US2334821A - Printing press - Google Patents

Description

NOV. 23, 1943. LE 2,334,821

PRINTING PRESS Filed March 26, 1942 2 Sheets-Sheet l Nov. 23, 1943. J. F. HAWLEY PRINTING PRESS Filed March 26, 1942 2 Sheets-Sheet 2 J 25 g g5.

Patented Nov- 23, 1943 UNITED STATE s- PATENT oFFicE ramrmc rnnss John F. llawley ltiverslde, in.

Application March as, 1942, Serial No. 438,303

6 Claims.

- which are provided on their backs with a pressure sensitive adhesive coating. The difliculty 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 aflixed, so as to indicate the proper position for the plate, butthat 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 angular indexing arrangement, which may comprise a wheel carried by at least one of the printing roll shafts and a stationary pointer cooperating with graduations or indexing marks on the wheel, or the marks can 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 sufficient to bring all of the printing rolls into the same angular relationship. a

I have now found that long flexible printing plates supported solely by the spaced ends of swinging arms for positioning on a printing roller tend to belly or sag between the ends of the arms. Further, movement of the swingable I arms lengthwise of a printing roller into proper the printing plate must be entirely separatedv from the surface of the printing Iroll between successive steps of ailixing the plate to the surface of the roll.

In accordance-with the invention described and claimed in my 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 difierent 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. According to my patented invention I utilize the perforations. of the printing plate for properly positioning the plate both angularly and circumferentially of the printing roll. This isaccomplished 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 he 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, my patented invention provides an registering position for a flexible printing plate on the roller may be cumbersome andadds to the arm swinging steps separate steps for positioning the arms lengthwise of the printing roll and for subsequently withdrawing the arms to a position outside the printing roll ends to avoid interference with access of the form rolls to the pri tin p e According to my present invention, each pair of positioning arms is swingable at fixed points outside the printing roll ends and the ends of the positioning arms are connected by a cross bar. This cross bar is slotted longitudinally and is also provided with graduation marks distributd lengthwise of the'bar. Pins or the like may be secured in the slot transversely thereto at any desired locations for supporting a flexible rubber plate in registration with other plates supported by like pins on similar cross bars carried by the ends of other swinging arms pivoted outside the ends of the other printing roll of the same printing press.

In this improved construction, the cross bar supports a flexible rinting plate throughout the plate length to prevent sagg and Further, the swinging arms need not be moved lengthwise of the printing roller in order to bring a printing plate carried thereby into proper registration. The printing plate is rather originally placed on the cross bar in registering position as indicated by the graduation marks on the cross bar, and the arms are merely swung against the printing roll and then swung away there'- from after the printing plate has been transferred to the printing roll.

It is therefore an important object of the present invention toprovide a m'ulti-color printing press having improved means for applying to the printing rolls thereof adhesive backed flexible for applying such printing plates in registration with each other including arms swingable outside the printing roll ends and connected by graduated cross bars in which positioning pins may be disposed at proper locations for insertion into the holes of the printing plates tohold said plates temporarily as the plates are brought into contact with an adhesively secured to the S111? faces of the printing rolls.

Other and further object and features will be apparent from the disclosures in the specification and the accompanying drawings.

On the drawings: I

Figure 1 is a side elevational view, with parts shown intransverse cross section, 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 flexible printing plate to a printing roll.

Figure 4 is an enlarged fragmentary elevational front view of a plate positioning arm and cross bar. v v

Figure 5 is an enlarged end view of a positioning cross bar carrying a flexible printing plate. v Figure 6 is a plan view of a flexible printing plate. a

In Figure 1 is illustrated a multi-color printing press of more or less conventional construction, including a stationary frame ID on which are mounted printing rolls ll, l2 and I3 and cooperating backing rolls l4, l5 and IS. A movable frame I! is suitably mounted upon a pair of tracks [8 for movement thereover by means of a rack l9 and. pinion 20. Said frame l1 carries the usual form rolls 2| and ink distributing rolls 22, which are adapted, when the frame I1 is moved up into association with the stationary frame ID, to apply the ink, color or the like to the printing rolls II, [2 and [3.

A roll of paper 23 is adapted to be mounted upon the stationary frame It]. 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. 6), which may' be formed of a laminated rubber composition base 28 having raised printing indlcia 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. Proper registration is equally important when the finished print is made up of a plurality of single color imprints. As an aid to effecting proper registration in accordance with my present invention, I provide a pair of holes or apertures 30 and 3| anywhere on the printing plate, for

frame l0. Since all of the shafts and their associated parts are identical, only one need be described.

'and 36, as at 43,

On each of the shafts 32 is mounted a pair of arms 35 and 36. Each of said arms includes a hub or collar portion 31 which encloses the shaft 32 and which is key'ed thereto to fix the arms lengthwise and peripherally of the shaft by means including keys 38. Each of the arms 35 is provided with an inner curvature 39 that conforms generally with the curvature of the printing roll, in order that the'ends of the arms may be brought into fairly closely spaced relationship with the surface of the roll. In order to make the arms lighter in weight, while still preserving their rigidity, spaced openings 40 may be pro vided along the length of the arms.

The free ends of each arm pair 35 and 33 support a cross bar 42 rigidly aifixed to the arm ends by any suitable means. This cross bar 42 is preferably curved transversely into semi-circular cross sectional form." The cross bar 42 is further slotted lengthwise between the arms II As shown in Fig. 5, studs 44 having a flat cap 45 with a lug 46 projecting therefrom may be inserted in the slot 43, with the fiat cap 45 seated on the outside of the cross bar and the lug projecting toward the press roll. A nut 41 serves to hold the stud in any desired position lengthwise of the cross bar.

The cross bar 42 may suitably be one half of a pipe sectioned lengthwise and slotted longitudinally at the bottom of the cross sectional curvature.

As best shown in Fig. 4, the cross bar 42 is provided with graduations 48 distributed lengthwise thereof. The graduations 48 need be in no particular units of measurement, but should be sumciently closely spaced to enable exact registration of the printing plates lengthwise of the printing rolls. Further, a pointer 49 is associated with each stud 44, being formed, for instance, by a pointed extension of the stud caps 45, to assist in setting the studs 44 in the desired position lengthwise of the bar 42.

Each lug 46 is of the same diameter as one of the holes 30 or 3 I. In positioning a printing plate 21 against the surface of a printing roll, such as the roll I I, the studs 44 are first placed in proper registering position lengthwise of the bar 42 as indicated by the pointers 49 on the graduations 48. The studs are, of course, properly spaced to be received in the holes 30 and 3! Two or four or more studs may be provided, to permit positioning one or two or more printing plates side by side on the same printing roll. The printing plate or plates are then suspended from the lugs 46, with the adhesive-backed plate side facing the printing roll. The arms 35 and 36 are then swunginto the position shown in Fig. 3, until the ends of the lugs 45 are in contact with the surfaceof 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 tioned about each of the printing rolls II, If and If, their center lines will obviously be spaced 120 apart about the circumference of the mils. In

has been positioned in place, the arms 35 and 85 this case, therefore, three graduation lines are lowered so as not to interfere with the ap- 5 spaced 120 apart on the wheel 5|, will be. emproximation of the rolls 2| against the printing ployed in the indexing operation. Similarly, if rolls. The lower two arms 35 are shown in Fig. l there were six printing plates to be positioned on in such' a non-interfering position.

Since the printing plate 21 is supported length-- wise by the cross bar 42, the plate will not belly or sag between the lugs It. Further, the arms 35 and 38 need not be moved lengthwise of therolls II.

In order that'the several printing rolls II, II and I3 may all be adjusted to the proper angular position, I provide an indexing mechanism comprising a wheel 5| secured to an extended end of one of the printing roll shafts, such as the upper shaft 52, and a stationary arm 53 secured to the frame ll as at 54 and having a straight edge 55 for registration with one of the indexin marks 55 on said wheel 5|. Since the several printing rolls II, II and I3 are positively driven by a common train of gears, including the gears 55 on the ends of said printing roll shafts and idler gears 51, a setting of the upper printing roll l| 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" I! is tumed to the proper setting on the indexing wheel 5|, the first set of printing plates positioned in place on the respective printing rolls ll, I2 and I3, and then the upper printing roll II is turned to the next indexing position on the wheel 5| at which a second set of plates is to be positioned, and so on until all of the sets of plates have been afllxed to the printing rolls. It is preferable to have the diameter of the wheel 5| about twice that of the printing rolls, so that an error, say of in the setting of the wheel 5|, results in an error of only one-half as much; namely, %4", in the positioning of the printing plate circumferentially of the printing roll. I

Although no means is shown for turning the upper printing roll into its indexed position, it will be understood that this can be done manually through the wheel 5| itself. 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 a taskto turn all of the printing rolls through the train of gearingthat serves to drive them. This train of gearing is not shown in toto, but is indicated by gears 65 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 l4, l5 and it. Because of this common train of gears between the printin rolls ii, I! and i3, the setting of the upper printlng roll II by means of the indexing mechanism, consisting of the wheel 5| and pointer 55, serves to index the other printing rolls l2 and I3 to the same angular relationship. It will be appreciated, of course, that in adjusting the printing rolls to the same angular relationship, the indexing wheel 5| 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 sufllcient backlash in the train of gears to give rise to an error in the indexing.

If there are three printing plates to be posi- 75 tion,

each printing roll, six equally spaced graduation lines 55 on the indexing wheel 5| would be'. brought successively under the straight edge I! of thepointer arm 53.

v It is .thus possible, by the use of my improved indexing mechanism, to insure proper registration'of the printing plates in a multi-color printing press, and. to do this with aminimum of labor and effort and without having flexible plates. belly or sag while being brought into registering position. 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 on this invention otherwise than necessitated by the scope of the appended claims.

I claim as my invention:

1. In a printing pressincluding a printing roll on which printing plates are adapted to be positioned, means for releasably engaging said plates at stations spaced from said rolls and for conveying thus engaged plates to said roll in proper registration, said means comprising swingable arms, a member connecting and swingable with said arms and having graduation indicia associated with said member, and plate engaging means securable in said member at positions determinable by reference to said indicia for applying the plate to the printing roll.

2. In a printing press including aprinting roll on which printing plates are adapted to be 40 positioned, means for releasably engaging said plates at stations spaced from said roll and for conveying thus engaged plates to said roll in proper registration, said means comprising arms swingable outside the printing roll ends, a cross bar connecting and swingable with said arms into proximity with said printing roll .and provided with graduation indicia distributed lengthwise of the bar, and plate engaging means carried by said cross bar and movable lengthwise thereof 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 on which printing plates are adapted to be positioned, means for releasably engaging said plates 'at stations spaced from said roll and for conveying thus engaged plates to saidroll in proper registration, said means comprising a shaft carrying arm swingable outside the printing roll ends, a cross bar connecting and swingable with said arms into and out of proximity with said printing roll and provided with graduation indicia distributed lengthwise of the bar, and pins capable of being adjustably secured on said bar and adapted to be inserted in holes on said printing 5 plates to carry the same into position against the printing roll when the arms and cross bar are swung thereagainst.

4. In a multi-color printing pressincluding 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 releasably engaging said plates at stations spaced from said rolls and for conveying thus engaged plates to said rolls in proper registrasaid means comprising a shaft fixedlymounted for rotation alongside each printing roll and parallel thereto, a pair of arms, secured to each shaft outside the printing roll ends, a cross bar connecting said arms and swingable therewith on rotation of said shaft and provided with graduations distributed lengthwise 01' said bar and pins carried by said bar adjustably secured theretoior insertion into the holes of a printing plate to carry the plate upon swinging movement of said arms and cross bar into the proper position on the corresponding printing roll, where said plate may beadhesively 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 releasably engaging said plates at stations spaced from said rolls and for conveying thus engaged plates to said'rolls in proper registration, said means comprising a shaft fixedly mounted. for rotation alongside each printing roll and parallel thereto, a pair of. arms securedto each shaft outside the printing roll ends, a cross bar having a semi-circular cross section and slotted lengthwise between said arms as well as provided with graduation marks distributed lengthwise of the cross bar, pins having threaded portions insertable into said slot and provided with flanges capable of being seated on the outside or the cross bar, said flanges being formed with pointers for indicatingthe position of each pin with reference to said graduation marks, and nuts capable of being threaded on the inserted pin ends to secure the pins in any desired position on said cross bar, said pins being capable of insertion into the holes of a printing plate to carry the same.

6. 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 releasably engaging said plates at stations spaced from said rolls andfor conveying thus engaged plates to said rolls in proper registration, said x means comprising a pair of arms and a graduated cross bar connecting the arms swin'gable to and from the surface of each printing roll, pins adapted to be inserted into the positioning holes in the plates to hold the plates temporarily and means for securing said pins. to said bars for holding flexible printing plates thereon in proper registration lengthwise of said bars as indicated by the graduations thereon.

JOHN F. HAWLEY.

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