US2588470A

US2588470A - Inking mechanism for rotary lithographic presses

Info

Publication number: US2588470A
Application number: US728863A
Authority: US
Inventors: Bassist Ellis
Original assignee: AB Dick Co
Current assignee: AB Dick Co
Priority date: 1947-02-15
Filing date: 1947-02-15
Publication date: 1952-03-11
Anticipated expiration: 1969-03-11

Description

E. BASSIST March 11, 1952 INKING MECHANISM FOR ROTARY LITHOGRAPHIC PRESSES Filed Feb. 15, 1947 2 SHEETS-SHEET 1 A W. .W

March 11, 1952 E. BASSIST 2,588,470

INKING MECHANISM FOR ROTARY LITHOGRAPHIC PRESSES Filed Feb. 15, 1947 2 Sl-iEE'IfSSl-IEET 2 Patented Mar. 11, 1952 INKING MECHANISM FOR ROTARY LITHOGRAPHIC PRES SES Ellis liassist, Brookline, Mass., assignor,'by mesne assignments, to A. B. Dick Company, Niles, 111., a corporation of Illinois Application February 15, 1947, Serial No. 728,863

9 Claims. 1

The invention is primarily applicable to a machine adapted for printing from a lithographic plate by utilization of the offset principle, and the invention relates more particularly to the inking mechanism and immediately associated parts of such a machine. An inking mechanism embodying the invention is particularly adapted for use as a part of a machine of the character set forth which is simple and compact and which does 'not require the services of a highly skilled operator, being thus adapted for use in business ofiices and the like.

While not necessarily so limited, a machine with an inking mechanism and associated parts embodying the invention is particularly useful with a lithographic plate comprising a sheet of paper properly prepared to be receptive to an image formed by the application thereto of ink or other material of a greasy character. This image may be applied directly to the plate, for instance, by printing, or by typewriting, or by a crayon. The image may also be applied to the plate by treating the paper constituting the plate so that it is light sensitive and creating a photographic image thereon by photographic methods, and then applying a greasy material to the plate which adheres to the photographic image thereon, but which can be wiped off from the other parts of the plate.

During the printing process the lithographic sheet or plate is maintained in a moist condition and greasy ink is applied thereto which'adheres to the greasy portions constituting the image to be printed but is repelled by the other portions of the plate which are moistened. Then the ink is transferred from the lithographic plate to an offset printing blanket which in turn applies the ink to the paper or other material to be printed. It will be seen that so long as the plate is kept properly moistened the greasy ink adheres to the greasy image but not to the other portions of the plate, and it is therefore important'that the moistening be properly controlled, so that on the one hand it will not be excessive and so that on the other hand it will not be so deficient as to permit the ink to adhere to portions of the plate other than the image thereon. It is furthermore important that the ink be applied evenly and at the proper rate, as a deficiency in ink would result in poor printing and as an excess of ink would tend to cause it to adhere to portions of the plate other than the image, notwithstanding the moistening thereof.

.One object of the invention is to provide in combination with other parts of a printing machine, a suitable inking mechanism for applying ink to the plate uniformly and at a proper rate so as to insure good printing and to avoid any excess which might tend to accumulate on the plate notwithstanding the moistening thereof.

Notwithstanding the provision of a suitable moistening mechanism and notwithstanding care in the maintenance and adjustment thereof, it may sometimes happen that too much moisture is supplied to the plate. When this occurs the excess moisture forms an emulsion with the ink on the final ink applying roller, and this results in faint or grey printing. A further object of the invention is to provide means constituting a part of the inking mechanism and serving to eliminate any emulsion that may tend to form, thus assuring good printing at all times. Other objects of the invention will be apparent from the following specification and claims and from the attached drawings.

0n the drawings,

Fig. 1 is a perspective view showing a portion of a printing machine incorporating the invention.

Fig. 2 is a vertical longitudinal sectional view taken through the central portion of the machine.

Fig. 3 is a fragmentary sectional view of one of the moistening rollers, this view showing the roller at an intermediate step during the assembly thereof.

Fig. 4 is a view similar to Fig. 3, but showing the completed roller.

Fig. 5 is an exploded view of the parts of one of the moistening rollers prior to assembly.

Fig. 6 is a fragmentary detailed perspective view showing the left end of the moistening rollers and "the mechanism for holding and supporting them, this mechanism being in a different position from that shown in Fig. 1.

Fig. '7 is an enlarged fragmentary horizontal view, omitting the moistening device and taken partly in section along the line Tl of Fig. 2.

Fig. 8 is an exploded view of the parts associated with one of the inking rollers shown in Fig. "I.

Fig. 9 is an enlarged diagrammatic transverse sectional view through one of the auxiliary printing rollers.

Referring to the drawings, the main frame of the machine comprises two side plates H and i2 which are suitably connected by various means, including tie rods l3, l3. Extending transversely between the side plates is a shaft Hi carrying a cylinder l5 which'ean be rotated in the clockwise direction by means of a gear is on the shat-t I l,

which meshes with a suitable driving gear, not shown. The cylinder l has a transverse recess at I! in which are devices [8 for engaging suitable retaining clamps on the ends of a lithographic paper plate which is wrapped around the cylinder [5. These devices I8 permit the plate to be readily attached or detached and hold it firmly during the printing operation.

Also extending transversely between the plates II and I2 is a shaft 19 carrying a cylinder lS on which is a rubber offset printing blanket 2G. The cylinder I9 is so positionedth'at the'blanket 20 engages the plate on the cylinder IS, the two cylinders being rotated in unison but in opposite directions. Underneath the cylinder l9 is a pressure roller 2 I, and by means of a suitable feed mechanism, not shown, sheets of paper to be printed are introduced successively between thecylinder [9 and the roller 2 I, the sheets of paper after passing between the said cylinder and rollerbeing deposited in the paper receptacle 22 which is adjustable to accommodate sheets of various sizes.

As already stated, it is necessary in order to attain proper printing that the plate on the cylinder I5 be continuously moistened to an accurately predetermined extent. To this end a suitable moistening mechanism is provided which will now be described in detail. It will be understood, however, that the moistening mechanism does not of itself constitute any part of the present invention.

The moistening mechanism, as shown, comprises two

moistening rollers

23 and 24 parallel with the plate cylinder l5 and extending the entire length thereof. These rollers are formed, at least in part, of a porous sponge-like material such as cellulose sponge and they are adapted to retain a substantial amount of water. The rollers are rotated as the result of their engagement with the plate on the cylinder 15, and they serve by reason of their moist condition to maintain the plate in a moist condition.

The moisture in the

rollers

23 and 24 is replenished and maintained by means of a moistening pad 25 which isadapted to engage both of the rollers throughout their entire lengths. The upper portion of the pad 25 is enclosed in a housing 26 which serves to support the pad. Positioned above and carried by the housing 26 is a reservoir 21 for water, preferably slightly acidulated, to be supplied to the pad and from the pad to the moistening rollers and finally to the plate. The reservoir 21 is connected with the housing 26 by means of a plurality of

ducts

28, 28. Each duct has a screw 29 extending into it and controlled by a knob 30, this screw serving as a valve to regulate the flow of water through the duct. When the screw is at its inward limit of movement, the duct is entirely closed and by backing the screw outward the rate of flow through the duct can be regulated as required. Each duct has a window at 3| which enables the operator to observe the rate of flow through each duct. The reservoir 2'! has a filling opening normally closed by a threaded plug 32 and preferably has a window 33 through which the operator can observe the level of water in the reservoir.

The housing 26 is carried by a U-shaped yoke which is pivoted at 35, 35 to upstanding brackets on the side plates II and I2. The yoke 34 with the housing 26 and with all of the parts carried thereby can be swung upward about the axis of the

pivots

35, 35 to separate the pad 25 from the

rollers

23 and 24. The parts can be swung upward manually, as for instance when it is desired to obtain access to the rollers, and the parts can then be held in their elevated position by means of a pivoted strut 36, the lower end of which is adapted to engage a suitable stop 37 on the frame member I2.

Threaded into a suitable lug (not shown) on the y0ke34 is an adjusting screw 38, the lower end of which engages a plate on the top of the frame member II. This screw limits downward movement of the yoke 34 and of the housing 26 and thus serves to regulate the pressure between the moistening pad 25 and the

moistening rollers

23 and 24.

Under some conditions of operation it is preferable for the pad 25 to engage the

rollers

23 and 24 intermittently instead of continuously. To this end there is provided a cam 39 carried by a shaft 40 which is oscillated through a small are by a mechanism (not shown) in the interior of the machine. A roller 4| carried by the yoke 34 engages the cam 39, and this roller serves to raise and lower the yoke 34 and the housing 26 in accordance with the oscillation of the cam 39. Preferably, the roller 4| is adjustable with respect to the yoke 34, and as shown, it is connected with the yoke by means of a pivoted link 42 which is engaged by an adjustable screw 43 threaded in a bracket projecting laterally from the corresponding side arm of the yoke 34. By adjusting the screw 43 it is possible to vary the period of time during which the parts are elevated at each oscillation of the cam 39. Fig. 1 shows the cam 39 in its right hand position with the various parts elevated and with the pad 25 separated from the

rollers

23 and 24. When the cam moves toward the left the parts will be lowered to bring the pad 25 into engagement with the

rollers

23 and 24, the degree of pressure being determined, as already explained, by means of the screw 38. By adjusting the screw 43 downward, the extent of eleva: tion of the parts can be increased, thus decreasing the period of time during which the pad is in engagement with the rollers at each oscillation of the cam.

Each of the

rollers

23 and 24 is provided with an arbor 44 which projects at each end of the roller proper and is entered in notches at the tops of the plates II and I2. Each arbor has an annular groove near its end, and a latch plate 45 is provided with a key hole slot therein. The key hole slot is adapted to receive the end of the arbor 44, the upper narrower end of the slot receiving the grooved portion of the arbor. A spring pulls the latch plate downward and thus holds the arbor in place. When it is desired to remove a roller, the latch plates 45 at the ends thereof are lifted manually and moved endwise from engagement with the arbor, and then the roller is free to be manually removed.

It is sometimes desirable to move the rollers '23 and 24 out of engagement with the plate on the cylinder I5 without however entirely removing them from the machine. To this end there are provided two pivoted cam members 46. One of these said cams is shown in Fig. 1 but it will be understood that there is another similar one on the opposite side of the machine. These cam members are normally in an inoperative position as shown in Fig. 1. Associated with each of the cam members are small levers 41, 41, which are pivoted at 48 and which are positioned with their end portions underneath the

respective arbors

44, 44 as shown more clearly in Fig. 6. When the cam members 46 are moved from the position shown in Fig. 1 to the position shown in Fig. 6, upward projections 46 thereon engage the levers 41, 41 to swing them upward, the said levers engaging the

arbors

44, 64 and elevating the rollers.

As already stated, each of the rollers .23 and 5 24 is formed at least in part of a sponge-like porous material such as cellulose sponge. If the roller were formed entirely of the cellulose sponge it would be softer than is desirable and in order to make it more firm it preferably comprises a1- m ternating sections of the cellulose sponge and of a firmer and harder material such as felt. Referring particularly to Fig. 5, which shows the parts prior to assembly, the alternating smaller felt sections are shown at 48 48 and the alter- HS nating larger cellulose sponge sections are shown at 49, 46. There is a metallic retaining Washer 56 and a nut 5| adapted to engage a threaded portion of the arbor 44. After a preliminary compressing step, the several alternating sections so 48 48 and 49, 49 are placed on the arbor and are gradually compressed by means of the nut 5|. Fig. 3 shows the compression of the several sections at an intermediate stage. When the several sections have been fully compressed by the nut 5| the entire roller is thoroughly moistened and this moistening causes the sponge sections to expand so that they come into contact with each other and entirely enclose the smaller felt sections, as shown in Fig. 4. Then the enso tire roller is ground to provide a uniform cylindrical surface. It will thus be seen that the outer face of the roller consists entirely of the sponge material and that the felt sections serve merely to support the sponge material.

For applying ink to the plate on the cylinder l5 there is provided a roller 52 which will be designated as the ink applying roller. This roller is parallel with the plate cylinder I5 and extends the entire length thereof. The roller 52 is mountto ed on an arbor 53 and has a bushing which carries a gear 54 meshing with the aforesaid gear 16 on the shaft I4 carrying the plate roller. Thus the ink applying roller 52 is rotated with the plate cylinder but in the opposite direction. The roller 52 may be formed of a porous material such as felt or it may be formed of a nonporous roller composition of the type commonly used for printing rollers. It is shown as being formed of aroller composition and this has an important so advantage as-will presently appear. For supplying ink to the roller 52, there are provided other rollers which are preferably formed of porous material such as felt and which are adapted to carry or contain suitable quantities of ink so as 55 to constitute ink reservoirs. As shown, there are two rollers 55 and 56 parallel with the roller 52 and engaging it throughout its entire length. These rollers are respectively mounted on

arbors

51 and 58. There is also shown a third ink resco ervoir roller 59, preferably also formed of a porous material such as felt and adapted to also carry or contain a suitable quantity of ink. The roller 59 engages both of the rollers 55 and 56, and is mounted on an arbor 66. The last said roller 59 is preferably positively rotated by power and to this end its bushing or sleeve is provided with a gear 6| which meshes with a pinion 62 loosely mounted on a bushing on the roller 56 which is mounted on the arbor 58, this pinion 62' meshing with the beforementioned gear 54 which drives the roller 52.

As herein shown, all four of the rollers 52, 5'5,

56 and 59 are carried by a cradle which is movable relatively to the main frame of the .ma-

chine toward or from the plate cylinder l5, and it is so constructed and arranged that it may be entirely removable from the frame as a unit with the rollers. As shown, the cradle comprises

side plates

63 and 64 suitably connected by tie rods such as 65, 65. The several arbors '53, 57, 58 and 60 fit into suitable bearing apertures and notches in the

plates

63 and 64.

Each of the

side plates

63 and 64 of the ink roller cradle engages lower and

upper guide members

66 and 61 which are secured to the main side plates H and I2 and which permit it to slide inward and outward. Spring means are provided by biasing the cradle for inward movement toward the plate cylinder l5 and, as shown, each of the guide members 66 carries a latch 68 which is pivoted thereto for movement about an axis perpendicular to the direction of sliding movement. Each latch carries a spring-pressed plunger 6!; provided with a knob 10, and the inner ends of the spring-pressed plungers are adapted to enter small recesses in the corresponding side plate of the cradle when the latches are in the positions shown in Figs. 1 and 2. The spring-pressed plungers serve not only to bias the cradle for inward movement but also to hold the cradle in place. Byengaging the knobs I6, It and withdrawing the plungers in opposition to the springs, the latches can be disengaged from the

plates

63 and 64 and can be swung respectively toward the left and toward the right so as to leave the cradle entirely free. Thereupon the entire cradle with the rollers journaled therein can be withdrawn as a complete self-contained inking unit and entirely removed from the machine.

By maintaining a spare cradle with attached parts, the machine can be kept in operation notwithstanding any necessity for replacing a roller or making other repairs or adjustments. Furthermore, different cradles'with attached parts can be provided for different colors of ink. The color of the printing can be quickly changed by removing one cradle and substituting another.

Under some conditions in the operation of the machine, it is desirable to retract the ink roller cradle sufficiently to disengage the roller 52 from the plate cylinder l5 Without however disengaging the gears l6 and 54. This is particularly necessary prior to the commencement of actual printing, while the moistening device is being suitably adjusted and while the lithographic plate is being initially moistened. For effecting this retraction there is provided a transverse shaft H provided with a knob 12 on the exterior of the machine. Carried by the shaft are two cams I3 of which one is shown in Fig. 2. When the cams are in positions shown in Fig. 2, the ink roller cradle is permitted to be moved inward by the springs so that the roller 52 will engage a plate on the cylinder l5. However, by turning the knob 12 in the clockwise direction the cams l3 will engage the inner edges of the

plates

63 and 64 to force the cradle toward the right in opposition to the spring-pressed plungers, thus retracting the entire ink roller machanism.

The ink reservoir rollers 55 and 56 can be readily removed from the cradle without disturbing the other rollers. Referring particularly to the roller 55 it will be observed that its arbor 51 is entered in notches in the

respective plates

63 and 64 and that it is held at each end by a spring latch 14 having'a key hole slot therein which receives a grooved portion near the end of the shaft. By manually lifting the latches 14, the arbor 51 can he released, thus making it possible 1 for the roller 55 to be manually removed. The roller 56 is similarly held but is removable downward, and repetition of the description is unnecessary.

Means is preferably provided for longitudinally reciprocating the roller 59 as it is rotated. Surrounding the arbor 60 is a sleeve 15 which carries the roller and which also carries the beforementioned gear 6|. The arbor 60 is reduced in diameter at its left end to provide a shoulder 16, and a sleeve ll surrounds the reduced end portion of the shaft being held between the cradle side plate 63 and the shoulder 76. The extreme left end of the arbor 60 is threaded and is held in place by a thumb nut 18 which engages the cradle side plate 63. The sleeve 11 is provided with helical grooves 79 of opposite pitch which intersect each other and which are connected at their ends. The sleeve I carries a bushing 86, and the said bushing an and the sleeve 15 have registering openings 8! and 82 in which is fitted a follower member 83 having teeth which engage the helical grooves 19 in the sleeve 77. The member 83 is rotatable in the openings 8| and 82 so as to accommodate itself to the successively reversed pitches of the helical grooves 19. The member 83 is engaged by a spring ring 84 which surrounds the bushing 86. The spring ring holds the member 83 in place without interfering with its necessary oscillation to accommodate the reversed pitches in the helical grooves. Thus as the roller 59 is rotated, the follower member causes it to reciprocate longitudinally. The gear 6| also reciprocates but it is of sufficient width to permit it to remain in mesh with the pinion 62.

In the operation of the machine a suitably prepared plate with an image thereon, all is as previously described, is placed on the cylinder l5 and seemed by the holding devices at l8. While the plate is being put in place, the moistening pad and associated parts may be held elevated by the strut 36, and the

rollers

23 and 24 may be held away from the cylinder i5 by the cam members 46. During printing the cylinder I5 is rotated in the clockwise direction and the plate thereon is continuously moistened by the

rollers

23 and 24. The moisture content of the said rollers in maintained by moisture supplied from the pad 25 and the moisture content of the

rollers

23 and 24 can be varied by changing the pressure between the pad and the rollers by means of the adjusting screw 38, and it can further be varied by utilizing the cam 39 to periodically lift the pad out of engagement with the rollers for suitable time intervals. The moisture content of the rollers can be still further varied by adjusting the

screws

29, 29 to change the rates of flow through the

ducts

28, 28. It will be observed that the moisture can be varied so as to be different at different positions extending transversely of the plate. For instance, if only a narrow plate is being used it may be desirable to entirely out off the flow of moisture through one of the ducts 28.

During printing, ink is applied to the plate on the cylinder 15 by the ink applying roller 52 which receives ink from the

ink reservoir rollers

55, 56 and 59. These latter rollers are porous and are adapted to contain substantial quantities of ink, and the ink in therollers canbe replenished from time to time by adding it directly to the roller 59 and allowing it to permeate through all three of the reservoir rollers. The ink can be added manually or by means of a suitable ink supply device (not shown). The

reservoir rollers have suflicient capacity to enable the machine to operate for a considerable length of time without the necessity for replenishing the ink.

While a plate is being put in place on the cylinder l5 or during initial moistening of the plate or when it is desired to discontinue printing without stopping the entire machine, the entire inking device may be retracted toward the right by means of the knob 12 and the earns 13, this retraction disengaging the ink applying roller 52 without bringing the

gears

54 and 16 out of mesh.

With the moistening device and the inking device both in operation, ink is applied to the mage on the plate but not to the other portions of the plate and the ink so applied is picked up by the offset printing blanket 20 and transferred to the paper or other sheets to be printed which are fed between the offset cylinder l5 and the pressure roller 2i. The printed sheets are delivered to the receptacle 22.

The ink, having substantial viscosity, does not permeate the entire bodies of felt constituting the

rollers

55, 56 and 59, and in fact permeates only the outer portions thereof as indicated in Fig. 9. However, any water that may be mixed with the ink is much less viscous and will permeate the felt of the rollers to a much greater extent. The felt thus serves as a medium for separating any water from the ink. As already pointed out, too much water may sometimes accumulate on the lithographic plate and this is picked up by the ink applying roller 52. The result is that an emulsion of ink and water is formed on the roller, and this emulsion, if allowed to remain on the roller, would cause poor printing. However, the ink applying roller 52 is in contact with the felt rollers 55 and 56 and the capillary action of the felt withdraws water from the roller 52, thus avoiding the building up thereon of any substantial emulsion of ink and water. The water by reason of its low viscosity penetrates to the interiors of the rollers 55 and 56, as indicated in Fig. 9, and does not interfere with the function of the rollers 55 and 56 as ink reservoirs. In other words, the porous roller has a permeability to water which is greater than its permeability to ink and this effects the separation.

The formation of the ink applying roller 52 of nonporous material is highly advantageous for the reason that the roller so formed has but a limited affinity for ink and, when used with a porous roller or rollers, can carry only a surface layer of ink such as is necessary for printing. If there is any tendency for an excess quantity of ink to build up on the applying roller such excess is pulled back into the inking or

ink reservoir rollers

56 and 51 which have a greater affinity for the ink. Furthermore, the porous rollers have an even greater afiinity for water than for ink, and if there is any tendency for the formation of an ink and water emulsion on the ink applying roller the water is withdrawn from such emulsion by the porous ink reservoir rollers. By utilizing the nonporous roller for applying ink to the plate and by combiningsuch roller with the porous ink reservoir rollers, which have the functions of holding excess ink and of separating water from ink, there is definite assurance that ink, unmixed with water, will be applied to the plate at the proper rate.

' Having thus disclosed the invention and described in detail a specific embodiment thereof for purposes of illustration, I claim as new and desire to secure by Letters Patent:

1. In a lithographic printing machine having a rotating cylinder for mounting a lithographic printing plate on the peripheral surface thereof, an inking roller mounted for rotational movement in surface contact with the cylinder for mounting the printing plate for applying ink thereonto, a first ink reservoir roller mounted for rotational movement in surface contact with the ink applying roller but out of contact with the. cylinder for mounting the printing plate, a second ink reservoir roller mounted for rotational movement in surface contact with said first ink reservoir roller but out of contact with said ink applying roller and for reciprocation axially relative thereto during rotational movement, said ink reservoir rollers being formed of porous material having a permeability to water greater than that to ink for removing excess Water from the ink applying roller and absorbing same into the interior thereof while ink for transferring to the ink applying roller locates in the outer portions thereof.

2. In a lithographic printingmachine having a rotating cylinder for mounting a lithographic printing plate on the peripheral surface thereof, an ink applying roller of non-porous material mounted for rotational movement in surface contact with the cylinder for mounting said plate and for applying ink thereonto, a first group of ink reservoir rollers each mounted for rotational movement in surface contact with the ink applying roller but out of contact with the cylinder for mounting the printing plate, a second ink reservoir roller mounted for conjoint rotational and reciprocal axial movement in surface contact with said first ink reservoir roller, said ink resen voir rollers being formed of porous material having-a higher permeability to water than to ink.

3. In a lithographic printing machine having a rotating cylinder for mounting a lithographic printing plate on the peripheral surface thereof, an ink applying roller of non-porous material mounted for rotational movement in surface contact with the cylinder for mounting said plate and for applying ink thereonto, a first group of ink reservoir rollers each mounted for rotational movement in surface contact with the ink applying roller but out of contact with the cylinder for mounting the printing plate, a second ink reservoir roller mounted for conjoint rotational and reciprocal axial movement in surface contact with said first ink reservoir roller, said ink reservoir rollers being formed of porous material having a higher permeability to Water than to ink, and means for adjusting said rollers as a unit in the direction toward and away from the cylinder for mounting the printing plate to bring the ink applying roller into and out of surface contact with said cylinder when in positions of use and non-use respectively.

4. In a lithographic printing machine having a rotating cylinder for mounting a lithographic printing plate on the peripheral surface thereof, an ink applying roller of non-porous material mounted for rotational movement in surface contact with the cylinder for mounting said plate and for applying ink thereonto, a first group of ink reservoir rollers each mounted for rotational movement in surface contact with the ink applying roller but out of contact with the cylinder for mounting the printing plate, a second ink reservoir roller mounted for conjoint rotational and reciprocal axial movement in surface contact with said first ink reservoir roller, said ink reservoir rollers being formed of porous material having a higher permeability to water than to ink, means mounting said roller onto a carriage adjustable to bring the ink applying roller into and out of contact with the cylinder for mounting the printing plate, and spring means constantly urging said first means in the direction to position said ink applying roller in surface contact with the cylinder for mounting the printing plate.

5. In a lithographic printing machine having a rotating cylinder for mounting a lithographic printing plate on the peripheral surface thereof, an ink applying roller of non-porous material mounted for rotational movement in surface contact with the cylinder for mounting said plate and for applying ink thereonto, a first group of ink reservoir rollers each mounted for rotational movement in surface contact with the ink applying roller but out of contact with the cylinder for mounting the printing plate, a second ink reservoir roller mounted for conjoint rotational and reciprocal axial movement in surface contact with said first ink reservoir roller, said ink reservoir rollers being formed of porous material having a higher permeability to Water than to ink, and gear means interconnecting said cylinder for mounting the printing plate with said ink applying roller and second ink reservoir roller for effecting conjoint rotational movement.

6. In a lithographic printing machine having a rotating cylinder for mounting a lithographic printing plate on the peripheral surface thereof, an ink applying roller of non-porous material mounted for rotational movement in surface contact with the cylinder for mounting said plate and for applyin ink thereonto, a first group of ink reservoir rollers each mounted for rotational movement in surface contact with the ink applying roller but out of contact with the cylinder for mounting the printing plate, 'a second ink reservoir roller mounted for conjoint rotational and reciprocal axial movement in surface contact with said first ink reservoir roller, a carriage block mounting said rollers and adjustable to position said ink applying roller into and out of contact with the surface of the cylinder for mounting the printing plate, and gear means interconnecting the cylinder, the ink applying roller and the second ink reservoir roller to establish a driving relation therebetween.

7. In a lithographic printing machine having a rotating cylinder for mounting a lithographic printing plate on the peripheral surface thereof, an ink applying roller of nonporous material mounted for rotational movement in surface contact with the cylinder for mounting said plate and for applying ink thereonto, a first group of ink reservoir rollers each mounted for rotational movement in surface contact with the ink applyin roller but out of contact with the cylinder for mounting the printing plate, a second ink reservoir roller mounted for conjoint rotational and reciprocal axial movement in surface contact with said first ink reservoir roller, a cradle in which said rollers are journalled, said cradle being adjustable in the direction toward and away from the cylinder for mounting the printing plate to position said ink applying roller into contact with the surface of said cylinder when in position of use, gear means interconnecting the cylinder, the ink applying roller and the second ink reservoir roller to establish a driving relation therebetween, and manually operating means for shifting said cradle in the direction away from the cylinder for mounting the printing plate by an amount calculated to take the ink applying roller out of contact with the surface of the cylinder but not so much as to disengage the gear means interconnectin the ink applying roller with the cylinder.

8. In a lithographic printing machine having a rotating cylinder for mounting a lithographic printing plate on the peripheral surface thereof, an ink applying roller of non-porous material mounted for rotational movement in surface contact with the cylinder for mounting said plate and for applying ink thereonto, a first group of ink reservoir rollers each mounted for rotational movement in surface contact with the ink applying roller but out of contact with the cylinder for mounting the printing plate, a second ink reservoir roller mounted for conjoint rotational and reciprocal axial movement in surface contact with said first ink reservoir roller, said ink reservoir rollers being formed of porous material having a higher permeability to water than to ink, the ink reservoir rollers being adapted to carry a supply of ink for transfer to the ink applyin rollers while absorbing excess water into the interior thereof from the surface of the ink applying roller to prevent ink emulsification.

9. In a lithographic printing machine having a rotating cylinder for mounting a lithographic printing plate on the peripheral surface thereof, an ink applying roller of non-porous material mounted for. rotational movement in surface contact with the cylinder for mounting said plate and for applying ink thereonto, a first group of reservoir roller mounted for conjoint rotational and reciprocal axial movement in surface contact with said first ink reservoir roller, a cradle in which said rollers are journalled, said cradle 12 being adjustable in the direction toward and away from the cylinder for mounting the printing plate to position said ink applyin roller into contact with the surface of said cylinder when in position of use, gear means interconnecting the cylinder, ink applying roller and the second ink reservoir roller to establish a driving relation therebetween, manually operating means for shifting said craxile in the direction away from the cylinder for mounting the printing plate by an amount calculated to take the ink applying roller out of contact with the surface of the cylinder but not so much as to disengage the gear means interconnecting the ink applying roller with the cylinder, and spring pressed latching means for securing said first ink reservoir rollers in position of use and for urging said rollers when in position of use into surface contact with each of said applying and said ink reservoir rollers respectively.

ELLIS BASSIST.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 191,696 Maurice June 5, 1877 523,235 Pelstring July 17, 1894 1,558,108 Marquardt Oct. 20, 19 5 1,920,424 Mollet Aug. 1, 1933 1,962,156 Rowell June 12, 1934 2,033,950 Morse Mar. 17, 1936 2,035,127 Hinton Mar. 24, 1936 2,090,361 Steinmetz Aug. 17, 1937 2,326,777 Guth Aug. 17, 1943 2,335,954 Neal Dec. 7, 1943 FOREIGN PATENTS Number Country Date 538,319 France June 8, 1922