GB1578801A

GB1578801A - Liquid applicator device

Info

Publication number: GB1578801A
Application number: GB2626577A
Authority: GB
Original assignee: Polygraph Leipzig Kombinat Veb
Current assignee: Polygraph Leipzig Kombinat Veb
Priority date: 1976-07-02
Filing date: 1977-06-23
Publication date: 1980-11-12
Also published as: DE2720371A1; SE7707668L; DD128382A1

Description

(54) A LIQUID APPLICATOR DEVICE (71) We, VEB POLYGRAPH LEIPZIG KOMBINAT FUR POLYGRAPHISCHE MASCHINEN UND AUSRUSTUNGEN, of Zweinaundorfer Str. 59, 705 Lepizig, German Democratic Republic, a corporation organised under the laws of the German Democratic Republic, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed to be particularly described in and by the following statement-: The present invention relates to a liquid applicator device for a printing machine.

Means are known for discontinuously driving a ductor element in an inking mechanism of a printing machine, in which a stepless variation of the angle of rotation is possible during the running of the machine through a coupling linkage movable by a crank drive and with an input and output rocker, in which the output rocker has a pivot point of variable location (United Kingdom Patent Specification No. 936981). Such devices have the disadvantage, that a variation of the metering, especially with a small ink feed, through displacement of the ductor blade becomes effective only after a multiplicity of ductor turning steps. A high rate of occurrence of printers waste arises thereby, particularly with a small angle of rotation of the ductor roller. It is furthermore disadvantageous that the construction is complicated and a summation of tolerance errors arises due to the multiplicity of hinge points.

Known are also means for the discontinuous drive of a ductor roller for inking mechanisms, in which the drive takes place through a cam coupling gear and the adjustment of the angle of rotation of the ductor through a rotation of the control cam (DL-PS 111 329).

Such means have the same abovementioned disadvantages. It is furthermore disadvantageous that an exact setting of the ink metering is very complicated, since at different speeds of rotation of the ductor roller, brought about through the different angles of rotation of the ductor roller, a different ductor blade deformation arises through the different hydro-dynamic pressure connected therewith.

According to the present invention there is provided a liquid applicator device for a printing machine, comprising a ductor roller, input means, output means connected to the ductor roller, and coupling means so intercoupling the input and output means that uniform motion of the input means causes discontinuous motion of the output means, the input and output means being relatively displaceable to determine the phase relationship between their respective motions.

The drive of the coupling means may be derived from any desired location in the machine, for example from a distributor drive. Continuous rotational motion of the input means is converted by the coupling means intercoupling the input and output means into a non-uniform motion which is transmitted to the ductor roller. The drive of the ductor roller may take place stepwise, i.e. it carries out a rotary motion in one direction, stands still and then carries out the next step in the same direction.

Speed and stepping angle of the ductor roller may remain constant at equal speed of the machine and vary only with a variation of this speed.

A vibrator may likewise be driven in a rigid transmission ratio to the machine, i.e.

its bearing times against the ductor and distributor are dependent only on the machine speed. Thereby, a rigid relationship arises of ductor speed, ductor stepping angle and vibrator bearing time against the ductor, so that a certain quantity of ink is transferred from the ductor to the vibrator.

When this quantity of ink is to be varied, then the phase position of the motions of vibrator and ductor is carried out through an adjustment of the position of input and output means of the non-uniformity gear to one another, so that the instant of the switching step of the ductor varies relative to the bearing of the vibrator against the ductor.

The relationship of vibrator bearing against the ductor in the time of the motion of the ductor serves as starting point so that a maximum ink quantity transfer takes place. When the quantity of ink is to be reduced, then the range of the standstill of the ductor is partially displaced into the range of the bearing of the vibrator against the ductor. In the extreme case, the bearing of the vibrator against the ductor can take place in the time of the standstill of the ductor so that the quantity of ink taken over is practically equal to zero.

A uniformly driven cam may be forcelockingly connected with a rocker, which is adjustable in its position relative to the cam, constructed as toothed segment with cam roller and connected through spur wheel stages with a ductor drive wheel, wherein a freewheel is arranged between the ductor driving wheel and the ductor.

The rocker is rotatably journalled on a web, which is rotationally movable about the axis of the cam and which is connected through transmission elements of toothed displacing segment and pinion with a hand wheel. A roller lever may be arranged on a uniformly driven carrier spur wheel to engage through a follower roller into a displacing cam and may be connected fast with an input segment, which stands in engagement with the ductor driving wheel, wherein the position of roller lever to displacing cam is settable. The displacing cam engages by an external toothing into a setting pinion connected with a setting wheel.

Embodiments of the present invention will now be more particularly described by way of example with reference to the accompanying drawings, in which: Figure 1 shows a schematic illustration of an inking mechanism of a rotary sheet offset printing machine, Figure 2 shows a schematic illustration of a device embodying the invention, Figure 3 shows a side elevation of the device as shown in Figure 2, Figure 4 shows a graphical representation illustrative of the operation of the device shown in Figures 2 and 3, Figure 5 shows a schematic illustration of another example of a device embodying the invention and Figure 6 shows a side elevation of the device shown in Figure 5.

Referring to the accompanying drawings, Figure 1 shows a known arrangement in a printing machine for transferring ink to a printing matrix of the machine.

Ink is stored in an ink store 33. As a result of rotation of an ink ductor roller 18, ink is fed through a gap between the tip of a ductor blade 34 and the peripheral surface of the ductor roller 18. The motion of the ductor roller 18 takes place stepwise in a series of rotational movements each of a predetermined angle of rotation. The ink is then transferred to a distributor roller 22 by way of a pivotably mounted roller 21, which moves to and fro between the ductor 18 and the distributor roller 22 in the manner of a pendulum. The ink is then transferred by way of ink transfer roller 35 and ink applicator rollers 36 to a printing matrix (not shown) which is clamped onto a plate cylinder 37 and from this by way of a not illustrated rubber cylinder to a copy sheet disposed on a not illustrated printing cylinder.

The drive of the ductor roller 18 and of the pendulating roller 21 is synchronised with the operation of the printing machine, i.e. it is controlled in dependence on the speed of the printing machine. The drive of the vibrator roller 21 is not more closely illustrated. The transmission ratio of the motion of the ductor roller 18 and of the vibrator roller 21 is constant.

The Figures 2 and 3 show two views of a device embodying the invention.

Journalled in a frame 1 (Figure 3) is a distributor drive wheel 9 (Figures 2 and 3), which meshes with an intermediate wheel 8 likewise journalled in the frame 1. The intermediate wheel 8 meshes with a spur wheel 14 (Figure 2) in the form of input means, which is arranged to be rotatably movable on a central shaft 10 journalled in the frame 1. Rigidly connected with the spur wheel 14 is a cam 5, which is likewise journalled to be rotationally settable on the central shaft 10. A rocker 3, which is in the form of a toothed segment, is resiliently urged by means of a spring 15 towards the cam 5 so that a roller follower 16 contacts the periphery of the cam. The rocker 3 is journalled on a web support 2 which is arranged to be rotationally movable on the central shaft 10. The spring 15 is also articulated at the web 2.

The rocker 3 meshes with a middle wheel 4 rigidly connected with the central shaft 10.

A toothed segment 6, which meshes with output means in the form of a ductor drive wheel 7, is likewise rigidly connected with the central shaft 10. The ductor drive wheel 7 is connected by way of a freewheel mechanism 17 with the ductor roller 18 which is also journalled in the frame 1.

A toothed displacing segment 19, which meshes with a pinion 11, is connected fast with the web 2. The pinion 11 is rigidly connected with a shaft 12, which is journalled in the frame 1 and with which also a hand wheel 13 is rigidly connected.

The manner of operation is as follows:- The distributor drive wheel 9 is driven by means not more closely illustrated here, for example so as to rotate through half a revolution on each operating cycle of the machine. The distribution itself is not more closely illustrated. The motion of the distributor drive wheel 9 is transmitted by way of the intermediate wheel 8 to the spur wheel 14.

The cam 5 is also driven thereby. The motion takes place uniformly from the distributor drive wheel 9 to the cam 5. The motion of the cam 5 is transmitted by way of the cam roller 16 to the rocker 3, which carries out a pendulum-like motion. The motion of the rocker 3 is dependent on the shape of the cam profile of the cam 5.

The motion of the rocker 3 is transmitted by way of the middle wheel 4 and the central shaft 10 to the toothed segment 6, which drives the ductor drive wheel 7 non-uniformly. Through the freewheel mechanism 17 constructed as wedging roller coupling, this non-uniform motion is transmitted in only one direction to the ductor 18, which thereby carries out a discontinuously rotary motion. As has been described with reference to Figure 1, the pivotably mounted roller 21 carries out a pendulating motion between the ductor roller 18 and a first distributor roller 22.

To obtain a different rate of withdrawal of ink by the pendulating roller 21 from the ductor roller 18, the phase relationship between the motion of the ductor can be varied in relation to pendulum motion of the roller 21.

This variation can also take place during the running of the machine.

The toothed displacing segment 19 is pivoted by means of the hand wheel 13 by way of the pinion 11. Since the toothed displacing segment 19 is rigidly connected with the web 2, this web 2 is thereby simultaneously rotated around the central shaft 10. The rocker 3, which through this rotation is likewise rotated around the central shaft 10, is fastened to cam roller 16, which is thereby moved to another position relative to the profile of the cam 5, so that the phase of the motion of the ductor roller 18 varies in relation to the bearing of the vibrator 21 against the ductor roller 18. Accordingly, the speeds of rotational motion of the ductor roller 18 and of the vibrator roller 21 and the characteristics of the course of motion of the ductor roller 18 are maintained and only their phase position relative to one another is varied.

The course of the motion of the ductor roller 18 and the distributor bearing is illustrated in Figure 4. The extreme case maximum ink transfer -- is illustrated fully drawn, i.e. the distributor bearing against the ductor roller 18 takes place during the rotational motion of the ductor roller 18.

Drawn in dashed lines is another setting, in which the bearing of the roller 21 against the ductor roller 18 takes place only partially in the time of motion of the ductor roller 18, i.e. the quantity of ink transferred is less.

Another example of a device embodying the invention is illustrated in the Figures 5 and 6.

Journalled in a frame 1 is an input spur wheel 23, which receives its drive from the drive of the machine, for example from the distributor drive.

The input spur wheel 23 meshes with a carrier spur wheel 24, which is loosely journalled on a ductor axle limb 25. A roller carrying lever 27, connected fast with an input segment 26, is journalled to be rotationally movable on this carrier spur wheel 24.

The input segment 26 engages with a ductor drive wheel 7, which is connected fast with the ductor roller 18 by way of the ductor axle limb 25. Mounted on the lever 27 is a roller follower 28, which engages a setting pinion 32 connected with a setting wheel 31. The manner ofoperation is as follows: The input spur wheel 23 is rotated through half a turn for each operating cycle of the machine by means not more closely illustrated here. This motion is transmitted to the carrier spur wheel 24, so that also the input segment 26 with its roller lever 27 rotates uniformly. The displacing cam 29 remains stationary.

Through the engagement of the follower roller 28 in the groove of the displacing cam 29, the input segment 26, in addition to its motion through the uniform rotation of the carrier spur wheel 24, receives a component of motion in dependence on the cam shape of the displacing cam 29. The two motions add or subtract so that the ductor roller 18 receives a non-uniform motion. The displacing cam 29 is so constructed that the ductor roller 18 executes a discontinuous, i.e. a stepping motion in always the same direction of rotation.

For the displacement of the phase position of the motion of the ductor roller 18 to the motion of the vibrator roller 21, the setting wheel 31 is rotated. By way of the setting pinion 32, the displacing cam 29 is also rotated thereby, whereby the follower roller 28 is disposed to contact a different part of the displacing cam 29 and the stepping motion of the ductor roller 18 is thereby displaced relative to the motion of the vibrator roller 21. This variation can take place also during the running of the machine.

The invention is not restricted to the two gears, which have been described by way of example, but relates also to such other non-uniformity gears as fall within the scope of the claims. Characteristic of such gears embodying the invention is the possibility of the adjustment of the relative position between a uniformly driven input element and an output element to provide non-uniform output.

It is further characteristic that an adjustment of this relative position during standstill of the machine effects a rotational motion of a ductor roller, such as the roller 18.

Still to be mentioned by way of example are two-wheel gears with dwell, three-wheel gears with dwell and double-crank gears.

Moreover although the invention has been described with particular reference to its application to an inking mechanism of the printing machine it is applicable to other liquid applicator mechanisms such as moistening mechanisms.

WHAT WE CLAIM IS: 1. A liquid applicator device for a printing machine, comprising a ductor roller input means, output means connected to the ductor roller, and coupling means so intercoupling the input and output means that uniform motion of the input means causes discontinuous motion of the output means, the input and output means being relatively displaceable to determine the phase relationship between their respective motions.

2. A device as claimed in claim 1, wherein the output means is fixed and the input means is adjustable.

3. A device as claimed in claim 1, wherein the input means comprises cam means and the output means comprises rocker means comprising a toothed segment provided with a follower roller contacting the cam means, the rocker means being connected by way of a plurality of spur gear elements to a drive gear of the ductor roller.

4. A device as claimed in claim 3, comprising a freewheel mechanism connected between the drive gear and the ductor roller.

5. A device as claimed in either claim 3 or claim 4, wherein the rocker means is rotatably journalled on a web member which is angularly displaceable about the axis of rotation of the cam means and which is connected by way of a further toothed segment and a pinion to manually operable setting means.

6. A device as claimed in either claim 1 or claim 2, wherein the input means comprises a spur gear carrying a pivotably mounted lever member which is provided wit a roller follower contacting cam means, a toothed segment meshing with a driving gear of the ductor roller and connected to the lever member to be pivotably displaceable therewith, the position of the lever member relative to the cam means being settable.

7. A device as claimed in claim 6, wherein the cam means is provided with gear teeth meshing with a pinion which is rotatable by manual setting means.

8. A device as claimed in any one of the preceding claims, comprising setting means selectably operable during operation of the device to adjust the relative position of the input and output means.

9. A liquid applicator device for a printing machine, substantially as hereinbefore described with reference to and as illustrated in Figures 1 to 4 of the accompanying drawings.

10. A liquid applicator device for a printing machine, substantially as hereinbefore described with reference to and as illustrated in Figures 1 and 4 to 6 of the accompanying drawings.

11. A printing machine comprising a device as claimed in any one of the pre

Claims

ceding claims.