US3298305A - Inking mechanism held in an indenting relationship with the form roll - Google Patents

Description

A. W. ECHANI IONSHI NOON 3,298,305 s ELD IN AN INDENTING P TH THE FORM ROLL Original Filed April 28, 1961 Jan. 17, 1967 INKING M RELAT FIG.

FIG. 2.

R N m N N E w 0 m L A ATTORNEYS rolls.

United States Patent 3,298,305 INKING MECHANISM HELD IN AN INDENTING RELATIONSHIP WITH THE FORM ROLL Alonzo W. Noon, Los Altos, Calif., assignor to Harris- Intertype Corporation, Cleveland, Ohio, a corporation of Delaware Continuation of application Ser. No. 172,348, Feb. 9, 1962, which is a continuation of application Ser. No. 106,271, Apr. 28, 1961. This application Sept. 8, 1965, Ser. No. 490,763

6 Claims. (Cl. 101-366) The present invention relates to a printing press and more particularly to the inking mechanism therefor. This application is a continuation of my co pending application S.N. 172,348 filed February 9, 1962, and now abandoned, which was a continuation of application S.N. 106,271, filed April 28, 1961 and now abandoned.

In rotary printing presses, a layer of ink is applied to those areas of a printing plate which are image areas to the printed. Inwa lithographic printing press, the ink is applied across the plate but limited to image areas by virtue of the fact that the image areas are ink receptive and the other areas are ink repellent. In letterpress printing, the ink is limited to the image areas by reason of the fact that the other areas are recessed.

conventionally, inking mechanisms for printing presses have involved a train of ink distributing rollers for applying a coating of ink to an ink form roller running tion as ink distributing and smoothing out rolls also function as storage rolls and introduce a considerable time delay in any adjustment of the inking mechanism since the adjustment first starts at the ink fountain and must be transmitted down through theink distributing Accordingly, considerable wastage of paper and time will occur when an ink adjustment is required.

Ghosting is a common problem in inkers where the form roll for inking the plate or type on the plate cylin- 'der is not commensurate in size with the latter, and most commonly occurs when the plate has circumferentially spaced image areas to be solidly inked and intermediate lightly inked areas. In such a case, it is frequently found that the final result of a solidly inked area will include a ghost of another one of the solidly inked areas on the plate.

The ghosting results because the coating of ink on the form roll is not sufficiently restored by the inking mechanism so that the form roll has uniform coating over the surface thereof as the surface moves into contact with the printing plate. When this happens, the coating of ink on the surface of the form roll which has inked one of the solidly inked areas is not sufficiently restored so that when that area attempts to ink partof another solidly inked area, insuflicient ink is supplied to the plate and the distinctive outline or shape of the first solidly inked area will be visible in the second solidly inked area.

Another problem in inkers is that of starvation or non-uniform distribution of ink longitudinally along the plate cylinder. Since various circumferential zones orcolumns on the plate cylinder require different amounts of ink depending upon the presence or absence of heavily inked areas from the columns, different amounts of ink are required for different circumferential columns. While ink keys are conventionally required to adjust this, it is a highly skilled operation to effect proper adjustment and it is commonly done by trial and error methods althgugh certain techniques have recently been developed for presetting of the ink keys.

An important object of the present invention is to pro- 3,298,305- Patented Jan'. 17, 1967 "ice vide a new and improved printing press having an inker which overcomes the problems of ghosting and starvation to the extent that the printing is commercially acceptable and also one which has a fast and immediate response to ink adjustments.

Yet another object of this invention is the provision of an inking system that will produce a thin, uniform film of ink directly from the fountain with a simple and direct arrangementfor adjusting film thickness.

It is another object of the present invention to provide a rotary printing press in which the inking arrangement for applying an ink coating to the plate includes only one form roll to which ink is delivered for application to the plate and ink fountain means for directly applying a coating of ink to the roll without intermediate rolls, the ink being applied to the plate in such a manner that the ink film is continuously regenerated so that a uniform thickness of ink coating is maintained on the portion of the roll approaching the plate even though the image areas have circumferentially spaced solidly inked areas and distinct charges in image areas both circumferentially and axially of the cylinder.

A still further object of the present invention is to provide a new and improved printing press in which the plate on the rotating plate cylinder is inked by an inking mechanism having only one roll to which ink is delivered from a supply for application to the plate with the roll being a form roll which runs in contact with the plate to apply the ink thereto and in which a uniform coating is initially formed on the roll and continuously regenerated by the use of an ink fountain which supplies ink, preferably under pressure, to the side of a nonmoving member which is pressed against the rotating form roll.

I have found that the problems of ghosting and starvation can be over-come and .a fast response obtained to changes in the ink settings if the inking arrangement embodies an ink form roll and ink applying mechanism for forming directly on the form roll without an intermediate train of rolls a uniform coating of ink which is constantly regenerated so that the portion of the form roll which engages the plate always has an ink coating of predetermined thickness thereon and that this uniform coating may be applied and constantly regenerated with the use of a non-rotating member pressed against the form roll. Heretofore, it has not been appreciated that ghosting and starvation may be eliminated by use of a single roll inking arrangement in accordance with the invention to obtain an inke'r which would have extremely fast response to adjustments and changes in ink requirements.

Further objects and advantages of the present invention will be apparent from the following detailed description of the preferred embodiment made with reference to the accompanying drawings forming a part of the present specification for all matter disclosed therein and in which:

FIG. 1 is a plan view, partly diagrammatic, of a plate cylinder and inking mechanism embodying the present invention;

FIG. 2 is a sectional view taken approximately along lines 2-2 of FIGURE 1 with the plate cylinder and form roll shown in end elevation; and

FIG. 3 is an enlarged detail of a portion of FIGURE 2.

Referring to the drawings, only the plate cylinder for a printing press and the inking mechanism are illustrated therein, the plate cylinder being designated by the reference numeral 50. It will be understood that the plate cylinder cooperates with other cylinders of the printing press in a conventional manner to print ,an image. In the case of a lithographic printing press, the press will include dampening mechanism for applying a dampening solution to the plate cylinder 50 and the plate cylinder will cooperate with the blanket cylinder while in the case of letterpress printing the cylinder will cooperate with a tympan cylinder. The cylinders or structures with WhlCh .the plate cylinder may cooperate are well known to those skilled in the art and therefore are not illustrated in the drawings.

Referring to FIG. 1, the printing plate to be inked is mounted on the plate cylinder 50 and is inked by a single form roll 30 which is smaller in size than the plate cylinder and which runs in contact with the surface of the plate mounted on the plate cylinder 50. While the drawings do not illustrate means for mounting a printing plate on the cylinder, it may be mounted in any conventional manner well known to those skilled in the art, the conventional plate cylinder in a lithographic printing press having a gap in the periphery thereof in which clamps or other mechanisms are disposed to hold the plate on the cylinder. The form roll 30 is the only roll of an inking mechanism which applies ink to the plate, the mechanism including the inking head 16 and an apparatus for feeding or delivering ink to the inking head through a conduit 12 which connects the apparatus 10 with the inking head 16 and which is received in a conduit or passageway 14 in the inking head. The conduit 14 communicates with an interior plenum chamber 18 in the inking head which is a closed chamber except for an ink delivery slot 26. The ink delivery slot 26 is immediately adjacent the outer surface of the form roll 30, which is designated by the reference numeral 28.

The inking head 16 has top and bottom walls 22, 24 which provide the top and bottom walls for the plenum chamber 18 and the bottom wall 24 is inclined upwardly to converge toward the top wall 22 to define the delivery slot 26. As illustrated in the drawings, the bottom wall defines a smaller angle with respect to a tangent plane at the roll than does the top wall 22. The edges of the walls 22, 24 which define the slot 26 are adapted to be indented into the surface of the form roller 30. The surface of the form roll 30 is a resiliently compressive material, such as neoprene. Since the form roll 30 is the only roll of inker, it is preferably driven in a conventional manner, as by gears from the press drive, so that it does not slow down when the gap of the plate cylinder, in the case of a lithographic press and some letterpresses, or when areas where no print is present, in the case of a conventional letterpress, passes the form roll.

As illustrated in FIGS. 1 and 2, the inking head 16 has a depending flange 32 which is pivoted to a support block 34 mounted on a base member 36. The pivot axis for the inking head 16 extends parallel to the length of the axis of the form roll 30 and the inking head may be moved about its pivot to establish a pressure relationship between the inking head and the form roller 30 to indent the surface by the thumb screws 38, one thumb screw 38 being adjacent each of the opposite ends of the inking head 16. The thumb screws 38 are threaded into the support member 34 and project therefrom to engage the underside of the inking head 16 and when threaded outwardly from the support member cause the inking head 16 to move counterclockwise about its aXis as the inking head is viewed in FIG. 2 to indent the surface of the form roll 30.

In operation, the apparatus for feeding ink supplies ink under pressure to the plenum chamber 18 and the ink is forced from the plenum chamber 18 outwardly from the delivery slot which preferably, as in the illustrated embodiment, extends axially for the full length of the roll 30. The ink when leaving the delivery slot is formed into a film as it passes between the top wall 22 and the roll 30, the top wall 22 constituting a stationary, i.e., a non-rotating, member which extends along the roll 36 and functions in the manner of a doctor blade to form a film from the quantity of ink delivered to the roll. It has been found that the inking head is capable of continuously regenerating the film on the form roll 30 so that a uniform layer of ink is maintained between the inking head 16 and the plate cylinder 50 even though the plate cylinder 50 has circumferentially or axially spaced areas which are to be inked solidly separated by lightly inked solid areas.

The thickness of the ink film deposited on the roller 30 depends upon some interrelated factors. For example, the properties of the ink are important. However, for a given ink, film thickness can be controlled at least in part by the ink-supply pressure. The film thickness can also be controlled by the pressure between the ink head and the roll which can be changed by varying the force used to hold the head against the roll.

In operation, the pressure between the inking head and roll is adjustable by the adjustment of the screws 38 to control the thickness of the ink film on the form roll. The film is formed and controlled primarily by the hydrodynamic effect at the corner edge of the top wall 22 which defines the outer upper edge of the delivery slot 26 as the latter is viewed in FIGS. 2 and 3.

The indented part of the wall 22 immediately adjacent the ink supply may be described as a film forming portion 22a of a film forming member, i.e. wall 22, the film ,forming portion comprising an edge portion 22b that leads the film forming member to indent the yieldable material forming the surface of the form roll to form a significant indentation therein. Moreover, from the foregoing description, it can be seen that the edge portion, 22b is supported radially inwardly of an arcuate plane defined by the arcuate surface of the form roll by support means which comprises means for maintaining the edge portion 22b in an adjusted position radially inwardly of the arcuate plane and holding it against lifting by the ink film on the roll so as not to detrimentally affect the hydrodynamic effect and for adjusting the extent of the indentation. In the illustrated embodiment the screws 38 function to adjust and position the edge portion 22b and in the illustrated structure positively lock it against outward movement.

The end side of the wall 22 which is adjacent to the form roll 30 may be provided with a cut out or notch 40 which provides a recirculating chamber. The ink issuing from the delivery slot 26 may mix with the ink remaining on the form roll 30 in the recirculating chamber. The recirculating chamber is not necessary for the performance of the present invention and the end side of the top wall may lie entirely in the plane of the portion which defines the upper outer corner edge of the delivery slot 26.

In the illustrated embodiment, a plurality of apertures 42 or passageways are provided in the upper wall 22. These apertures lead through the cavity through the top surface of the wall and enable ink to be fed from the cavity and are controlled by the means of the gap member 44. This member may be slidably mounted and may be covered to pass the passageway 42 or to partially cover the openings. The member 44 is held in place by means of a plurality of screws 46 which thread into the upper wall 42.

Referring to FIG. 3, it will be noted that the end side of the top wall 22 which has the recess 40 therein includes an upper or corner portion as the latter is viewed in FIG. 3 which forms the upper side of the recess 40 and an upper corner of the top wall 22 and that this portion also indents the surface of the form roll 30. If the recess 40 is omitted, this portion may be omitted so that the top wall 22 will indent the form roll 30 only along the lower left hand corner edge of the top wall 22, i.e., the edge which forms the outer upper edge of the delivery slot 26.

From the foregoing, it can now be seen that the present invention provides a new and improved printing press and method in which ink is delivered in quantity to an ink form roll by an inking head or fountain disposed irn mediately adjacent to the form roll and when the ink is applied to the form roll it is then converted into a film by the action of a stationary, i.e., non-rotating member which is indented into the member to provide a hydrodynamic effect which forms the quantity of ink into a film. The inking mechanism does not include a conventional train of rolls for applying ink to the ink for-m roll and responds rapidly to adjustments and is also capable of continuously regenerating a uniform film of ink on the ink form roll so as to eliminate problems of ghosting and starvation.

Having described my invention, I claim:

1. In a printing press having a plate cylinder, inking mechanism for inking a printing plate on said plate cylinder comprising, a plate form roll having a resiliently yieldable peripheral portion providing an arcuate pheripheral surface defining an arcuate plane, said form roll being operable to run in engagement with a plate on said plate cylinder, means supporting said form roll to run in engagement with said plate, ink head means comprising a non-rotating film forming member having a film forming portion extending axially along said form roll, said roll approaching said film forming portion from one side thereof as said roll rotates, means for supplying ink in quantity to said roll at said one side of said film forming portion, said film forming portion having an edge portion which leads said film forming portion to engage and indent said resiliently yieldable portion of said form roll, and support means for supporting said film forming portion in a position with said edge portion disposed radially inwardly of said arcuate plane to form a significant indentation in said roll on the side of the location of the ink supply away from the approach side of said roll, said support means including means for adjusting and maintaining the position of said edge portion radially inwardly of said arcuate plane to adjust the depth of said indentation and said means for adjusting and maintaining the position of said edge portion holding said edge portion again-st lifting by the film on said roll, and said fil-m forming portion cooperating with the surface portion of said roll to define said indentation and form a thin uniform ink film on said roll as said roll rotates relative to said film forming member.

2. In a printing press as defined in claim 1 wherein said adjustable means positively holds said edge portion in its adjusted position during the formation of said ink film.

3. In a printing press as defined in claim 2 wherein said means for supplying ink supplies ink under pressure to said roll and which pressure is adjustable.

4. In a printing press as defined in claim 3 wherein said form roll is of a size difierent from that of said plate cylinder.

5. In a printing press as defined in claim 1 wherein said ink head means comprises another non-rotating member spaced from said film forming member in advance of the latter, said members defining a slot therebetween through which the ink is delivered to said \form roll, said another member approaching said form roll at a smaller angle with respect to a tangent plane at said roll than said film forming member.

6. In a printing press as defined in claim 5 wherein said edge portion of said film forming member comprises an edge surface defined by two intersecting surfaces in angularly related planes.

References Cited by the Examiner UNITED STATES PATENTS 1,512,342 10/1924 Lengel 101350 1,705,588 3/1929 Sampson 101366 X 1,744,204 1/ 1930 Boisseau 101366 X 1,988,454 1/1935 Lamatsch 101366 2,018,193 10/1935 Smith 101--366 2,081,906 6/1937 Ball 101--366- 2,201,008 5/1940 MacArthur 101366 X 2,206,712 7/1940 Bobson 101350 2,534,320 12/1950 Taylor 117111 X 2,583,640 1/1952 Faeher 101365 2,714,413 8/1955 Hunter 118-410 X 2,802,417 8/1957 Dougon 101365 2,837,024 5/1958 Forbes 101348 X 2,945,436 7/1960 Von Buskirk 101350 2,965,927 12/1960 Crosby et al 118-413 X 3,030,917 4/1962 Brown et a1. 118--413 ROBERT E. PULFREY, Primary Examiner.

E. S. BURR, Assistant Examiner.

Claims (1)

1. IN A PRINTING PRESS HAVING A PLATE CYLINDER, INKING MECHANISM FOR INKING A PRINTING PLATE ON SAID PLATE CYLINDER COMPRISING, A PLATE FROM ROLL HAVING A RESILIENTLY YIELDABLE PERIPHERAL PORTION PROVIDING AN ARCUATE PHERIPHERAL SURFACE DEFINING AN ARCUATE PLANE, SAID FORM ROLL BEING OPERABLE TO RUN IN ENGAGEMENT WITH A PLATE ON SAID PLATE CYLINDER, MEANS SUPPORTING SAID FORM ROLL TO RUN IN ENGAGEMENT WITH SAID PLATE, INK HEAD MEANS COMPRISING A NON-ROTATING FILM FORMING MEMBER HAVING A FILM FORMING PORTION EXTENDING AXIALLY ALONG SAID FORM ROLL, SAID ROLL APPROACHING SAID FILM FORMING PORTION FROM ONE SIDE THEREOF AS SAID ROLL ROTATES, MEANS FOR SUPPLYING INK IN QUANTITY TO SAID ROLL AT SAID ONE SIDE OF SAID FILM FORMING PORTION, SAID FILM FORMING PORTION HAVING AN EDGE PORTION WHICH LEADS SAID FILM FORMING PORTION TO ENGAGE AND INDENT SAID RESILIENTLY YIELDABLE PORTION OF SAID FORM ROLL, AND SUPPORT MEANS FOR SUPPORTING SAID FILM FORMING PORTION IN A POSITION WITH SAID EDGE PORTION DISPOSED RADIALLY INWARDLY OF SAID ARCUATE PLANE TO FORM A SIGNIFICANT INDENTATION IN SAID ROLL ON THE SIDE OF THE LOCATION OF THE INK SUPPLY AWAY FROM THE APPROACH SIDE OF SAID ROLL, SAID SUPPORT MEANS INCLUDING MEANS FOR ADJUSTING AND MAINTAINING THE POSITION OF SAID EDGE PORTION RADIALLY INWARDLY OF SAID ARCUATE PLANE TO ADJUST THE DEPTH OF SAID INDENTATION AND SAID MEANS FOR ADJUSTING AND MAINTAINING THE POSITION OF SAID EDGE PORTION HOLDING SAID EDGE PORTION AGAINST LIFTING BY THE FILM ON SAID ROLL, AND SAID FILM FORMING PORTION COOPERATING WITH THE SURFACE PORTION OF SAID ROLL TO DEFINE SAID INDENTATION AND FORM A THIN UNIFORM INK FILM ON SAID ROLL AS SAID ROLL ROTATES RELATIVE TO SAID FILM FORMING MEMBER.

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