotated slowly during a period of press stoppage, the gravure cylinders are halted at the same angular positions they occupied when the press was initially stopped, so that when they are reengaged with the web they will continue to be in register with it.

Suitable means for this purpose include a cam 126 carried on a rotary element of the machine that is positioned according to the position of the printing cylinders, for example, as here illustrated, on the disk 106 of the clutch 104 provided for unit R-2. The cam 126 is adapted to engage a switch 128 during each revolution of the disk. The switch 128 is in an auxiliary electrical circuit 130 to the press driving motor M. The auxiliary circuit 130 also passes through a switch 132 controlled by the coil 134 of a relay 136, and through a switch 138 controlled by the upper coil 140 of a latch relay 142.

During operation of the press, the switch 132 of relay 136 is held in an open position by a circuit 144 passing through and energizing the coil 134 of this relay, so that depression of the switch 128 by the cam 126 as the press rotates has no electrical effect until a signal to stop the press is given by depression of button 30a.

Upon the depression of button 30d, the drive button 30b is released to break circuit 146 to the motor M, but simultaneously circuit 144 is broken so that the switch 132 is closed and the auxiliary circuit 130 is completed to the motor, which thereby continues to be energized. Closing of the switch 132 also completes a circuit 148 to the lower coil 150 of the latch relay 142, to energize that coil and pull the latch plate 152 controlled thereby clear of the switch 138. However, since closing of the switch 132 also completes a circuit 154 through the upper coil 140, the switch 138 remains closed until with continued rotation of the disk 106 the switch 128 is opened by the cam 126, thus breaking the circuit 130 to the motor and stopping the press. Means (not shown) are also provided to release the button 30d upon actuation of the switch 128 and thereby open the switch 132 so that the subsequent closing of the switch 128 as the cam 126 continues past it will not re-energize the motor.

After the press has stopped, the service button 30:: may be depressed to break the circuit 124 and disengage the

clutch disks

106 and 110. The gravure and pressure cylinders of each unit then may be separated (by means not shown), and the press restarted by depression of the button 30b to rotate the gravure cylinders slowly. After the servicing or threading operation has been completed, the press is again stopped by depression of the button 30a, the gravure cylinders being then stopped by the cam and relay mechanism above described in the angular position they assumed when the press was initially stopped, so that when reengaged with the web they will continue to be in register with it.

It will of course be apparent that prior to restarting the press to rotate the gravure cylinders during the servicing period it will be necessary to disengage all other web driving devices, such, for example, as the drives for the rollstand RS and any web driving elements of the turn bar system TB, from the main press drive shaft 20. This may be accomplished by electromagnetic clutches (not shown) which may be arranged to be deenergized and disengaged simultaneously with disengagement of the clutches 104 upon depression of the button 30a.

Separation of the cylinders at each printing unit causes the web to hang slack between successive register control devices or, in the case of the unit P-l, to hang slack between the register control device R-2 and the rollstand RS. It will be apparent that the movable rollers 44 of the tension control devices, if permitted to act under their normal bias, would run out this slack under the force of the fluid pressure in the cylinders 96 and tend to destroy the established register between the web and the processing units. To prevent this, means are provided to lock the roller 44 of each of the devices T-2, T-3 and T4 in the working position which it occupies prior to separation of the cylinders gripping the web at the processing stations. These means, as seen in FIG. 2, include for each unit such as T-2 an arm 156 formed at one of its ends with a notched arcuate surface 158 and mounted on the stub shaft 94 carrying the movable roller 44. A toothed finger 160 engageable with the notched surface 158 is formed on one end of a bellcrank 162 pivotally mounted on a stub shaft 164. The other end of the bellcrank is secured to one end of a spring 166 continually urging the bellcrank to move clockwise about the axis of shaft 164 to urge the finger 160 into engagement with a notch or serrations of the surface 158. This other end of the bellcrank is also connected to the plunger of a solenoid 168 which when energizezd holds the finger 160 out of engagement with the surface 158 against the bias of the spring 166.

The solenoids 168 respectively associated with the tension control devices T-2, T-3 and T-4 are connected into the electrical circuit 124 so that upon depression of the servicing button 30a, following stoppage of the press by depression of button 301), the rollers 44 are locked in their respective transient positions and are thus prevented from running out the slack introduced into the web upon the subsequent separation of the printing cylinders at the various units.

As previously indicated, the web in passing from one printing unit to the next is passed over a pluraliy of guiding rollers or cylinders. Some of these, such, e.g., as the cooling cylinders 36 of FIG. 2, have a relatively large mass and for that reason the usual practice has been to drive web guiding rollers from the main press drive so that they will rotate in unison with the printing units and cooperate with the latter to propel the web at uniform speed. However, because of expansion and concontraction of these rollers or cylinders due to variations of their temperature, their diameters tend to vary with the result that the speed at which they propel the web is also varied. Such speed differentials tend to produce excessive looseness or tightness of the web, thereby tending to produce register errors, side weaving or even breakage of the web.

According to a further feature of the present invention, the web guiding rollers or cylinders over which the web is trained to pass between successive processing units are arranged as free running or idler rollers, so that they may be driven peripherally by the friction of the web when the web is tensioned against them. Such an arrangement is entirely practical for normal starting and stopping of the press, at which time acceleration or deceleration is controlled and gradual. While it would ordinarily be impracticable, because of the need for emergency stops which require that the press stop quite abruptly, e.g., within a few revolutions of the processing cylinders, and would result in displacement or breaking of the web by the drag of the free running rollers, this problem is avoided according to the invention by the provision of means acting automatically to release the tension in the Web leads engaging these rollers whenever an emergency stop occurs, so that the rollers may coast to a stop without displacing or damaging the web.

These tension releasing means include, for each tension control device, a solenoid 170 having its plunger connected to the spool of a control valve 172 interposed in the conduit 98. The spool is continuously urged by a spring (not shown) toward a position in which communication between the cylinder 96 and the source of fluid pressure is blocked and the cylinder is vented through an exhaust conduit 174 to the atmosphere. The solenoid 170 when energized holds the valve spool against the resistance of its spring in a position in which the fluid presure cylinder is maintained in communication with the fluid source so as to tension the roller 44 against the web with a force dependent upon the setting of the pressure regulator 100.

The solenoids 170 associated with the tension control rollers 44 are connected into a circuit 176 which is broken by depression of the emergency stop button 30c, so that upon an abrupt stoppage of the press the fluid pressure.

1 1 on the rollers 44 is released to free the Web from tension against the guide rollers, including the cooling cylinders 36, and allow these normally Web-driven rollers to coast to a stop.

The circuit including the solenoids 170 also includes, in series with the solenoids, a plurality of web break detectors WB of known construction, which are held in a circuit closing position by the normal tension of the web but which move to a position to break the circuit 176 upon a substantial decrease in the sensed web tension occurring, for example, upon a break in the web. Accordingly, the pressure biasing the rollers 44 against the web is released upon an abrupt press stoppage occurring either as a result of depression of the emergency stop button 300 or as a result of a breaking or loss of tension of the web. It will be understood that the abrupt stop; page of the press ocurring upon breakage of circuit 176 is brought about by dynamic braking means (not shown) of known construction and operation.

If desired, the exhaust conduit 174 of any or all of the control valves 17;; may be provided with a pressure regulating device 178 that is adjustable to establish at any of various desired values the pressure of the fluid remaining in the cylinders after deenergization of the solenoids.

Whenever the press is stopped with substantial inequalities of web tension existing along the various leads of the web, there is a tendency for the web, in an attempt to equalize its tension, to rotate the web register units contacting it. A like tendency may result from accidental contact of the web with the rotating gravure cylinders or from changes in the press room temperature or humidity conditions. The register control units when not running may also tend to be rotated as a result of accidental jarring of parts of the press during work on them by operating personnel. Such rotation is made possible by the fact that these units are declutched from the main pres-s drive when the press is stopped. If allowed to take place, it would result in a shifting of sections of the web out of their registered relationship to the processing units. To prevent this, further means are provided according to the invention which act automatically upon stoppage of the press to clamp the web firmly at spaced locations therealong so that it will not exert a rotating force on the rollers of the register control units.

' Such clamping means are shown at the unit P-1 in FIG. 2 and are indicated generally as 180. Each of them includes a bellcrank 182 pivoted on a stub shaft 184. One end of the bellcrank 182 is formed with an arcuate clamping element 186 having a radius of curvature substantially equal to that of a web guiding roller 34 with which it is adapted to co-act. The other end of the bellcrank is secured to a spring 187 continually urging the bellcrank in a direction to move the clamping element 186 into engagement with the web passing over the roller 34. This end of the bellcrank is also connected to the piston of a fluid pressure cylinder 188 to which fluid under pressure is supplied through a conduit 190 at a pressure determined by the setting of a pressure regulator 192 interposed in conduit 190, and indicated by a pressure gauge 194 also interposed in conduit 190. A control valve 196 in the conduit 190 controls the delivery of fluid pressure to the cylinder. A solenoid 198 has its plunger connected to the spool of the valve 196 and normally holds the valve open against the resistance of an internal valve spring (not shown) to maintain fluid pressure in cylinder 158 and thereby hold clamping element 186 away from roller 34.

The solenoid 198 associated with the various clamping devices are connected into a circuit 200 which is broken by depression of either service button 30a or emergency stop button 30c, so that upon a depression of button 30a following a normal press stop, or upon an emergency stop of the press by depression of button 300,

the various web clamping devices 180 act to firmly grip the web and prevent longitudinal shifting of the same during the stoppage period.

Since all the rotating members of a printing press require at least a fraction of a revolution, and often appreciably more, in order to come to a stop, it is necessary to delay the action of the clamp devices 180 for a time, following a signal causing the press to stop, sufficient to insure that the web will be at rest when it is clamped. This delay is provided by incorporating a time delay relay 202 in the circuit to each clamping solenoid. Each relay 202 may be, e.g., one of the thermal type, which continues to conduct current for a fixed time after the electrical circuit including it is broken by a signal for a press stop, or by depression of service button 30a, after which time the electrical circuit to the solenoid is broken and the clamping device moved to its web clamping position.

It may be desired at various times to feed an unprinted or white web from the rollstand directly to the printing unit P-2, in which event the register control device R-2 cannot function for lack of register marks on the web. When this occurs it may happen that the carriage 52 of the device R-2 is so positioned that the rotational speed imparted to the rollers 46 and 48 by the belt contacting radius of the variable diameter pulley 58 is slightly too high or too low as compared to the speed of the printing units. Such a speed discrepancy will tend progressively to lengthen or shorten the web lead between the rollers 46 and 48 and the unit P-1 and correspondingly to displace the floating roller 44. That roller 44, however, will soon reach a limit of its range of movement, and if the speed discrepancy were allowed to continue the web tension would thereafter increase so as to break the web, or decrease so as to make the web lead uncontrollably slack.

In order to prevent any such difliculty, further means are provided according to the invention for automatically displacing the carriage 52 in the direction and to the extent required for eliminating the speed discrepancy, whenever the floating roller 44 reaches either limit of its normal range of movement. These means, as seen in FIG. 2, include an arm 204 formed as a lower extension of arm 156 of the tension control device T-2 and so arranged that as the roller 44 approaches either limit of its movement this arm 204 will actuate one switch of a pair of limit switches 206 and 205 disposed on either side of the arm. The switches 206 and 205 are electrically connected to the control panel by circuits 207 and 208, respectively. The circuitry is such that when either switch is actuated the pilot motor '70 is energized through the control panel 90 in a sense to move the carriage 52 in the direction to prevent the impending harmful increase or decrease in the web tension. A cut-off switch 209 is provided in the circuits 207 and 208 to incapacitate switches 206 and 205 when printed paper is being supplied to the unit P-2.

It is desirable under certain conditions that the energization of the pilot motor 70 and displacement of the carriage 52 in response to actuation of either of the switches 206 and 205 be made cyclical or intermittent. This is accomplished by the phasing device shown generally at 210 in FIG. 2. The device 210 includes a gear reduction unit 212 supported in a position adjacent to printing unit P-2 and driven from the latter by a belt 214 engaging a pulley 216 secured to the input shaft of the reduction unit. Secured to the output shaft of the unit 212 is a cam 218 which cyclically actuates a switch 220 in the electrical circuits 207 and 208 so that the motor 70 is energized only when one of the limit switches is actuated by the arm 204 and the switch 220 is actuated by the cam 218. A cut-off switch 222 is provided to electrically by-pass the switch 220 when continuous rather than intermittent energization of pilot motor 70 is desired.

FIGS. 4 and 5 show modified forms of register control devices which may be used ahead of the several printing or other web processing units in place of the device shown at R-2 in FIG. 2.

The register control device of FIG. 4 is similar to that of FIG. 2, excepting that its

web driving rollers

46a and 48a are mounted on a carriage 52a which is reciprocable by a pilot motor 70a along fixed guide rods 224. V-belt tensioning rollers 76:! are supported against the flights of the belt, so that a displacement of the carriage on the rods varies the length of the webpath and the stretch of the web lead from the register control device to the associated processing unit and simultaneously displaces the V-belt 56a relative to its tensioning rollers 76a, thereby varying the V-belt tension, the belt contacting radius of the pulley 58a and the rotational speed of the

rollers

46a and 48a.

In the register control device of FIG. 5, the web driving rollers 46b and 48b are mounted on fixed axes in the press frame, and the web W traveling from these rollers to the processing unit is passed about a displaceable roller 226 carried on one arm of a bellcrank 228, the other arm of which carries a belt tensioning roller 76b continuously bearing against the V-belt 5617. A pilot motor 70b is connected with the bellcrank so that upon rotation of the motor 70b for the correction of a register error, the web positioning roller 226 is displaced to vary the length of the web path and the stretch of the web lead to the associated processing unit, and the belt tensioning roller 76b is displaced correspondingly to produce proportional variations of the tension of the V-belt 56b, the belt contacting radius of the pulley 58b and the rotational speed of the web driving rollers 46b and 48b.

It will be understood that the references herein to maintaining a substantially constant web tension, such as in the lead of the web extending from one processing unit to the web-driving register control device associated with the next processing unit, do not imply that the tension will have the same magnitude in successive or differently directed sections of the same web lead. Although the magnitude of the tension is kept substantially constant in each section, it increases stepwise as the web passes successively in contact with rollers, bars or other elements guiding it along its path of travel, until the web reaches a Web propelling unit, such as the driven rollers of each register control device, that propels it with an energy input overcoming accumulated drag effects of the press elements previously contacting it.

When a machine according to the invention makes use of a conventional turn bar system for inverting the web as it is passed between two printing units, for example, as diagrammed .at TB in FIG. 1, a considerable drag is exerted on the web being drawn over the turn bars. The magnitude of the tension in the web section leaving the turn bars is, therefore, considerably greater than that prevailing in the web section entering them.

The tension value in each of those sections, as in each other section of the web lead extending from printing unit P-l, may be kept substantially constant by the action of a biased roller device, e.g., device T-2, for as long as the tension building effects of the two bars and of the other elements contacting the web lead are substantially constant and do not accumulate tension in the web to an excessive level before the web reaches the driving rollers of the register control device, e.g., device R-2.

In some circumstances, however, as where the web lead is likely to be subjected to irregular tension building effects before reaching the turn bar system, it is important to make sure that the tensions in the web sections entering and leaving the turn bars will be kept at selected, substantially constant values well suited to steady travel of the web over the bars and from them to the device registering the web to the next printing unit. Otherwise, difficulties tending to break the web, throw it sidewise along the bars, limit its speed and/or bring it out of register at the preceding printing unit are likely to be encountered at the turn bars.

Such difliculties can be materially reduced or avoided and the required steady travel of the web over the turn bars assured according to the embodiment of the invention illustrated in FIG. 6. This embodiment provides for the maintenance of a definite, pre-selected tension value in the web section entering or about to enter the turn bars and for the application of propelling energy to the web section leaving or closely beyond the bars, so as to overcome the accumulated drag on the latter and bring the tension level to a materially reduced magnitude as the inverted web beyond the bars is registered to the next printing unit.

The arrangement of FIG. 6 may be considered essentially the same as that hereinabove described for control of the web traveling between printing units P-1 and P-2 of FIGS. 1 and 2, exceptiong that the tension control and register control devices between the printing units, such as the devices T-2 and R-2 of FIG. 2, operate respectively on web portions just ahead of and closely beyond the turn bars, instead of being located away from the turn bars and closer to the second printing unit.

As seen in FIG. 6, a set of turn bars TBl and TB2 for inverting the web W, together with their bay window (i.e., a roller or rollers, not shown, engaging the web loop running between the two bars), is disposed between a register control device D and a floating roller device E that maintains substantially constant tension in the web lead extending from the first printing unit A to the register control device. The device D operates on the web lead extending to the second printing unit B, so as to held the web in register with that unit by variation of its stretch as above described.

The device D may be of any of the types shown in FIG. 6 or at R-2 in FIG. 2 or in FIG. 4 and FIG. 5. Its

web positioning rollers or roller are positioned by a pilotmotor PM in response to signals from a photoelectric register mark scanner C, essentially as described with reference to unit R-2 of FIG. 2. The tension control device E is similar to that shown at T-2 in FIG. 2.

The constantly biased floating roller at E establishes and holds a quite definite, selectable value of tension in the web section entering the turn bars. By keeping this value substantially constant, it also keeps the respective tension values in the web sections between and leaving the bars TBI and TB2 substantially constant, up to the point of driving engagement of the web W by the driven rollers of the register control device D. These rollers in turn continuously supply the energy required to propel the web away from the bars and to bring the tension level in the web lead leaving the rollers to a reduced average value enabling the device D to perform its register control functions without danger of overstressing that web lead. 1

In circumstances where the accumulated tension level in the web entering the turn bars may be too high, as Well as possible too irregular, for assurance of satisfactory operations at high web speeds, such, for example, as in the processing of delicate web material or in some cases of the use of an oven or other web heating means followed by cooling rollers for drying a printed paper web before it is inverted and passed to the next printing unit, it is advantageous not only to achieve the effects of the arrangement of FIG. 6 but also to have the definite tension level that is set and held in the web section entering the turn bars reduced substantially below the tension level normally built up in the web as it travels to the turn bar system.

To achieve this end, instead of providing as at E in FIG. 6 mere-1y a simple floating roller constantly biased against a loop of the web about to enter the turn bars, the tension control device there provided may be of a web propelling, floating roller type, such, for example, as illustrated at E1 in FIG. 7; and a simple floating roller hearing under constant bias against a loop of the web leaving the bars, as illustrated at E2 in FIG. 7, is disposed between the bars and the register control device D1 propelling the web away from the bars.

The tension control device E1 in FIG. 7 has web propelling rollers 700 and 701 mounted on a reciprocable carriage 702 and driven by a variable speed V-belt drive, in essentially the same manner as the register control device in FIG. 4. Instead of being positioned by a pilot motor, however, these rollers are held in a floating condition by a balance of several forces. The tension of the web section W1 being drawn to them and the reaction of their driving V-belt 704 to the pressure of that belt against the

rollers

705, 706 tensioning it continuously urge the carriage in one direction, while the tension of the web section W2 leaving the device to enter the turn bars and the pre-selected bias of the air cylinder 708 acting upon the carriage urge the carriage continuously in the opposite direction, i e., toward the turn bars.

Since the constantly biased floating roller 710 of device E2 keeps the tension level in the web section W5 leaving the turn bars at a constant value set by the air pressure in its air cylinder 712, substantially constant, though different, tension levels are also maintained in the respective web sections entering and passing between the turn bars. Therefore, the aggregate force urging the carriage toward the turn bars is substantially constant.

The aggregate force urging the carriage away from the turn bars is also constant when the tension in the web section W1 being drawn to the rollers 700, 701 is constant at a value in balance with the other forces acting on the carriage. The carriage then stands still and the web driving speed of its rollers is constant. But when a variation of tension begins to develop in the web lead approaching its rollers, the carriage moves incrementally to restore the balance of forces, and the tension of V- belt 704 is thus varied correspondingly so as to vary the speed of the rollers and thereby restore the tension in that web lead to a pre-set value determined by the pressure applied to the cylinder 708 biasing the carriage.

Accordingly, the tension in the web running to the turn bar system from the first printing unit is kept substantially constant by the action of tension control device E1, which device applies propelling energy to the web so that the web section W2 entering the turn bars can have a tension level reduced as desired for steady and reliable movement of the web over the turn bars; while the simple floating roller 710 of device E2 at the exit side of the bars sets and keeps the respective tension levels of the web sections entering, between and leaving the bars substantially constant at the desired values determined by the pressure applied to its air cylinder 712. Moreover, it does this notwithstanding the web registering actions of the device D1 which continuously propels and positions a portion of the web beyond device E2 so as to reduce the tension level produced in the web by the drag of the turn bars and to register the web lead drawn from device D1 to the next printing unit, in the manner hereinbefore described.

A further modification of the system according to FIG. 7 may be advantageous in cases where the cumulative drag of the two turn bars on the web would raise the tension level in the web section leaving them beyond a limiting value desired for the material being processed. For the avoidance of difliculties in such cases, a roller -or set of rollers guiding the web loop at the bay window of the turn bars may be made to serve as the variable speed floating roller means of a web propelling tension control device, as illustrated schematically at E3 in FIG. 8.

The device E3 is quite similar to the device E1 already described. Parts of it corresponding substantially to parts seen in FIG. 7 are indicated by corresponding primed reference numerals,

It will be understood that the rollers 700', 701' of wet propelling tension control device E3 at the bay window of the turn bar system will keep the web sect-ion WE running from the first turn bar TBl under a su-bstantialh constant tension determined by the setting of the fluic pressure in cylinder 708 biasing carriage 702' and tha they will propel the return web section W4 toward the second turn bar TB2 under a reduced level of tensior determined by the fluid pressure in the cylinder 712 biasing the floating roller 710 of device E2 (FIG. 7).

It will also be understood that where the turn bar sys tem is provided with a web propelling tension control device such as device E3 acting upon the web loop at the bay window, it may be feasible under some operating conditions to provide ahead of the first bar, instead of a similar device such as device E1, a simpler floating roller device as at E in FIG. 6; or even to dispense with all tension control means ahead of the first bar. For most conditions, however, the latter is not advantageous, and an arrangement such as that of FIG. 6 or FIG. 7 is to be preferred over one providing web propulsion and tension control at the bay window.

From the foregoing it will be seen that the present invention provides a system of apparatus for a multi-unit web processing machine which, whether the web is passed directly from unit to unit of the machine without inversion or is inverted between successive units so that it may be processed on first one and then the other side, acts quickly and positively to correct detected errors in the register of the web to each processing unit; performs its corrective function as to each unit without excessive hunting and without disturbing the register of the web to the other processing units of the machine; holds the web in registered relation to the various processing units during stoppage of the machine; and acts upon abrupt stoppage of the machine to free the various idler rollers peripherally driven by the web from constraint by the web and thereby prevent these rollers from damaging the web.

It will be seen, more particularly, that the present invention provides a system of apparatus for a multi-color rotary gravure press which acts, during operation of the press, to maintain correct register of the web to the various printing units and acts, upon stoppage of the press and freeing of the web at the printing units by separation of the coacting cylinder sets, to hold the web in place relative to the separated cylinders; and which acts to halt the cylinders following their slow rotation during the stoppage period at approximately the angular position they assumed when the press was initially stopped so that when reengaged with the web they will continue to be in register with it.

While illustrative embodiments of the invention have been shown and described, it will be understood that the new features of the invention can be utilized in many other ways and are not restricted to the illustrative embodiments except as may be required by a fair construction of the appended claims.

What is claimed is:

1. In a multi-unit web processing machine including first and second rotary processing units for engaging and propelling a web and between which the web travels under tension through an extended path, and means for driving said units in synchronism, each of said units normally holding the web in non-slipping relation thereto, said first unit having an element thereon that registers cyclically with successive points on the web which are to be maintained continually in register with an element on said second unit;

register control means, including driven roller means non-slippably engaging and propelling the web at a location between said units, for simultaneously and proportionally adjusting relative to the position and the speed of said second unit both the length of the path and the speed of that lead of the web which extends from said driven roller means to said second unit so as to keep the web substantially constantly in register with said second unit irrespective of the actual speed of said units, said register control means further including means for driving said roller means in synchronism with said units, and

means for varying the speed of said roller means relative to the speed of said second unit;

register correction means including means for detecting a deviation of said register points from registering relationship to said element on said second unit and means responsive to said detecting means for actuating said register control means to the extent and in the sense required to correct such deviation;

and floating roller means yieldably biased against and positioned by and counterbalancing the tension in the web lead to said driven roller means for maintaining said tension substantially constant.

2. A machine according to claim 1,

said floating roller means including a roller engaging and urged in one direction by the pull of a portion of the web lead to said driven roller means and means urging said roller in an opposite direction with a constant force so that the web tension in that lead is maintained at a value proportional to said force, said machine further comprising,

web guiding idler rollers engaged and driven by said web lead between said first unit and said driven roller means,

emergency control means for stopping the machine abruptly,

and means operative upon actuation of said energency control means to decrease said force and thereby the tension of said web lead to an extent suflicient to free said web guiding rollers from constraint by the web so that they may coast to a stop without damaging the web.

3. A machine according to claim 1, said driven roller means being displaceable in opposite directions longitudinally of said web path, and said actuating means including means for displacing said driven roller means in either of said directions and means for simultaneously adjusting said speed varying means by increments respectively proportional to the displacements of said driven roller means.

4. A machine according to claim 1, said register control means further including a displaceable idler roller at the downstream side of said driven roller means for positioning said web lead to said second unit, said idler roller being dispaceable in opposite directions longitudinally of said web path, and said actuating means including means for displacing said idler roller in either of said directions and for simultaneously adjusting said speed varying means by increments respectively proportional to the displacements of said idler roller.

5. In a multi-unit Web processing machine including a first set of coacting cylinders which impress a web at sucessive locations thereon and from which the web travels under tension through an extended path to a second set of coacting cylinders which impress the web at successive locations to be maintained continually in register with the first said locations;

register control means, including driven rol-ler means non-slipably engaging and propelling the web at a location between said sets of cylinders, tor simultaneously and proportionally adjusting relative to the position and the speed of said second set of cylinders both the length of the path and the speed of that lead of the web which extends from said driven roller means to said second set so as to keep the impressions of the web substantially constantly in register irrespective of the actual speed of said cylinder sets, said register control means further including means for driving said cylinder sets and said roller means in synchronism, and

means for varying the speed of said roller means relative to the speed of said second cylinder set,

register correction means including means for detecting a deviation of the first said locations from registering relationship to said second set and means responsive to said detecting means for actuating said register control means to the extent and in the sense to correct such deviation,

and roller means yieldably biased against and positioned by and counterbalancing the tension in the web lead to said driven roller means for maintaining said tension substantially constant.

6. A machine according to claim 5, including a clutch in the driving train to said driven roller means,

a member adapted to clamp the web so as to prevent movement thereof but normally held clear of the web,

and means operative upon disengagement of said clutch to move said member into web clamping position whereby to prevent rotation of the de-clutched roller means :by the web.

7. In a multi-unit web processing machine including a first set of coacting cylinders which imprint a web at successive locations thereon and from which the web travels through an extended path to a second set of coacting cylinders which imprint the web at successive locations to be maintained continually in register with the first said locations, each set of said cylinders non-slippably gripping and propelling the web;

coacting rollers engaging and for propelling the web in non-slipping relation thereto in a part of said path near to said second set,

a carriage mounting said rollers and movable bodily to displace said rollers in opposite directions longitudinally of the web path,

a carriage positioning means including a motor operative when actuated to move said carriage and thereby said rollers bodily relative to said first set of cylinders in either of said directions,

means for driving said cylinder sets and said rollers in synchronism, including a variable speed drive to said rollers the speed of which is varied upon and in proportion to movement of said carriage in either of said directions,

register corrections means including means for detecting a deviation of said first locations from registering relationship to said second set and means responsive to said detecting means :for actuating said motor so as to move said carriage and simultaneously vary the speed of said variable speed drive to the extent and in the sense required to correct such deviation,

and a floating roller yieldably biased against and positioned by a portion of the web lead to said rollers for maintaining the tension in that web lead substantially constant.

8. In a Web processing machine including a set of coacting cylinders which propel the Web and impress it at successive locations thereon and from which the web travels through an extended path to a further unit of the machine which propels the web and is driven in synchronism with said cylinders, said cylinders being separable during stoppage periods of the machine and freeing the web so as to create slack in it when separated;

a floating idler roller engaging the web in said path and yieldably biased against and positioned by the web for maintaining the tension of the web in said path substantially constant,

control means operative when actuated to stop the machine,

and means operative upon actuation of said control means to lock said floating roller in the position it then occupies to keep it from displacing the web freed by said cylinders during the stoppage period.

9. In a web processing machine including a set of coacting cylinders which propel the web and impress it at successive locations thereon and from which the web travels through an extended path to a further station of the machine with respect to which the impressed web is to be kept in register, said cylinders being separable during stoppage periods of the machine and freeing the web so as to create slack in it when separated;

a driven roll means non-slippably engaging and propelling the web in said path ahead of said station, means for driving said roller means in synchronism with said cylinders,

means operative upon said roller means for varying the speed of the Web portion engaged by said roller means relative to the speed of said cylinders,

register correction means including means for detecting a deviation of the web from registering relationship to said station and means responsive to said detecting means for actuating said speed varying means to the extent and in the sense required to correct such deviation,

a floating idler roller yieldably biased against and po sitioned by a portion of the web lead to said driven roller means for maintaining the tension in that web lead substantially constant.

control means operative when actuated to stop the machine,

and means operative upon actuation of said control means to latch said floating roller in the position it then occupies to keep it from displacing the Web freed by said cylinders during the stoppage period.

10. In a multi-unit web processing machine including first and second sets of coacting cylinders for impressing and propelling a web and between which the web travels through an extended path, and means for driving said sets in synchronism, the second set impressing the web at successive locations thereon which are to be maintained continually in register with impressions formed by the first set;

driven roller means non-slippably engaging and propelling the Web in a part of said path near to said second set,

means for driving said roller means in synchronism with said sets, including means operative upon said roller means for varying the speed of the web portion en gaged by said roller means relative to the speed of the web portion engaged by said second set to vary the stretch of the web lead extending from the roller means .to said second set,

register correction means including means for detecting a deviation of said impressions from registering relationship to said second set and means responsive to said detecting means for actuating said speed varying means in the sense required to correct such deviation,

a floating idler roller engaging and urged in one direction by the pull of a portion of the web lead to said driven roller means and means urging said roller in an opposite direction with a constant force so that the web tension in that lead is maintained substantially constant,

fixed web guiding idler rollers engaged and driven peripherally by said web lead between said first set and said driven roller means,

emergency control means operative when actuated to stop the machine abruptly,

service control means operative when actuated to stop the machine gradually,

means operative upon actuation of said emergency control means to decrease said force and thereby the tension of said web lead to an extent sufficient to free said fixed web guiding rollers from constraint by the web so that they may coast to a stop without damaging the web,

and means operative upon actuation of said service control means to latch said floating roller in the position it then occupies to keep it from displacing the web.

11. In a web processing apparatus including successive rotary web processing units to act in register up a continuously moving web and a floating roller normally biased against and tensioning a lead of the web between said units;

a latchable element connected with said roller to move therewith,

a latching member movable into engagement with said element to prevent displacement of said roller, said member normally being inactive,

means actuatable to press said member int-o engagement with said element so as to hold said roller against displacement,

a fluid pressure cylinder having a piston connected with said roller to bias the same against said web lead,

a conduit for supplying fluid under pressure to said cylinder,

a control valve in said conduit having a first position in which the fluid pressure in said cylinder is at a relatively high value and a second position in which said pressure is at least substantially reduced,

means continuously biasing said valve toward said second position,

means normally holding said valve in said first position against the force of said biasing means,

and means operable selectively either to actuate said means to press said member into latching engage ment with said element or to inactivate said holding means, whereby either to latch said roller in the working position it then occupies or to reduce the fluid pressure acting upon it so as to prevent it from displacing said web lead.

12. A web processing machine including;

a rotary power source,

coacting rotary processing cylinders drivingly engaging the web in non-slipping relation thereto, said cylinders being separable during stoppage periods of the machine and then freeing the web,

register control means, including driven rollers nonslippably engaging and propelling the web at a loca tion ahead of said cylinders, for simultaneously and proportionally adjusting relative to the position and the speed of said cylinders both the length of the path and the speed of that lead of the web which extends from said rollers to said cylinders so as to keep the web substantially constantly in register with said cylinders irrespective of their actual speed, said register control means further including means for driving said rollers and said cylinders in synchronism from said power source, and

means for varying the ratio of the speed of said rollers to the speed of said cylinders,

register correction means including means for detecting a deviation of said web from registering relationship to said cylinders and means responsive to said detecting means for actuating said register control means to the extent and in the sense required to correct such deviation,

means for continuing said cylinders in slow rotation by said power source during stoppage periods of the machine while said cylinders are separated from each other, 1

and a clutch in the driving train to said rollers whereby said rollers may be disconnected from said source and the web held in place relative to said cylinders during such stoppage.

13. In a web processing machine according to claim 12 wherein said power source comprises a motor,

a primary power circuit to said motor,

a first control switch having a first position in which said primary motor circuit is completed to supply power to the motor to energize the same and a second position in which said circuit is broken,

an auxiliary power circuit completed upon movement of said first switch to said second position to maintain a supply of energizing power to said motor,

a second control switch efifective when actuated and with said first switch in said second position to break said auxiliary circuit,

and means rotating with said cylinders for actuating said second switch in a predetermined angular position of said cylinders, whereby said cylinders are stopped in substantially the same angular position with each stoppage of the machine and continue to be in register with the web when reengaged therewith following the stoppage period.

14. In a rotary web processing machine including a first set of coacting cylinders which imprint one side of a web at successive locations thereon and from which the web travels under tension through an extended path to a second set of coacting cylinders which imprint the other side of the web at successive locations to be maintained continually in register with the first said locations, there being turn bars in said path for inverting the moving web;

register control means, including driven roller means non-slippably engaging and propelling the inverted web at a location between said turn bars and said second set of cylinders, for simultaneously and proportionally adjusting relative to the position and the speed of said second set of cylinders both the length of the path and the speed of that lead of the inverted web which extends from said roller means to said second set so as to keep the successive imprints on the web substantially constantly in register irrespective of the actual speed of said cylinder sets, said register control means further including means for driving said cylinder sets and said roller means in synchronism, and

means for varying the speed of said roller means relative to the speed of said second set;

register correction means including means for detecting a deviation of the first said locations from registering relationship to said second set and means responsive to said detecting means for actuating said register control means to he extent and in the sense to correct such deviation;

and floating roller means yieldably biased against and positioned by and counterbalancing the tension in the web about to enter said turn bars from maintaining substantially constant tension in the respective web section approaching and on the turn bars and extending from them to said driven roller means.

15. In a rotary web processing machine including a first set of coacting cylinders which imprint one side of a web at successive locations thereon and from which the web travels under tension through an extended path to a second set of coacting cylinders which imprint the other side of the web at successive locations to be maintained continually in register with the first said locations, there being turn bars in said path for inverting the moving web;

register control means, including driven roller means non-slippably engaging and propelling the inverted web at a location between said turn bars and said second set of cylinders, for simultaneously and proportionally adjusting relative to the position and the speed of said second set of cylinders both the length of the path and the speed of that lead of the inverted web which extends from said roller means to said second set so as to keep the successive imprints on the web substantially constant in register irrespective of the actual speed of said cylinder sets, said register control means further including means for driving said cylinder sets and said roller means in synchronism, and

register correction means including means for detecting a deviation of the first said locations from regis tering relationship to said second set and means responsive to said detecting means for actuating said register control means to the extent and in the sense to correct such deviation;

floating roller means yieldably biased against and positioned by and counterbalancing the tension in the inverted web between said turn bars and said driven roller means for maintaining substantially constant tension in web sections on the turn bars and beyond them to said driven roller means,

and variable speed, driven tension control means acting upon the web ahead of said turn bars to propel and to maintain substantially constant tension in the web lead from said first set of cylinders and to limit the tension level of the web section moving onto the turn bars, said tension control means being driven in synchronism with said cylinder sets and said driven roller means and being responsive to variations of the tension of the web traveling thereto to vary the speed of propulsion of the same in compensation for such tension variations.

16. A machine as defined in claim 15, further including variable speed, driven tension control means acting upon the web in the web loop between said turn bars to propel and to maintain substantially constant tension in the web at the first turn bar and to limit the tension level of the web section moving onto the second turn bar, said tension control means being driven in synchronism with said cylinder sets and said driven roller means and being responsive to variation of the tension of the web traveling thereto to vary the speed of propulsion of the same in compensation for such tension variations.

17. In a rotary web processing machine including a first set of coacting cylinders which imprint one side of a web at successive locations thereon and from which the web travels under tension through an extended path to a second set of coacting cylinders which imprint the other side of the web at successive locations to be maintained continually in register with the first said locations, there being turn bars in said path for inverting the moving web;

register control means, including driven roller means non-slippably engaging and propelling the inverted web at a location between said turn bars and said second set of cylinders, for simultaneously and pro portionally adjusting relative to the position and the speed of said second set of cylinders both the length of the path and the speed of that lead of the inverted web which extends from said roller means to said second set so as to keep the successive imprints on the web substantially constantly in register irrespective of the actual speed of said cylinder sets, said register control means further including means for driving said cylinder sets and said roller means in synchronism, and

means for varying the speed of said roller means relative to the speed of said second set,

floating roller means yieldably biased against and positioned by and counterbalancing the tension in the inverted web between said turn bars and said driven roller means for maintaining substantially constant tension in web sections at the turn bars and beyond them to said driven roller means,

and variable speed, driven tension control means acting upon the web in the web loop between said turn bars to propel and to maintain substantially constant tension in the web at the first turn bar and to limit tension level of the web section moving onto the second turn bar, said tension control means being driven in synchronism with said cylinder sets and said driven roller means and being, responsive to variations of the tension of the Web traveling thereto to vary the speed of propulsion of the same in compensation for such tension variations,

18. In a Web processing machine including a rotary unit for processing in register a Web traveling continuously thereto,

driven roller means non-slippably engaging and propelling the web lead to said unit,

an idler roller engaging said web lead at the downstream side of said driven roller means, said idler roller being displa-ceable to vary the position of said Web lead relative to said unit, means including a variable speed drive driven in synchronism with said unit for driving said roller means, said drive including an endless belt, means positioned and displaced with said idler roller for tensioning said belt, and means responsive to variations of the tension of said belt to vary correspondingly the ratio of the speed of said roller means to the speed of said unit, means for sensing deviations of the traveling web from registered relation to said unit and for generating signals proportional to the sensed register errors,

and means responsive to said signal to displace said idl'er roller and said belt tensioning means correspondingly so as to vary simultaneously the relative position of said Web lead and the speed thereof relative to the speed of said unit in the sense to correct the register errors.

References Cited by the Examiner UNITED STATES PATENTS 1,245,410 11/1917 Walkup 101-228 2,106,338 1/1938 Black 226-13 2,263,323 11/1941 Wickwire 101-182 2,281,900 5/1942 Wieking 101-180 X 2,469,283 5/ 1949 Steele 292-201 2,500,230 3/1950 Bailey et al. 226-30 X 2,549,605 4/1951 Huck 226-30 X 2,645,174 7/1953 Levin 101-132 2,699,937 1/1955 KOtte 226-60 2,700,447 1/1955 Bloggett 197-20 2,884,856 5/1959 Brodie 226-41 X 2,897,754 8/1959 Spiller et al 101-180 2,949,295 8/1960 Huck 226- 3,093,069 6/1963 Lu'ehrs 101-179 3,097,844 7/1963 Huck 226-30 X FOREIGN PATENTS 416,104 9/ 19-34 Great Britain.

ROBERT E. PULFREY, Primary Examiner.

J. R. FISHER, Assistant Examiner.

Claims

1. IN A MULTI-UNIT WEB PROCESSING MACHINE INCLUDING FIRST AND SECOND ROTARY PROCESSING UNITS FOR ENGAGING AND PROPELLING A WEB AND BETWEEN WHICH THE WEB TRAVELS UNDER TENSION THROUGH AN EXTENDED PATH, AND MEANS FOR DRIVING SAID UNITS IN SYNCHRONISM, EACH OF SAID UNITS NORMALLY HOLDING THE WEB IN NON-SLIPPING RELATION THERETO, SAID FIRST UNIT HAVING AN ELEMENT THEREON THAT REGISTERS CYCLICALLY WITH SUCCESSIVE POINTS ON THE WEB WHICH ARE TO BE MAINTAINED CONTINUALLY IN REGISTER WITH AN ELEMENT ON SAID SECOND UNIT; REGISTER CONTROL MEANS, INCLUDING DRIVEN ROLLER MEANS NON-SLIPPABLY ENGAGING AND PROPELLING THE WEB AT A LOCATION BETWEEN SAID UNITS, FOR SIMULTANEOUSLY AND PROPORTIONALLY ADJUSTING RELATIVE TO THE POSITION AND THE SPEED OF SAID SECOND UNIT BOTH THE LENGTH OF THE PATH AND THE SPEED OF THAT LEAD OF THE WEB WHICH EXTENDS FROM SAID DRIVEN ROLLER MEANS TO SAID SECOND UNITS SO AS TO KEEP THE WEB SUBSTANTIALLY CONSTANTLY IN REGISTER WITH SAID SECOND UNIT IRRESPECTIVE OF THE ACTUAL SPEED OF SAID UNITS, SAID REGISTER CONTROL MEANS FURTHER INCLUDING MEANS FOR DRIVING SAID ROLLER MEANS IN SYNCHRONISM WITH SAID UNITS, AND MEANS FOR VARYING THE SPEED OF SAID ROLLER MEANS RELATIVE TO THE SPEED OF SAID SECOND UNIT; REGISTER CORRECTION MEANS INCLUDING MEANS FOR DETECTING A DEVIATION OF SAID REGISTER POINTS FROM REGISTERING RELATIONSHIP TO SAID ELEMENT ON SAID SECOND UNIT AND MEANS RESPONSIVE TO SAID DETECTING MEANS FOR ACTUATING SAID REGISTER CONTROL MEANS TO THE EXTENT AND IN THE SENSE REQUIRED TO CORRECT SUCH DEVIATION; AND FLOATING ROLLER MEANS YIELDABLY BIASED AGAINST AND POSITIONED BY AND COUNTERBALANCING THE TENSION IN THE WEB LEAD TO SAID DRIVEN ROLLER MEANS FOR MAINTAINING SAID TENSION SUBSTANTIALLY CONSTANT.