JPH04229263A - Device for adjusting axial interval between rubber blanket cylinder and plate cylinder in sheet-feed offset printing machine - Google Patents

Abstract

PURPOSE: To vary the cylinder insertion pressure easily in a short time by improving an apparatus for adjusting the distance between the axes of a blanket cylinder and a plate cylinder in a sheet-feed offset press having one or more printing units. CONSTITUTION: Adjusting members 3 of all printing units are pivotally connected with an adjusting rod 4 which can be adjusted by way of an operating member provided at a paper discharge section 1 such that the distance between the axes of a blanket cylinder G and an impression in all printing units can be varied in same direction.

Description

[Detailed description of the invention]

0001

FIELD OF INDUSTRIAL APPLICATION The invention relates to a device for adjusting the axial spacing between the blanket cylinder and the plate cylinder of a sheet-fed offset printing press, in which one or more printing presses are provided. , in each printing device, the distance between the blanket cylinder, which is supported at both ends by rotatable eccentric bushings, and the impression cylinder is varied by means of an adjusting member (printing pressure adjustment).

0002

BACKGROUND OF THE INVENTION According to Swiss Patent No. 441,382, it is possible to adjust the axial distance of a blanket cylinder supported on both sides of an eccentric bush in a printing unit of an offset printing press to an impression cylinder as desired. pressure regulation) is disclosed. With such an eccentric bearing, it is possible to additionally insert and remove the blanket cylinder in conjunction with the impression cylinder and the plate cylinder. For this purpose, an angle lever transmission formed by two links is provided, which on the one hand acts on the eccentric bushing and on the other hand its support for changing the shaft spacing or the printing pressure. It has an adjustment member. In its extended position (retracted position) the angle lever drive acts like a simple rod and the printing pressure can be varied by means of an adjusting member. In addition to the scale, the adjustment elements today also have adjustment dials on which the axial spacing between the blanket cylinder and the impression cylinder, or the change in this axial spacing, and thus the printing pressure can be read. When the scale on the adjustment dial indicates zero, it means that the rubber cylinder has just come into contact with the surface of the impression cylinder and is not pressed against it.

In known devices of this type,
The printing pressure of each printing device has to be changed individually, which, in a large number of printing devices and in printing machines with a correspondingly long construction, is cumbersome and time-consuming since the work steps for adjusting the printing pressure increase accordingly. The disadvantage is that it becomes expensive. When adjusting the printing press for production printing, the printing operator should judge the printing pressure by the quality of the printed sheets or, from the printing result, adjust the pressure as the case may be in the printing device. Changes in printing pressure must be estimated. If it is desired to uniformly increase or decrease the printing pressure in each printing device, the same work is required in each printing device, resulting in a large loss of time and a large number of printing failures.

0004

SUMMARY OF THE INVENTION It is therefore an object of the present invention to improve a device of the type mentioned at the beginning so that the printing pressure can be changed easily and quickly.

[0005]

According to the device of the present invention which solves this problem, the adjustment members of all printing devices are hingedly connected to a common adjustment rod, and this adjustment rod is connected to a common adjustment rod. The axial distance between the blanket cylinder and the impression cylinder can be adjusted in the same direction by an operating member provided on the sheet discharge section.

[0006]

According to the present invention, the printing pressure can be adjusted in common for all printing apparatuses from the paper discharge section side. In other words, central control can be performed from the paper discharge section side. The printing operator takes out the printed sheets at the paper delivery section, determines whether the printing pressure needs to be changed or not, and immediately changes the printing pressure based on the judgment. This is very advantageous, especially if the sheet type or sheet thickness changes during printing. In this way, the printing pressure can be quickly adjusted to the new sheet thickness. In the same way, before the new sheet to be printed, a predetermined number of previously printed sheets of another type, especially of different thicknesses, are passed through the printing press and printed. Also, when an operator immediately changes the printing pressure after changing a sheet, and at the same time tries to judge the quality of the print from the first print on a sheet of different thickness, apply.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an offset printing press having a plate cylinder P, a blanket cylinder G, an impression cylinder D, and a transfer cylinder T arranged in tandem. The sheets printed by the last printing device are
The sheets are stacked at the paper discharge section 1. As shown schematically, each blanket cylinder G is mounted on two eccentric bushings 2, which can be pivoted in common by an adjusting member 3 in a printing device. This makes it possible to adjust the printing pressure. FIG. 1 is a schematic diagram, and details are explained based on FIG. 2. Each printing device is provided with an adjusting member 3 which pivots the two eccentric bushes 2 to the same extent. This is of the form not shown, in which the adjusting member 3 acts on a shaft which extends over the entire width of the machine and has a lever at each end and a hinged link for pivoting the eccentric bushing 2. This is achieved by being configured as follows. For example, the adjustment member 3 may be a manual (knurled screw)
Alternatively, a tool-operated spindle drive or the like is used.

According to the invention, a central adjustment rod 4 is provided, with which the adjustment member 3 is supported in the printing device. This adjustment rod 4 can be operated from the side of the paper discharge section 1, so that the axial distance between the blanket cylinder G and the impression cylinder D in all printing apparatuses can be changed in the same direction. In this case, the adjustment rod 4
extend inside the machine frame wall and are supported accordingly. As shown in FIG. 1, the adjustment member 3 is provided between each printing device and at a location accessible for operating these printing devices. The adjusting rod 4 extends in particular on the so-called operating side of the offset printing press.

According to one embodiment of the invention, the adjusting rod 4
is supported so as to be movable in the direction in which the adjustment rod 4 extends, and the adjustment rod 4 is controlled via an adjustment dial (screw mechanism with a small inclination) having a scale.
Generally, it is moved by an operating member 5 provided on the paper discharge section 1. When the adjusting rod 4 is moved, the printing pressure of all printing devices can be changed, since the adjusting element 3 is connected downstream of the adjusting rod 4 (tandem connection).

An adjustment member 3 supported by an adjustment rod 4 is provided in each printing device, so that
The printing pressures in the printing device can additionally be adjusted individually, that is to say relative to one another. Therefore, for example, after replacing the blanket cylinder in a printing device, the scale of the actuating member 5 (adjusting dial) of the adjusting rod 4 is reset to zero in the paper delivery section 1 and then in the printing device via the respective adjusting member 3. Rubber cylinder G is impression cylinder D
kiss-print on the surface of
. By actuating the actuating element 5, the printing pressure in all printing devices is then varied by the same amount, depending in particular on the paper thickness.

Instead of the longitudinally displaceably mounted adjusting rod 4, it is also possible to provide an adjusting spindle which has the same effect as the adjusting rod 4. An adjusting element 3 is supported on the adjusting spindle in each case by a spindle nut which is secured to the adjusting spindle so that it does not rotate together with the adjusting spindle.

FIG. 2 shows details of one embodiment of the invention. The device for varying the printing pressure is advantageously integrated in the insertion and removal mechanism.

The rubber cylinder G is supported on eccentric bushings 2 on both sides via pins. The two eccentric bushes 2 have links 6
Hinged, these links 6 are hinged at their ends to respective levers 7, which are attached to a cutout shaft 8. The cutout shaft 8 extends over the entire width of the machine and extends through both frame walls. Each of the above-mentioned and below-mentioned members is arranged on the outside of the frame. In particular, via further levers 9 of the punching shaft 8 on both sides of the machine, the punching shaft 8 and thus both eccentric bushings 2 can be pivoted.

A link 10 of an angle lever transmission formed by links 10, 11 is hingedly connected to the lever 9, and this angle lever transmission is journalled on a lever 12 of a printing pressure adjustment shaft 13. A carcass removal rod 14 is hingedly connected to the link 11, and the carcass removal shaft 14 operates an angle lever transmission of the links 10, 11 for carrying out the carcass insertion and carcass removal. The cutout rod 14 is driven, for example, via a roller lever with a pawl that runs along a control cam. The angle lever shown in FIG. 2 corresponds to the trunk-loading position. The printing pressure adjustment shaft 13 has two levers 15, and the adjustment member 3 is hingedly connected to these two levers 15. As shown, the end of the lever 15 is configured in the shape of a fork. A pin 16 of the adjusting member 3 engages with the fork-shaped portion of the lever 15 .

As described in connection with FIG. 1, the adjustment member 3 is supported on the adjustment rod 4. In the embodiment shown in FIG. 2, the adjusting rod 4 is constructed as a rod that is mounted movably in the insertion direction of the adjusting rod 4. In the embodiment shown in FIG. As can be seen in FIG. 2, the adjustment member 3 comprises a first threaded block 17 fixed to the adjustment rod 4 and a second threaded block 17 which engages the fork-shaped part of the lever 15 via a pin 16. It consists of a block 18 and a threaded spindle 19 that changes the distance between these two threaded blocks 17, 18. In this case, the threaded spindle 19 can be manipulated via a hexagonal edge. Of course, variations of the adjusting member 3 are also possible as long as they have the same effect.

Now, if the position of the adjusting rod 4 does not change (the adjusting rod 4 is supported by an operating member 5 of the paper delivery section 1, for example a spindle with an adjusting dial), the screw hole block 17 and the screw hole The spacing between the bushing block 18 and the bushing 18 can be varied via the threaded spindle 19, so that the pin 16 acts on the lever 15 and accordingly adjusts the cylinder G to the mounting position of the eccentric bushing 2 in a known manner. The lever 9, the angle lever transmission device of the links 10 and 11, and the printing pressure adjustment shaft 1 are connected via the shell removal shaft 8.
The lever 12 of No. 3 is rotated, thereby changing the axial distance between the rubber cylinder G and the impression cylinder D. Similarly, when the adjusting rod 4 is shifted via the adjusting member 3 (by the actuating member 5), the eccentric bushing 2 in all printing devices
is forced to rotate.

As shown in FIG. 2, the threaded bushing 17 is supported by a guide roller R so as to be movable parallel to the adjusting rod 4. As shown in FIG. Similarly, the adjusting rod 4 can be designed and mounted as a movable rod.

Next, the device for changing the distance between the impression cylinder D and the blanket cylinder G according to the present invention has, in addition to the above-mentioned advantages of easy operation, a low construction cost and a simple loading and unloading mechanism. can be uniformly incorporated into

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a tandem offset printing press according to an embodiment of the invention.

FIG. 2 is an enlarged view showing details of a portion of the offset printing press shown in FIG. 1 for adjusting printing pressure.

[Explanation of symbols]

Claims (7)

[Claims] 1. A device for adjusting the axial spacing between the blanket cylinder and the plate cylinder of a sheet-fed offset printing press, in which one or more printing presses are provided, and in each printing press a , in which the blanket cylinder, which is supported at both ends by pivotable eccentric bushings, is arranged such that its spacing relative to the impression cylinder can be varied by means of an adjusting member, the adjusting member (3) of all printing devices is common. It is hinged to an adjusting rod (4), which allows the axial spacing between the blanket cylinder (G) and the impression cylinder (D) to be varied in the same direction in all printing devices. for adjusting the axial spacing between the blanket cylinder and the plate cylinder of a sheet-fed offset printing press, characterized in that it is adjustable by means of an operating member (5) provided in the paper delivery section (1). equipment for. 2. Apparatus according to claim 1, wherein the adjusting rod (4) extends on both sides of the offset printing press and inside the frame wall member. 3. The adjusting rod (4) is configured to be movable in the direction in which the adjusting rod (4) extends, and is controlled by an operating member (5) via a spindle drive fixedly supported on the printing press. 3. Apparatus according to claim 1 or 2, operable by: ). 4. The adjusting rod (4) is configured as a threaded spindle and is provided with a spindle nut fixed against rotation with the threaded spindle, with which the adjusting member ( 3) is supported and hinged. 5. The operating member (5) is constructed as an adjusting dial having a scale, with the adjusting dial being able to read changes in the shaft spacing. The device described. 6. The adjusting element (3) is constructed as a spindle drive, which is arranged between the printing units at a location accessible to the operator from the outside and can be adjusted manually or with a tool. 6. The device according to claim 1, wherein the device is operable. 7. An adjusting member (3) for changing the axial distance between the rubber cylinder (G) and the impression cylinder (D) is attached to one lever (1).
5), the other lever (12) is pivotable via the printing pressure adjustment shaft (13), and the other lever (12)
12) forms a corresponding bearing of an angle lever transmission formed by two links (10, 11), said links (10) forming a recessed shaft (8) extending over the entire width of the machine. is hingedly connected to a lever (9) of the body, said truss shaft (8) having levers (7) at both ends, said lever (7) being connected via a link (6) to a lever (9).
associated with an impression cylinder (D) and a plate cylinder (P), which are hinged to eccentric bushings (2) present on both sides of the blanket cylinder (G) and formed by two links (10, 11); 7. According to one of claims 1 to 6, a shell removal rod (14) is hingedly connected to a link (11) of an angle lever transmission for inserting and removing the blanket cylinder (G). Device.