US2915007A - Dampening device for lithographic presses - Google Patents

Description

Dec. 1, 1959 T. H. JOHNSON ETAL 2,915,007

DAMPENING DEVICE FOR LITHOGRAPHIC PRESSES Filed Oct. 17, 1957 s Sheets-Sheet 1 INVENTORS THDMAE 334 5 W JM IEZ'LcR 6 1004; m1) ATTORNEYS Dec. 1, 1959 T. H. JOHNSON ETAL 2,915,007

DAMPENING DEVICE FOR LITHOGRAPHIC PRESSES Filed Oct. 17, 1957 e Sheets-Sheet 2 INVENTORS T l ms Jam/sou Mus l/ER 6am Maw.

Dec. 1, 1959 T. H. JOHNSON ETA!- DAMPENING DEVICE FOR LITHOGRAPHIC PRESSES Filed Oct. 17, 1957 6 Sheets-Sheet 3 INVENTORS /ro/vms fl IRMA/801v 19 77; only \T. M lI5//E R BY 7 ATTORNEYS Dec; 1, 1959 T. H. JOHNSON ETA!- 2,915,007

DAMPENING DEVICE F OR LITHOGRAPHIC PRESSES Filed Oct. 1'7, 1957 6 Sheets-Sheet 4 ATTORNEYS Dec. 1, 1959 T. H. JOHNSON ETA!- 2,915,007

7 DAMPENING DEVICE FOR LITHOGRAPHIC PRESSES Filed 001:. 17, 1957 s Sheets-Sheet 5 TH a ATTORNEYS 7 Dec. 1, 1959 T. H. JOHNSON ETA!- 2,915,007

DAMPENING DEVICE FOR LITHOGRAPHIC PRESSES Filed pct. 17, 1957 s Sheets-Sheet s INVENTORS Z'ZS H-JBMv$am BY Ho/vy T R R ATTORNEYS United States Patent As is Well known in this; art, it is necessary'td'apfly moisture to the printing'plate or printing surfaceipriorito the application of ink thereto." The amount of moisture required varies with printing conditions and depends upon a large variety of factors well known to'thoseskilled in the art.

Theobject of the present inventioni'sto' provide a means for applying a predetermined amount of moisture to the desired surface by'controlling'the location of the ductor roll which is operably interposed between the moisture supply and the printing plate carried by theplate cylinder. p

A further object isto provide 'a? means for controlling the dwell of the ductor on both aipick'up roll and pan roller by novelmechanismjfofmovingand maintaining the ductor in the desired location'with respect to the rolls or rollers with which it normally cooperatesyor inan intermediate .position therebetween.

Another object isto provideimechanism wherebythe ductor may be moved from'itspresent' condition in contact with its cooperating roll or roller, outof contact therewith, and back to its original positionby a remote control of the presentationof adesired camjsurface.

A further object is to provide'a mechanism ofthe character described in'which the dwells of'the ductor in anyone of at least three positions may be secured by the longitudinal displacementin a rightlineof a single cam.

A further object is to providean'apparatus by which the aboveand other objects'may effectively'be attained as will hereinafter appear from the detailed specification which follows.

Broadly, my'invention comprises a dampening device for a lithographic press including apan roll,- aplate cylinder, a plate thereon, a pick up roll and a ductorroll operable to successively contact thepick up roll and pan roll and means for controlling the 'dwell of said ductor roll in at least three positions including in contact with the pan roll, thepick up roll'a'nd' in a position intermediate the two.

Referring to the accompanying'drawings bearing nuparts.

Fig. 1 represents insectional'side elevation and partly in diagram 21 dampening unit constructed according to my invention, the ductor roll contacting the pickup roll.

Fig. 2 represents, partly in section, a side elevationof a unit similar to that shown in Fig.1; the. parts being intheposition they assume when the ductor roll contacts the pan roller.

Fig. 3 represents a dampening unit embodying my invention and similarto that shown in Figs; l and 2 in which the parts. areshown, in sideelevation; partlyin diagram and partly in section,..in the positions. assumed where the ductor roll is. maintained outtof contact with either the pick up roll or pan roller, ire-1; in: an intermediate position from which it may successively. .contacttboth.

Fig. 4 represents a front elevation of one end of the 2,915,007 r" Patented Dec:v l, 1959 ice.

2 cylinders;illustrating the'mounting of same together'with a portion of the means for positioning same.

' Fig. 5 represents an outside end view of the adjusting and biasing mechanism illustrated in Fig. 4.

Fig.- 6 representsafront viewof the means for adjusting the latch lever and means for mounting same; and

Fig. 7 represents adiagram, a side elevation of a modified form of my invention in' which a desired cam surface is'presented to a follower by rocking the cam thru a system of' levers, said system'being that illustrated in Figs. 1, 2 and 3.

As clearly illustrated. in Fig. 1, the usual water pan 1 containing liquid of "the desired mixture of water and small amounts of acid, or-other solutions, is mounted in brackets 2 between'the side frames 3, 4, so as to extend across the full width of the working'or' printingarea of the press.

' The roll 5-, commonly known as the pan roll; is 'rotatably mounted on shaft 16" to extend across said printing area and for rotation while partially immersed in the waterinixture or other solution of pan 1. It W-ill be understood that the pan roll 5 picks up a thin film of the mixture and carries same'on its surface to a point where it is transferred to a second roller 6', known as the ductor rolli- Ordinarily, scrapers 7 (also known as water stops) aremounted in position to contact roll 5 at points where a) minimum ofwater is desiredand said scrapers Tare swingably mounted at 8 as shown in Figs. 1 and 3', the U-shaped end of same being releasably secured to rod 8 by the action of threaded bolt 9 on the ends of the U. Said scrapers may-beswung to inoperative position as desired.

The 'ducto'r' 6,'-normally'- provided with a porus cloth stockingorothersurface adapted to-ca'rry the liquid obtained by its contact with the surface of roll 5, is mounted at its ends on levers'll', the latter being pivoted on shaft 13, mountedin'frames 3, 4*(see Fig. 4). The arm 17, forming'the lower element of lever 11-, extends horizontallyand' longitudinally of the press and is:provided'with a cam follower 18 adapted to ride on the upper surface of wedge shaped cam1-9 whichis slidably'mounted in groove 12 (see Fig. 4). The-motion imparted to thecam follower 18 is transmitted through arms 17 and '11 to-' the ductor 6 as will be more fullydescribed-below.

A pick up roll'20 is mounted'for rotation on a shaft 23, mounted in frames 3 and 4 (on bushings) in position topick up moisture from ductor 6 and transfer same through contact therewith to a pair of rollers 24, 25, surfaced similarly to the ductor 6, said rollers 24, 25 being adapted to transfer the moisture from roll 20 to the 'print ing plate or surface on cylinder '26. Said rollers 24 and 25 are adjustable thru means"27 and 28. Adjustment as above is required in "order to properly set the rollers 24 and 25 to compensate for changes in size thereof due to differences in the conditions under which they operate.

The several elements are actuated as follows:

' Thepan roll 5 and pick up roll 20 are constantly driven through a gear train interconnected with the press drive in the usual manner, their speed being maintained in a fixed relation to the press speed.

Ductor roll 6 and a pair of rollers 24, 25 are driven by surface friction from pan roll 5 and pick up roll 20, respectively, ductor roll 6 alternately contacting the pan roll 5 and pick up roll 20; the pair of rollers 24,- 25 contacting pick up roll 20 and the printing surface on cylindot-26. It should'be' noted that since rolls 5 and 20 are driven at different speeds roll 6 will beaccele'rated and decelerated according tosaid speeds of the respective rolls which itsuccessively contacts.

Mounted at one end of the pan roller shaft 16 is a rotary cam :29 andsaid cam, surface engages, theuupper arm of a cam follower lever 30 thereby actuating said lever 30 which is pivoted on shaft 13 and provided'with an arm 31, which in turn, is connected to a link 32, the latter being itself connected to link 33 (see Fig. 3). Cam 29 is so shaped as to coact with lever 30 to give a sudden drop-off to afford only a minimum contact of the ductor with the pan roll.

Link 33 is pinned at 34 to one end of the link 35, the other end of link 35 being attached to a horizontal pin 36 in wedge cam 19, the latter being mounted for slidable movement in groove 12 (see Fig. 4).

Link 33 at its opposite end is pivoted to the lower end of latch lever 37 by a pin 38.

Said latch lever 37 is notched at itsupper end at 39 and 40, said notches being located to receive the manually releasable finger 41 adapted to hold the lever in a predetermined position according to the notch engaged by said finger. The lever 37 is so constructed as to be held in a position intermediate those notches when the said lever is engaged by a spring biased plunger 62 operable on the outside of the frame as shown in Fig. 6. The lever 37 may be moved to its desired position by means of its handle 10 around its pivot 43, it being understood that motion of lever 37 changes the angular relationship between pivots 38 and 34 and hence moves link 33, lever arm 35 and cam 19, as arm 35 is attached to the horizontal cam pin 36.

Cam 19 is thereby caused to be moved in a right line whereby a different cam surface is presented to follower 18. From the connections of follower 18 with arm 17 and lever 11, thechange in travel of the follower is transmitted to the ductor 6, so that the actions of the latter are determined by the operative positions of cam 19.

For example, when the lever 37 has its notch 39 engaged by the finger 41, follower 18 rides on the flat upper surface of cam 19, as shown in Fig. 2. Since the follower is beyond the limit of the low, or slanting nose, on said cam the ductor roll 6 will stay in contact with the pan roll 5.

When the lever 37 has its notch 40 engaged by finger 41, the cam 19 is so positioned that follower 18 rides on the low surface, or slanting nose, thus permitting the ductor roll 6 to remain in contact with the pick-up roll 20 (Fig. 3).

When lever 37 is located in a position intermediate those just described (as shown in Fig.3), cam 19 is positioned so that follower 18 rides both the high and low cam surfaces thereby imparting the desired motion to ductor 6 whereby it is caused to successively contact rolls and 20 for the purposes set forth above.

In this latter position a screw bolt 44 may be manipulated whereby lever 37 is rocked on its pivot, the position of pin 38 is moved, and through the linkage described above, cam 19 is moved in a right line whereby the surface of same presented to the cam follower 18 transmits the desired effect to ductor roll 6, i.e., its dwell on rolls 5 and 20 is controlled by being increased or decreased on either as desired.

of cranks 53, connected by arm 54 and 55, to links 56 and Said movement of pin 38 is caused by the turning of lever 37 on pivot 43 and change the location of pivot 38.

A spring 45 is so located as to normally urge the cam follower 18 toward the lower or inclined portion of cam 19 as it serves to bias rod- 46 and arm 47, secured thereto as shown in Fig. 5, arm 47 being mounted on shaft 13.

In the modified form of my invention as diagrammatically illustrated in Fig. 7 the rolls shown are pan roll 50, ductor roll 51, the pick up roll 52 transfer rolls 24, 25 and printing cylinder 26. The pan roll and pick up roll are driven from the press and in timed relation therewith; the ductor getting its drive from these two driven rolls in the usual manner, i.e., by contact therewithas above described.

v In this instance the ductor roll 51 is mounted in a pair 57, which correspond to levers 33 and 35 of the preferred form heretofore described. The link 57 is connected to a pin 58 in rocking cam 59 which is adapted to present the desired cam face to follower 60 carried in one arm 61 of the bell crank pivoted at 13, arm 53 of said bell crank carrying the mounting for ductor roll 51. As set forth above the location of follower 60 on cam face 59 will control the actions of the ductor, said cam being rockable through the system of links 56, 57 connected to 37.

It will be seen from the foregoing that I have provided a mechanism ofthe type described which is capable of maximum flexibility and fine adjustment, and which is comprised of parts tending to minimize costs.

Since it is evident that various changes may be made in the construction from and arrangement of the several elements without departing from the spirit and scope of my invention, I do not intend to be limited to the specific embodiments herein shown and described except as set forth in the appended claims.

What we claim is:

1. In a rotary printing press, in combination, a cylinder, means for driving said cylinder, a printing surface carried thereby, at least one roller in contact with said surface, a distributing roller contacting said first named roller, a liquid conveying roller and an adjustable ductor mounted for movement between said distributing and liquid conveying rollers and driven therefrom, means for driving said distributing and conveying rollers at predetermined speeds relative to the speed of the printing cylinder, a longitudinally movable cam means for cyclically moving it, means cooperating with the cam and ductor for moving the latter when the cam is moved, and means actuated by said cam controlling the motion of said ductor.

2. An apparatus according to claim 1 in which the cam is slidable longitudinally.

3. An apparatus according to claim 1 in which the cam is slidable longitudinally in a right line.

4. An apparatus according to claim 1 in which the cam is slidable longitudinally, and the means for sliding the cam comprises at latch lever for initially holding the cam in any one of at least three positions namely, with the ductor in contact with the distributing roll, or in contact with the liquid conveying roll, or in an intermediate position out of contact with either of said rolls.

5. An apparatus according to claim linwhich the cam is rockable longitudinally to present the desired cam surface to said means for controlling said ductor motion.

6. In a rotary printing press, in combination, a cylinder, a printing surface thereon, at least one roller contacting said surface, a distributing roller contacting said first named roller, a fountain roller, a ductor means for oscillating it between said distributing roller and said fountain roller and means for controlling the throw of said ductor between said distributing and fountain rollers, said last named means comprising a cam driven with said fountain roller a rock lever actuated thereby a latch lever, a system of links connected with said rock lever and latch lever, a second system of links connected to said latch lever, a second cam connected thereto through said second system, both lever systems being interconnected, means for changing the throw of said second llever system, whereby said last named cam is shifted longitudinally and means for maintaining the latch lever in any one of three positions, namely with the ductor in contact with the fountain roller or in contact with the distributing roller, or in an intermediate position out of contact with either of said rollers.

7. An apparatus according to claim 6 in which the means for changing the throw of said second lever system comprises a preset latch lever and an outer lever, said outer -lever being mounted on the same pivot shaft as the latch lever and a fine adjustment means connected to said outer lever for swinging same on said common pivot whereby said latch lever is rocked on said pivot.

8. An apparatus according to claim 6 in which the means for changing the throw of said levers comprises operatively connected inner and outer levers, the parts being so constructed and arranged that the position of the inner lever is changed by the subsequent change of the outer lever.

9. A structure according to claim 6 in which the means for maintaining the latch lever in anyone of three positions comprises an inner finger and an outer spring biased plunger.

10. An apparatus according to claim 6 in which the cam driven with the fountain roller and the arm actuated by said cam are so constructed and arranged that the arm is abruptly actuated by said cam.

11. An apparatus according to claim 6 in which means are provided for shifting the last named cam longitudinally, said means comprising an adjustable inner lever, means for maintaining said lever in its adjusted position, and another means for adjusting said lever while in its adjusted position.

12. An apparatus according to claim 6 in which the means for changing the throw of said levers is operable only when said ductor roller is in a position intermediatev 10 the distributing and fountain rollers.

References Cited in the file of this patent UNITED STATES PATENTS 1,683,243 Blaine Sept. 4, 1928 15 2,165,235 Curtis July 11, 1939 2.425,643 Royer Aug. 12, 1947 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No, 2,915,007 December 1, 1959 Thomas H, Johnson et a1.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correct-ion and that the said Letters Patent should readas corrected below.

Column 4, line 32, after "cam" insert a comma; line 35, after "cam" insert for Signed and sealed this 24th day of May 1960,

(SEAL) Attest:

KARL H AXLINE ROBERT C. WATSON Attesting Oflicer Commissioner of Patents

Images