SU854752A1 - Device for forwarding sheets through printing unit of flat-bed press - Google Patents

Description

one

The invention relates to printing production and can be used in flatbed printing machines with different patterns of movement of the printing cylinder.

A device is known for posting a sheet in a printing machine of a flat-bed printing machine, comprising a printed CI.PINDR mounted on a frame, a taler with grippers, a sheet returning cylinder, and a conveyor belt. Both taler strokes, forward and reverse, are working and are used to produce prints. The axis of rotation of the printing cylinder is fixed, the axis of the additional cylinder is periodically making vertical displacements, and this cylinder is permanently connected to the printed cylinder through a parasitic gear and periodically with the toothed rack of the thaler. The outfeed conveyor is connected to the printing cylinder by means of two one-way clutches and gears, informing it of intermittent movement in one direction fl.

This device has inadequate First, wiring a sheet from an adhesive table to a sheet-feed conveyor is carried out by five

various gripping mechanisms. With multi-color printing, such a complex wiring system negatively alters the accuracy of ink matching

5 print. Secondly, after transferring the sheet from the fixed grippers of the thaler to the grippers of additional cypinder (while the sheet is in contact with the surface of the form with the entire surface)

  there is a sharp rise of the latter in order to avoid collision with the thaler and the separation of the print from the form. Such an impact on the print causes a relative shift in its shape,

15 which degrades print quality. Thirdly, after the trailing edge of the sealed sheet leaves the printed reference number, the latter is free, as a result of which

20, the tension of the free part of the sheet and its fixation relative to the shape disappear, which also causes displacement of the print relative to one form, which means that the print quality is hooded. Fourth, the implementation of the drive of a variable speed leaf conveyor through overrunning clutches causes a deterioration in the driving dynamics of the machine and does not ensure the accuracy of the position of the conveyor hooks relative to the grips of the other organs conducting the sheet wiring. This limits performance and impairs machine reliability.

The purpose of the invention is to improve the quality of printing.

The goal is achieved by the fact that the device for posting a sheet in a printing machine of a flat printing machine, comprising a printing cylinder mounted on a bed, a taler with grippers, a leaf-down cylinder and a conveyor belt, has support rods with rollers mounted in talted guide grooves and rigidly mounted on the groove fists, each of which is in contact with the roller of the corresponding rod, while the grippers are pivotally mounted on the supporting rods.

FIG. 1 shows a device for wiring a sheet of printed material in a printing apparatus of a flat-bed printing machine; in fig. 2 - bar with grippers of this device.

A device for wiring a sheet in a printing machine of a flat-bed printing machine contains a printing cylinder 1 mounted on a frame, a thaler with grippers 2, a leaf-down cylinder 3 a conveyor 4, bearing rods 5 with rollers 6 mounted on the sides of the thaler grooves 7. The device contains rigidly mounted on the frame groove fists 8, each of which is in contact with the roller 6 of the corresponding rod 5, the grips 9 and 10 are pivotally mounted on the supporting rods 5.

The device works as follows.

In the extreme right position of the thaler 2, the claws 9 and 10 stop near the inclined table 11 and grab the sheet. When the thaler moves to the left (working stroke), these grippers transport the sheet along the directions of the folding table 11 to the printed contact area. The trajectory of movement of the grippers 9 and 10 is determined by the slotted cams and guides 12, respectively orienting the position of the axis 13.

The rods 15 are located on the sides of the taler 2 and carry on the upper ends the axis 13, on which the clamps 10 and the lever with the roller 14 are fixed. The grippers 10 are closed by a spring 16. To choose the gap between the roller 6 and the wall of the groove cam 8, there is a manual 17.

To control the grippers 9, a slide mechanism 19, driven by a cam 20 mounted on a single-turn shaft, such as a crank 21, is used to move the grips 9, which is used to control the opening and closing of the grippers 9 and 10 near the sheet-water cylinder 3 by means of the lever 23 and 5 of the slide 24.

The orientation of the axis 13 with grippers 10 relative to the guide feathers of the overlay table 11 when removing the sheet from it and relative to the guide

At the withdrawal of the sheet from the printing apparatus, lO 25 is guided by Odanina 12 with which the roller 14 communicates, which is connected by a lever with the axis 13, interacts. When removing the sheet from the printed

15 of contact, the angles of inclination of the groove 8 to the horizontal and the rod 6 to the movement of the taler ensure the ratio of the speeds of the taler and the grippers (Fig. 2), allowing the sheet to be removed without displacing it relative to. After wiring the sheet through the printed contact, the grippers 9 and 10 transfer the sheet to the grippers 26 of the sheet-holding cylinder 3. The linear velocities of the grippers 9 to

2J 10 as well as cylinder 3 are equal. The location of the receiving cylinder relative to the printing cylinder and the discharge conveyor 4 ensures the transfer of the sheet to the grippers of this

tn after. exit sheet of

 print contact.

Since the sheet-leading cylinder 3 is driven either through the printing cylinder 1 or directly from the tag 2. The transfer of the sheet to the discharge transport 4 can be carried out at a low speed equal to the speed Tssher at a certain part of its movement near the end position.

0 As a consequence, the output of the sheet from the car by the conveyor 4 also occurs at low speed, which ensures the drying of paint on prints when they are removed, and also disappears when

45 this is the need for a sheet of slow devices.

To reliably prevent the sheet from moving relative to the surface of the mold, it is necessary that

(JQ friction of the sheet on the elastic surface of the printing roller was very easy, which can be achieved, for example, by selecting the appropriate material for the elastic tire, and

- also that the linear speed of this tire in the center of the printed contact is less than the speed of the thaler.

Due to the fact that the sheet is wired in a printed contact by rigid devices located on the taller or associated with them kinematically, the slip of the sheet relative to the surface of the form located on the taller is eliminated, which improves printing accuracy and reduces the wear of the form.

Claims (1)

Claim A device for posting a sheet in a printing apparatus of a flat-printing machine, comprising a printing cylinder mounted on a bed, a tacker with seals, a sheet-output cylinder and a conveyor, characterized in that, in order to improve print quality, it has support rods with rollers installed in guides made in the thaler grooves, and grooved fists rigidly mounted on the frame, each of which is in contact with the roller of the corresponding rod, while the grippers are pivotally mounted on the bearing rods.