US2841081A

US2841081A - Inking mechanism for high-speed cylinder printing presses

Info

Publication number: US2841081A
Application number: US441546A
Authority: US
Inventors: Kaufmann Kurt
Original assignee: HINNIGER AUTOMATIC DRUCKMASCH
Current assignee: HINNIGER AUTOMATIC DRUCKMASCH
Priority date: 1954-07-06
Filing date: 1954-07-06
Publication date: 1958-07-01
Anticipated expiration: 1975-07-01

Description

July 1, 1958 K. KAUFMANN mxmc MECHANISM FOR HIGH-SPEED CYLINDER PRINTING PRESSES Filed July 6, 1954 3 Sheets-Sheet 1 A orneys by A July 1, 1958 K. KAUFMANN 2,841,031

mxmc MECHANISM FOR HIGH-SPEED CYLINDER PRINTING PRESSES 3 Sheets-Sheet 2 Filed July 6, 1954 Jui 1, 1958 Filed July 6. 1954 K. KAUFMANN INKING MECHANISM FOR HIGH-SPEED CYLINDER PRINTING PRESSES 3 Sheets-Sheet 3 llll l lllllll i II .v vlll l nll Fig. 4

-- printing cycle refurn movemen!-- inking by roll 28 inking by roll 58 inking by roll 58 In ven for: KKcz ufmann b m Q q Atfornep Unite INKING MEQHANESM FOR HIGH-SPEED CYLINDER PRINTWG PRESSES Application July 6, 1954, Serial No. 441,546

8 Claims. ((11. 101-353) This invention relates to an inking mechanism for highspeed cylinder printing presses, and more particularly high-speed stop-cylinder printing presses, having two groups of rolls each comprising a form inking roll, and has for its object to provide an inking mechanism which permits faultless inking of printing forms having a configuration which renders them difficult to ink, and more especially of flat forms comprising recessed or cut-out portions.

Inking units are known which comprise two form inking rolls each driven independently of the form carriage with a speed higher than that of the average carriage speed, the speed of the rolls being modified to that of the carriage during the inking process. In an inking mechanism of this kind the circumference of the form inking r-olls must correspond to the greatest possible length of the printing form. Due to the fact that these inking mechanisms are driven at a substantially uniform speed, the form inking rolls can ink the form only once per printing cycle, and must be lifted off the form during the return movement of the latter. Consequently, the two form inking rolls ink the form in two subsequent stages.

With forms requiring a great quantity of ink, application of the ink film in two stages is disadvantageous, because in this case the form inking rolls must carry a relatively thick film of ink which tends to clog the form. In order to obtain uniformly clean prints, the form must be frequently cleaned which every time necessitates a longer standstill of the machine and consequently has a detrimental eifect on production. Moreover, there is great danger of fouling the fresh prints, due to the fact that printing must be done with a thick film of ink. If the ink film would be applied to the form in three stages, it would be possible to use a much thinner ink film on the form inking rolls which would greatly reduce the tendency of clogging the form. This would mean, however, that an inking unit of this type would have to be provided with three form inking rolls. A printing press working with three big form inking rolls the circumference of each of which corresponds to the maximum length of the form, would be much more expensive to build, due to the fact that such a machine would require a longer carriage travel, and consequently would have to be provided with a larger printing cylinder and with a longer machine frame.

The invention provides the possibility of producing a faultless and uniform three-stage ink film on the form, using but two form inking rolls. An important feature of the invention resides in the fact that the group of rolls comprising the one form inking roll is driven independently and continuously, while the group of rolls comprising the other form inking roll is driven forwardly and backwardly by the carriage. In the context of this specification, an independent and continuous drive of the one form inking roll inking the form only in one direction, means a drive working independently of the carriage at a substantially uniform speed which is higher than the grates Patent as ilfi i patented July 1, 1958 average speed of the carriage, the speed being modified to that of the carriage during the inking process.

For improving the breaking up of ink as regards the forwardly and backwardly rotating form inking roll which inks the form in both directions the invention further provides at least two saturation points each formed by a distributor roll, which are associated with said form ink ing roll.

According to a preferred embodiment of the invention, both groups of rolls may be connected by a pendulously arranged break-up roll in the range in which they operate at equal speeds, also, the drive of the continuously rotating form inking roll may be taken off the crank and slot mechanism driving the front delivery mechanism of the machine, whereby the cost of construction of the machine .is substantially reduced. Another important feature of embodied, by way of example only, in a high-speed stopcylinder printing press.

Fig. 1 is a side elevation in diagrammatic view of a V printing press embodying the inking mechanism according to the invention;

Fig. 2 is an enlarged side elevation of the inking mechanism showing both applying rollers in ink applying position;

Fig. 3 is a plan view of the inking mechanism comprising various sectional views arranged in a common plane;

Fig. 4 is a speed diagram, and

Fig. 5 is a view similar to Fig. 2 but with one applyving roller raised as the carriage moves rearwardly.

The carriage 2 carrying the printing form 1 is reciprocated in the usual manner by a pinion 3, connecting rod 4 and crank wheel 5. The printed sheet is removed from the printing cylinder 6 by the chain delivery mechanism 7 which comprises two gripper bears, 8.-'

The chain delivery mechanism is continuously driven at a non-uniform speed which is governed by the speed i with which the printing cylinder rotates at the moment of sheet transfer. On the crankshaft 9 is mounted a gear 10 meshing with a crank wheel 11 which carries a roller pin 12 engaging in a slot 13 of a wheel 14, the

center of which is offset in relation to the center of crank wheel 11. While wheel 11 rotates continuously at uniform speed, the wheel 14 revolves at a non-uniform speed, its rotational movement being transmitted by an idler gear 15 to the wheel 17 secured on the shaft 16 of the chain delivery mechanism. By properly selecting the center distance of the two wheels 11, 14 relative of each other, as well as the form of the cam profile 13,

the speed of the chain delivery mechanism is modified in such a manner, that during removal of the sheet from the printing cylinder 6 it corresponds with the speed of the latter. a sprocket 18 is mounted (Fig. 3), which via a chain 19 drives the sprocket 21 secured on the inking cylinder shaft 20. Mounted rotationally fast on the shaft 20 by means of a key 22 is an inking cylinder 23 which together with the two break-up rolls 24 and 25 (Figs. 1 and 2) constitutes the continuously rotating group of inking rolls.

The fresh ink required per print is taken off from the fountain roll 27 running in the ink fountain, by a pick-up roll 26 and transferred to the continuously rotating break-up roll 25. The'form inking roll 28 cooperating with the inking cylinder 23 is supported for pivotal carried by arms 30 capable of pivotal movement about On the shaft 16 of the delivery mechanism the central axis of inking cylinder 23. The form inking roll arms 30 are constantly urged in a direction towards the printing form by compression springs 31. On the form inking roll arms 30 is further provided a cam 32 which carries a set screw 33 abutting against a segment member 34 bearing in turn against a rotatable square member 35. The segment member 34 is also supported for rotational movement about the central axis of the inking cylinder 23. The height of the form inking roll relative to the form may be adjusted by means of the set screw 33, while the distance between form inking roll and inking cylinder can be set by adjusting the bearings 29 (Fig. 3).

Since the form inking roll will ink the form only in one direction, it must be raised prior to the second passage of the form. This is effected in a simple manner by turning the square member 35 (Fig. 2). Thereby a small amount of left-hand rotational movement is imparted to the segment member 34, which via the screw 33 is transmitted to the form inking roll arms 30 swinging them about the central axis of the inking cylinder in an upward direction, so that the form may freely pass below the form inking roll 28. Rotation of the square member 35 is derived from the pick-up and ductor roll as follows:

The crankshaft 9 carries a crank pin 36 which through connecting rod 37, bell crank lever 38 and link 39 reciprocates a segment lever 41 mounted on the pick-up roll shaft 40. On the one hand, this reciprocation operates the pick-up roll 26, and on the other hand controls the ink fountain roll 27 in a manner not shown. The segment lever 41 comprises a cam segment 42 on which runs a roller 43 mounted on a lever 44 which is fixed directly on the shaft of the square member 35. The cam profile of the segment 42 and the timing are so chosen, that the roller 43 rides on the low part of the cam segment 42 when the form inking roll 28 is supposed to ink the form. Upon rotation of the cam segment 42 in a clockwise direction, the roller 43 rides up the higher part of the cam profile, whereby the square member 36 is being turned and the form inking roll 28 lifted off the form.

The machine further comprises a forwardly and backwardly running group of rolls arranged around the steel distributor roll 51 (Figs. 1 and 2). This group comprises a break-up roll 55 and a steel roll 56 pivotable about said break-up roll, as well as another break-up roll 57 arranged for pendulous movement about the steel distributor roll 51. The form inking roll 58 associated with this group of rolls is supplied with fresh ink by the steel distributor 51 as well as by the steel roll 56.

The break-up roll 57 is supported in levers 59' (Fig. 3) pivotable about the central axis of the steel distributor roll 51 and connected with lever 44 by a link 60.

Parts

60 and 59 were omitted on the left side of Figure 3 in order to avoid what would be a complicated showing in the drawing. A torsion spring 61 constantly urges the break-up roll 57 against the inking cylinder 23.

The forwardly and backwardly rotating group of rolls is driven from the carriage rack in the usual manner as follows: The gear 47 running on a flange 46 engages with the rack 45 (Fig. 1) and transmits the forward and backward rotation to the gear 48 mounted on the cylinder shaft 20 (Fig. 3), which in turn drives the gear 50 of the steel distributor roll 51 through an intermediate gear 49., The gear 48 does not only serve the purpose of positively transmitting the forward and backward movement to the steel distributor roll 51, but is also employed for lateral breaking-up of the ink on the inking cylinder 23; for this latter purpose the gear 48 is provided with an internal thread engaging with a corresponding thread of the fixed bearing sleeve 52. In an axial direction, this gear 48 is connected with the inking cylinder 23 by means of the ball bearing 53, since the inner race of said ball bearing 53 is secured on the gear 48 and the outer race within the inking cylinder 23, by means of a ring nut 54. Consequently, the inking cylinder 23 can execute the rotational movement imparted to it by the shaft 20, while the gear 48 reciprocates the cylinder 23 laterally in an axial direction by means of its internal thread and its forward and backward rotation.

Figure 2 illustrates the parts in the position in which the applying roller 28 rests on the type form. In this position roller 57 abuts inking cylinder 23.

When the roller 43 (Fig. 2) rides up the high portion of the cam segment 42, this has not only the effect of lifting the form inking roll 28 olf the form due to the linkage described earlier, but also brings the break-up roll 57 out of engagement with the inking cylinder 23. When the roller 43 in its travel along the peripheral edge of the cam segment 42 reaches the lower portion of the cam profile, the form inking roller 28 is lowered on the form, and simultaneously the break-up roll 57 is brought into engagement with the inking cylinder 23, where it takes up the already well broken-up and distributed ink, feeding it to the forwardly and backwardly rotating group of rolls. During this period both groups of rolls rotate at the same speed.

In Figure 5 the parts are illustrated in the lower terminal position. The guide link 39 has risen and in doing so has swung the cam segment 42 about pick-up roll shaft 40. The cam segment 42 thereby has pressed roller 43 somewhat downward so that lever 44 and square member 35 are swung counterclockwise. By means of link the lever 59 is swung somewhat counterclockwise so that break-up roll 57 is lifted from inking cylinder 23.

Square member 35 by its rotation has acted on projection 34 and thereby caused a left turn of segment 34 so that also projection 34 is turned and through screw 33 and arm 32 the inking roll arms 30 and thereby the inking cylinder 28 are lifted from the type form 1.

In the speed diagram shown in Fig. 4, the sine curve drawn in broken lines represents the movement diagram of the form I mounted on the carriage. The curve drawn in full shows the non-uniform speed to which the uniform speed is converted by the crank and slot mechanism, and at which are driven the gripper chains of the sheet delivery mechanism as well as the continuously rotating group of rolls of the inking unit. As may be seen from the diagram, the uniform speed requires only a slight modification for partial adaptation to the carriage speed, due to the fact that the position of the form inking roll 28 relative to the carriage movement is such, that the middle of its inking period is situated approximately at the apex of the sine curve of the carriage movement. The middle of the inking period of the form inking roll 58 which is driven exclusively according to the sine curve of the diagram, is situated well ahead of the apex of the sine curve of the carriage movement during the printing cycle, and well behind said apex during the return travel of the carriage, as is usual practice. The three inking sections shown in the diagram correspond to the application of an ink film to the form in three stages.

The speed of the continuously rotating groups of rolls is so chosen, that the form inking roll 23 executes slightly more than 5 revolutions per print, which in the present case are fully available for equalizing all weakly and strongly inked spots that have been produced by the single contact with the form. Consequently, the form inking roll 28 will have a completely uniform ink film after 5 revolutions which is just as uniformly transferred to the printing form due to the fact that the circumference of said form inking roll corresponds to the greatest possible length of the form.

The forwardly and backwardly rotating group of rolls being connected with the continuously rotating group of rolls by the break-up roll 57 during the inking period of form inking roll 28, it will receive a completely uniform fresh ink film from said break-up roll. Even though the inking roll 58 which inks the form during forward and backward travel, continuously transmits weakly and strongly inked spots to this group of rolls, the inequalities in inking produced on the form inking roll 58are eliminated twice as quickly and efficiently by the two saturation points constituted by the

steel distributors

51, 56, than would be the case with single saturation, so that this form inking roll, the circumference of which also corresponds to the greatest possible length of the form, will likewise apply an approximately uniform two-stage ink film to the form.

The inking process per printing operation is as follows: During the return movement of the carriage the form 1 receives the first ink application from the roll 58; during the subsequent printing cycle it will receive the second application also from roll 58, and immediately after this the final and third ink coating of absolute uniformity from the roll 28. Consequently, an inking mechanism constructed in the manner and with the combination described in the foregoing will, without the machines stroke being increased, assure a quality of inking that can never be obtained with a forwardly and backwardly rotating inking unit of usual construction, and which with inking rolls inking but in one direction could be achieved only by substantially increasing the stroke of the carriage, which would entail a considerable increase in cost.

The direction of rotation of the roll 28 is so chosen, that it will ink the form when it enters the printing cycle. This is not absolutely necessary, but was considered convenient only because of the fact that in this case the drive of the sheet delivery mechanism can be used to operate the continuously rotating group of rolls. Provided that a separate drive is provided, the adaptation of the speed of the continuously rotating inking roll group to the movement of the form may, of course, be also effected during the return movement of the carriage, i. e. the inking may be accomplished during this period; This will depend solely on the design of the machine, respectively on the principle according to which the high-speed printing press is constructed. It will be noted that the inking mechanism according to the invention may also be applied to a high-speed swinging cylinder printing press or to a single or two-revolution printing press, provided that one group of rolls of the inking unit is driven at a speed higher than the average carriage speed, it being possible to connect this group of rolls, for example, to a driving unit required for this type of machine.

I claim:

1. An inking mechanism for high-speed cylinder printing presses, and more particularly for high-speed stopcylinder printing presses, having a carriage adapted to support a printing form for forward and backward movement, said inking mechanism comprising a first group of co-operating rolls including a first single form inking roll adapted to be driven independently and continuously, means for lifting said first form inking roll from said printing form during backward movement of said printing form, and a second group of co-operating rolls comprising a second single form inking roll and adapted to be driven forwardly and backwardly by said carriage.

2. An inking mechanism as set forth in claim 1 comprising at least two distributor rolls associated with said second single forwardly and backwardly rotating form inking roll and constituting saturation points for said second form inking roll.

3. An inking mechanism as set forth in claim 2 including a break-up roll arranged for oscillatory movement and adapted to connect said first and said second group of rolls during a period in which both of said groups rotate at the same speed.

4. An inking mechanism for high-speed cylinder printing presses, and more particularly for high-speed stopcylinder printing presses having a carriage adapted to support a printing form for forward and backward movement, and a sheet delivery mechanism, said inking mechanism comprising, a first group of co-operating rolls including a first single form inking roll and adapted to be driven independently and continuously in one direction of rotation, means to bring said first single form inking roll into contact with said printing form during forward movement only of said form, a second group of co-operating rolls including a second single form inking roll and adaptedto be driven forwardly and backwardly by said carriage, and a slot and crank mechanism adapted to drive said first continuously driven form inking roll from said sheet delivery mechanism, the speed of said sheet delivery mechanism, being modified by said slot and crank mechanism, corresponding to the inking speed.

5. In an inking mechanism for high speed stop cylinder presses, a carriage adapted to support a printing form for backward and forward reciprocating movement, two roller groups each including a single form inking roller, each form inking roller having a circumference which corresponds substantially to the maximum printing form length, one inking roller being driven continuously, means for lifting said one inking roller from said printing form during backward movement of said printing form, the other inking roller being driven with said carriage alternately forwardly and backwardly.

6. In an inking mechanism as claimed in claim 5, ink being supplied to said other inking roller by at least two rubbing rollers.

7. In an inking mechanism as claimed in claim 5, said two roller groups being connected through a raisable rubbing roller during the time when both supplying rollers are supplying ink to the type form.

8. In an inking mechanism as claimed in claim 5, said two roller groups being supplied with ink by a common inking cylinder driven continuously in one direction of rotation, and means whereby said common inking cylinder is reciprocated axially by the reciprocatory motion of said carriage.

References Cited in the file of this patent UNITED STATES PATENTS 1,073,836 Barber Sept. 23, 1913 1,971,081 Newton et al. Aug. 21, 1934 2,170,027 Kaufmann Aug. 22, 1939