EP1338539B1 - Folding device of a printing machine for handling webs with a transport belt monitoring device - Google Patents

Description

The invention relates to a folding apparatus with at least one conveyor belt, which serves for conveying signatures at least on a partial section of a path of the signatures by the folding apparatus.

In a folder separated from a printing sheet sheets or copies are folded and designed to signatures. Typical folders have a variety of processing devices for creating folds, perforations, grooves, cuts and the like. Often, folders have a number of ways along which the processing devices are located and the signatures are transported. Often transport facilities are designed as conveyor belts. Depending on the final product to be produced or the type of fold can be switched between the different ways. To simplify the speech even a separate sheet or a separate copy is already called a signature.

Folders entail, due to the complex sequence of operations performed on the signature, a multiplicity of error sources for damage to the signatures or for production loss, in particular also when setting up the folder in a new configuration for a final print product to be created fold type. Therefore, in typical prior art folders, it is envisioned to provide monitors for transporting signatures along the various paths to detect paper jams and paper misfeeds.

For example, in EP 1 069 062 A2, a paper path monitoring device is provided in a folder, by which misdirected signatures are detected and a shutdown of the folder drive can be triggered. Along the Paths of the signatures through the folder are arranged sensors, which are evaluated on the basis of the signature progression. The sensors are preferably sensor pairs, ie transmitters and receivers, between which the path of the specimens extends.

It has been found that a major cause of production failure in the folder is the unexpected breakage of conveyor belts subject to severe wear. While heretofore monitoring devices concentrate on the paper path per se, especially for setting the folder, or detect paper jams or paper misfeeds after a problem has occurred, so far no information is available about the condition of the conveyor belts in the folder during setup or ongoing production of the machine control made available. Normal wear, unexpected breaks, and unfortunate overstretching due to a paper jam or emergency stop of the machine, or even the disappearance of a conveyor belt due to exceeding its life, are typically detected only when the operator is visually inspecting the folder by the machine operator at standstill. Furthermore, a poor quality condition of the conveyor belts even before a break lead to damage to the signatures.

The object of the present invention is to provide a folder which has less downtime due to unexpected breakage of conveyor belts.

This object is achieved by a device with the features of claim 1 and a method having the features of claim 9. Advantageous developments of the invention are characterized in the subclaims.

According to the invention, information about the quality status of a conveyor belt is to be obtained preventively, ie before an unexpected break occurs. This is indicated by a A folding device according to the invention with at least one conveyor belt which serves to convey signatures at least on a partial section of a path of the signatures by the folding apparatus, at least one monitoring device to which the conveyor belt is assigned, wherein the monitoring device comprises a detector for radiation scattered by at least part of the conveyor belt during at least one period of time.

The radiation may be electromagnetic radiation, in particular visible or infrared light, preferably laser light, or ultrasound.

By means of the monitoring device it can be detected whether a breakage of a conveyor belt is likely to occur. An exchange can then be made before it comes to the unexpected breakage of a worn conveyor belt, especially when the quality state of the conveyor belt for a flawless production is no longer good enough. A folder according to the invention consequently has less downtime due to unexpected breakage of a conveyor belt than a folder without a monitoring device according to the invention.

The monitoring device thus has at least two different functions: on the one hand, the presence, on the other hand, the quality state of the conveyor belt can be determined. In other words, in addition to the function of fracture detection and information about the wear of the conveyor belt can be obtained, so that it can be decided when an exchange of the conveyor belt appears necessary. A timely replacement of the conveyor belt reduces the risk of unexpected breakage.

According to the invention, a method is carried out for monitoring at least one conveyor belt in a folder with the following steps. Radiation scattered from at least part of the conveyor belt at least during a period of time is detected. A signal is generated which is representative of the state of the conveyor belt, in particular for the presence state and / or the Quality condition. The signal is assigned to a condition class. At least two presence assessment classes are required to discriminate presence and absence. The quality status classes are subclasses of the presence class of existence. There can be a number of quality status classes. Typically, two or three classes appear to be useful for assessing quality in order to distinguish a sufficient one from a non-sufficient quality, possibly with a third class of almost sufficient quality. The state class assignment can be carried out in an evaluation unit or in a machine control according to predetermined criteria via the conveyor belt parameters.

In a particularly advantageous embodiment of the method radiation is emitted in grazing incidence on the conveyor belt. It can also be detected in grazing incidence or skewed past the direction of the conveyor belt on the conveyor belt. As a result, small changes in shape of the conveyor belt, such as its defibration or a peeling connection of two ends can be determined.

In an advantageous embodiment, the monitoring device of the folder comprises a radiation emitter and a radiation detector. In other words, starting from a radiation source, the conveyor belt is exposed to a radiation flux and the scattered radiation is detected. The change or deviation of the scattered radiation (intensity, direction, or the like) is considered to be a measure of the deviation of the condition of the conveyor belt from a reference state, for example, the state of a good grade. The change can be an increase or a decrease. The emitted radiation may in particular be directional.

In order to increase the contrast between the various states, the conveyor belt may have at least one portion with increased reflectivity for the scattered radiation. The reflectivity changes with increasing operating time of the conveyor belt in the folder. In particular, either is advantageous a monotonous increase or a monotonous decrease.

If the folder includes a number, including a number, in a plurality of conveyor belts, the monitor may be assigned the number of conveyor belts and the monitor may detect the radiation scattered by a conveyor belt at least during a period of time.

In order to use only a small number of monitoring devices in the folder according to the invention for a large number of conveyor belts, the monitoring device can be moved by means of an actuator in the folder.

It is particularly advantageous if the monitoring device of the folding apparatus according to the invention is linked to the machine control. The information about the quality conditions of the conveyor belt or conveyors in the folder can be used for decisions of the machine control. In other words, a program-based machine control executes control options depending on the detected presence and / or quality state of the conveyor belt (s). For example, an automatic shutdown of the machine can be made with a lack of conveyor belt quality to avoid paper jams or paper misfeeds. Further, the operator may be alerted to a poor presence or quality condition by signal through a man-machine interface including, for example, a monitor or speaker. The signal can be a visible and / or audible signal (light signal and / or signal tone).

The folding apparatus according to the invention can be used on web-processing printing press of all types of printing methods, in particular in direct or indirect planographic printing, offset printing or the like. A folding apparatus according to the invention may be arranged downstream of a web-processing printing press. Typical substrates include paper, paperboard, organic polymeric materials or the like.

Figur 1

eine Skizze zur Erläuterung zweier häufig auftretender Degradationen von Transportbändern in Falzapparaten und der erfindungsgemäßen Überwachung dieser Gefahrenquellen eines Bruchs,

Figur 2

eine schematische Darstellung zur Erläuterung der erfindungsgemäßen Überwachung von gestreuter Strahlung von wenigstens eines Teils eines Transportbandes, wobei beispielhaft das Transportband Abschnitte erhöhten Reflexionsvermögens aufweist,

Figur 3

eine Ansicht einer vorteilhaften Ausführungsform einer Überwachungsvorrichtung für Transportbänder in einem Falzapparat,

Figur 4

eine Seitenansicht einer vorteilhaften Ausführungsform einer Überwachungsvorrichtung für Transportbänder in einem Falzapparat, und

Figur 5

eine schematische Darstellung einer Ausführungsform eines erfindungsgemäßen Falzapparates mit einer Anzahl von Transportbändern, denen Überwachungsvorrichtungen zugeordnet sind.

Further advantages and advantageous embodiments and developments of the invention will be described with reference to the following figures and their descriptions. It shows in detail:

FIG. 1

a sketch to explain two frequently occurring degradation of conveyor belts in folders and the inventive monitoring of these sources of risk of a break,

FIG. 2

a schematic representation for explaining the monitoring of scattered radiation according to the invention of at least part of a conveyor belt, wherein by way of example the conveyor belt has portions of increased reflectivity,

FIG. 3

a view of an advantageous embodiment of a monitoring device for conveyor belts in a folder,

FIG. 4

a side view of an advantageous embodiment of a monitoring device for conveyor belts in a folder, and

FIG. 5

a schematic representation of an embodiment of a folding apparatus according to the invention with a number of conveyor belts, which monitoring devices are assigned.

FIG. 1 shows a sketch to explain two frequently occurring degradations of conveyor belts in folders and the monitoring according to the invention of these sources of risk of breakage. Common conveyor belts for folders, whether flat or round conveyor belts, have a fabric-like or layered structure. Typically, their paths are straight in sections, their directions are changed by means of pulleys, and along their way they are under tension. Often, further elements are provided which are intended to fix the position of the conveyor belts, ie their way. Both pulleys and elements for Wegfixierung can Exert frictional forces on the conveyor belts. Conveyor belts often consist of at least one originally open band whose ends are brought together and fastened, so that a closed band is formed. The location of the connection is potentially weaker than other band sections, so that it can come to a replacement, because, for example, operate during operation Walk forces due to movement direction changes of the tensioned band. A conveyor belt may also have a plurality of such compounds.

In the figure 1 is a sketch of a section of a conveyor belt 10 is shown. The conveyor belt 10 is a closed belt along a path not specified here. There are two monitoring devices 12 are provided, the observation directions 13 perpendicular and skewed to the conveyor belt 10, which moves in the direction 14, extend. The axes of the observation directions 13, here perpendicular to the paper plane of Figure 1, advantageously with a small distance to the conveyor belt: The exact advantageous distance to the conveyor belt depends on its physical parameters, such as thickness, elasticity and structure (fabric or layer) and the like. It has been found that a distance of a few millimeters to a few centimeters (2 mm to 2 cm) is advantageous. On the shown portion of the conveyor belt 10, a peeling connection 16 is shown. Furthermore, the conveyor belt 10 has a point with defibration 18. The partially protruding ends of the peeling connection 16 and the protruding fibers of the defibration protrude into the viewing direction 13 of the monitoring device 12 as they pass, as the conveyor belt 10 moves in direction 14. *** " In particular, these degradations of the conveyor belt can be detected by means of the monitoring device 12 by detecting radiation scattered by the degradations, more precisely by the (degraded) parts of the conveyor belt 10 projecting partially into the observation direction 13.

FIG. 2 is a schematic illustration for explaining the monitoring of scattered radiation according to the invention of at least part of a conveyor belt, by way of example the conveyor belt having portions of increased reflectivity.

FIG. 2 shows a further geometry or arrangement for monitoring the conveyor belt 10 with a monitoring device 12. The conveyor belt 10 moves in the direction 14 past a detector 20. Scattered radiation 22, preferably visible or infrared light, is measured in the detector 20. The radiation 22 is scattered by a part 24 of the conveyor belt 10. The detection can take place in at least two ways during a period of time: On the one hand, the detection can be performed clocked whenever a certain portion of the conveyor belt 10 passes the detector 20, on the other hand, the radiation 22 scattered by a part 24 of the conveyor belt 10 is only measured when this part 24 passes the detector 20. The conveyor belt 10 shown in Figure 2, for example, two sections 26 with increased reflectivity. The increased reflectance refers to the wavelengths of radiation measured by the monitor 12. In other words, increased reflectance means that for at least a portion of the wavelengths detected, the conveyor belt 10 has a high reflectivity, typically greater than 50%, preferably greater than 80%, while for adjacent wavelengths the reflectance is less strong, typically less than 50%, preferably less than 20%. An increased reflectivity can be achieved by a colored strip or a colored fiber on or in the structure of the conveyor belt. Upon degradation of the conveyor belt 10, ie with increasing operating time of the conveyor belt 10, then the increased reflectivity changes. This change may be an increase or decrease: an increase may occur, for example, when a colored inner fiber emerges due to fiberizing out of outer fibers. A decrease may occur, for example, when a colored outer layer is removed due to abrasion. The monitoring device 12 has a connection 28 to an evaluation unit (not shown here in FIG. 2).

Figure 3 is a view of an advantageous embodiment of a conveyor belt monitor in a folder. The folder 30 faces between the side wall 32 of the operator side and the sides 34 of the drive side a number of conveyor belts 10 on (conveyor belt bank). The conveyor belts 10 extend over a roller 36, which is rotatably mounted on the side walls 32, 34. The conveyor belts 10, which are supported by the roller 36, pass through a chamber 38, which may be under pressure. The chamber 38 may inter alia serve to avoid contamination of the monitoring devices 12.

Two monitoring devices 12 are accommodated on a carriage 40, which is movable by means of a drive not shown in detail here, for example a servomotor with spindle drive or a linear motor, on a linear guide 42 substantially perpendicular to the running direction of the conveyor belts 10. In other words, the monitoring devices 12 are movable in the folding apparatus 30 by means of an actuator, comprising a slide 40 and a linear guide 42. The linear guides are fixed by means of recesses 44 on the side wall of the operator side 32 and the side wall of the drive side 34. A connection to the monitoring devices 12 runs via a cable train 46, which is supported by a traverse 48.

The monitoring devices 12 each comprise a radiation emitter, here a light emitter, for example a laser, and a radiation detector, here for example a photocell. The electromagnetic radiation 50 emanating from the light emitters of the monitoring devices 12 is at least partially scattered on at least part of the conveyor belts. These monitoring devices 12 can be used to determine the presence state of the conveyor belts 10. The use of laser radiation is particularly advantageous and therefore preferred, in particular because of its directionality, its spectral power density and low total power required. Radiation emitter and radiation detector can be combined in the form of a triangulation sensor.

FIG. 3 also shows two monitoring devices 12, which are supported by a receiving element 52. These monitoring devices 12 have radiation emitters and radiation detectors. Starting from the light emitters of the monitoring device 12, electromagnetic radiation 50 runs askew to Direction of the conveyor belts 10 to the conveyor belts 10 over. The electromagnetic radiation 50 propagates in this embodiment substantially perpendicular to the conveyor belts 10 and has a substantially constant distance from the conveyor belts 10. By means of these monitoring devices 12, detaching compounds or defibrings (see FIG. 1) can be detected particularly well. These monitoring devices 12 can be used in particular for determining the quality state of the conveyor belts 10. The use of laser radiation is also particularly advantageous for these monitoring devices 12 and is therefore preferred. The radiation emitter and the radiation detector of these monitoring devices 12 can be combined in the form of a triangulation sensor.

4 is a side view of an advantageous embodiment of a monitoring device 12 for conveyor belts 10 in a folding apparatus 30. Shown is a portion of a conveyor belt 10 which passes over rollers 36 and passes through a chamber 38. On a carriage 40, which is movable relative to the conveyor belt 10 substantially perpendicular to its direction of movement 14 by means of a linear guide 42, there is a monitoring device 12 which can emit and detect electromagnetic radiation 50. The monitoring device 12 has a connection 28 via cable lug 46 to an evaluation unit not shown here in detail. Furthermore, the monitoring devices 12 are shown, whose observation direction 13 is skewed and substantially perpendicular to the conveyor belt 10 (in the illustration of Figure 4 perpendicular to the paper plane).

5 shows a schematic representation of an embodiment of a folding apparatus according to the invention with a number of conveyor belts, which monitoring devices are assigned. The conveyor belts 10 carry signatures 64 through the folder 30 at least over a portion of a path. A folder 30 having only an exemplary configuration of various paths of the signatures 64 and various processing devices is downstream of a web-processing press 54. The printing substrate 56 initially passes a Cross cutter 58, which comprises a cutting cylinder 60 and a grooved cylinder 62 and in which signatures 64 are separated from the printing substrate 56. Below the cutting cylinder 60 and the grooved cylinder 62 on rollers 36 circulating conveyor belts 10 are shown, between which the first path 66 and the second path 68 passes through the folding apparatus 30. The conveyor belts 10 are monitoring devices 12, as described in more detail above assigned. The first path 66 and the second path 68, along which the signatures 64 travel through the folder 30, extend around a folding blade cylinder 72 to a jaw cylinder 74. The paths then separate. The first path 66 runs along a transport cylinder 76 between two conveyor belts 10, which revolve around rollers 36. Also, these conveyor belts monitoring devices 12 are assigned. Further, the path 66 extends via further transport cylinder 36 and a Schaufelradauslauge to a conveyor belt 10, which is associated with a monitoring device 12. The second path 68 leads via a gripper cylinder to a conveyor belt 10 with associated monitoring device 12. From there, the path 68 leads under a rotary blade folding unit 82, which presses signatures 64 through the gap formed by two folding rollers 84. The signatures 64 reach a further conveyor belt 10 with associated monitoring device 12.

The monitoring devices 12 may be designed according to the embodiments shown in FIGS. 3 and 4. The monitoring devices 12 have connections 28 to an evaluation unit 70 with a computing device. The signals generated in the monitoring devices 12, which are representative of the state of the respective associated conveyor belts 10, can be correlated in the evaluation unit 70 to predetermined values, for example in the form of a nominal-actual comparison to reference data stored in a memory, and thus into condition classes (presence state and / or quality state). In the embodiment of the folding apparatus 30 according to the invention shown in FIG. 5, the evaluation unit 70 is connected to the machine control 86, so that, depending on the result of the state class assignment, certain measures for the control of the machine, for example a shutdown or a signaling, can be executed. Furthermore, the machine controller 86 connects to a man-machine interface 88, which typically includes a display unit (eg, a monitor), an input unit (eg, a keyboard, a touch screen, a button, or the like), an optical or acoustic signal unit and the like. Information about the condition of the conveyor belts 10 in the folder 30 can be communicated to the machine operator by means of the man-machine interface 88 so that the machine operator can take appropriate measures, for example a change of one or more of the conveyor belts 10.

LIST OF REFERENCE NUMBERS

10

conveyor belt

12

monitoring device

13

direction of observation

14

movement direction

16

detaching connection

18

fibrillation

20

detector

22

scattered radiation

24

Part of the conveyor belt

26

Section with increased reflectivity

28

Connection to the evaluation unit

30

folding

32

Sidewall of the operator side

34

Side wall of the drive side

36

role

38

chamber

40

carriage

42

linear guide

44

Aufnehmung

46

trailing cable

48

traverse

50

electromagnetic radiation

52

receiving element

54

web-processing printing press

56

printing material

58

Sheeter

60

Scheid cylinder

62

grooved cylinder

64

signature

66

first way through the folder

68

second way through the folder

70

evaluation unit

72

folding blade

74

jaw cylinder

76

transport cylinder

78

gripper cylinder

80

Fan wheel

82

Rotationsschwertfalzwerk

84

folding rollers

86

machine control

88

Human-machine interface

Claims (11)

1. Folding apparatus (30) having at least one conveyor belt (10) which serves to convey signatures (64) at least over part of a pathway (66, 68) for the signatures (64) through the folding apparatus (30),
   characterised in that
   the folding apparatus (30) comprises at least one monitoring device (12) which is associated with the conveyor belt (10), the monitoring device (12) having a detector (20) for radiation (22) scattered by at least part (24) of the conveyor belt (10) over at least one period of time.
2. Folding apparatus (30) according to claim 1, characterised in that the radiation (22) is electromagnetic radiation (50) or ultrasound.
3. Folding apparatus (30) according to claim 1 or 2, characterised in that the monitoring device (12) comprises a radiation emitter and a radiation detector (20).
4. Folding apparatus (30) according to one of the preceding claims, characterised in that the conveyor belt (10) comprises at least one section (26) having an increased reflectance for the scattered radiation (22), wherein the reflectance changes, in particular increases monotonously or decreases monotonously, as the duration of operation of the conveyor belt in the folding apparatus increases.
5. Folding apparatus (30) having a plurality of conveyor belts (10) according to one of the preceding claims, characterised in that the plurality of conveyor belts (10) are associated with the monitoring device (12) and the monitoring device (12) detects the radiation (22) scattered by a conveyor belt (10) over at least one period of time.
6. Folding apparatus (30) according to claim 5, characterised in that the monitoring device (12) is movable in the folding apparatus (30) by means of an actuator (40, 42).
7. Folding apparatus (30) according to one of the preceding claims, characterised in that the monitoring device (12) is linked to the machine control (86).
8. Folding apparatus (30) according to one of the preceding claims, characterised in that the monitoring device (12) is designed to detect a condition of presence or a condition of quality of the conveyor belt.
9. Web-operated printing press (54), characterised in that it has at least one downstream folding apparatus (30), according to one of the preceding claims.
10. Method of monitoring at least one conveyor belt (10) in a folding apparatus (30), characterised by:

    - the detection of radiation (22) which is scattered by at least a part (24) of the conveyor belt (10) over at least one period of time;

    - the generation of a signal which is representative of the condition of presence or quality of the conveyor belt (10); and

    - the assignment of the signal to a condition category.
11. Method of monitoring at least one conveyor belt (10) in a folding apparatus (30) according to claim 10, characterised by:

    the emitting of radiation past the conveyor belt (10) at an angle which is askew to the direction of the conveyor belt (10).

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