US3645202A

US3645202A - Lithographic inking dampening system

Info

Publication number: US3645202A
Application number: US25507A
Authority: US
Inventors: Francis K Lake
Original assignee: Multigraphics Inc
Current assignee: AB Dick Co
Priority date: 1970-04-03
Filing date: 1970-04-03
Publication date: 1972-02-29
Anticipated expiration: 1989-02-28
Also published as: FR2089093A5; GB1315299A; CA928570A; BE765158A; DE2113722A1

Abstract

Ink and moisture rollers transport directly from their supply source to a form roller and metering means therefor also the arrangement of the rollers to each other and to the master cylinder.

Description

o 1 w r it tes aterit n 1 3,645,20 Lake Feb. 29, 1972 [S4] LITHOGRAPHIC INKING DAMPENING 3,352,317 11/1967 Dahlgren .l01/148 X SYSTEM 2,240,762 5/1941 Dietrich ..10l/350 430,269 1890 Clause et al... ....101/350 X [72] inventor: Francis K. Lake, Euclid, Ohio 2,733,654 2/1956 Rogers i ..101/ 148 2,689,522 9/1954 Curtis ...l0l/l48 X {731 Assgnee' Addmmgmp'l'mmgmph 2,534,320 12/1950 Taylor ..101/169 x Cleveland, Ohio V [22] Filed: Apr. 3, 1970 Primary Examiner-Clyde l. Coughenour [21] Appl 25,507 Att0rneyRussell L. Root and Ray S. Pyle [52] U.S.Cl ..l01/148, 101/350 [57] ABSTRACT [51] Int. Cl ,B41| 25/14 Ink and moisture rollers transport directly from their supply 58 Field of Search ..101/147, 148,350 source to a form roller and metering means therefor also the arrangement of the rollers to each other and to the master References Cited y n r- UNITED STATES PATENTS 4 Claims, 2 Drawing Figures 3,343,484 9/1967 Dahlgren ..101/350 X LITI-IOGRAPHIC INKING DAMPENING SYSTEM BACKGROUND OF THE INVENTION Historically the rotary offset printing press has used thick paste ink which is metered out of an ink fountain by an oscillating ductor roll to a series of many rollers, some of which oscillate along their longitudinal axes. These rollers divide and smooth out the ink until, ostensibly, the final roller which delivers the ink to the surface of a master printing plate on the master cylinder presents an extremely fine and evenly divided layer of ink. Presses for high-quality halftone printing have a greater number of such rollers whereas the more utilitarian presses used for line copy such as typing and artist drawing can use far fewer rollers efficiently.

Nevertheless, even greater ink distribution is sought in some instances, and at least one patent has issued in the United States which ostensibly breaks down the ink further and gives a greater reservoir of ink available for sudden demand. That patent is US. Pat. No. 3,150,589 issued Sept. 29, 1964. Whereas the practicality of this approach is possibly opened to question, the fact does remain that even distribution of ink supplied to the master on the master cylinder, presents a problem of sufficient supply in one location without over supply to another. The availability of large quantities of ink in one area as opposed to much less ink in another area of the same master is typical of the problems.

ADVANTAGES AND OBJECTS One of the primary advantages of this invention is that the path from the bulk ink supply to the demand area on a master cylinder is exceedingly short. Hence, it is an object of this invention to provide a fully adequate ink supply to meet any demand situation.

A further advantage of this invention is that liquid ink is metered to the form roll by means of a shear blade which establishes a completely uniform coating on the ink roll and hence to the form. By employing liquid ink and a shear blade, the need for dividing and subdividing among many rollers is circumvented.

A further advantage of this invention is to provide a complete ink and lithographic moisture fountain supply which is readily removable from the machine for cleaning.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a substantially schematic side elevation with some parts in cross section, illustrating the principals of the invention;

FIG. 2 is an end elevation view FIG. 1, but illustrating essentially only the supply system without the operating structure behind.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The drawing illustrates a machine which has been reduced to practice and is proven to be fully operative. This structure is illustrated in diagrammatic form only, because the nature and general principles of lithography are old and well known. Reference character refers to a master cylinder portion in order that the relationship of the inking system may be related to the master cylinder to be supplied.

A form roll 12, an ink roll 14 and a moisture roll 16 all are in surface contact with one another and the form roll is positioned to contact the surface of the master cylinder whenever the entire system is moved forward to cause such contact. Otherwise, the assembly of the three rolls and its supporting structure may be physically removed such that the roll 12 does not make contact. The contacting or not as the case may be is for the same reason that any form roll in any lithographic inking system is caused to contact or not.

This illustrated embodiment of the invention is built upon two side plates 18, and the rolls 12, 14 and 16 are journaled on the side plates by conventional bearings and mounting devices.

The conventional inking system, by using a series of rolls, causes an original deposit of ink or moisture to be passed to the next roll, and thus subdivided. The first roll will keep half and provide half to the subsequent roll. This dividing and subdividing process is continued until the necessary distribution and metering of both ink and moisture is achieved.

In this invention the plurality of rolls are eliminated and only one moisture roll 16 supplies moisture to the form roll 12 and one ink roll 14 provides ink to the roller 12. This is possible because of the combination of features which have been conceived and built into this illustrated apparatus,

The moisture is metered from the moisture roll 16 by means of a rod 20 which has a face shear blade 21 of compliant elastomer. In the illustrated position as shown in FIG. 1, the blade is tangential to the roller 16 and hence has a minimum wiping or shearing effect. Hence, a maximum film of moisture will be able to wedge between the face of the blade 21 and the surface of the roll 16. The amount of moisture is diminished by causing the rod to rotate about its axis and thus place a smaller surface area of the shear blade 21 against the surface of the roll 16. Hence, any pressure applied to the rod 20 will be applied through the blade in a smaller total area and therefore will cause a greater proportion of moisture to be stripped away from the surface of the roll 16.

The rod 20 is mounted between a pair of links 22, each being positioned laterally near the opposed walls 18. The rod 20 is affixed to the one end oflink 22 and hence is not free to float with respect to the link. Consequently, turning the link will cause the face of the blade 21 to turn.

In order to apply pressure to the rod 20, one end of link 22 is pivotally mounted to a pressure applicator link 24. The at titude of link 22 is controlled by attaching a link 26 to its opposite end. A pivot 28 for the link 24 permits application of pressure. To apply such pressure, an adjacent screw 30 on the top end of link 24 operates against a swingable link 31. Link 31 is pivoted at 32 and is pulled toward the link 24 by means of a spring 33. Adjustment of the longitudinal extend of the screw 30 will determine the amount of pressure applied to the rod 20, and the longitudinal position of link 26 will determine the rotational attitude of the rod 20 and hence the amount of area of the blade 21 subjected to the available pressure. By this means there is a combination of pressure, attitude and area to induce a precise flow of moisture past the contact area of the blade 21 to the roll 12.

The link 26 is adjustable by the operator through an apparatus which includes a guide yoke 36 extending laterally across the structure between the plate 18 and adapted thereby to guide a rod 38 in a forward and rearward movement. A rod 40 is connected between the side plates and serves as a pivotal support for the yoke. Also, the rod 40 is drilled to accept a stem of a threaded rod 42, which threaded rod is threadably engaged substantially at the center of the rod 38 and therefore is adapted to drive the rod 38 forward or rearwardly in the bit of the yoke 36 and hence drive the link 26 in producing the desired attitude of blade 21.

The ink roll 14 is contacted by a shear blade 34 to remove ink from the surface of the roll to the degree desired. The greater the contact pressure between the roll 14 and the blade 34, the smaller amount of ink will be permitted to pass. Then, according to the concepts of this invention, the roll 14 is caused to run with its lower perimeter area immersed in lithographic ink made liquid by a high percentage of extremely volatile solvent. Hence, any ink which is carried past the shear blade 34 and immediately deposited on the form roll 12 will be rapidly subjected to an increased viscosity and will permit deposit of a suitably viscuous form of ink onto the master on the master cylinder 10 for proper inking and printing function.

The ink and moisture solution are supplied to the rollers 14 and 16 in this particular embodiment by means of a pan 45 having a dividing floor 47 to mechanically separate the ink from the moisture area. The ink in this particular embodiment is in the lower compartment in order to flow forward and reach the ink roll 14, whereas the moisture is confined in the upper compartment where the roll 16 is partially immersed therein.

An ink bottle for supply of liquid ink is indicated by reference character 49 and is held by a bracket 50. The bottle 49 has a long neck portion which reaches down and extends through an opening in the floor 47 and thereby provides a constant supply of the fluid ink to that area. The level is maintained by the well known physical principles of pressure differential.

A moisture solution bottle 51 is also held by a bracket 52, and that bottle 51 is elevated in order that the moisture solution will be applied only into the upper area above the floor 47.

The pan is supported by rollers 54 shown in FIG. 1 at the remote end of the pan. Other rollers 53 are mounted on the ends of a rod 55 shown at the forward portion of the pan. The rod 55 extends across the bottom between the rollers 53 and is supported by readily removable bearing members for disengagement of the rod 55 from the sideplates 18.

A bracket 56 secured to the bottom of the pan 45 accepts a threaded rod 57. The rod 57 is secured rotatably to the rod 55 and hence enables the operator to adjust the longitudinal pan position. The shear blade 34 for the roll 14 is mounted on the end of the pan and therefore the operator adjusts the pan position in order to adjust the shear blade pressure against the roller 14 for metering the amount of ink desired.

The pan is held tight against rollers 54 by rollers 58 which ride a top edge of the pan. The pan can move laterally a limited distance, supported by the top and bottom roller sets 54 and 58, but because of the end wall configuration of the pan, it cannot be fully removed by rectilinear movement.

The front, or remote end of the pan has a closed track configuration in which the front roller 58 resides. By retracting the pan to deflect the blade 34 against the pan wall, the pan and the roller 58 will separate. The lower edge of the pan then will clear the remote roller 54 and allow the pan to drop at the front end. Thus the pan may be pulled free of the restraining rollers and removed from the machine for cleaning.

What is claimed is:

l. A liquid ink lithographic printing system, comprising:

a plate cylinder and means for printing from a plate on said cylinder;

a form roll in surface rolling contact with said plate cylinder at a radial position not higher than the horizontal diameter line thereof;

an ink supply roll of regular surface configuration free of ink-retaining recesses in rolling contact with said form roll at a radial position not higher than the horizontal diameter line thereof;

a fountain pan, means for providing and maintaining oleous liquid lithographic ink to a preselected level in said pan; means for positioning said pan to immerse a portion of said ink supply roll below said level;

means for shearing ink in excess of a predetermined layer thickness from said ink supply roll as it emerges from said fountain pan level to thereby establish a desired ink supply quantity available to supply said form roll;

a moisture supply roll in rolling contact with said form roll below the center of the form roll between the ink supply roll and form roll;

a moisture solution pan, means for providing and maintaining a lithographic moisture solution to a preselected level in said moisture solution pan;

means for positioning said moisture solution pan to immerse a portion of said moisture supply roll below said level;

means for shearing water from said roll as it emerges from said pan level to thereby establish a desired water supply quantity to said form roll; and

means for driving said ink and moisture supply rollers and form roll in such direction that the form roll surface comes first against said ink supply roll and thereafter against said moisture supply roll. 2. lithographic printing system as defined in claim 1,

wherein the moisture solution pan is nested within said ink fountain pan and each is kept to the predetermined level by gravity supply bottles.

3. A lithographic printing system as defined in claim 1, wherein film thickness of the fluids on the ink and moisture rollers reaching the form roll is established by blade surface, and by means to angle the blade surfaces under pressure against the rolls.

4. A liquid ink lithographic printing system as defined in claim 1, wherein said moisture solution pan is positioned in nest relationship with said ink fountain pan and dimensioned to close off said fountain pan, one side wall of said moisture solution pan ending closely adjacent a first side of said supply roll and said fountain pan having a sidewall closely adjacent the ink supply roll on a second side thereof.

Claims

1. A liquid ink lithographic printing system, comprising: a plate cylinder and means for printing from a plate on said cylinder; a form roll in surface rolling contact with said plate cylinder at a radial position not higher than the horizontal diameter line thereof; an ink supply roll of regular surface configuration free of inkretaining recesses in rolling contact with said form roll at a radial position not higher than the horizontal diameter line thereof; a fountain pan, means for providing and maintaining oleous liquid lithographic ink to a preselected level in said pan; means for positioning said pan to immerse a portion of said ink supply roll below said level; means for shearing ink in excess of a predetermined layer thickness from said ink supply roll as it emerges from said fountain pan level to thereby establish a desired ink supply quantity available to supPly said form roll; a moisture supply roll in rolling contact with said form roll below the center of the form roll between the ink supply roll and form roll; a moisture solution pan, means for providing and maintaining a lithographic moisture solution to a preselected level in said moisture solution pan; means for positioning said moisture solution pan to immerse a portion of said moisture supply roll below said level; means for shearing water from said roll as it emerges from said pan level to thereby establish a desired water supply quantity to said form roll; and means for driving said ink and moisture supply rollers and form roll in such direction that the form roll surface comes first against said ink supply roll and thereafter against said moisture supply roll.

2. A lithographic printing system as defined in claim 1, wherein the moisture solution pan is nested within said ink fountain pan and each is kept to the predetermined level by gravity supply bottles.