US2083497A - Roller attachment for lithographic machines - Google Patents

Description

June 8, 1937. y R. c. DIX

ROLLER ATTACHMENT FOR LITHOGRAPHIC MACHINES Filed Oct. 18, 1955 2 Sheets-Sheet .1

INVENTOR, I, Ral h an,

BY D TTORNEY. I

June 8, 1937. R. c. DIX 2,083,497

ROLLER ATTACHMENT FOR LITHOGRAPHIC MACHINES Filed Oct. 18, 1935 2 Sheets-Sheet 2 INVENTOR,

Ral 0. D19,

Patented June 8, 1937 PATENT OFFICE ROLLER ATTACHMENT FOR LITHOGRAPHIC HINES V 1 MAC Ralph C. Dix, New York, N. Y.

Application October; 18, 1985, Serial No. 45,629

7 3 Claims. (01. 10 1351) This invention relates generally to machines for printing, and more particularly to an ink distributing roller attachment for lithographic machines.

The main object of this invention is the provision of an auxiliary ink distributing mechanism which may be appended to previously existing lithographic machines or incorporated during the construction of new lithographic machines.

I-Ieretofore difficulty has been experienced with lithographic machines in properly applying a coating of ink to the lithographic plate ,therein. This has been encountered especially where the 5 lay-out of the printed page contained great variation in distribution, as for example where halftones or line drawings are interspersed withrlight face type. Under such conditions if too much ink is used the half-tones are too dense and lack contrast while ink is carried into the white space about the type, and on the other hand, insufficient inking results in grayish blacks and flat half-tones with occasional water streaks and ghosts.

Through the utilization of the present invention, the above mentioned difficulties are remedied and a lithographically printed sheet of paper is produced in which are found brilliant halftone pictures, and dense, even-laying blacks of type matter and solids.

Another object of this invention is the provi sion of structure of the class described which is simply attached to the lithographic press, and expeditiously detached for cleaning or adjustment.

A further object of the invention is the provision of structure whereby the same may be dismantled for cleaning and then quickly and easily reassembled without disturbing the previously adjusted inter-roller pressures thereof.

A still further object is the provision of structure whereby greater ink distribution is secured at all speeds and adequate ink distribution is obtained at considerably higher press speeds, so that the ink lies flatter; more densely'and uniformly. The efiiciency of a hand ink fountain,

is also increased, while the operation of an automatic ink fountain is not interfered with.

Because of the reduced pressure of the form (lithographic plate contacting) rollers against the lithographic plate, the latter gives longer runs, and the life of the rollers is increased with a concurrent reduction in stress on the related machine parts and bearings. The additional rollers also reduce the occurrence of water streaks and ghosts. 7

These objects and further ends and advantages will more fully appear in the progress of this disclosure and as pointed out in the appended claims.

- In the accompanying drawings:

Figure 1 is a fragmentary View in perspective showing the invention. as applied to a rotary lithographic printing press.

Figure 2 is a fragmentary view in perspective of the attaching brackets comprising split collars fastened to a tie bar of the'lithographic machine.

Figure 3 is a vertical sectional view taken transversely of the attachment, looking inwardly thereof and viewed from a plane immediately inwardly of therright hand frame plate, as viewed in Figure 1. v

-Figure'4 is afragmentary sectional View of Figure 3 taken along the plane 4-4 thereon.

The chassis of this roller attachment is comprised of a pair of vertical and parallel opposed plates [0 and H which are maintained in spaced inter-relation by a pair of transverse tie-rods i2 and I3. The plates I0 and II are of irregular shapeand the configuration thereof will be more particularly set out below. Tie-rods l2 and I3 are suitably affixed therebetween as for example by thefiat headed machine screws penetrating countersunk orifices in said plates and engaging the internally threaded ends of the said rods.

Numeral l4 designates a heavy transverse tie rod which is part of the structure of the main rotary lithographic press generally indicated by numeral [5. Tie rod l4 supports and spaces the two vertical side walls I6 and ll of press l5, and said rod also carries the chassis of the roller attachment by means of two inwardly offsetlugs I 8 resting'thereon. Lugs l8 are integral'lateral projections from the plates I0 and l l at the lower edges thereof and are of a suitable shape preferably curved so that the under surfaces thereof saddle upon the upper surface of the tie bar I4 while the upper surfaces'of said lugs are adapted to fit beneath a pair of lugs l9, which are integral with and outwardly ofiset from the upper halves 20 of a pair of split collars 2|. Collars 2| are affixed to the tie rod [4 by means of the clamping action obtained when the screws 22 arejtightened. Screws 22 freely penetrate the upper halves, 20 and threadedly engage the lower halves of the split. collars 2| as best seen in Figure 2 of the accompanying drawings. The collars 2| are so spaced along the rod l4 that the the. outer vertical surfaces of the upper halves as seen in Figure 4.

It may now be seen that the chassis of the roller attachment is mounted upon rod M by placing lugs l8 thereon forward of lugs I9 or to the right thereof as viewed in Figure 3 and then circumferentially shifting the said chassis until the lugs l8 are under lugs|9 as shown in Figure 4. In the. procedure .just .outlined the inking head 3| is tilted to allow sufficient clearance. in position with the lugs l8 and. L9 interlocked by means of a pair of braces 23 whichlimit the rotational displacement thereof about rod M.

The pivotal ends of braces 23 are integrally and radially mounted in collars 24 in turn piv otally mounted on extensions25which are affixed Tie b .26

to the outer ends of a tie bar 26. is one of the transverse members of the inking head 3| on the press |5. Extensions 25 are comprised of a collar portion having a set screw which engages theend of the tie rod inserted therein'anda reduced position which penetrates collars 24, the latter being retained thereon by a washer and cotter pin 21. Each of the other ends of braces 23 are threaded-for a substantial portion thereof and said ends freely penetrate blocks 28 which are fixed therealong by means of nuts on said braces which are drawn up against both sides of said blocks. Blocks 28 are mounted uponposts 29 which extend outwardly and 'perpendicularly from plates IOand 1|." The outer terminals of posts 29 areinternally threaded to receive wing bolts 30, said bolts penetrating transverse orifices in blocks 28. v

' The form roller 32 is comprised of an outer cylinder 33 of a resilient material, preferably rubber, which is mounted in turn upon a rigid cylinder rotatably carried by means of bushings upon a shaft 34. Shaft 34 has the terminals thereof flattened so that it is capable of displacement along the slots 35 which are formed in the lower edge of plates l0 and II, the configuration of said plates being best seen in Figfor vertical displacement in the slots 39 An intermediate roller 40 is constructed simi larl'y to roller 32, and is mounted rotatably on a transverse shaft 4|. The terminals of 'shaft 4| abut the inner faces of plates I0 and H and are not journaled therein. Roller 40 is thus main tained in operative position by riding upon the rollers 32 and 31.

cylinder preferably brass, and is rotatably mounted on'a transverse shaft 43. Shaft 43 has the ends thereof flattened and is adapted for vertical displacement Within the slots 44 in the plates 10' and; Roller 42 is of the transverse oscillating type ,well known in the printing art having internal cam ways. which cooperate with studs projecting proportionately from shaft 243 within said roller. In normal operation the roller 42 rests upon the roller 40..

The relativeinter-roller pressures'are reg lated by means of structure'nowfto be described.

' A pair of irregularly'b'ent clips 45"are adapted f The roller attachment chassis is secured to {properly center the same. provided with collars corresponding to the collars 52 just mentioned because the lateral disstuds 41 and resnapped 'by' the rod 2.

ink distributing roller 42 has a rigid outerby means of the upturned lower ends 46 thereof to hook under a pair of inwardly projecting studs 41 extending off the inner faces of plates I0 and The upper ends of clips 45 are curved as indicated by numeral 48 and are adapted to frictionally and resiliently engage the tie rod I2. The general configuration of the clips 45 is best seen in' Figure 3. Each of the clips 45 is provided with three screws 49, 50 and 5|, which are adapted 'to bear against the upper surfaces of the extremities of shafts 43, 4| and 38 respectjYBly. Each of the last mentioned screws is provided with suitable locking means as, for example, with knurled nuts as shown. Each of the shafts 34, 4| and 38 is provided with a pair of'collars 52, which are fixed thereon at either side of the corresponding rollers and which serve Shaft 43 is not clips may be unhooked from the studs 41, and

the rollers 42, 40 and 31 maybe conveniently removed for cleaning since it is unnecessary to disturb the adjustment of the screws 49, 50 and sun this process. When these rollers are replacedthe clips are merely hooked under the The pressures existing between the various rollers will now' be the same I as before the cleaning operation was undertaken.

The roller 31 contacts the roller 53 which is preferably'a rubber roller and is one of a series of rollers in the inking bead 3|. As indicated on Figure 3, ink is deposited upon a roller 54, which is preferably a rubber roller of the oscillating type. Roller 55 is preferably steel and serves to evenly distribute the ink, on roller 54.- Ink travels from roller 54 to roller 53 and thence in two directions. 56, preferablyrubber, to the lithographic plate 51 mounted upon the main cylinder 58 of the press I5. The other route of ink travelling from roller 53 is by way of rollers 31, 40 and 32. The last mentioned roller delivers ink to the litho graphic plate 51. The roller 42 being of the oscillating type serves to uniformly spread the ink on roller 40.

It maynow be seen that ink is deposited upon the lithographicplate 'at two separate points, andsince the'ink delivered on said plate is thus divided, not only is the distribution thereon more uniform, but'the pressure of rollers 56 and 32 thereagainst can be considerably reduced. By manipulation of the settings of the various shafts 34, 38,41 and 43, which is easily accomplished by means of set screws 36 and screws 49, 50 and 5|, the inter roller pressures may be so arranged that the ink is transferred in a highly efficient- ,iliary inking device into proper position, as before explained, because the roller attachment brace 23 would interfere with a standard short handle; g I wish it distinctly understood that minor va- One route by way of a roller riations in the materials, construction and disposition .of the various parts of this invention may be introduced without departing from the spirit of the invention and the scope of the following claims.

I claim: V

1. The combination with a rotary lithographic printing press, comprising an inking head, a cylindrical lithographic plate and a frame tie bar; .of a detachable auxiliary inking device for diverting a part of the ink from the inking head, serving the lithographic plate, to a separate circumferential portion of said plate, said device comprising a pair of split collars, provided with offset lugs and spacedly clamped around said tie bars, two chassis plates with lugs interlockingly engaging the aforesaid lugs, a set of ink-transferring rollers journalled between the chassis plates and a pair of adjustable braces, adapted to tie the free-swinging ends of the chassis plates to the frame structure of the inking head at a proper angle for operative contact of the auxiliary inking device with'the inking head and they lithographic plate.

2. In a rotary lithographic printing press, comprising an inking head and a cylindrical lithographic plate, a detachable auxiliary inking device for diverting a part of the ink from the inking head, serving the lithographic plate, to a separate circumferential portion of said plate, said device comprising a pair of chassis plates, a set of ink-transferring rollers loosely journalled be tween these chassis plates, detachable means to pivotally fasten and hold said chassis plates on the frame of the press in proper contacting position of the set of rollers relative tothe inking so that the inter-roller pressure may be regulated thereby.

3. The combination with a rotary lithographic printing press, comprising an inking head and a cylindrical lithographic plate, inked by'said head;

of a detachable auxiliary inking device for diverting a part of the ink from said inking head to a separate circumferential portion of said plate,

said auxiliary device comprising a pair of chassis plates, pivotally and adjustably held on the frame structure of the press, an ink pickup roller, adjustably'journalled in the chassis plates so as to contact one .of the inking head rollers, a form roller, adjustably journalled in the chassis plates, apart from the pickup roller and so as to contact the cylindrical lithographic plate, and an intermediate transfer roller, floatingly supported by the pickup and the form roller, with unjournalled offset free ends and means to limit the upward free motion of said intermediate roller, said means comprising adjustable stops, adapted to contact the unjournalled offset ends of the roller, said stops mounted on the chassis plates.

RALPH C. DIX.

Images