KR100334476B1 - Positioning device of a flexible printing plate on a plate cylinder - Google Patents

Abstract

A groove in which the positioning device of the flexible printing plate of the plate 3 allows the printing plate to be deflected in the rotary press, and the plate 3 having the rotational axis 2 is located in a direction parallel to the rotational axis 2 ( 1), wherein the positioning device of the printing plate is disposed inside the groove. This device is operated by the lateral movement of the plate 3, and this lateral movement starts by the external means and the cam ring 14 arranged outside of the plate facing this means. This means fastened to the frame of the printing press consists of a motor and a mechanism that allows the conventional lateral movement of the plate 3 along its axis of rotation 2. On the inner edges 12, 13 of the cam ring 14 by means of screws 62 and fasteners 60 a roller fastened to a movable base plate held freely about the plate 3 by the retaining means 102. . Two cams 17 firmly attached on the bottom of the groove 1 of the plate 3 control the two rollers 15 attached to the base plate in the reverse tilting motion.

Description

Positioning device for flexible printing plate on plate {POSITIONING DEVICE OF A FLEXIBLE PRINTING PRINTING PLATE ON A PLATE CYLINDER}

The present invention relates to a positioning device of a flexible printing plate on a plate cylinder, in particular an apparatus capable of deflecting such a flexible printing plate on a plate cylinder of a rotary press.

Frequently used in the packaging industry to print plate-like workpieces, such as sheets of paper or cardboard, this type of printing machine is commonly called a flexographic printing press, and is a driving direction of a plurality of constituent stations, namely plate-like workpieces. An infeed station that continuously grabs and feeds a series one after the other from the top of the pile in order from upstream to downstream, for one or more print groups with one or more dryers positioned therebetween, and It consists of the last conveying station for collecting the work. The sheet is conveyed from one station or group to another station or group located above them by a roller train and a suction system, so that the printing surface of the lower surface of the sheet is completely free.

The positioning device of the printing plate is used in the printing group. In general, each printing group that prints one color has a barrel, in which a flexible printing plate is wound around and stretched. These printing plates, covered with ink by the screened pans, print one or more patterns per rotation of the pans on the sheet traveling between the pans and the pressure rollers, depending on the number of printing forms the printing plate has, The plate and pressure rollers are arranged to print the lower printing surface of the sheet.

A printing engraver made of rubber or plastic material is usually bonded onto a flexible support base made of polyester, such as Mylar, to form an assembly called a printing plate. It is precise work to adhere the print typesetting to the polyester base after the production of the print typesetting. The adhesion of the printing typesetting performed by the manufacturer directly influences the quality of the printing register between the various colors. At the upstream and downstream ends of these flexible support bases, plastic strips with longitudinal edges of the U-shaped portions are provided to fix the printing plate to the claws mounted on the plate. This claw is arranged in a direction parallel to the axis of rotation of the plate. The thin metal plate with elongated holes attached to the strip and having a longitudinal upstream-downstream axis allows for quick and accurate positioning of the printing plate on its own plate by a centering pin fixed to the claw.

When adhering the print typesetting on a flexible support polyester base, the transverse or longitudinal positioning errors can be easily corrected by transversely or rotating about the axis of the plate, but errors due to the deflection of the print typesetting If is not so. In this case, since the side of the printing typesetting is not oriented parallel or perpendicular to the upstream and downstream edges of the polyester base, the resultant printing typesetting is deflected to an uncorrectable position with respect to the direction defined by the rotation axis of the platen. .

If multiple print typesettings are glued onto the flexible polyester base with the same deflection error, a single large formation affected by the positioning error due to deflected positioning is generally aligned because the top edge of each print typesetting is aligned. It can be like a printing typesetting.

In order to solve this problem, various conventional apparatuses rotate the front and rear claws about the axis of rotation of the plate to deflect the printing plate by the same amount in the opposite direction to the error.

To this end, U. S. Patent No. 5,488, 904 introduces a device with two parallel bars clamping both ends of a printing plate. The mechanism, controlled by manual rotation of the calibrated eccentric gauge, imparts lateral movement (movement in a direction parallel to the rotation axis of the plate) to the rear fixed bar of the printing plate, and centers around a number of pivots arranged at the ends The assembly of the articulated bending parts allows for pivotal movement of the front bar. Due to the joints actuated by the spring located at one end of the rear bar, when the printing plate is held by the two ends in the device, the rear bar is automatically pivoted in a position parallel to the position occupied by the front bar. Done. The entire mechanism is disposed in the plate body at the bottom of the wide and deep grooves machined in a direction parallel to the axis of rotation of the plate. Eccentric control means of the mechanism is mounted on one side of the plate.

EP 232,730 introduces another deflection device of a printing plate, which proposes a mechanism based on the pivoting of two tension bars with fixed ends of the printing plate. The ends of the tension bar are interconnected by two triangular articulated plates mounted on two stationary pivots fixed to the barrel. The pivot of the joint portion is rectangular, so that the tension bar of the printing plate pivots about an imaginary point P located on the center axis of the plate. The control means is arranged on one side of the plate, which control mechanism consists of a complex mechanism consisting of an articulated lever that can be actuated by a single-acting cylinder when the plate stops at a predetermined position.

Japanese Patent No. 62-56146 solves the problem of deflection of a printing plate by using an apparatus having two bars each operated by two hydraulic cylinders. When the position of the printing plate is to be corrected in the diagonal direction, the hydraulic pressure of the four hydraulic cylinders can be reduced to relax the four springs compressed by the four hydraulic cylinders and press the fixing bar of the printing plate in the opening operation. The correction value is input to the controller, which converts the correction value into a corresponding hydraulic pressure applied to two further hydraulic cylinders arranged on the same side at one end of the fixed bar. Under the action of these two different hydraulic cylinders, the two inclined planes independently linearly pressurize one end of each bar in a vertical motion due to the triangular shape of the inclined plane upon closing of the fixed bar of the printing plate. In a preferred embodiment, the inclined plane may be operated by a motorized screw mechanism.

These devices have the following drawbacks.

There is a so-called closure mechanism, which is bulky and requires a groove in the plate body having dimensions quite large relative to the diameter of the plate,

Due to the arrangement of these mechanisms, there is an undesirable imbalance that creates constraints attributable to the bearing of the plate when the plate reaches a certain rotational speed,

The circumferential working surface around the plate is reduced by the significantly larger width of the grooves required by the deflector,

In some cases a manual adjustment is made, which requires a stop of the press with a long adjustment time,

When resuming a previous operation, the adjustment of the printing plate cannot be relied upon for full automation and for this operation, the adjustments must be stored numerically and remembered, and

In the case of non-manual adjustment, there is a disadvantage in that the mechanism for deflecting the printing plate must be controlled using an additional actuator separate from the actuator which enables the transverse or circumferential movement of the plate.

The deflection device of the printing plate according to the present invention compensates for these drawbacks by providing a simple automation means, which means that it occupies only a minimum of space in the plate body, thereby eliminating the need to stop the printing press. Advantageously, the deflection device does not rely on the deflection mechanism of the printing plate operated by the actuator disposed in the plate body, since it occupies only the minimum occupying volume. Therefore, in order to drive the deflection mechanism of the printing plate, the apparatus of the present invention uses the same electric motor as the motor fixed to the frame of the printing machine and adjusting the transverse movement of the plate. This solution, on the one hand, makes more rational use of pre-provided actuators for lateral adjustment of the printing plate, and on the other hand, is inexpensive and compact, yet robust and reliable, and easily adaptable to sheet metal without the above mechanism. It is possible to obtain a deflection mechanism. Finally, by this mechanism, the use of an external electronic controller connected to a plurality of position sensors arranged outside of the plate can measure and memorize various adjustment positions suitable for each operation, thus eliminating the need for a register. Can be easily resumed. This variant provides additional advantages that are particularly suitable for the mechanism of the present invention.

For this purpose, the present invention provides a positioning device for a flexible printing plate as described in claim 1.

Defining the terminology used in the specification of the present invention to describe the location of some of the components inside the printing press, 'operator's side (CC)' and 'operator opposite side (COC)' are defined by the longitudinal center axis of the printing press. Refer to this side. This is to avoid confusion because conventional terms such as left and right sides change according to the observer's point of view. Likewise, in order to describe the direction of any axis or means, the conventional terms 'length direction' and 'lateral direction' are used, but they are conventionally used with respect to the central axis of the printing press, the direction of which is defined by the traveling direction of the plate-like workpiece. All. Finally, the terms 'upstream' and 'downstream' relate to the direction of travel of the plate-like workpiece in the printing press.

1A and 1B are plan views showing 1/3 of C.O.C and 1/3 of C.C, respectively, of a deflection apparatus mounted on a plate;

2 is a partial cross-sectional view of the C.C end of the positioning device of the flexible printing plate on the plate.

3 and 4 are cross-sectional views of the deflector mounted on the plate, taken along lines A-A and B-B of FIGS. 1A and 1B, respectively.

5A and 5B are plan views showing 1/2 of C.O.C and 1/2 of C.C and a claw support mounted thereto, respectively, of the base plate;

6 is a partial cross-sectional view of the plate in the vicinity of the C.C cam in a direction parallel to the rotation axis of the plate.

7 is a plan view of a C.C cam and a corresponding reinforcement;

8A is a schematic plan view of a deflecting device of a printing plate, in particular showing a state in which the deflecting device is in an intermediate position without deflecting the printing plate;

FIG. 8B is different from FIG. 8A in that the deflector of the printing plate acts in the first end position after rotating clockwise;

FIG. 8C is different from FIG. 8B in that the deflector of the printing plate acts in the second end position after rotating counterclockwise;

* Description of the components of the main parts of the drawings *

1: groove 2: rotation axis

3: plate 4: base plate

5: front claw 6: rear claw

14: Camring 15, 16: Roller

17, 18: cam 25: claw support

26: hole 27: stud

28: screw 63: hole

64: bushing 65: shell

66: compression spring 67, 68: washer

72, 73, 76: hole 80: base

81: pin 62, 82: screw

84: protrusion 102: holding means

103: fixing means

1A and 1B are plan views of a positioning device of a printing plate arranged in a groove 1 machined in a direction parallel to the rotational axis 2 of the plate 3. As well shown in the corresponding cross-sectional views of FIGS. 3 and 4, the deflector is supported on a base plate 4 to which a floating front claw 5 is attached, which front claw 5 is in the notch 7. The front edge of the printing plate 19 arranged around the plate 3 is gripped. The movable rear claw 6, which faces the front claw 5 and grips the rear edge of the printing plate 19 at the notch 8, has a slide 9 at its COC end, which slide 9 Is engaged with the roller 10 which is screwed to the block 100, and this block 100 is fixed to the plate 3 by two fixing screws. At the opposite end of the positioning device (FIG. 2), the base plate 4 is attached to the roller 11, which roller 11 is mounted on a circular cam-ring mounted on a printing machine frame (not shown); 14 is located between the sides 12, 13. As shown in FIGS. 1A and 1B, two different rollers 15, 16 are fixed to the base plate 4 and two cams firmly attached to the bottom of the groove 1 of the plate 3. 17, 18) slide each other. The means 101 comprising an electric motor is mechanically coupled to the plate 3 and can also move the plate 3 in the transverse direction along the axis of rotation 2.

As shown in FIGS. 1A, 1B and 3, the base plate 4 is first fixed by screws 23 on the base plate, and a plurality of rectangular blocks in the form of retained on the base plate by screws 21. And a front claw 5 held by a supporting portion 20, a longitudinally guard plate 22, and a screw 24 that also secures the barrier plate 22. Opposite of the front claw 5, the rear claw 6 is fastened to the claw support 25 of the metal plate having a plurality of elongated holes 26 (Figs. 5A, 5B) (Fig. 4). A stud 27 is attached through the elongated hole 26, which is attached by means of a screw and holds the rear claw 6 over the claw support 25 by means of a set screw 28. By the orientation of this elongate hole 26, the claw support 25 can move laterally with respect to the rear claw 6 and the rear claw 6 is perpendicular to the longitudinal axis of the plate axis of rotation 2. Can be moved. Opening and closing of the rear claw 6 is made by this movement which can tighten or release the printing plate of the plate 3. The claw support 25 is firmly mounted with a screw 29 on two hexagonal blocks 30 which can slide along two axes 31. Both ends of the shaft 31 are respectively supported by the support portions 32 attached to the base plate 4 by screws 33. On each support there is a set screw 34 to fix the shaft 31 in the support 32. Therefore, due to the elongated hole 26, driving the rear claw 6 allows the claw support 25 to move longitudinally along the shaft 31.

The longitudinal opening movement of the rear claw 6 is controlled by seven hydraulic cylinders 40 operating simultaneously (FIGS. 5A, 5B) and the duct held by the clamping plate 42 on the base plate 4. The supply to the hydraulic cylinder 40 is made by 41, and these hydraulic cylinders 40 are mutually attributed by the connecting portion 43. These hydraulic cylinders 40 are mounted on the L-shaped support 44 by screws 45, which also serve as fixing points for the protective plate 22 and the front claw 7. The support portions 44 are spaced at regular intervals and are respectively positioned on the base plate 4 by two fixing screws. The plate 46, which has an end angled at right angles, is disposed facing the hydraulic cylinder 40, and is welded to the claw support portion 25 with one of the two main edges upright. While pressurizing the hydraulic circuit for carrying out the supply to the hydraulic cylinder 40, the shaft 47 (FIGS. 1A and 1B) of the hydraulic cylinder 40 placed on the plate 46 has the claw support portion (B) in front of them. 25) At this time, the rear claw 6 associated with the claw support 25 is opened.

Closing of the rear claw 6 is accomplished by a number of compression springs 48 which press the claw support 25 to close and move in the longitudinal direction after the pressure of the hydraulic cylinder is released. Each spring 48 is guided by a rod of screw 49 extending through the pin plate 46 on which one end of these springs rests. The second end of the spring 48 rests on the plug 50, which is screwed to the support block 51 which is held on the base plate 4 by two screws 52. . In addition, the support block 51 acts as a fixed support for the second shock protection plate 53 partially covering the upper surface of the claw support 25. This protective plate 53 is attached to its base by a plurality of screws 54 (FIGS. 1A and 1B) disposed on the support block 51, and also has a circular hole for accommodating the plug 50.

The transverse positioning of the printing plate 19 on the front claw 5 is ensured by the centering pin 55 (FIG. 4) which is exactly arranged on the longitudinal axis of the printing machine at the top of the front claw 5. .

In FIG. 5B a fastener 60 is shown which is attached to the C.C end of the base plate 4 by screws 61. The roller 11 is positioned on the longitudinal axis of the fastener by screws 62. The two holes 63 near the first 1/3 and the last 1/3 of the base plate 4 have a diameter substantially larger than the diameter of the two bushings 64 penetrating them ( 3). By increasing the size of the hole 63, it is possible to obtain a place necessary for the movement of the base plate 4 in a state of being held flat at the bottom of the groove 1 by the holding means 102, which is the rotation of the plate. This is to control the action of the centrifugal force on the test base plate (4). The retaining means 102 consist of a bushing 64, the two bearing shells 65 of which are made of a synthetic material having a low coefficient of friction around the bushing 64 so that the base plate 4 is easy to move. The plate is sandwiched. Compression spring 66 disposed between two different washers 67, 68, and a screw 69 that is placed on top washer 68 and extends through bushing 64 and then screwed to the bottom of groove 1. Maintains the base plate 4 in a plane parallel to the site of the plate. The fastener 60 also has a hole 70, through which the screw 71 extends, all of which have the same respective functions as the above-described holes 63 and the screw 69.

As shown in FIGS. 5A and 5B, the two rectangular holes 72 in the base plate 4 can accommodate the C.C cam 17 and the C.O.C cam 18 fixed to the plate 3. These holes 72 have a size larger than the dimensions of the base 80 of the cams 17, 18 because the base plate 4 can move freely around this cam without contacting the cam. Because it must be. The hole 72 has three aligned holes in the width direction on each side, among which the center hole 73 accurately positions the reinforcement 74 by two cylindrical pins 75, of which ends The hole 76 is adapted to fix the reinforcement 74 on the base plate 4 by the screw 77. As shown in FIGS. 6 and 7, the reinforcement 74 constitutes two bridges, which are fixed to the base plate 4 and arranged on top of the cams 17, 18, and also In the maximum plane of the bridge, rollers 15 and 16 sliding on each cam 17 and 18 are screwed from the bottom. The screw 78 secures the front claw 5 and the protection plate 22 over the reinforcement 74.

The cams 17, 18 are mutually symmetrical, on the one hand the holes for receiving the centering pins 81, and on the other hand the two screws 82 screwed to the plate 3 are sliding. Stepped base 80 with two fixing holes 83. Two small protrusions 84 that are triangular over this base 80 and make up the core of the cam are raised, and between these protrusions 84 are rollers 15 or rollers depending on whether they are CC cams or COC cams. (16) slides. The rollers 15, 16 slide freely between the longest surfaces of the protrusions 84 oriented obliquely with respect to the axis of rotation 2 of the plate 3.

In order to better understand the working principle of the mechanism of the present invention, three different positions are schematically illustrated in Figs. 8A, 8B and 8C by the positioning device of the printing plate. If the printing plate is not deflected, the arrangement of the mechanisms will be in an intermediate position corresponding to the schematic diagram of Fig. 8A.

If it is necessary to deflect the printing plate in one direction or another direction, the deflection mechanism of the printing plate can be driven by simply moving the plate 3 in the direction of the rotational axis 2. The transverse movement of the plate 3 is adjusted by means 101 comprising an electric motor coupled to a cog wheel engaged in a worm form. This conventional mechanism converts the circular motion of the motor shaft into the linear motion required for the transverse motion of the plate. The movement of the plate and the motor by this mechanism is further automated by the sensors that detect the transverse movement of the plate. This sensor is connected to an external electronic controller (not shown) that controls the motor of the means 101. Thus, for certain operations, the deflection of the printing plate is easily controlled and stored by the electronic controller, through the position sensor, and by simply storing the transverse movement of the plate.

As shown in FIG. 8B, when the plate 3 moves from C.O.C to C.C, the roller 11 abuts against the side 12 of the cam ring 14 after some stroke. This results in a combined movement of the base plate 4 guided by the rollers 15 and 16 sliding on the cams 17 and 18, the combination of which is based on the roller 11. And a translational movement of the base plate characterized by the turning of (4) and the upward sliding movement of the roller 11 along the side surface 12 of the cam ring 14. The slide 9 of the rear claw 6 sliding only in the longitudinal direction on the roller 10 is rotated and translated about a fixed pivot made up of the roller 10 fixed to the plate 3. Allow. Due to this longitudinal orientation of the slide 9, no movement along the axis 2 is transmitted to the rear claw 6. Thus, due to this rear claw 6 not moving in a direction parallel to the axis 2 of the plate barrel, and also due to the combined movement along the front claw 5, the front and rear edges of the printing plate are parallel to each other. Even staggered movements can be biased.

FIG. 8C shows in the opposite direction the same combined motion resulting from the motion of the plate 3 from C.C to C.O.C. In this case, the roller 11 abuts and slides along the opposite side 13 of the cam ring 14.

In order to correct the deflection positioning state of the printing plate 19, the operator releases the pressure of the hydraulic cylinder 40 slightly so as to loosen and detach the printing plate from the plate 3, and furthermore, in one direction or another direction, the plate ( 3) operate the motor of the means 101 to move. When the roller 11 in contact with one side 12 or 13 of the cam ring 14 moves along the cam ring 14 by a distance corresponding to a desired deflection state, the plate 3 is a transverse register suitable for printing. Move in the opposite direction to reposition the roller. Since the roller 11 is immediately released from the side of the cam ring 14 during this opposite movement, the movement of the plate does not change the deflection state of the printing plate 19 at all. Since the printing plate 19 is extended and attached to the plate 3, the biased position of the printing plate is maintained. Since the position of the transverse register of the plate 3 is known, it is possible to easily automate the deflection of the printing plate by this angle value simply by inputting the angle value to the electronic controller, if desired.

Therefore, the process of positioning and deflecting the printing plate on the plate on which the apparatus according to the present invention is installed is as follows.

a) opening the rear claw 6 by a hydraulic cylinder 40 compressing the spring 48,

b) securing the front edge of the printing plate 19 to the notch 7 of the front claw 5 and to the centering pin 55,

c) slowly rotating the plate 3 about the axis 2 to wind the printing plate 19 around the plate,

d) fastening the rear edge of the printing plate 19 to the notch 8 of the rear claw 6,

e) closing the rear claw 6 by releasing pressure in the hydraulic cylinder 40,

f) actuating the hydraulic cylinder 40 so as to slightly detach the printing plate 19 from the plate to deflect, and rapidly rotating the plate 3,

g) deflecting the printing plate 19 by moving the plate 3 in the transverse direction by a predetermined distance corresponding to the desired inclination,

h) transversely moving the plate 3 to recover the transverse register necessary for printing, and

i) releasing the pressure in the hydraulic cylinder 40.

Each of the above operations can be easily automated by the idea and mechanism of the present invention for not only fixing the printing plate around the plate but also deflecting the printing plate. Effectively, when resuming a previous print job, the device does not require any manual adjustment of the printing plate, if previously known adjustments are stored. Finally, even when the plate is rotated at the maximum speed, the printing plate can be biased. Therefore, it is not necessary to stop the printing machine in order to correct the inclination position of the printing plate, thereby reducing the operating cost when preparing a new printing job. Various modifications may be added within the scope of the claims of the present invention.

The present invention relates to a positioning device of a flexible printing plate on a plate, in particular an apparatus for deflecting such a flexible printing plate on a plate of a rotary press, in accordance with the present invention on the one hand an actuator provided in advance for lateral adjustment of the printing plate. It can be used more reasonably, and on the other hand, it is inexpensive and compact, but it has the effect of obtaining a deflection mechanism that is robust and reliable, and can be easily applied to the plate without any other mechanism.

Claims (10)

A positioning device for positioning a flexible printing plate 19 on a plate 3, wherein the device can deflect the printing plate in a rotary press, and the plate 3 having the rotational axis 2 has the rotational axis ( A positioning device having a groove 1 arranged in parallel with 2), wherein the positioning device of a printing plate is disposed in the groove 1, The positioning device is arranged outside of the plate 3 by the transverse movement of the plate 3 carried out by the external means 101 fixed to the frame of the printing machine and opposite the outer means 101. Actuated by a cam ring 14, the roller 11 being fixed to the movable base plate 4 on the inner edges 12, 13 of the cam ring 14, the base plate 4 being held Freely held relative to the plate 3 by means 102 and two cams 17, 18, the cams 17, 18 being firmly attached to the bottom of the groove 1 of the plate 3 and having a foundation. A positioning device, characterized in that for adjusting the backward tilting motion of two rollers (15, 16) constrained to a plate (4). 2. The external means (101) according to claim 1, wherein the external means (101) for operating the positioning device of the printing plate consists of a mechanism and a motor which permits the conventional lateral movement of the plate (3) along the rotation axis (2). And a numerical controller for measuring and storing the direction and the value of the transverse motion of the plate using a conventional sensor arranged in the frame of the printing machine. The rectangular cam according to claim 1, wherein each of said cams (17, 18) is precisely positioned and fixed at the bottom of the groove (1) of the plate (3) by a screw (82) and at least one centering pin (81). A base 80, further comprising two triangular protrusions 84 disposed above the base 80, the rollers 15, 16 being protrusions oriented obliquely with respect to the axis of rotation 2 of the plate 3. Positioning device, characterized in that it can freely slide between the longest surfaces of (84). 2. The base plate (4) according to claim 1, wherein the base plate (4) has two rectangular holes (72) each having a dimension larger than that of the base (80) at a place occupied by the cams (17, 18) for passage. A plurality of holes 73 and 76, which are adjacent to the holes 72 of the stiffeners and which can firmly and accurately receive and fix the two reinforcements 74 supporting the rollers 15 and 16, and are spaced at regular intervals. Another hole 63 capable of receiving therein the holding means 102 of the base plate 4 relative to the plate 3, and the base plate 4 supports the front claw 5, The length of this front claw 5 is substantially the same as the length of the groove 1, the front claw 5 is firmly attached to the base plate 4 by the block 20 and the support 44, The rear claw 6 is arranged to face the front claw 5 and is held by the fixing means 103 on the claw support 25, Group claw support (25) is a positioning device as claimed in only one parallel to the longest side of the base plate 4, the direction that is movable independently of the rear claw (6). 2. The retaining means (102) according to claim 1, wherein each retaining means (102) consists of a bushing (64), a compression spring (66) and an upper washer (68), said bushing (64) of the hole (63) through which the bushing passes. It has a diameter slightly smaller than the diameter, and the circumference of the bushing 64 is successively laminated with the washers 68 placed on the bearing shell 65 installed at a fixed position on the base plate 4, A positioning device, characterized in that a head of a screw (69) extending through a bushing (64) overlying the upper washer (68) for screwing into the bottom of a groove (1). 5. The reinforcement (74) according to claim 4, wherein the reinforcement (74) constitutes a bridge, and on the maximum surface of the bridge, rollers (15, 16) are screwed from below, and the reinforcement (74) has a respective cam (17). Positioning device, characterized in that arranged on the base plate (4) at the top of the (18). 5. The claw support portion (25) according to claim 4, wherein the claw support portion (25) is made of a metal plate, the length of the metal plate being substantially the same as the length of the front claw (5), the metal plate being constant in a direction parallel to the long side of the metal plate. A plurality of elongated holes 26 arranged at intervals are provided, the fixing means 103 consisting of studs 27 penetrating the holes 26, and the studs 27 are provided on the claw support 25. Screws 28 holding rear claws 6 are screwed on, and the claw supports 25 are mounted on at least two blocks 30, each of which blocks 30 of the base plate 4. The rear claw slides over an axis 31 oriented perpendicular to the length and the end of the axis 31 is held by two supports 32 screwed to the base plate 4. 6 and the claw support 25 are closed of the rear claw 6 And at the time of movement to realize the opening along the axis 31 it is positioned, characterized in that to sliding apparatus. 8. The closing of the rear claw (6) is carried out by means of a plurality of compression springs (48), each of which is provided on a support block (51) fixed to the base plate (4). And press the rear claw 6 toward the front claw 5 using a plurality of plates 46, the plate 46 being disposed upright at right angles to the claw support 25 and the claw support Positioning device, characterized in that fixed to the lower surface of (25). 9. The opening of the rear claw 6 is carried out by a plurality of hydraulic cylinders fixed on the support 44, wherein the shaft 47 of the plurality of hydraulic cylinders is a spring 48. Positioning said plate (46) in order to compress it. 9. The support block (51) according to claim 8, wherein each of the support blocks (51) is provided with threaded holes for passages of the respective compression springs (48), which plugs (50) function as supports of the springs (48). Positioning device characterized in that the screwed.