Patent Description:
In tobacco industry a variety of rod-like articles are manufactured, such as cigarettes with a multi-segment mouthpiece, multi-segment filter rods. Segments of such articles are typically produced in a continuous process by cutting a continuous rod into individual segments or cutting the rod into bars and then cutting the bars into single segments. The manufacturing process requires production of semi-final products that comprise both filled and tubular segments, wherein the filled segments may be filled with a variety of filler materials used in the tobacco industry, such as tobacco material, processed tobacco material, filtering material or material necessary to form segments of special properties, such as segments through the smoke in the final product is not filtered, but only flows and is cooled. Both the finished tobacco products and the semi-final products may end with a tubular segment, i.e. a hollow segment without a filling, wherein the tubular segment may be thin-walled or a thick-walled segment. From the point of view of the quality of such products and semi-final products, it is important that the tubular end segments have a length whose tolerance range is narrow, i.e. that for the user of the products, they have the same length. Currently there are no systems that allow direct illumination of the front surface of a segment it the multi-segment rod-like article, where the scattering of the light in the material of the segment would enable the measurement of article parameters, including segment lengths. There is a demand on the market for a measuring system that allows additional measurements in addition to measuring the length of a tubular segment.

<CIT> discloses an apparatus for testing the end portions of cigarettes to detect end portions containing insufficient quantities of tobacco, which has a conveyor which transports the cigarettes sideways past at least two testing stations each of which accommodates a discrete capacitive and/or photoelectronic testing unit.

There is a need to efficiently produce multi-segment rod-like articles so as to ensure precise control over the production of individual segments, in particular end segments.

The object of the invention is a measuring system and a method for measuring parameters of a multi-segment rod-like article according to the appended claims.

The solution according to the invention enables precise measurements of products and semi-final products, with particular emphasis on the end segments. The high measurement precision is provided by the fact that the beam of high intensity of non-scattered light illuminates directly the front surface of the inner filled segment, and only light scattering through the material of this segment transmits information about the segment and its position. In particular, it makes it possible to verify geometrical parameters, for example the length of the tubular segments, the length of the rod-like article, and moreover, it makes it possible to verify the quality of the edge, for example the break of this end edge, and also to verify the position of the inner segment. It is suitable for the inspection of various types of products where end segments are hollow.

The object of the invention is described in more detail with reference to embodiments shown in the drawing, wherein:.

The present invention relates to the determination of parameters of multi-segment rod-like articles comprising at least two segments, which will be referred to herein as multi-segment rod-like articles. The multi-segment rod-like article <NUM> shown in <FIG> is a five-segment article comprising a first end segment <NUM>, a first inner segment <NUM>, a second end segment <NUM>, a second inner segment <NUM>, and a middle segment <NUM>. The first end segment <NUM> has a form of a tube, it is the first tubular end segment <NUM>, the second end segment <NUM> also has a form of a tube, this is the second tubular end segment <NUM>. Both the first tubular end segment <NUM> and the second tubular end segment <NUM> may be made of paper or thin cardboard. The multi-segment rod-like article <NUM> in <FIG> has the thickness shown greater than in the other embodiments. Moreover, it may be in the form of a thick-walled tube made of a filtering material or other material. The tubular segment is open on both sides, wherein the finished rod-like article does not contain any structural or filling elements inside the tubular segment, so that the light beam may pass unimpeded through the interior of the tubular segment. The thick-walled tubular segment may have a circular, square, triangular opening or in a cross-section it may have a shape of any other figure.

The first inner segment <NUM> is a filled segment, and similarly the second inner segment <NUM> is a filled segment. The filled segments <NUM>, <NUM> are in the form of a cylinder comprising a filler material used in the tobacco industry. The filler material may be a filtering material, a shredded tobacco material, a processed tobacco material, a material with aromatic substances etc. The materials used in the tobacco industry are typically transmissive to electromagnetic radiation both in the visible and the invisible range. The fibers of the filtering material are positioned in such a way that these fibers connect at multiple points to form a spatial permeable structure, the light of the light beam incident on such a structure is scattered in different directions. In the following description, a beam of electromagnetic radiation will also be referred to as a light beam, for simplicity. In the presented example of a five-segment rod-like article <NUM>, the middle segment <NUM> has the form of a tube, wherein the middle segment <NUM> may be made of any material, and it may be filled. The segments of the multi-segment rod-like article <NUM> are typically wrapped over the entire length of the article in a wrapper material <NUM>, for example a tissue paper. Filled segments <NUM> and <NUM> may have their own wrapper material. The segments may be formed in a continuous process by cutting the continuous rod into individual segments or cutting the continuous rod into bars and then into individual segments, the segments may be filled in a discontinuous process. The thicknesses of the wrapper materials are not shown.

The presented five-segment rod-like article <NUM> is an article symmetrical with respect to a plane S, perpendicular to an axis n of the five-segment rod-like article <NUM>. The article may be split along the plane S into two identical multi-segment rod-like articles with a length equal to half the length of the five-segment rod-like article <NUM>. The resultant multi-segment rod-like article comprises the tubular end segment <NUM> or <NUM>, the filled segment <NUM> or <NUM>, and a half of the middle segment <NUM>.

<FIG> shows a three-segment rod-like article <NUM>' comprising the first end segment <NUM>, the filled segment <NUM> and the second end segment <NUM>. The first end segment <NUM> is in the form of a tube, it is the first tubular end segment <NUM>, the second end segment <NUM> is also in the form of a tube, this is the second tubular end segment <NUM>. As with the article of <FIG>, the first tubular end segment <NUM> and the second tubular end segment <NUM> may be made of any material and may have arbitrary wall thickness. The three-segment rod-like article <NUM>', is also the article symmetrical with respect to the plane S perpendicular to the axis n of the article.

<FIG> shows a three-segment rod-like article <NUM>" that is in the form of a cigarette and comprises a first tubular end segment <NUM> and two filled segments: the filled segment <NUM> comprising filtering material and a segment <NUM> comprising shredded tobacco.

The measuring system <NUM> shown in the embodiment in <FIG> comprises a transporting device <NUM>, a first illuminating device <NUM>, a second illuminating device <NUM>, and a registering device <NUM> for capturing an image. The transporting device <NUM> may be in the form of a drum conveyor <NUM> provided with transport flutes <NUM> adapted to receive and transport multi-segment rod-like articles <NUM> (alternatively, the transporting device may be in the form of a belt conveyor provided with flutes for multi-segment rod-like articles). The drum conveyor <NUM> has an axis of rotation k and rotates in the direction shown by the arrow. The transport flute <NUM> is in the form of a cylindrical recess with an axis m, the multi-segment rod-like article <NUM> with a longitudinal axis n is placed in the transport flute <NUM> such that the axis n of the multi-segment rod-like article <NUM> substantially coincides with the axis m of the transport flute <NUM>. The measuring system <NUM> is also shown in <FIG>, where a section through the drum conveyor <NUM> is visible (axis of rotation k lies in the plane of the section) and the multi-segment rod-like article <NUM> as shown in <FIG> is in measurement position M. The first illuminating device <NUM> generates a first beam of light <NUM> with an axis u, wherein the axis u is disposed parallel to the axis n of the multi-segment rod-like article <NUM>, moreover, the axis n and the axis u may substantially coincide when the multi-segment rod-like article <NUM> is at measurement position M, in which it is illuminated by the first illuminating device <NUM>. The second illuminating device <NUM> generates a second light beam <NUM> with an axis v, wherein the axis v is located in parallel to the axis n of the multi-segment rod-like article <NUM>, moreover, the axis n and the axis v may substantially coincide when the rod-like article <NUM> is in measurement position M, in which it is illuminated by the second illuminating device <NUM>. The registering device <NUM> for registering the image is located above the measurement position M. The first illuminating device <NUM> and the second illuminating device <NUM> may be positioned such that the axis u of the first light beam <NUM> from the first illuminating device and the axis v of the second light beam <NUM> from the second illuminating device coincide. The registering device <NUM> may be in the form of a camera and may include several image registering devices.

At measurement position M, the first light beam <NUM> from the first illuminating device <NUM> passes through the interior of the first tubular end segment <NUM> and illuminates the first filled segment <NUM>. The light that has passed through the first tubular end segment <NUM> is scattered by the material of the first filled segment <NUM> and partially passes through the wrapper material <NUM>, wherein a part of the scattered beam that reaches the registering device <NUM> is designated as <NUM>. The second light beam <NUM> from the second illuminating device <NUM> passes through the interior of the second tubular end segment <NUM> and illuminates the second filled segment <NUM>. The light, which has passed through the first tubular end segment <NUM> is scattered and partially penetrates through the wrapper material <NUM>, the part of such scattered beam that reaches the registering device <NUM> is indicated as <NUM>. The first light beam <NUM> passes centrally through the first tubular end segment <NUM>, the second light beam <NUM> passes centrally through the second tubular end segment <NUM>, wherein it is possible to illuminate the filled segment not centrally, possibly at a slight angle. After passing through the tubular end segments <NUM>, <NUM>, both the first light beam <NUM> and the second light beam <NUM> and are not scattered and their intensity is maintained.

The registering device <NUM> receives ambient light reflected from the side surface 1A of the multi-segment rod-like article as well as the scattered light from the illuminating devices <NUM> and <NUM>. <FIG> shows a registered image P of the multi-segment rod-like article <NUM>. The image P shows an exemplary outline of the multi-segment rod-like article <NUM>, wherein the bold lines indicate the edges and surfaces of the segments, where 2A - an edge of the first tubular end segment <NUM>, 3A - a front surface of the first filled segment <NUM>, 4A - an edge of the second tubular end segment <NUM>, 5A - a front surface of the second filled segment <NUM>. The position of the first front surface 3A of the first filled segment <NUM> is defined as the boundary of the scattering region 3B where the first light beam <NUM> is scattered by the material of the first filled segment <NUM>. The position of the second front surface 5A of the second filled segment <NUM> is defined as the boundary of the scattering region 5B in which the second light beam <NUM> is scattered by the material of the second filled segment <NUM>. The image P is processed in a processing unit <NUM>. The processing unit <NUM> is configured to determine the parameters of the multi-segment rod-like article <NUM> such as, for example, a length a of the first tubular end segment <NUM> measured as the distance between the edge 2A of the first tubular end segment <NUM> and the front surface 3A of the first filled segment <NUM>, a length b of the second tubular end segment <NUM> measured as the distance between the edge 4A of the second tubular end segment <NUM> and the front surface 5A of the second filled segment <NUM>, a length c of the multi-segment rod-like article <NUM> measured as the distance between the edges 2A and 4A, and a distance d between front surfaces 3A and 5A. The processing unit <NUM> is configured to detect the position of the first filled segment <NUM> and the second filled segment <NUM>, a defective position is defined as a position of a line corresponding to the front surface 3A of the first filled segment <NUM> other than perpendicular to the axis n of the multi-segment rod-like article <NUM>, a defective position is defined as a position of a line corresponding to the surface 5A other than perpendicular to the longitudinal axis n of the multi-segment rod-like article <NUM>. Information about the determined parameters of the rod-like article <NUM> is sent to a controlling unit <NUM>, the controlling unit <NUM> may send a signal to reject the defective multi-segment rod-like article <NUM>. Image quality (contrast enhancement, image brightness) may be improved by the use of additional illumination in the form of light sources <NUM>, <NUM> illuminating the side surface 1A of the multi-segment rod-like article <NUM>. Cameras are known which are equipped with lamps arranged around the camera lens for illumination of the camera field of view.

An example of a manufacturing process parameter is a distance e between the front surface 3A of the first filled segment <NUM> and the first illumination device <NUM>. With the first illumination device in a fixed position, a change in the distance e may indicate an incorrect position of the multi-segment rod-like article <NUM> in the transport flute <NUM> in an axial direction along the axis m.

In the embodiment shown in <FIG> and in the below-discussed embodiment presented in <FIG>, symmetrical semi-final products are shown in the form of the rod-like articles ended on two sides by the tubular end segments <NUM> and <NUM>. The measuring system <NUM> according to the invention may be configured for multi-segment asymmetric rod-like articles ended on one side with a tubular segment. For example, the measuring system <NUM> may be equipped with one illumination device, if the product whose parameters are measured is a cigarette provided with a mouthpiece ended with a tubular segment, for example shown in <FIG>.

<FIG> shows an image P' of a defective multi-segment rod-like article which has a broken line representing the first edge 2A', indicating deformation of the first edge of the first tubular end segment <NUM>, and furthermore the light scattered by the second filled segment <NUM> forms a line corresponding to the front surface 5A' positioned not perpendicularly to the axis n of the multi-segment rod-like article <NUM>, which indicates a deformation or defective position of the second filled segment <NUM>, for example rotation of the filled segment <NUM> when a filled segment with a length close to the segment diameter is used.

An image P" shown in <FIG> for a three-segment rod-like article is analogous to the image P shown in <FIG> for a five-segment rod-like article. The scattering regions 3B, 5B, 3D registered in the images may differ depending on the type of material of the filled segments <NUM>, <NUM> and the wall thickness of the tubular end segments <NUM>, <NUM>. <FIG> shows an exemplary image P‴ for the multi-segment rod-like article <NUM>' in the form of a cigarette.

<FIG> shows a second embodiment of the measuring system <NUM>' wherein the first light beam <NUM> partially passes through the first tubular end segment <NUM> and illuminates the first filled segment <NUM>, further illuminating the first edge 2A of the first tubular end segment <NUM>. The light incident on the first edge 2A is scattered and reaches the registering device <NUM> as a beam <NUM>. The second light beam <NUM> partially passes through the second tubular end segment <NUM> and illuminates the second filled segment <NUM>, and further illuminates the second edge 4A of the second tubular end segment <NUM>. The light incident on the second edge 4A is scattered and reaches the registering device <NUM> as a beam <NUM>. The image P of the multi-segment rod-like article <NUM> is formed, inter alia, by the light reflected and partially scattered by the first edge 2A and by the second edge 4A and the light scattered by the first filled segment <NUM> and by the second filled segment <NUM>.

Claim 1:
A measuring system for measuring parameters of a multi-segment rod-like article (<NUM>, <NUM>', <NUM>") comprising at least one filled segment (<NUM>, <NUM>) and at least one tubular end segment (<NUM>, <NUM>), wherein the measuring system comprises:
- a transporting device (<NUM>) for transferring the multi-segment rod-like article (<NUM>, <NUM>', <NUM>") along a path of movement (R) transversely to an axis (n) of the multi-segment rod-like article (<NUM>, <NUM>', <NUM>"), wherein the transporting device (<NUM>) is provided with transport flutes (<NUM>);
- at least one illuminating device (<NUM>, <NUM>);
characterized in that:
- the at least one illuminating device (<NUM>, <NUM>) is configured for generating a light beam (<NUM>, <NUM>) for illuminating a front surface (3A, 5A, 3C) of the filled segment (<NUM>, <NUM>) by passing through the interior of the tubular end segment (<NUM>, <NUM>);
- the measuring system further comprises:
- a registering device (<NUM>) for registering an image (P, P", P‴) of the multi-segment rod-like article (<NUM>, <NUM>', <NUM>"), wherein the registering device (<NUM>) is configured to receive light of the light beam (<NUM>, <NUM>) scattered by the material of the filled segment (<NUM>, <NUM>), which penetrates through a material of a wrapper (<NUM>) of the multi-segment rod-like article (<NUM>, <NUM>', <NUM>") and reaches the registering device (<NUM>), forming an outline of the front surface (3A, 5A, 3C) of the filled segment (<NUM>, <NUM>) in the image (P, P", P‴); and
- a processing unit (<NUM>) configured to process the image (P, P", P‴) of the multi-segment rod-like article (<NUM>, <NUM>', <NUM>") registered by the registering device (<NUM>) and to determine the production process parameters and/or parameters of the multi-segment rod-like article (<NUM>, <NUM>', <NUM>").