EP1840061A1 - Active sheet feed and guide elements - Google Patents

Abstract

The printing unit (5) is arranged in an area of a recess of a cylinder surface from a surface of a print substrate. The printing unit is displaceably arranged as a component part of an active spring over a piezo-composite (2) in the direction of a conveyor, and is composed of a combination of a spring material and a piezo-composite. The printing unit is designed as a coding unit that is attached by using the active spring against a print substrate sheet.

Description

The invention relates to active sheet guiding / sheet guiding elements and monitoring devices for use in rotary printing presses or in printing finishing machines according to the preamble of claim 1 or 2.

Pressing means, such as pressure rollers, hold-down plates, hold-down bars, brushes, brush strips or hold-down rollers are used in a variety of rotary printing presses, in copying machines and in further processing machines for printed products. They serve to fix the printing substrate or printed products on a conveyor, such as a conveyor belt or on a cylinder for the purpose of trouble-free transport and to avoid lifting of the printed product. Pressing means are also used to prevent the lifting of the sheet end, for example, to avoid damage to the printed product when the sheet, for example on a cylinder, is deflected. Printing substrates in the context of the invention may be paper or cardboard sheets, corrugated sheets, paper or cardboard sheets, corrugated cardboard sheets, metal sheets, plastic sheets or plastic film webs. Printed products in the sense of the invention can be any printed substrate printed in any printing process, but also printed products formed from the printed Drucksubstart, such as folding box blanks, glued carton, folded printed products, brochures or booklets and individual components thereof.

In addition to the known applications of pressing agents in printing presses, a multiplicity of different applications are used in apparatus for the further processing of printed products. The patent specification describes by way of example US 5,439,209 has a paper stacking device for a copying machine that is suitable for separating successive elements. The device has a conveyor belt, wherein a holder is mounted above the conveyor belt. The holder holds a series of freely rotatable balls, which the leaves on a Press tape. Partial stacks are formed and laterally offset from each other to separate printed products from each other. The patent DE 101 55 052 C1 describes a hold down for fixing a stack of sheet material. The hold-down is mounted on a height-adjustable and fixable support arm.

In the patent DE 198 11 698 C2 An apparatus for collecting sheets of a recording medium will be described. The leaves are collected successively on the circumference of a drum. Recesses are provided in the circumference of the drum, in which drivable transport rollers are provided. The transport rollers thus interact with pressure rollers, which are pivotable against the transport rollers. The transport rollers and the pressure rollers serve on the one hand for clamping the bundled sheets on the drum, on the other hand for ejecting the entire bundle. Also, various pressing means for supporting the sheet transport from folding machines, gathering machines and Faltschachtelklebemaschinen are known. All of these applications usually require an adjustment of the height or the contact pressure of the pressing means. The requirements are sometimes even significantly higher than in printing presses, since in contrast to the flat printing substrates folded, stamped or further processed in another way products are fixed by the pressing means. Due to the collars in the combined booklets of a booklet, by the fold or by the folding edges of a folding carton, even greater demands on the pressing means arise because the printed products are not flat and often additionally scaled.

Pressurizing two essential requirements: You must exert sufficient force on the printing substrate or the printed product, so that the printing substrate is fixed in the desired position, but at the same time the pressure must not be too large, to prevent damage to the printing substrate or the printed products.
Especially in the case of pressure-sensitive printing substrates and printed products, only a compromise between the two requirements can be found. Especially The situation is difficult when the printing substrate or the printed products are conveyed in a scale flow, since the contact pressure changes depending on the number of layers. Damage to the printing substrate is trying to avoid by the pressure means are employed feathers. In most cases, the contact pressure such pressing means is set with fixed or adjustable springs. An adjustment of the spring force is usually done manually, a procedure that is no longer justifiable in today's highly automated printing and finishing machines. A generic representative of such Andrückmittel is in a design as hold-down over a side mark in the DE 103 57 864 A1 and as a pressure roller on a conveyor belt in the DE 31 45 364 A1 disclosed.

The adjustment to the thickness of the printing substrate or on the thickness of the printed product is usually done manually in most known solutions for pressing. Although there are solutions that make a height adjustment of hold-down automated, but these solutions are usually very expensive and costly.

That's how it describes DE 32 27 092 C2 a hold-down for corrugated board blanks, which has a hold-down brush which is fixedly mounted on an arm by means of a mounting rod, wherein the lever arm is connected via a rod with a cam. The swivel movement is adjusted via a controller.

In order to adjust the top brands of landing marks a sheetfed press on the strength of the processed sheets, it is from the DE 42 39 254 C2 known to store the positioning marks in a pivoting allowed to store points and run this frame points adjustable in their altitude by a control gear. Thus, the application marks can be moved perpendicular to the feed table and the distance between the deck marks and the investment table of the material thickness can be adjusted.

The DE 102 22 055 A1 describes a device for adjusting the sheet holder of a page mark on the processed, conveyed on a feed table sheet material in a printing press. The height adjustment of the hold-down is done by this is set with a control gear this to the substrate height.

The previously cited solutions are very expensive and do not allow dynamic adjustment of the contact pressure during the conveying process by regulating and / or controlling the contact pressure. Such a dynamic adaptation makes sense, for example, if printed substrates or printed products are fanned or scaly. With a dynamic adjustment can be achieved that the contact pressure for fixing at any time is sufficient to push the print substrate or printed product safely, but the contact pressure is still at any time so great that there is a risk of damage to the printing substrates or the printed products. In addition, all hitherto cited adjustable pressing means only have control according to fixed default values. Although these can be subsequently corrected in some pressing means, but a dynamic change is not provided. A self-correction or self-adjustment of the pressing means, for example by measuring the contact pressure is also not known. This would significantly simplify and accelerate a set-up process.

For certain applications, also pressing means must be clocked running. The timing is required to ensure a trouble-free inlet of printing substrates or printed products in the Andrückspalt between Andrückmittel and conveyor, such as a rotating shaft. A typical application for such timings are timing rolls in investors for sheetfed presses. The FR 2 318 090 shows a device for transporting sheets in a sheet-processing machine, which is arranged on a clocked shaft and can be pressed with an adjustable contact pressure to a transport shaft, the device having a rotatably mounted roller which is arranged vertically adjustable and axially displaceable. The US 1,910,506 also shows a device for transporting sheets to a sheet-processing printing machine, which is arranged on a clocked shaft and with an adjustable pressure against a conveyor roller. In the EP 0 679 593 B1 a take-off roller is described in which the height-adjustable element of a control roller is a spring plate with a predetermined bending line. The bending line of the spring plate is calculated so that the contact pressure in a defined range can be changed. As an alternative solution, the height-adjustable element consists of two levers, wherein the clock roller is adjustable via a pivot point and a compression spring to the desired pressure.

In other areas of the printing press clocking pressing means are known. The patent DE 35 21 590 describes a Bogenglättvorrichtung having above the contact sheet of a printing press a bar which is arranged movable up and down in the gripper edge of the applied sheet, each raised by a control device when removing the sheet by the pre-gripper and smoothing the gripper edge of the subsequent sheet is lowered again. The utility model DE 87 03 993 U1 describes a similar device, except that it is the pressing means is a clocking brush strip.

It is useful to provide clocking pressing means for fixing sheets on a sheet leading cylinder to prevent lifting of the sheet end. Continuous fixing of a printing sheet is advantageous if the entire sheet is to be inspected with an sheet inspection device, or the printed sheet is to be printed with an ink jet device. In both cases, a change in distance by lifting the end of the sheet leads to a falsification of the result. This fixation is difficult to perform by fixed roles, otherwise the pressing would run against the gripper of a sheet leading cylinder of a sheet-fed press and could get into vibration. In addition, starting against the grippers will lead to higher wear.

It is well known that by utilizing a so-called piezoelectric effect, a piezoelectric element can be constructed of a material having a suitable crystal structure. When an external voltage is applied to these piezoelectric and electrorestrictive ceramics, a mechanical reaction of this piezoelectric element takes place which, depending on the crystal structure and the contact regions of the electrical voltage, represents a pressure or tension in a predeterminable direction. In the patents US 5,443,257 and the EP 1 172 317 B1 Among other things, it is proposed to adjust the distance of a scanning element to a substrate or printing material by means of a piezoelectric actuator, which is formed from piezoelectric materials.

The US 5,443,257 shows a device for transporting banknotes. This has, inter alia, a standing in contact with the bills friction roller, which is equipped with an idle and should prevent that more than one sheet is transported simultaneously. The distance to the material to be conveyed is adjusted with a piezo actuator. The piezoelectric element may have a change in length of up to 15 microns, which bring about a lever translation to a distance change of a maximum of 300 microns between the cam follower and counter-roller. The in the patent US 5,443,257 Device described expressly has a control function, no transport function. The transport of the banknotes is done by the device separate role pair. The cam follower is easily moved up and down via the piezo actuator to ensure that each bill is safely transported. A dynamic adjustment (timing) of the cam followers against the material to be conveyed, depending on the production speed, is also described in the said patent. This timing or up and down movement is initiated by the piezo actuator and implemented via the lever arm.

The EP 1 172 317 B1 describes a device and a method for controlling the sheet flow structure or the sheet flow, wherein during its transport in a sheet-processing machine at least one probe element in the direction of a counter-pressure element is displaceable over which the shingled or sheet-fed sheet-fed, that is transported. The method is characterized in that the probe element is turned on the sheet flow, that is pressed with a defined force and this detected during its transfer into the machine, such as a sheet-fed press. During the monitoring of the arc current, the probe element is always displaced as a function of the respective instantaneous arc current thickness relative to the arc current, that the contact force with which the probe element is pressed against the arc current is maintained at a predeterminable value or within a predeterminable value range. By means of a suitable sensor system, the path is determined, which is the probe element against the preferably fixed, for example, formed by a feeder table counter-pressure element displaced. As a result, the thickness of the arc current can be determined or measured very precisely, so that double and missing arcs are readily detected, which leads to the output of an error signal, for example. Furthermore, by means of the change in distance of the probe element relative to the counterpressure element, including the respective instantaneous machine speed, early, late and oblique curves can also be detected. The method is characterized by high accuracy and also has a high reliability. It is also particularly advantageous that due to the constant held contact pressure of the probe element to the counter-pressure element, the measurement conditions are constant regardless of the respective arc current thickness. It is therefore easily possible to automate the arc or the sheet thickness measurement and / or the arc current monitoring.

The to the EP 1 172 317 B1 associated monitoring device is characterized in that the scanning element is displaceable with an adjusting device in the direction of the arc current, wherein the actuator has at least one piezoelectric actuator and is formed by this and the at least one first sensor system for determining the deflection is provided from a rest position deflectable probe element. The piezoelectric actuator is attached to a stationary relative to the arc current arranged rigid carrier. Furthermore the monitoring device has a piezoactuator, which cooperates with at least one lever mechanism coupled to the feeler element and having at least one lever.

The disadvantage of the solution found is on the one hand in the relatively high cost of the solution found by a separate sensor and a piezoelectric actuator is used and the loss in the accuracy of measurement, which is connected by the lever and possibly associated with the lever storage game. Especially with very thin papers mechanical and leverage provided monitoring devices have their limits, which is why usually for the scanning and control of very thin papers non-touching measurement methods, such as capacitive measuring methods, proposed and used. In addition, the beats EP 1 172 317 B1 no method for vibration damping before. Vibrations of the measuring system can be caused by impulses that are triggered by the continuous sheet or printed product edges, by the clock movement or by out-of-roundness in the scanning roller. But especially with very thin papers, these vibrations can lead to measurement inaccuracies, which make the use for the detection of very thin paper thickness differences extremely difficult.

The object of the invention is to design a pressing means for a printing press or a print finishing device, the contact pressure is freely selectable and remotely adjustable and can change dynamically during the sheet pass. In addition, the pressing means on possibilities of static and dynamic self-adjustment. The pressing device can also provide a low-vibration timing.

The problem is solved by the features of claim 1 or claim 2.

Meaningful developments emerge from the dependent claims.

The object of the invention is achieved by the pressing means by means of an active spring against the printing substrate or the printed product is displaced or the pressing means itself is formed from an active spring.

Active springs are a composite of a spring material and a piezocomposite film. Active springs can have a wide variety of designs and be designed as sheet-plate or coil springs. Piezo composites are conventional piezoelectric materials, preferably as piezo fibers, which are incorporated in a polymer matrix. The piezofibers and the piezoelectric threads formed therefrom are preferably formed from piezoceramics, which can be integrated very well in a fibrous form into a polymer matrix. The incorporation of the piezo fibers into the polymer matrix once provides protection against mechanical and / or chemical stresses, but also permits use in flexible applications. The piezofibres are optimally protected against breakage by incorporation into the polymer matrix during flexion, since piezo fibers are themselves rather brittle. In a preferred embodiment according to the invention, the piezoactuators are designed as a flexible film which can be adapted to the different contours of the spring elements and permits full-area attachment of the piezocomposite film to the spring material. Piezo composite films offer a high power / volume ratio, low weight and small footprint. This makes it possible to connect these piezocomposites with spring material to an active spring. The switching and control speeds are generally over one kilohertz, so that even during the printing substrate or print product run adjustments of the supplies can be made.

The active springs consist of a composite material formed from the spring steel sheet, for example in a thickness range of 0.1 to 3.0 mm thickness, and a piezocomposite film. With the piezocomposite, the active spring receives a controllable adding bias. The properties of the spring plate are retained and it is possible to initiate an additional bias of the spring regardless of the spring load. By choosing the spring geometry, it allows one Freely selectable ratio of force and distance. Possible changes in length are in a range of up to 20%, so that they can be used in a variety of fields in printing and finishing machines. The performance of the piezocomposite is almost completely absorbed by the spring, almost exclusively bending losses occur.

The advantage of the active springs results from the simple design and the ability to change the bias during the passage of print substrates or printed products.

The invention will be explained in more detail below with reference to drawings.

Figur 1

einen erfindungsgemäßen Aktuator und

Figur 2

eine Bogenzufuhreinrichtung.

Show here

FIG. 1

an actuator according to the invention and

FIG. 2

a sheet feeder.

1 shows a simple embodiment of a pressing means according to the invention is shown. On a spring plate 1, a piezocomposite 2 is glued or fixed in another suitable form. The spring plate 1 has in a preferred embodiment, a hardened bottom 3 and is attached to a bearing 4 at the end. On the opposite side of the composite of spring plate 1 and piezocomposite 2, a pressure roller is attached, for example, to a means of transport, e.g. a transport roller or a conveyor belt is arranged. The pressure roller can be displaced by changing the spring tension through the piezocomposite to or from the transport away.

To those in the patents US 5443257 and EP 1 172 317 B1 There is a clear distinction, since the piezocomposite does not act against a lever mechanism and is not connected to a fixed rigid support, but part a flexible spring. Due to the piezocomposite, the spring receives a controllable addable preload and thus ensures the displacement of the pressing means. In a particular embodiment of the invention, the pressing means is connected directly to the active spring, that is, the spring acts directly on the pressing means. As a result, a highly accurate employment of the pressing means in the simplest design is possible. As a result, the construction is significantly cheaper and the adjustment is passed more precisely to the pressure element, since the active spring acts directly without the need for further lever mechanisms, which are often subject to play. In a further advantageous embodiment of the invention, the pressing means is formed by the active spring itself. Here, the effect on the printing substrate or the printed products is most directly given.

Piezoactuators have the further advantage that they can be used either actively as a piezo actuator or passive as a sensor, in which the voltage is tapped off, which is formed when the piezoelectric element is deformed by a mechanical action. The tappable voltage signal is proportional to the acting force as a pressure sensor or as a displacement sensor proportional to the acting deformation. In order to measure and control the displacement of the pressing means by the action of a piezo actuator, the EP 1 172 317 B1 before the displacement path by means of a separate sensor to measure and control. Although this method allows the design of a control loop, but is too expensive and expensive for itself and complicates the entire structure. The solution according to the invention therefore proposes that the active spring, formed from the spring element which is connected to the piezocomposite film, is simultaneously used as an actuator and as a sensor. Advantageously, therefore actuator and sensor are combined in one component. It is advantageous in the first place that no additional additional component is required as a sensor, resulting in cost and space advantages in the first line.

In a first embodiment of the actuator / sensor principle according to the invention, some piezoceramic fibers of the piezocomposite film are used as actuators, while other piezoceramic fibers are used as sensors. In this case, a large number of active, used in Aktorenmode, operated piezoceramic fibers are compared to a small number of passively operated, used in the sensor mode Piezokermikfasern or vice versa. Since the absolute value of the elongation is rather small, but the associated charge quantities are rather large, in the preferred embodiment a multiplicity of active piezoceramic fibers operated in the actuator mode can face a smaller number of passive piezoceramic fibers operated in the sensor mode. The contacting of the passive and the active fibers to the outside takes place via separate electrodes which allow a reading of the sensor part and a control of the Aktorteils separated from each other.

Alternatively, the spring material can also be covered with two separate piezocomposite films, wherein a piezocomposite film is operated as an actuator and a piezocomposite film as a sensor. This can be done, for example, by gluing, for example, a leaf spring on one side with the Aktoranteil and the opposite side of the leaf spring is glued to the sensor part.

With the simultaneous operation of the active spring as a sensor and actuator, the pressing means can always be made against the printing substrate or the printed product, without causing overpressing. Between actuator and sensor, there is a closed loop with the interposition of a control device. By means of the Aktoranteils of the active spring, the pressing means is in contact with the with the printing substrate or the printed product. In a contact, the spring is pressurized, which is measured by the sensor portion. The contact pressure can then be increased or decreased by a defined amount or maintained at the targeted level. An input or measurement of the sheet thickness can advantageously be completely eliminated. In a preferably applicable embodiment, the sensor signal for measuring the contact pressure is filtered by a low-pass filter, so that only low-frequency sensor signals are used for the evaluation of the contact pressure. As an alternative to filtering by means of a low-pass filter, the evaluation of the be detected by the sensor pulses are limited to the pulses that exceed a certain pulse size as a threshold. This procedure avoids that oscillations of the active sheet guiding or sheet guiding elements in the sense of the invention lead to changes in the setting pressure. Through this active, self-adjusting adjustment of the contact pressure even a shingled sheet flow can be optimally transported without the individual sheets experience too much pressure by the pressing means. At each scale transition, the sensor component receives a large impulse with a directional indication of the deflection, whereby the contactor is displaced in the directional course determined from the pulse progression and the fine adjustment takes place via the control circuit through the actuator component. The determined values can then be learned and used for the further production process by being stored. This approach has clear advantages over the rigid approach of control by default values, as described in the EP 172 317 B1 is used because the individual characteristics, such as paper structure, paper hardness and flexural rigidity are learned by the self-learning algorithm.

In a further embodiment according to the invention not only an adaptation to the different surfaces is performed by the active spring, but also a timing of the pressing means made in the sense that the pressing means completely stands out from the printing substrate surface or printed product surface. Such a timing is useful to avoid jamming or abutment of printing substrate or printed product edges when it is introduced in the gap between the pressing means and transport. After passage, the pressing means can be lowered again on the printing substrate, on the sheet flow formed from printing substrates or on the printed products. This reduction can be done by the control of default values or by the utilization of the previously described control algorithm.

For the adaptation to the printing substrate surfaces and / or the timing of the pressure element can be completely taken over by the active spring.

The active spring or a device with an active spring can therefore be hung directly on a rigid suspension, for example, a rigid cross member. This has the significant advantage that can be completely dispensed with a clocking shaft and the associated drive, as used for example for the suspension of clock rollers in the feeder of a sheetfed press. As a result, for example, a sheet-processing investors can be built significantly cheaper and less expensive.

By means of said apparatus, double sheets can also be detected via the size of the impulse response. If there is more bow or if there is an additional material scrape between the pressing means and the means of transport or if there is another fault that changes the distance between the pressing means, this can be measured via the sensor portion. With a simultaneous intake of more sheets than intended, the impulse response is greater than expected, or in the case of another disturbance, for example a paper shred, the disturbance comes at an unexpected time. Both extraordinary events can be detected and identified, for example, by exceeding threshold values. If such a double sheet occurs or a fault is identified, the printing or further processing device can be stopped in order to avoid damage to the machine in the subsequent processing steps.

The great advantage of the simultaneous use of the device according to the invention as a control roller and as a double-sheet device is that the feeder of a sheet-processing printing or further processing machine can be significantly simplified. Currently, such investors typically have separate clock rolls and multiple sheet monitoring devices. Through this combination of both functions, the transport function of the control roller and the monitoring function of the multiple sheet control device, in a unit, there is a significant cost reduction. In addition, the operation of such an investor is significantly simplified because the user adjust at most one device and may or may not have to do without intelligent control or regulation functions.

If more than two devices according to the invention are arranged across the width of the machine, it is also possible to detect early, late or oblique curves and to derive corresponding machine actions. The detection can be done by adjusting the timing of the impulse response of the sensor portion of the piezo actuator with the predetermined target times. If the impulse occurs earlier than the target time, it is an early arch, if later it is a late arch and if it occurs unevenly on both devices, this is a slanted arch.

By the clock movement and / or the change in distance by a scale flow and / or by vibrations resulting from other components and / or inaccuracies in the pressure element, for example, the out-of-roundness of a pressure roller and / or by the surface structure of the printing substrate or the printed product vibrations in the system can be induced, which can at least make the measurement of small paper thickness impossible. One approach to countering this would be to carry out the suspension system for the pressure system as stable as possible. The separation of the piezo actuator into an actuator and a sensor component also makes it possible to actively prevent these vibrations by filtering the impulse responses supplied by the sensor component of the piezoactuator, for example by a high-pass filter, and by feedback to opposite actuations of the actuator component. This actively combats higher-frequency or high-frequency vibrations. This has the significant advantage that the spring and / or the suspension device for the pressure element does not have to be designed so massive. A lighter design improves the system's response time, since less mass has to be moved, but also leads to the positive effect of cost savings. However, such active damping is also possible if the deflection of the suspension is measured by means of another suitable measuring system.

As shown in FIG. 2, one or more sheet guiding devices (5) or sheet guiding devices (5) according to the invention can be arranged above the transport roller (6) of an investor. The sheet is lifted from the suction head of the feeder (11) of the stack (10) and inserted between the sheet guiding device according to the invention (5) and the transport roller (5).

FIG. 2 further shows that one or more sheet guiding devices (5) according to the invention can be arranged at one or more locations on the feeder table (8) of a sheet-fed printing machine.

The invention further comprises a sheet guiding device in the region of the application sheet of a sheet-leading printing press, which is arranged above the bearing plate transversely to the sheet running direction and is clockably movable up and down. The sheet guiding device can be designed as a roller, bar or brush strip. In such a sheet guiding device timing or a permanent adjustment of the contact pressure is useful because otherwise the separation between the peeling sheet and the incoming sheet is difficult, because at a continuous sheet guiding device, the underlying subsequent sheet can be partially or over the entire width of the Pulling bow with pulled up. For very rigid sheets, the pressure on the substrate can also be very large, because by the deflection in the sheet transfer by the pre-gripper of a sheet-leading press presses the sheet at the end increasingly against the rigid sheet guiding device. For pressure-sensitive substrates, such as corrugated or plastic films, the surface may be damaged if under pressure. The operator tries to avoid damage by setting the sheet guiding device higher, but this makes the advantageous effect of the sheet guiding device in the threading of the incoming sheet into the deck marks of the printing machine difficult or even impossible. This can be avoided by the sheet guiding device is lowered clocking, ie the sheet guiding means is lowered by a certain amount when a new sheet in the contact area of the printing press arrives and raises again by a defined amount when the sheet is pulled into the press. According to the invention, this clocking of the sheet guiding element is initiated by one or more active springs or the sheet guiding element is formed by an active spring itself. Compared to the known mechanical timing solutions, the user can remotely adjust the lower point and the upper point, or both can be set based on default values derived, for example, from the thickness of the film. Another advantage is also that you can work with the active vibration damping, ie the sheet guide element can be designed much easier. In the clocking therefore lower masses must be moved, whereby the dynamics of the clocking can be significantly improved.

In a particular embodiment of the invention, the contact pressure of the sheet guiding element is detected via the sensor portion of the active spring and is kept constant in a control loop of the pressure exerted on the substrate by controlling the Aktoranteils active spring within certain tolerance limits. This solution found offers an advantageous application especially in the processing of flexurally rigid substrates in sheetfed presses. Regardless of the flexural rigidity, format and print speed, there is always just enough pressure to ensure that the sheet is guided. When the outgoing bow is fully retracted, the pressure exerted by the outgoing bow falls away and the active spring lowers the bow guide member, thereby ensuring good insertion of the incoming bow into the deck marks.

The invention further comprises a sheet guiding element according to the invention, which is arranged above the side mark of a sheet-fed printing press. For a new incoming sheet, the sheet guiding member is lifted by means of an active spring and lowered during the side pulling operation. This ensures a safe side pull even on wavy substrates.

The invention also includes one or more active sheet guiding elements which fix a sheet or roller conveyor leading cylinder of a printing or finishing machine by applying a contact pressure, wherein the contact pressure can be varied by the active spring. In an extension, the active spring optionally initiates a clock movement. This may be necessary, for example, in a sheet-guiding machine in which the sheets are fixed by means of grippers on the cylinder. Due to the active spring, the sheet guiding element can always be raised when the grippers pass under it.

Claims (26)

A pressing means for fixing a sheet, a sheet stream, formed of a plurality of successive sheets, a roller conveyor, a printed product or a printed product stream, formed from a plurality of successive printed products, under pressure on a conveyor, wherein the conveying means is a transport cylinder of a sheet-fed, web-fed printing press or copying machine, a conveyor belt of a printing, copying or a further processing machine or a collecting cylinder of a copying or further processing machine and the pressing means is a pressure roller, a hold-down plate, a hold-down rod, a brush, a brush strip or a roller,
characterized,
in that the pressing means (5) are formed by one or more active springs, formed from a composite of a spring material (3) and one or more piezoactuators (2), or by a pressing means, which itself is formed by an active spring, in the direction of the conveying means (6, 7, 8, 9) or away from it by the piezoelectric actuator (2) as part of the active spring, is arranged to be displaceable. Monitoring device for the sheet feed to a sheet-processing machine, in particular sheet-fed printing machine, with at least one arranged above or below the arc current probe element which is displaceable towards the arc current and in the opposite direction, the probe touches the arc current only in case of error,
characterized,
that the feeler element (5) by means of an active spring, formed of a composite of a spring material (3) and one or more piezoactuators (2) against the arc current or away from this, or that the probe element (5) itself from an active Spring is formed. Pressing means according to claim 1 or monitoring device according to claim 2,
characterized,
in that the one or more piezoactuators (2) of the active spring are formed from a flexible piezocomposite film which is in a firm bond with the spring material (3). Pressing means according to claim 1 or monitoring device according to claim 2,
characterized,
in that an additional summable prestress can be impressed by the piezoactuator (2) of the active spring. Pressing means according to claim 1 or monitoring device according to claim 2,
characterized,
that the active spring or the active springs are designed as a leaf, plate or coil spring. Pressing means according to claim 1 and 5 or monitoring device according to claim 2 and 5,
characterized,
that the spring material (3), from which the active or active springs are formed of a spring sheet having a thickness of 0.1 - 3.0 mm thickness is formed. Pressing means according to claim 1 or monitoring device according to claim 2,
characterized,
in that the piezoactuator (2) on the active spring or the active spring itself is operated simultaneously or alternately as an actuator for force and / or path generation and / or as a sensor for measuring force and / or distance. Pressing means or monitoring device according to claim 7,
characterized,
that the sensor and the Aktoranteil of the piezo actuator (2) are combined in one component. Pressing means or monitoring device according to claim 8,
characterized,
that the sensor and the Aktoranteil of the piezo actuator (2) are formed of respectively separate piezo ceramic fibers combined in a Piezokompositfolie. Pressing means or monitoring device according to claim 9,
characterized,
that a smaller number of the piezoelectric ceramic fibers as a sensor and a large-βere number of piezo-ceramic fibers as Aktoranteil of the piezo actuator (2) are provided in the Piezokompositfolie. Pressing means or monitoring device according to claim 8,
characterized,
that the sensor and the Aktoranteil of the piezo actuator (2) are each formed from a Piezokompositfolie and are united with the spring material (3). Pressing means or monitoring device according to claim 7 to 11,
characterized,
in that a control device is provided in connection with the sensor and the actuator portion of the piezoactuator (2), to which signals from the sensor portion of the piezoactuator can be supplied, and control signals can be generated by means of the control apparatus, which control signals can be generated by the actuator portion of the piezoactuator and / or a force acting on or in connection with a probe element (5) are zuluhrbar. Pressing means or monitoring device according to claim 1 to 12,
characterized,
in that a control device is provided in connection with a piezoactuator (2) acting as a sensor, to which a filter device is assigned, to which signals of the sensor can be fed and by means of which vibrations transmitted from the guide or transport elements for the sheet transport can be filtered out of the signals of the sensor , Pressing means or monitoring device according to claim 13,
characterized,
in that a control device is provided in connection with a piezoactuator (2) acting as a sensor, to which a filter device can be supplied and signals of the sensor can be detected and by means of which vibrations transmitted from the guide or transport elements for the sheet transport can be detected from the signals of the sensor, and that by means of the control device to the piezoelectric actuator (2) actuating signals for damping of high-frequency vibrations are zuleitbar. Pressing means or monitoring device according to claim 1 to 14,
characterized,
in that a control device is provided in connection with a piezoactuator (2) acting as a sensor, to which a control device can be supplied, to which signals of the sensor can be fed and by means of which lower and / or upper threshold values for the pulse size of signals to be relayed are used by the control system. or transport elements for the sheet transport vibrations transmitted to the sensor are adjustable. Pressing means or monitoring device according to claim 12 to 15,
characterized,
in that the regulating and / or control device is associated with memory devices, that values of the signal and / or pulse progression of the sensors and / or actuators can be stored and that the values for controlling and / or monitoring the sensor function and / or the actuator function of the piezoactuators (2 ) are available for sheet transport. Pressing means or monitoring device according to claim 12 to 16,
characterized in that in conjunction with the piezoelectric actuator (2) by means of the control and / or control device values of the signal and / or Lmpulsverlaufes the actuators are generated such that due to the measured values of the sensors on the leading from the actuators Bow exercisable force is kept constant within tolerance limits. Pressing means or monitoring device according to claim 17,
characterized in that the pressing means (5) are provided in connection with guide elements (5) for guiding sheets in the area of the sheet feeder of a sheet-fed printing machine, in particular during the supply to the sheet-fed printing press. Pressing means or monitoring device according to claim 1 to 17,
characterized,
in that the pressing means (5) are provided in connection with guide elements (5) for guiding sheets in the region of a side mark for side edge alignment of sheets when fed to a sheet-fed printing machine. Pressing means or monitoring device according to claim 19,
characterized in that the pressing means (5) are arranged in the region of a side mark in the supply of sheets from the guide surface of the sheet and / or the sheet surface liftable. Pressing means or monitoring device according to claim 1 to 17,
characterized,
in that the pressure means (5) are provided in the region of a guide of printing material by a sheet-fed or web-fed printing press to guide the cylinder surfaces leading to the printing material, such that the printing material can be applied force-controlled to the cylinder surfaces. Pressing means or monitoring device according to claim 21,
characterized,
that the pressure means (5) in the region of an interruption of the cylindrical surfaces of the surface of the print substrate are arranged be lifted off. Pressing means according to Claims 1 and 3 to 22 or monitoring device according to Claims 2 to 22,
characterized,
in that the pressing means (5) are constructed as a feeler element which can be applied against the printing material sheets or webs to be guided and / or scanned by means of the active spring connected to or even formed by a piezoactuator (2). Pressing means or monitoring device according to claim 23,
characterized,
in that the pressing means (5) is associated with a conveyor table (8) for transporting a submerged sheet flow in a working cycle to a sheet-processing machine and that the pressing means (5) for monitoring the relative position of the sheet with respect to their transport path to the sheet-processing machine and / or is provided for monitoring the stratification of the underlying lying bow. Pressing means or monitoring device according to claim 23,
characterized,
in that the pressing means (5) is associated with a conveyor roller (9) of a conveyor table (8) for transporting a submerged sheet flow in a working cycle to a sheet-processing machine and that the pressing means (5) for monitoring the lamination of the underlying sheets and / or for ensuring the conveyance of the sheets separated by a sheet stack (10) provided in an arch feeder to the conveyor table (8) and / or for deflecting the sheet fed from the sheet stack (10) in an approximately horizontal plane into one in the region of the conveyor roller ( 9) sloping sheet-processing machine leading level of the conveyor table (8) is provided. Pressing means or monitoring device according to claim 23,
characterized,
in that the pressing means (5) are associated with a conveying roller (6) which is associated with a sheet stack (10) of a sheet feeder (8) for conveying sheet separated from the sheet stack (10) to a sheet flow underfed in one working cycle to a sheet-processing machine and that the pressing means (5) for monitoring the stratification of the underlying sheets and / or to ensure the further promotion of a sheet stack (10) isolated sheet to the conveyor table (8) and / or to monitor the relative position of the arc with respect to the Transport path and / or conveying cycle is provided for sheet processing machine.

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