Patent Description:
In its most traditional form, a filter segment for a smoking article consists of a cylinder of filter material (for example, cellulose acetate) and tipping paper which covers the cylinder of filter material.

Known in the tobacco industry are embossed filters (or, more precisely, partly embossed filters) used as alternatives to this type of filter segment to provide different sensations during a smoke.

In addition to the traditional filter segment, an embossed filter segment includes embossed tipping paper placed between the cylinder of filter material and the tipping paper. More specifically, the embossed tipping paper comprises portions of embossed tipping paper alternated with portions of smooth tipping paper.

In other words, an embossed filter segment comprises at least a first portion which is embossed (that is, which comprises a portion of embossed tipping paper) and at least a second portion, adjacent and contiguous to the first portion, which is not embossed (that is, which does not comprise any portion of embossed tipping paper).

A prior art production machine for making embossed filter segments comprises:.

In order to obtain a good quality product, it is important for the embossed portion of the embossed filter segment to be of the right length. In other words, the length of the embossed portion of the embossed filter segment must not differ from a reference value by more than a certain tolerance. This is not always the case, however, especially on account of the elasticity of the tape of embossed tipping paper (especially the embossed parts of the tape).

In this regard, patent <CIT>) discloses a device for inspecting the embossed filter rod.

This prior art device comprises a camera which is located upstream of the cutting means of the machine for making the embossed filter segments and which captures, at a certain frequency, circumferential images of the embossed filter rod as it moves towards the cutting means.

The device also comprises a processing unit which receives the images captured by the camera and which, based on these images, calculates the length of the embossed filter segment after the action of the cutting means. In order to calculate the length, the processing unit must necessarily receive not only the images captured by the camera but also a phase signal relating to the real cutting position.

Lastly, based on the calculated length, the processing unit drives the cutting means of the embossed filter segment production machine and, if necessary, adjusts the position where the embossed filter rod is cut.

As the embossed filter rod moves towards the cutting means, however, the embossed filter rod tends to move uncontrollably. Consequently, the circumferential images captured at this stage do not always allow the length of the embossed stretches to be calculated to an adequate degree of precision.

Moreover, having to provide the processing unit with the phase signal relating to the real cutting position makes it necessary to use an electronic system capable of responding sufficiently quickly to ensure an accurate result. Consequently, the prior art device is relatively expensive.

Further information that could be useful to better understand the scope of the present application can be found in the following documents: <CIT>, that discloses a method for operating a manufacturing machine of rod-shaped articles having an embossed wrapping strip where the quality or position of the embossing is determined based on the digitized image data of the rod-shaped article; <CIT>, that discloses a smoking article assembly machine comprising a microwave sensor unit configured to provide an indication of one or more properties of a filter rod; and <CIT>, that discloses a method for producing rod-shaped products in the tobacco processing industry each covered by a wrapping strip having a perforation pattern whose realization is monitored by cameras.

This invention has for an aim to provide a device, a method and an apparatus for inspecting embossed filter segments to overcome the above mentioned drawbacks.

The above aim is achieved by a device, a method and an apparatus for inspecting embossed filter segments as claimed respectively in claims <NUM>, <NUM> and <NUM>.

The invention is described below with reference to the accompanying drawings, which illustrate non-limiting embodiments of it, and in which:.

With reference to the accompanying drawings, the numeral <NUM> generically denotes a device for inspecting embossed filter segments.

An embossed filter segment <NUM> is a cylindrical element extending longitudinally along an axis of extension X. An embossed filter segment <NUM> may be coupled, for example, to a tobacco segment to make a smoking article.

An embossed filter segment <NUM> is usually obtained from an embossed filter rod <NUM>, the embossed filter rod <NUM> being in turn obtained by wrapping a rod of filter material <NUM> first in a tape of embossed tipping paper <NUM> and then in a tape of smooth tipping paper <NUM>. More in detail, the tape of embossed tipping paper <NUM> is a tape which extends longitudinally and which has portions of embossed tape, transverse to the extension of the tape and alternated with portions of non-embossed (or smooth) tape.

With reference to <FIG>, a production machine <NUM> for making embossed filter segments <NUM> comprises:.

The second wrapping station <NUM> may be located downstream of the first wrapping station <NUM>. Alternatively, the first wrapping station <NUM> and the second wrapping station <NUM> may substantially coincide so that the tape of embossed tipping paper <NUM> and the tape of tipping paper <NUM> are applied to the rod of filter material <NUM> substantially simultaneously.

The term "embossed filter segment" may be used to mean a piece of embossed filter <NUM> equal in length to the filter tip of a smoking article. Alternatively, the term "embossed filter segment" may be used to mean a piece of embossed filter which is twice the length of the filter tip of a smoking article.

<FIG> schematically illustrate different embodiments of an embossed filter segment <NUM>.

Generally speaking, an embossed filter segment <NUM> comprises at least a first portion <NUM> and a second portion <NUM>, each having a first end 20a, 21a and a second end 20b, 21b. The second end 20b of the first portion <NUM> is adjacent and contiguous to the first end 21a of the second portion <NUM>. Further, the first portion <NUM> or the second portion <NUM> is embossed.

With reference to <FIG>, the embossed filter segment <NUM> illustrated has a first portion <NUM> which is embossed and a second portion <NUM> which is not embossed.

With reference to <FIG> and <FIG>, the embossed filter segment <NUM> illustrated has a first portion <NUM> which is embossed, a second portion <NUM> which is not embossed and third portion <NUM> which is embossed and is contiguous and adjacent to the second portion <NUM>.

With reference to <FIG>, the embossed filter segment <NUM> illustrated has a first portion <NUM> which is not embossed, a second portion <NUM> which is embossed and third portion <NUM> which is not embossed and is contiguous and adjacent to the second portion <NUM>.

With reference to <FIG>, the embossed filter segment <NUM> illustrated has a first portion <NUM> which is not embossed, a second portion <NUM> which is embossed and third portion <NUM> which is embossed; the first portion <NUM> is disposed between the second portion <NUM> and the third portion <NUM>.

With reference to <FIG>, the embossed filter segment <NUM> illustrated has a first portion <NUM> which is embossed, a second portion <NUM> which is not embossed and third portion <NUM> which is not embossed; the first portion <NUM> is disposed between the second portion <NUM> and the third portion <NUM>.

Described below with reference to <FIG> is an embodiment of the device <NUM> of this invention for inspecting embossed filter segments <NUM>.

The device <NUM> comprises: a drum <NUM> rotatable about a rotation axis Y and comprising a plurality of seats <NUM> for receiving in each one an embossed filter segment <NUM>; image capturing means <NUM> for capturing an image of a first part <NUM> of the embossed filter segment <NUM> disposed in the seat of the drum <NUM>, the first part <NUM> extending parallel to the axis of extension X of the embossed filter segment <NUM> and at least from the first end 20a of the first portion <NUM> to the first end 21a of the second portion <NUM>; a processing unit <NUM> for processing the aforesaid image and which, based on the image, calculates the length L<NUM> of the first portion <NUM> of the embossed filter segment <NUM>. By "length L<NUM> of the first portion <NUM> of the embossed filter segment <NUM>" is meant the length of the first portion <NUM> in the direction of the axis of extension X.

The proposed device <NUM> captures the image of the first part <NUM> of the embossed filter segment <NUM> while the latter is being held in the seat <NUM> of the drum <NUM>. For this purpose, the drum <NUM> may comprise suction means which hold the embossed filter segments <NUM> in the respective seats <NUM>. In any case, the embossed filter segment <NUM> is stable and the image captured is such as to allow the length L<NUM> to be calculated accurately.

The first part <NUM> of the embossed filter segment <NUM> whose image is captured extends preferably longitudinally. In other words, the first part <NUM> of the embossed filter segment <NUM> is greater in length in the direction parallel to the axis of extension X than it is in height in the direction at right angles to the axis of extension X.

More specifically, the image captured of the first part <NUM> of the embossed filter segment <NUM> is an image from the front (this image being at most equal to <NUM> degrees of the circle of the embossed filter segment <NUM>; preferably, the image is equal to <NUM> degrees of the circle of the embossed filter segment <NUM>).

The drum <NUM> can receive the embossed filter segments <NUM> from the above described production machine <NUM> for making embossed filter segments <NUM>. In such a case, the processing unit <NUM> can be connected to the cutting means <NUM> and/or to the embossing means <NUM> of the production machine <NUM> which makes embossed filter segments <NUM>, so as to drive the cutting means <NUM> and/or the embossing means <NUM> on the basis of the calculated length L<NUM>.

Advantageously, since the inspection is performed on the embossed filter segment <NUM> (and not on the filter rod), a phase signal indicating the real position of the cut is not necessary. Consequently, the proposed device <NUM> with feedback control can be implemented with traditional electronic circuitry, advantageously allowing costs to be limited.

Further, the proposed device <NUM> may comprise rejection means <NUM> which are connected to the processing unit <NUM> and which are driven by the processing unit <NUM> to reject the embossed filter segments <NUM> on the basis of the calculated length L<NUM> (<FIG>).

With reference in particular to <FIG>, the image capturing means <NUM> comprise a first camera <NUM> which captures the image of the first part <NUM> of the embossed filter segment <NUM> disposed in the seat <NUM> of the drum <NUM>.

The image capturing means <NUM> may also comprise a first illuminator <NUM> which illuminates at least the aforesaid first part <NUM> of the embossed filter segment <NUM> disposed in the seat <NUM> of the drum <NUM>.

Advantageously, illuminating the first part <NUM> allows capturing a clearer image so that the length L<NUM> can be calculated more accurately.

The first camera <NUM> and the first illuminator <NUM> are driven in phase, or simultaneously.

Preferably, the first camera <NUM>, the first illuminator <NUM> and the drum <NUM> are mutually disposed so that, during image capture, the embossed filter segment <NUM> is positioned between the first camera <NUM> and the first illuminator <NUM>.

Thus, during image capture, the light from the illuminator <NUM> passes through at least the first part <NUM> of the embossed filter segment <NUM> so as to allow capturing a clear image. More specifically, by processing the image it is possible to accurately calculate the length L<NUM> of the first portion <NUM> of the embossed filter segment <NUM>. Also, the fact that the light passes through the first part <NUM> of the embossed filter segment <NUM> makes it possible to inspect internal features, that is, those below the surface of the embossed filter segment <NUM>.

The image capturing means <NUM> may also comprise a first diaphragm <NUM> between the first camera <NUM> and the first illuminator <NUM>. Advantageously, the light from the first illuminator <NUM> is concentrated on the first part <NUM> of the embossed filter segment <NUM>.

With reference in particular to <FIG>, each seat <NUM> of the drum <NUM> is configured to receive only partially the embossed filter segment <NUM> so that at least the first part <NUM> of the embossed filter segment <NUM> protrudes from the drum <NUM>. In such a case, the first camera <NUM> and the first illuminator <NUM> are counterposed to each other and side by side with the drum <NUM>. This arrangement of first camera <NUM> and first illuminator <NUM> allows using a drum <NUM> of a kind well known in the tobacco industry. Consequently, this solution is simple in construction and inexpensive.

Alternatively, in an embodiment not illustrated and not covered by the claims, the first illuminator or the first camera is disposed at least partly inside the first drum (preferably, the first illuminator is disposed at least partly inside the drum). In such a case, each seat of the drum is shaped to allow the passage of the light at least at the aforesaid first part <NUM> of the embossed filter segment <NUM> (for example, the seat of the drum may be made of a transparent material or it may be formed in a slit, slot or opening in the drum. Advantageously, this embodiment of the device <NUM> is particularly compact.

With reference to the embodiments of the embossed filter segments <NUM> illustrated in <FIG>, the embossed filter segment <NUM> comprises a third portion <NUM> having a first end 22a, which is adjacent and contiguous to the second end 21b of the second portion <NUM>, and a second end 22b. More specifically, if the first portion <NUM> is embossed, then the third portion <NUM> is also embossed; if the first portion <NUM> is smooth (that is, not embossed), then the third portion <NUM> is also smooth.

The image capturing means <NUM> may be configured to capture an image of a second part <NUM> of the embossed filter segment <NUM> disposed in the seat <NUM> of the drum <NUM>, the second part <NUM> being counterposed to the first part <NUM> and extending parallel to the axis of extension X of the embossed filter segment <NUM> at least from the second end 22b of the third portion <NUM> to the second end 21b of the second portion <NUM>.

In such a case, the second part <NUM> is diametrically opposite to the first part <NUM> and offset, in the direction of extension of the embossed filter segment <NUM>, relative to the first part <NUM> (<FIG>). Alternatively, the second part <NUM> might be facing and diametrically opposite to the first part <NUM>.

An embossed filter segment <NUM> comprises a splice line on the tape of tipping paper <NUM> wrapped around the rod of filter material <NUM>; the splice line is parallel to the direction of extension of the embossed filter segment <NUM>. Consequently, if the image captured is at the splice line, it might be complicated to calculate the length L<NUM> to an adequate degree of precision. Advantageously, capturing an image both of the first part <NUM> and the second part <NUM> ensures that the length L<NUM> can be calculated accurately.

With reference to the embodiment of the embossed filter segment <NUM> illustrated in <FIG>, the second part <NUM> is counterposed (that is, diametrically opposite) to the first part <NUM> and extends parallel to the axis of extension X of the embossed filter segment <NUM> at least from the first end 20a of the first portion <NUM> to the first end 21a of the second portion <NUM> (<FIG>). In such a case, the second part <NUM> might be counterposed to the first part <NUM>, that is, facing and diametrically opposite to the first part <NUM>.

Alternatively, the second part <NUM> may extend at least from the second end 20b of the first portion <NUM> to the second end 21b of the second portion <NUM>. In such a case, the second part <NUM> is diametrically opposite to the first part <NUM> and offset, in the direction of extension X, relative to the first part <NUM>.

The second part <NUM> of the embossed filter segment <NUM> whose image is captured extends preferably longitudinally. In other words, the second part <NUM> of the embossed filter segment <NUM> is greater in length in the direction parallel to the axis of extension X than it is in height in the direction at right angles to the axis of extension X.

More specifically, the image captured of the second part <NUM> of the embossed filter segment <NUM> is an image of the second part <NUM> from the front (this image being at most equal to <NUM> degrees of the circle of the embossed filter segment <NUM>; preferably, the image is equal to <NUM> degrees of the circle of the embossed filter segment <NUM>).

In this embodiment, in which the image of the second part <NUM> is captured, the image capturing means <NUM> comprise: a second camera which captures the image of the second part <NUM> of the embossed filter segment <NUM> disposed in the seat <NUM> of the drum <NUM>; a second illuminator which illuminates at least the second part <NUM> of the embossed filter segment <NUM> disposed in the seat <NUM> of the drum <NUM>.

The second camera and the second illuminator are driven in phase, or simultaneously. The image capturing means <NUM> may also comprise a second diaphragm between the second camera and the second illuminator. Advantageously, the light from the second illuminator is concentrated on the second part <NUM> of the embossed filter segment <NUM>.

With reference in particular to <FIG>, the production machine <NUM> for making embossed filter segments can make two embossed filter rods and feeds out pairs of embossed filter segments <NUM>. In such a case, the device <NUM> may comprise a pair of (counter-rotating) conveyor drums - a first drum <NUM> and a second drum <NUM> - each of which receives one embossed filter segment <NUM> of the pair of embossed filter segments <NUM> feeding out of the machine <NUM>. The first conveyor drum <NUM> transfers the embossed filter segments to the drum <NUM> on which at least the image of the first longitudinal portion <NUM> of the embossed filter segment <NUM> is captured.

The second conveyor drum <NUM> transfers the embossed filter segments <NUM> to a further drum <NUM>, which is similar to the drum <NUM> and near which there is at least one camera <NUM> and one illuminator <NUM> to capture an image of at least a first longitudinal portion of the embossed filter segment <NUM> disposed in the seat of the drum <NUM>.

According to the embodiment of the device <NUM> illustrated in the drawings, the spacing between the seats <NUM> on the drum <NUM> is double the spacing between the seats on the drum <NUM>; the device <NUM> may comprises further conveyor drums <NUM>, <NUM> (for example, two) disposed between the drum <NUM> and the further drum <NUM> to transfer the embossed filter segments <NUM> from the drum <NUM> to the further drum <NUM>.

Described below is a method according to this invention for inspecting embossed filter segments <NUM>. In particular, the method can be implemented by any of the embodiments of the device <NUM> described above.

The embossed filter segment <NUM> may be disposed in the seat <NUM> of the drum <NUM> by a production machine <NUM> which makes embossed filter segments <NUM>, the machine <NUM> comprising embossing means <NUM> for embossing a tape of tipping paper and cutting means <NUM> for cutting an embossed filter rod <NUM> to obtain embossed filter segments <NUM>. Preferably, the method comprises the step of driving the cutting means <NUM> and/or the embossing means <NUM> of the production machine <NUM> which makes embossed filter segments <NUM>, on the basis of the calculated length L<NUM>.

Advantageously, an adequate length L<NUM> of the first portion <NUM> of the embossed filter segment <NUM> is ensured at all times. Furthermore, compared to the prior art, this method can be implemented easily and with inexpensive electronic circuitry, since the inspection is performed on the embossed filter segment <NUM> (and not on the filter rod) and a phase signal indicating the real position of the cut is not therefore necessary.

The method may also comprise the step of comparing the calculated length L<NUM> with a reference value. This step may be performed before the step of driving the cutting means <NUM> and/or the embossing means <NUM> of the production machine <NUM> which makes embossed filter segments <NUM>, on the basis of the calculated length L<NUM>.

The method may also comprise the step of rejecting the embossed filter segments whose length L<NUM> differs from the reference value; preferably, this step is performed after the step of comparing the calculated length L<NUM> with a reference value.

According with the invention, the step of capturing the image of the first part <NUM> of the embossed filter segment <NUM> comprises the step of illuminating the first part <NUM> of the embossed filter segment <NUM>. More specifically, the step of illuminating the first part <NUM> of the embossed filter segment <NUM> is performed in such a way that the light passes through the first part <NUM>.

Advantageously, the image captured is particularly clear.

If the embossed filter segment <NUM> comprises a third portion <NUM> having a first end 22a, which is adjacent and contiguous to the second end 21b of the second portion <NUM>, and a second end 22b, and if the third portion <NUM> is embossed only if the first portion <NUM> is embossed, then the method may comprise the step of capturing an image of a second part <NUM> of the embossed filter segment <NUM>. The second part <NUM> is counterposed to the first part <NUM> and extends parallel to the axis of extension X of the embossed filter segment <NUM> at least from the second end 22b of the third portion <NUM> to the second end 21b of the second portion <NUM>.

Thus, since the tape of tipping paper <NUM> wrapped around the rod of filter material <NUM> to form the embossed filter segment <NUM> has a splice line on it which is parallel to the direction of extension of the embossed filter segment <NUM>, capturing the image both of the first part <NUM> and of the second part <NUM> ensures that the length L<NUM> can be calculated accurately.

Alternatively, the second part <NUM> might be facing and diametrically opposite to the first part <NUM>.

With reference to the embodiment of the embossed filter segment <NUM> illustrated in <FIG>, the second part <NUM> is counterposed (that is, diametrically opposite) to the first part <NUM> and extends parallel to the axis of extension X of the embossed filter segment <NUM> at least from the first end 20a of the first portion <NUM> to the first end 21a of the second portion <NUM> (<FIG>). In such a case, the second part <NUM> might be counterposed to the first part <NUM>, that is, facing and diametrically opposite to the first part <NUM>. Alternatively, the second part <NUM> may extend at least from the second end 20b of the first portion <NUM> to the second end 21b of the second portion <NUM>. In such a case, the second part <NUM> is diametrically opposite to the first part <NUM> and offset, in the direction of extension X, relative to the first part <NUM>.

Preferably, the step of capturing the image of the second part <NUM> of the embossed filter segment <NUM> comprises the step of illuminating the second part <NUM> of the embossed filter segment <NUM>. Further, the step of illuminating the second part <NUM> of the embossed filter segment <NUM> is preferably performed in such a way that the light passes through the second part <NUM>.

Claim 1:
A device (<NUM>) for inspecting embossed filter segments (<NUM>), where each embossed filter segment (<NUM>) extends longitudinally along an axis of extension (X) and comprises at least a first portion (<NUM>) and a second portion (<NUM>) each having a first end (20a, 21a) and a second end (20b, 21b); the second end (20b) of the first portion (<NUM>) being adjacent and contiguous to the first end (21a) of the second portion (<NUM>); the first portion (<NUM>) or the second portion (<NUM>) being embossed;
the device (<NUM>) being characterized in that it comprises:
a drum (<NUM>) rotatable about a rotation axis (Y) and comprising a plurality of seats (<NUM>) for receiving in each one an embossed filter segment (<NUM>);
image capturing means (<NUM>) for capturing an image of a first part (<NUM>) of the embossed filter segment (<NUM>) disposed in the seat of the drum (<NUM>), the first part (<NUM>) extending parallel to the axis of extension (X) of the embossed filter segment (<NUM>) and at least from the first end (20a) of the first portion (<NUM>) to the first end (21a) of the second portion (<NUM>);
a processing unit (<NUM>) for processing the aforesaid image and which, based on the image, calculates the length (L<NUM>) of the first portion (<NUM>) of the embossed filter segment (<NUM>);
wherein the image capturing means (<NUM>) comprise: a first camera (<NUM>) which captures the image of the first part (<NUM>) of the embossed filter segment (<NUM>) disposed in the seat (<NUM>) of the drum (<NUM>); a first illuminator (<NUM>) illuminating at least the first part (<NUM>) of the embossed filter segment (<NUM>) disposed in the seat (<NUM>) of the drum (<NUM>).
wherein each seat (<NUM>) of the drum (<NUM>) is configured to receive only partially the embossed filter segment (<NUM>) so that at least the first part (<NUM>) of the embossed filter segment (<NUM>) protrudes from the drum (<NUM>); the first camera (<NUM>) and the first illuminator (<NUM>) are counterposed to each other and side by side with the drum (<NUM>).