GB1565766A

GB1565766A - Printing machine

Info

Publication number: GB1565766A
Application number: GB935378A
Authority: GB
Original assignee: Polygraph Leipzig Kombinat Veb
Current assignee: Polygraph Leipzig Kombinat Veb
Priority date: 1977-03-11
Filing date: 1978-03-09
Publication date: 1980-04-23
Also published as: FR2383017B1; DD132253A1; FR2383017A1; DE2808856A1; DE2808856C2; SU943013A1

Description

(54) PRINTING MACHINE (71) We, VEB POLYGRAPH LEIPZIG KOMBINAT FijR, POLYGRAPHISCHE MASCHINEN UND AUSRijSTUNGEN of 705 Leipzig, Zweinaundorfer Strasse 59, 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 printing apparatus.

In known printing apparatus comprising vibrator inking mechanisms, a vibrator roller bears briefly against a slowly rotating ink pick-up roller and then against a first ink transfer roller rotating with the speed of printing. The vibrator roller, which is not driven on its own, is entrained by the ink pick-up roller during the transfer of a more or less narrow ink stripe by friction. After the movement stroke, the vibrator roller bears against the first ink transfer roller. In this instant, the energy requirement for the instantaneous acceleration of the vibrator roller has the effect of a shock which leads to a series of unpleasant phenomena reducing the quality of printing.

Measures, such as those disclosed in the US-PS 3 002 451, according to which the drive connection between the printing cylinders and the rollers of inking mechanism takes place relatively elastically by way of roller chains or the like. merely provide a certain damping of the above mentioned drive shock.

To avoid the shock as far as possible, an inking mechanism has become known through the disclosure of DT-OS 2 031 504, in which a motor is provided for acceleration of the vibrator roller. The vibrator roller is accelerated during the movement stroke by a special driving roller disposed in frictional connection with it so far that the shock loading arising at the instant of the contact of the first ink transfer roller is brought to a minimum in the inking mechanism.

Disadvantages of the disclosure of DT-OS 2 031 054 are the high technical expenditure and that the driving roller associated with the vibrator roller lies outside the ink flow and so acts as an undesired ink storage. Thereby. the inking mechanism becomes sluggish for necessary corrections of inking quantities and inking profiles. i.e. variations of setting at the ductor blade etc. become effective on the printed product only after a considerable time.

To remedy this defect, US-PS 3 688 696 discloses a motor, which drives the vibrator roller through two V-belts, and which is switched on when the vibrator roller lifts off from the duct roller. The speed of the motor is so controlled during the stroke motion of the vibrator roller that the vibrator roller has a relatively high peripheral speed before it touches the first ink transfer roller. Associated with the motor is a tachometer which switches off the motor on the attainment of a predetermined rotational speed. Likewise the high technical expenditure is disadvantageous. With normal running speeds of modern rotary printing machines, a working cycle at the vibrator lasts only about 0.5 seconds. The acceleration phase, thus the time of the vibrator motion between the ink pick-up roller and the first ink transfer roller, lies in the region of tenths of a second. From this, a high loading. above all of the motor, may occur and therefore a high fault liability.

A printing machine comprising an ink pick-up roller for picking up ink from a supply thereof, an ink transfer roller spaced from the ink pick-up roller. a vibrator roller displaceable between the ink pick-uproller and the ink transfer roller to transfer ink from the ink pick-up roller to the ink transfer roller. and an ink distributor roller drivable from a main drive shaft and operably connected to the ink transfer roller by a further roller rotatable by friction between its peripheral surface and respectively the peripheral surface of the ink transfer roller and the peripheral surface of distributor roller, wherein the ink transfer roller is drivably connected to the main drive shaft independently of the drive connection to the distributor roller.

At least the peripheral surface of the further roller may be provided by a layer comprising rubber.

The printing machine may further comprise a cam to displace the vibrator roller between the ink pick-up roller and the ink transfer roller. the cam being drivably connected to the main drive shaft independently of the drive connection to the distributor roller.

The ink pick-up roller may be drivably connected to the main drive shaft independently of the drive connection to the distributor roller.

The cam and the ink transfer roller may be drivably connected by common transmission means to the main drive shaft.

The ink pick-up roller and the ink transfer roller may be drivably connected by common transmission means to the main drive shaft.

An embodiment of the present invention will now be more particularly described by way of example and with reference to the accompanying drawings in which: Figure I shows a schematic illustration of a part of the upper half of a first form and inner form printing mechanism of a rotary roller offset printing machine, Figure 2 shows a schematic illustration of the drive of the mechanism shown in Figure 1, and Figure 3 shows a side elevation of the drive shown in Figure 2.

Referring now to the accompanying drawings, rubber blanket cylinders 3 and 4 are arranged above and below a web 2 and their respective plate cylinders 5 and 6 are arranged between the walls of the machine frame 1. An inking mechanism is associated with each of the plate cylinders 5 and 6. The ink held by an ink wall 7 is transferred by an ink pick-up roller 8 stripe by stripe to a vibrator roller 11 which is moved to and fro by means of a cam 9 and a cam roller 10 and from which the ink is transferred to a first ink transfer roller 12 and then by way of a first rubber roller 13. distributor rollers 14. further rubber rollers 13 and applicator rollers 15 to printing plates of the plate cylinders 5 and 6.

Figure 2 shows the driving wheel trains for the various rollers. Only those rollers up to the uppermost distributor roller 14 are driven from the main drive shaft 16 by way of the rubber blanket cylinder driving gear wheels 4' and 3', the plate cylinder driving gear wheels 5' and 6' and the distributor roller driving gear wheels 14'.

The first ink transfer roller 12 and the cam 9 are driven through driving gear wheels 12' and 9' and shaft 17 independently of the rollers 3 and 4. 5 and 6, and 14 from the main drive shaft 16.

In place of the translation gears of cone and spurwheels. the separate drive may take place by way of chain drives or toothed belts.

In place of a motor 18 in the dirvie of the ink pick-up roller 8, the ink roller may also be driven independently of the rollers 3 and 4. 5 and 6. and 14 by driving gear wheel 8' connected for example with the cam driving gear wheel 9'.

Advantages of the embodiment described by way of example above are that the high expenditure for the attainment of the extremely brief high acceleration of the vibrator roller during the vibratory motion is avoided. that the increase in turning moment conducted away into the main drive shaft by reason of the relationships of its size to the stiffness of the drive shaft can lead to no disturbances influencing the quality of printing and that the turning moment shock is so greatly reduced by the arising slip and the elasticity of the transmitting rubber roller that no excitations of oscillation any longer arise in the further inking mechanism and thereby also in the printing cylinders.

WHAT WE CLAIM IS: 1. A printing machine comprising an ink pick-up roller for picking up ink from a supply thereof, an ink transfer roller spaced from the ink pick-up roller. a vibrator roller displaceable between the ink pick-up roller and the ink transfer roller to transfer ink from the ink pick-up roller to the ink transfer roller and an ink distributor roller drivable from a main drive shaft and operably connected to the ink transfer roller by a further roller rotatable by friction between its peripheral surface and respectively the peripheral surface of the ink transfer roller and the peripheral surface of distributor roller, wherein the ink transfer roller is drivably connected to the main drive shaft independently of the drive connection to the distributor roller.

2. A printing machine as claimed in claim 1. wherein at least the peripheral surface of the further roller is provided by a layer comprising rubber.

3. A printing machine as claimed in either claim 1 or claim 2, further comprising a cam to displace the vibrator roller between the ink pick-up roller and the ink transfer roller, the

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. main drive shaft and operably connected to the ink transfer roller by a further roller rotatable by friction between its peripheral surface and respectively the peripheral surface of the ink transfer roller and the peripheral surface of distributor roller, wherein the ink transfer roller is drivably connected to the main drive shaft independently of the drive connection to the distributor roller. At least the peripheral surface of the further roller may be provided by a layer comprising rubber. The printing machine may further comprise a cam to displace the vibrator roller between the ink pick-up roller and the ink transfer roller. the cam being drivably connected to the main drive shaft independently of the drive connection to the distributor roller. The ink pick-up roller may be drivably connected to the main drive shaft independently of the drive connection to the distributor roller. The cam and the ink transfer roller may be drivably connected by common transmission means to the main drive shaft. The ink pick-up roller and the ink transfer roller may be drivably connected by common transmission means to the main drive shaft. An embodiment of the present invention will now be more particularly described by way of example and with reference to the accompanying drawings in which: Figure I shows a schematic illustration of a part of the upper half of a first form and inner form printing mechanism of a rotary roller offset printing machine, Figure 2 shows a schematic illustration of the drive of the mechanism shown in Figure 1, and Figure 3 shows a side elevation of the drive shown in Figure 2. Referring now to the accompanying drawings, rubber blanket cylinders 3 and 4 are arranged above and below a web 2 and their respective plate cylinders 5 and 6 are arranged between the walls of the machine frame 1. An inking mechanism is associated with each of the plate cylinders 5 and 6. The ink held by an ink wall 7 is transferred by an ink pick-up roller 8 stripe by stripe to a vibrator roller 11 which is moved to and fro by means of a cam 9 and a cam roller 10 and from which the ink is transferred to a first ink transfer roller 12 and then by way of a first rubber roller 13. distributor rollers 14. further rubber rollers 13 and applicator rollers 15 to printing plates of the plate cylinders 5 and 6. Figure 2 shows the driving wheel trains for the various rollers. Only those rollers up to the uppermost distributor roller 14 are driven from the main drive shaft 16 by way of the rubber blanket cylinder driving gear wheels 4' and 3', the plate cylinder driving gear wheels 5' and 6' and the distributor roller driving gear wheels 14'. The first ink transfer roller 12 and the cam 9 are driven through driving gear wheels 12' and 9' and shaft 17 independently of the rollers 3 and 4. 5 and 6, and 14 from the main drive shaft 16. In place of the translation gears of cone and spurwheels. the separate drive may take place by way of chain drives or toothed belts. In place of a motor 18 in the dirvie of the ink pick-up roller 8, the ink roller may also be driven independently of the rollers 3 and 4. 5 and 6. and 14 by driving gear wheel 8' connected for example with the cam driving gear wheel 9'. Advantages of the embodiment described by way of example above are that the high expenditure for the attainment of the extremely brief high acceleration of the vibrator roller during the vibratory motion is avoided. that the increase in turning moment conducted away into the main drive shaft by reason of the relationships of its size to the stiffness of the drive shaft can lead to no disturbances influencing the quality of printing and that the turning moment shock is so greatly reduced by the arising slip and the elasticity of the transmitting rubber roller that no excitations of oscillation any longer arise in the further inking mechanism and thereby also in the printing cylinders. WHAT WE CLAIM IS:

1. A printing machine comprising an ink pick-up roller for picking up ink from a supply thereof, an ink transfer roller spaced from the ink pick-up roller. a vibrator roller displaceable between the ink pick-up roller and the ink transfer roller to transfer ink from the ink pick-up roller to the ink transfer roller and an ink distributor roller drivable from a main drive shaft and operably connected to the ink transfer roller by a further roller rotatable by friction between its peripheral surface and respectively the peripheral surface of the ink transfer roller and the peripheral surface of distributor roller, wherein the ink transfer roller is drivably connected to the main drive shaft independently of the drive connection to the distributor roller.

cam being drivably connected to the main drive shaft independently of the drive connection to the distributor roller.

4. A printing machine as claimed in any one of the preceding claims, wherein the ink pick-up roller is drivably connected to the main drive shaft independently of the drive connection to the distrbutor roller.

5. A printing machine as claimed in either claim 3 or claim 4, wherein the cam and the ink transfer roller are drivably connected by common transmission means to the main drive shaft.

6. A printing machine as claimed in either claim 4 or claim 5, wherein the ink pick-up roller and the ink transfer roller are drivably connected by common transmission means to the main drive shaft.

7. A printing machine substantially as hereinbefore described with reference to the accompanying drawings.