US1777785A - Printing apparatus - Google Patents

Description

F. J. coNNoLm/ PRINTING APPARATUS Oct. 7, 1930.

Filed Nov. 24, 192B 2 Sheets-Sheet l F. J CNNLLY Oct. 7, 1930.

PRINTING APPARATUS 2 Sheets-Sheet 2 Filed Nov. 24, 192B Patented. foot. 7, `1930i `ai)piiirion`ineanovemberarises,sensi Nazazijze, analisi eratiarimn Navembemsg 1927.y I

i This invention comprisesimprovements in n'intinrfa laratusfand isi: orimaril con-` cerned with means whereby 4large numbers oflcopies of an original are' producedbylthe i 5 aid of a number of reproductions of the original on Ione plate. I-Ieretofore, Vit has been the common practice tol adopt one oftWo methods. According to Vone `ofthese methods, a number of'litholgraphic impressions Were andwere attachedin suitable disposition to a suitable Y backing or carrier by the aid oi' which theywvere transferred to va larger plate ofthe desiredsize,f\vliich plate was mounted' upon a printing cylinder or flatbed. AoA cording to the other of these methods, a'num-V ber ofl photolitho impressions of `the original were produced `upon a zinc plate which VWas mounted uponlthe printing cylinder. -By these methods, Va number of prints were obtained per revolution ofthe printing cylinder, so "that the speed of productionvvas greatly accelerated. `These methods, however, were attended With certain defects andL diiiculties. For example, in one case accurate setting or registering ofthe several printing plates or surfaces was `di-mianded owingto the posi tion of each unit having been `determinedby hand and eye and not mechanically. 1 The `accurate setting or registeringlof such surfaces is all-important Where colour printing` is concerned, for it is essential that all copies should be properly spaced and `that in the case of more than one colour' appearingeach colour should `fall` into its correct position; In the vother case, special photographic plant had to be installedand a skilled photographer y Proposals have beenimade to produce large numbers of ip denticaljcopies bythe aid of a number of Areproductions obtained from the originalhytheoff-set process.` Tl'iisprocess the plates producedare more easily prepared A HFRANcisJosErH `coNNoIJIJz, on` BiLLAnnrcaYfnNeLNn :PnINTI- neznrrARa'rUsi-xp i i for printing from `owing to the absence of udine.

it Whichalwaysrollsup from a paper transfer.y The -saidjproposalshave included the taking up `oi' anumberofimpressions of C the originalgby an oE-set or transfer cylinder, l such -inipressions being subsequently transferred to a printing plate supported upon a flat` bed and the printing y plate `being then available forrthe printing of fanuinber of taken Afrom the original upon transfer paper reproductions at every operation. y Theob- )ectiof the present.inveiitioniisto improve upon these off-set methods and @to avoid de.` fects which it is believed have heretofore been responsibleforthe failure `of such methods tofbecome :a practical success.,

According to this invention, thel original iis mounted "upon a saddle `or carrier Which` is mounted ,with micrometer o r fineA adjustment upoiii'a" bed geared "With a lrotary olf-set or blanket cylinder so that relative reciprocatory motion can take place simultaneously `with "therevolutionof the olf-set cylinder,` and a plate cylinder is geared with theoli'fset cylin- `der and" isnadapted for the mounting of a printing plate which receives from the odset cylinder and can subsequently be used, or developed for use, as printing surfaces, trip mechanism may be operativeupon thev plate cylinder for intermittently.throwingit into and out of pressure relation with the off-set i or blanket cylinder, but so that the plate cyl` inder never loses its original angulanor circumferential setting relatively to the blanket cylinder.A The ennlloyinent of a plate cylin-` deifiiiltlie combination is important from the i point of view of obtaining reproductions Whiclifare all faithful to the original and alike in all respects.` li' the off-set cylinder is employed for transferring its impressions to a flat` printing plate, defects or infidelities may develop due to the pressure contact of the off-set roller upon a plane surface, and

further defects and `infidelitiesmay develop When such flat plate isbent and possiblyldis-` torted in order tomount it upona` printing cylinder. By the employment of a plate cylinder, simple mechanism `can be Aused foreffecting a co-operativevvorking of the parts, the transfer operation is accurately and smoothly performed, and the printing plate receiving the impressions is already in the cylindrical form in which it is ultimately to be used in the printing machine. The blanket cylinder may be rotatively adjustable in relation to its gear in order to enable a fresh segment of its surface to be brought into contact with the original.

Finally, as considerable pressure may be required, in some cases, between the plate Figure 3 is a view showing part of Figure 1 in a different working position.

Figure l is a diagrannnatic side elevation illustrating a trip mechanism for the plate cylinder.

Figure 5 shows in side elevation the platen carrier and means for raising and lowering the platen and Figure 6 is a sectional part plan of Figure 5. the upper wedge plate being removed.

Referring to the drawings. a is the framing of the machine having suitable guideways for supporting a sliding saddle or bedv b. thelatter being fitted with side racks c. A cylindrical body (Z, journalled at c in suitable parts of the framing, is fitted with an off-set cylinder f and revolubly supports toothed gears g for meshing with the racks c. The body rl is also fitted with a toothed gear 7L for meshing with a similar gear y' carried by a cylindrical body 7c. The last named is journalled at Z in revolubly adjustable eccentric bushes or sleeves m in 'the framing, the said eccentric bushes being formed with arms n which are pivotally connected with rods 0. Arms or the like on the shaft of a double pedal 79 are adapted for lifting or lowering' the rods o to effect adjustment of the bushes m for the purpose hereinafter described. The cylindrical body 7c is fitted with a plate cylinder q. The off-set cylinder f has a rubber or other off-set blanket r wrapped around it and is fitted with blanket stretching means di agrammatically indicated at s.

The plate cylinder() has a printing plate 1f, wrapped around it and tted with plate stretching means 'u and u of any suitable construction. Toothed pinions v mesh with the toothed gears g, the shaft c (shown by f' broken lines in Figure 1) of these pinions U being fitted with a driving pulley or hand wheel fw shown by chain lines in Figure 2.

Upon the sliding bed is a frame 7 by which is carried a vertically movable platform 6, having wedge shaped under surfaces adapted to be engaged by a wedge plate (3 also carried in the frame 7 and adjustable forwards and rearwards therein. This wedge plate Ga when moved forwardly allows the platform 6 to descend so as to lower a platen 3 carried by the said platform and when moved rearwardly raises the said platform and platen. Movement of the wedge plate 6a is effected by aV rock shaft 12 having an eccentric 13 on one or both of its ends which ends pass through horizontal guide slots 15 in the side members of the frame 7, each said eccentric 13 being revoluble between lugs 1G forming a vertical guide on the frame 7.

The rock shaft 12 which, by the eccentrics. is moved in the slots 15 in a direction at right angles to its axis engages between vertical lugs 17 on the wedge plate 61. -A lever 18 adapted to be operated by hand orby a suitable tappet on the machine frame, is suitably connected to the eccentric 13 whereby the eccentric is turned so as to move the rock shaft in its guides 15 and so through its engagement with the lugs 17 on the wedge plate 6a cause the latter to be moved either forwardly or rearwardly according to the direction of rotation of the eccentric. On the platform 6, a plate 1 having depending flanges is supported. A number of clips 2 are carried by the plate 1, which engage the platenY 3. An original design 5, for reproduction attached to the platen 3. The original design in the example shown is formed at one end of a narrow strip 5"L secured to the platen as by means of the clips 4. In its rearwardly adjusted position as shown in Figure 1l the wedge plate 6a has elevated the platform 6, plate 1 and platen 3 to a position in which the original 5, will make pressure contact with the blanket r of the Vofi` set cylinder f when the bed b is moved beneath the said cylinder. In its forwardly adjusted position as seen in Figure 3 and in dotted lines in Figure 5 the wedge plate (5a has permitted the platform 6 and the parts carried thereby to descend a little so that the original 5 on the platen 3 will not make contact with the off-set cylinder when 'the bed 7) performs return stroke as it is about to do in Figure 3. A fine adjustment of the platen 3 relatively tothe racks c and therefore the relation of the platen to the olf-set cylinder may be effected by the screw 7a on a longitudinal spindle 8 which revolubly engages the end cross members of the frame I), see Figure 1, and which screw works in a nut 9 in the rear end wall of the frame 7 The screw 7 a can be turned by a hand wheel 1() having a suitable scale on its periphery so that the amount of adjustment can be deitil) 6ZL isadjustedby the hand lever 18 before ythe platen 3 comes beneath-the off-set cylinder f so that it makes no contacttherewith; v The wheelor: pulleyw isthen turnedfor revolving the cylinders and g, and the blanket r transfers itsimpressions to the plate t which is then ready for use, or ready for development for use in a printingimachine.

Itwill be noted that the platen 3 is formed with sharply bevelled ends ltand it is important that the edge of .the originalv design 5 should coincide withthe angle between the horizontal top face and the end'bevel face of the platen 3.' By comparing Figures lfand 3 it willfbe seen that when a-transfer has been made upon an area of theV blanket r no further contacttakes place between such area and the platen 3. As soon as the cylinder fhas rolled over the original 5 `it'ceases to'make contact therewith owingto thebevel, and the platen- 3 is thereupon lowered for' the retu-rn move,- ments. The revoluble adj ustmentof the ofi'- set cylinder f to the new position has the result that'at the end of-the nextforward movement of the bed b that portion of the blanket upon'which a transfer has been made fails to reach the position in which contact can be made withtheforiginal 5, as` will be clear from the dotted position Figure 3, Thus, the impressions or transfers on the blanket r are never brought-into possibly harmful contact with the platen- 3 and remain-intact `untilthe moment arrives for their transfer to theV plate t. Y

If desired, impressions when produced on the plate maybe coveredwith lithographie gum solution in order to protect them against the blanket during contact periods occurring when further impressions are beingtaken.

Instead of rotatively adjusting the cylinder f g as above described, a similar result may be obtained by longitudinal adjustment of thebed b in lrelation to its rack c, or in relation to the cylinder f.

In order to take full advantage of the possibility of economizing space and of getting as many impressions as possible on a printing plate t, the width ofthe bed Z) is made greater than the length of the cylinders f and g so that the sides of the bed b are bcyond the respective cylinder ends as seen'in Figure 2. Thus, when the original copy is narrower in width than the plate 1, as is the case with the copy 5 in the eXampleillustrated, the saidv copy may be arranged cen-v trally on such plate l, and the latter be laterally adjusted to one side so that one of its unoccupied side or marginal portions is beyond the ends of theV cylinders at that side. Thus, the first row of impressions may be made upon the c-ylinder close to the edge thereof, as shown in Figure 2, so that no space is wasted and so that there may even be room foran additional circumferential .row which larmes placed in a true parallel position in relation tothe edge of the transferring blanket and/ or at a true right angle, and that any given position in relation to the cylinder maybe definitely andexactlyre-occupied subsequently.

It is to be understood that the press may be 5 used as a transfer press for originals either ofplanographic, relief, or intaglio character, andthat the plate cylinder may carry ma` terial-other than metal for receiving the oilset impression, such as textiles, ivorine, or celluloid.- j

Y 1'. Offseti printing machine for carrying out a method of the kind described, comprising. a blocker platen adapted for supporting I.;

theqoriginal, a reciprocatory bed, a transverse adjjiistmentoperative for shifting the platen laterally of saidbed, an off-set cylinder, gearingbetwee'n said cylinder and the reciprocatory bed, an adjustment operative for' turn- .f

ing said cylinderl through predetermined angles Ain relation to -said gearing, and a plate cylinder geared `with the off-setcylinder substantially as described.

2. Off-set printing ;machine for carrying outa method of the kind described, comprisinga blockor platen adapted 'for supporting theoriginal, a mechanism operative on said platenv for elevating or lowering the latter into andout of pressure contact relation with the off-set cylinder, a reciprocatory bed, a transverse adjustment operative for shifting the platen laterally. of said bed, van offset cylinder, gearing between said cylinder and said bed, an adjustment operative for turning said cylinder through pre-determined angles in relation to said gearing, and a plate cylinder geared with the off-set cylinder substantially as set forth.

3. Oli-set printing machine for carrying` out a method of the kind described, compris` ing a platen, adjustable into and out of pressure contact relation with an off-set cylinder, a reciprocatory bed supporting said platen and geared with the off-set cylinder, a clutch mechanism adjustable for altering the angular relation between the off-set cylinder and its gear, a plate cylinder constantly geared with the olf-set cylinder, and a trip mechanism operative for putting said plate cylinder loi and adapted for the mounting of the original j withr an edge of such original coinciding v with the commencement of the bevel, an adjustment for altering the elevation of said platen, a reciprocatory bed supporting said platen and geared with the oH-set cylinder, a mechanism adjustable for altering the angular relation between the olf-set cylinder and its gear and a plate cylinder geared with the off-set cylinder substantially as set forth.

5. Oli-set printing mac-hine `for carrying out a method of the lrinddescribed, comp-rising a platen, a reciproca-tory bed supporting same, an adjustment operative between said i bed and said platen'for altering the elevation of the latter, an olf-set cylinder, toothed gearing between said cylinder and said bed, and toothed clutch mechanism operative for turning said cylinderin relation to said gearing` substantially as set forth.

6. Off-setA printing machine. for carrying out a method of the kind described, comprising aplaten, a reciprocatory bed, precision adjustments operative vupon said platen for altering the longitudinal and lateral positions, an adjustment operativebetweenV said bed and said platen, for altering the elevation of saidplaten, an oil-set cylinder, toothed gearing between said bed and said cylinder,

and adjustable clutch mechanism operative for turning said cylinder in relation to said gearing substantially as set forth.

FRANCIS J. CONNOLLY.

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