GB1593248A - Cigarette manufacture - Google Patents

Description

(54) CIGARETTE MANUFACTURE (71) We, MOLINS LIMITED, a British Company, of 2, Evelyn Street, Deptford, London SE8 5DH, do hereby declare this invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention has as its main object the manufacture of cigarettes with the minimum of damage to the cut tobacco which is used to form the cigarette filler stream. Damage to the cut tobacco during the cigarette making process reduces "filling power" of the tobacco.

For any particular blend of tobacco there is mean length of strand with a spectrum of lengths about that mean which will confer the optimum filling power on the blend; that is, having regard to the chosen diameter of cigarette. For the purpose of this invention it is assumed that the leaf has been stemmed and otherwise prepared, cut, and winnowed so that after blending, cooling and loosening, the tobacco is in the desired state for filling cigarette rod.

According to one aspect of the invention, a cigarette making system comprises a duct arranged to feed tobacco pneumatically to a number of cigarette making machines and having a number of side outlets leading to the respective machines, each machine including a tobacco collator comprising substantially parallel bands which define a channel in which the tobacco passing out of the duct piles up and by which bands the tobacco is fed to a device for forming the tobacco into a cigarette filler stream.

Preferably the tobacco, on leaving the collator, is showered towards a suction tape on which it forms the cigarette filler stream. The means of showering the tobacco and of forming the tobacco filler stream may in accordance with the Molins Mark 8 or Mark 9 cigarette making machine or as described, for example, in British patent specification No. 929,338, which specification (together with the specifications mentioned therein) is referred to in its entirety.

Preferably, as in the above-mentioned specification, the tobacco shower is carried with the aid of an air flow towards the suction tape. Consequently it is possible to arrange that suction pressure exists at the end of the collator channel remote from the duct and assists the movement of tobacco into the channel from the duct.

In a preferred arrangement the combination of friction and air flow in the collator channel tends to produce a uniform pressurewise filling of the tobacco in each collator; furthermore, the manner of filling the collator with individual particles avoids felting and interlocking of the strands, ideal conditions for a uniform delivery of tobacco from the collators.

The collator bands are carried by rollers geared to the making machine drive so that the tobacco is fed from the collator at a rate appropriate for that of the suction band of the maker (cigarette making machine). The gear is chosen to provide the amount of cigarette tobacco required plus the discard necessary to the efficiency of the trimming device if such a device is used.

The bands may be air permeable if there is a tendency for them to close the gap under suction, and flexible seals may be necessary at the junction of the tobacco duct and the collator.

It may be advantageous to incorporate a smoothing brush B at the exit end of the collator as shown in Figure 2 and Figure 3, which latter figure also shows a collator adapted for hand feeding.

The collator may include blades for continuous cleaning of the rollers.

Emergency hand feeding can also be carried out through a door in the tobacco duct if the flow in the latter fails.

The action of the collator is a simple feed; the rollers free the strands of tobacco progressively because the strands are not interlocked and the tobacco is laid on the suction tape of the maker as a continuous narrowing of the width of the collator down to cigarette dimensions.

If the gear ratio is such that volume v of collator material provides the material for the filler for one cigarette then since volume v taken from anywhere has the same pressure, the cigarette filler will fill a given volume at a constant pressure.

As already mentioned, the action of formation of the cigarette filler stream may be similar to that of the Molins Cigarette Maker Mark 8. The collator is positioned so that the tobacco delivered from it is immediately in the air stream leading on to the suction tape. The collator frees the strands of tobacco progressively because the strands are not interlocked so the material is laid down uniformly on the suction tape.

The trimmer, if used, is set at a height from the tape necessary to produce cigarettes of the formula mean weight; the discard tobacco removed from the filler stream by the trimmer is preferably returned to the primary processing plant and recycled.

A number of machines are fed from the same tobacco duct, the disposition of the duct at the feed point being arranged to facilitate collection of tobacco from the air stream. An excess of tobacco is maintained in circulation so that all machines can be fed equally. The system involves negligible degradation of the tobacco. The tobacco in the collator is in noninterlocked disposition and so the particles are wafted into the maker trough (adjacent to the suction tape) without breakage. Similarly the trimmer is presented with a stream of tobacco which is layered parallel to the plane of the discs and the tobacco strands tend to be parted off without breakage; the discard may then be returned to the tobacco circulating system at any convenient point.

The absence of manipulative processes at the makers confers many benefits: Dust and shorts production is minimal and their separation need be provided for at only one point in the system.

The system can use the tobacco in moisture equilibrium with the ambient conditions whence: Moisture is eliminated as a principal factor in the system of weight or firmness control.

The tobacco moves with less friction, being dryer, and it is also less self adherent.

There is no need to clear the collators of tobacco at shut-down.

The rod as made is firmer; this assists the efficiency of the cut-off (which cuts the continuous cigarette rod into separate portions) and of the plug assembler (which joins filters to the cigarette portions, normally with a rolling operation).

The various aspects of this invention are illustrated in the accompanying drawings. In these drawings: Figure 1 shows a general layout of part of the apparatus including one cigarette making machine; Figure 2 shows one collator with side plates removed to show doctor blades D for the clearance of tobacco from the rollers; Figure 3 shows a modification of the collator for hand feeding of tobacco; Figures 4 to 9 show different arrangements and shapes of the duct in the region of a collator; Figures 4A to 9A are sections on the lines A-A in Figures 4 to 9 respectively; Figure 10 is a diagrammatic side view of part of a preferred tobacco cutter; Figure it is a diagrammatic end view from the left of the cutter shown in Figure 10, Figure 12 is a view, similar to Figure 10, of a different form of the cutter; and Figure 13 is a plan view of the cutter shown in Figure 12 with upper parts removed to show the tobacco leaves.

Brief descriptions of some of the components identified by reference numerals in the drawings are given at the end of this specification.

Tobacco Lengths The tobacco particles fed into the duct preferably have lengths lying as far as possible, between predetermined limits. This may be achieved by cutting the tobacco leaf in the manner described below with reference to Figures 10 to 13.

Ring Main Feed After the loosening, winnowing, blending and casing operations which may be required to reduce the tobacco to a state ready for cigarette making, the tobacco is fed into a ring main duct where it circulates. Control of the conditions in the duct is available by known means to regulate:- (a) the necessary air velocity in the duct to transport the tobacco, (b) the humidity and temperature conditions to suit the factory practice, and (c) the static pressure in the duct relative to the ambient which is a determining factor in the uniform filling of the collator.

Collator The tobacco circulating in the duct passes the entrance to each collator 100 into which it is sucked by the suction of the maker's suction fan, aided if necessary by a change of direction of the ring main duct at the collator, e.g. the bend 101 shown in Figure 1.

Control of the filling of the collator is effected if there is an adequate surplus of tobacco in circulation in the duct, i.e. if the tobacco supply is run some convenient time before the making machines start up; if the feed is adequately controlled the collators will always be substantially full.

The collator comprises parallel bands 102 and 103 defining a channel 104 communicating (Figure 2 only) directly with a side outlet 105 comprising an elongated aperture in the well of the duct 106. It should be noted that the planes of the bands are parallel to a plane containing the axis of the duct 106.

Collator Suction The other determining factor in the uniform filling of the collator is the negative pressure at the exit end of the collator; e.g. in the case of the Molins Mark 8 and similar machines this is determined by the negative pressure in the main suction chamber (above the suction tape) which communicates directly with the fan of the making machine.

Control of the pressure in the main suction chamber is obtainable by the use of the adjustable pressure regulator described in patent specification No. 1,294,310, which governs the flow of air to the chamber, and this maintains the desired constant pressure relative to the ambient.

Collator Filling. Uniform Compactness of tobacco Each collator channel 104 is of constant dimensions and fills with tobacco submitted to an air flow such that the pressure drop across the tobacco is constant. This air flow depends upon the level of the suction pressure existing in a chimney 107 leading to the suction tape 108 shown in Figure 2.

Control of the tobacco conditions in the collator is thus assured, and insofar as the tobacco is homogeneous the density of the collator filling is constant.

If however the elasticity of the tobacco varies locally the mass of tobacco per unit area will vary accordingly but, nevertheless, the distribution of the tobacco will be uniform pressurewise. This is because, in the conditions envisaged where an airflow acts as a compressive force on every strand, the forward thrust of the air is balanced by the friction of the tobacco on the walls of the collator and this is so on every elementary slice of tobacco across the stream, (except at the upstream entrance, but this does not affect the conditions at the delivery end).

The tobacco is compacted so that weak material is closed up and vice versa, equal slices added to a given volume contribute equal increments of pressure.

Feed to the Maker. Discard Control The tobacco feed rate is determined by the rate of rotation of the collator band rollers 109; for constancy of feed to the suction tape of tobacco, the rollers are geared to the main drive of the machine.

Control of the fraction of tobacco to be trimmed by the trimming device (not shown) is effected by adjustment of the gear ratio between the maker and the collator. This is normally held constant and is established empirically by weighing the discard. This control is maintained by the constancy of the conditions at the collator but a change of tobacco conditions necessitates a check on the discard. Known means (see for example patent specification Nos.

958,205; 958,206; 958,207) are available to measure the discard rate automatically and continuously; a visual indication may be given by the rate at which air is bypassed to the main suction chamber by the means referred to in the paragraph headed Collator Suction.

Transfer to Suction Tape The tobacco on emergence from the collator is transferred to the tobacco collator band of the making machine by high speed air flow up the chimney 102. The transfer distance is as short as practicable and the presentation of the material to the air is such as to avoid eddies in the air flow.

Control at this stage is aimed at obtaining a stream of tobacco on the suction tape which, under the condition of constant pressure drop, will be of uniform dimension.

This follows from the consideration that the tobacco in the collator is uniformly compacted in all directions, and that this carpet is fed at a uniform speed. The suction tape travels across the tobacco and thus an incremental layer of tobacco on the tape is derived from an incremental layer of tobacco in the collator carpet which is inclined at an angle to the direction of the carpet flow. But in the collator carpet the conditions are the same in all directions, so the tobacco is transferred to the tape uniformly volumewise and is presented to the trimmer at a constant level.

Compactness Conditions on the Suction Tape The tobacco on the suction tape is compacted by the airflow, progressively more compact the nearer the tape. The discard is removed by a trimmer leaving a quantity of tobacco per unit length which, if the tobacco is homogeneous and the pressure drop is constant across the tobacco at the trimming stage, will be of uniform weight per unit length.

If the tobacco is not homogeneous in its elastic characteristics, nucleonic control is known and available to maintain a mean weight, but the distance velocity lag and the high speed of making render difficult any significant improvement to the uniformity of weight per unit length inside cigarettes.

However with the means described herein it is possible to produce cigarettes which are uniformly filled pressurewise even with non-homogeneous tobacco and this is a very desirable characterstic.

Control at this stage consists in maintaining a constant pressure drop across the tobacco on the tape and this results from the maintenance of the main suction chamber pressure constant which has been described in paragraph headed Collator Suction.

Tobacco Compression from Trough Dimensions to Cigarette Dimensions The uniformity of the tobacco distribution pressurewise in the collator and on transfer to the tape, together with the constancy of the pressure drop across the stream on the tape result in a distribution of tobacco in the stream which after trimming at a given level will fill a given cross-section to a constant pressure.

However the formation of the cigarette rod involves reducing the cross-section of the web by a third or so, and insofar as the tobacco has local variations in spring rate, this compression would result in a small disturbance in the distribution.

Control here is automatic because the dimensional changes are small and hence the localities where the volume reduction would result in a relative increase in pressure over neighboruing localities are able to relieve that pressure by expanding into the low pressure regions. Here it is necessary to remark that the velocity of pressure transmission in tobacco in this form is quite high enough for this pressure adjustment to take place.

The adjustment towards equality of pressure is assisted if during the transfer from the suction tape to the rod-forming or "garniture" tape (not shown) the stream of tobacco is released from constraint and allowed to expand; the tobacco thereby has the facility to make the small displacements tending to uniformity of pressures at the expansion stage as well as at the compression stage.

Of course if the tobacco is non-homogeneous the tendency will be to accentuate weight per unit length variations, while maintaining uniform filling pressure.

Rod Forming A further stage occurs when the rod has been formed but the heater has not been reached.

To admit the gum line to contact with the heater, the rod is released from circumferential constraint. The pressure of the tobacco tends to expand the rod by shearing the gum line and this gives a final opportunity for high pressure localities to ease the excess.

If the controls as described are accurately maintained it is possible to omit the trimming operation and this may have a particular value for lightly filled, small cigarettes.

Without trimming, control to a formula mean weight is by varying the gear ratio between collator and maker (see section headed Feed to the Maker. Discard Control). This may be governed by nucleonic measurements or bulk gravity weighings.

In the sum the invention provides means whereby cigarettes can be filled without trimming to a uniform internal pressure: the weights of such individual cigarettes are dependent on the elastic characteristics of the tobacco, but as the tobacco is used to the best filling advantage the result is uniformity of filling with economy in tobacco.

Pressure Conditions in the Collator The passage of the air through the collator exerts a forward thrust on the tobacco which is thereby put under pressure. This pressure on the containing walls (the bands) engenders friction which opposes the forward thrust. The pressure is communicated forward and rises until the friction equals the thrust, the tobacco then remains captive in that state of pressure.

In broad terms the thrust due to a given airflow on a mass of tobacco is proportional to that mass, and the limiting condition for the pressure is Thrust =1 Friction Thrust Mass Density x Volume But a ----- a Friction Friction Coeff.Friction (u) x Pressure x area So at the limit of compacting 1 Density Pressure But the density of a particular tobacco is related to the pressure in a known manner and K is a constant parameter given the speed of the air flow, dimensions of the collator and the coefficient of friction.

Therefore, the equation Pressure = K Density has a unique solution for the pressure, say Po. The airflow through the collator is the same across any cross section if, additionally, as has been indicated above, it is maintained substantially constant with time, when Po has the same value everywhere in the collator, no one location having any different conditions from any other and no variation with time.

The arrangement is such that if a cigarette manufacturer is interested in controlling the weights of individual cigarettes rather than in the uniformity of filling pressure, advantage is likely to be found in retaining the trimmer pressure the trimmer and its controls can be dispensed with.

Figures 4 to 9 with their respective sectional views 4A to 9A show different arrangements and shapes of the duct (identified in each example as 110) in the region of a collator 111.

Explanation The following additional explanation of this invention may be helpful: 1. The invention describes a simpler mechanical construction than the known art but in addition it offers economy in the use of tobacco tending, as it does, to the filling of cigarettes to a uniform pressure at all points along their lengths, using tobacco of dimensions giving the optimum filling value.

2. The same construction provides improved means of applying the known nucleonic thickness measurement control, if preferred, in that the distance velocity lag associated with measurement on the formed rod can be eliminated.

3. The advantage described in para 1 above derives from the pressurewise constancy of filling of the collator; which obtains because of the constancy of the static pressure drop in the air stream through the collator.

In the system envisaged the static pressure at the input to the collator derives from a fan of overmatching capacity feeding a ring pneumatic main serving a number of collators. Since the pressure loss in the ring main is very small overall and is constant at each collator station, differences are corrected for by calibration correction to the collator feed at each station, and so can be neglected in this argument.

Since the collators vent to the atmosphere the pressure drop through all collators in the same whatever the state of filling of the collators may be, however it is envisaged that the tobacco feed will be arranged to overmatch the demand at all collators which will be maintained full. The point is that the pressure drop across the collator will remain constant should it temporarily cease to be full; the resistance to the air flow will drop, the flow increases increasing the total air drag to equality with that of a full collator.

Since the air supply is connected to a number of collators the input pressure will be affected by the flow demand overall and thus variations in demand by individual collators arising from failure to fill will be effectively averaged out. By choice of fan the variations can be made small in any case.

4. The pressure drop is therefore the same across all collators.

This pressure drop is occasioned by the impact of air on the tobacco particles and is measured by the reaction forces on the particles in opposing downstream movement.

Since the arrangements are such that the feed of particles to the collator is by individual particles, they will be advanced by an airstream parallel to the collator walls until arrested by the mass onto which they are pressed by the air flow and, necessarily for equilibrium, stressed to the same degree as the stationary mass. Friction action by the side walls therefore plays no part at the deposition stage, it only tends to hold the tobacco in place if the air flow is cut off.

For equilibrium therefore the stress must be the same at all levels in the collator and this must equal the static pressure drop in the airstream across the collator.

This state of uniform pressure throughout the collator holds whatever may be the shape, thickness of density of the particles concerned, which property of the collator is of great advantage for tobacco which has great diversity in all these parameters.

5. The system design requires a knowledge of the packing density of the tobacco in the collator corresponding to the pressure drop and this entails an investigation of the elastic properties of tobaccos.

To be applicable to the system, static measurements of the elasticity must be made under conditions which eliminate friction effects. Cylinder and weighted plunger methods are not appropriate; only methods employing hydraulic pressures are suitable.

A sample of tobacco consists in a whole spectrum of lengths of shred with irregularities of great variety; their ability to resist deformation is very diverse. So, under pressure, the weaker elements collapse progressively into a state of greater density of packing and a stronger resistance to compression.

So equal increments of pressure produce less deformation as the pressure rises.

Assuming that this volume diminution dv. is proportional to the pressure P.

;Ipdv = where b is a constant.

Considering unit mass, v is the specific volume and the relation between pressure and specific volume is then: v = a-blogp.

Figure 1 displays, in graphical form, the results of two experiments among many which confirm the relationship. For convenience p is in inches Mercury Gauge logs to base 10 v, a, and bare specific volume c.c./gm 6. Since the fan supplying the collators with air also has to transport the tobacco and the type of fan most suitable is paddle bladed, materials handling which is commerically available.

It also has a great advantage that it can supply up to 60% of its rated flow delivery without material change of static pressure.

7. At the stream velocities envisaged the drag force of the air F on a particle is proportional to the square of that velocity V, and the air behaves as if it were incompressible.

Therefore F = cV2 where c is a constant.

In free fall a particle acquires a terminal velocity Vo where the air drag equals the force of gravity on the mass M of the particle.

i.e. Mg = cVo2 V2 Therefore F = Mg Vo2 Although individual particles have somewhat varying terminal velocities the variation is not great with tobacco because the lamina are generally similar except in length and this results in a drag force proportional to the mass of the particle.

For an estimation of V in a collator we are concerned only with the total drag force and thus in the equation we can use the mean value of VO appropriate to a random sample of the tobacco concerned which is approximately 150 cm/sec.

The pressure p on the tobacco in a collator of cross sectional area A, filled to a depth X, is thus F Mg V2 p =-=-x- A A Vo2 = Mgx V2 - gxV2 Ax Vo2 v Vo2 But from para 5, specific volume v is given by v = a-blogp.

Therefore V2 = p(a-b log p) Vo2 g If X is the full length of the collator the minimum volume rate demand for n collators is nVA which can be found since all the variables are known.

Q for collators = nAVO p(a-b logp) cc/ sec g = nAVO pv cfm.

296 x Conveniently allowance can be made for losses of flow in the system by adjustment for Q.

For pressure losses in the duct system due to wall friction, losses at bends and joints, and drag on the stationary tobacco intruding into the duct, allowance should be made by an increment to the design value ofp in this equation.

If the same fan is to be called on to introduce the tobacco into the duct the acceleration of the tobacco would involve a pressure loss which would also need to be added top.

8. For efficiency in transporting the loose tobacco in the duct the stream velocity therein needs to be at least 5 metres per second, so Total Fan Delivery = Q = 500 r2 where r is the radius of the duct This relation gives a limit to the size of the duct which must not be exceeded.

The restraining friction force at the walls must be sufficient to prevent the tobacco from being blown out of the collator en masse.

Owing to the ability of tobacco to withstand a shear force the forward pressure p is only communicated in part laterally. The lateral pressure is p and if u is the coefficient of friction, the frictional reaction isu times the lateral thrust.

For a collator of width I depth t length x the requirement is Friction reaction Forward thrust 2(1 + t)p u ltp.

Therefore lt butt is small 2 u(l + t) relative to l.

Therefore t n.b.u. = .36 2u = 04) .04 approx.

This relation imposes a limit on the degree of emptiness permitted in the collator. A lamp and photocell would provide the signal for a warning or control of this feature.

9. The introduction of the tobacco into the duct involves acceleration of the mass of say m gm per second. The air must supply a force accordingly equal to the rate of change of momentum i.e. to mass rate times velocity, mV.

The corresponding pressure drop is mV A1 In CG.S units mV gm/cm2.

gAl and p = mV inches W.G.

2.5HgA1 The area A, is that of the duct into which the tobacco is introduced, e.g. that of the materials handling fan employed to provide the airflow.

10.

DA TA (by way ofexample) Weight of cigarette = 1 gm Mass flow of tobacco through Rate of making 3600 cpm. the collator = 60 gm/sec.

= 60 per sec.

Selected fan working pressure = 6 inch W.G.

( = .44 inch Hg p( = 15.22 gm/cm .22 gdyne/cm2 Collator Width 61 cm A = 55 sq. cm.

Depth .9 cm Length x cm Desired No. of machines n = 20 Elasticity of chosen tobacco a = 4.84) forpininch v =4.84-1.8log.44 b = 1.8 ) Hg = 5.48 cc/cm.

Volume rate of delivery of tobacco from collator = 60 x 5.48 = 328.8 cc/sec.

Linear feed rate of collator = 328.8 = 6cm/sec.

55 V2 = pV Vo2 g VO = 150cm/sec. 15.22x5.48 x = 25cm V = 150 =274 x 25 cm/sec Q = nVA Air flow through collator = AV = 55x274 = 15070 cc/sec.

Air flow for 20 machines = Q.

= 301400 cc/sec.

Diameter of ring main = .301400 x 35.315 x 60 duct = 638 CFM Q = 7r r2500 cc/sec. d > 2 r = 27.7 cm = 10.9inches.

Ap = mV IfA1is3" diam. Ap = .26 inch 2.54gA1 W.G.

11. If the system is to be used with a Beta ray weight control a source across the collator can be made to scan the tobacco which will go to form the cigarette by inclining it at an angle whose tangent is the rates of the collator forward velocity to that of the collecting band of the cigarette maker. It is of the order 1 ".

Figures 10 to 13 are examples of preferred arrangements for cutting tobacco leaf to produce tobacco particles with lengths lying substantially with a predetermined range so as in particular to avoid the production of excessively long particles.

In these cutting systems tobacco leaves which have been stemmed are laid approximately uniformly in a smooth trough of which the floor is formed by an air permeable band driven at the same speed as the feed rate of the cutter.

The leaves are carried by the band without disturbance and pass over a perforated suction box, air flow through which flattens and presses the leaves together. The leaves pass under a band, inclined and driven so as to compress the leaves into a compact mass. Alternatively and more simply, the compression may be effected by a flexible strip across the width of the trough drawn down by the suction, thus squeezing the material between the strip and the suction box.

The tobacco so compressed is slit into sections of the required width and the streams of tobacco thus formed are fed directly to the tobacco cutter (which may be of any conventional construction) which cuts the leaves transversely to the slits at closely spaced intervals.

A construction functioning in this manner is illustrated in Figure 10.

A trough 1 of the width related to the width of the tobacco cutter trough has at the inlet end an endless air permeable band 2 running in its bed in the forward direction. The trough is air permeable at one section 3 and under it is a box 4 communicating with the suction side of a fan 5 (Figure 11). Located in the trough and above the suction box 4 is an endless full-width air permeable band 6 inclined downwards and driven so that its underside advances forward.

Inside the band a box 7 similar to box 4 communicates with the pressure delivery side of fan 5 and may be positioned and shaped so as to reinforce the air flow and improve its effectiveness on the tobacco leaves.

In the trough 1, as close as convenient to band 6, a set of evenly and adjustably spaced slitters 8, are driven, as shown in Figure 12. They are located a little downstream of a driving roller 9 drum of band 2 and run in grooves or slits in the bed. Means (not shown) may be provided for automatically and/ or continuously sharpening the slitters.

The floor of trough 1 is smooth, and material after slitting is pushed on by the following material, or it can if necessary be forwarded by a conveyor band to the receptor at the cutter, now shown.

For full efficiency leaves 10 which have been stemmed are opened out and laid as flat as possible, oriented relative to the trough in the direction found to be the optimum (experience indicates lengthwise). The leaf pile is continuously drawn by band 2 to the airflow region where it is compacted vertically.

The pile of leaf is compressed further by the pressure between bands 6 and 2 and the nip between them provides reaction to the thrust of the slitters 8.

The compacted slit material is advanced in the trough by the pressure of the following material and is directed so as to come into the nip of the cutter drive mechanism (not shown).

If this distance is short, the adhesion of tobacco leaves is sufficient to hold the material and no restraining means to maintain the conformation will be necessary: otherwise, a conveyor band similar to band 2 assembly would meet the case.

The feed rate of the slitter is regulated to conform to the forward speed of the material in the cutter.

In place of the band 6 in Figure 10, a flexible leaf compressor 11 of impermeable fabric or thin strip steel may be used, as shown in Figure 12.

The construction is conceived as an adjunct to an existing tobacco cutter but they may be integrated if it be advantageous.

In Figures 1, 2, 3, and 11, some components are identified by reference numerals not mentioned above. Brief descriptions of those components are as follows: Figure 1 200 Primary area of the system.

201 Apparatus by which the tobacco is stemmed, winnowed and cased.

202 Apparatus by which the tobacco is mixed, aired, loosened, has dust extracted, is dried and cooled.

203 Tobacco Duct.

204 An Emergency hand feed.

205 A motor.

206 Gearbox.

207 Roller band collator.

208 Perforated band.

209 Main suction chamber.

210 Trimmer.

211 Receives the discard tobacco (i.e. that removed by the trimmer).

212 Other parts of the maker.

213 Fan.

214 Tobacco duct return.

Figure 2 215 Main suction chamber.

Figure 3 216 Hand feed table.

Figure 11 217 Motor.

218 Fan.

WHAT WE CLAIM IS: 1. A cigarette making system comprising a duct arranged to feed tobacco pneumatically to a number of cigarette making machines and having a number of side outlets leading to the respective machines, each machine including a tobacco collator comprising substantially parallel bands which define a channel in which the tobacco passing out of the duct piles up and by which bands the tobacco is fed to a device for forming the tobacco into a cigarette filler stream.

2. A cigarette making system as claimed in claim 1, so arranged that the tobacco, on leaving the collator, is showered towards a suction tape on which it forms the cigarette filler stream.

3. A cigarette making system as claimed in claim 2 in which the tobacco shower is carried with the aid of an air flow towards the suction tape.

4. A cigarette making system as claimed in claim 3 in which suction pressure exits at the end of the collator channel remote from the duct and assists the movement of tobacco into the channel from the duct.

5. A cigarette making system as claimed in claim 4 in which the collator bands are air permeable.

6. A ciagarette making system as claimed in any one of claims 2 to 5 including a rotary brush at the exit end of each collator channel to assist the movement of the tobacco.

7. A cigarette making system as claimed in any one of claims 1 to 6 in which the duct forms a closed loop so that any tobacco which is not received by one of the machines can recirculate in the duct.

8. A cigarette making system as claimed in any one of claims 1 to 7 in which the duct has a bend adjacent to each machine whereby the impetus of the tobacco helps to carry the tobacco into the collator channel.

9. A cigarette making system as claimed in any one of claims 1 to 8 in which the collator bands are approximately parallel to a plane containing a central axis of the duct.

10. A cigarette making system as claimed in any one of claims 2 to 9 in which the suction tape, in the region where it receives the tobacco shower, runs in a direction transverse to the direction of movement of the collator bands, so that each portion of the cigarette filler stream contains tobacco which is received from various positions across the collator channel.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (15)

1. **WARNING** start of CLMS field may overlap end of DESC **.

   Figure 1

   200 Primary area of the system.

   201 Apparatus by which the tobacco is stemmed, winnowed and cased.

   202 Apparatus by which the tobacco is mixed, aired, loosened, has dust extracted, is dried and cooled.

   203 Tobacco Duct.

   204 An Emergency hand feed.

   205 A motor.

   206 Gearbox.

   207 Roller band collator.

   208 Perforated band.

   209 Main suction chamber.

   210 Trimmer.

   211 Receives the discard tobacco (i.e. that removed by the trimmer).

   212 Other parts of the maker.

   213 Fan.

   214 Tobacco duct return.

   Figure 2

   215 Main suction chamber.

   Figure 3

   216 Hand feed table.

   Figure 11

   217 Motor.

   218 Fan.

   WHAT WE CLAIM IS: 1. A cigarette making system comprising a duct arranged to feed tobacco pneumatically to a number of cigarette making machines and having a number of side outlets leading to the respective machines, each machine including a tobacco collator comprising substantially parallel bands which define a channel in which the tobacco passing out of the duct piles up and by which bands the tobacco is fed to a device for forming the tobacco into a cigarette filler stream.
2. 2. A cigarette making system as claimed in claim 1, so arranged that the tobacco, on leaving the collator, is showered towards a suction tape on which it forms the cigarette filler stream.
3. 3. A cigarette making system as claimed in claim 2 in which the tobacco shower is carried with the aid of an air flow towards the suction tape.
4. 4. A cigarette making system as claimed in claim 3 in which suction pressure exits at the end of the collator channel remote from the duct and assists the movement of tobacco into the channel from the duct.
5. 5. A cigarette making system as claimed in claim 4 in which the collator bands are air permeable.
6. 6. A ciagarette making system as claimed in any one of claims 2 to 5 including a rotary brush at the exit end of each collator channel to assist the movement of the tobacco.
7. 7. A cigarette making system as claimed in any one of claims 1 to 6 in which the duct forms a closed loop so that any tobacco which is not received by one of the machines can recirculate in the duct.
8. 8. A cigarette making system as claimed in any one of claims 1 to 7 in which the duct has a bend adjacent to each machine whereby the impetus of the tobacco helps to carry the tobacco into the collator channel.
9. 9. A cigarette making system as claimed in any one of claims 1 to 8 in which the collator bands are approximately parallel to a plane containing a central axis of the duct.
10. 10. A cigarette making system as claimed in any one of claims 2 to 9 in which the suction tape, in the region where it receives the tobacco shower, runs in a direction transverse to the direction of movement of the collator bands, so that each portion of the cigarette filler stream contains tobacco which is received from various positions across the collator channel.
11. 11. A ciagarette making machine including a collator and a device for forming a cigarette

    filler stream as defined in any one of claims 1 to 10.
12. 12. A method of making cigarettes in which tobacco is fed pneumatically to a number of cigarette making machines by a duct having side outlets leading to the respective machines, each machine including a tobacco collator comprising substantially parallel bands which define a channel in which the tobacco passing out of the duct piles up and by which bands that tobacco is fed to a device for forming the tobacco into a cigarette filler stream.
13. 13. A system according to claim 1 and substantially in accordance with any one of the examples described with reference to the accompanying drawings.
14. 14. A machine according to claim 11 and substantially in accordance with any one of the examples described with reference to the accompanying drawings.
15. 15. A method according to claim 12 and substantially in accordance with any one of the examples described with reference to the accompanying drawings.