US2231187A - Printing press - Google Patents

Description

Feb, 11, 1941, Y

`J. F. HAWLEY PRINTING rmass Filed sept.. so, 1940 2 Sheets-S heet l J. F. HAWLEY PRINTING PRESS Feb. T1, 1941.

Filed Sept. 30, 1940 2 Sheets-Sheet 2 dil Patented Feb. 1l, 1941 UNITED STATES PATENT orrics 9 Claims.

This invention relates to a printing press, and more particularly to a printing press attachment for effecting registration of multi-color printing plates.

In multi-color printing presses it has heretofore been proposed to use flexible printing plates, formed of rubber, rubber composition or the like, which are provided on their backs with a pressure sensitive adhesive coating. The difllculty with such adhesive backed printing plates is in properly positioning the plates upon the printing rollers. In some instances marks have been made on the surface of a printing roll to which a plate is to be amxed, so as to indicate the proper position for the plate, but that method has not proved entirely satisfactory where exact registration is required. It has usually been necessary to position an adhesive backed printing plate by a trial and error method, which entails considerable time owing to the fact that the printing plate must be entirely separated from the surface of the printing roll between successive steps of amxing the plate to the surface of the roll.

In accordance with the invention described and claimed in a copending application entitled Printing plate and method of making same, Serial No. 358,977, filed September 30, 1940, I provide each printing plate with a pair of properly located holes, so that where two or more printing plates are used in conjunction for effecting the imprint of different colors, the holes in each of the plates are in the same position with reference to the design, or printing indicia carried by the plate. In my present invention I utilize the perforations of the printing plate for properly positioning the plate both angularly and circumferentially of the printing roll. This is accomplished by means of swingable arms adjustably mounted for movement along rotatable shafts mounted in stationary bearings so as to be parallel to the axes of the printing rolls. A pair of such arms is mounted on each of the shafts and carry pins for insertion in the apertures of the printing plate to temporarily support such printing plate while the arms are swung into position against the printing roll. Each shaft may be graduated or otherwise indexed in order that all of the arms on the separate shafts may be set at the same spaced position lengthwise of the printing rolls.

In addition, I provide an angular indexing arrangement, which may comprise a wheel carried by at least one of the printing roll shafts and a stationary pointer cooperating withgraduations or indexing marks on the wheel, or the marks can (Cl. lill-171) be placed on the periphery of the printing roll itself. Since each of the printing rolls is connected to another through a train of gears, one setting of one printing roll is sufilcient to bring all of the printing rolls into the same angular relationship.

It is therefore an important object of this invention to provide a multi-color printing press having means for applying to the printing rolls thereof adhesive backed flexible printing plates each in proper angular and lengthwise registration with each other.

It is a further important object of this invention to provide means in association with a multicolor printing press employing flexible printing plates having positioning holes therein, means for applying such printing plates in registration with each other, including swingable arms having positioning pins for insertion into the holes of the printing plates to temporarily hold said plates as the same are brought into contact with and adhesively secured to the surfaces of the printing rolls.

It is a further important object of this invention to provide a method for angularly indexing the rolls of a multi-color printing press and the like and other means for positioning printing plates on said printing rolls in exact registration with each other.

Other and further important objects of this invention will be apparent from the disclosures inthe specification and the accompanying drawings.

On the drawings:

Figure l is a side elevational view of a multicolor printing'press illustrating attachments embOdying the principles of my invention.

Figure 2 is a fragmentary top plan view of a printing roll and attachment.

Figure 3 is an enlarged end view, partly in section, illustrating the method of applying a exible printing plate to a printing roll.

Figure 4 is an enlarged fragmentary detail view of a plate positioning arm and pin.

Figure 5 is a plan view of a flexible printing plate.

In Figure 1 is illustrated a multi-color printing press of more or less conventional construction, including a stationary frame IB on which are mounted printing rolls II, I2 and I3 and cooperating backing rolls I4, I5 and I6. A movable frame I1 is suitably mounted upon a pair of tracks I8 for movement thereover by means of a rack I9 and pinion 20. Said frame I1 carries the usual form rolls 2l and ink distributing rolls arm 35 into any moved up into association with the stationary frame III, to apply the ink, color or the like to the printing rolls II, I2 and I3.

A roll of paper upon the stationary frame I 0. A web 24 of paper from the roll 23 is fed between the cooperating backing and printing rolls and then over suitable guide rollers 25 to a reel 26, where the printed paper is rewound.

In accordance with the principles of my present invention, the printing is accomplished by means of flexible printing plates 21 (Fig. 5), which may be formed of a laminated rubber composition base 28 having raised printing indicia 29 thereon. In multi-color jobs, each of the printing plates 21 carries the printing indicia for imprinting the color that is to be applied by means of that printing plate. The composite of the imprints from the successive printing plates makes up the finished multi-color imprint. It is therefore essential that each of the printing plates be properly positioned on the respective printing rolls so that the proper registration of the successive imprints may be effected. As an aid to effecting proper registration in accordance with my present invention, I provide a pair of holes or apertures 30 and 3I adjacent the opposite side margins of each plate 21. These holes 3U and 3| are in the same relative position with respect to the printing indicia on each of the printing plates used in the printing press, thereby insuring proper registration of the successively applied imprints.

The attachment for positioning the printing plates 21 on the surfaces of the printing rolls II, I2 and I3 will now be described. A rotatable shaft 32 is mounted below each of the printing rolls between the side members of the stationary frame I0. Since all of the shafts and their associated parts are identical, only one need be described.

As best shown in Figures 2 and 3, each of the shafts 32 is provided with a flat face 33 -on which are marked graduations 34. The graduations 34 need be in no particular units of measurement. but should be sufficiently closely spaced to enable exact registration of the printing plates lengthwise of the printing rolls.

On each of the shafts 32 arms 35 and 36. Each of said arms includes a hub or collar portion 31 which encloses the shaft 32 and which is keyed thereto by means of longitudinally extending strips 38 secured to said shaft 32. A set screw having a knurled head 39 and a threaded shank 40 extends through the hub 31 into engagement with the shaft 32 to secure the adjusted position lengthwise of the shaft 32. A pointer or indicator 4I is associated with each hub 31 to provide an edge closely overlying the graduations 34 to assist in setting the arms in the desired positions lengthwise of the shaft 32.`

Each of the arms 35 is provided with an inner curvature 43 that conforms more or less with the curvature of the printing roll, in order that the free end of the arm may be brought into closely spaced relationship with the surface of the printing roll. In'order to make the arms lighter in weight, while still preserving their rigidity, spaced openings 44 may be provided along the length of the arms.

At the free end of each arm, the arm is provided with a transverse bore 45, into which is inserted a rod 46. The rod 46 is held in place by is mounted a pair of 23 is adapted to be mounted Figure 3.

2,231,187 22, which are adapted, when the frame I1 is means of screws 4.1. 'Ihe projectingend of each rod 46 is cut away as at 48 and a pin 49 amxed theretowith its axis, when the associated arm 35 is brought into position against the surface of a. printing roll, extending roll. Each pin 48 is provided with a reduced end 50 of the same diameter as one of the holes 30 or 3|.

Thus, in positioning a printing plate 21 against the surface of a printing roll, such as the roll II, the printing plate is first suspended from a pair of arms 35 and 36 while the arms are in a lowered position,

The spacing of the arms 35 and v36 is such that each of the reduced ends 50 can be inserted into one of the holes 30 and 3| of the printing plate without stretching or buckling the plate longitudinally. The arms 35 and 36 are then swung into the full line position shown in Figure 3 by rotation of the shaft 32, until the ends of the reduced portions 50 of the pins 49 are in contact with the surface of the roll II. The printing plate 21 is then pressed against the roll surface throughout its entire area and caused to adhere thereto by reason of the pressure sensitive adhesive with which the base of the plate is coated. After the` printing plate has been positioned in place, the arms 35 and 36 are lowered, the thumb screws 39 released, and the arms moved to the outer ends of the shaft 32 into their inoperative position indicated in dotted lines on Figure 2.

In order that the several printing rolls il, I2 and I3 may all be adjusted to the proper angular position, I provide an indexing mechanism comprising a wheel 5I secured to an extended end of one of the printing roll shafts, such as the upper shaft 52, and a stationary ann 53 secured to the frame I0 as at 54 and having a straight edge 55 for registration with one of the indexing marks 56 on said wheel 5I. Since the several printing rolls Il, I2 and I3 are positively driven by a common train of gears, including the gears 66 on the ends of said printing roll shafts and idler gears 51, a. setting of the upper printing roll II automatically brings the other printing rolls I2 and I3 into the same angular relationship. Accordingly, where there are a plurality of printing plates about the peripheries of each of the printing rolls, the upper printing roll II is turned to the proper setting on the indexing wheel 5I, the first set of printing plates positioned in place on the respective printing rolls II, I2 and I3, and then the upper printing roll II is turned to the next indexing position on the wheel 5I at which a second set of plates is to be positioned, and so on until all of the sets of plates have been aiilxed to the printing rolls. It is preferable to have the diameter of the wheel 5I about twice that of the printing rolls, so that an error, say of 5*," in the setting of the wheel 5l, results in an error of only one- Preferably, however, a manually operable wheel, acting through a train of reduction gearing (not shown) is employed, since on relatively heavy presses it would obviously be rather of a task to turn all of the printing rolls through the train of gearing that serves to drive them. This train of gearing along -a radius of said v as illustrated in dotted lines in is not shown in toto, but is indicated by gears 03 on the driven ends of the printing rolls, II, I! and I3, and idler gears 51, which mesh therewith and also with the gears (not shown) on the driven ends of the back rolls Il, I5 and I6. Because of this common train of gears between the printing rolls II, I2 and I3, the setting of the upper printing roll II by means of the indexing mechanism, consisting of the wheel 5I and pointer 55, serves to index the other printing rolls I2 and I3 to the same angular relationship. It will be appreciated, of course, that in adjusting the printing rolls tc the same angular relationship, the indexing wheel 5I is always turned in the same direction each time, to bring the proper graduation line 55 under the straight edge 55 of the pointer arm 53. Otherwise, there might be sufficient backlash in the train of gears to give rise to an error in the indexing.

If there are three printing plates to be positioned about each of the printing rolls II, I2 and I3, their center lines will obviously be spaced apart about the circumference of the rolls. In this case, therefore, three graduation lines 56, spaced 120 apart on the wheel 5|, will be employed in the indexing operation. Similarly, if there were six printing plates to be positioned on each printing roll, six equally spaced graduation lines 56 on the indexing wheel 5I would be brought successively under the straight edge 55 of the pointer arm 53.

It is thus possible, by the use of my indexing mechanism, to insure proper registration of the printing plates on a multi-color printing press, and to do this with a minimum of labor and effort. The attachment described is particularly applicable to multi-colored printing presses Where adhesive backed flexible printing plates are employed, since it eliminates much of the diihculty heretofore experienced in positioning such printing plates correctly in the first instance. The method of positioning adhesive backed flexible printing plates, using my equipment, does away entirely with the hit or miss manner of positioning that type of printing plate, as previously practiced.

It will, of course, be understood that various details of construction may be varied through a wide range without departing from the principles of this invention and it is, therefore, not the purpose to limit the patent granted hereon otherwise than necessitated by the scope of the appended claims.

I claim as my invention:

1. In a printing press including a printing press roll on which printing plates are adapted to be positioned, means for insuring proper registration of such printing plates comprising a member parallel to the axis of the printing roll having graduation indicia associated therewith, arms swingable with and movable along said member and plate engaging means carried by said arms and movable with said arms to apply the plate to the printing roll at a position determinable by reference to said indicia.

2. In a printing press including a printing press roll on which printing plates are adapted to be positioned, means for insuring proper registration of such printing plates comprising a rotatable shaft parallel to the axis of the printing roll having graduation indicia associated therewith, arms swingable with and movable along said shaft means for securing said arms at any predetermined point along said shaft and plate engaging means carried by said arms and movable with said arms to apply the plate to the printing roll at a position determinable by reference to said indicia.

3. In a printing press including a printing roll and flexible printing plates adapted to be adhesively secured thereto, means for insuring proper registration of said printing plates comprising a. rotatable shaft mounted in fixed parallel relation to the printing roll and having a scale therealong, a pair of arms movable along each of said shafts, and means for securing said arms in adjusted position to swing with said shaft when the latter is rotated, said arms carrying pins adapted to be inserted in holes in said printing plates to carry the same into position against the printing roll when said arms are swung thereagainst.

4. In a multi-color printing press including a plurality of printing rolls and a flexible printing plate for positioning on each roll, each plate having a pair of positioning holes therein, means for effecting proper registration of said printing plates with respect to each other comprising a graduated shaft xedly mounted for rotation alongside each printing roll and parallel thereto, a pair of arms adjustably mounted on each shaft for movement therealong, means for securing said arms to said shafts in their adjusted positions with reference to said graduations, and pins carried by said arms for insertion into the holes of a printing plate to carry the plate upon swinging movement of said arms into the proper position on the corresponding printing roll, where said plate may be adhesively secured before withdrawing said pins.

5. In a multi-color printing press including a plurality of printing rolls and a flexible printing plate for positioning on each roll, each plate having a pair of positioning holes therein, means for effecting proper registration of said printing plates with respect to each other comprising a graduated shaft fixedly mounted for rotation alongside each printing roll and parallel thereto, a pair of arms adjustably mounted on each shaft for movement therealong, means for securing said arms to said shafts in their adjusted positions with reference to said graduations, pins carried by said arms for insertion into the holes of a printing plate to carry the plate upon swinging movement of said arms into the proper position on the corresponding printing roll, where said plate may be adhesively secured before withdrawing said pins, a graduated wheel fixedly secured to one of the printing roll shafts, a stationary pointer associated with said wheel and gears forming a positive driving connection between said rolls, whereby when the one printing roll is set in predetermined angular position by reference to said graduated wheel and pointer the other rolls are properly positioned automatically. l

6, In a. printing press including a printing press roll and flexible printing plates adhesively seoured to the face of said roll, the combination with such roll and plates of means for indicating the proper angular adjustment of said plates and means for temporarily supporting said plates as the same are successively moved toward said roll to properly position said plates circumferentially of said roll.

7. In a multi-color printing press including a plurality of printing rolls and employing flexible printing plates adhesively secured to the faces of said rolls, the combination with such rolls and plates of a fixed marker, a wheel having graduations thereon cooperating with said marker for indicating the proper angular adjustment of all of said rolls simultaneously and means for temporarily supporting said plates as the same are moved toward 'said rolls to plates circumi'erentially of said rolls to eilect exact registration between the imprints of the plurality of printing plates on a web to be printed.

8. The method o1' eiecting proper registration of imprints when printing on a printing press, which comprises providing each printing plate with correspondingly positioned holes, mounting said plates by means of said holes on swingable members pivotal about a fixed axis parallel to said roll, swinging said members to bring said plates into contact with said roll surface and seeming said plates in place before withdrawing said swingable members.

9. The method of effecting proper registration oi imprints when printing on a multi-color printing press, which comprises providing each printing plate with correspondingly positioned holes, turning said rolls into the proper angularly indexed position, mounting said plates by means of said holes on swingable members pivotal about a ixed axis parallel to said rolls, swinging said members to bring said plates into contact with said roll surfaces and adhesively securing said plates in place before withdrawing said swingable members.

JOHN F. HAWLEY.

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