METHOD AND DEVICE FOR TRANSFERRING ROD-SHAPED

ARTICLES

Technical field

This invention relates to a method and a device for transferring rod shaped articles, specifically (but not limited to) rod-shaped articles of the tobacco industry. More specifically, this invention regards the transferring of articles between a flow advancing transversely to the articles themselves to a flow advancing axially.

Background art

Known at present in the tobacco industry is the use of specific rotary conveyors (known as “spiders”) at a zone of intersection between a flow of articles advancing transversely and a flow of articles advancing axially. These rotary conveyors are provided with working units which pivot about respective axes to receive incoming articles from a flow of articles moving transversely and to deliver the articles to a flow moving axially.

These conveyors are based on the idea of delivering each article to an axial flow, specifically to a longitudinal groove of a forming beam, by placing each article in such a way that it is aligned with the article delivered previously and advancing along the beam.

In the case of very long compositions, the prior art also teaches the practice of dividing the compositions into two parts and in such a case, the succession of articles advancing transversely is defined by a succession of first units and second units, where each first and second unit are consecutive with each other and define a respective composition (hence one article) in the beam. In some circumstances, such “long” compositions are not divisible into two units of equal length and, for this reason, the succession of articles advancing transversely is defined by a succession of first, long units and second, short units.

A situation such as this calls for a transfer device (spider) having an even number of working units mounted in alternate (long and short) succession to match the order in which the respective units make up the composition. Disadvantageously, these transfer devices are complex and must necessarily have an even number of working units.

Disclosure of the invention

In this context, the basic technical purpose of this invention is to provide a method and a device for transferring rod-shaped articles to overcome the above mentioned disadvantages of the prior art.

More specifically, this invention has for an aim to provide a method and a device for transferring rod-shaped articles offering a high level of flexibility for choosing the number of working units, in particular in situations where the succession of articles to be transferred is a succession of long and short units.

Another aim of the invention is to provide a method and a device for transferring rod-shaped articles and which are characterized by high simplicity of embodiment.

The technical purpose indicated and the aims specified are substantially achieved by a method and a device for transferring rod-shaped articles comprising the technical features described in claims 1 and 6, respectively, and/or in one or more of the appended claims.

Brief description of the drawings

Further features and advantages of the invention are more apparent in the indicative, hence non-limiting, description of a preferred but non-exclusive embodiment of a method and a device for transferring rod-shaped articles, as illustrated in the accompanying drawings, in which:

- Figure 1 is a front view of a transfer device according to the invention;

- Figure 1 A is a view of a detail of the device of Figure 1 ;

- Figure 2 is a schematic view of two articles moved by the transfer device according to the invention;

- Figure 3 is a full schematic view of an assembling machine comprising the device of Figure 1 ;

- Figures 4-6 show further embodiments of two articles which are suitable for being moved by the transfer device according to the invention.

Detailed description of preferred embodiments of the invention

The numeral 1 in the accompanying drawings denotes in its entirety a device for transferring rod-shaped articles according to this invention.

In the context of this invention, by “rod-shaped articles” is meant articles with an elongated cylindrical shape and preferably circular cross section, defined in particular by one or more segments which may, if necessary, have different properties or be of different kinds. For example, an article according to the invention may be a composition of filter segments or a single filter segment or a succession of segments of one or more of the following kinds: filter segments; tubular segments; tobacco segments; segments of heating material, and others still. The specific nature of the segments, however, does not limit the scope of this invention, which is characterized by the mode of operation and the structure and not the kind of articles transferred. For the same reason, therefore, the invention applies both to machines of the tobacco industry and, more generally speaking, to machines for making aerosol generating articles or the like and, more specifically, applies to assembling machines, whose structure will be described below.

The device 1 essentially comprises feed means 10 for feeding an alternating succession of first and second rod-shaped articles 11 , 12 along a direction perpendicular to the longitudinal axis of the articles 11 , 12, a forming beam 20 and a rotary transfer means 30 interposed between the feed means 10 and the forming beam 20. The rotary transfer means 30 comprises a platform 31 (or other means suitable for the purpose, such as a wheel, for example) which is rotatable about a horizontal axis X and which is provided with a plurality of working units 32 which are movable along a closed feed path which passes through a pickup station P, where each working unit 32 picks up a corresponding article 11 , 12 from the feed means 10 with a transverse movement, and a release station R, where each working unit 32 releases the corresponding article 11 , 12 on the forming beam 20 with an axial movement.

The general structure of the transfer means 30 is known and will not therefore be described in detail. It is noted, however, that a particular feature of the transfer means 30 is that it causes the working units 32 to move along a closed feed path, preferably circular. Thus, between the pickup stations P and the release stations R, each working unit 32 follows a curved trajectory, corresponding preferably to a circular arc. Further, the working units 32 are pivotable in controlled manner about respective pivoting axes parallel to the axis X of the platform 31 which is rotatable so that the working units keep the same orientation. Since each working unit 32 has at the bottom of it a seat that holds a respective article 11 , 12 by pneumatic suction, the orientation of the article 11 , 12 also remains the same along the feed path and, in particular, the horizontal feed path. In other words, each working unit 32 is subjected to a movement by translation only along a curved trajectory defined by the closed feed path.

In the embodiment of Figure 1 , the transfer means illustrated is, for clarity of illustration, provided with only eight working units 32; there may, however, be a much higher number of working units, depending on requirements (for example, up to 30 or even more). Upstream of the transfer means 30 there is a drum 40 with orientable arms, also of known structure, forming part of the feed means 10 and defining the last drum in a sequence of drums for transversely feeding the articles 11 , 12. The drum 40 with orientable arms acts in conjunction with the transfer means 30 to transfer the articles 11 , 12 to a zone of tangency. Upstream of the drum 40 with orientable arms, the feed means 10 also comprise an assembling unit 50 (Figure 3), of per se known type and comprising a plurality of feed lines 51 , 52, 53, 54 for feeding respective successions of segments, and a conveying device 55 configured to receive and assemble the segments fed by the feed lines 51 , 52, 53, 54 to obtain the alternating succession of articles 11 , 12. Preferably, the assembling unit 50 makes up and disposes the articles 11 , 12 so they are centrally aligned, as shown in Figure 2. By “centrally aligned” is meant, in other words, that the plane that divides the respective article 11 , 12 into two equal parts coincides with the plane that divides into two equal parts the article 11 , 12 that precedes it or follows it.

In a particular application of the method and device according to the invention, the articles 11 , 12 fed by the feed means 10 differ in length and, more specifically, may be defined by different combinations of segments (one of the many possible embodiments is shown in Figure 2).

In the embodiment illustrated, the first article 11 has a first length L1 , while the second article 12 has a length L2, different from L1 , and is made up of a different sequence of segments.

Figures 4-6 show embodiments in which the articles may include a combination of segments and empty spaces.

More specifically, Figure 4 shows an embodiment in which the first article 11 is defined by a succession of rod-shaped segments, whilst the second article 12 is defined by one rod-shaped segment with two empty spaces at the ends of it. In this case, when the first and second articles 11 , 12 are released in sequence onto the forming beam 20, the continuous rod that is formed is provided with empty spaces suitable, for example, for making cavities to contain filling materials or for making spacing stretches.

In the specific embodiment of Figure 4, the second article 12, in particular, has two spaces at the ends of it and at least one central segment which is preferably centred at the centre line of the article 12.

With reference to the embodiment of Figure 5, the first article 11 corresponds to the first article 11 of Figure 4 but has a space at one end of it, corresponding to one of the two spaces of the article of Figure 4, whilst the second article 12 has only one space adjacent to one rod-shaped segment (or sequence of segments).

With reference to the embodiment of Figure 6, the first article 11 corresponds to the first article 11 of Figure 5, but with the space reversed in position, that is to say, at the opposite end.

Advantageously, the working units 32 of the transfer means 30 are separated from each other by a linear distance D, measured along the feed path of the working units 32 (Figure 1A), adjusted and/or selected as a function of the mean length l_ _m of the first and second articles 11 , 12. The distance D is the same for all the pairs of consecutive working units 32, meaning that they are equispaced around the axis X of the transfer means 30. In other words, the distance D is a function of the mean length Lm of the first and second articles 11 , 12.

More in detail, the mean length L _m of the first and second articles 11 , 12 can be calculated with the following formula:

Preferably, the distance D coincides with the mean length L _m .

If necessary, based on the kind of articles, the mean length Lm of the first and second articles 11 , 12 as calculated above might include adding a corrective factor.

The distance D according to this criterion is measured in particular at the pivoting axes of the individual working units 32 and allows setting a uniform spacing between the working units 32, irrespective of whether they receive the first articles 11 or the second articles 12 of different lengths. In effect, even in such a situation, the excess part of the length of the longest article relative to the mean length L _m compensates for the empty space left when the shorter (preceding or following) consecutive article, is released.

In an embodiment, this also allows having an uneven number of working units 32. It is understood that this solution is possible even when there is an even number of working units 32.

In use, the feed means 10 feed the alternating succession of first and second articles 11 , 12 along a direction perpendicular to the longitudinal axis of the articles 11 , 12 and the individual articles 11 , 12 are picked up from the alternating succession (specifically by the drum 40 with orientable arms) by respective working units 32 of the transfer means 30 at the pickup station P, while the articles 11 , 12 are advancing with transverse motion, and are released by the working units 32 onto the forming beam 20 at the release station R while the articles 11 , 12 are advancing with longitudinal motion, forming a continuous rod 100. The rod 100, in the customary manner, is then wrapped in a web, preferably of paper, and cut into individual products sent on for further processing.

During the step of releasing, each article 11 , 12 is lined up behind the article 11 , 12 released before on the beam 20 and, thanks to the specific distance between the working units 32, each article 11 , 12 is placed exactly end to end with the preceding article without interfering with or impacting against it, or is released by defining the corresponding spaces of the correct lengths, where provided.