CIGARETTE MAKING MACHINE

Abstract: A combined shoe and tongue device for a cigarette making machine defines a tobacco receiving through-passage which has a rectangular cross section at its upstream end (18A), which cross section then changes rapidly along a relatively small proportion of the total length of the through-passage, to a rounded concave section, and the rounded section (24) then changes progressively to section (26) by way of reducing its width while retaining substantially its height. The important feature of maintaining the height while reducing the width of the filler stream may also be used in other arrangements described in the specification.

Description: l Cigarette Making Machine 2 3 Cigarette making machines commonly operate by forming a filler « stream of tobacco on the underneath surface of a suction band which 5 delivers the filler stream into a rod-forming device commonly referred to e as a "garniture". Within the garniture area of the machine the filler stream 7 is received on a continuous paper web which is carried through the β garniture by a garniture tape. The filler stream is commonly removed 9 from the suction band with the aid of a shoe and is then progressively ιo compressed and shaped by a tongue to the cross-section which it takes ιι in a finished cigarette rod, and the paper web is folded around the filler i2 stream by means of longitudinally extending folders and is then sealed to i3 form the wrapper of a continuous cigarette rod. i4 Examples of such cigarette making machines are the Molins Mark is 9, Mark 10 and Passim machines. A diagrammatic illustration of one is form of machine layout is shown in our US patent No. 4,207,907. i7 It has been common until now to make the shoe and tongue as is separate parts. The shoe assists the removal of the filler stream from the i9 suction band, effectively by a form of scraping action, and then begins 20 the compressing and shaping of the filler stream. At its downstream end 2i the shoe abuts against the upstream end of a tongue which continues 22 the progressive compressing and shaping of the filler stream. With such 23 an arrangement, the filler stream is commonly released slightly as it u leaves the shoe and enters the tongue to ensure that there is no edge at 25 the entry to the tongue on which tobacco can catch. 26 The present invention is concerned particularly, but not 27 exclusively, with an integrated shoe and tongue construction. A 28 combined shoe and tongue according to this invention may be made in 2 one piece; alternatively, if different materials are required for the two 30 parts, they may be made separately and be joined together, preferably 3i before being machined so that the underneath surface which contacts 32 the tobacco is continuous. 33 According to one aspect of the present invention there is 34 provided, a combined shoe and tongue device which defines a 35 tobacco-receiving through-passage having a rectangular cross- section 36 at its upstream end which changes rapidly along a relatively small 3 proportion of a total length of said through-passage to a rounded 38 concave cross-section, said rounded section changing progressively 1 along at least part of the remainder of the through-passage by way of 2 reducing its width whilst retaining a substantially constant height. 3 Expressed differently, the device compresses the tobacco progressively, along most of the length of the device extending to its downstream end, 5 by reducing the width of the filler stream, the height of the filler stream e having been reduced to its desired value relatively rapidly in the region 7 of the upstream end of the device. β Preferably said shoe comprises up to approximately 15 per cent 9 of said total length. ιo Advantageously said shoe comprises approximately 10.5 per n cent of total length. i2 By way of example, a device according to this invention serving as i3 both a shoe and a tongue may have a total length of, for example, 144.4 i4 mm. The upstream end portion in which the internal cross-section is changes from a rectangular to a rounded shape and reduces in height is may be approximately 15mm in length and is preferably not significantly i7 more than 20mm in length. Over that section of the device the height of is the filler stream may be reduced from, for example, 8.5mm to 7.1mm. i9 Thereafter, the rounded internal cross section may, for example, initially 20 have a radius of 5.15mm, with a width of 9.4mm, and the internal radius 2i may then reduce progressively, for example, to a final value of 22 approximately 3.45mm. Having regard to the clearance between the 23 tongue portion and the wrapper web, the height of the filler stream 24 throughout the major downstream portion of the device may be 25 approximately 7.1 mm, as previously mentioned. 26 According to another aspect of this invention, an apparatus for 27 use in forming a continuous cigarette rod is adapted to progressively 28 shape a stream of tobacco to a desired cross-section for a finished 29 cigarette rod by compressing said tobacco stream such that the height 30 of said tobacco stream is reduced to a desired value in an upstream 3i portion of the apparatus and downstream of said upstream portion the 32 width of said tobacco stream is reduced while said desired height value 33 is substantially retained. 34 The apparatus may comprise a suction band for carrying said 35 tobacco stream, a shoe disposed downstream of said suction band for 36 removing said tobacco stream from said suction band and a tongue 37 extending downstream from said shoe, wherein said upstream portion 38 comprises at least in part a downstream end region of said suction band. 1 In this arrangement the suction band may be arranged to reduce the 2 height of the tobacco stream to the desired value. Means may be 3 provided for causing the suction band to become concave at least in said downstream region adjacent said shoe. 5 In a preferred embodiment the apparatus comprises a shoe and a 6 tongue disposed downstream of said shoe, said tongue having a 7 rectangular cross-section at its upstream end and being adapted to β reduce the height of said tobacco stream to said desired value and said tongue having a rounded concave cross-section and being adapted to ιo progressively reduce the width of said tobacco stream while said desired u height value is substantially retained. Advantageously, the shoe and i2 tongue are integrated as described above. i3 This invention includes a method of shaping a stream of tobacco i in the manufacture of cigarette rods, the method comprising the steps of is reducing the height of said tobacco stream to a desired value and then i6 progressively reducing the width of said stream to a desired value whilst i7 substantially retaining said desired height value, is Preferably, during said step of reducing the height of said tobacco i9 stream the stream is changed from a generally rectangular cross-section 20 to a generally rounded cross-section. 2i Preferably the step of reducing the height of said tobacco stream 22 is relatively short in proportion to the total time taken to reduce the height 23 and width of said stream the respective desired values. 24 Preferably the step of reducing the tobacco stream to the desired 2 height does not take significantly more than 15 per cent of said total time 26 and in use of the preferred embodiment the time taken is approximately 2 10.5 per cent of the total time. 2β According to yet another aspect of the invention, a tobacco 29 conveying apparatus for a cigarette machine comprising a suction band 30 having a downstream end region, wherein at least at said downstream 3i end region thereof said suction band has a generally concave 32 cross-section. 33 An example of a combined shoe and tongue arrangement 3 according to this invention is shown in the accompanying drawings. In 35 these drawings: 36 Figure 1 is a partly sectioned view of part of a cigarette making 37 machine and shows the upstream end of the shoe/tongue device; 38 Figure 2 is an underneath perspective view of the upstream end of i the device; 2 Figure 3 is a diagrammatic side view of the whole of the device; 3 Figure 4 illustrates the changing cross-section of the device; and 4 Figure 5 shows a modified arrangement. 5 Figure 1 shows a cigarette filler steam 10 being carried by a β suction band 12 onto a paper wrapper 14 supported by a garniture tape 7 (not shown), the position of the wrapper and tape being shown a approximately in Figure 1. The suction band 12 returns around an end 9 pulley 1 6. Its path towards the end pulley is slightly downwardly ιo inclined, for example by approximately 6°, whereas the paper wrapper ιι and garniture tape in that region move horizontally. i2 The suction applied through the band 12 to hold the filler stream i3 on the band terminates just before the filler stream arrives on the i wrapper web. However, it is nevertheless necessary for the filler stream is to be scraped from the band by a shoe portion 18 of a device according i6 to this invention. For this purpose the part 18 has a horizontal edge 18A i7 at its upstream end which lies close to the band at a position just beyond is a vertical plane containing the axis of rotation of the pulley 16. i9 The underneath shape of the shoe portion is most clearly shown 20 in Figure 2. It includes sides 18B and 18C which converge while an 2i upper surface 18D drops progressively in height from an initial height 22 above the paper 14 of 8.5mm at 18A to a height of 7.1 mm at 18E along a 23 distance of, for example, 15.212mm as shown in Figure 3. In the 24 lengthwise direction thereof, the surface 18D is inclined at an angle of 25 approximately 5° to the garniture tape and paper 14. From the central 26 point 18E onwards, the height of the underneath surface of the 27 shoe/tongue device at its centre line remains constant at 7.1mm, again 28 as shown in Figure 3. 29 Figure 2 shows an interface 20 between the shoe portion 18 and a 30 tongue portion 22 of the device. This applies if it is desired that the shoe 3i and tongue portions be made of different materials. However, even if 32 that applies, the two portions 18 and 22 are preferably secured by 33 welding or in some other way to an overhead device 23 before the 34 underneath surface of the shoe/tongue is machined. Thus there is no 35 abrupt change of cross-section immediately before and after the 36 interface 20. However, the shoe and tongue portions 18 and 22 are 37 preferably made in one piece, for example of tungsten carbide. 38 As shown by Figure 3, in the case of a device having a total length 1 of 144.4mm, the height of the filler stream is reduced along only a small 2 proportion of that total length, for example approximately 15mm, and 3 thereafter remains constant. However, the height reduction may 4 alternatively occur over a slightly longer distance, for example up to s approximately 20mm, but the height nevertheless preferably remains e constant along most of the length of the device. 7 Figure 4 shows, by way of example, how the cross-section or β shape of the device may change. The initial shape at the upstream edge 9 18A is rectangular, as shown by the dotted outline. Where the internal ιo shape becomes round (i.e. just beyond the point 18A, as can be seen in ιι Figure 2) it corresponds to the chain-dotted outline 24 and its highest i2 point is at a distance D below the level of the edge 18A of, for example, i3 1.4mm. The concave shape 24 then changes progressively to the shape i4 26 shown in continuous outline, which is the shape at the downstream is end of the tongue. As shown in Figure 4, the initial curved cross-section i6 represented by the chain-dotted outline 24 has a radius of 5.15mm and a i7 width of 9.4mm. The radius reduces progressively to 3.45mm and thus is reduces the width of the filler stream progressively to a final value of i9 approximately 7mm, the shape of the tongue at its downstream end 20 being very close to a semi-circle. The width of the filler stream as it 2i leaves the tongue may in practice be approximately 7.1 mm for a 22 cigarette rod diameter of 7.9mm. 23 Although not shown in the drawings, it should be understood that 24 the garniture tape (and hence the paper wrapper) is slightly concave in 25 cross-sectional shape at the point at which the filler stream is deposited 26 on the paper wrapper. Then, as the filler stream is progressively 27 compressed and narrowed by the shoe/tongue device, the garniture 2β tape is constrained by a garniture bed to become progressively more 29 deeply and narrowly concave so as to form the paper wrapper ultimately 30 into a U-section with a rounded bottom surface and a width of 3i approximately 7mm. Beyond the downstream end of the shoe/tongue 32 device, the upstanding edges of the paper wrapper are folded over by 33 the conventional folding devices and the edges of the paper are then 34 sealed in the usual way to form a continuous cigarette rod. The 35 continuous rod is then cut at regular intervals to form discreet cigarette 36 rod lengths in the usual way. 3 The invention described above with respect to a combined shoe 38 and tongue can also be applied to a separate shoe and tongue 1 arrangement. That is to say, the shoe is arranged to change the 2 cross-section of the filler stream from rectangular to round while 3 reducing its height, and the upstream end of the tongue has internal 4 dimensions slightly greater than those of the downstream end of the 5 shoe to ensure that tobacco cannot catch on any edge of the tongue, e the internal height of the tongue remaining substantially constant while 7 the width decreases to compress the tobacco sideways. β While starting up the machine, it is preferable to thread the paper into the garniture while the machine speed is still relatively low. ιo According to another aspect of this invention, the height reduction a of the filler stream may be effected entirely or mainly by the suction band i2 as it conveys the filler stream towards the horizontally moving garniture i3 tape. The internal height of the shoe/tongue, or of the shoe and tongue i4 if they are separate items, could then remain substantially constant while is the cross-sectioned shape changes from rectangle to round and then i6 becomes progressively narrower. i7 A further possibility following on from the last-mentioned aspect of is this invention is illustrated by Figure 5. In this example a continuous i9 cigarette filler stream 30 (only partly shown) is carried by a suction band 20 32 which, in the region of the garniture, passes around three pulleys 2i 34,36 and 38. The pulleys 34 and 38 have cylindrical peripheries, but 22 the pulley 36 has a concave peripheral cross-section so that the suction 23 band becomes concave as it approaches the pulley 36 and thus begins 24 the rounding of the top surface of the filler stream. The centre line of the 25 suction band as it passes from the pulley 34 to the pulley 36 is preferably 26 downwardly inclined so as to compress the filler stream vertically in 27 cooperation with the garniture tape 40. A shoe/tongue 42 (or shoe ∑β followed by a separate tongue) removes the filler stream from the suction 29 band in the region of the pulley 36, for which purpose its upstream edge 30 has a curve corresponding to that of the suction tape at that position. 3i The shoe/tongue (or shoe) could initially continue the vertical 32 compression of the filler stream along a short distance or, if the filler 33 stream is sufficiently compressed vertically by the suction band, the 34 shoe/tongue could simply act to compress the filler stream sideways in 35 the manner described with reference to Figures 1 to 4. 36 The curving of the suction band (which may be of woven nylon) is 37 facilitated by the fact that the band has only a small angle of wrap around 38 the pulley 36. This feature is useful in its own right and can be used also with other forms of shoe/tongue or shoe and tongue arrangements.

Claims: l Claims: 2 3 1. A combined shoe and tongue device which defines a 4 tobacco receiving through-passage having a rectangular cross-section s at its upstream end which changes rapidly along a relatively small 6 proportion of a total length of said through-passage to a rounded 7 concave cross-section, said rounded section changing progressively β along at least part of the remainder of the through-passage by way of 9 reducing its width whilst retaining a substantially constant height. ιo 2. A device as claimed in claim 1 , wherein said shoe and ιι tongue are defined by a single piece of material. i2 3. A device as claimed in claim 1 or 2, wherein said shoe i3 comprises up to approximately 15 per cent of said total length. i4 4. A device as claimed in claim 3, wherein said shoe is comprises approximately 10.5 per cent of said total length. i6 5. A device as claimed in any one of claims 1 to 4, wherein i7 said rounded section changes progressively to a substantially is semi-circular cross-section. i9 6. Apparatus for use in forming a continuous cigarette rod, 20 said apparatus being adapted to progressively shape a stream of 2i tobacco to a desired cross-section for a finished cigarette rod by 22 compressing said tobacco stream such that the height of said tobacco 23 stream is reduced to a desired value in an upstream portion of the 24 apparatus and downstream of said upstream portion the width of said 25 tobacco stream is reduced while said desired height value is 26 substantially retained. 27 7. Apparatus as claimed in claim 6, comprising a suction band 28 for carrying said tobacco stream, a shoe disposed downstream of said 29 suction band for removing said tobacco stream from said suction band 30 and a tongue extending downstream from said shoe, wherein said 3i upstream portion comprises at least in part a downstream end region of 32 said suction band. 33 8. Apparatus as claimed in claim 7, wherein said suction 34 band is arranged to reduce the height of said tobacco stream to said 35 desired height value. 36 9. Apparatus as claimed in claim 7 or 8, further comprising 37 means for causing said suction band to become concave at least in said 38 downstream end region adjacent said shoe. 1 10. Apparatus as claimed in claim 6, comprising a shoe and a 2 tongue disposed downstream of said shoe, said shoe having a 3 rectangular cross-section at its upstream end and being adapted to 4 progressively reduce the height of said tobacco stream to said desired 5 value and said tongue having a rounded concave cross-section and 6 being adapted to progressively reduce the width of said tobacco stream 7 while said desired height value is substantially retained. β 11. Apparatus as claimed in claim 10, wherein said tongue and 9 shoe are combined having been made in one piece. ιo 12. Apparatus as claimed in claim 10, wherein said tongue and ιι shoe are separate parts joined together and having respective surfaces i2 for shaping said tobacco stream, said surfaces having been machined i3 together so as to define a continuous tobacco shaping surface. i4 13. Apparatus as claimed in claim 10, 1 1 or 12, wherein at a is downstream end region thereof said rounded section is substantially i6 semi-circular. i7 14. A method of shaping a stream of tobacco in the is manufacture of cigarette rods, the method comprising the steps of i9 reducing the height of said tobacco stream to a desired value and then 20 progressively reducing the width of said stream whilst substantially 2i retaining said desired height value. 22 15. A method as claimed in claim 14, wherein during said step 23 of reducing the height of said tobacco stream the stream is changed 24 from a generally rectangular cross-section to a generally rounded 25 cross-section. 26 16. A method as claimed in claim 14 or 15, wherein said step of 27 reducing the height of said tobacco stream is relatively short in 28 proportion to the total time taken to reduce the height and width of said 29 stream to the respective desired values. 30 17. A method as claimed in claim 16, wherein said step of 3i reducing the height of said tobacco stream to said desired value takes 32 up to approximately 15 per cent of said total time. 33 18. A method as claimed in claim 17, wherein said height 34 reducing step takes approximately 10.5 per cent of said total time. 35 19. A method as claimed in any one of claims 14 to 18, wherein 36 said stream has a substantially circular cross-section when said desired 37 width value is attained. 38 20. Tobacco conveying apparatus for a cigarette machine i comprising a suction band having a downstream end region, wherein at 2 least at said downstream end region thereof said suction band has a 3 generally concave cross-section.for a cigarette machine comprising a suction band having a downstream end region, wherein at least at said 5 downstream end region thereof said suction band has a generally 6 concave cross-section. 7 21. A cigarette making machine comprising apparatus as s claimed in claim 20 and a tongue and shoe device, wherein an upstream 9 end of said shoe has a concave cross-section corresponding ιo substantially to the cross-section of a downstream end of said suction ιι band. 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32. 33 34 35 36 37 38

Inventors: DAWSON JOHN, DYETT DEREK HENRY, RUTLAND ROBERT THOMAS, SHARP NORMAN LINDSEY, DAWSON, JOHN, DYETT, DEREK, HENRY, RUTLAND, ROBERT, THOMAS, SHARP, NORMAN, LINDSEY
Applicants: DAWSON JOHN, DYETT DEREK HENRY, MOLINS PLC, RUTLAND ROBERT THOMAS, SHARP NORMAN LINDSEY, DAWSON, JOHN, DYETT, DEREK, HENRY, RUTLAND, ROBERT, THOMAS, SHARP, NORMAN, LINDSEY
Application year: 1997
Main classification: A24C5
IPC codes: A24C5