US3779253A

US3779253A - Cigarettes

Info

Publication number: US3779253A
Application number: US00757890A
Authority: US
Inventors: F Labbe
Original assignee: Molins Machine Co Ltd
Current assignee: Molins Machine Co Ltd
Priority date: 1967-09-15
Filing date: 1968-09-06
Publication date: 1973-12-18
Anticipated expiration: 1990-12-18
Also published as: SE345376B; JPS4818839B1; DE1782547A1; FR1581862A; GB1242398A

Abstract

In tobacco feeding apparatus in a cigarette making machine, ''''shorts'''' are collected from the tobacco supply and are mixed by tumbling in a hollow rotating member such as a drum forming part of a cigarette-making machine, e.g. a main feed drum, a refuser drum, or a shorts return drum. In one embodiment shorts are fed into rotating annular sieves one within the other and mounted in a rotating drum, so that the shorts are graded as well as mixed. The mixed shorts are later incorporated in the tobacco filler.

Description

[ 1 Dec. 18, 1973 United States Patent [191 Labbe Brewster.t.............v......... 209/291 X N PATENTS OR APPLICATIONS M m H m ..n ."S mrfl l omg dm fi r GAFG 657-675 4 3256 990 999 HHHHHH 833996 9 0-i74 -L50993 .9 .350 003-3469 12 76000 .2 .3 zainla m .n a m L m m nh .mn ag u 3 mm r M 0. n e mm m me .l% S h m A w d r .w w so fl n u D. me e FN MD m E 6 R m m A w m m m C1 A l] l 4 5 3 5 7 7 [1 FOREIG A0 1 11 1A1 NOW 5 3 1 1 m .mm W 38 nun rrl F Bau wmlw rm GGP 59a 36 999 HHH 061 Foreign Application Priority Data Sept. 15, 1967 Great Britain......t............

Primary Examiner--Joseph S. Reich Att0rneyCraig, Antonelli & Hill a mmm u w mm" a O .w m CW a .m T .m g C n 5 .1 A Di R m cb T km S H U B PC... A @e amd b n 11 Ohfl 7 to 5 l b [Im o ow m 9 95 2/ W 1 ,9 2 92 2 4 3 2 79A 36 1 09 w New 0 mm 1 n l .3 uu B U m H m U W "h H "C u r U mw m W53 L C loH H3 5 um U IF n H0 0 5 55 member such as a drum forming part of a cigarettemaking machine, e.g. a main feed drum, a refuser [56] References Cited UNITED STATES PATENTS drum, or a shorts return drum. in one embodiment shorts are fed into rotating annular sieves one within the other and mounted in a rotating drum, so that the shorts are graded as well as mixed. The mixed shorts are later incorporated in the tobacco filler 6 Claims, 11 Drawing Figures PATENTE!) on: 1 8 ms shim 1n? 7 PATENTEU [15a '1 8 1975 SHLET 3 CF r A w PATENTEDUEB 18 I975 SHEET 5 [1F 7 AZ M451,

CIGARETTES This invention concerns improvements in or relating to the manufacture of cigarettes on cigarette-making machines in which a continuous tobacco filler is produced and a continuous wrapper web is folded around the tiller and has its edges sealed together to form a continuous cigarette rod from which individual cigarettes are cut off.

The cut tobacco used in the manufacture of cigarettes normally comprises a number of different types of particles; there are the long strands cut from the lamina of the tobacco leaf which constitute the major bulk of the tobacco; heavy particles which come mainly from the stems of the tobacco leaves and which are not wanted in the tobacco filler; and small particles known as shorts which consist mainly of small pieces of the tobacco lamina but which can also contain heavy stem particles which may be unwanted. These shorts have the characteristic of a lower filling power than the long strands and of constituting a more dense material than the long strands. Shorts may also be formed from the breakdown of longer strands in manipulating the tobacco to produce the filler. The quantity of shorts may be as much as thirty per cent of the tobacco flow and for economic reasons it is therefore usual to ensure that they are incorporated in the tobacco filler. They are troublesome to deal with, since they must be contained in the cigarette in such a way that they do not readily fall out, and in addition they have a considerable influence on the local density of the tobacco in which they are present and on the sensors of control devices for the machine. Moreover, in all modern machinery the tobacco filler is metered by volume and so this influence on the density has a marked effect on the weights of the individual cigarettes. In modern manufacture this is very important as one of the criteria of a good cigarette-making machine is that the cigarettes it produces have very consistent weights. In addition localised concentrations of shorts in a cigarette have a marked effect on its flavour, causing it to burn hotter and to taste more bitter.

It has been known for a long time, when forming a continuous tobacco filler by metering tobacco from a supply to produce a continuous flow of tobacco from which the tobacco filler is made, to remove shorts continuously from the tobacco so as to produce a flow of shorts which is then fed back into the tobacco at a position downstream from where it was removed.

In recent times it has been proposed in, for example, U.S. Pat. No. 3,374,795 to manipulate the shorts flow in various ways with a view to improving the quality of the cigarettes produced. However, since production speeds are always being steadily increased, with the result that the effect of the shorts on the individual weight variations is intensified, it is desirable to improve the shorts handling still further.

It is an object of the present invention to improve the handling of shorts in the production of a continuous tobacco filler, thereby to improve the manufacture of cigarettes.

According to the present invention there is provided a method of producing a continous tobacco filler which comprises feeding tobacco from a supply thereof to produce a continuous flow of tobacco from which the continuous tobacco filler is produced, and which includes continuously removing shorts from the tobacco to produce a flow of shorts, performing any number of the following shorts-manipulation steps (a) to (d):

a. rendering the distribution of different-sized particles in the flow of shorts more regular,

b. refining the shorts flow to separate it into portions of particles of different sizes, manipulating the portions of the flow to produce an improved shorts flow,

c. running the flow of shorts through the interior of a hollow rotating drum, for example a drum used in feeding the tobacco from the supply, and employing the rotation of the drum in manipulating the shorts therewithin to improve their flow,

d. winnowing the tobacco flow to remove heavy particles therefrom in a continuous flow, combining the flow of heavy particles with the shorts flow, winnowing the combined flow, thereby to incorporate in the shorts flow light particles removed from the tobacco flow with the heavy particles, and feeding the flow of shorts into the tobacco, preferably at a position downstream from where the shorts were removed.

Each of the novel steps (a) to (d) provides special advantages of significance in the manufacture of cigarettes.

It is found that even though the flow of shorts is manipulated to have a more or less regular rate, variations may still occur in the cigarette weights and that these variations are reduced by regularising the distribution of different-sized particles in the stream to tobacco from which cigarettes are produced. It would appear that the reason for this is that the shorts flow tends to be generated in pulses or waves which may have concentrations of fine or of coarse particles and that these particles have different effects on the density of the filler. In addition where the filler is trimmed to size and the trimming is controlled by air-flow test performed upstream of the trimming, inconsistencies occur between what happens with fine and what happens with coarser particles.

Having regard to the different effects which the different sizes of shorts particles have on the tobacco filler, it is of advantage to separate the flow into fractions each of one range of particle size, as these can then be handled in such a way as to allow for the particular effect of that size of particles. One example of this is to mix the fractions together, thereby achieving a more effectively mixed flow having a more random distribution of the different sizes of particles. Such a flow is more uniform in nature and therefore has a more consistent efiect on the tobacco it is mixed with. Another example of such a way of handling the different fractions is to feed them separately to different parts of the machine where they will be treated in different ways or produce different effects.

There is usually little space available in a cigarettemaking machine, so that it is difficult conveniently to position apparatus for handling shorts in the machine, particularly if the apparatus embodies drive means for imparting a regularising motion to the shorts. There is thus special advantage in manipulating the shorts in the interior of one of the carded drums used in feeding or metering the tobacco, or in any other suitable drum which has another function, since this means that no extra space is required for the shorts handling apparatus or for any drive means therefor and not only is there a valuable economy in space but the cost is reduced.

Difficulties can be experienced in combining the shorts flow with the tobacco flow. These difficulties may arise, for example, from differences in air pressure between the environments of the two flows as is the case if either one is being conveyed by air pressure means. One convenient way of returning the shorts, which tends to avoid these difficulties, is to combine them with heavy particles produced by winnowing the tobacco flow, before those heavy particles are winnowed a second time. This technique also ensures that the shorts themselves are winnowed to remove heavy particles they may contain.

Several embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings in which:

FIG. 1 is a cross-sectional view of one embodiment,

of a part of a cigarette-making machine,

FIG. 2 is a section on the line IIII of FIG. 1,

FIG. 3 is a section on the line III-III of FIG. 2,

FIG. 4 is an end view of a modified drum,

FIG. 5 is a sectional view on the lines VV of FIG.

FIG. 6 is a cross-sectional view of another embodiment of a cigarette-making machine,

FIG. 7 is a sectional view on the line VII-VII of FIG.

FIG. 8 is a sectional view on the line VIIIVIII of FIG. 6,

FIG. 9 is a cross-sectional view of a further embodiment of the invention,

FIG. 10 is an enlarged sectional view of the line X-X of FIG. 9, and

FIG. 11 is a section on the line XIXI of FIG. 10.

The cigarette-making machine shown in FIGS. 1 to 3 comprises a tobacco hopper shown in part and indicated generally at l, for a gravity-fed supply of tobacco, a housing 2 which contains apparatus to meter a continuous carpet of tobacco from the hopper 1 to further apparatus (not shown) where the tobacco carpet is formed into a continuous tobacco filler which is then enclosed in a paper wrapper and cut up into cigarette lengths by well-known apparatus none of which is shown.

The metering apparatus comprises a carded main feed drum 4, a carded refuser drum 5, a picker roller 6 and a carded shorts removal roller 7, all of which are mounted for rotation in the respective directions shown by the arrows and at appropriate speeds. In addition an endless belt conveyor 8 is provided to receive tobacco picked from the drum 4 and to carry it in the form of a carpet to the filler-forming apparatus.

Just beneath the shorts removal roller 7 and extending along the length of that roller there is an outlet chute 9 down which shorts are discharged to an air duct 10 by means of a vaned roller 11. A pipe 12 connects the duct 10 with the interior of the main feed drum 4, which is hollow, through one wall of the housing 2 at one end of the drum. A transfer chute 13 is formed in the opposite wall of the housing 2 at the other end of the drum 4 to provide communication between the interior of the drum and a vibrating tray 14, which is positioned below the main feed drum 4 to deliver shorts on the conveyor 8 in a region nearer one side of the conveyor than the other, see FIG. 2.

The hollow main feed drum 4 is formed internally with a series of axially extending ribs 15 which slope from that end of the drum which communicates with the pipe 12, almost up to the other end where the transfer chute 13 is disposed. Adjacent that end, the interior of the drum is a smooth sloping surface 51 to enable the shorts to flow regularly out of the drum. Cross struts 16 support the main feed drum 4 on a shaft 17. A deflector plate 18 is secured to the frame 2 over the mouth of'the pipe 12 within the drum 4 to direct the incoming shorts flow into the inlet end portion of the drum.

In operation the main feed drum 4 rotates in an counterclockwise direction as viewed in FIG. 1, and draws a carpet of tobacco out of the hopper 1. This carpet is levelled off by the refuser roller 5 and tobacco is then picked off the main feed drum 4 by the picker roller 6 and showered on to the upwardly moving conveyor 8 whence it is transferred for forming into the tobacco filler and then cigarettes as has previously been described.

Not all the tobacco is removed from the main feed drum 4 by the picker roller 6; some shorts are retained on it until they reach the shorts removal roller 7 which sweeps them down the outlet chute 9 through the vaned roller 11, which acts as an air lock, and into the air duct 10 along which they are blown to carry them through the pipe 12 and into the interior of the drum 4. Any long strands of tobacco that may still be on the main feed drum 4 are held in the carding of the drum and tend to be pushed more firmly into the carding by the action of the shorts removal roller 7, whereas the short strands are pushed between the pins of the carding on the drum 4 and, since they lie on the obtuse side of the pins on the removal roller 7, they then drop down into the outlet chute 9.

The tobacco at the bottom of the hopper 1 just above the roller 7, will contain a mixture of shorts and long strands, some of the shorts being derived from the breakdown of long strands by the refuser drum 5 as it removes excess tobacco from the main feed drum 4, which then work their way back through the tobacco, which in this area around in quite a complex manner, to the bottom of the hopper 1. Any long strands carried round by the removal roller 7 are caught by the carding on the drum 4 and carried away from the shorts removal area, whereas shorts tend to work their way round or get pushed round between the drum 4 and the roller 7. Some shorts, particularly the finer particles, may flow clockwise round the roller 7, against its rotation, and thence into the outlet chute 9.

Thus the combined effect of the carded main feed drum 4 and the carded shorts removal roller 7 is like a filter separating shorts from long strands.

As the shorts enter the main feed drum 4 from the pipe 12 they strike the deflector plate 18 and are scattered on the ribs 15 near the upstream end of the drum 4 (FIG. 2). The rotary motion of the drum 4 exerts a tumbling action on the shorts inside it and this, together with the obstructive effect of the ribs 15, causes them to be thoroughly mixed. The shorts slowly move along the drum 4 as the centrifugal force derived from its rotationpushes them along the outwardly sloping ribs 15 and as more shorts are fed into the drum, until eventually they are thrown out of the other end of the drum into the transfer chute 13 down which they fall to the vibrating tray 14 which scatters them more or less uniformly over a limited portion of the width of the conveyor 8. This portion is chosen, as is described and claimed in US. Pat application Ser. No. 622,875 (now abandoned) so that the shorts are contained in the main portion of the subsequently formed filler stream rather than in the outer portion which is trimmed off as such trimming of the shorts would further reduce their size and also produce substantial amounts of tobacco dust which cannot be incorporated in cigarettes. In addition this brings them nearer to a suction conveyor on which the filler is formed and this improves the performance of a density test device which controls the trimmer.

The modified construction of the carding drum shown in FIGS. 4 and 5 is provided in its interior with means to hinder the flow of shorts therethrough which, in addition to the ribs 15, comprises a pair of

frustoconical sieves

19 and 20 terminating in

unperforated lips

52, 53. The inner sieve 19 is coarser than the outer sieve 20 and their combined effect is to grade the shorts into three separate fractions of different-sized particles. These fractions are allowed to fall freely out of the drum and since the points from which they leave the drum are vertically aligned, the several flows strike one another and intermingle producing a well mixed stream. The fact that the particles have horizontal components of movement derived from the rotation of the drum 4 assists the mixing.

In the embodiment of FIGS. 6 to 8, in which similar parts bear similar references to those of the first embodiment, the shorts are tumbled in the interior of the refuser drum 5 and are fed into the main tobacco flow at the mouth of a chimney 3 up which the tobacco is conveyed pneumatically to be formed into the filler stream. In this arrangement the tobacco picked off the main feed drum 4 by the roller 6 is accelerated, by means of a projector roller 32, into a first winnowing chamber 21 at the mouth of the chimney 3 where the heavier, unwanted constituents of the tobacco are thrown off into a removal chamber 22, the main body of the tobacco being carried around a suction roller 23 into the chimmey 3. Suction is applied to the upper part of the chimney 3 and air vents 24 are provided to allow air flow through the winnowing chamber to assist in conveying the tobacco into the chimney 3.

The winnowed-out heavy tobacco particles are carried out of the chamber 22 by a corrugated roller 25 which pushes them under an air-sealing flap 26 into a secondary winnowing chamber 27 where any residual light tobacco particles which have been removed from the primary winnowing chamber 21 are blown up through a passage 28 to rejoin the main tobacco carpet at the mouth of the chimney 3, by means of air drawn up the passage 28 by the suction in the chimney 3.

In this embodiment as is shown in FIG. 7 the path which the shorts travel during tumbling is extended by introducing them into the refuser drum 5 through a secondary tumbling drum 29 which is formed internally in a similar way to the main feed drum 4 of the first embodiment, as is the refuser drum 5 itself in this embodiment, with a series of ribs which slope as the shorts advance, the direction of movement of the shorts being reversed as shown by the arrows in FIG. 7. The shorts are removed from the refuser drum 5, in the more uniform stream produced by its tumbling action, through a pipe 30, which is vibrated to help convey them through the pipe, to the removal chamber 22 (FIG. 8) where they mix with the heavy particles and are carried into the secondary winnowing chamber 27 where, being light particles, they are carried in the air stream passing therethrough up the passage 28 to join the tobacco carpet in the chimney 3. Referring to FIG. 8 it will be seen that the feed on to the corrugated roller 25 is arranged, by means of a shroud 31 and the position of the pipe 30 above the roller 25, so that the shorts are fed into the appropriate portion of the tobacco carpet.

Since the pressures in both the pipe 30 and the second winnowing chamber 22 are substantially atmospheric there is no need to provide an air valve in the shorts flow path which would be liable to cause interruptions in the shorts flow.

In the embodiment shown in FIGS. 9 to 11 the shorts are tumbled in the interior of the shorts removal roller 7 which is, like the carding drum 4 in the first embodiment and the refuser drum 5 in the second embodiment, formed internally with a series of sloping ribs 15. The shorts are fed into the removal roller 7 from the air duct 10 by means of a centrifugal separator 132 and a delivery pipe 33. They are removed through a perforated sleeve 34 which constitutes one end of the removal roller 7, and through which they fall into a vibrating tray conveyor 35. A fixed guard cover 36 is positioned under the sleeve 34 in the upper part of the roller 7 to prevent shorts falling through from the hopper 1 and thereby missing the effects of the tumbling in the removal roller 7.

The shorts are guided from the main feed roller 4 to the air duct 10 by a curved guide plate 37 and flexible seals 38 and 39 are provided to maintain the pressure difference between the hopper 1 and the air duct 10 (FIG. 11).

To assist in further smoothing the shorts flow the vibrating tray 35 is provided with a series of transverse ribs 40. The tray 35 feeds the shorts into a duct 41 through which an air current, generated by suction means in the upper part of the chimney 3, carries them to the air vents 24 and thence into the chimney 3. As before, they are fed into the chimney 3 towards one side thereof.

The perforations 54 near the extreme end of the sleeve 34 are somewhat larger than those in the remainder of the sleeve to allow any larger particles that accumulate to pass into the tray 35.

It will be seen from the above description that in each of the embodiments described, shorts are continuously removed from the tobacco supply, fed in a continuous flow, thoroughly mixed by a tumbling action in the interior of a rotating drum, so that the distribution of different-sized particles in the shorts flow is made more uniform, and finally incorporated in the tobacco fed to form the filler. In one embodiment the uniformity of distribution of different-sized particles is improved by sieving the shorts into different fractions each of one range of particle size, and then combining the fractions so that a more random distribution is achieved. The main purpose of these operations is to obtain the final tobacco filler a more regular, uniform distribution of the shorts; not only a more uniform quantity of shorts per unit length of the filler, but also a more uniform distribution of larger and smaller particles among the shorts.

What I claim as my invention and desire to secure by Letters Patent is:

1. Tobacco-feeding apparatus in a cigarette-making machine, comprising means to feed tobacco from a supply to provide a tobacco flow for the production of a tobacco filler, means to collect shorts from the supply, a hollow rotating drum, means to feed said shorts into and through the interior of said drum to be mixed by a tumbling action given to them by the rotation of the drum, and means to receive shorts from the drum after mixing and to feed said shorts for incorporation in the tobacco filler, the drum having an exterior surface which is capable of conveying tobacco in the tobacco-feeding apparatus.

2. Apparatus according to claim 1, wherein the drum is a feed drum whose exterior surface is carded and serves to feed tobacco from the supply.

3. Apparatus according to claim 1, further comprising a feed drum having an exterior carded surface for conveying tobacco from the supply and said hollow rtating drum is a refuser drum for leveling to tobacco on the surface of said feed drum.

4. Apparatus according to claim 1, wherein the drum is a drum located to receive shorts and on whose exterior surface the said shorts are received and carried away from the tobacco.

5. Apparatus according to claim 1, further comprising a feed drum having an exterior carded surface for conveying tobacco from the supply and said h'ollow rotating drum is a drum located adjacent said feed drum to receive shorts and on whose exterior surface the said shorts are received and carried away from the tobacco.

6. Apparatus according to claim 5, wherein said hollow rotating drum has an outlet at one end comprising a perforated cylinder at the said end through whose perforations the mixed shorts can fall.

Claims

3. Apparatus according to claim 1, further comprising a feed drum having an exterior carded surface for conveying tobacco from the supply and said hollow rotating drum is a refuser drum for leveling to tobacco on the surface of said feed drum.

5. Apparatus according to claim 1, further comprising a feed drum having an exterior carded surface for conveying tobacco from the supply and said hollow rotating drum is a drum located adjacent said feed drum to receive shorts and on whose exterior surface the said shorts are received and carried away from the tobacco.