US2229683A

US2229683A - Apparatus for maintaining register in multiunit presses

Info

Publication number: US2229683A
Application number: US248217A
Authority: US
Inventors: Stoessel Max
Original assignee: Individual
Current assignee: Individual
Priority date: 1938-12-29
Filing date: 1938-12-29
Publication date: 1941-01-28
Anticipated expiration: 1958-01-28

Description

Jan. 28, 1941. 2,229,683

APPARATUS FOR MAINTAINING REGISTER IN MULTIUNIT PRESSES M. s'roEssEL.

2 Sheets-Sheet l INVENTOR 7 Sta-06 v'X-uf ATTORNEY &

Filed Dec. 29, 1938 Jan. 28, 1941. M, STOESSEL 2,229,683

APPARATUS FOR MAINTAINING REGISTER IN MUL'I'IUNIT PRESSES Filed Dec. 29, 1938 2 Sheets-Sheet 2 v INVEN St w 4 e Patented Jan. 28, 1941 STATES APPARATUS FOR MAINTAINING REGISTER IN MULTIUNIT PRESSES Max Stoessei, Ridgewood, N. 3., assignor to Arthur Dultgen, Queens Village, N. Y.

Application December 29, 1938, Serial No. 248,217

11 Claims.

This invention relates to apparatus for maintaining register in multiunit presses.

In the operation of multi-color web printing presses, serious difiiculty has been experienced in maintaining the register of the prints applied by the different printing cylinders, and manual adjustment of the position of the web in the different print units has been necessary during any long continued operation of such a press in order to obtain passably good register. The maintaining of register is more diflicult in intaglio or gravure printing presses than in others and is so great as seriously to retard the use of such presses for multi-color work.

The apparatus which I have invented for maintaining register in multiunit presses consists of a mechanical governing mechanism actuated by variations in the tensions of the reaches of the web between the printing -units to make gradual slight changes in the relative speeds of web-moving members associated with the units so as to restore the tension on each reach of the .web to its original value. In applying my invention to intaglio multi-color presses, where the need for it is greatest, I utilize the impression roller of each unit/as the Web-moving member and apply the governingineans to make gradual slight changes in thespeeds of the impression rollers. 30 An important feature of my governing apparatus, which leads to simplicity in construction and accuracy in operation, lies in the fact that it is purely mechanical and without introducing an outside source of power utilizes the actual tension of the web to apply a gradually increasing force to mechanism controlling the speed of the web-moving means.

In the accompanying drawings, I have shown the application of my invention to a standard intaglio multiunit press. In the drawings,

Fig. 1 is a side elevation of an intaglio press provided with apparatus embodying my invention;

Fig. 2 is a fragmentary top view of the movable rolls of one of the units;

Fig. 3 is an enlarged end view of the lower part of one of the units;

Fig. 4 is a vertical section on the line 4-4 of Fig. 3; 50 Fig. 5 (on Sheet 1) is a horizontal section on v the line 55 of Fig. 3; and

Fig. 6 (on Sheet 1) is a fragmentary verticizl section on the line 66 of Fi 3. The printing press shown in Fig. 1 has a main frame I on which are mounted printing cylinders 2, impression rollers 3, an unwinding or supply roll 4, a rewinding roll 5, feed rolls 6 for, the unwinding and rewinding rolls, and guide rolls 1 for guiding a web A from the unwinding roll 4 successively between the printing cylinder and impression roller of each of the printing units of the press and then to the rewinding roll 5. The printing cylinders of all the units are driven at the same rotational speed by the usual mechanical gearing from a common drive shaft D.

The reaches of the web between the printing units and also the reach of the web between the unwinding roll 4 in the first printing unit and that between the last printing unit and rewinding roll 5 pass over control rolls 9, In, H, I 2. The rolls 9 and I2 of each unit are fixed on the frame of the machine while each pair of rolls [0 and II are mounted on a tilting frame l3 whose axis is a cross-shaft I4 journalled in. the frame of the press and projecting through one side of the frame to serve as the mounting for a lever l5. It is evident that any difference in tension between the reach of the web entering a unit and the reach of the web leaving this unit will exert a turning force on the frame l3 and the lever l5. This force is utilized to effect a gradual slight change in the speed of the impression roller of the unit until equality of tension is restored. The impression roller 3 of each unit is driven from the mechanically driven shaft of the printing cylinder 2 of the unit through a differential mechanism 20 of known construction, provided with brake disks 2! and 22. When both brake disks are free to rotate, the impression roller 3 is driven at such a rate that its peripheral speed is approximately the same as that of the printing roller 2. When the brake disk 2! is held against rotation, the differential mechanism 20 operates to drive the impression roller 3 at a peripheral rate slightly greater than that of the printing 0 cylinder 2, while, when the brake disk 22 is held against rotation, the mechanism 20 operates to drive the impression roller at a peripheral speed slightly less than that of the printing cylinder 2. Tilting forces applied to the lever I5 by differences in tension of the different reaches of the web are utilized to cause the gradual application of braking pressure to one or the other of the brake disks 2| and 22. The mechanism for accomplishing this will next be described.

Brake shoes 23 and positioned to engage the :brake disks 2| and 22 respectively are carried by pairs of rods 25 slidably mounted in a bar 26 secured to the front of the casing 21 of the differential mechanism 20 and spaced outwardly 5o shoes are efiected by

toggles

30, 3| operated by a shaft 32 journalled on the bar 26 and connected with the lever l5 by a'crank 33 and a connecting rod 34, so that tilting movements of the lever l-5 cause turning movements of the shaft 32. A weight 34' is provided to counterbalance the weight of the connecting rod 34.

Each of the toggles consists of a threaded stud 35 screwed in a transverse bore in the shaft 32 and a rod 36 extending from the inner end of the stud to the brake shoe. The inner ends of the studs 35 and the outer surfaces of the brake shoes 23, 24 contain spherically curved recesses which hold the spherically curved, convex ends of the rods 36. When the lever I5 is horizontal, the

toggles

30, 3| are bent in opposite directions, as shown in Fig. 4. A tipping of the lever IS in either direction, causing a turning of the shaft 32, straightens one or the other of the toggles and thus forces one or the other of the brake shoes against the corresponding brake disk. In straightening, each toggle gradually applies a braking force which becomes a maximum when the toggle is straight and is then sufficient to lock the disk against any movement. Turning of the shaft 32 in either direction is limited to that necessary to straighten one or the other of the toggles by the engagement of a stud 31 fixed on the shaft with the bar 23 (Figs. 3 and 6). The braking force applied by each toggle may be regulated by screwing its stud in or out in the shaft 32 and by adjusting the nuts 29 to vary the tension of the springs 28.

It will be seen that the mechanism connecting the lever l5 of each unit with the brake shoes 23, 24 of that unit, which has been described, provides a simple and direct mechanical means for utilizing the difference in the tensions of the reach of the web entering the unit over the roll l2 and that leaving the unit over the roll II to apply gradually a braking pressure to one or the other of the brake disks of the differential mechanism through which the impression roller of the unit is driven.

The operation of the apparatus described is as follows:

The web is initially led through the machine as shown in Fig. 1 in such manner that the tension on the different reaches of the web is uniform, so that each of the swinging frames l3 and levers i5 is in horizontal position. This places the toggles of each unit in the bent position shown in Fig. 4, allowing the springs 28 to draw the brake shoes free from the brake disks. Each impression roller 3 is then driven at a rotational speed directly proportional to that of the printing cylinder of the unit, so that the rates of speed of the web through the different units are proportional to the peripheral speeds of the impression rollers which exercise a greater friction on the web than the printing cylinders. Since it is impossible to make the impression rollers of absolutely uniform diameter, the peripheral speeds of the impression rollers will vary slightly when all the impression rollers are thus driven at the same rotational speed. For the sake of illustration, it will be assumed that the diameter of the impression roller of the middle unit is slightly larger than the other impression rollers, so that, when the levers are all in neutral position, the web travels through this unit a little more rapidly than through the other units. This will result in increasing the tension on the reach of the web between the first and second units and decreasing the tension on the reach of the web between the second and third units. As soon as this difierence in tension starts to develop, the web will apply a turning force to the frame l3 and lever IS in a. clockwise direction (Fig. 1). This turning force is applied through a connecting rod 34 andthe crank 33 to cause a turning force on the shaft 32 in an anti-clockwise direction (Fig. 4). This force gradually overcomes the pressure of the springs 28, straightening the toggle 3i and pressing the brake shoe 24 against the brake disk 22. The retarding of this brake disk operates the differential mechanism 20 to decrease the speed of the impression roller. The decrease in speed of the impression roller results in the decrease of the rate of travel of the web through the middle unit which continues until the tensions of the web on the opposite sides of the middle unit again become equal, relieving the frame I3 and lever 65 of any turning force from the web and allowing the springs 28 to draw the toggle it into bent position to release the brake shoe from the brake disk so that the impression roller 3 is again driven at its original speed.

If the diameter of the impression roller of the second unit happens to be less than that of the impression rollers of the other units, a similar but oppositeadjustment will be caused by the turning force on the frame 83 and lever IS in the direction opposite from that inthe illustration just described, so that it straightens the toggle 30 and applies the brake shoe 23 to the brake disk 2! to increase the speed of rotation of the imprcssion roller.

The maximum changes in the speed of rotation of the impression roller which can occur in the automatic adjustments described is limited by the design of the differential mechanism to a comparatively small increment or decrement of the normal speed of the roller. Such maximum J changes of speed occur only when one or the other of the brake shoes is pressed inward with a force sufiicient to stop the rotation of one of the brake disks. During the gradual application of the braking force, the brake disk is at first merely retarded to a greater and greater extent. Such retarding causes changes in the speed of rotation of the impression roller less than the maximum change which is caused when the brake disk is stopped. Since the efiect of the change in the speed of rotation of the impression roller is to eliminate the difierence in tension which is causing the braking effect on the disk, the restoration of normal conditions may be achieved before sufllcient braking pressure is ap plied to stop the rotation of the brake disk. The automatic adjustment is thus very delicate and certain.

Where, as is usually the case, there are slight difierences in diameter between all the impression rollers, automatic adjustments suchas have been described will occur in all the units whenever any variations in the tensions of the reaches of the web develops and in this way register will be repeatedly restored and the average rates of travel of the web through each of the units will be maintained exactly the same no matter how long the press may operate.

The same result will be achieved in case the impression rollers are frictionally driven from the printing cylinders when there is no turning force on the lever I5, as in this case differences in the speed of the web through the different units caused by differences in the diameters of the printing cylinders will be compensated for by the automatic adjustment. Frictional, instead of positive, driving of the impression rollers during the neutral periods may be obtained by allowing-a little lost motion between the differential mechanism 20 and the shaft of the impression roller or in other ways. It will be understood, therefore, that the invention is not limited to any particular arrangement of the roller driving mechanism, nor is it limited to the use of impression rollers as the means for controlling the speed of the web.

What I claim is:

1. A device formaintaining register in a multiunit rotary web printing press, comprising a webmoving means associated with the printing unit and in continuous driving contact with the web, a differential driving mechanism for the webmoving means having two brake disks and arranged to cause an increase in the speed of the web-molving means when one of said disks is held against rotation and a decrease in the speed of the web-moving means when the other of said disks is held against rotation, brake shoes opposed to said brake disks, means for guiding the web to and from the printing unit, a movable support for said guiding means which is tilted in one direction when the tensionof the web entering the printing unit is greater 'than the tension of the web leaving the printing unit and tilted in the other direction when the tension of the web entering the printing unit is less than the tension of the web leaving the printing unit, and a mechanical connection between said support and the brake shoes to urge the brake shoe against one disk when the support is tilted in one direction and against the other disk when the support is tilted in the opposite directioi' 2. In a device for maintaining register in multiunit presses, the combination with a lever which is tilted by changes in the tension of different parts of the web and a diiferential driving mechanism for a web-moving means provided with two brake disks, of a shaft adjacent to the brake disks, a connection between said shaft and said lever which turns the shaft in one direction when the lever is tilted in one direction and in the opposite direction when the lever is tilted in the other direction, a pair of oppositely bent toggles connected to said shaft, a brake shoe associated with each toggle and opposed to one of said brake disks so that a straightening of the toggle with which it is associated forces it against said brake disk.

3. In a device for maintaining register, the combination of two brake disks, two brake shoes, resilient means for urging said brake shoes away from said brake disks, toggles for urging said brake shoes towards said brake disks and normally bent in opposite directions, a shaft supporting said toggles and adapted to straighten one of them to force one brake shoe against one brake disk when turned in one direction and to straighten the other of them and force the other brake shoe against the other brake disk when turned in the opposite direction.

' 4. In a multiunit rotary web printing press, a device for keeping the printing of two units in register comprising web-moving means associated with each 'unit and in continuous driving contact with the web, and means operated by changes in the tension of the reach of the web between the two units to gradually increase the peripheral speed of the web-moving means of one unit and gradually decrease the peripheral speed of the web-moving means of the other unit until the tension of said reach is restored to a predetermined value.

5. In a multiunit rotary web printing press, a device for keeping the printing of two units in register comprising a web-moving means associated with each unit and in continuous driving contact with the web, and means automatically actuated by a slight change in the tension of the reach of the web between the two units to cause a slight increase in the peripheral speed of the webmoving means of the one unit and a slight decrease in the peripheral speed of the web-moving means of the other unit and actuated by greater changes in the tension of said reach to cause greater changes in the speed of the web-moving means of the units.

, 6. In a multiunit rotary web printing press, a device for keeping the printing of two units in register comprising a web-moving means associated with each unit and in continuous driving contact with the web, a differential driving mechanism for the web-moving means of one unit havin a brake disk and arranged to increase the speed of the web-moving means by a predetermined amount when this disk is held against rotation, a difierential driving mechanism for the webmoving means of the other unit having a brake disk and arranged to decrease the speed of the web-moving means by a predetermined amount when this disk is held against rotation, and means automatically actuated by a change in the tension of the reach of the web between the units to retard said disks when the change in tension is slight and to hold said disks againstmotation when the change in tension is greater.

7. A device for maintaining register in a multiunit rotary web printing press comprising a webmoving means associated with each unit of the i press and in continuous driving contact with the web, means for driving the webmoving means at a normal speed, separate braking means for causing an increase and adecrease in the speed of the web-moving means, and mechanical means for applying to one of said braking means a force. created by the difierence in the tensions of the reaches at opposite sides of the unit, said force being applied to one braking means when the tension of .the entering reach is greater and to the. other braking means when the tension of the leaving reach is greater.

8. In a multiunit rotary web printing press, a device for maintaining register comprising a webmoving means associated with each unit of the press and in continuous driving contact with the web, braking means for increasing the speed of the web-moving means, separate braking means for decreasing the speed of the web-moving means, and means for applying to one of said braking means a force which is a direct function of the difference in the tensions of the reaches of the web entering and leaving the unit, said force being applied to one braking means when the tension of the entering reach'is the greater and to the other braking means when the tension of the leaving reach is the greater.

9. In a multiunit rotary web printing prem, a device for maintaining register comprising a webmoving means associated with each unit and in continuous driving contact with the web, braking means for increasing the speed of the web-moving means, braking means for decreasing the speed of the web-moving means, and means operated by a difierence in tension of the reach of theweb entering the unit and the reach of the web leaving the unit to gradually apply a braking force to the first of said braking means when the tension of the leaving reach is the greater and to the second of said braking means when the tension of the entering reach is the greater.

10. A device for maintaining register in a multiunit rotary web printing press comprising a webmoving means associated with each printing unit and in continuous driving contact with the web, a variable speed driving mechanism for the webmoving means having a brake mechanism to increase its speed above normal and a separate braking mechanism to decrease its speed below normal, guides for directing the web to and from the printing unit, a support for said guides movable under the eifect of difierences in tension of the entering and leaving reaches of the web, said support being movable in one directionwhen the tension of the entering reach is the greater and movable in the opposite direction when the tension oi. the leaving reach is the greater, and a mechanical connection between said support and each of said braking means.

11. A device for maintaining register in a multi- 5 disks and arranged to cause an increase in the 10 speed of the web-moving means when one of said disks is held against rotation and a decrease in the speed of the web-moving means when the other of said disks is held against rotation, means operated by a difierence in the tension of the 15 reach of the web entering the unit and the reach of the web leaving the unit to gradually apply a braking force to one of said braking disks when the tension of the entering reach is the greater and to the other of said braking disks when the 20 tension of the leaving reach is the greater.

MAX S'IOESSEL.