DE102019122494B4 - Device for feeding sheets - Google Patents

Abstract

Device for feeding sheets, with a sheet separator (7) for separating the sheets cyclically from a stack and with suction cups for transporting the sheets to a belt table (2), the belt table (2) having a transport level and at least one circulating conveyor belt (14) comprises, wherein a section of the at least one conveyor belt (14) is guided over at least two upper belt rollers (12.1, 12.2) in the transport plane and at least one further belt roller (12.3, 12.4, 12.5) is formed which supports the at least one conveyor belt (14 ) leads outside the transport plane, the at least one further belt roller (12.3, 12.4, 12.5) being assigned a first drive (25) and the section of the at least one transport belt (14) guided in the transport plane forming a load strand (14.1) and between the Conveyor suction devices and the at least one conveyor belt (14) have a curved flap connected to a pivotably mounted shaft A second drive (24) pivoting this is assigned to the shaft and a main stack carrier for carrying a main stack and an auxiliary stack carrier for carrying an auxiliary stack is formed, the main stack carrier being assigned a vertically displacing third drive (22) and the auxiliary stack carrier being assigned a third drive vertically displacing fourth drive is assigned and the sheet separator (7) and / or the transport suction devices is assigned a fifth drive (23) which drives the sheet separator (7) and / or the transport suction devices independently of the first drive (25) and wherein the drives ( 25, 24, 22, 23) can be controlled independently of one another.

Description

The invention relates to a device for feeding sheets, with a sheet separator for separating the sheets in cycles from a stack and with suction cups for transporting the sheets to a belt table. Such devices are used in particular in connection with sheet processing machines or as part of sheet processing machines. In connection with uses in sheet processing machines that are designed as printing machines, they are also referred to as feeders.

From the DE 102 16 135 A1 a method for controlling the sheet feed to a sheet processing machine with a sheet feeder is known which has, inter alia, a sheet separator for separating the sheets from a stack and a belt table or suction belt table. The sheets are transported to the machine and checked for double, missing or skewed sheets. If such a sheet is present or if there is a malfunction in the downstream machine, the sheet feed is stopped, with a scanning device detecting the height of the stack being provided and the sheet feeder being driven by individual drives that are operated by means of processing electronics that are linked to a control device of the downstream machine is to be controlled

In the EP 1 281 647 B1 a method for conveying sheets in a sheet feeder of a sheet processing machine is presented. In the sheet processing machine, the running speed of the conveyor belt for conveying the shingled sheets can be changed independently of the operating speed of the machine in accordance with predetermined speed profiles.

Through the DE 10 2007 051 945 A1 a feeder is known which comprises several components for influencing the sheet, which are assigned drives that can be controlled independently of one another. The components include a sheet separator, which is used to separate the sheets from a stack of sheets, a suction belt table, which is used to transport the sheets in scaled form, and a flap shaft. Each of the components has an individual drive.

In the drive arrangements of the known suction belt tables, the empty run of the suction belts used lies on the sheet-transporting table surface, while the load run is on the underside of the belt table. The suction belts and the sheet relay resting on them are pushed, which has a detrimental effect on the conveying accuracy.

the DE 10 2012 211 784 A1 discloses a conveying device for conveying sheets of printing material in a painting and / or printing machine. The conveying device has a circulating means by means of which a sheet of printing material can be moved against a stop surface of a stop device provided downstream, with the formation of a form fit or frictional connection.

the EP 1 281 647 B1 describes a method for conveying sheets in a feeder of a sheet processing machine. The feeder is equipped with a conveyor belt which conveys a shingled sequence of sheets in the area between a sheet pile and the front stops of the machine.

From the DE 102 16 135 A1 a method for controlling the sheet feed to a sheet processing machine with a sheet feeder is known. The sheet feeder has a sheet separator for separating the sheets from a stack and timing rollers for transporting the separated sheets in one transport direction to a conveyor table. The belt table comprises a driven drive roller wrapped around by a suction belt and a deflection roller. A suction box is provided between the drive roller and the deflection roller.

Subject of DE 10 2007 051 945 A1 is a method of controlling the feeding of sheets to a sheet-fed press with a multi-component sheet feeder. One of the components is formed by a suction belt table.

From the DE 10 2018 201 918 A1 a sheet-fed printing machine with a substrate feed device is known. The substrate supply device comprises a suction belt table.

The invention is based on the object of creating a device for feeding sheets in which the sheets are transported with greater accuracy, in particular with greater uniformity.

The object is achieved according to the invention by the features of claim 1.

The advantages that can be achieved with the invention are, in particular, that fluctuations in the distances between the sheets in the sheet relay are reduced and the sheet arrival for each individual sheet at the end of the transport path of the suction belt table can be realized exactly at the specified time.

Embodiments of the invention are shown in the drawings and are described in more detail below.

• 1 Eine Vorrichtung zum Zuführen von Bogen mit einem Saugbandtisch.
• 2 Eine detaillierte Seitenansicht des Saugbandtisches.
• 3 Eine schematische Darstellung einer als Pendelwalze ausgebildeten Bänderwalze.

Show it:

• 1 A device for feeding sheets with a suction belt table.
• 2 A detailed side view of the suction belt table.
• 3 A schematic representation of a belt roller designed as a pendulum roller.

The device for feeding sheets can be used as a feeder 1 a sheet-processing machine, in particular a sheet-fed printing machine or a punching machine, and will be described below using this example.

The device for feeding sheets, in particular the feeder 1 , preferably comprises a main stack carrier, in particular a stacking plate, on which a stack consisting of the sheets can be positioned. The stacking plate is attached to means of transport.

At the rear and on the sides of the stack, blowers can be provided for loosening the sheets on the stack and for blowing under the sheets during transport. In order to be able to form an air cushion carrying the sheets, side plates or guide elements laterally delimiting the stack can additionally be arranged on the side of the stack.

There is a sheet separator near the top of the stack 7th arranged.

The bow separator 7th preferably has separating suction cups and transport suction cups. The bow separator 7th is preferably height adjustable in the feeder 1 arranged. In addition, the sheet separator 7th for format adjustment in or against a transport direction 11 be slidably mounted. The bow separator 7th , in particular its separating suction device, is used for the cyclic separation of the sheets from the stack, the transport suction device grasping the separated sheets and moving them in the direction of transport 11 promotes. A scanning device which detects the height of the stack can be arranged in the stack area. The transport suction device transports the sheets to a conveyor table 2 . The belt table 2 has a transport plane in which the sheets of at least one circulating conveyor belt 14th be transported. A section of the at least one conveyor belt is preferably in each case 14th over at least two upper belt rollers 12.1 , 12.2 guided in the transport level. Next to the upper belt rollers 12.1 , 12.2 is at least one further belt roller 12.3 , 12.4 , 12.5 formed that the at least one conveyor belt 14th outside, especially below the transport level. The at least one further belt roller 12.3 , 12.4 , 12.5 is a first drive 25th assigned, so that the section of the at least one conveyor belt guided in the transport plane 14th the load strand 14.1 of the conveyor belt 14th forms. The section of the at least one conveyor belt that is guided outside the transport plane 14th forms the empty run 14.2 of the at least one conveyor belt 14th .

The first drive 25th is preferably used as a motor 25.2 educated. The first drive 25th can be directly on the axis of another belt roller 12.3 , 12.4 , 12.5 be assigned or via a gear pair or a belt drive, in particular a toothed belt drive with the further belt roller 12.3 , 12.4 , 12.5 be connected in terms of transmission technology. Outside, in particular below the transport level, two or three further belt rollers can also be used 12.3 , 12.4 , 12.5 be arranged over which the at least one conveyor belt 14th is performed, the first drive 25th in the case of three further belt rollers 12.3 , 12.4 , 12.5 the middle of the three other belt rollers 12.3 , 12.4 , 12.5 can be assigned. In the case of the formation of several further belt rollers 12.3 , 12.4 , 12.5 over which the at least one conveyor belt 14th is performed, the first drive 25th alternatively that of the other belt rollers 12.3 , 12.4 , 12.5 be assigned the furthest from the arch separator 7th is spaced.

On the sheet transporting side of the belt table 2 is the conveyor belt 14th consequently designed as a pulling band. This has the advantage that it is on the conveyor belt 2 As a sheet relay, sheets lying down can be transported more calmly and evenly, so that there are fewer disruptions.

The diameter of the belt rollers 12.1 , 12.2 , 12.3 , 12.4 , 12.5 can be of different sizes. The diameter of that belt roller is preferably 12.3 , 12.4 , 12.5 who is the first drive 25th is assigned, larger than the diameter of the upper belt rollers 12.1 , 12.2 .

One of the further belt rollers is preferably one 12.3 , 12.4 , 12.5 assigned a tensioning device with which the respective further belt roller 12.3 , 12.4 , 12.5 to change the tension of the at least one conveyor belt 14th can be displaced with respect to this and can be fixed in the displaced position. The tensioning device can also comprise an energy store, in particular a spring system, the spring force of which is adjustable, and the one of the further belt rollers 12.3 , 12.4 , 12.5 resilient against the conveyor belt 14th tense.

Preferably at least one of the belt rollers is 12.1 , 12.2 , 12.3 , 12.4 , 12.5 , in particular one of the other belt rollers 12.3 , 12.4 , 12.5 designed as a pendulum roller. A belt roller designed in this way 12.1 , 12.2 , 12.3 , 12.4 , 12.5 has a corrective belt guiding function, especially when force and / or load changes in or on the conveyor belt 14th appear. The belt roller designed as a pendulum roller 12.1 , 12.2 , 12.3 , 12.4 , 12.5 has two degrees of freedom and automatically corrects tape tracking errors. The formation of a belt roller 12.1 , 12.2 , 12.3 , 12.4 , 12.5 as a pendulum roller enables both a tilting movement of the same transversely to the transport direction 11 as well as a rotary movement in the transport direction 11 .

The pendulum roller comprises a fixed axle 26th and one coaxial with the axis 26th around the axis 26th rotatably arranged, hollow cylinder-shaped roller body 27 . Between the axis 26th and the roller body 27 acts a self-aligning bearing 28 . The self-aligning bearing 28 can be designed as a self-aligning ball bearing or as a spherical roller bearing or in another suitable form. The self-aligning bearing 28 is preferably in the middle between the two ends of the roller body 27 arranged so that the center of mass of the roller body 27 above the self-aligning bearing 28 lies and the roller body 27 in relation to the self-aligning bearing 28 is balanced.

The self-aligning bearing 28 can one with the roller body 27 connected outer ring 29 and one with the axis 26th connected inner ring 30th exhibit. The outer ring 29 is opposite the inner ring 30th by two rows of balls spaced from one another 31.1 , 31.2 or rows of roles 31.1 , 31.2 supported. On the outer ring 29 and / or on the inner ring 30th is preferred for both rows of balls 31.1 , 31.2 or rows of roles 31.1 , 31.2 a common hollow spherical raceway is formed. The belt roller preferably has 12.1 , 12.2 , 12.3 , 12.4 , 12.5 , especially the other belt roller 12.3 , 12.4 , 12.5 who is the first drive 25th is assigned a spherical shape, while all other belt roller 12.1 , 12.2 , 12.3 , 12.4 , 12.5 may be formed with a cylindrical shape. The belt roller designed with a spherical shape and acting as a drive roller 12.1 , 12.2 , 12.3 , 12.4 , 12.5 takes on a centering function in the system in addition to the driving function. The belt roller is accordingly 12.1 , 12.2 , 12.3 , 12.4 , 12.5 who is the first drive 25th is assigned, preferably different from the belt roller 12.1 , 12.2 , 12.3 , 12.4 , 12.5 , which is designed as a pendulum roller.

In a preferred embodiment of the device with two or three further belt rollers 12.3 , 12.4 , 12.5 that are below the transport level of the conveyor table 2 are arranged, the first drive 25th either one of the two or the middle of the three further belt rollers 12.3 , 12.4 , 12.5 be assigned, with another further belt roller 12.3 , 12.4 , 12.5 is designed as a pendulum roller.

Instead of a single conveyor belt 14th can also use two or more spaced apart over upper belt rollers 12.1 , 12.2 and further belt rollers 12.3 , 12.4 , 12.5 guided conveyor belts 14th be provided.

Preferably the conveyor belts are 14th designed as suction bands and have openings. The suction belts are preferably supplied with suction air from suction boxes, which are fed into the belt table 2 can be integrated. As a result of the effect of the suction air, sheets to be transported are placed on a conveyor belt designed as a suction belt 14th held.

The belt table 2 A feed table with front lays, a system and a processing plant can be arranged downstream of a sheet processing machine. The processing unit is preferably an offset printing unit, a coating unit, an inkjet printing unit or a punching unit.

Between the suction cups and the at least one conveyor belt 14th of the belt table 2 a curved flap connected to a pivotably mounted shaft is formed. The functional unit consisting of a shaft and a curved flap is also referred to in technical terms as a flap shaft. The flap shaft extends across the width of the stack. For each sheet to be conveyed, the sheet flap is pivoted from a vertical position in which it forms a stop to a horizontal position in which it forms a guide surface.

With the at least one conveyor belt 14th of the belt table 2 So-called timing rollers preferably work together. The timing rollers can be assigned to a pivotably mounted timing roller shaft which is pivoted in time with the sheet sequence, so that the timing rollers move the front area of each sheet against the at least one conveyor belt 14th of the belt table 2 to lead.

In order to drive the components causing the sheet transport, several individual drives are preferably provided, which can be controlled independently of one another. In addition to that of a belt roller 12.1 , 12.2 , 12.3 , 12.4 , 12.5 assigned first drive 25th can be a second drive 24 be formed, which is assigned to the shaft carrying the arched flap. The second drive 24 can also be designed to jointly drive the timing roller shaft and the shaft connected to the sheet flap. The timing roller shaft and / or the shaft connected to the curved flap are preferably connected to the second drive via a gear unit 24 tied together.

A third drive can also be used 22nd be assigned to the main stack carrier for its vertical displacement. In the case of the formation of a non-stop device, the main pile carrier interacts with an auxiliary pile carrier when the pile is changed, which auxiliary pile carrier can be configured as a rake or roller blind and which is preferably assigned a fourth drive for its vertical displacement.

For driving the sheet cutter 7th and / or the transport suction device can have a fifth drive 23 be trained.

To detect the arrival of the sheets, a sheet arrival sensor can be designed, which is preferably at the end of the belt table 2 is arranged. With the sheet arrival sensor, the position of the sheets at a specific point in time can be detected before the sheets enter the processing unit. The sheet arrival sensor generates first signals representing the arrival of the sheets for a sequence of sheets. To detect the angular position of the at least one processing unit, a clock generator is designed which generates second signals representing the angular position of the at least one processing unit.

The feeding of sheets to the at least one processing unit is only possible if the at least one processing unit, in particular its sheet-guiding cylinder, is in a certain angular position. To achieve this, the individual drives must 22nd , 23 , 24 , 25th be controlled accordingly.

The drives 22nd , 23 , 24 , 25th as well as the clock generator and sheet arrival sensor are connected to a controller.

The controller preferably controls the first drive 25th another belt roller 12.3 , 12.4 , 12.5 as a function of the signals of the clock generator, in particular the second signals. In other words, the movement of the conveyor belt or belts follows 14th of the belt table 2 excluding the movement of the at least one processing plant. The second drive 24 becomes the first drive differently from the control 25th controlled not only according to the second signals from the clock generator but also according to the first signals from the sheet arrival sensor.

The controller can control the first and the second drive 25th , 24 each cycle-related speed profile must be entered. The speed profiles can have a discontinuous speed profile.

The controller preferably determines the phase positions of the first signals in relation to the phase positions of the second signals and controls the second drive 24 as a function of the determined phase positions of the first signals in relation to the phase positions of the second signals. In this way, conclusions can be drawn about the occurrence of sheets arriving too early (early sheets) or the occurrence of sheets arriving too late (late sheets) and appropriate countermeasures can be taken.

The control is in particular such for controlling the second drive 24 designed that, depending on the phase positions of the first signals in relation to the phase positions of the second signals, the phase positions of the speed profile of the second drive 24 to the phase positions of the speed profile of the first drive 25th leading or lagging or the second drive 24 drives with a speed profile that has an increased or a decreased average speed.

If, for example, a late arc is detected by determining the phase positions, this can be done by increasing the speed of the fifth drive 23 of the arch separator 7th and / or the transport suction device and by an increased speed of the second drive 24 be effected on the sheet flap opposite the conveyor belt14 that the sheet leading edge of subsequent sheets arrives earlier at the processing plant. The length of the scales between the arches is reduced.

The control can react to an early arc in the same way, with the difference that the speed of the fifth drive 23 and the second drive 24 is decreased and the scale length, that is, the distance between the leading edges of the sheets, is increased.

It is also possible to provide several sheet arrival sensors that monitor the sheets. The invention is not limited to the exemplary embodiment described above. Other components of the investor equipped with drives, not mentioned in the exemplary embodiment, could also be used 1 be provided.

List of reference symbols

1

Investors

2

Belt table

7th

Arch separator

11

Transport direction

12.1

upper belt roller

12.2

upper belt roller

12.3

another belt roller

12.4

another belt roller

12.5

another belt roller

14th

Conveyor belt

14.1

Load strand

14.2

Empty run

22nd

third drive

23

fifth drive

24

second drive

25th

first drive

25.2

engine

26th

axis

27

Roller body

28

Self-aligning bearings

29

Outer ring

30th

Inner ring

31.1

Row of balls, row of rollers

31.2

Row of balls, row of rollers

Claims (8)

Device for feeding sheets, with a sheet separator (7) for separating the sheets cyclically from a stack and with suction cups for transporting the sheets to a belt table (2), the belt table (2) having a transport level and at least one circulating conveyor belt (14) comprises, wherein a section of the at least one conveyor belt (14) is guided over at least two upper belt rollers (12.1, 12.2) in the transport plane and at least one further belt roller (12.3, 12.4, 12.5) is formed which supports the at least one conveyor belt (14 ) leads outside the transport plane, the at least one further belt roller (12.3, 12.4, 12.5) being assigned a first drive (25) and the section of the at least one transport belt (14) guided in the transport plane forming a load strand (14.1) and between the Conveyor suction devices and the at least one conveyor belt (14) have a curved flap connected to a pivotably mounted shaft A second drive (24) pivoting this is assigned to the shaft and a main stack carrier for carrying a main stack and an auxiliary stack carrier for carrying an auxiliary stack is formed, the main stack carrier being assigned a vertically displacing third drive (22) and the auxiliary stack carrier being assigned a third drive vertically displacing fourth drive is assigned and the sheet separator (7) and / or the transport suction devices is assigned a fifth drive (23) which drives the sheet separator (7) and / or the transport suction devices independently of the first drive (25) and wherein the drives ( 25, 24, 22, 23) can be controlled independently of one another. Device for feeding sheets after Claim 1 , characterized in that three further belt rollers (12.3, 12.4, 12.5) are arranged below the transport plane, over which the at least one conveyor belt (14) is guided, the first drive (25) of the middle of the three further belt rollers (12.3, 12.4 , 12.5). Device for feeding sheets after Claim 1 or 2 , characterized in that several further belt rollers (12.3, 12.4, 12.5) are arranged below the transport plane, over which the at least one conveyor belt (14) is guided, the first drive (25) of that of the further belt rollers (12.3, 12.4, 12.5 ) is assigned, which is most distant from the sheet separator (7). Device for feeding sheets after Claim 1 , 2 or 3 , characterized in that the diameter of the further belt roller (12.3, 12.4, 12.5) to which the first drive (25) is assigned is greater than the diameter of the upper belt rollers (12.1, 12.2). Device for feeding sheets after Claim 1 , 2 , 3 or 4th , characterized in that two spaced apart conveyor belts (14) guided over the upper belt rollers (12.1, 12.2) and the at least one further belt roller (12.3, 12.4, 12.5) are provided. Device for feeding sheets after Claim 1 , 2 , 3 , 4th or 5 , characterized in that a pivotably mounted, timing roller bearing timing roller shaft is formed, the timing roller shaft being assigned a second drive (24) pivoting this, which drives the timing roller shaft and a shaft connected to a curved flap. Device for feeding sheets after Claim 1 , 2 , 3 , 4th , 5 or 6th , characterized in that one of the further belt rollers (12.3, 12.4, 12.5) is assigned a tensioning device with which the respective further belt roller (12.3, 12.4, 12.5) can be displaced in relation to this to change the tension of the at least one conveyor belt (14) and in the relocated position can be fixed. Device for feeding sheets after Claim 1 , 2 , 3 , 4th , 5 , 6th or 7th , wherein the at least one conveyor belt (14) is designed as a suction belt and has openings which are supplied with suction air from a suction box integrated in the belt table (2).

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