JP3244667B2 - A fixing device for fixing a plate to a printing press cylinder, especially a plate cylinder of a sheet-fed offset printing press. - Google Patents

Abstract

The plate fixing device has a clamping rail composed of upper and lower parts with a gripping region for the plate between them. The first operating device (11) can open the closed clamping rail (3) and take it from the open position into a pre-closure position. There is also a second operating device, by which the clamping rail can be moved from the pre-closure position to a position in which it is closed on the plate with sufficient force to hold in place. The lower part (4) of the rail is moved radially relative to the lower part (5) by a shaft (6) with cams (7) on it.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixing device for fixing a plate on a printing press cylinder according to the preamble of claim 1.

[0002]

2. Description of the Related Art In a sheet-fed offset printing press, a plate formed as a plate or a sheet is fixed on a plate cylinder by a clamping device. For this purpose, the plate cylinder has, in grooves parallel to its axis, clamping rails provided at the printing start and at the printing end of the plate, in which the respective ends of the plate are respectively fixed. You. Such a clamping device consists, for example, of upper and lower elongated clamping strips, which extend integrally or in a divided manner over the format width of the cylinder, and Operable to an open position to introduce each end region of the plate. The fixing of one plate end is effected by applying force to the two clamping strips and approaching each other, i.e. the two clamping strips sandwich the plate between them and cause the fixing of the plate. They are pressed together by force.

[0003] DE 41 29 831 discloses a plate clamping device. This fastening device comprises an upper, stationary fastening strip and a lower, radially movable fastening strip. The movable lower clamping strip is held in the closed position by the force of an associated spring, the force required for clamping the plate being generated by this spring. An operating device is provided for opening the closed clamping strip and releasing the plate, which is operated by the above-mentioned spring force to open the plate gripping gap clamping the plate. Resist
Push down the lower tightening strip.

In this type of device, a spring member for generating a force for fixing the printing plate must be integrally incorporated and disposed in a clamping rail of the clamping device, and as a result, the production of a corresponding part is expensive. It has the disadvantage of requiring a production cost. The spring element makes it possible to automatically adapt the plate gripping gap to different plate thicknesses, but the plate gripping gap, when the clamping device is opened, is It can only be opened up to the point where the value is reached. The small plate gripping gap makes it difficult to introduce the plate edge into such a clamping device. Therefore, when the supply of the plate is automated, troubles during the process cannot be eliminated.

[0005] According to DE 26 06 733,
A fixing device for fixing a flexible printing form on a printing press cylinder is known, in which an immovable upper clamping strip and a radially movable lower clamping strip cooperate with one another. It is. As in the previously described device, the plate is introduced into the opened plate gripping gap and then clamped. The operating device for closing the printing form is in this case connected in series with the spring element, which allows for limiting the force and thus also adapting to different plate thicknesses. To open the tightening device, the spring member is relaxed to move the lower movable tightening strip to the open position.

[0006] Since this device does not over-press the spring to open the clamping device, this device provides a relatively large opening gap that facilitates the introduction of the plate edge. it can. However, this tightening device also has a large number of spring members that are integrally incorporated in the tightening rail, and thus the manufacturing cost is high. Furthermore, in a clamping device having an open gripping gap for the plate, just another object (eg a tool) enters the gripping gap that has to be widely opened, which facilitates the introduction of the plate edge. It has to be taken into account that when operating the tightening force, the operating device or the tightening device can be deformed or completely destroyed.

Furthermore, in the plate clamping device, the upper and lower clamping members can be operated via a rotatable cam shaft or an eccentric shaft to an open position and a closed position for fixing the plate. Is known. The camshaft or the eccentric shaft extends outwardly from the two end faces of the barrel and has lever members, each of which cooperates with one operating member, for example, configured as a pneumatic cylinder. It is supposed to. When the pressure medium is loaded on one of the operating members, the tightening device is opened, and when the pressure medium is loaded on the other operating member, the closing device is closed, and thus the plate is tightened. However, this known device is provided with a device for preventing the clamping device or its operating device from being damaged if an excessively thick object enters the open plate gripping region of the clamping rail. Not been.

Further, in a plate cylinder of a sheet-fed offset printing press, a tightening device (a tightening strip) provided at a printing start end.
A sensor formed in the form of a registration needle, which is electrically scannable in particular, is arranged in the inside, and it can be checked by the sensor whether the plate is correctly registered and abutted. It is known that tightening of the part is initiated. In such a device, tightening is performed only when the plate is correctly registered and applied, but the tightening of the plate in connection with foreign matter or the corner or edge area of the plate is It is unavoidable that a plate that has been folded back to an unacceptable thickness is clamped.

[0009]

The object of the present invention is therefore to improve a fixing device according to the preamble of claim 1,
In addition to avoiding the disadvantages mentioned above, a technically simple construction for the fixing device is obtained, whereby the plate can be fixed with sufficient fixing force and excessively thick objects can be fixed. The present invention is intended to prevent the fixing device from being destroyed even when it is grasped.

[0010]

This object is achieved according to the invention by means having the features of patent claim 1. Further embodiments of the invention are set out in the dependent claims.

According to the invention, preferably, a fixing device comprising an immovable upper tightening strip and a radially movable lower tightening strip is fixedly supported on the body and Operable via an eccentric shaft located below the lower clamping strip. The pivoting of the eccentric shaft takes place in this case via two operating devices, in which case the first operating device moves the clamping rail from the closed position to the open position and to the open position (plate introduction). Position) to a pre-closed position with a gripping gap width corresponding to the maximum plate thickness, and complete closing, and thus also clamping of the plate, is effected from said pre-closed position by a second operating device. At this time, the fixing force required for fixing the plate is generated.

In this case, the first actuating device, which provides the open and pre-closed positions, exerts a lower force than when fully closed, so that an excessively thick object in the open gripping area of the clamping rail. Even when there is no damage to the corresponding parts. In the pre-closed position, the plate thickness is therefore measured and the final closing is only performed when it is determined that the plate has a maximum allowable thickness or less.

[0013] The activation mode of the first and second operating devices is such that after the activation of the first operating device, the lower tightening strip is moved from the open position to a predetermined reserve corresponding to the maximum plate thickness that can be processed. Only when the closed position has been reached is the second operating device, which produces the final plate-fixing force, is activated. If a foreign object (e.g., a tool) or an overly thick plate (e.g., a plate with folded edges or corners) is introduced into the open gripping area between the upper and lower clamping strips, the lower After activation of the first operating device, the clamping strip does not reach the pre-closing position corresponding to the maximum plate thickness that can be processed, since the closing force is relatively weak.

According to the invention, the reaching of the pre-closed position corresponding to the maximum plate thickness can be ascertained by a sensor associated with the first operating device. The first operating device, as will be described in detail later,
If the cylinder is operated as a retractable pneumatic cylinder and operated at reduced pressure to produce the pre-closed position, the pre-closed position is reached by a sensor (proximity switch) by means of a pneumatic It is monitored by detecting the markings on the piston rod of the cylinder or on the lever actuated by the piston rod. If there is no excessively thick plate in the open gripping gap, the pre-closed position is reached by the activation of the pneumatic cylinder as the first operating device and a corresponding sensor signal is output (first). The piston rod delivery position of the operating device).

When the corresponding sensor signal is detected by the control means for loading the first operating device with the pressure medium, the load of the pressure medium on the second operating device (reversing pneumatic cylinder) is reduced. As a result, the lower clamping strip is pressed from the pre-closed position into the closed position with a predetermined force for fixing the printing form. As a result, the eccentric plate for moving the lower tightening strip is turned (rotated) to a predetermined end position.

If the lower tightening strip has not been completely moved from the open position to the pre-closed position by the load of the pressure medium on the first operating device (in the absence of a sensor signal), this process will take place. Indicates an abnormal closing process caused, for example, by an excessively thick plate thickness or foreign matter in the gripping gap between the upper and lower clamping strips. In this case, an error signal is issued and the operator inspects the device,
In some cases, the cause of the failure must be eliminated.
No pressure medium is applied to the second operating device, and the first operating device is controlled such that the lower tightening strip is returned to the fully opened open position again.

Thus, an advantageous embodiment of the present invention has been described in which the pre-closure position is monitored by a sensor. Instead of monitoring by means of a sensor (run-out position of the piston rod), it is also possible for the mechanism cooperating with the second operating device of the eccentric shaft to be constructed as follows: the lower clamping strip Only has reached the pre-closed position, and thus only when the eccentric shaft also assumes the predetermined rotational angle position, the second operating device pivots the eccentric shaft with the predetermined maximum force. It is also possible to configure so that it can be performed. This can preferably be done by giving the lever located at one end of the eccentric shaft a suitable shape cooperating with the second operating device.

A fixing device according to the invention can be provided at the printing start and end of the plate cylinder for fixing the plate. In particular, a particularly high clamping force is required for fixing the printing end of the plate, but this clamping force can easily be obtained by a suitable configuration of the second operating device. The introduction of the printing end of the plate into the fixing device is facilitated by the wide opening of the clamping gap (gripping area),
Therefore, the fixing device according to the present invention can be suitably used in a semi-automatic or fully automatic plate changing system.

[0019]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a plan view of a fixing device configured as a tightening rail; FIG. 2 is a cross-sectional view of a fixing device including upper and lower tightening strips with an eccentric shaft disposed on a lower side; FIG. FIG. 4 shows the first operating device when the rail is in the open position; FIG. 4 shows the first operating device when the tightening rail is in the pre-closed position; FIG. 5 shows the tightening rail completely closed. FIG. 6 shows the first operating device in the closed position; FIG. 6 shows the second operating device when the tightening rail is in the pre-closed position; FIG. 7 shows the closed position in which the tightening rail is completely closed. FIG. 6 is a diagram showing the second operation device when the second operation device is in the state of FIG.

FIG. 1 shows a cylinder 1 which functions as a plate cylinder of a printing press. The cylinder 1 has a groove 2 parallel to its axis, in which a clamping rail 3 provided at the printing start of the plate is arranged as a device for fixing the plate.

The tightening rail 3 as a plate fixing device is shown in FIG.
According to U.S. Pat. No. 5,073,867, there is an appropriately shaped bar in the form of a bar having an upper part 4 which is immovable with respect to the cylinder and a lower part 5 which is movable in the radial direction, which lower part 5 is also produced as a bar. ing. Below the radially movable lower part 5, a shaft 6 which is stationary with respect to the cylinder and is rotatably mounted in a support 8 which is arranged at a distance from one another is parallel to said lower part 5. The shaft 6 has an eccentric 7 between the bearings 8. The outer circumference of the eccentric 7 cooperates with the lower surface of the lower part 5 in the manner shown, so that the rotation of the shaft 6 operates the lower part 5 to open and close the tightening gap. The direction of movement of the lower part 5 and the eccentric 7 is indicated by a two-way arrow. The lower part 5 is pressed in this case by an unillustrated spring element into the open position and thus toward the outer periphery of the eccentric 7. The lower part 5 simultaneously pivots the shaft 6 via the eccentric 7 into the "open" position by means of these spring elements. Therefore, the lever 10 provided on the first operating device 11 at one end of the shaft 6 has been rotated to the position shown in FIG. From this position of the lever 10 then the pivoting of the shaft 6 to actuate the lower part 5 to its pre-closed position, ie the pre-closed position, takes place (FIG. 4).

FIG. 1 shows a configuration in which the shaft 6 extends outward from the end portions on both ends of the body 1. The shaft 6 has a lever 9, 10 at its end on either side, via which the movement of the shaft 6, and thus of the lower part 5, described below, takes place. Can be On the pivotable ends of the levers 9, 10, an operating device, not shown in FIG. 1, acts, which is fixed relative to the frame and in which the cylinder 1 corresponds to one of the corresponding positions. Acts on the ends of the levers 9 and 10 when they are in one position.

3 to 5 show the first operating device 11,
This operating device 11 cooperates with a lever 10 on one end face side of the barrel 1 in FIG. The first operating device 11 comprises in this case a pneumatically operable working cylinder 12 pivotally mounted at one end (not shown), the working cylinder 12 comprising a piston rod 13. The free end of the piston rod 13 is pivotally connected to one arm of a two-armed lever 14 having two arms. In this case, the lever 14 is rotatably supported on a hinge shaft 15 which is immovable with respect to the frame. The lever 14 has, on the other second arm, a roll 16 rotatably supported on the shaft 6.
In cooperation with the profile 17 of the lever 10 of FIG. FIG. 3 shows the clamping rail 3 in a fully opened position, in which the lower part 5 is in the lowest position for introducing the plate 18 into the fully opened gripping gap. .

FIGS. 6 and 7 show a lever 9 which is arranged on the opposite side of the barrel 1 and which has a second operating device 19. This second operating device 19 comprises a working cylinder 20 having a piston rod 21 which is in this case pneumatically operable and which is immovably arranged, at the end of which a roll 22 is arranged. ing. This roll 22 cooperates with the free end of the lever 9 at the corresponding end of the shaft 6 in this case.

Starting from the fully open position, the clamping rail 3 (lower part 5) for introducing the end of the plate 18 into the open gripping gap shown in FIG. By the control of the operating device 11, the lower portion 5 is moved to a so-called preliminary closed position shown in FIG. For this purpose, the piston rod 13 is delivered to the delivery-side end position by the load on the working chamber of the working cylinder 12. The working chamber of the working cylinder 12 is loaded with a predetermined pressure medium for this purpose. This can be done by switching the pressure reducing valve first. In this way, the pre-closed position of the lower part 5 by the corresponding pivoting of the lever 10 from the position shown in FIG. 3 to the position shown in FIG. 4 is obtained with a force less than the final clamping force. Is guaranteed.

At the position where the piston rod 13 has been delivered, a sensor 23 is provided to check whether the lower part 5 is actually in the pre-closed position.
3 cooperates with a marking 24 provided on the rod of the piston rod 13 so that when the piston rod 13 is completely delivered, a signal can be accurately transmitted. The marking 24 may be a permanent magnet that cooperates with a sensor 23 that detects a magnetic field.

As can be seen by comparing the position of the lever 10 in FIGS. 3 and 4, if there is an excessively thick object in the gripping gap between the upper part 4 and the lower part 5, the lever 1
0 cannot pivot to the position of FIG. 4 and therefore the piston rod 13 is not completely delivered due to the reduced pressure in the working cylinder 12. Therefore, in this case, the marking 24 does not reach the position facing the sensor 23,
No signal is transmitted from the sensor 23. The sensor 23 is operatively connected to a control device for initiating the illustrated working process, which applies a pressure medium to the working chamber of the working cylinder 12 via an electromagnetically switchable valve.

Starting from the pre-closing position of the clamping rail 3 (lower part 5) shown in FIG. 4 (which is also shown in FIG. 6), the plate 18 enters The closing of the gripping area is performed by the piston rod 2 of the second operating device 19.
1, whereby the roll 22 at the end of the piston rod 21 acts on the upper surface of the lever 9, thereby rotating the shaft 6 and rotating the eccentric 7 on that shaft together. Let it. This closing step is illustrated once more in FIGS. FIG. 5 also shows the closed, closed position of the lower part 5 for securing the plate 18.

During operation of the printing press, the lever 14 assumes the position indicated by the dashed line in FIG. 5 with the first operating device due to the complete retraction of the piston rod 13. Thus, the roll 16 at the end of the lever 14 cannot come into contact with the end of the lever 10 in the closed position. In order to open the clamping rail 3 (lower part 5), the piston rod 13 of the first operating device 11 is completely delivered (see FIGS. 5 to 4), so that the roll 16 at the end of the lever 14 is released. Profile 17
, Thereby pivoting the lever 10 with the shaft 6 to the pre-closed position of FIG. The piston rod 13 is then completely retracted again, so that the lower part 5 is completely opened by the spring force, whereby the lever 10 is pivoted into the position shown in FIG.

[Brief description of the drawings]

FIG. 1 is a plan view of a fixing device configured as a tightening rail.

FIG. 2 is a cross-sectional view of a fixing device including upper and lower tightening strips in which an eccentric shaft is arranged on a lower side.

FIG. 3 is a side view showing the first operation device when the tightening rail is at an open position.

FIG. 4 shows the first state when the tightening rail is in the pre-closed position.
It is a side view which shows the operation device of FIG.

FIG. 5 is a side view showing the first operating device when the tightening rail is in a completely closed position.

FIG. 6 shows the second state when the tightening rail is in the pre-closed position.
It is a side view which shows the operation device of FIG.

FIG. 7 is a side view showing the second operating device when the tightening rail is in a completely closed position.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 body (plate cylinder) 2 groove 3 tightening rail 4 upper tightening strip (upper part) 5 lower tightening strip (lower part) 6 eccentric disk shaft 7 eccentric disk 8 support base 9 lever 10 lever 11 First operating device 12 Working cylinder 13 Piston rod 14 Lever 15 Hinge shaft 16 Roll 17 Profile 18 Edition 19 Second operating device 20 Working cylinder 21 Piston rod 22 Roll 23 Sensor 24 Marking

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-8-169101 (JP, A) JP-A-3-161336 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B41F 27/12

Claims (9)

(57) [Claims] 1. A fixing device for fixing a plate to a cylinder of a printing press, in particular to a plate cylinder of a sheet-fed offset printing press, comprising a clamping rail comprising an upper part and a lower part, an upper part and a lower part. A gripping area formed between the parts for gripping the printing form, and an operating device by means of which the gripping area can be opened and closed to fix the printing form. In one version, a first operating device (11) is provided, by means of which the closed clamping rail (3) is opened and from this open position the maximum plate. It is operable to a pre-closed position having a gripping gap width corresponding to the thickness and a second operating device (19) is provided, by means of which the clamping rail (3) is provided. From the pre-closed position, the force causing the plate to be fixed , Intended to be closed, the first operating device (11) has a sensor (23),
The tightening rail (3) is preliminarily closed by the sensor (23).
It is possible to confirm whether or not the
(23) issues control of the second operating device (19).
A fixing device for fixing a plate to a cylinder of a printing press, in particular a plate cylinder of a sheet-fed offset printing press, operatively connected to a control device to be moved . 2. The fixing device according to claim 1, wherein the clamping rail comprises an upper part and a lower part radially movable with respect to the upper part. An eccentric (7) provided on said shaft (6) by means of a shaft (6) arranged therebelow.
A fixing device, which can be opened and closed. 3. The fixing device according to claim 2, wherein the lower part is operable in an open position by means of an associated spring element. 4. The fixing device according to claim 1, wherein the body (1) has one lever (9, 10) at each end on both end faces thereof, One of the levers (10)
Cooperates with the first operating device (11) and the other lever (9) cooperates with the second operating device (19). 5. The fixing device according to claim 4, wherein the first and second operating devices (9, 10) are arranged immovably with respect to the frame, so that these operating devices (9, 10). Act on the levers (9, 10) after rotation of the body (1) to a predetermined position. 6. The fixing device according to any one of claims 1 to 5, preferably the first operating device (11) is constructed as actuatable working cylinders in pneumatic (12) A fixing device. The fixation device of claim 7. wherein any of claims 1 to 5, that the second operating device (19) is preferably designed as working cylinders which can be actuated pneumatically Characteristic fixing device. 8. The fixing device according to claim 6 , wherein the piston rod (13) of the working cylinder (12) of the first operating device (11) is supported on a hinge shaft (15) that is stationary with respect to the frame. A fixing device, which acts on a lever (10) of a tightening rail (3) via a double arm lever (14). 9. The fixation device according to claim 8, wherein the lever is configured as a double-armed lever having a profile.