US2663255A - Multicolor proof press - Google Patents

Description

Dec. 22, 1953 J R. PARRlsH 2,663,255

MULTICoLoR PROOF PRESS Filed March 3,v 1951 2 Sheets-Sheet l INK/NG NATHAN/5M gz llllllI/Illll/l/A- Dec. 22, 1953 J R. PARRlsH 2,663,255

MULTIcoLoR PROOF PRESS Filed March 3, 1951 2 Sheets-Sheet 2 In merz 207'. JR awa @Z2 Pa zfz's,

Patented Dec. Z2, 1953 MULTIOOLOR PROOF raEss J Russell Parrish, Des Moines, Iowa, assignor to HMeredith Publishing Company, Des Moines,

Iowa, a corporation of Iowa Application March 3, 1951, Serial No. 213,773

- Claims.

I This invention relates to a multi-color proof press for use in the proong of curved rotary 4press plates, although the invention is not necessarily limited to that use. This particular application is a continuation-in-part of'application Serial No. 51,400, filed September 27, 1948, now abandoned. 1

Large rotary presses for printing color sheets may, for example, print hundreds of thousands of the same color sheet on one run. These large presses take considerable time to set up for printing, and this so-called make-ready time may take one hundred or more man hours before the press can be started. This is expensive not only because of the time in labor, but also because the press is not producing during the make-ready time. Furthermore, if there is anything Wrong with one or more of the printing plates, it does not show. up until a run is started, and thereafter if even a single plate must be removed for co1'- rection, the press must be shut down all during the time ,the correction is made. For the above reasons, proof presses have been devised to test the plates prior to their being disposed on the main press.

, The available proof presses also have certain disadvantages. Under present methods of curved plate proofing, a single color proof is pulled by hand of each plate. Usually these are in black ink, so that neither the color may be proofed, nor may the nalresult in two, three or four colors beseen until the main press is run.

It is thereforel an' Object oi the invention to provide an improved multi-color press which may be used as a `proof press.

It is also an Object of the invention to provide a multi-color proof press in which plate register may be determinedpror `to sending the plates to the press'roo'm and prior to attaching them to the ymain press. Therefore, if certain plates must be cut and leveled, this may be done in advance, thus reducing the make-ready time on the main presses. If necessary to make new plates, they may be ordered when proofed instead of waiting until the run is started.

It is a further object of the invention to provide a multi-color proof press on which the interchangeability of spare plates with regular sets may bev checked in advance of press runs, thus saving press time during a run.

It is an additional object of the invention to provide a multi-color prooi press in which the results to be obtained from the use of certain inks, the comparative tone intensities for each color and the selection of the proper underlay may all be checked in advance of placing the plates on the main press.

It is a further object of the invention to provide a multi-color proof press on which perfect register checking may be obtained on a plate proof, since the sheet does not leave the gripper bars of the impression cylinder until all the colors are printed. Furthermore, the wet inking process used on multi-color high speed presses may also be used on a proof, thus obtaining close to true press conditions on a proof press.

It is a further very important object of this invention to provide a multi-color proof press in which the colors are printed in proper sequence, and where the proof is printed as the finished product will be and not reverse.

It is still a further object of this invention to providea multi-color proof press which is adaptable for `continuous operation and small production runs.

It is a further important object of this invention to provide a multi-color proof press having a relatively large size impression cylinder.

With these and other objects in view, my invention consists in the construction, arrangement and combination of the various parts of my device whereby the objects contemplated are attained, as hereinafter more fully set forth, pointed out in my claims and illustrated in the accompanying drawings wherein:

Figure 1 is a diagrammatic view of a multicolor proof press showing the relative position of the plate cylinders and impression cylinder; and also showing shelves over which sheets are delivered tov and received from the impression cylinder when this multi-color proof press is used as a job press for continuous Operation or small production runs;

Figure 2 is a schematic View of the grippers on the impression cylinder and the actuating mechanismtherefor, and is taken looking upwards on Figure 1 from beneath the impression cylinder, with the feeding shelf removed;

Figure 3 is a diagrammatic view of the grippers just seizing a sheet to be printed; Y

Figure liris a diagrammatic view of the grippers "just opened and with a printed sheet being dis- Figure '7 shows the tumbler just before the grippers are opened;

Figure 8 shows the tumbler just after the grippers are opened;

Figure 9 is an enlarged side elevation of the multicolor prooi press shown in Figure l, illustrating a typical automatic operating mechanism and cam arrangement for .reciprocating the tumbler `actuating pins when thisi proof press is being used as a job press;

Figure 10 is another View of the operating mechanism for the tumbler actuating pins and is taken on line llli 0 of Figure 9; and

Figure 11 is a detailed drawing of a cam shown in Figure 9. Y

Referring to the drawings, the following general observations are true with respect to the invention shown therein. The-l impressionfsuriace of an ordinary proof press covers most, if not all, of the surface of the impression cylinder. On the other hand, it will be noted that inmy invention the impression surface'covers no more than one-half of the impression cylinder surface, and therefore the'impression cylinder 'mustbe larger relative to ordinary proof ypress impression cylinders.

A Vfew of the many advantages of 'having a large size impression cylinder rwill now be set forth. -With a large impression cylinder, there is increased time of contact of the printing plate with the impression surface and this effects better transfer ofthe ink. This increased time of contact is known as a period of dwell and the results of such increased period are the same as would beattendant with a slower speed of'rotation' of the impression cylinder. AThere is also an increasedV area of contact' thus making it easier to control the amount of impression, especially in localized areas. The interface force between (the plate cylinder and the impression cylinder 'lmay be decreased thus more closely" simulating the desired kiss impression. A further' result of the reduced interface force is' a decrease' inthe wear ofthe printing plates and vital press parts, also due in part to reduced shock. Furthermore, there is less humping of plates, better matching lwith engravers proofs (which are vmade hat) and a decrease of pull of ink from the plate cylinder.

Furthermore, if the same peripheral speed is maintained there vis a decrease inthe centrifugal force upon the paper as the 'rotary speed `de creases. The paper also lies better on ailarger diameter cylinder and fewer wrinkles result. llt will also beevi'dent that larger lsize impression cylinders provide more accessibility to rollers,

plates andpacking,` with' af resultant` lower cost ofv operationY and Vlowermaintenance cost.

' Still further,` small impression cylinders tend to bow as does a loaded beam dueto the 'uneven and uncontrolled.interface pressurev between the plate cylinders and the impression v cylinders. Small diameter cylinders, forced-to operate at higher. speeds, valso have atendency to-fwhip', especially when used with unbalanced plate cylinders. Both of these undesirable features are obviated by the vuse of a large size impression cylinder.

Although the exactposition of the plate cylinder or cylinders around the impression cylinder is .unimportant from.the standpoint of many of the principles involved herein, the plate cylinders must be positioned so as not to interfere with the impression cylinder taking on fresh sheets or discharging printed sheets. The positioning of the plate cylinders with respect to the points der, the :inkingror form. rollers may be engaged and disengaged by means of a cam (not shown) on the plate cylinder in a manner well known in the art.

'in ythe Adesign shown in the accompanying drawing, the. surface of the plate cylinders are 'each divided'intothree equal sized portions or segments. The'. impression cylinder is divided into two equal sized portions or segments, each ofwhich latter. portions are equal in size to the plate cylinder portions. The peripheral speed of all three cylinders is the same. It is therefore obvious that the gearingratio between the .impression cylinder and the plate cylinders is other than 1:1. It-will further be 'noted that the'ratio between the impression cylinder diameter and the diameter of the plate cylinders is an a'liquant number. In other words, the ratio isl such that when the smaller number'is divided into the larger number, a fraction is alwaysleit over. This provides that the color plates on the'plate cylinders successively contact one andthe same area on the impression cylinder, whereby'a Ysheet of paper placed on this particular area willreceive successive imprints of diiferentcolorsVA always in theA same predetermined sequence.

It will be recognizedthat theratio .between the circumference of the impressioncylinder and the circumference of the jplate cylinderi's'the same aliquant number as the ratio Cif-"the diameter of the impression cylinder andithe .diameter of the plate cylinder, since thecircumference ofS a cylinderlis merely vr times the diameter. Since segments of the impression cylinder andplate cylinder must repeatedly coincide in predetermined sequence during a printing run, the circumference'may be defined in terms of these segments and a unit of circumferential length will' be dei-ined' in terms of an impression surface on which Athe sheet to bejprinted is mounted, or in terms of a plate surface'which carries the ink. This unit of circumferential length is an aliquot part offboth the circumference of the impression Vcylinder'and the circumference of the plate cylinder. In Vthis specification, the relationship of impression surfaces to plate surfaces'will' be taken upv and described,

as such relationship is simpler than a discussion of the 'relationship of 'the diameters of the vimpression and` plate cylinders.

In the normal operation of Yproof presses, only a'few prints are'imlled,` corrective workv is accomplished,V and then'pos'sibly a few more proofs made. The sheet upon which Ythe proof is printed is usually fed to the impression cylinder by hand overa feed board above the yimpression cylinder. rIhe grippers are usually operated by means of a foot pedal.

The impression cylinder is then tur-ned the necessary number of times to complete a cycleand complete the printing of .the proof. The. operator then reaches underthe .feed lboard to grasp the lower edge of the printed sheet and then releases the grippers.bypressingrthe lfoot pedal.

In Vthe description of this invention, it will `be noted that thesheet .upon which the proof is to be. printedis fed to the impression cylinder over a. feedboard or shelf below the impression cylinder. When the elements of this invention are used solely as a proof press it makes no difference whether thesheets are fed to the bottom or top of the impression cylinder. But when this invention is used as .a job press, it is necessary that the printed sheets be discharged face up so that 4 the ink not be smeared, and, therefore, the sheets are fedto the bottom of the impression cylinder.

In this application the proof press, modified with automatically operating grippers so as t'o be usable as a job press, will be described. The description Vof the pedal mechanismfor'` operating the grippers, which pedal mechanism wouldy probably be used when/this invention is used: only for proofing, will be omitted as itis welllknown in the art. i

Referring now in particular to the drawings, there is shown in Figure Y1 a multi-'color proof press comprising a rsingle impression cylinder IIJ and two platecylinders I2 andV I4. The impression cylinder I8 and plate cylinders I2`and I4 are geared together'to rotate at Vthe lsame peripheral speed. 'I'he impression cylinder I0 isv of smaller diameter than are the plate cylinders I2 and I 4;

The ratio of the circumference of each plate cylyinder I2 and I4 to the circumference of the impression cylinder I0 isf 3:2. The impression cylinder I Il is providedV with one impression'segment or surface I6 and a single set of grippersi 8. The impression surface vI6 on impression cylinders I0 extends substantially over one-halfV of the circumference of cylinder I0. The remaining portion or segment of the circumference of impression cylinder I0 is recessed or undercut .at 20; The grippers I8K are mounted within the recessed portion 28 and thus itis not `necessary to provide an additional recess space wherein the grippers I8 aremounted. Y L; i' v The plate cylinder I2 is provided with twosegments for printing plates ,'22 and 24,: each of which is substantially of the same arcuate length as impression surface I6.v An,:undercut or recessed portion or segment v26 is provided between printingplates 22l and'24 and is also of substantial-ly the same arcuate length as impression surface I6. The plate cylinder I4 is similar to plate Y cylinder I2 and has twosegments` for` printing plates 28 and 36 thereon, with an; undercut or recessed segment orrportion 2 9 therebetween.

v Each of the printing platesi22, 24, 28 and 3l) is adapted to print ,ardierent color inkona sheet to be printed, which is carrieduponimpression surface I6. Forlthe purpose of this description. it is assumed that the plate 22 applies the yellow color, plate 2li-blue, plate'28-red, and plate 30- black. Inking apparatus is provided for applying ink to the surfaceV of the printing plate and is schematically illustrated at 32,V 34, 36v and 38. The manner of applying ink to the printing plates from the inking apparatus 32, 34, 36 and38 is well known in the art and will not be described herein, as their operation does not form part of the invention.

A pair of shelves 40and 42 are providedadjacent the impression cylinder I6 as shown in Figure 1. The sheets to be printed`4I1are fed along shelf l4I) to the point where they aregripped by the grippers I8 and the shelf r42 is'v positioned where it will receive the sheets that are printed after they are discharged from the impression surface E6 upon the opration of the grippersv I8 ,to an open position. Y Referring now more particularly to the grippers, a plurality of the grippers I8 are mounted 'on a shaft 44, which shaft is journaled at points 46 and 48, as illustrated in Figure 2; One end of the shaft 44 extends beyond the point where it is journaled, as at 50. This extended end 50 of shaft 44 has la tumbler 52 Xedly mounted thereon. The opening and closingof the grippers I8 is accomplished by arcuately moving the tumbler 52 about the axis of shaft 44, resulting in the arcuate movement of shaft 44, which is fixedly secured to the tumbler 52. Figures 3 and 4, respectively, show the grippers in the closed and open position and indicate the range of arcuate movement of shaft 44 in accomplishing the gripping and releasing of the sheet t0 be printed.

The tumbler 52 consists of a pair of spaced fingers 54 which form a pocket 56 therebetween, which is located to one side of the point of securement of tumbler 52 to shaft 44, and a second pair ofv fingers 58 bounding a pocket 60 located diametrically opposite the pocket 56.

When the impression cylinder I0 rotates, the gripper shaft 44 and tumbler 52 rotate with the impression cylinder ID. A pair of tumbler actuating pins 62 and 64 are provided to actuate the tumbler 52 at the proper times to close and open the grippers I8 which pins are best shown in Figures 2, 9 and 10. These actuating pins 62 and 64 are normally withdrawn from the path of the tumbler 52 as it rotates with theimpression cylinder I 0. At desired intervals' these pins 62 and 64 are thrust into the path of tumbler 52 to be engaged by tumbler 52 and to cause the tumblers to operate the grippers I 8 to open or closed position.

A portion of the frame of the proof press is designated at 68 and upon this frame the tumbler actuating pins and actuating mechanism therefor are mounted. Referring more specifically to Figures 9 and 10, the pins 62 and 64 are mounted in the frame structure 66 and are normally biased to a withdrawn position, as pin 62 is in Figure l0, as shown in full lines. The position when extended is shown by dotted lines, andis indicated by 62a as shown in Figure l0. The pins 62 land 64 are biased in the withdrawn position by means of springs 68 which are seated in pockets 'I0 in frame 66. A ange ' l2 on'each pin 62 and 64 cooperates with the spring in'a well known manner. The pins 62 and 64 are thrust forward by means of bell cranks 74, which in turn are actuated through push rods 'I6 which have cam followers 'I8 at one endthereof rolling over the surface of cams and 82. The bell cranks 74 are pivoted upon pins 'I5 mounted in ears 15a which project from the frame 66. The push rods 'I6 are slidingly journaled in blocks 'I1 which project from frame 66. e

The springs 68 serve to 'maintain the cam followers A'I8 constantly in engagement with the surfaces of cams 86 and 82. The cams 86 and'82 are mountedv on a shaft upon which one of the plate cylinders I2 or I 4 is mounted. As shown specifically in Figure 9. the shaft 84 is the'shaft upon which plate cylinder I2 is mounted.

, The location of tumbler actuating pins 62 and 64 is of great importance, for they must be positioned slightly before the point at ywhich the grippers I8 are closed or opened. It can be seen by referring to Figures, 6, '7 and 8, that, for eX- ainple, in the-closing of the grippers I3 shown in Figures5 and 6, the tumbler 52 engages the pin at a point before bottom dead center, where, theoretically, the grippers are to close on the sheet to be printed. Then, as the tumbler 52 continues to rotate counterclockwise-about the center of impression cylinder I6, the pin 62 being xed causes the tumbler 52 to rotate clockwise about the axis meegaat Operation. of the multi-colorprooj press n the voperationfof the'multi-cclorf'proof press, let us-refer to Figurewhere' the tumbler, 52.is positioned so thatthegrippers :fila-reopen and the pin S2 is thrustv forward intothe path of `,the tumbler -52lsoas to actuate :the tumbler --52 -to .close thegrippers i8. The tumbler `tizfis sorpositioned that the Afingers .54, pass over lthe pin.y 52,- `causing the .pin-62 to enterthepocketf56. The pin being l fixed. engages. the 4.finger 54-and causes the tumbler 52 yto rotatefclockwise-about the-axis of gripper sha-ft 44 yasithe tumbler moves past the pin 62 in'counterclockwise' direction. All the time that the tun'iblerr52r ismoving past the pin 52, the pin is :moving deeper :into pocket 5g. The pin* 52 and the gripper shaft i4 areeclosest to each other when they are located'upon-aV radius through the'center `of rotation of theirnpression cylinder 1U,

As the tumbler-52 continues its counterclockwiserotation.` about thefaXisof-athe impression cylinder the pin causes the clockwise rotaticnof the tumbler 52 and'thewshaft` 44' about-thea-Xis of shaft 44, thus closing the 'grippersf :13. v"Ilhe pin 52: also serves to 4position the tumlzvier'sovthatV the vfingers 58 point in :thedirecticn necessary to grasp tumbleiactuating pin Gflrwhen the sheet thatvis printed `is to `be discharged. Itlwill lkie-noted that the attitude of the tumbler-52 as it leavespinrZ, asshownin-:Figure 6J is the same fas. the attitude ofV the tumbler 52 when it is' just grasping. pint!! as shown in Figure "7, for the purpose of discharging the printed sheet of paper.

v After the 'grippers .I 'ihave seized a sheet'to vbe printed, 'the sheet wllhaveprinted on it. the color .which is carried l by printing plate'22f/andthere- .aftercduring thefrstrevolution ofthe impression cylinder; the sheet will also :haveprinted on itz-the -color carried by nprinting plate' 28. yAs* the impression cylinder l0 continues -to lrotate,1the

recessedsuriace Zil will register witlrtherecessed space 26 and then laterwith the'recessedsurfaee 29. Upon thesecond rotation of the 'impression cylinder 10,; the Ysheetv being printed 'will engage the printing plate 2d and then engage theprinting-plate 30. TheY recessed surface`f20 Auponthe second revolution willv register with the printing pla-te 22 and then the printing plate 28, and thus there will be no transfer of ink from theseV plates to-any surf-ace on the impression cylinder during this second revolution.

During the second revolution,v the sheet that is being printedmay'be discharged from the cylinder, but in the preferred embodiment shown, vthe sheet is not discharged from the cylinder, as itis desirable that the sheet be maintained in -continuous, contact with the printing plates Vwithout any possibility of slipping therebetween. As the impression cylinder- I0 makes a third' revolution, the impression surface IG will first registerwith the sr'ecessedfpoiti'on '26 fa-nd? then with the f recessedpo'r'tion 2li,V during which time noportion 'of theY sheet 11,6 will-bein engagement withA any-of the printingplates onthe yplate cylinders. As'the tumbler approaches top dea-d center of the impression cylinderv Ill-during the third revolution, the `pin -64 -isthrustl forward and the tumbler 52 engagesA this .pin 64, opening the grippers and discharging thep'rintedsheet from the cylinder onto shelffdZ.

The tumbler'52 vis moving counterclockwise aboutthe axis .ofthe impression cylinder, and whenfftumbler52 .engages pini 64, the tumblerv 52 is caused?to:rotatef-counterclockwise about the axis :.of shaftr,44,'thus= opening the grippers I3. This counterclockwisemovement of tumbler 52 about the axis of shaft `Ml is illustrated in` Figures'. Tand-.18,1 the tumblermoving from the position .in Figure '7l tothe position in Figure 8.

'Thetumbler52 when it leaves pin 64 is in the attitude where the 'ngers 54 are adapted to seize v`lthe pin'` 62 asA shown in Figure 5, whereupon they entire' cycle is again gone through. The fact that .an .entire cycle maybe continually repeated permits the: usesof. this proof press asa production press for:`- small runs.

Whilethe impression cylinderv Hl is making threerevolutions, the-plate cylinders l2 and ld aref'making'two revolutionsduring a complete printing cycle of the proof press. Since the cams aremounted on the shaft of one of the plate cylinders, namely, jplate-cylinder I2, `the pinsV B2 and 64.wil1 be thrust forward twice during each complete cycle of thev running of the proof press. Howeverythere'- 'isr no `possibility of inadvertent engagement ofthe tur'nblerr 52 with either of' the pinsi62 or 54, because while the pins `F52 and 64 arethrust'iiorwardtwice 'during 'a cycle, they are in the correct position for actuation of the tumblen 52 only: once'during--each cycle. "Upon their. being thrust iforwardthe second time during'the .cyc1e,tur'n`bler v52 isvapproximately 180 away fromtheroperating position where the pins are'being.'thrustY forward, and thus the pins 62 and Bd'will not actuate the tumbler 52.

- 'iTheztumbler' 52 Tis both'opened andclosed withinapproximately of'rotation-of the impressioncylin'der. The tumbler is opened just before thefenduofxone cycle and, as it moves from approximatelysbottom dead centerto approximately top dead center, it'is actuated by pin 62 for thebeginning `ofthe vnext cycle. Thereafter, the pinsgidonot'operate the tumbler until the end of'the-cycla-'whenthe same procedure is repeated. "Thecamfas shown inFigure l1, has a portion lirwhich';maintainsil 'the corresponding pin in a fullyjorwardposition rwhilethe impression cylindertrotates about 30. The total enlargedportioniofifthecamris limited so that the pins are not partially thrust forward at any time when they may 4inadvertently trip thetumbler 52.

vSome changes may bev made in the construction and arrangement of the partsy of my device withoutidepartingv` from the real spirit and purpose-"of my invention-and it is my' intention to coverby my'V claims any modified forms of structure 'or'use of mechanical equivalents which may bereasonably included within their scope.

I claim as kmy invention:

1. A multi-coloredV printing press comprising a single Vrotatable impression cylinderand at least one rotatable plate cylinder each having a plurality of equal: segments the Vsur-faces thereof adapted :to registerftangentially as. the cylinders are rotated, the peripheral length of thegsurface ofthe impression and plate cylinders'eachr being an aliquot multiple of the lengthof the segment, the'peripheral length lof said impression cylinder comprising an even number of said segments and that of each plate cylinder'including an odd-number of said segments, means for rotating said impression and plate cylindersl at the. same peripheral speed, one-half ofthe number of said impression cylinder segments and one segment on each plate cylinder being recessed, whereby there is no peripheral contact between the im pression cylinder and the plate cylinders when a, recessed segment on one cylinder registers with any segment on another cylinder, the remaining segments of each-plate cylinder each adapted to carry a printing plate therein, the other onehalfy of the impression cylinder segments being impression segments adapted to carry thereon sheets toy be printed by printing platesV on'said plate cylinders, therecessed segments and the impression segments on the impression cylinder being arranged in alternate order, the number of segments on the impression cylinder and on the plate cylinders providing that during a full cycle of operation each impression segment registers once with each plate cylinder segment in the same predetermined sequence with said re` cessed segments on the plate cylinder being the last segments to soregister, and means for discharging a sheet 'from the impression segment after said impression segment has registered with each of the plate cylinder segments, whereby the sheet being discharged is completely free of engagement with any printing plate on the plate cylinder.

2. A multi-colored printing press comprising a single rotatable impression cylinder and at least one rotatable plate cylinder each having a plurality of equal segments in -the surfaces rthereof adapted toregister tangentially as thev cylinders are rotated, the peripheral length vof the surfaces of the impression and plate cylinders each being an aliquot multiple of the length of the segment, whereby the segments on said plate cylinders have their successive edges in juxtaposition, the peripheral length of said impression cylinder comprising an even number of said segments and that of each plate cylinder including an odd number of said segments, means for rotating said impression and plate cylinders at the same peripheral speed, one-half of the number of said impression cylinder segments and one segment on each plate cylinder being recessed, whereby there is no peripheral contact between the 1mpression cylinder and the plate cylinders when a recessed segment on one cylinder registers with any segment on another cylinder, the remaining segments of each plate cylinder each adapted to carry a printing plate therein, the other onehalf of the impression cylinder segments being impression segments adapted to carry thereon sheets to be printed by printing plates on said plate cylinders, the recessed segments and the impression segments on the impression cylinder being arranged in alternate order, the number of segments on the impression cylinder and on the plate cylinders providing that during a full cycle of operation each impression segment registers once with each plate cylinder segment in the same predetermined sequence, means for discharging a sheet from the impression segment when said sheet is disengaged from contact with all of said printing plates, the impression segment carrying said sheet registering with the recessed plate 'cylinder segments just before said sheet is discharged, and means for feeding a fresh sheet to be printed onto said vacated impression segment before said impression segment next registers with 'any other plate segment.

3, A multi-colored printing press comprising a single rotatable impression cylinder and at least one rotatable plate cylinder each having a plurality of equal segments in the surfaces thereof adapted to register tangentially as the cylinders are'rotated, the peripheral length of the surface of the impressionand plate cylinders each being an valiquot multiple of the length of the segment, the peripheral length of said impression cylinder comprising an even number of said segments and that rof each plate cylinder including an odd number of said segments, means for rotating Said impression and plate cylinders at the same peripheral speed, one-half of the number of said impression cylinder segments and one segment on each plate cylinder being recessed, whereby there is no peripheral Contact between the impression cylinder and the plate cylinders when a recessed segment on one cylinder registers with any segment on another cylinder, the remaining segments of'each plate cylinder each adapted to carry a printing plate therein, the other one-half of `the impression cylinder segments being impression segments'adapted to carry thereon sheets to be printed by printing plates on said plate cylinders, the recessed segments and the impression segments onv the impression cylinderv being arranged in alternate order, the number of segments on the'imp'ression cylinder 'and on the plate cylinders providing 'that during a full cycle of operation each impression segment registers once with each plate cylinder segment in the same predetermined sequence with said recessed segments on the' plate cylinder being the lastsegments to so register, means for discharging a sheet from thev impression segment after said impression segment has registered'with each of the plate cylinderl segments, whereby 'the sheet beingdisf` charged is` completelyfree of engagement withVK any'printing` plate on the plate cylinder, a feed-f ing station past which each impression segment passes as the impression cylinder rotates, said feeding station being positioned adjacent substantially the lowermost point of said impression cylinder, a discharge station adjacent substantially the uppermost point of said impression cylinder, both said feeding and discharge stations being positioned laterally of one side of a vertical plane through the axis of the impression cylinder, and the points of tangency of the plate cylinders with said impression cylinder being positioned laterally of the opposite side of said vertical plane.

4. A multi-colored printing press comprising a single rotatable impression cylinder and a plurality of rotatable plate cylinders, said plate cylinders each having a plurality of equal segments in the surfaces thereof adapted to register tangentially with a plurality of equal segments in the surface of the impression cylinder as the cylinders are rotated, the peripheral length of the surface of the impression and plate cylinders each being an aliquot multiple of the length of the segment, the peripheral length of thel said impression cylinder comprising an even number of said segments and that of each plate cylinder including an odd number of said segments, means for rotating said impression and plate cylinders at the same peripheral speed, one-half of the ii number of said impression cylinder segments. and one segment on each plate cylinder being re-v cessed, whereby there is no peripheral contact between the impression cylinder and the plate cylinders when a recessed segment on one cylinder registers with any segment on another cylinder, theV remaining segments ofeach plate cylinder each adapted to carry a printing plate therein, the other one-half of the impression cylinder segments` being impression segments adapted to carry thereon sheets to be printed by printing plates on said plate cylinders, afeeding station past which each impression cylinder segment passes as the impression cylinder rotates, the impressionvcylinder segments being so arranged that the recessed segments and the impression segments pass said feeding station in alternate order, the number of segments on the impression cylinder and on theplate cylinders providing that during a fullcycleA of operation each impression segment registers once With each plate cylinder segment in thesame predetermined sequence, the segments on the plate cylinders being so arranged that the recessed segment thereon is the last segment of each platecylinder to register Withthe impression segment.

during va cycle of operation, means fordischarging a sheet from the impression segment after said impression segment `has registered with each of the plate cylinder segments', whereby when Y the sheet is being discharged it is completelyk free of engagement with `any lprinting plate on the plate cylinders, and means for feeding a fresh sheet to be printed onto said vacated im,- pression segment before said impression segment next registers with any other plate segment.

5. A multi-colored printing press comprising a single rotatable impression cylinder and a pair of rotatable plate cylinders, said plate cylinders each having three equal segments in the surfaces thereof adapted to register tangentially with a pair of. equal. segments inthe surfaces ofthe impression cylinder as thecylinders/arev rotated, the peripheral length of thesurfaces of, the im.- pression 'and plate` cylinders each being an aliquot multiple of ,the .length of lsaidsegment lf2 whereby the. segments on af cylinder have their successive edges in juxtaposition, means for rotating said impressionY and plate cylindersy at the sameperipheralvspeed, one of said impression cylinder segments and one segment` on each plate cylinder beingvrecessed, Whereby there is noperipheral contact between the impression cylinder and the plate cylinders when a recessed segment on one cylinder registers With any segmenten anothercylinden the remaining segments of yeach plate cylinder each adapted to carry a printing plate therein, the other impression cylinder. seg'- ment being animpression segment adapted to carry thereon sheets to. beprinted by printing plates positioned, in? the remaining segments of said plate cylinders,the numberoi segments on thejimpression cylinder and on the plate cylinders providing that during a Jull cycle of operation each impression segment registers oncewith each plate cylinder segment in the samev predetermined `sequence With ysaid recessed segments on the plate cylinders being Athe last segments to so register, means for discharging a sheet from the impressionsegmenti after said -impression segmenthas-registeredwith each of the vplate cylinder segments; whereby When the` sheet isbeing discharged 'fitI is v completely free oi engagement with any printingplatefonth'e plate cylinders, and meansfor vfeedingla. fresh sheet lto be printed ontosaid vacated impression. segment before said impression segment next. registers with any other plate segment.,

J`.RUSSELL PARRISH.

Re?:ei-encesy Cited inytheiile of this patent UNITED STATES PATENTS smith May .24,193e

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