METHOD AND APPARATUS FOR WRAPPING A ROD OF SMOKING MATERIAL

Abstract: The effect of spiral-wrapping of a tobacco rod is obtained by providing a wrap material (1) having edge portions (3) which are angled to an edge (4) which is to be arranged axially of the tobacco rod when the material is wrapped cylindrically around the tobacco. Discontinuities (5) between inclined edge portions (3) are preferred positions for the severing of rods wrapped with the material, into cigarette lengths. Methods and apparatus are disclosed for wrapping or overwrapping with this material to form the tobacco rod.

Description: METHOD AND APPARATUS FOR WRAPPING A ROD OF SMOKING MATERIAL The present invention relates to a method and apparatus for manufacturing a rod of tobacco or other smoking material enclosed by a wrap (hereinafter "tobacco rod") . It is especially concerned with tobacco rods having a spiral-effect outer wrap and a method and apparatus for producing these. Cigarettes are commonly wrapped in paper by placing a line of tobacco along a paper strip, in parallel alignment with the edges of the strip, enclosing the smoking material in the paper strip by bringing its edges together and sealing them together to form a rod having a longitudinal seam in its paper. Cigar-style products are commonly provided with a spiral wrap of tobacco leaves or reconstituted tobacco material. The machinery required to spiral wrap a tobacco rod is more complex than that used for parallel wrapping because either the rod, or the outer wrap material must be rotated relative to the axis of the rod to achieve the spiral . One known method of providing a spiral wrap to a cigar style product is to roll a double length tobacco rod onto a chevron-shaped piece of outer wrap material to give a double length spirally wrapped tobacco rod with a left hand and a right hand spiral. This is then cut in half to give two cigars. A second known method to produce a spiral outer wrap rotates smoking material rods, pre-wrapped in a binder or inner wrap, about their longitudinal axis between two endless belts running in opposite directions. The rod is set at an angle to the belts so that as it spins, it also moves forward along its axis. A web of outer wrap material is fed, parallel to the belts, to wrap around the rod as it advances. The spirally wrapped rod is then cut to the required length. Another known method of spirally wrapping a smoking material rod involves passing the rod through the middle of a bobbin of outer wrap material, at an angle to the axis of the bobbin, and rotating the bobbin around the rod. The rod is spirally wrapped by outer wrap material taken from the bobbin. A problem with this method is that control is complicated by the changing inertia and speed of the bobbin as the wrap material unwinds from it . An object of the present invention is to achieve a non-parallel wrap effect in a simpler and more efficient way . According to a first aspect, the present invention provides a method of wrapping a rod of smoking material to give a non-parallel wrapped effect, which includes wrapping the rod in a parallel wrap binder, guiding at least one extension, integral with or attached to the binder and having at least one edge at an angle to the axis of the rod to overlie the binder on the surface of the rod, so that the inclined edge gives a non- parallel line, securing said at least one extension to conform to the binder on the rod, and separating the wrapped rod into discrete lengths. In preferred embodiments, a plurality of extensions each have at least one inclined edge, there being a discontinuity between inclined edges of adjacent extensions. In such embodiments, the wrapped rod may be divided into discrete lengths at the discontinuities. When the inclined edge is straight, a spiral wrap effect is obtained. Since the guiding is essentially a wiping motion it can be done by static parts (by virtue of the axial motion of the rod through the machine) ,- even if a rotating wiper is provided to cause the extension to conform it does not have to contain or feed sheet material. When the extensions are non-integral, they may be attached to the binder before, during or after the formation of the parallel wrap. In one such method, discrete lengths of outer wrap material are severed from a web of outer wrap material and affixed to a binder pre-wrapping a rod of smoking material, to form the extensions which project from the rod at an angle to its longitudinal axis. The projecting sheets are then guided around the rod to provide the wrap effect. In a second aspect, the present invention provides an apparatus for wrapping a rod of smoking material comprising means for wrapping the rod in a parallel-wrap binder and means for guiding around the rod at least one extension of wrap material projecting from the parallel wrapped rod and having at least one edge inclined at an angle to its longitudinal axis. In one embodiment, the means for guiding comprise a paddle rotatable about the rod to guide the projecting sheets of outer wrap material around the rod. As the guide means rotate around the axis of the rod, the rod moves forward along its longitudinal axis. In this manner, the projecting extensions of outer wrap material may be guided into a spiral formation around the rod. In an alternative embodiment, the means for guiding comprise a plough turner having a trough or tube through which a tobacco rod may be passed, the trough or tube having a spiral wall, edge or slot to guide the at least one edge of a projecting extension around the rod as the rod advances. The apparatus according to the invention may be provided by adapting known cigarette or cigar wrapping machinery, or may be provided as a separate machine at the end or in the middle of a conventional cigar or cigarette manufacturing machine. Glue may be applied to the projecting sheets of outer wrap material before or during guiding to form the spiral effect wrap. In a third aspect, the present invention provides a web of wrap material for wrapping a rod of smoking material comprising a parallel wrap binder and at least one extension from a parallel binder forming portion thereof, the extension having at least one inclined edge. Where there are a plurality of extensions, there may be discontinuities between the inclined edges of adjacent extensions. The extensions may be integral with the binder, or affixed thereto. Embodiments of the invention will now be described in more detail, by way of example only, with reference to the following drawings in which:- Fig. 1 shows a portion of a web of wrap material suitable for use in the present invention, having integral binder portion and angled projections; Fig. 2 shows a second form of wrap material suitable for use in the present invention in which projections are formed by separate strips pre-glued onto a binder portion; Fig. 3 shows a further form of wrap suitable for use in the present invention in which separate angled strips of outer wrap material are affixed to a binder portion pre-wrapped around a tobacco rod; Fig. 4 shows a portion of a conventional machine for wrapping a tobacco rod, adapted according to the invention; Fig. 5 shows the machine of Fig. 1 from the side; Fig. 6 is a cross-section taken along line III- III of Fig. 2; Fig. 7 is a cross-section taken along line IV-IV of Fig. 2; Fig. 8 is a cross-section taken along line V-V of Fig. 2; Fig. 9 is a cross-section taken along line VI-VI of Fig. 2; Fig. 10 is a cross-section taken along line VII- VII of Fig. 2; Fig. 11 is a cross-section taken along line VIII-VIII of Fig. 2; Fig. 12 is a side elevation of a plough turner, suitable for use in apparatus according to the invention; Fig. 13 is an end view of the plough turner of Fig. 12; Fig. 14 is a cross-section of the plough turner of Fig. 12 taken along line XIV-XIV; Fig. 15 is a cross-section of the plough turner of Fig. 12 taken along line XV-XV; Fig. 16 is a cross-section of the plough turner of Fig. 12 taken along line XVI-XVI; Fig. 17 is a cross-section of the plough turner of Fig. 12 taken along line XVII-XVII; and Fig. 18 is an isometric drawing of spiral wrapping apparatus according to the invention situated in the middle of a conventional cigarette manufacturing machine. In the subject invention, a spiral-effect outer wrap may be provided for a pre-formed tobacco (or other smoking material) rod which already has a wrap of binder material, or a rod may be formed and wrapped in one process. In both cases, a conventional cigarette wrapping machine can be adapted to provide the spiral wrap. Figs. 1 and 2 show two forms of wrap which may be used when the rod is formed and wrapped in one action. A sheet material used for cigarette wrapping is in the form of a web 1,1' having a binder region 2,24 having a free edge 4 and a parallel notional edge 6, thus being equivalent to a conventional parallel-sided web of cigarette wrap paper and forming a parallel wrap about the smoking material. However, extending therefrom are extensions 8 (which in Fig. 2 are provided by separate sheets 26 attached to the binder region 24) having an inclined straight edge 3, angled away from the parallel binder edges 4,6. Between successive extensions 8 are saw-toothed discontinuities 5, where one inclined edge 3 stops and the next begins. When the extensions 8 are guided around the rod, the inclined edges 3 form a spiral effect which stops at the discontinuity 5. The rod may then be divided into lengths, preferably at the discontinuities, each length, having an inner parallel wrap provided by the binder region 2,24 and an outer, spiral effect wrap provided by the extensions 8. The length and angle of the edge 3 may be such as to provide one, or more than one, helical turn in the length of each finished separated rod. When the webs 1 of wrap material are used in a combined rod forming and wrapping process, tobacco or other smoking material 7 is deposited (see Fig. 5) on the binder portion 2,24 of the wrap material 1 of Fig. 1 or Fig. 2, which is supported and transported from a reel of wrap material (not shown) by a garniture tape 10 supported on two rollers 11. The wrap material is guided through a guide trough 12 of mainly semi-cylindrical cross-section formed in a support body 14, and the tobacco 7 is compressed within the trough 12 by a concave pressure finger 16 (Figs. 4-7) to form the tobacco rod 17. As the wrap material 1 and compressed tobacco 7 pass along the trough 12, guiding wall elements 18,20 gradually raise the longitudinal edges of the wrap material (Figs. 6-8) to enclose the tobacco, as in a conventional cigarette making machine. Glue is applied by a nozzle 23 (Fig. 9) along the parallel glue line 6 of the binder portion 2,24 of the wrap material 1 adjacent the projections 8 and guide means 22 hold the extensions 8 away from the tobacco rod 17. The guide walls 18,20,30 fold the binding portion 2,24 of the longitudinal wrap 1 to enclose the tobacco rod 17, the free edge 4 of the wrap material 1 being secured with the glue applied adjacent 6 the extensions 8. The glue is set by application of a heat bar 32 (Fig. 11) . At this stage, in a conventional cigarette manufacturing machine, the tobacco rods would be cut into lengths suitable for the cigarette or cigar product. They would then be transported to tipping and packaging machines as applicable. However, in the methods of the invention, this is preceded by the need to guide the projecting outer wrap sheets around the formed tobacco rod. After the binder glue has set, the extensions 8 are guided around the formed rod 17 and secured there with glue which can be applied either just before the guidance or at an earlier stage. Preferably, non-moving parts of the apparatus guide the extensions 8 as the tobacco rod 17, enclosed by the binding portion 2,24 of the wrap 1, moves longitudinally through the wrapping apparatus supported by the garniture tape 4. One way in which this can be achieved is by plough turning. In this process the tobacco rod 17 moves along a guide channel 40 of a plough turner (Figs. 12-17) one wall 42 of which defines a spiral and which guides the extensions 8 spirally around the rod 17. Glue may be applied to the extensions 8 as the rod 17 moves along the plough turning guide channel 40 or before the rod 17 enters the plough turner. Alternative methods of guiding the extensions around the rod include using garniture tapes or external winders. One example of an external winder is indicated by reference numeral 100 in Fig. 18. This consists of a blade 102 having a portion parallel to the tobacco rod 17 and a portion angled away therefrom, the blade 102 being rotationally mounted upon a drive unit 104 through which the tobacco rod 17 passes. Rotation of the blade 102 about the tobacco rod 17 causes the projecting sheets 8 of outer wrap material to be wrapped around the rod, as the rod 17 passes through the drive unit 104. Fig. 18 illustrates apparatus for carrying out the method in which separate strips 28 of outer wrap material are attached to a pre-made rod 17 as shown in Fig. 3 and then wound around the rod. The pre-made rod is enclosed in a binder or inner wrap before the strips of outer wrap material are attached. This may be done in a conventional cigarette making machine. As the wrapped tobacco rod 17 exits guide trough 12 of a conventional cigarette making machine, it passes under a suction drum 110 which carries pre-cut sheets, or "flags" 28 of outer wrap material. The flags 28 are removed from the suction drum 110 by garniture tape 112 which passes around the drum and under inverted guide trough 113. This so-called inverted garniture tape transfers the flags from the drum to the moving tobacco rod. The flags are cut from a web of outer wrap material 115 drawn by drive units 116 from a bobbin 114. Glue is applied to the web 115 by gluing rollers 118 and the web 115 is fed towards the suction drum 110 at an angle to its axis, passing beneath cutting roller 120, mounted parallel to the suction drum 110, which cuts rhomboid flags from the web 115. Rotary clamp 122 presses each severed flag 28 onto the garniture tape and suction drum 110. Suction from within the drum 110 acts through perforations in the drum's circumferential surface to hold the flags 28 in place. As the flags 28 come into contact with the tobacco rod 17 beneath the suction drum 110, they are attached by the previously applied glue to the rod 17 to form extensions of the binder. The flags 28 are held in place and curved around the rod as the inverted garniture tape passes through the guide trough 113, so that they project generally downward from the rod 17 as they approach the external winder 100, the action of which is described above. The spirally wrapped tobacco rod passes to cutting drum 124 and is cut at the discontinuities 5' between the extensions, into the correct lengths 125 for the desired cigarette or cigar product. Each length 125 has a spiral effect outer wrap provided by the inclined straight edge 3 of a single projecting flag 8. The lengths 125 are then passed through a series of rollers 126,128 to an end trimming roller 130 and blade 131 which may be as found in a conventional cigarette manufacturing machine. The trimmed lengths may then pass to tipping or packaging machinery, as required. Further winding means such as the plough turner described above may be fitted between the inverted garniture 112,113 and the external winder 100. The edges 3 need not be straight, so that wrapping effects other than spiral, e.g. a wavy edge, could be obtained if desired.

Claims: CLAIMS 1. A web of wrap material for wrapping a rod of smoking material comprising a parallel wrap binder and at least one extension from a parallel binder forming portion thereof, the extension having at least one inclined edge. 2. A web according to claim 1 which has a plurality of extensions, with a discontinuity at that edge between adjacent extensions. 3. A web according to claim 1 or claim 2 wherein the extensions are integral with the parallel wrap binder. 4. A method of wrapping a rod of smoking material to give a non-parallel wrapped effect, which includes wrapping the rod in a parallel wrap binder, guiding at least one extension, integral with or attached to the binder and having at least one edge at an angle to the axis of the rod to overlie the binder on the surface of the rod, so that the inclined edge gives a non- parallel line, securing said at least one extension to conform to the binder on the rod, and separating the wrapped rod into discrete lengths . 5. A method according to claim 4 wherein a plurality of extensions each have at least one inclined edge, there being a discontinuity between inclined edges of adjacent extensions, and the method includes severing the wrapped rod into discrete lengths at the discontinuities. 6. A method according to claim 4 or claim 5 wherein the extensions are integral with the parallel-wrap binder. 7. A method according to claim 4 or claim 5 wherein the extensions are non-integral with the parallel-wrap binder and wherein discrete lengths of outer wrap material are severed from a web of outer wrap material and affixed to a binder pre-wrapping a rod of smoking material, to form the extensions which project from the rod at an angle to its longitudinal axis, the projecting extensions then being guided round the rod to provide the spiral-wrap effect. 8. An apparatus for wrapping a rod of smoking material comprising means for wrapping the rod in a parallel-wrap binder and means for guiding around the rod at least one extension of wrap material projecting from the parallel wrapped rod and having at least one edge inclined at an angle to its longitudinal axis. 9. Apparatus according to claim 5 wherein the means for guiding comprise a paddle rotatable about the rod to guide the projecting sheets of outer wrap material around the rod. 10. Apparatus according to claim 5 wherein the means for guiding comprise a plough turner having a trough or tube through which a tobacco rod may be passed, the trough or tube having a spiral wall, edge or slot to guide the at least one edge of a projecting extension around the rod as the rod advances.

Inventors: BATES DAVID JOHN, BRAY ANDREW JONATHAN, LAUGHTON JONATHAN CHARLES, PARKER MICHAEL PATRICK, STEWART-COX ADRIAN ROY, BATES, DAVID, JOHN, BRAY, ANDREW, JONATHAN, LAUGHTON, JONATHAN, CHARLES, PARKER, MICHAEL, PATRICK, STEWART-COX, ADRIAN, ROY
Applicants: BATES DAVID JOHN, BRAY ANDREW JONATHAN, LAUGHTON JONATHAN CHARLES, PARKER MICHAEL PATRICK, ROTHMANS INTERNATIONAL LTD, STEWART COX ADRIAN ROY, BATES, DAVID, JOHN, BRAY, ANDREW, JONATHAN, LAUGHTON, JONATHAN, CHARLES, PARKER, MICHAEL, PATRICK, ROTHMANS INTERNATIONAL SERVICES LIMITED, STEWART-COX, ADRIAN, ROY
Application year: 1995
Main classification: A24D1
IPC codes: A24C1, A24C5, A24D1