SU1384221A3 - Device for automatic tension of film - Google Patents

Abstract

The invention relates to an electronic reproduction technique and allows to improve the quality of film tension and to increase the reliability of the device operation. The film 5 coming from the cassette 3 on the suction plate 1 is smoothed by the shutters 17 and 18 and picked up by a pair of rollers 11. The edges of the film 5 are pressed by the slats 19 and 20 moving as the width of the film fixed by the measuring device is changed. The shutters 17, 18 are formed by a cloth wound on the rollers 13 and 14. The rotation of the roller 14 carried out by the engine 21 is transmitted to the roller 13 through a crossed gear belt 22. To tension the film, the pair of rollers 11 rotates faster than the pair of rollers 7. To prevent damage films 5 driven roller of a pair of rollers 11 are covered with a soft antistatic cloth. The exact positioning of the film 5 is provided by the register holes 25 punched on the punch 24 of the punching device. 8 hp f-ly, 3 ill. § SU) with

Description

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The invention relates to an electronic reproduction technique, in particular to devices for tensioning a film when exposed.

The aim of the invention is to improve the quality of the film tension and increase the reliability of operation by eliminating wrinkling of the film and its accurate positioning.

Figure 1 shows a perspective view of a device for automatically tensioning a film; Fig. 2 shows a guide element, a general view; Fig. 3 is a perspective view of another embodiment of the device for automatically tensioning the film.

The device for automatically tensioning the film contains a suction plate 1, in which a row of holes 2 are made. At one end of the suction plate 1, a cartridge 3 is installed, comprising a light-tight housing (not labeled) in which the coil 4 is wound with film 5. From the motor 6, the coil 4 and / a pair of rollers 7, the receiving film 5 in the cassette 3, rotate. The motor 8: serves to rotate the coil 4 and the pair of rollers 7 in the opposite direction.

A pair of rollers 9 located inside the cassette 3 between the pair of rollers 6 and the end face 10 of the suction plate 1 serves as B: as an additional light barrier for the cassette 3 and an additional guide for the film 5 ..

On the other end (not shown) of the suction plate 1, there is another pair of rollers 1, which is driven from the engine 8 through a gear belt transmission 2. The transmission coefficient between the pair of rollers 11 and the pair of rollers 7 is chosen so that the pair of rollers 11 rotates faster, than a pair of rollers 7, to ensure the tension of the film 5.

The pressing force between the rollers of the pair of rollers M is not so large compared with the pressing force between the rollers in the pair of rollers 7. Therefore, friction may occur. One of the rollers, in a pair of rollers 11, may be cloth or may be covered with a soft cloth (not shown) in order not to damage the film 5. In this case,

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Along the side edges of the suction plate 1, two rollers 13 and 14 pass along its entire length, each of which is wound with fabric 15 and 16 respectively (or foil). The width of fabric 15 or 16 corresponds to the length of rollers 13 or I4 or the length of suction plate 1. The lengths of the fabrics 15 and 16 are chosen such that, when they unwind, they completely close the suction plate 1, thus this structure acts as two curtains 17 and 18, respectively. At the ends (not marked) of fabrics 15 and 16, two strips 19 and 20, respectively, are reinforced, which serve as constraints on their movement. Under the action of the weight of these strips 19 and 20, the film 5 is better superimposed on the suction plate 1.

One of the rollers 13 or 14 is driven by the engine 21. The other roller 13 or 14, respectively, rotates due to the transmission of rotation through the crossed toothed belt 22. Both strips 19 and 20 are held opposite each other by means of springs 23 and can be diverted by the action of the engine 21. In order in this case, the strips I9 and 20 again do not come together to each other by springs 3, the engine 21 operates with self-braking or has a brake mechanism (not shown).

The device for automatically tensioning the film operates as follows.

. The film 5 is applied to the suction plate 1 through a pair of rollers 7 and 9. At this time, the strips 19 and 20 are in contact.

As the film 5 is unwound, it acquires curvature and without curtains 17 and 18 would have a bulge upward and therefore would not adhere to the suction plate 1, but since the curtains 17 and I8 are inserted under the closed curtains 17, the material is smoothed over the other end of the suction plate 1 is picked up by a pair of rollers 11. After the film 5 enters the pair of rollers 1, a perforating device (not shown) starts to operate, containing a punch 24, which pierces the register holes 25 on the film 5. The positioning of the film 5, as well as its accurate register fixation, is guaranteed during further processing.

Behind the pairs of rollers 7 and 9 on the front side of the suction plate 1 there is a measuring device 26, with the help of which the width of the film 5 from the cassette 3 is recognized. Depending on this value, in accordance with the movement of the film 5 and the action of the punch 24, the engine 21 operates, and the shutters 17 and 18 are stretched until the strips 19 and 20 are directly on the edges of the film 5. As a result, the film 5 along the edges m is pressed, and its bulge formed after unwinding is eliminated.

. In other words, the holes 2 of the pressure plate f are on the side of the film 5, which; in the absence of curtains 17 and 18, they would have to remain open, in this case they would close, as a result of which full power might develop for the suction of the film 5.

The measuring device 26 has three light channels 27-29, which are closed depending on the width of the film 5.

Suction holes 2 are provided in the suction plate 1. With the help of the spring 30, the strips 19 and 20 are attached to the cable car 31.

At the ends of the strips 19 and 20 and in the corners of the suction plate 1, two pivotally connected metal elements 32, 33 and 34, 35, respectively, can be installed, forming scissors 36 and 37, in which every two ends (not marked) of these elements converge in one common centers of rotation 38 and 39, respectively. The free ends (not indicated) of the elements 32, 33 and 34, 35 can also be rotated, namely the elements 32 and 34 to the corners of the suction plate 1, and the elements 33 and 35 to, the bars 19 and 20. If the bars 19 and 20 move apart , then the centers 38 and 39 of rotation are shifted towards the cassette 2.

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Claims (9)

The claims of the invention are that the drive po1. Device for automatically stretching the film coming from the cas sets on the suction plate containing the first pair of rollers, receiving a film in the cassette and moving it onto the suction plate, a second pair of rollers located between the first pair of rollers and the suction plate, and a roller located on the other end of the suction plate receiving from the suction plate film and transporting it further, and a guiding element, characterized in that, in order to improve the quality of film tension and increase reliability in operation, it is equipped with a driven roller forming the third A roller with a roller located at the other end of the suction plates, mounted rotatably at a higher speed than the first pair of rollers, and the guide element is designed as rollers arranged along the entire length of the suction plate, each of which is wound with a fabric forming a blind, the half-closing suction plate, while at the ends of fabrics that are installed with the possibility of contact, the strips under the action of the tension spring are reinforced, and the rollers are driven, counteracted yuschim spring force stretching. 2. The device according to claim 1, about the tl and is that it is equipped with a measuring device measuring the width of the film and connected with the drive of the rollers. 3. The device according to claim 1, about tl and the fact that at one end of the suction plate, where the third pair of rollers is located, is installed a punching device for piercing in the film of the register holes, the punch of which is located in the hole during exposure. 4. The device according to claims 1-3, which is based on the fact that the roller of the third pair of rollers is made in the form of a velvet brush. 5. The device according to claim 4, characterized in that the surface of the driven roller is antistatic. 6. The device according to paragraphs., That is, the fact that the drive of the rollers is made with self-braking. 7. The device according to claims 1 to 3, about the fact that the first two pairs of rollers are located inside the cassette before leaving the film. 8. The device, according to claim 1, is about tl and is the fact that at the end of each fabric, from the end edge of the suction plate, there are two pivotally connected metal elements made in the form of scissors lying flat on the fabric, one of which is connected to the corresponding the end of one of the planks, and the other, with its free end, is hingedly connected with thirty Yu l the corresponding angle of the suction plate. 9. The device according to claim 8, characterized in that a groove for a punching device is provided on one metal element. A priority п у н к т and m 21.02,84 on PP. 1-5 pp. 6, 8 and 9. by and 7; 11/10/84 18 P