EP1790605A1 - Machine for checking the completion of a stack formed out of printed sheets - Google Patents

Abstract

Device has a measuring device that measures the print product (11) and arranged along the collecting section. The measuring device (15) is formed by contact free measuring elements which are spaced transverse to the collecting section and which form a conveyor gap for the passing print product.

Description

The invention relates to a device for controlling the completeness of a formed on a collection section of transported sheet printing product and / or to control the relative position of the printed sheet of the printed product, arranged along with a collection along the printed products, respectively. Printing sheet detecting measuring device.

With saddle stitchers it is possible due to various influences that not all sheets are collected correctly. This may result in incomplete or otherwise faulty printed products that have to be rejected for quality reasons. For example, a copy to be dropped may have too many or too few sheets, a double or missing envelope. In addition, sheets may be opened incorrectly or it may be missing, for example, a designated pattern or other supplement.

It has long been known to control the completeness of printed products by measuring double and false deductions in investors. Also known is a saddle stitcher, which has a measuring device with a jockey wheel, which is pressed clockwise controlled for product transport of the gathering chain to the printed product to be measured. A ferrite core attached to one arm of the feeler wheel is immersed in a plunger coil. Due to the inductance change on the plunger coil is closed to the thickness of the printed product. The disadvantage is that the jockey wheel must be pressed with comparatively high forces, which can lead to a Walkt effect on the printed product. Goods samples, which are arranged on the printed product, can not be measured due to the mentioned high contact pressure. In addition, the measurement accuracy is not sufficient, for example, to detect the absence of envelopes. This measuring device is comparatively expensive and not flexible with respect to the measuring position in the printed product.

The invention has for its object to provide a device which excludes the disadvantages mentioned, which allows a more accurate and gentler completeness measurement of printed products and with the printed products can be assessed with samples.

The invention is achieved in a generic device characterized in that the measuring device is formed by transversely spaced to the collection line, forming a conveying gap for the passing printed products and non-contact measurement-effective measuring elements. Due to the capacitive and thus non-contact measurement, the printed products are not injured and product samples can also be detected without damage become. It has been shown that, especially at high production speeds, higher measurement accuracies can be achieved with the capacitive measurement than with the previously used feeler wheel. In addition, the space required is smaller and the construction is much simpler and less expensive.

According to a development of the invention, it is provided that the capacitance is measured with the aid of an inductance L and a capacitance C having resonant circuit LC. It has been shown that even small capacitances C can be measured very quickly and essentially without disturbances, so that the side of a saddle stitcher or a gathering machine can also be measured with high accuracy.

Optimum accuracy is possible when measuring along a collection path with multiple measuring devices.

Preferably, the capacitive measured values of the measuring devices formed with capacitors are correlated with one another, so that a further increase in accuracy can be achieved.

It is also possible to control samples and also to measure the position of a sample on a printed copy. Finally, when there is a gap in the product flow, a reference measurement for the condenser without paper can be carried out in full run, which leads to a further improvement of the measurement results, since mechanical and thermal drift phenomena can be easily compensated.

According to a development of the invention, the capacitive measurement of the printed products in the area of the saddle stitcher is combined with a similar measurement of the individual sheets in investors. This makes it possible to take into account varying paper properties in the measurement of the printed products. It is also an even higher accuracy possible because individual deviations of individual sheets can be taken into account in the interpretation of the total measured value.

The device according to the invention has, for the capacitive measurement of the printed products, at least one capacitor which can be arranged on a collecting path in that the printed products to be measured cover the collecting path. The capacitor may be arranged laterally at a distance from a side plate of the collecting line or above the collecting line. If the capacitor is arranged above the collecting line, then the printed product can be measured in the region of the fold. In principle, it is also possible to measure both laterally on the side plate and on the collecting route. The collection route could be part of a saddle stitcher.

Further advantageous features emerge from the dependent claims, the following description and the drawings.

Fig. 1

ein Querschnitt einer Sammelvorrichtung für Druckprodukte,

Fig. 2

schematisch eine räumliche Ansicht eines Druckproduktes mit einem an diesem angebrachten Warenmuster,

Fig. 3

eine Messkurve, welche mehrere Messpunkte mit kapazitiven Messwerten eines gemessenen Druckproduktes darstellt,

Fig. 4

schematisch eine Seitenansicht eines Sammelhefters und vier Anlegern, und

Fig. 5

ein Querschnitt einer Sammelvorrichtung mit einer alternativen Ausführung der erfindungsgemässen Vorrichtung.

Two embodiments of the invention will be explained in more detail with reference to a drawing. Show it:

Fig. 1

a cross-section of a collection device for printed products,

Fig. 2

1 is a schematic view of a printed product with a product sample attached thereto;

Fig. 3

a measuring curve which represents several measuring points with capacitive measured values of a measured printed product,

Fig. 4

schematically a side view of a saddle stitcher and four investors, and

Fig. 5

a cross section of a collecting device with an alternative embodiment of the inventive device.

The collecting device of a saddle stitcher 1 shown in Fig. 1 is used for example in a conventional manner for the production of brochures, magazines, newspapers, books and the like. It has a here only partly shown and known per se machine frame 2, to which two side plates 6 and 7 are fixed, which are opposite and relative to a vertical V-shaped inclined inwards. Over the side plates 6 and 7, a chain guide 9 is arranged, on which two strands 26 of an endless gathering chain 3 are guided. At this gathering chain 3 drivers 4 are mounted at equal intervals, which are provided for the transport of printed products 11. These printed products 11 are shown in FIG. 1 astride a support 5, which forms a ridge. The support 5 supports the printed products 11 in the region of a fold 12. From the fold 12 extend legs 11a and 11b of the Printed product 11 V-shaped down in the region of the side panels 6 and 7. Parallel to the fold 12 are front edges 14th

In the region of the side plate 7, a measuring device 15 is arranged, which has a capacitor 16 with two capacitor plates 17 and 18. Capacitor plate 18 is electrically grounded. Between the two capacitor plates 17 and 18 is located in the side plate 7, a window 8, so that the side plate 7 provides no or only a small contribution to the capacity of the capacitor 16. However, the window 8 is not mandatory, it is also possible to use the grounded side plate 7 as the one capacitor plate. The capacitor plate 17 is connected via a line 20 to a grounded via line 21 control device 23. The control device 23 serves to evaluate the measured capacitance and is connected, for example, to a display device, not shown here, as well as further control means.

The two capacitor plates 17 and 18 are arranged so that each of the conveyed printed products 11 a leg 11b passes between them. On an outer side 13 of the leg 11b, a brush 10 may be attached, which in the region of the measuring device 15 slightly presses the leg 11b against the outside of the side plate 7. This ensures that the leg 11 b passes between the two side plates 7 and the capacitor plate 17. The brush 10 could also be replaced by other means, for example by a blower.

Another capacitor 25 may be arranged above the collecting device in the region of the support 5. This capacitor 25 also forms a measuring device and is connected via a signal line 22 to the control device 23. Pad 5 corresponds to the capacitor plate 18 or 7 and must in turn be grounded connected to the machine.

The measuring device 15 is used to measure one or more capacities of the printed products 11 passing through a capacitor. These measured values are the capacitance of the printed product 11 in the region of a leg 11b or 11a and / or the capacitance in the region of the fold 12 Capacities are determined, for example, by individual or multiple sheets and, for example, by a pattern 19 fastened to the outside 13. An envelope can also contribute to increasing capacity. The capacity of the printed products 11 can be very large, so that the envelope then also contributes correspondingly little to the total capacity of the product. The thickness of a thin sheet may be, for example, 0.1 mm. This thickness can also vary. The thickness of the pattern of goods, for example a bag, can be several millimeters and the resulting capacity will be correspondingly large.

The capacitor plate 17 is fixed to a carrier 24 so that between the capacitor plate 17 and the outside of the side plate 7, a certain distance is formed. The carrier 24 is preferably formed so that the capacitor plate 17 is displaceable. The displacement can be made so that the capacitor plate 17 can be moved parallel to the side plate 7 upwards or downwards. Also conceivable is a shift in the transport direction or against the transport direction, but you will move in the rule instead of a mechanical shift the measurement time, which has the same effect. In the same way, if the side plate 7 is not used as the counter-plate of the capacitor 16, the capacitor plate 18 can be moved. This makes it possible to adapt the thickness measurement to the format of the printed product 11. In the case of printed products 11 with very short legs 11a and 11b, it is certainly possible to measure in the region of the fold 12. The capacitor 25 is also attached to a carrier not shown here and can also be moved.

A capacitive measurement is simultaneously possible in the region of the leg 11 b with capacitor 16 and in the region of the fold 12 with the capacitor 25. In principle, however, it is also possible to measure only in the region of the fold 12 or only in the region of the leg 11b. In principle, the leg 11a could also be measured simultaneously with a further capacitor.

The capacitors are preferably in mutual correlation to increase the accuracy of measurement. Preferably, the capacitance is measured by means of an LC resonant circuit. This LC resonant circuit is excited by an oscillator circuit. To improve the stability of the oscillations, an amplitude control can be provided. With a comparator stage, the sinusoidal oscillations can be converted into a rectangular signal, which is processed by an evaluation unit. In the same way, a plurality of capacitors 25 may be provided.

The measurements are preferably carried out continuously and several times per cycle. This makes it possible to measure a thickness profile on a printed product 11. This will be explained in more detail below with reference to FIGS. 2 and 3.

FIG. 2 schematically shows the printed product 11 in the folded state, as it is transported astride, for example, on the saddle stitcher 1. The fold 12 and the front edges 14 are parallel to each other and to the conveying direction. A head edge 27 forms a leading edge and a foot edge 28 a trailing edge. The sample 19 is attached to the outside 13, for example, glued. Instead of the pattern 19, another part, such as a card, may be attached. The printed product 11 may, for example, consist of a plurality of sheets and the aforementioned pattern 19. The measurements can now be carried out such that, according to FIG. 3, the thickness of a continuous printed product 11 is measured at the points P2, P3, P4 and P5. The measurements P2, P4 and P5 correspond to the thickness of the printed product 11 without the product pattern 19 and the measured thickness at the point P3 of the total thickness, printed product and product pattern 19. Based on the measurements at the points P2 to P5, the curve 29 shown in FIG become. If, for example, a curve runs without the increase in the region of the point P3, it can be concluded that the goods pattern 19 is missing. Due to the position of the measurement at the point P3 also an unscheduled displacement of the pattern 19 can be determined. It can also be seen a printed product 11, were mounted on the two samples 19. Regardless of the thickness of the fabric pattern 19, the thickness of the printed products at the points P2, P4 and P5 are determined. As a result, missing print products or a missing envelope can be determined.

The measurement P1 takes place in a gap of the product flow. This measurement can be used as a reference measurement for the capacitance without product in the capacitor, which can be used to optimize the measurement accuracy, as this is the best way to eliminate the drift phenomena of the measuring system.

In the embodiment according to FIG. 4, investors A1 to A4 are provided in addition to the collecting device, with which sheets 36 are withdrawn in a manner known per se from a stack, not shown here, and deposited on the collecting device. The investors A1 to A4 lie along a collection path 5. The printed sheets 36 may already be provided with a sample 19 or the like. In principle, however, it is also possible to apply the product pattern 19 or the like only in the area of the collecting device. The conveying direction of the feeders A1 to A4 is indicated in each case by an arrow 34 and the conveying direction of the collecting device by the arrow 35. The measuring device 15 is preferably in the conveying direction after the investors A1 to A4 and thus preferably at the end of the collection line S of the collecting device. In the area of the measuring device 15, the collecting process is completed and the printed product 11 should be complete.

The printed sheets 36 are measured individually with respect to their capacity. For this purpose, capacitors 30 to 33 are provided, which are each arranged between an investor A1 to A4 of the collecting device or in the region of the feeder A1 to A4. The Capacitors 30 to 33 are also connected to the measuring device 15 and the control device 23, respectively. This makes it possible to measure the sheets individually. It is possible to detect individual differences in the actually identical printed sheets, which show themselves in smaller deviations of the capacitive measured value, in the measurement of the total capacity in the area of the collecting device. This makes it possible to adapt the tolerance value during the measurement in the area of the collecting device to the individual measurement in the area of the feeders A1 to A4. If, for example, it is determined by measurements on the capacitors 30 to 33 that the thinnest printed sheet causes a relative change in capacitance of 0.1, then the tolerance value is automatically set, for example, to 0.05, and thus to half the value of the thinnest printed sheet. Missing in the printed product 11 such a sheet 36, this can be determined with the set tolerance of 0.05. The tolerance value is then the optimum value for detecting this thinnest printed sheet. If, on the other hand, the relative change in capacitance of the thinnest printed sheet is 0.2, a tolerance value of 0.1 is already sufficient to detect a lack of this thinnest printed sheet. This can always be worked with an optimal tolerance value.
Very often, the top sheet 36 of the printed product 11 is an envelope; This is often the thinnest bow. Therefore, one can detect the presence of this outermost sheet with an image capture system included in the measurement device 15 by comparing the current image with the reference image previously captured in a correct print product. Now, the tolerance can be aligned to the second-thin signature, which in turn allows a reliable completeness check.

The illustrated in Fig. 5 alternative embodiment of the inventive device consists of a support frame 41 to which a saddle-shaped collecting device 1 for the rittlingweise transport of the printed products 11 resp. the printing sheet 36 is fixed, and a measuring device 15, which is formed by transverse to the collection device forming a collecting device, a conveying gap for the one leg 49 of the passing printed products 11 limiting and non-contact cooperating measuring elements. The measuring elements 45, 46 located opposite each other on a side wall 42, 43 in the region of passage openings 44 each have a cavity 47, 48, to which compressed air is supplied. Preferably, the measuring element 45 provided within the collecting device is fixed to the side wall 43 of the collecting device, whereas the opposite measuring element 46 is guided movably perpendicular to the side wall 43 and resiliently supported on the supporting frame 41 on a compression spring or the like, not shown. Compressed air is supplied to both cavities 47, 48 of the measuring elements 45, 46, which flows through the passage openings 44 in the side wall 43 under the legs 49 and through nozzle-like openings 50 from the cavity 48 of the movable measuring element 46 to the outside of the leg 49, on both sides of the leg 49, an air cushion 52 resp. Gap, so that a non-contact measurement can arise.
The compressed air supplied on both sides of the leg 49 flows along the leg 49 and emerges on the one hand via openings 51 in the side wall 43 and on the other hand on the side edges of the movable measuring element 46 again.

Due to the mobility of the measuring element 46, a change in the thickness of the leg 49 can be measured by detecting the distance of the measuring element 46 that is changed with respect to the side wall 43 or another reference point and converted into a value comparable to a desired value. This distance measurement can be done, for example, inductively or by laser measuring device.

An embodiment of the measuring device 53, as shown in Fig. 5, could also be used for a collection channel of an adhesive binder upstream gathering machine, in which the printed sheets collected or stored one above the other. be transported. For this purpose, a channel bottom of the collecting channel would be used instead of a side wall.

Claims (11)

Apparatus for checking the completeness of a printed product (11) formed on a collection line of transported printing sheets (36) and / or for controlling the relative position of the printing sheets (36) of the printed product (11), with a printing product (11 ) resp. Sheet (36) detecting measuring device (15), characterized in that the measuring device (15) by transversely to the collecting distance, a conveying gap for the passing printed products (11) forming and non-contact measurement-effective measuring elements (45, 46) is formed. Apparatus according to claim 1, characterized in that the measuring device (15) is arranged respectively at the conveying end of a collecting section. Apparatus according to claim 1 or 2, with a measuring device (15) arranged at the collecting line of a saddle stitcher. Device according to claim 1 or 2, with a measuring device (15) arranged at the collecting line of a collating machine. Apparatus according to claim 3, which is arranged along a saddle-shaped collecting route of a saddle stitcher, characterized in that the conveying gap of the measuring device (15) is associated with a lateral leg (49) of the astride transported printed products (11). Apparatus according to claim 5, characterized in that the measuring device (15) by an inductance L and capacitance C resonant circuit of the capacitance C of a passing printed product (11) measuring capacitor (16) is formed. Device according to one of claims 3 to 6, arranged along the collecting line sheet feeders (A1 to A4), characterized in that along the collection line a plurality of measuring devices (15) are arranged, preferably between two sheet feeders (A1 to A4). Device according to one of claims 1 to 5, characterized in that the measuring elements (45, 46) of the measuring device (15) on a guide element (43) forming a conveying gap are arranged opposite each other and to the compressed air supply to the measuring elements (45, 46). facing surfaces of the printed product (11) resp. a leg (49) of the printed product (11) are formed. Apparatus according to claim 8, characterized in that at least one measuring element (46) perpendicular to the guide element (43) is guided by this liftable. Apparatus according to claim 8 or 9, characterized in that the measuring elements in each case a cavity (46, 47) with the surfaces of a printed product (11) resp. a thigh (49) of the printed product (11) directed through openings (44, 50) for the compressed air. Device according to one of claims 8 to 10, characterized in that the movable measuring element (46) is connected to a distance measuring device (53).

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