SU436477A3 - PRINTING DEVICE - Google Patents

Description

one

The invention relates to printing presses.

A printing device comprising a printing cylinder with a squeegee made of ferromagnetic material and a support located under it, consisting of an electromagnet located inside the conveyor and providing the squeegee against the inside surface of the printing cylinder, is known.

During operation of the known device, banding occurs on the material, which occurs due to the violation of pressure uniformity between the material being processed and the working body, as a result of, for example, the deflection of the latter or the support located under it, which leads to a deterioration in print quality.

To improve print quality, the proposed device is equipped with a nozzle installed in the core of the electromagnet and communicating with a source of working medium for feeding it into the space between the support and the conveyor in the area of contact with the printing cylinder.

FIG. 1 shows the proposed printing device, a cross-section along the working body; in fig. 2 - the same, longitudinal section; in fig. 3 is a diagram of a press of another type; in fig. 4 is a sectional printing apparatus shown in FIG. 3, on an enlarged scale.

The strip of material 1 on which printing is performed moves in the direction

Arrows 2 Iodine printing cylinder 3. Inside this cylinder, in the place where it comes into contact with the material, is rac 4, made of ferromagnetic material in the form of a roller rotating on the inner side of the cylinder as the latter rotates in the direction of arrow 5. At the same the stencil on the strip of material paint coming into the printing cylinder through the tube 6. To hold the doctor blade inside the cylinder in a certain place there is a support bar 7. The cylindrical stencil is clamped in the machine with g tin 8 (see fig. 2). As a conveyor for a strip of material rotates in the direction of arrow 9 a thin metal cylinder 10, inside of which there is a fixed support 11 and a hollow space 12, bounded on both sides by a slot 13. After the space is connected via pipeline 14 to the main pipeline 15. Pipe 14 ends with a branch pipe through which pressure air or some working medium is supplied under pressure into space 12, as a result of which a cushion is created between the fixed support AND and the metal cylinder 10, which uniformly and steadily pressing the cylinder 10 and the material on top of it towards the cylinder 3. Excess compressed air or working medium passes through the slots 13, which eliminates friction between the metal surfaces of the cylinder 10 and the support 11.

Electromagnet 16 with core 17 is mounted in support And, the lower end of which is connected to bus 18, and the upper end is located at the bottom of space 12. When electromagnet 16 is switched on, 4 is attracted by this electromagnet and presses cylinder 3 with uniform pressure across the width to the strip material.

A pipe 14 with a nozzle is installed in the core 17 of the electromagnet 16. The continuous flow of working medium into the cavity 12 under pressure prevents the metallic cylinder 10 and the support 11 from contacting.

In a different type of printing press (see Fig. 3), an endless conveyor 19, tensioned between two rollers, one of which is driven, serves to advance the strip of material. Above the upper branch of the conveyor there are several cylindrical stencils. Ink is supplied to the inside of each cylinder 3 through pipe 6. Inside the printing cylinder (see Fig. 4), in the place where it comes into contact with the strip of material, a racter 4 is placed, which rotates as the cylinder 3 rotates in the direction of arrow 5 and squeezes out the inside the cylinder paint 20 through the holes of the stencil on the strip of material.

The device has a support 11 under the conveyor 19 with a coating layer 21 of a high polymer material. In the coating 21 there is in the zone of contact of the cylinder 3 with a strip of material a hollow space 12 and groove grooves 22 in the form of a labyrinth seal.

Inside the casing 23 there is a system of electromagnets consisting of coils of electromagnets 16 and cores 17, which are located across the direction of movement of the strip of material. When electromagnets are turned on, squeegees 4 made of ferromagnetic material are attracted. To secure the electromagnets B to the cover 21, a groove 24 is machined in each core 17, and in the well slot 25 there is an adhesive attachment.

The cores 17 have axial holes 26,

to which the pipelines 14 are connected with nozzles located at the level of the hollow space 12, to which the working medium is supplied under pressure, forming a pressure pad that interacts with the lower side of the conveyor 19 and ensures uniform and constant pressure of the material with the cylinder 3.

The working medium leaves space 12 through slots 27 (see FIG. 4, indicated by arrows). Grooved notches 22 prevent leakage of the working environment 22.

Subject invention

A printing device containing a printing cylinder with a blade of ferromagnetic material and a support located under it, consisting of an electromagnet located inside the conveyor and providing the blade against the inner surface of the printing cylinder, characterized in that in the core of the electromagnet, a nozzle communicating with a source of working medium for supplying it to the space between the support and the conveyor in the area of contact with the printing cylinder.

13

or

.2

FIG. 3