DK148618B - PROCEDURE FOR DIVISION OF SHEET OR LEAF SHAPED ITEMS - Google Patents

Description

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BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of dividing sheet or leaf-shaped articles, especially tobacco leaves or parts thereof, to produce sections, for example, cover sheets for cigars, in a predetermined form, wherein the articles are placed on a carrier and illuminated with a bundle of electromagnetic radiation reflected by the objects and received by a radiation sensitive sensor.

-With many machining methods, it is necessary to inspect the contour or surface condition of the objects, for example to exclude objects that do not meet the requirements or to cut damaged surface areas.

From DE Publication No. 2,538,964, a division of a tobacco leaf half is known by means of cutting tools arranged in a fixed orientation relative to each other. The leaf is scanned with two or more photosensitive organs to determine the most crystalline outer points of the tobacco leaf, similar to the contours of the cutting tools. Although the publication states that more than two photosensitive organs can be used, it does not suggest scanning the surface of the tobacco leaf itself, which means that any errors in the surface are not detected.

NL Patent Specification No. 6,413,559 describes cutting of tobacco leaves into ribbons which are scanned for defects. As soon as a defect is found, a cutting member is put into position to cut the defect. The bands are further bonded together to form a band of a desired length. There is no provision in the NL petition to cut out the parts that have the least possible defects.

SE Patent Nos. 209,324 and 189,419 also include scanning of web-shaped material, in particular paper webs. Neither do these writings indicate scanning the contour of an object or its surface.

In the known methods, it is necessary to employ operators to monitor the work, which is tiring for them, whereby errors can easily occur when the operators become tired, and therefore often have to change operators, which is expensive for the work.

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It is the object of the present invention to provide a new machining method in which the splitting of the objects can be carried out without having to be monitored by operators, by accurately determining any irregularities in the surface of the object so that accurate coordinates of these irregularities can be obtained and using these coordinates in a calculator for managing appropriate tools.

The method of the invention is characterized in that the variations in the radiation intensity reflected by the objects received by the sensing means are detected to determine the contours of the objects and the presence of defects, and that the output signal of the sensing means is used to control the cutting of the objects in such a way that they desired sections are taken from areas that are within the object's contour and have a minimum of defects.

In the method according to the invention, the signal from the sensing means can advantageously be used to detect slots or holes in the article, the cutting of the article being controlled in such a way that the sections do not include such slots or holes.

Advantageously, in the method according to the invention, the pattern represented by the signal from the sensing means can be compared with a set of reference patterns, so that the best reference pattern is used to control the cutting of the objects.

The present invention will now be described in more detail with reference to the accompanying drawing, which schematically illustrates an apparatus for carrying out the method of processing tobacco leaves in accordance with an embodiment of the present invention. .

Reference number 1 shows a leaf carrier on which are placed two halves of an extended tobacco leaf. The manner in which this arrangement is carried out is outside the scope of the present invention. The leaf halves may be from the same tobacco leaf, but they can. as well stem from different leaves. On the carrier, the upper half of the leaf is damaged by one hole.

The leaf support is moved to a different position by moving it to a detection station or by moving the detection station over. leaf wearer.

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The detection station comprises a means 2 for transmitting an electromagnetic radiation bundle 3 which, upon reflection from the leaf support 1 'or from the tobacco leaf lying thereon, is received by a sensing means 4. The beam can be moved back and forth by the means 2 along scan lines across the leaf support, but any suitable image of the radiation bundle and any scanning method is within the scope of the present invention.

As soon as a change in the intensity of the reflective beam is due to the radiation bundle passing the edge of the tobacco leaf on the carrier 1, a signal is generated by the sensor 4, which signal is used for the circuit which regulates a cutting member 5.

In the illustrated embodiment, the circuit includes a comparator 6. During the scanning of the tobacco leaf on the carrier 1 ', the signals evoked by the sensor 4 may be composed to form a given pattern representing the shape of the tobacco leaf and of any defect in the tobacco leaf such as holes, fractures, etc. This representative pattern is compared in comparator 6 with a number of reference patterns, as shown in the figure, in the form of a number of possible patterns on a belt that can be scanned. When in the comparator 6 the most similar pattern is found, ie. In a cutout pattern in which the cutouts are free of defects, in the comparator 6, a signal is initiated to start the cutter 5 in accordance with this cutout pattern.

Of course, the signals can be transmitted in a digital form from the sensor to the comparator, while the reference patterns may be stored in the digital form in a computer's memory.

The cutter 5 is a tool capable of cutting each tobacco leaf at high speed. In addition to the known cutting heads in which a knife protrudes from the surface of a suction head, a laser beam can be used to heat split or heat cut a blade.

Cutting is carried out in position 1 "by the carrier 1, where additional means may be provided for receiving the formed portions which may then be sent to a packaging machine or storage coil.

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For example, by using the method of the invention in the tobacco industry for the manufacture of cover leaves, one can proceed as follows. The half tobacco leaf is scanned using a set of photodiodes, where each diode measures the light intensity in a small square part of the surface. The intensity shows whether there is - tobacco material, - a vein, or - no material in that part. ·. The signal generated by the diode is sent to a calculator to which all the signals from the diodes are used to form a total picture of the half tobacco leaf. Depending on the program used in the calculator, the calculator will control tools, such as a cutting edge cutter in the shape of the desired cover sheet design, for cutting the cover sheet, taking into account the location of veins, holes, defects or other defects, and keeping within the contour of the blade.

Although the invention is explained by an example from the tobacco industry, the scanning system may also be used in other areas, for example, within the leather industry for the cutting of skins.