A drum for a tobacco industry product assembly machine

Abstract

The present disclosure relates to a drum for conveying rods through a tobacco industry product assembly machine. The drum (113) comprises a plurality of pairs of carriages (402) arranged about a peripheral surface of a drum body (401). Each carriage (402) comprises a flute (404) adapted to carry a rod, wherein the flute (404) of each carriage (402) comprises a first end and a second end opposite the first end. The drum (113) is configured so that, during rotation of the drum body (401), the carriages (402) in each pair of carriages move from a first configuration in which the first ends of the flutes (404) face each other and the second ends of the flutes (404) face away from each other, to a second configuration in which the second ends of the flutes (404) face each other and the first ends of the flutes (404) face away from each other. The present disclosure also relates to an apparatus (100) for assembling tobacco industry products and to a method of manufacturing a drum (113) for conveying rods through a tobacco industry product assembly machine.

Description

[0001] A DRUM FOR A TOBACCO INDUSTRY PRODUCT ASSEMBLY MACHINE

[0002] Technical Field

[0003] The present invention relates to a drum for conveying rods through a tobacco industry product assembly machine.

[0004] Background

[0005] Apparatus for making rod shaped consumables of the tobacco industry typically comprise several drums arranged to convey rod shaped components in a direction transverse to their length (i.e. sideways). The drums generally include a plurality of flutes (i.e. grooves) formed on their peripheral surfaces. The flutes are provided with suction holes configured to retain the components or tobacco industry products in the flutes for the desired portion of the rotation of the drum over which an assembly operation may be performed. Components or tobacco industry products are transferred from one drum to another at the point where the drums are closest to each other.

[0006] Summary

[0007] In a first aspect of the present invention, there is provided a drum for conveying rods through a tobacco industry product assembly machine, the drum comprising a plurality of pairs of carriages arranged about a peripheral surface of a drum body, each carriage comprising a flute adapted to carry a rod, wherein the flute of each carriage comprises a first end and a second end opposite the first end, and wherein the drum is configured so that, during rotation of the drum body, the carriages in each pair of carriages move from a first configuration in which the first ends of the flutes face each other and the second ends of the flutes face ends of the drum body, to a second configuration in which the second ends of the flutes face each other and the first ends of the flutes face ends of the drum body.

[0008] The drum may be configured so that, during rotation of the drum body, the carriages in each pair of carriages move from the first configuration to the second configuration and back to the first configuration in one complete rotation of the drum body.

[0009] The carriages in each pair of carriages may rotate from the first configuration to the second configuration about an axis that extends radially from a rotational axis of the drum body. The drum may be configured so that, in each pair of carriages, one carriage rotates in a first rotational direction and the other rotates in a second rotational direction, opposite to the first rotational direction, to move from the first configuration to the second configuration.

[0010] The drum may be configured so that each carriage in each pair of carriages rotates back into the second configuration in a direction of rotation that is opposite to the direction of rotation of the carriages during their rotation from the first configuration to the second configuration.

[0011] Rotation of each carriage in each pair of carriages may occur at the same time.

[0012] The drum may be configured so that an area swept by one carriage in each pair of carriages during rotation of the carriage does not overlap an area swept by the other carriage of the same pair of carriages during rotation of said other carriage.

[0013] For each carriage, the axis about which it rotates may be substantially perpendicular to a longitudinal axis of its flute.

[0014] In either the first or second configuration, the longitudinal axes of the flutes may extend parallel to the rotational axis of the drum.

[0015] In either the first or second configuration, the flutes of the carriages in each pair of carriages may be in axial alignment.

[0016] Each carriage may rotate through 180 degrees to move from the first configuration to the second configuration and through a further 180 degrees to move back from the second configuration to the first configuration.

[0017] The carriages may be arranged circumferentially about the drum body in two rows, each carriage being aligned with a carriage of the other row in an axial direction of the drum.

[0018] Each carriage may comprise two or more flutes.

[0019] The drum may further comprise a cam and an arrangement of cam followers disposed within the drum body to engage the cam, wherein each carriage is associated with a cam follower, and wherein each cam follower is configured to rotate its respective carriage as the drum body rotates.

[0020] Each cam follower maybe displaced in an axial direction of the drum when the drum rotates.

[0021] The drum body may be configured to rotate independently of the cam. Each carriage may rotate on a spindle that extends radially into the drum body, the spindle comprising a pinion gear that engages a rack of the cam follower so that, on rotation of the drum body, the spindles and carriages are rotated by displacement of the cam followers.

[0022] The carriages of each pair of carriages may comprise first and second carriages, the first carriage being associated with a first cam follower and the second carriage being associated with a second cam follower and wherein the cam comprises a first cam profile at a first end of the drum body and a second cam profile at a second end of the drum body, the first cam follower engaging the first cam profile and the second cam follower engaging the second cam profile.

[0023] The first cam profile may mirror the second cam profile.

[0024] The first and second cam profiles may comprise the following four regions: a first region having a flat profile so as not to change the position of the cam followers passing thereover; a second region having a rising profile so as to advance the cam followers passing thereover away from a respective end of the drum body; a third region having a flat profile so as not to change the position of the cam followers passing thereover; and a fourth region having a falling profile so as to return the cam followers passing thereover toward their respective end of the drum body.

[0025] Optionally: the first region maintains the carriages in the first configuration for receiving rods; the second region rotates the pairs of carriages from the first configuration to the second configuration; the third region maintains the carriages in the second configuration for offloading the rods; and the fourth region rotates the carriages back into the first configuration. The cam profile may track a circle and wherein an arc length of the second region is greater than an arc length of the fourth region.

[0026] The fourth region may be stepped and comprise sequentially arranged regions of falling profile and regions of flat profile.

[0027] Each cam follower may comprise a spring configured to bias the cam follower against the cam.

[0028] Each flute may comprise a suction hole for retaining a rod within the flute.

[0029] The drum may further comprises a manifold within the drum body configured to connect and disconnect the suction hole to a vacuum conduit as the drum body rotates.

[0030] The manifold may be configured to connect the suction holes as their respective carriages move from the first configuration to the second configuration.

[0031] The manifold may be configured to disconnect the suction holes as their respective carriages move from the second configuration back to the first configuration.

[0032] In some embodiments, the carriages are manufactured by 3D printing. It has been found that this advantageously improves ease of manufacturing of the carriages and improves the accuracy with which the suction holes can be positioned, for example, within the flutes of the carriages. In addition, it has been found that 3D printing of the carriages allows for the suction holes to be formed within the carriages without sharp edges / corners / turns of the suction holes passing within the carriages which may otherwise increase turbulence and / or pressure drop on flowthrough the suction holes and allows for larger suction holes.

[0033] In a second aspect of the present invention, there is provided an apparatus for assembling tobacco industry products, comprising the drum of the first aspect.

[0034] According to the present invention, there is also provided a method of manufacturing a drum for conveying rods through a tobacco industry product assembly machine, the method comprising: providing a drum body and a plurality of carriages, each carriage comprising a flute adapted to carry a rod, wherein the flute of each carriage comprises a first end and a second end opposite the first end; and, wherein the method further comprises arranging the carriages in pairs about a peripheral surface of the drum body so that the drum is configured such that, in use, during rotation of the drum body, carriages in a pair of carriages move from a first configuration in which the first ends of the flutes face each other and the second ends of the flutes face away from each other, to a second configuration in which the second ends of the flutes face each other and the first ends of the flutes face away from each other. In some embodiments, providing the plurality of carriages comprises manufacturing the plurality of carriages and, preferably, comprises 3D printing the carriages.

[0035] In some embodiments, the drum manufactured by the method has any of the features of the drum described herein.

[0036] Brief Description of the Drawings

[0037] Fig. 1 shows an apparatus according embodiments of the invention;

[0038] Fig. 2 shows an example consumable made using the apparatus of Fig. 1;

[0039] Fig. 3 is a schematic showing assembly steps carried out on rod shaped components conveyed through the apparatus of Fig. 1;

[0040] Fig. 4 shows a rotation drum according to embodiments of the invention;

[0041] Fig. 5 is a top down view of the rotation drum of Fig. 4 with a schematic overlay of rod shaped components as they enter and leave the drum;

[0042] Fig. 6A is an end on view of the drum of Fig. 4 showing a section line B-B;

[0043] Fig. 6B is a cross section taken through the drum of Fig. 1 along section line B-B;

[0044] Fig. 7 shows a rack of the drum of Fig. 4;

[0045] Fig 8A schematically shows portions of rotation of the drum;

[0046] Fig. 8B schematically shows a cam profile corresponding to the portions of rotations of the drum shown by Fig. 8A;

[0047] Fig. 9 is a cross section taken through the drum of Fig. 4 along section A-A shown in Fig. 5; and

[0048] Fig. 10 shows a partial assembly of the drum of Fig. 4.

[0049] Detailed Description

[0050] As the skilled person will appreciate, apparatus for making rod shaped consumables of the tobacco industry typically comprise several drums arranged to convey rod shaped components in a direction transverse to their length (i.e. sideways). The drums include a plurality of flutes (i.e. grooves) formed on their peripheral surfaces. The flutes of adjacent drums are equally spaced about a pitch circle so that the rod-shaped components can be transferred from one drum to the other at the point where the drums are closest to each other. The flutes are provided with suction holes configured to retain the components in the flutes for the desired portion of the rotation of the drum over which an assembly operation may be performed. Typical apparatus - such as that used to manufacture cigarettes - include drums for cutting, separating and combining rod shaped components. A detailed description of drums for performing these actions is omitted for falling within the purview of the skilled person.

[0051] Fig. i schematically illustrates an apparatus too according to an embodiment of the invention. The apparatus too is configured to make a rod-shaped consumable 200. A crosssection of the rod-shaped consumable 200 is illustrated schematically by Fig. 2. A schematic diagram of the process 300 carried out by the apparatus too of Fig. 1 is illustrated by Fig. 3.

[0052] The rod-shaped consumable 200 comprises a central rod-shaped component 201 connected at either end to first and second additional components 202, 203. The components 201, 202, 203 are circumscribed by first and second wrappers 204, 205 to hold them together. It will be appreciated that the nature of the components may vary but, by way of example, may comprise an aerosol generating section, a plug and a mouthpiece. The aerosol generating section may be the central component 201 and the plug and mouthpiece the components 202, 203 at either end. The aerosol generating section may be configured to release an aerosol when heated by a heating device in the usual way.

[0053] Referring again to Fig. 1, the apparatus too comprises three separate supplies 101, 102, 103 that are configured to feed rod-shaped components to respective transfer drums. The supplies may be, for example, hoppers of the respective rod-shaped components. A first transfer drum 104 receives double length central components 301 and transfers them to a first cutting drum 107 to divide the double length central components 301 into pairs 302 of central components 201. The cutting operation carried out by the first cutting drum 107 on the double length central components 301 is shown schematically at Si of Fig. 3. The pairs 302 of central components 201 are transferred to a separator drum 108 whereupon they are moved axially apart as shown at S2 of Fig. 3 to form axially spaced pairs 303 of central components 201. From the separator drum 108 the axially spaced pairs 303 of central components 201 are transferred to a first combining drum 109. A second transfer drum 105 receives double length first additional components 304 from the second supply 102 and transfers the double length first additional components 304 to the first combining drum 109 such that the double length first additional components 304 are positioned in between the axially spaced central components 201 to form first assemblies 305 as shown at S3 of Fig. 3. The first assemblies 305 are then transferred to a second combining drum 110 for wrapping. The wrapper 204 is introduced at the second combining drum 110 and the first assemblies 305 are rolled against a roll hand 111 to be circumscribed by the wrapper 204 to form first wrapped assemblies 306. The stages of this wrapping process carried out on the second combining drum 110 are shown schematically at S4 and S5 of Fig. 3. Each first wrapped assembly 306 comprises the double length first additional component 304 connected at either end to a central component 201. The first wrapped assemblies 306 are transferred to a second cutting drum 112 whereupon they are divided in half into two sub-assemblies 307. Each sub-assembly 307 comprises a first additional component 202 (half a double length first additional component 304) connected to a central component 201 by a wrapper 204. This cutting step is shown schematically at S6 of Fig. 3. From the second cutting drum 112, the sub-assemblies 307 are transferred in axially aligned pairs to a rotation drum 113. An example rotation drum 113 in accordance with embodiments of the invention is shown in Fig. 4. The rotation drum 113 is configured to rearrange each axially aligned pair of subassemblies 307 - said axially aligned pairs of sub-assemblies 307 being herein referred to as a first position 308 of the sub-assemblies 307 - to a second position 309 of the subassemblies 307 in which the sub-assemblies 307 are again axially aligned, but with their ends swapped around. To achieve this, each sub-assembly 307 in the pair of sub-assemblies is rotated through 180 degrees about an axis perpendicular to its axis. Ends of each subassembly 307 which are adjacent to and facing the other sub-assembly 307 in the pair of subassemblies 307 in the first position 308 become ends of the sub assembly 307 that face outward, away from the adjacent sub-assembly 307, in the second position 309. Put another way, in the first position 308, the ends of the sub-assemblies 307 comprising the first additional components 202 are adjacent and facing and, in the second position, the ends of the sub-assemblies 307 comprising the central component 201 are adjacent and facing. In the illustrated embodiments, the rotation drum 113 also causes a separation of the subassemblies 307 so that in the second position 309 the adjacent ends are further apart than they are in the first position 308, as shown in S7 of Fig. 3. This is achieved by rotating each sub-assembly 307 about an axis offset from their centre as will be explained further below. However, it will be appreciated that it is not essential for the rotation drum 113 to cause separation of the sub-assemblies 307 and that they could instead be rotated about an axis that bisects a centre point of the sub-assemblies 307 so that adjacent ends are equally spaced both in the first and second positions 308, 309. In such examples where separation is not provided by the rotation drum 113, the sub-assemblies may be transferred to a second separator drum (not shown) and separated in the usual way. In the presently described embodiments, the rotated and separated pairs of sub-assemblies 307 are transferred to a third combining drum 114 in spaced axial alignment. A third transfer drum 106 receives double length second additional components 310 and transfers them to the third combining drum 114 such that the double length second additional components 310 are positioned in between the axially spaced sub-assemblies 307 to form second assemblies 311 as shown in S8 of Fig. 3. The second assemblies 311 are then transferred to a fourth combining drum 115 for wrapping. The second wrapper 205 is introduced at the fourth combining drum 115 and the second assemblies 311 are each rolled against a roll hand 116 to be circumscribed by the second wrapper 205 to form second wrapped assemblies 312. The stages of this wrapping process carried out on the fourth combining drum 115 are shown schematically at S9 and S10 of Fig. 3. Each second wrapped assembly 312 comprises the double length second additional component 310 connected at either end to sub-assemblies 307. The second wrapped assemblies 312 are transferred to a third cutting drum 117 whereupon they are divided in half into the rod-shaped consumable of Fig. 2 as illustrated schematically at S11 of Fig. 3.

[0054] The rotation drum 113 is described herein with reference to Figs. 4 to 10. It will be appreciated that, while the rotation drum 113 (hereon after simply drum 113) is described as conveying sub-assemblies 307 in the above described apparatus too, the drum 113 may carry any rod shaped assembly. Beneficially, the drum 113 enables the rotation of pairs of cut rods from a first position in which the rods are axially aligned with a first end of the rods closely spaced or abutting to a second position in which the rods are again axially aligned, but with their ends swapped around so that said first ends of the rod now face away from the other rod. Therefore, the advantages of the drum 113 apply to any apparatus for the manufacture of rod-shaped consumables where a rod shaped component or assembly needs to be rearranged from the first position to the second position in one operation.

[0055] Referring to Fig. 4, the drum 113 comprises a drum body 401 and a plurality of carriages 402 arranged about a peripheral surface 403 of the drum body 401. Each carriage 402 comprises a flute 404 adapted to carry a rod, such as, for example, the sub-assembly 307. The flutes 404 are elongate grooved receptacles in which the rods sit when being conveyed by the drum 113. The drum 113 is configured so that, over a portion of rotation of the drum body 401, the flutes 404 are rotated through 180 degrees about an axis substantially perpendicular to the flute’s longitudinal direction. A rod received in a flute 404 over this portion of rotation of the drum body 401 is therefore rotated from the first position to the second position by the rotation of the carriages 402.

[0056] The carriages 402 are arranged circumferentially about the drum body 403 in two rows 4021, 4022, as shown in Fig. 5. Each carriage 402 is aligned with a carriage of the other row in the axial direction of the drum 113 to form pairs of carriages 402’, 402”. Each pair of carriages 402’, 402” includes a first carriage 402’ and a second carriage 402”. Each first carriage 402’ is adjacent a first end 405 of the drum 113 and each second carriage 402” adjacent a second end 406 of the drum 113.

[0057] Rotation of the drum body 401 is divided into four portions. Each portion of rotation refers to the angular range that a pair of carriages 402’, 402” traverse about the drums 113 axis X-X for a given phase of movement of the carriages 402’, 402”. In a first portion of rotation the carriages 402, 402” are in a first configuration Di and remain stationary to collect pairs of rods from an adjacent drum. In the first configuration Di, the carriages are positioned to collect the pairs of rods in their first position Pi. The rods in their first position Pi are shown schematically in Fig. 5 adjacent the side of the drum on which the carriages 402’, 402” are in the first configuration Di. The carriages remain in the first configuration Di for the first portion of rotation of the drum body 401. During a second portion of rotation of the drum body 401 the carriages 402’, 402” rotate into a second configuration D2to translate the rods carried thereon from the first position Pi to the second position P2. The rods in their second position P2are shown schematically adjacent the side of the drum on which the carriages 402’, 402” are in the second configuration D2.During a third portion of rotation of the drum body 401 the carriages 402’, 402” are again stationary, remaining in the second configuration D2to allow the rods carried thereon to be transferred to another drum for further processing. During a fourth portion of rotation of the drum body 401, the carriages rotate from the second configuration D2back into the first configuration Di.

[0058] In the exemplary embodiment, the first portion of the drum body 401 is about 30 degrees; the second portion about 160 degrees; the third portion about 30 degrees; and the fourth portion about 140 degrees. Preferably the angular range of the second portion is greater than the angular of the fourth portion. This allows the carriages 402’, 402” more time to move from the first configuration Di to the second configuration D2during the second portion of rotation of the drum body 401 than in the fourth portion of rotation of the drum body 401 which, in turn, means that the acceleration of the carriages 402’, 402” as they move from the first configuration Di to the second configuration D2over the second portion of rotation of the drum body 401 is less than the acceleration of the carriages 402’, 402” as they move back from the second configuration D2into the first configuration Di over the fourth portion of rotation of the drum body 401. Less acceleration of the carriages 402’, 402” over the second portion of rotation is desired so as to reduce the risk of damage to the rods being conveyed thereon. It will be appreciated that maximising the angular range over that the carriages 402’, 402” traverse through the second portion of rotation minimises the acceleration necessitated to move the carriages 402’, 402” from the first configuration Di to the second configuration D2. As the angular range required for picking rods up and transferring them on (i.e. the angular range of the first and third portions of rotation of the drum body 401) is relatively fixed, maximising the angular range for the second portion of rotation is best achieved by minimising the fourth portion of rotation.

[0059] With the carriages in the first or second configurations Di, D2, the flutes 404 are arranged in a pitch circle around the drum’s axis X-X. This means that the rods carried by the flutes 404 traverse a circular path as the drum body 401 rotates and means that the rods are correctly positioned for being collected from and transferred to adjacent drums during the first and third portions of rotation of the drum body 401, respectively.

[0060] Each carriage 402 comprises an arm 407 connected to a spindle 408 on which it rotates. The spindle 408 extends radially into the drum body 401 for connection to a rotation mechanism for rotating the arm 407. The arm 407 is connected to the spindle 408 at a proximal end 407’ and extends perpendicular to the spindle axis. A first flute 404’ is provided at a distal end 407” of the arm 407 and a second flute 404” at a mid-position of the arm 407. So that the flutes 404’, 404” maintain their pitch circle arrangement, the second flute 404” protrudes from the arm’s mid position, being provided in an upper face of a wall 409 that upstands perpendicular from the arm 407, parallel to the spindle axis.

[0061] Fig. 6 is a section taken longitudinally through the drum 113 and illustrates an example rotation mechanism 601. The rotation mechanism 601 comprises a rack 602 that is mechanically connected to a pinion gear 603 so that linear movement of the rack 602 causes rotation of the pinion gear 603. The pinion gear 603 is provided on the spindle 408 and connected thereto so that rotation of the pinion gear 603 causes rotation of the spindle 408. Therefore, linear movement of the rack 602 causes rotation of the spindle 408 and the arm 407 connected thereto. The rotation mechanism 601 is configured to rotate the arm 407 180 degrees on the spindle 408 during the third portion of rotation of the drum body 401. This rotation of the arm 407 corresponds with movement of the carriage 402 between the first and second configurations D2, D2.

[0062] In the illustrated example, the drum 113 comprises 10 pairs of carriages 402’, 402”, meaning that there are also 10 pairs of rotation mechanism 601, one associated with each pair of carriages 402’, 402”. The rack 602 of each rotation mechanism 601 is disposed in a guide 604 internal to the drum body 401. The rack 602 slides within the guide 604 to effect rotation of its respective spindle 408 and carriage 402 and is driven by a cam 6o5which the rack 602 follows as the drum body 401 rotates.

[0063] The cam 605 comprises first and second cams 605’, 605”, one at either end of the drum body 401. The first cam 605’ is disposed at the first end 405 of the drum 113 and the second cam 605” is disposed at the second end 406 of the drum 113. Each cam 605’, 605” remains in a fixed position relative to the drum body 401 throughout operation of the drum 113. Each pair of rotation mechanisms 601 comprises a first rotation mechanism and a second rotation mechanism. The first and second rotation mechanisms 601 are associated with respective first and second carriages 402’, 402”. The rack 602 of the first rotation mechanism is driven by the first cam 605’ and the rack of the second rotation mechanism by the second cam 605”. Therefore, rotation of each first carriage 402’ is effected by a respective first rotation mechanism 6oi driven by the first cam 605’ and rotation of each second carriage 402” is effected by a respective second rotation mechanism 601 driven by the second cam 605”.

[0064] Fig. 7 illustrates in more detail an example rack 602 of the rotation mechanisms 601. The racks 602 comprise a linear gear 701 that engages a respective pinion gear 603, a shaft 702 that locates the rack 602 in a respective guide 604 of the drum body 401, a cam follower 703 and a spring 704. The linear gear 701 is formed in a mid-section the shaft 702 which is supported either side the mid-section by the guide 604. The shaft 702 comprises a forked end 705 in which is located a wheel 706 of the cam follower 703. The spring 704 is a coil spring located coaxially about the shaft 702. One end of the spring 704 is biased against a shoulder 707 of the shaft 702 and the other against a shoulder of the guide 604. The spring 704 works in compression and maintains a force that keeps the cam follower 703 up against the cam 605.

[0065] Each cam 605’, 6o5”comprises a circular track that forms a cam profile. The cam profile of the first cam 605’ is herein a first cam profile and the cam profile of the second cam 605” a second cam profile. As the drum body 401 rotates, the cam followers 703 of the first rotation mechanisms 601 follow the first cam profile 605’ and the cam followers 703 of the second rotation mechanisms 601 follow the second cam profile 605”. The first cam profile mirrors the second cam profile. Therefore, in any given pair of rotation mechanisms, displacement of the rack 602 of the first rotation mechanism 601 by the first cam profile is equal and opposite to the displacement of the rack 602 of the second rotation mechanism by the second cam profile as the drum body 401 rotates. This means that, in any given pair of carriages 402’, 402”, clockwise rotation of the first carriage 402’ occurs concurrently with an anticlockwise rotation of the same magnitude of the second carriage 402” and vice versa.

[0066] Fig. 8A and 8B schematically illustrates the portions of rotation of the drum body 401 with respect to the changing cam profile 801 of the first and second cams 605’, 605”. Each cam profile 801 comprises four regions Ri, R2, R3, R4 (illustrated by Fig. 8B) that correspond with the four portions Pn, Pr2, Pr3, Pr4 of rotation of the drum body 401 (illustrated by Fig. 8A). Each region Ri, R2, R3, R4 of the cam profile covers the same angular range and position as the respective portion Pri, Pr2, Pr3, Pr4 of rotation of the drum body 401. The first region Ri comprises a flat profile 802. The flat profile 802 does not displace the racks 602 as the drum body 401 rotates as it has no gradient in the axial direction of the drum. The second region R2 comprises a rising profile 803. The rising profile 803 comprises a positive gradient in the axial direction and so displaces the racks 602 inwards as the drum body 401 rotates. By ‘inward’ it is meant toward a centre of the drum body 401. When viewed with the first end 405 of the drum 113 on the left and the second end 406 on the right (as in Fig. 5), the first carriages 402’ are rotated anticlockwise by the second region R2 of the first cam profile and the second carriages 402” are rotated clockwise by the second region R2 of the second cam profile. As per the first region Ri, the third region R3 also comprises a flat profile 802 and so does not displace the racks 602. The fourth region comprises a falling profile 804. The falling profile 804 comprises a negative gradient in the axial direction and so enables the racks 602 to move back to their respective end of the drum 113 under spring 704 load as the drum body 401 rotates. When viewed with the first end 405 of the drum 113 on the left and the second end 406 on the right as per Fig. 5, the first carriages 402’ are rotated clockwise by the fourth region R4 of the first cam profile and the second carriages 402” are rotated anticlockwise by the fourth region R4 of the second cam profile.

[0067] As mentioned above, it is desirable to minimize the fourth portion Pr4 of rotation of the drum body 401- that is to say, minimize the angular range of drum body 401 rotation required to return the carriages 402’, 402” from their second configuration D2to their first configuration Di. To achieve this, the fourth region R4 of the cam profile is stepped, comprising sequentially arranged regions of falling profile 804 and flat profile 802. This enables the regions of falling profile 804 to be steeper than if falling profile were linear across the fourth region R4. The carriages 402’, 402” therefore return to their second configuration D2in less rotation of the drum body 401. The angular spacing between the falling profile 804 and the flat profile 802 is such that rotation of one pair of carriages 402 is paused as the next pair begin to rotate. In this way pairs of carriages can complete a large amount of rotation prior to the next pair in the row beginning rotation without carriages 402 of successive rows clashing.

[0068] Fig. 9 shows a cross section taken along the drum’s 113 axis X-X. As illustrated, a drive shaft 901 extends along the drum’s axis between first and second ends of the drum 405, 406. The drive shaft 901 is connected to the drum body 401 so that rotation of the drive shaft 901 causes rotation of the drum body 401. A second end of the drive shaft 902 protrudes at the second end 406 of the drum 113 where it comprises a splined end 903 for connection to a motor or other torque transfer device (not shown). The first end 405 of the drum 113 comprises a first mounting flange 904 and the second end 406 of the drum 113 comprises a second mounting flange 905 to fixedly connect the drum 113 to respective opposing mounting surfaces (not shown). The first and second mounting flanges 904, 905 are held stationary by their respective mounts so that the drive shaft 901 and the drum body 401 rotate relative to the first and second mounting flanges 904, 905 during operation of the drum 113. The first mounting flange 904 comprises a bearing housing 906. The bearing housing 906 extends into the drum body 401 for a compact assembly. A first roller bearing 907 is supported by the bearing housing 906 to rotatably mount a first end 908 of the drive shaft 901. The first cam 605’ is connected to the first mounting flange 904 to hold it in a fixed position relative to the drum body 401. The first cam 605’ is annular and fits around the bearing housing 906, the circular track of the first cam profile being radially aligned with the cam followers 703 of the first rotation mechanisms for contact therewith.

[0069] The drum comprises a suction system to retain the rod-shaped components in the flutes 404 during rotation of the drum body 401 through the first portion of rotation Pri - when the rod-shaped components are collected from an adjacent drum - to the third portion Pr3 - where the rod-shaped components are transferred on to another adjacent drum. The suction system comprises suction holes 410 in each flute 404 (example holes 410 being labelled in Fig. 4) and a manifold 909 (shown in Figs. 9 and 10) within the drum body 401 to connect and disconnect the suction holes 410 to a vacuum conduit 910 as the drum body 401 rotates. The manifold 909 is configured to fluidly connect the suction holes 410 to the vacuum conduit 910 during the first portion Pri of rotation of the drum body 401 and to maintain that connection until a point in the third portion Pr3 of rotation of the drum body 401.

[0070] The vacuum conduit 910 comprises an internal passageway 911 of the second mounting flange 905 and a connector 912 for connection to a vacuum source (not shown). The connector 912 comprises a standard air fitting threadedly connected at an external opening of the internal passageway 911. In operation of the drum 113, the vacuum source is connected to the connector 912 to maintain a negative gauge pressure within the vacuum conduit 911.

[0071] In some embodiments, the carriages 402 are manufactured by 3D printing. It has been found that this advantageously improves ease of manufacturing of the carriages 402. Furthermore, it has been found that 3D printing of the carriages 402 allows for the suction holes 410 to be more accurately positioned, for example, within the flutes 404 of the carriages 402. In addition, it has been found that 3D printing of the carriages 402 allows for the suction holes 410 to be formed within the carriages 402 without sharp edges / corners / turns of the suction holes 410 passing within the carriages 402 which may otherwise increase turbulence and / or pressure drop on flowthrough the suction holes 410.

[0072] Fig. 10 is a detail view of an assembly comprising the manifold 909, drive shaft 901 , second mounting flange 905 and second cam 605”. Other components are omitted to show the manifold 909 in more detail. The manifold 909 comprises a distributor 1001 and a control ring 1002. The distributor 1001 is connected to the mounting flange 905 and is therefore stationary during operation of the drum 113. The distributor 1001 has a tubular form that is received within the drum body 401, coaxial with the drive shaft 901. A portion of the drive shaft 901 extends through the distributor 1001 for connection to the drum body 401 at a drive shaft flange 1003. The distributor 1001 comprises a cut out 913 in its outer surface that forms a cavity within the drum body 401 (as seen in Fig. 9) and an internal passageway 914 that fluidly connects the cut out 913 with vacuum conduit 911 in the mounting flange 905. The internal passageway 914 of the distributor 1001 is herein referred to as the ‘distributor conduit 914’. The control ring 1002 is a tubular sleeve positioned between the distributor 1001 and the drum body 401 to enclose the cut out 913 in an airtight manner. The control ring 1002 comprises first and second circumferentially extending slotted openings 1004’, 1004”. The slotted openings 1004’, 1004” extend through an angular range equal to the angular range traversed by the carriages 402 from where rods are collected to where rods are transferred to another drum. Therefore, the angular range of the slotted openings 1004’, 1004” is equal to the sum of the first portion Pri of drum rotation (at least in part), the second portion Pr2 of drum rotation and the third portion Pr3 of drum rotation (at least in part). The slotted openings 1004’, 1004” are configured to communicate with internal passageways 915 of the spindles 408, herein referred to as spindle conduits 915. The spindle conduits 915 open at a distal end of each spindle 408 - that is to say, at the end of the spindle opposite the end connected to the arm 407 of a carriage 402. Each spindle conduit 915 communicates with a passageway 916 in the arm 407 of their respective carriage 402. The passageway 916 in the arm 407 is herein referred to as the ‘carriage conduit 916’. Each carriage conduit 916 branches out into four sub conduits which open at the four suction holes 410. It will be appreciated that, while four suction holes 410 per carriage 402 are illustrated (two per flute), more or fewer suctions holes 410 may be used as desired.

[0073] The distal end of each spindle 408 extends into contact with the control ring 1002. Spindles 408 associated with a first carriage 402’ are aligned with the first slotted opening 1004’ and spindles 408 associated with a second carriage 402” are aligned with the second slotted opening 1004”. Therefore, as the drum body 401 rotates, the suction holes 410 of the first carriages 402’ are fluidly connected to the vacuum conduit 911 as their respective spindles 408 pass over the first slotted 1004’ opening and the suction holes 410 of the second carriages 402’ are fluidly connected to the vacuum conduit 911 as their respective spindles 408 pass over the second slotted opening 1004”.

[0074] In the illustrated example, the distributor 1001 comprises a second bearing housing 917. The second bearing housing 917 is an internal recess within the distributor 1001 and is illustrated in the section of Fig. 9. A second roller bearing 918 is supported by the second bearing housing 917 to rotatably mount the drive shaft 901 adjacent its second end 902. In an unillustrated example, a second bearing housing (not illustrated) may instead be provided on the first mounting bracket. It will be appreciated that what is important is that the second bearing housing is located on a stationaiy component adjacent the second end 902 of the drive shaft 901. In the illustrated examples, the rotation drum 113 also causes separation of the rods conveyed by the carriages. As illustrated by Fig. 5, rod shaped 500 components are provided in the first position in which first ends 501 of the rods 500 are abutting.. Following rotation into the second position, second ends of the rods are spaced apart. The rods 500 in the first and second positions Pi, P2 are shown schematically adjacent carriages 402 in the first configuration Di and second configuration D2, respectively. This is achieved by rotating each rod 500 about an axis Rx’, Rx” offset from their centre. The axes Rx’, Rx” are illustrated for each of the first and second rows of carriages 402’, 402”. The rotation axes Rx’, Rx” bisect the rods 500 closer their first ends 501 in their first position Pi so that following rotation about the rotation axes Rx’, Rx”, second ends 502 of the rods 500 are spaced apart.

Claims

Claims1. A drum for conveying rods through a tobacco industry product assembly machine, the drum comprising a plurality of pairs of carriages arranged about a peripheral surface of a drum body, each carriage comprising a flute adapted to carry a rod, wherein the flute of each carriage comprises a first end and a second end opposite the first end, and wherein the drum is configured so that, during rotation of the drum body, the carriages in each pair of carriages move from a first configuration in which the first ends of the flutes face each other and the second ends of the flutes face away from each other, to a second configuration in which the second ends of the flutes face each other and the first ends of the flutes face away from each other.

2. The drum of claim 1, wherein the drum is configured so that, during rotation of the drum body, the carriages in each pair of carriages move from the first configuration to the second configuration and back to the first configuration in one complete rotation of the drum body.

3. The drum of claim 1 or claim 2, wherein the carriages in each pair of carriages rotate from the first configuration to the second configuration about a carriage axis that extends radially from a rotational axis of the drum body.

4. The drum of claim 3, the drum being configured so that, in each pair of carriages, one carriage rotates in a first rotational direction and the other rotates in a second rotational direction, opposite to the first rotational direction, to move from the first configuration to the second configuration.

5. The drum of claim 4, the drum being configured so that, each carriage in each pair of carriages rotates back into the second configuration in a direction of rotation that is opposite to the direction of rotation of the carriages during their rotation from the first configuration to the second configuration.

6. The drum of any of claims 3 to 5, wherein rotation of each carriage in each pair of carriages occurs at the same time.

7. The drum of any of claims 3 to 6, wherein an area swept by one carriage in each pair of carriages during rotation of the carriage does not overlap an area swept by the other carriage of the same pair of carriages during rotation of said other carriage.

8. The drum of any of claims 3 to 7, wherein for each carriage, the axis about which it rotates is substantially perpendicular to a longitudinal axis of its flute.

9. The drum of claim 8, wherein in either the first or second configuration, the longitudinal axes of the flutes extend parallel to the rotational axis of the drum.

10. The drum of any preceding claim, wherein in either the first or second configuration, the flutes of the carriages in each pair of carriages are in axial alignment.

11. The drum of any of claims 3 to 10, wherein each carriage rotates through 180 degrees about the carriage axis to move from the first configuration to the second configuration and through a further 180 degrees to move back from the second configuration to the first configuration.

12. The drum of any preceding claim, wherein the carriages are arranged circumferentially about the drum body in two rows, each carriage being aligned with a carriage of the other row in an axial direction of the drum.

13. The drum of any preceding claim, wherein each carriage comprises two or more flutes.

14. The drum of any preceding claim, further comprising a cam and an arrangement of cam followers disposed within the drum body to engage the cam, wherein each carriage is associated with a cam follower, and wherein each cam follower is configured to rotate its respective carriage as the drum body rotates.

15. The drum of claim 14, wherein each cam follower is displaced in an axial direction of the drum when the drum rotates.

16. The drum of claim 14 or claim 15, wherein the drum body is configured to rotate independently of the cam.

17. The drum of any of claims 14 to 16, wherein each carriage rotates on a spindle that extends radially into the drum body, the spindle comprising a pinion gear that engages a rack of the cam follower so that, on rotation of the drum body, the spindles and carriages are rotated by displacement of the cam followers.

18. The drum of any of claims 14 to 17, wherein the carriages of each pair of carriages comprise first and second carriages, the first carriage being associated with a first cam follower and the second carriage being associated with a second cam follower and wherein the cam comprises a first cam profile at a first end of the drum body and a second camprofile at a second end of the drum body, the first cam follower engaging the first cam profile and the second cam follower engaging the second cam profile.

19. The drum of claim 18, wherein the first cam profile mirrors the second cam profile.

20. The drum of claim 18 or claim 19, wherein the first and second cam profiles comprise the following four regions: a first region having a flat profile so as not to change the position of the cam followers passing thereover; a second region having a rising profile so as to advance the cam followers passing thereover away from a respective end of the drum body; a third region having a flat profile so as not to change the position of the cam followers passing thereover; and a fourth region having a falling profile so as to return the cam followers passing thereover toward their respective end of the drum body.

21. The drum of claim 20, wherein: the first region maintains the carriages in the first configuration for receiving rods; the second region rotates the pairs of carriages from the first configuration to the second configuration; the third region maintains the carriages in the second configuration for offloading the rods; and the fourth region rotates the carriages back into the first configuration.

22. The drum of claim 21, wherein the cam profile tracks a circle and wherein an arc length of the second region is greater than an arc length of the fourth region.

23. The drum of claim 22, wherein the fourth region is stepped and comprises sequentially arranged regions of falling profile and regions of flat profile.

24. The drum of any of claims 18 to 23, wherein each cam follower comprises a spring configured to bias the cam follower against the cam.

25. The drum of any preceding claim, wherein each flute comprises a suction hole for retaining a rod within the flute.

26. The drum of claim 25, wherein the drum further comprises a manifold within the drum body configured to connect and disconnect the suction holes to a vacuum conduit as the drum body rotates.•2. . The drum of claim 26, wherein the manifold is configured to connect the suctions hole as their respective carriages move from the first configuration to the second configuration.

28. The drum of claim 27, wherein the manifold is configured to disconnect the suction holes as their respective carriages move from the second configuration back to the first configuration.

29. The drum of any one of the preceding claims, wherein the carriages are manufactured by 3D printing.

30. Apparatus for assembling tobacco industry products, comprising the drum of any preceding claim.

31. A method of manufacturing a drum for conveying rods through a tobacco industry product assembly machine, the method comprising: providing a drum body and a plurality of carriages, each carriage comprising a flute adapted to carry a rod, wherein the flute of each carriage comprises a first end and a second end opposite the first end; and, wherein the method further comprises arranging the carriages in pairs about a peripheral surface of the drum body so that the drum is configured such that, in use, during rotation of the drum body, carriages in a pair of carriages move from a first configuration in which the first ends of the flutes face each other and the second ends of the flutes face away from each other, to a second configuration in which the second ends of the flutes face each other and the first ends of the flutes face away from each other.

32. A method according to claim 31, wherein providing the plurality of carriages comprises manufacturing the plurality of carriages and, preferably, comprises 3D printing the carriages.

33. A method according to claim 31 or claim 32, wherein the drum has any of the features of any one of claims 1 to 29.

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