TRIMMING DEVICE FOR A CIGARETTE MAKING MACHINE

Abstract: A trimming device for trimming a cigarette filler stream in a cigarette making machine while it is being carried by a suction band (18) comprises a first continuously moving part (10) which moves adjacent to one side of the filler stream and at substantially the same speed, and a second continuously moving part (12) having an edge which moves obliquely across the filler stream, towards the side thereof which is supported by the first moving part, so as to remove excess tobacco. The two moving parts are preferably both in the form of discs (10 and 12), the first having its axis of rotation lying above and transverse to the band and parallel to the plane of the band, and the second having its axis of rotation below the band, substantially parallel to the plane of the band, but skewed so that its edge lies obliquely across the filler stream.

Description: l Trimming Device for a Cigarette Making Machine 2 3 It is common, in a cigarette making machine, to form a cigarette .. filler stream initially with excess tobacco, and then to remove some of the 5 tobacco by means of a trimming device. An early form of trimming 6 device of a type similar to some which have continued to be used is 7 described in United Kingdom Patent No. 881024. However, it has β become common more recently to trim the filler stream while compacting 9 it by means of suction applied through an air-pervious band carrying the ιo filler stream. ii The invention provides a trimming device for trimming a cigarette i2 filler stream supported by an endless band in a cigarette making i3 machine, said device comprising a first continuously movable part I* arranged for supporting a side region of said filler stream over at least a is portion of the depth of the stream and to be movable at substantially the i6 same speed as the stream, and a second continuously movable part i7 arranged such that an edge thereof can be moved obliquely across said is band towards said side region of the stream supported by the first part i9 so as to remove excess tobacco from said filler stream. 20 The invention also includes a trimming device for trimming a 2i cigarette filler stream in a cigarette making machine while it is being 22 carried by a suction band, comprising a first continuously moving part 23 which moves adjacent to one side of the filler stream and at substantially u the same speed, and a second continuously moving part having an edge 25 which moves obliquely across the filler stream, towards the side thereof 26 which is supported by the first moving part, so as to remove excess 27 tobacco. 2 s The invention also includes a twin track cigarette machine 29 comprising two suction bands arranged in parallel spaced apart 30 relationship and, associated with said bands, respective trimming 3i devices according to either of the last two preceding paragraphs. 32 The two movable parts are preferably both in the form of discs. In 33 a preferred embodiment the first disc has its axis of rotation lying above 3 4 and transverse to the band, and parallel to the plane of the band and the 35 second disc has its axis of rotation below the band, substantially parallel 36 to the plane of the band, but skewed so that its edge lies obliquely 3 7 across the filler stream. The peripheries of the discs both preferably 38 have regularly spaced portions of larger and smaller diameters which 1 mesh so as to leave the filler stream with thicker "dense end" portions at 2 regular intervals. The lower disc is preferably larger in diameter than the 3 upper disc, but rotates at the same speed so that its edge where it 4 engages the filler stream has a velocity component, in the direction of 5 movement of the band, which is substantially equal to the velocity of the 6 band. 7 Alternatively, the second disc may lie in a plane parallel to the s band, so that its relationship with the band and the tobacco is similar to 9 that of each of the trimming discs shown in the above-mentioned patent, ιo except that the disc according to this invention would extend all the way ii across the tobacco filler stream. Removal of excess tobacco may be i2 assisted by means of a rotating brush-like member as described in the i3 above-mentioned patent. In contrast in the preferred construction i4 described above, the lower disc displaces the excess tobacco laterally is away from the tobacco remaining on the suction band, so that the i6 excess is able to drop under gravity without any risk of being retained by i7 the suction applied through the band immediately downstream of the is trimming device. i9 Examples of trimming devices according to this invention are 20 shown in the accompanying drawings. In these drawings: 2i Figure 1 is a front view of one device; 2 2 Figure 2 is a section on the line ll-ll in Figure 1 ; 23 Figure 3 is an enlargement of part of Figure 2; and 2 Figures 4 and 5 show alternative arrangements. 25 Figure 1 shows upper and lower discs 10 and 12, and a manifold 26 14 through which suction is applied through a suction band 18 (shown in 27 Figures 2 and 3) in the region of the trimming device, as described 28 below. 29 The lower disc 12 has regularly spaced peripheral portions 12A 30 which are cut away to define recesses so that effectively the disc 3i diameter in those regions is smaller. Where these recesses 12A act on 32 the tobacco, they leave additional "dense ending" quantities of tobacco 33 in positions corresponding to the ends of the final cigarettes. The upper 34 disc 10 has corresponding larger-diameter portions 10A which mesh 35 with the recesses 12A of the disc 12. 36 As shown more particularly in Figure 2, the upper disc 10 is 37 mounted on a shaft 16. This shaft has its axis parallel to the plane of a 38 suction band 18 (shown more clearly in Figure 3) and at right angles to 1 the centre line of the suction band. Thus the right-hand surface of the 2 disc 10 supports the left-hand side of the filler stream during trimming. 3 Trimming results from the fact that the lower disc 12 has its axis 4 skewed so that the edge of the disc lies obliquely across the band 18 at 5 a distance corresponding to the height of the filler stream which is e required to be retained on the band. Thus the edge of the disc 12 7 shears away excess tobacco while the side of the filler stream towards β which the excess tobacco is displaced is supported by the disc 10. 9 Excess tobacco is swept away by the shearing action and then drops ιo under gravity as indicated by the arrow 19 in Figure 2. a As already mentioned, in the region of the trimming device suction i2 is applied through the suction band via the manifold 14; this has a i3 narrow suction inlet 14A and diverges from there so as to transmit i4 suction to a space 20 extending parallel to the band along a distance is slightly greater than the diameters of the discs. Before and after the i6 trimming device, suction is applied through the band from a suction i7 chamber above the band in the usual way. is As shown in Figure 3, the disc 12 is so positioned that its edge at i9 its highest point is adjacent to the edge of the disc 10. As also shown in 20 Figure 3, the band 18 runs along parallel skids 22. Suction is transmitted 2i from the space 20 to the space immediately above the band 18 via a 22 series of spaced slots 24 in a member 26 carrying the skids 22. 23 As mentioned above, the diameter of the lower disc 12 is slightly 2 greater than that of the upper disc. The discs 10,12 are driven at the 25 same speed so that the peripheral velocity of the larger disc 12 is greater 26 than the peripheral velocity of the smaller disc 10. By suitable selection 27 of the disc diameters and the skew angle of the axis of the disc 12, it is 28 possible to arrange for the edge of the disc 12 where it engages the filler 29 stream to have a velocity component in the direction of movement of the 30 band which is equal, or at least substantially equal, to the velocity of the 3i band and therefore to the velocity of the filler stream carried thereon. 32 The arrangement as shown trims a cigarette filler stream 28 at a 33 fixed height, apart from the variations to allow for dense ending. In 34 conventional trimmers to date, the trimming discs have been movable up 35 or down to vary the amount of tobacco removed from the filler stream in 36 order to maintain the desired cigarette density. The same arrangement 37 may be provided in the present invention; alternatively, the suction band 38 may be supported by a vertically movable arrangement so the amount of 1 tobacco removed can be varied while maintaining the trimming discs in 2 fixed positions. Another possibility is that the suction level may be varied 3 to compact the filler stream by a varying amount. Figure 4 shows an alternative arrangement involving a disc 30 5 which lies in a vertical plane and supports one side of a filler stream 32 6 while it is being trimmed by a second disc 34 lying in a plane parallel to a 7 suction band 36. In this example the disc 30 has a purely circular edge β and extends below the filler stream. For dense ending purposes, the 9 disc 34 has circumferentially spaced pocket-forming portions 34A, and ιo excess tobacco is removed with the help of a rotary brush 38 formed a with inclined vanes 40; the brush may be positioned with its periphery i2 close to the general p lane of the disc 34, and be formed with i3 circumferentially spaced recesses to accommodate the pocket-forming i portions 34A. is The trimming height is controlled by moving the disc 34 and brush i6 38 up and down, for example in response to a neucleonic scanner i7 detecting the density of the finished cigarette rod; alternatively, the disc is 34 and brush may be set at fixed heights and weight control may be i9 achieved, for example, by controlling the height of the band 36 (the 2o portion in the vicinity of the trimming device). 2i Instead of the disc 34 reaching only to the right-hand face of the 22 disc 30, it may extend across the disc 30, which would then be 2 3 appropriately reduced in diameter. The periphery of the disc 30 may 2 then have larger-radius portions which mesh with the pocket-forming 2 5 portions 34A of the disc 34. ∑6 With this modification of the Figure 4 arrangement, the axis of the 2 7 brush 38, while remaining parallel to the plane of the disc 34, may be 28 inclined so as to project the discarded tobacco laterally away from the 29 tobacco remaining on the suction band 36. 30 The disc 30 may in each case have a diameter equal to or 3i approximately equal to that of the disc 34. 32 In a variation of the trimming device shown in Figure 4, the disc 30 33 may be lowered relative to the suction band 36 such that its axis of 34 rotation is disposed below the plane of the disc 34 and its edge at its 35 highest point is adjacent to the suction band and/or a side rail (not 36 shown) which may cooperate with the disc in supporting a side of the 37 filler stream 32. In the event that the disc cooperates with a side rail in 38 supporting a side of the filler stream in the region where trimming 1 occurs, the side rail supports the filler stream adjacent to the suction 2 band and the disc supports the stream over the remainder of the depth 3 of that side region. In this arrangement, the disc 34 may be provided with 4 fins or deflectors spaced on a circumference disposed radially inwardly 5 of the edge of the disc. The fins would be positioned and angled so as to 6 brush away the tobacco which is removed from the filler stream by the 7 disc 34. It will be appreciated that in such an arrangement, a separate s brush 38 is not required and that the fins may be staggered on two 9 different circumferences so as to accommodate the pocket-forming ιo portions 34A if the disc 34 is provided with such portions. ii Figure 5 shows another possibility. This arrangement is similar to i2 Figure 4, except that the side of the filler stream during trimming is i3 supported by a band 42, in place of the disc 30 in Figure 4. The band i4 runs around pulleys 44 and 46 and is backed by a guide member 48. is Before and after trimming, the filler stream is supported at its sides by i6 rails 50 and 52. Whereas the rail 50 is interrupted to allow the band 42 to i7 support the filler stream during trimming, the rail 52 is merely cut away to is allow the lower portion of the filler stream to be reached by the trimming i9 disc 34. 20 One of a number of dense-ending pockets 34A is shown in the 2i disc 34 in Figure 5. 22 A brush may be provided, as mentioned above, to project the 23 discarded tobacco away from the tobacco remaining on the suction 24 band. 25 In each of the examples described above with reference to 26 Figures 4 and 5, the disc 34 may be formed with a pattern of apertures in 27 the region where it contacts the tobacco, so as to allow air streams to 28 pass through the disc, namely air streams induced by the suction 29 applied through the band. 30 In each of the examples described above, weight control may, 3i instead of being achieved by vertical movement of the trimming device 32 or suction band, result from control of the level of suction in the suction 33 chamber above the band, the filler stream being thus compacted to a 34 variable extent. Dense ending may be achieved by locally compacting 35 portions of the filler stream at a location upstream of the trimming device, 36 for example as described in our PCT patent application No. GB96/00533 37 (Publication No. WO 96/27304). 38 Figure 5 also shows a second rod-making track 54 parallel and similar to the arrangement just described. For trimming purposes, a disc 56 and band 58 are provided, in staggered positions with respect to the corresponding parts of the trimmer for the first track, and these form mirror images of the arrangement described above with respect to the first track. The trimming devices described in this application are particularly suitable for twin-track cigarette making machines and allow the two suction bands to be close together and at the same level.

Claims: l Claims 2 3 1. A trimming device for trimming a cigarette filler stream 4 supported by an endless band in a cigarette making machine, said 5 device comprising a first continuously movable part arranged for 6 supporting a side region of said filler stream over at least a portion of the 7 depth of the stream and to be movable at substantially the same speed β as the stream, and a second continuously movable part arranged such 9 that an edge thereof can be moved obliquely across said band towards ιo said side region of the stream supported by the first part so as to remove a excess tobacco from said filler stream. 12 i3 2. A device as claimed in claim 1 , wherein said first part is a i4 rotatable disc arranged such than an axis of rotation thereof is disposed is above and transverse to the band, and parallel to the plane of the band. 16 i7 3. A device as claimed in claim 2, wherein said second part is is a rotatable disc arranged such that an axis of rotation thereof is i9 substantially parallel to the plane of said band and extends obliquely 20 across said band such that said edge extends obliquely across the band. 21 22 4. A device as claimed in claim 3, wherein each said disc has 23 regularly spaced recesses disposed around the periphery thereof which 2 recesses mesh such that said filler stream is trimmed so as to have 25 regularly and alternately spaced portions of greater and lesser depth. 26 27 5. A device as claimed in claim 4, wherein said second disc 28 has a larger diameter than said first disc and said discs are rotatable at 29 the same speed whereby, in use, said edge of said first disc where it 30 engages the filler stream has a velocity component in the direction of 3i movement of the band which is substantially equal to the velocity of the 32 band. 33 34 6. A device as claimed in claim 1 , wherein said first part 35 comprises an endless band. 36 37 7. A device as claimed in claim 2 or 6, wherein said second 38 part is a rotatable disc arranged to lie in a plane parallel to the plane of l the band and to extend across the width of said filler stream. 2 3 8. A device as claimed in claim 7, wherein said second disc 4 defines a plurality of regularly spaced recesses arranged such that in 5 use said filler stream is trimmed so as to have regularly and alternately 6 spaced portions of greater and lesser depth. 7 8 9. A device as claimed in claim 7 or 8, comprising brush 9 means arranged to direct said excess tobacco away from said band. 10 li 10. A device as claimed in claim 9, wherein said brush means i2 comprises a rotatable member having a plurality of inclined vanes i3 disposed around the periphery thereof. 14 is 11. A device as claimed in claim 1 , wherein said first part i6 comprises a rotatable disc arranged such than an axis of rotation thereof i7 is disposed below and transverse to the band, and parallel to the plane is of the band and said second part comprises a rotatable disc arranged to i9 lie in a plane parallel to the plane of the band and to extend across the 20 width of said filler stream. 21 22 12. A device as claimed in claim 11 , wherein said second disc 23 is provided with a plurality of circumferentially spaced apart projections 24 disposed on the side of the disc which supports said side region of the 25 filler stream, said projections being arranged for directing said excess 26 tobacco away from said band. 27 28 13. A device as claimed in claim 1 1 or 12, comprising a 29 non-movable member cooperable with said first disc for supporting said 30 side region of the filler stream. 31 32 14. A trimming device for trimming a cigarette filler stream in a 33 cigarette making machine while it is being carried by a suction band, 3 comprising a first continuously moving part which moves adjacent to one 35 side of the filler stream and at substantially the same speed, and a 3 6 second continuously moving part having an edge which moves obliquely 37 across the filler stream, towards the side thereof which is supported by 38 the first moving part, so as to remove excess tobacco. 15. A device as claimed in any one of the preceding claims, wherein said band is arranged to be movable in directions transverse the lengthwise direction thereof whereby the amount of tobacco removed by said first and second parts can be selectively varied. 16. A twin track cigarette machine comprising two suction bands arranged in parallel spaced apart relationship and, associated with said bands, respective trimming devices as claimed in any one of the preceding claims.

Inventors: DANN MICHAEL JAMES, DANN, MICHAEL, JAMES
Applicants: DANN MICHAEL JAMES, MOLINS PLC, DANN, MICHAEL, JAMES
Application year: 1998
Main classification: A24C5
IPC codes: A24C5