WO2017036911A1

WO2017036911A1 - Improved apparatus for combining filter components

Info

Publication number: WO2017036911A1
Application number: PCT/EP2016/070063
Authority: WO
Inventors: Diego Ferrazzin; Luciano DI DOMENICO; Niki MELONCELLI; Stefano Sorghi
Original assignee: Philip Morris Products S.A.
Priority date: 2015-08-28
Filing date: 2016-08-25
Publication date: 2017-03-09

Abstract

An apparatus for handling filter rod segments for smoking articles comprises a rotating drum having flutes on a peripheral surface of the drum, the flutes for receiving filter rod segments as the drum rotates and for conveying the filter rod segments to an output station; and a transfer assembly for receiving at least a filter rod segment at the output station and for advancing the filter rod segments from the output station in a first conveyance direction extending parallel to an axial direction of the drum. A transverse cross section of the flutes is substantially cup-shaped and symmetrical with respect to a radial drum direction defining a plane (X) of substantial symmetry of the flute. A receiving surface of each flute contacts the outer surface of the at least one filter rod segment at least at two points separated by at least about 150degrees about the periphery of the at least one filter rod segment.

Description

IMPROVED APPARATUS FOR COMBINING FILTER COMPONENTS

The present invention relates to an apparatus for handling filter rod segments for use in the manufacture of smoking articles such as filter cigarettes.

Filter cigarettes typically comprise a rod of tobacco cut filler surrounded by a paper wrapper and a cylindrical filter aligned in end-to end relationship with the wrapped tobacco rod and attached thereto by tipping paper. Several filters for smoking articles are known that comprise a plurality of cylindrical components attached in axial alignment. By way of example, methods are known for manufacturing a filter for a smoking article comprising two or three different segments.

In the manufacture of such multi-component filters, one or more of the components may be initially provided as a double or quadruple length component, that is, a component which is two or four times the length of that component in the final smoking article. These multiple-length rods are typically cut and separated into smaller portions and other components introduced between the cut portions. The various segments within a filter must usually be placed in a particular order and arrangement, such that consecutive segments are in abutting relationship or aligned with one another at a predetermined distance from each other, for example to define an internal cavity of the filter.

The complex combining procedure is carried out on machinery known as a combiner. A conventional combiner generally comprises a plurality of rotating drums. The circumferential surfaces of the drums have axially aligned channels, for example grooves or notches, often referred to as 'flutes', for receiving the cylindrical components of the smoking article to be manufactured.

Distinct filter segments are formed by cutting filter rods with cutters operatively coupled with different drums as the filter rods move about their respective drum peripheries. The cut filter segments may be removed from each drum with a transfer assembly that comprises a linear conveyor, such as a driving chain, which extends in the axial direction of the drum and engages a filter segment comprised in one flute of the drum. Thus, the linear conveyor is adapted to convey the filter segments along a first conveyance direction which extends substantially parallel to an axial direction of the drum, along the flutes. In the transfer assembly, the linear conveyor is further operatively coupled with stationary guide means for maintaining the orientation of the axis of the filter segments removed from the flutes of the drum in the first conveyance direction. One such assembly of linear conveyor and stationary guide means is known, for example, from WO 2013/013738.

The transfer assembly known from WO 2013/013738 further comprises a conveyance disc located downstream from the linear conveyor and adapted to engage the filter segments and to transport them along a curving conveyance direction. For example, the conveyance disc may be adapted to progressively change the conveyance direction of the filter segments by about 90 degrees. To this purpose, the conveyance disc is generally operatively coupled with curved guiding means such that a curved channel is defined between a reference surface of the curved guiding means and the conveyance disc. Further, the conveyance disc is typically provided with a plurality of fingers arranged about the periphery of the disc and distanced from one another such that a predetermined gap is created between consecutive filter segments.

When handling short filter segments, that is, filter segments having a length of less than about 6 mm, it may be difficult for the existing equipment to provide for the accurate transfer of the filter segments. In particular, whenever a short filter segment disengages from one moving component of the transfer device to engage another moving component of the transfer device, such as when a filter segment is passed from the drum to the linear conveyor, or from the linear conveyor to the conveyance disc, it may be difficult to control precisely the correct positioning of a short filter segment. In addition, because these filter segments have an aspect ratio, that is a length-to-diameter ratio, very close to (1 :1 ), their longitudinal axes have a tendency to become misaligned with respect to the longitudinal axes of the respective flutes.

This may make their transfer completely impossible, if they become stuck in a flute, or it can cause further issues when they are handed over to the transfer assembly downstream of the drum, since the short filter segments may then become stuck at any location along their transfer path or, not be aligned with the other components of the filter. This is clearly undesirable, because the correct spacing and alignment between filter segments leaving the combiner is critical for the subsequent operations in the filter making process.

Therefore, it would be desirable to provide an apparatus for handling filter rod segments for use in the manufacture of smoking articles whereby the handling of short filter rod segments is made easier and the correct positioning and mutual spacing of the filter rod segments leaving the apparatus is more consistently and efficiently controlled. Further, it would be desirable to provide one such apparatus that does not require a major modification of the existing apparatus and that is, therefore, relatively simple and inexpensive.

According to an aspect of the present invention, there is provided an apparatus for handling filter rod segments for use in the manufacture of smoking articles. The apparatus comprises a rotating drum having at least one flute on a peripheral surface of the drum. The at least one flute extends longitudinally along an axis (F) parallel to a rotation axis of the drum and is adapted, as the drum rotates, to receive a filter rod segment and to convey the filter rod segment to an output station. Further, the apparatus comprises a transfer assembly for receiving the filter rod segment at the output station and for advancing the filter rod segment from the output station in a first conveyance direction extending substantially parallel to the rotation axis of the drum. When seen in a transverse cross section, a receiving surface of the at least one flute is substantially symmetrical with respect to a radial plane (X) of the drum, such that the receiving surface of the flute contacts the outer surface of the filter rod segment at least at two points separated by at least about 150 degrees about the periphery of the filter rod segment.

According to a further aspect of the present invention, there is provided a method of handling filter rod segments for use in the manufacture of smoking articles. The method comprises conveying a filter rod segment in at least one elongate holding means. Further, the method comprises removing the filter rod segment from the at least one holding means and advancing the filter rod segment along a first conveyance direction substantially parallel to an axial direction of the holding means. Advancing the filter rod segment comprises maintaining the orientation of the axis of the filter segment in the first conveyance direction by means of stationary guide means. In addition, the method comprises transporting the filter rod segment along a curving conveyance direction to bring the orientation of the axis of the filter rod segment from the first conveyance direction to a second conveyance direction; and moving the filter rod segment to adjust the orientation of the axis of the filter rod segment from the first conveyance direction to the curving conveyance direction by engaging the filter rod segment with a moving surface of a motorised moving means.

It will be appreciated that any features described with reference to one aspect of the present invention are equally applicable to any other aspect of the invention.

In an apparatus according to the present invention, a rotating drum is provided having one or more flutes on an exterior surface of a drum. When a plurality of flutes are provided, they are spaced apart about the periphery of the drum. The flutes are constructed and arranged to receive filter rod segments as the drum rotates and to convey the filter rod segments to an output, where a transfer assembly receives at least one filter rod segment and advances the at least one filter rod segment from the output in a first conveyance direction substantially parallel to an axial direction of the drum. In contrast to known apparatus, the receiving surface of the one or more flutes, when seen in a transverse cross section, is substantially symmetrical with respect to a radial plane of the drum, and the receiving surface of the flute is constructed and adapted to contact the outer surface of the filter rod segment received within the flute at least at two points separated by at least about 150 degrees about the periphery of the filter rod segment.

By providing the apparatus with a rotating drum that presents one such modified flute profile, the contact area between the flute surface and the filter rod segment is increased and the filter rod segment is more safely and stably held within the flute. Thus, it is much easier to maintain a longitudinal axis of the filter rod segment in alignment with a longitudinal axis of the flute during transportation of the filter rod segment about the periphery of the drum. This is particularly advantageous when short filter rod segments, particularly filter rod segments having an aspect ratio close to (1 :1 ) are handled, since it is thus easy to prevent them from becoming stuck within a flute or misaligned with the flute and, as a consequence, with the first conveyance direction of the transfer assembly.

Accordingly, the correct positioning and mutual spacing of the filter rod segments downstream of the rotating drum can be more consistently and efficiently controlled. As shall become apparent from the following description, in some preferred embodiments it is also advantageously easy to further maintain the correct alignment of the filter rod segment as it is advanced forward by the transfer assembly. Advantageously, this does not require a major modification of existing apparatus and is, therefore, relatively simple and inexpensive to implement.

The term "filter rod segment" is used throughout the specification to refer to a segment of a filter rod that may form a part of or be the entire filter for a smoking article. The filter segment may also comprise the filter elements of more than one filter, that is, a rod of multiple filter elements that is subsequently severed into shorter filter rod segments. Typically, one such filter rod has the length of two or four filters of the final smoking article. Examples for filter segments are, without limitation, plain filter tow plugs or filter tow plugs with additional elements like, for example, beads, capsules, plant material or threads disposed in the filter material. Further examples for filter rod segments are non-cuttable objects like, for example, restrictor elements or tubular elements. Further examples for filter segments are plugs comprising other non-tow material, like for example, plant material, beads, capsules or granules or combinations thereof. The segments may also be combinations of two to five individual filter elements, like for example a double filter segment comprising a plain filter tow segment and a filter tow segment with carbon beads. The segments may also be combination of filter segments as above with "void" elements, that is, segments that are empty, like for example a so called plug-space-plug filter or a filter with a mouth-end cavity. For the avoidance of doubt, the term "filter" is used to refer to the location of the filter segment in the filter portion of the smoking article without making a reference of the possible filtration effect of such a filter segment.

In the present specification, the term "substantially symmetrical" is used to describe the profile of the groove or notch forming a flute of a rotating drum, and, more particularly, the portion of the surface of the groove or notch that, in use, comes into contact with a filter rod segment. This surface is also referred to as "the receiving surface" of the flute.

In general, in accordance with the present invention, each flute on the peripheral surface of the drum is "substantially symmetrical" with reference to a respective "plane of substantial symmetry". For each flute, a "plane of substantial symmetry" is the radial drum plane that intersects the receiving surface of the drum at its radially innermost point.

The ridges between adjacent flutes on the surface of the rotating drum all have the same shape and size, when seen in a transverse cross-section. As used herein, the term "substantially symmetrical" is used with reference to the receiving surface of a flute delimited between two adjacent ridges to mean that the profile of said receiving surface of a flute may be not completely symmetrical, yet it is always almost symmetrical with reference to its plane of substantial symmetry.

In transfer drums of an apparatus according to the invention, a ridge separating two adjacent flutes will, in general, not be precisely symmetrical when seen in a transverse cross- section. A part of the ridge to the left of a radial drum plane defining a plane of substantial symmetry for the ridge will differ slightly from the remaining part of the ridge to the right of the radial drum plane. For each ridge, a "plane of substantial symmetry" is also a radial drum plane.

This slight asymmetry of the cross section of the ridges is advantageous in that, as the drum rotates about its axis, it makes it easier for a filter rod segment to be received into a flute and to be released from the flute at the output. The difference between the left and right parts of the ridge will generally depend on whether the drum is designed to rotate in a clockwise direction or in a counter-clockwise direction.

Accordingly, the term "substantially" is used to connote that precise symmetry of the flute receiving surface with respect to a radial plane of the drum is not required.

When a filter rod segment is received in a flute, the receiving surface of the flute contacts a portion of the outer surface of the filter rod. When this is seen in a transverse cross-section, the receiving surface of the flute contacts the outer surface of the filter rod segment over an arc extending between two end points. The expression "at least at two points separated by at least 150 degrees about the periphery of the filter rod segment" is used through the specification to describe an arrangement wherein the arc over which the receiving surface of the flute contacts the outer surface of the filter rod segment extends between two end points that are 150 degrees or more apart from one another about the periphery of the filter rod segment (or along the profile of the receiving surface of the flute).

It is understood that, when seen in a cross-section, the receiving surface of each flute shall contact the outer surface of the filter rod segment over an arc of at most about 180 degrees, otherwise the filter rod segment would effectively be stuck within the flute and it would become impossible for the filter rod segment to be released substantially only by gravity upon reaching the output station.

As used herein, the expression "transverse cross section" is used to describe a view of the profile of the groove or notch forming a flute of a rotating drum from the position of a plane substantially perpendicular to the longitudinal axis of the flute.

The term "curved" is used in the present specification to describe any non-straight line, including circular arc, parabolic arc, hyperbolic arc, elliptical arc. The term "conveyance direction" is used in this specification to describe the direction along which a filter rod segment is advanced at a given location along a filter rod segment path. Where a filter rod segment is advanced along a substantially straight portion of the filter rod segment path, such as the one defined by a linear conveyor, the conveyance direction is also substantially parallel to a longitudinal axis of the linear conveyor, and remains substantially unchanged over a length of the filter rod segment path, for example approximately for the whole length of a linear conveyor.

Where a filter rod segment is advanced along a curved portion of the filter rod segment path, such as the one defined by a rotary conveyor (for example, a rotating drum, or a conveyance disc), the conveyance direction also curves, that is, it varies along the curved portion. This is referred to by the expression "curving conveyance direction". At any given location along the curved portion of the filter rod segment, the curving conveyance direction is substantially parallel to the tangent to the curved portion of the filter rod segment path at said location.

An apparatus according to the present invention comprises a rotating drum having at least one flute on a peripheral surface of the drum. The at least one flute extends longitudinally along an axis (F) parallel to a rotation axis of the drum and is adapted, as the drum rotates, to receive a filter rod segment and to convey the filter rod segment to an output station.

Preferably, the rotating drum comprises a plurality of flutes on the peripheral surface of the drum. More preferably, the flutes are equally spaced apart about the periphery of the drum. Adjacent flutes are separated by a ridge. When seen in a transverse cross-section, the ridges between adjacent flutes on the surface of the rotating drum all have the same shape and size.

Further, the apparatus comprises a transfer assembly for receiving the filter rod segment at the output station and for advancing the filter rod segment from the output station in a first conveyance direction extending substantially parallel to the rotation axis of the drum. In practice, at the output, the flute advancing the filter rod segment becomes aligned with the first conveyance direction, such that the flute is operatively coupled with the transfer assembly for delivering the filter rod segment to the transfer assembly.

In a transverse cross section, a receiving surface of the at least one flute is substantially symmetrical with respect to a radial plane (X) of the drum, such that the receiving surface of the flute contacts the outer surface of the filter rod segment at least at two points separated by at least about 150 degrees about the periphery of the filter rod segment. More preferably, the receiving surface of the flute contacts the outer surface of the filter rod segment at least at two points separated by at least about 160 degrees. Even more preferably, the receiving surface of the flute contacts the outer surface of the filter rod segment at least at two points separated by at least about 165 degrees. Most preferably, the receiving surface of the flute contacts the outer surface of the filter rod segment at least at two points separated by at least about 170 degrees. In addition, the two farthest points about the periphery of the filter rod segment at which the receiving surface of the flute contacts the outer surface of the filter rod are separated by less than about 180 degrees. Preferably, the two farthest points about the periphery of the filter rod segment at which the receiving surface of the flute contacts the outer surface of the filter rod are separated by less than about 175 degrees.

Preferably, the receiving surface of the flute contacts the outer surface of the filter rod segment substantially all over an arc of at least about 150 degrees about the periphery of the filter rod segment. More preferably, the receiving surface of the flute contacts the outer surface of the filter rod segment substantially all over an arc of at least about 160 degrees about the periphery of the filter rod segment. In practice, the ridges between the flutes are shaped and arranged such that the receiving surface of the flute envelops less than about half of the peripheral surface of the filter rod segment, and always at least about 40 percent of the peripheral surface of the filter rod segment. This ensures that the filter rod segment is safely and steadily held within the flute, with the longitudinal axis of the filter rod segment in alignment with the longitudinal axis (F) of the flute.

Preferably, when seen in a transverse cross-section, the receiving surface of the at least one flute extends between a first and a second end points (A, B), with the first and the second end points (A, B) being located on opposite sides of the plane (X) of substantial symmetry of the at least one flute.

Preferably, the first and second end points (A, B) are separated by at least about 150 degrees about the periphery of the filter rod segment. More preferably, the first and second end points (A, B) are separated by at least about 160 degrees about the periphery of the filter rod segment. In addition, the first and second end points (A, B) are separated by less than about 180 degrees about the periphery of the filter rod segment. Preferably, the first and second end points (A, B) are separated by less than about 175 degrees about the periphery of the filter rod segment.

A plane tangent to the flute receiving surface at the first point (A) forms a first non-null angle (a) with the flute plane (X) and a plane tangent to the flute receiving surface at the second point (B) forms a second non-null angle (β) with the flute plane (X). The sum of the first angle (a) and the second angle (β) is preferably less than about 40 degrees. More preferably, the sum of the first angle (a) and the second angle (β) is less than about 35 degrees. In addition, or as an alternative, the sum of the first angle (a) and the second angle (β) is preferably at least about 26 degrees. In some preferred embodiments, the sum of the first angle (a) and the second angle (β) is from about 27 degrees to about 33 degrees.

Preferably, the first angle (a) is less than about 30 degrees. In addition, or as an alternative, the first angle (a) is at least about 20 degrees. In some preferred embodiments, the first angle (a) is from about 24 degrees to about 27 degrees. Preferably, the second angle (β) is less than about 10 degrees. In addition, or as an alternative, the second angle (β) is at least about 3 degrees. In some preferred embodiments, the second angle (β) is from about 4 degrees to about 6 degrees.

It shall be understood that the shape of the ridges separating adjacent flutes on the surface of the drum may be such that, when seen in cross section, the profile of the ridge comprises a first portion substantially matching the circular profile of a filter rod segment and a second portion extending from the first portion and forming, with the radial drum plane (X) of substantial symmetry of the flute, a third non-null angle different from either the first angle (a) or the second angle (β). A second portion of the ridge having such shape may further help release the filter rod segment from the flute when the output station is reached.

In preferred embodiments, the transfer assembly comprises a first linear conveyor extending substantially parallel to an axial direction of the drum, the first linear conveyor being operatively coupled with stationary guide means for maintaining the orientation of the axis of the filter segment in the first conveyance direction; and a conveyance disc located downstream from the first linear conveyor and adapted to engage the filter segment and to transport the filter segment along a curving conveyance direction. Further, the transfer assembly preferably comprises a motorised moving means operatively coupled with the first linear conveyor and the conveyance disc and adapted to adjust the orientation of the axis of the filter segment from the first conveyance direction to the curving conveyance direction.

By engaging the filter rod segment with a motorised moving means, an apparatus according to the present invention is adapted to more effectively and smoothly change the orientation of a filter rod segment as it disengages from the first linear conveyor and engages the conveyance disc. In particular, it is understood that the motorised moving means exerts on the filter rod segment an action such as to delicately forward the advancement of the filter rod segment leaving the first linear conveyor whilst at the same time favouring the prompt engagement of the filter rod segment with the conveyance disc.

At the same time, because the moving means is motorised, it is easy to adjust its speed to control an advancement speed of the filter rod segment. By way of example, the filter rod segment may intentionally be caused to move faster or more slowly for a period of time, such as to favour the correct engagement of the filter rod segment with the conveyance disc.

Thus, the likelihood that the filter rod segment slips against the conveyance disc, which could disrupt the desired alignment, sequential arrangement and mutual spacing between consecutive filter rod segments is advantageously greatly reduced. This is particularly advantageous where the combiner handles shorter filter segments, because the correct positioning, alignment and mutual spacing of the filter segments downstream of the conveyance disc can be more consistently and efficiently controlled. Preferably, the motorised moving means comprises a movable surface and is arranged such that a passageway for receiving the at least one filter segment is defined between the moving surface of the motorised moving means and the conveyance disc, and the moving surface of the guiding disc cooperates with the at least one filter segment as it disengages from the first linear conveyor.

In an embodiment, the motorised moving means comprises a guiding disc rotatable about an axis substantially parallel to, and offset from, a rotation axis of the conveyance disk. A lateral surface of the guiding disc defines the moving surface cooperating with the at least one filter rod segment. By adjusting the offset between the rotation axes of the conveyance disc and of the guiding disc, or by varying the diameter of the guiding disc, it is advantageously easy to adjust the width of the passageway for receiving the filter rod segment. Accordingly, it is easy to adapt the apparatus for handling filter rod segments having different diameters, as well as to adjust the amount of friction exerted on the filter rod segments. This is particularly advantageous when filter rod segments with particular features, such as a thicker or stiffer plug wrap, are handled.

In another embodiment, the motorised moving means comprises a guiding linear conveyor.

Preferably, the guiding linear conveyor comprises an endless belt looped around two or more pulleys. A side of the endless belt defines the moving surface cooperating with the at least one filter rod segment. This is particularly advantageous because a guiding linear conveyor provides for a greater contact surface and so cooperation between the moving surface and the filter rod segment can last longer than in the case of a rotary guiding means. Accordingly, the orientation of the filter rod segment may be controlled with greater precision. Further, when a side of an endless belt defines the moving surface, in view of the inherent flexibility of the belt material and by adjusting the belt tension, it is advantageously possible to control/reduce the friction exerted on the filter rod segment as it engages the conveyance disc.

Preferably, the stationary guide means are adjustable such as to vary a width of a passageway defined by the stationary guide means and the first linear conveyor. This is advantageous in that the apparatus may easily be adapted to handle filter rod segments having different diameters and features, and the amount of friction exerted on a filter rod segment may be reduced whilst ensuring, at the same time, that the orientation of the filter rod segment along the first conveyance direction is correctly maintained.

In some preferred embodiments, the apparatus further comprises a cutting head comprising a plurality of circular knives mounted in a housing of the cutting head operatively coupled with the rotating drum; and a guiding jacket, wherein the jacket has a uniform substantially cylindrical surface for guiding the filter rod segments and a plurality of slots for receiving the circular knives of the cutting head. The present invention further provides a method of handling filter rod segments for use in the manufacture of smoking articles. The method comprises conveying a filter rod segment in at least one elongate holding means. For example the filter rod segment may be conveyed in a flute of a rotating drum substantially along a circular arc defined by the periphery of the rotating drum. Further, the method comprises removing the filter rod segment from the at least one holding means and advancing the filter rod segment along a first conveyance direction substantially parallel to an axial direction of the holding means. Advancing the filter rod segment comprises maintaining the orientation of the axis of the filter segment in the first conveyance direction by means of stationary guide means. In addition, the method comprises transporting the filter rod segment along a curving conveyance direction to bring the orientation of the axis of the filter rod segment from the first conveyance direction to a second conveyance direction; and moving the filter rod segment to adjust the orientation of the axis of the filter rod segment from the first conveyance direction to the curving conveyance direction by engaging the filter rod segment with a moving surface of a motorised moving means.

Preferably, the step of maintaining the orientation of the axis of the filter rod segment in the first conveyance direction comprises adjusting a position of the stationary guide means to vary a width of a passageway for receiving the at least one filter segment.

The advantages of the aspects of the method have already been discussed in combination with the aspects of the apparatus and will therefore not be repeated here. Preferably, the apparatus and method according to the present invention and as described above are used in the manufacture of smoking articles, especially of filter cigarettes.

The invention will be further described, by way of example only, with reference to the drawings of the accompanying Figures, wherein:

Figure 1 illustrates a schematic perspective view of a rotating drum of an apparatus according to the present invention;

Figure 2 illustrates a schematic cross-sectional view of a flute of the rotating drum of Figure 1 ;

Figure 3 illustrates a schematic bottom view of a first embodiment of a transfer assembly of an apparatus according to the present invention; and

Figure 4 illustrates a schematic bottom view of a second embodiment of a transfer assembly of an apparatus according to the present invention.

Figure 1 depicts a rotating drum 100 of an apparatus for handling filter rod segments for use in the manufacture of smoking articles in accordance with the present invention. The rotating drum 100 comprises a plurality of flutes 102 on a peripheral surface of the drum. Each flute extends longitudinally along an axis F parallel to a rotation axis O of the drum 100. Further, each flute 102 is adapted, as the drum rotates, to receive a filter rod segment and to convey the filter rod segment to an output station.

The flutes 102 are equally spaced apart about the periphery of the drum 100. Adjacent flutes 102 are separated by a ridge 104. When seen in a transverse cross-section (see Figure 2), the ridges 104 between adjacent flutes 102 on the surface of the rotating drum all have the same shape and size. As shown in Figure 2, a receiving surface 106 of each flute 102 is substantially symmetrical with respect to a radial plane X of the drum, such that the receiving surface 106 of the flute 102 contacts the outer surface of a filter rod segment 108 at least at two points separated by more than 160 degrees about the periphery of the filter rod segment 108. In particular, in the embodiment of Figure 2, the receiving surface 106 of the flute contacts the outer surface of the filter rod segment 108 at two points A and B separated by about 165 degrees about the periphery of the filter rod segment 108. In practice, when seen in cross section as in the drawing of Figure 2, points A and B on the receiving surface 106 of the flute are connected by a substantially circular arc extending by about 165 degrees. This is illustrated in Figure 2 by the angle Θ subtended by the arc connecting points A and B.

Points A and B are effectively also end points of the receiving surface 106 and are located on opposite sides of the radial plane X. A plane T1 tangent to the flute receiving surface 1 10 at the first point A forms a first angle a with the radial plane X. A plane T2 tangent to the flute receiving surface 1 10 at the second point B forms a second angle β with the radial plane X. The first angle a is about 27 degrees, the second angle β is about 6 degrees, and so their sum is about 33 degrees.

The flute receiving surface 106 envelops the filter rod segment 108, such that it is held within the flute 102 with the longitudinal axis of the filter rod segment 108 in substantial alignment with the axis of the flute 102. This is advantageous when, as the drum rotates about its axis, the flute 102 holding the filter rod segment 108 reaches the output station, where the filter rod segment 108 is delivered to a transfer assembly of the apparatus according to the present invention.

A first embodiment 200 of one such transfer assembly is illustrated in Figure 3. The transfer assembly 200 receives the filter rod segment at the output station and advances the filter rod segment from the output station in a first conveyance direction H extending substantially parallel to the rotation axis of the drum. The transfer assembly 200 comprises a first linear conveyor 202 extending substantially parallel to an axial direction of the drum. The first linear conveyor 202 is operatively coupled with stationary guide means 204 for maintaining the orientation of the axis of the filter segment in the first conveyance direction H. Further, the transfer assembly 200 comprises a conveyance disc 206 located downstream from the first linear conveyor 202 and adapted to engage the filter segment and to transport the filter segment along a curving conveyance direction C.

The transfer assembly 200 further comprises a motorised moving means 208 operatively coupled with the first linear conveyor 202 and the conveyance disc 206 and adapted to adjust the orientation of the axis of the filter segment from the first conveyance direction H to the curving conveyance direction C.

In more detail, the motorised moving means 208 comprises a movable surface and is arranged such that a passageway for receiving the at least one filter segment is defined between the moving surface of the motorised moving means 208 and the conveyance disc 206. The moving surface of the motorised moving means 208 cooperates with the filter segment as it disengages from the first linear conveyor 202. In the embodiment of Figure 3, the motorised moving means 208 is provided as a guiding disc rotatable about an axis substantially parallel to, and offset from, a rotation axis of the conveyance disc 206. A lateral surface of the guiding disc 208 defines the moving surface cooperating with the filter segment as it disengages from the first linear conveyor.

Figure 4 illustrates an alternative embodiment 300 of the transfer assembly. The transfer assembly 300 is described below only insofar as it differs from the transfer assembly 200 of Figure 3, and, wherever possible, the same numerals will be used to identify corresponding components of the two transfer assemblies. In the transfer assembly 300, the motorised moving means 308 is provided as an endless belt looped around two or more pulleys. A side of the endless belt 308 defines the moving surface cooperating with the filter segment as it disengages from the first linear conveyor 202.

Claims

1 . Apparatus for handling filter rod segments for use in the manufacture of smoking articles, the apparatus comprising:

a rotating drum having at least one flute on a peripheral surface of the drum, the at least one flute extending longitudinally along an axis (F) parallel to a rotation axis of the drum and adapted, as the drum rotates, to receive a filter rod segment and to convey the filter rod segment to an output station; and

a transfer assembly for receiving the filter rod segment at the output station and for advancing the filter rod segment from the output station in a first conveyance direction extending substantially parallel to the rotation axis of the drum,

wherein, when seen in a transverse cross section, a receiving surface of the at least one flute is substantially symmetrical with respect to a radial plane (X) of the drum, such that the receiving surface of the flute contacts the outer surface of the filter rod segment at least at two points separated by at least 150 degrees about the periphery of the filter rod segment.

2. Apparatus according to claim 1 , wherein, when seen in a transverse cross-section, the receiving surface of the at least one flute extends between a first and a second end points (A, B), the first and the second end points being located on opposite sides of the plane (X) of substantial symmetry of the at least one flute; wherein a plane tangent to the flute receiving surface at the first point (A) forms a first non-null angle (a) with the flute plane (X) and a plane tangent to the flute receiving surface at the second point (B) forms a second non-null angle (β) with the flute plane (X); and wherein the sum of the first angle (a) and the second angle (β) is less than about 40 degrees.

3. Apparatus according to claim 2, wherein the first angle (a) is less than about 30 degrees.

4. Apparatus according to claim 2 or 3, wherein the second angle (β) is less than about 10 degrees.

5. Apparatus according to any one of the preceding claims, wherein the transfer assembly comprises: a first linear conveyor extending substantially parallel to an axial direction of the drum, the first linear conveyor being operatively coupled with stationary guide means for maintaining the orientation of the axis of the filter segment in the first conveyance direction; and a conveyance disc located downstream from the first linear conveyor and adapted to engage the filter segment and to transport the at least one filter segment along a curving conveyance direction; wherein the transfer assembly comprises a motorised moving means operatively coupled with the first linear conveyor and the conveyance disc and adapted to adjust the orientation of the axis of the filter segment from the first conveyance direction to the curving conveyance direction.

6. Apparatus according to claim 5, wherein the motorised moving means comprises a movable surface and is arranged such that a passageway for receiving the filter segment is defined between the moving surface of the motorised moving means and the conveyance disc, and the moving surface of the motorised moving means cooperates with the filter segment as it disengages from the first linear conveyor.

7. Apparatus according to claim 6, wherein the motorised moving means comprises a guiding disc rotatable about an axis substantially parallel to, and offset from, a rotation axis of the conveyance disc, a lateral surface of the guiding disc defining the moving surface.

8. Apparatus according to claim 6, wherein the motorised moving means comprises a guiding linear conveyor.

9. Apparatus according to claim 8, wherein the guiding linear conveyor comprises an endless belt looped around two or more pulleys, a side of the endless belt defining the moving surface.

10. Apparatus according to any one of the preceding claims, wherein the stationary guide means are adjustable such as to vary a width of a passageway defined by the stationary guide means and the first linear conveyor.

1 1 . Apparatus according to any one of the preceding claims further comprising: a cutting head comprising a plurality of circular knives mounted in a housing of the cutting head operatively coupled with the rotating drum; and a guiding jacket, wherein the jacket has a uniform substantially cylindrical surface for guiding the filter rod segments and a plurality of slots for receiving the circular knives of the cutting head.

12. A method of handling filter rod segments for use in the manufacture of smoking articles, comprising:

conveying a filter rod segment in at least one elongate holding means;

removing the filter rod segment from the at least one holding means and advancing the filter rod segment along a first conveyance direction substantially parallel to an axial direction of the holding means; wherein advancing the filter rod segment comprises maintaining the orientation of the axis of the filter segment in the first conveyance direction by means of stationary guide means; transporting the filter rod segment along a curving conveyance direction to bring the orientation of the axis of the filter rod segment from the first conveyance direction to a second conveyance direction; and

moving the filter rod segment to adjust the orientation of the axis of the filter rod segment from the first conveyance direction to the curving conveyance direction by engaging the filter rod segment with a moving surface of a motorised moving means.

13. A method according to claim 12, wherein the step of maintaining the orientation of the axis of the filter rod segment in the first conveyance direction comprises adjusting a position of the stationary guide means to vary a width of a passageway for receiving the at least one filter segment.