US3716062A

US3716062A - Cigarette-making machines of the continuous-rod type

Info

Publication number: US3716062A
Application number: US00081567A
Authority: US
Inventors: D Molins; R Ahern; F Labbe
Original assignee: Molins Ltd
Current assignee: Mpac Group PLC
Priority date: 1964-04-13
Filing date: 1970-10-16
Publication date: 1973-02-13
Anticipated expiration: 1990-02-13
Also published as: DE1298028B; CH442111A; NL6504712A; SE327660B; BE662437A; GB1109184A; DE6606440U

Abstract

BETWEEN THE TRAILING END PORTION OF THE PLATE AND THE PERIPHERY THEREOF AND ADVANCES THE SAME INTO THE AIR STREAM AT THE INLET OF THE DUCT AT AN OBLIQUE ANGLE THERETO. BOTH THE PICKER WHEEL AND THE PROJECTING ROLLER ARE COVERED BY A SECOND PLATE LOCATED OPPOSITE THE CURVED PLATE, THEREBY FORMING A CHAMBER ENCLOSING THE SAME.

A CONTINUOUS-ROD CIGARETTE-MAKING MACHINE OF THE TYPE IN WHICH TOBACCO IS CARRIED BY AN AIR STREAM TO A SUCTION CONVEYOR ON WHICH THE TOBACCO FILLER IS FORMED. THE AIR STREAM IS DIRECTED OBLIQUELY FROM ONE SIDE INTO THE INLET OF A DUCT LEADING TO THE CONVEYOR SO THAT THE AIR STREAM CHANGES DIRECTION AS IT ENTERS THE DUCT RESULTING IN A VELOCITY GRADIENT ACROSS THE WIDTH OF THE AIR STREAM AS IT CHANGES DIRECTION. A STREAM OF TOBACCO IS PROJECTED OBLIQUELY INTO THE INLET AND THE AIR STREAM FROM THE OPPOSITE SIDE THEREOF SO THAT THE TOBACCO PARTICLES ARE FIRST SUBJECTED TO THE SIDE OF THE AIR STREAM HAVING THE GREATEST VELOCITY RESULTING IN IMPROVED DISPERSION OF THE TOBACCO PARTICLES IN THE AIR STREAM. THE TOBACCO STREAM IS FED INTO THE AIR STREAM FROM A HOPPER HAVING A CARDED DRUM AND A REFUSER ROLL ADJACENT THERETO, AND A PICKET WHEEL TO REMOVE TOBACCO FROM THE CARDED DRUM. THE PICKER IS PLACED ADJACENT TO A CURVED PLATE AND IS ARRANGED TO ADVANCE THE TOBACCO TO A PROJECTING ROLLER WHICH GRIPS THE TOBACCO

Description

Feb. 13, 1973 D. w. MOLINS ETAL 3,7L6;062

CIGARI'TF'I'Y'P-MAKING MACHINES OF THE CONTINUOUS-ROD TYPE Original Filed April 12, 1965 2 Sheets-Sheet 1 INVENTO R5 DMJWMS, 115mg. +2114 Luau Warsaw, 001.5. Ghana '0 Umou ATTORNEYS Feb. 13, 1973 MQLINS ETAL 3,7165062 CIGARETTE-MAKING MACHINES OF THE CONTINUOUS-ROD TYPE Original Filed April 12, 1965 2 Sheets-Sheet 2 QQQ l 54 a IIIIIIIII'IJJIIIIIIIIIIIIIIIIIIIIIIIIIIIII 1 11/ I I [1 1 I I I I in. means, RA. Pmum '1- EM L RBI-E United States Patent 3,716,062 CIGARETTE-MAKING MACHINES OF THE CONTINUOUS-ROD TYPE Desmond Walter Molins and Ronald Albert Ahern, London, England, and Francis Auguste Maurice Labbe, Neuilly-sur-Seine, France, assignors to Molins Limited, London, England Continuation of application Ser. No. 770,905, Oct. 23, 1968, which is a continuation of application Ser. No. 447,368, Apr. 12, 1965, both now abandoned. This application Oct. 16, 1970, Ser. No. 81,567

Int. Cl. A24c 5/39 US. Cl. 131110 32 Claims ABSTRACT OF THE DISCLOSURE A continuous-rod cigarette-making machine of the type in which tobacco is carried by an air stream to a suction conveyor on which the tobacco filler is formed. The air stream is directed obliquely from one side into the inlet of a duct leading to the conveyor so that the air stream changes direction as it enters the duct resulting in a velocity gradient across the width of the air stream as it changes direction. A stream of tobacco is projected obliquely into the inlet and the air stream from the opposite side thereof so that the tobacco particles are first subjected to the side of the air stream having the greatest velocity resulting in improved dispersion of the tobacco particles in the air stream. The tobacco stream is fed into the air stream from a hopper having a carded drum and a refuser roll adjacent thereto, and a picker wheel to remove tobacco from the carded drum. The picker is placed adjacent to a curved plate and is arranged to advance the tobacco to a projecting roller which grips the tobacco between the trailing end portion of the plate and the periphery thereof and advances the same into the air stream at the inlet of the duct at an oblique angle thereto. Both the picker wheel and the projecting roller are covered by a second plate located opposite the curved plate, thereby forming a chamber enclosing the same.

This application is a continuation of our copending application Ser. No. 770,905, filed Oct. 23, 1968 (now abandoned) which in turn is a continuation of our copending application Ser. No. 447,368, filed Apr. 12, 1965 (now abandoned).

This invention relates to continuous-rod cigarette-making machines, and more particularly to such machines of the type in which a continuous tobacco filler is formed on a face of an air-pervious face, being held to face suction applied through the conveyor.

In machines of the type above defined, as indeed in the long established shower type of machine, in which tobacco is allowed to fall in a shower on to an impervious conveyor, it is of the utmost importantce to secure maximum uniformity in the deposition of the tobacco on the conveyor. With this requirement in view, it has been found advantageous to arrange a duct with its outlet adjacent to the air-pervious conveyor, so that suction applied through the conveyor creates an air-stream through said duct, and then delivers the tobacco to the inlet of the duct so that it is entrained by the air-stream. Such a machine is disclosed in U.S. Pat. No. 3,030,965 but while machines of the form described in detail in said patent have been found quite successful in commercial use, they have proved somewhat expensive to construct.

It is an object of the present invention to provide a continuous-rod cigarette-making machine of the type above defined, but permitting a somewhat simpler and hence less expensive construction.

According to the invention, we provide a continuousrod cigarette-making machine having an air-pervious conveyor, means for applying suction to one face of the conveyor, a tobacco duct having an outlet in communication with the other face of the conveyor and an inlet spaced from said conveyor, and feed means for directing a stream of tobacco particles into said inlet so as to be entrained in a stream of air entering said duct for transport to said conveyor, in which said feed means is so arranged relative to said duct and to an air-guide member associated with said inlet that the tobacco stream enters said inlet obliquely from one side while the air-stream enters said inlet obliquely from the other side, the tobacco stream meeting the air-stream substantially transversely in a region where the air-stream is changing direction ,so as to promote dispersion of the tobacco particles.

With such an arrangement, the air-stream is constrained to change direction as it enters the inlet of the duct, and, therefore, the air velocity will be different at different positions across the width of the inlet; in general, near the side from which the air enters the velocity will tend to be low. The tobacco particles, entering from the other side of the inlet, will be entrained by the air-stream but the heavier particles will be least deflected and will reach the far side of the inlet without acquiring any substantial speed in the direction of the air stream. For the heaviest particles, e.g. pieces of tobacco stem, this 'will mean that they reach the far wall of the inlet, in the region of lowest air velocity, and will not be entrained by the air stream, and such heaviest particles can very conveniently be caused to separate from the remainder of the tobacco particles by arranging that the duct is vertical, with the inlet at its lower end; pieces of stem and other heavy particles then fall after reaching the far side of the inlet and can be collected and removed at a level below said inlet.

We prefer to produce the air stream by applying suction to the outlet of the duct and in some circumstances a sufficient air stream may be produced by the suction means associated with the conveyor. Usually however it is desirable to have a greater flow of air at the inlet than can be achieved in this manner, and preferably we provide further suction means connected to one or more openings in the walls of the duct adjacent to the outlet thereof. Such further suction means, sometimes termed a supercharger, is particularly desirable (and usually essential) when the duct is vertical, with the inlet at its lower end, as there must then be a sufficient air velocity in the duct to support the weight of the tobacco particles, i.e. the air must rise in the duct at a velocity greater than the terminal velocity of the particles when allowed to fall under gravity. The one or more Openings being provided adjacent to the outlet of the duct, it can be arranged that the velocity of the particles is sufliciently high for them to reach the conveyor after passing said one or more openings, even although the air velocity alone may not be sufiicient to maintain the particles entrained in the air stream once said one or more openings have been passed.

The duct may be of various forms but we prefer that the inlet be of larger cross-sectional area than the outlet; in a preferred arrangement the duct is of generally rectangular section throughout its length, the smaller dimension of the rectangle decreasing from the inlet to a point approximately halfway along its length and the "cross-section thereafter being constant to a point adjacent the outlet, and the aforementioned smaller dimension again increasing to a maximum and then again decreasing until, at the outlet, said smaller dimension is approximately equal to thewidth of the conveyor. The configuration of the portion of the duct adjacent to the outlet, i.e. adjoining the conveyor, may be as set out in Us. Pat. No. 3,088,468 issued May 7, 1963.

The air-guide member associated with the inlet is preferably in the form of a further duct, also of rectangular cross-section. We also prefer that the cross-section of said further duct be substatnially uniform along its length and approximately equal to the cross-section of the inlet of the tobacco duct. Preferably, such further duct has restrictor means for adjustably restricting its cross-section at or adjacent to its outlet to permit a desired air velocity to be obtained at the inlet of the tobacco duct. Such restrictor means may be a pivotally mounted plate with a screw adjuster for setting said plate at a desired inclination. The inlet end of said further duct-i.e. the end remote from the inlet of the tobacco ductmay be flared. Where as is preferred the tobacco duct is substantially vertical, with its inlet at its lower end, to promote separation of the heavier tobacco particles as previously set out, the further duct may be at an acute angle to the vertical and have its inlet end so flared as to provide a downward-facing portion through which separated heavy particles may fall into a receiver and a horizontally-facing portion through which air may enter. A gap is preferably left between the adjoining ends of the tobacco duct and the further duct, substantially opposite the tobacco feed means, through which gap air may enter to assist in producing desired patterns of air flow in the region of the inlet of the tobacco duct i.e. where the air stream and the stream of tobacco particles meet.

In order that the invention may be well understood, a preferred embodiment thereof will now be described in more detail, referring to the accompanying drawing in which:

FIG. 1 shows, in section and somewhat diagrammatically, the relevant parts of one form of continuousrod cigarette-making machine embodying the invention; the view shown is from one end of the machine, the front of the machine being shown to the left;

FIG. 2 is a similar view of a slightly modified form of machine; and

FIG. 3 is a fragmentary view partly in section taken along the line III-III of FIG. 1.

Referring first to FIG. 1, the machine is viewed endwise, i.e. in such manner that the cigarette rod when formed will be travelling at right-angles to the plane of the drawing. The part of the machine which is shown is that part, usually termed the hopper, which produces, from a bulk supply of tobacco, a substantially uniform stream of tobacco on a moving conveyor belt, said stream constituting a tobacco filler substantially ready for compression into a tobacco rod which may be wrapped to form a cigarette rod from which lengths may then be cut at regular intervals to provide individual cigarettes.

Turning to the drawing, an outer hopper casing 1 (only part of which is shown) provides accommodation for a supply of tobacco in the region 2 and thereabove. The bulk tobacco in part rests against two

drums

3, 4, which are mounted close to one another on shafts 5, 6, respectively so that their cardings almost touch and said shafts are both driven in the same direction (anticlockwise as seen in the drawing). The upper, and smaller, drum 3 is provided with a cleaner 7 also driven anticlockwise so as to prevent tobacco being carried round by the carding of drum 3 past a screening plate 8, said drum 3 serving to remove excess tobacco from the nearest part of drum 4 and return such excess to the main tobacco-containing region 2. The drum 4 carries tobacco in its carding past drum 3, which moves in opposition to drum 4 at the region where the two drums most closely adjoin one another, to a picker drum 9; as the carding of drum 3 removes excess tobacco from the carding of drum 4 the latter delivers tobacco to the picker drum 9 as a fairly uniform fleece or carpet. The majority of the tobacco carried by drum 4 is removed by the picker drum 9, but short particleshereafter merely termed shorts" as is conventional-remain in the, carding of drum 4 and are carried past a masking plate 10 to a shorts recirculation device 11 which is fully described in Molins et al. US. application Ser. No. 388,212, filed Aug. 7, 1964, now abandoned. Shorts also reach the device 11 from the right via a gap 31 between drum 4 and casing 1. A straight downward extension 41 of the casing 1 together with a similar downward extension 42 of masking plate 10, forms a chute which leads into a funnel-shaped sheet metal member 43. Below the funnel 43 is the recirculation device 11 which comprises a block 44 which has a vertical passage 45. The center portion of this passage is shaped to receive in a substantially air-sealing manner a rotatable non-return valve 46 which has two pockets 47 extending longitudinally of itself. Below the valve 46 is a manifold 48 which is open to the valve at its top. A pipe 49 extends upwards from the end of the manifold 48 and has also a horizontal portion 50 which terminates in a nozzle 51 which is adjacent the drum 4. All shorts recirculated by the device 11 are returned to the region 2 in such a manner that they are largely caught up in a rotating mass of tobacco formed against the

drums

3, 4 as indicated by the dashed circle 32. This has been found to achieve a worthwhile measure of uniformity in the distribution of shorts in the cigarettes ultimately produced and hence has a favorable influence on the uniformity of weight of individual cigarettes.

The picker drum 9 is carried on a shaft 12 which rotates clockwise and feeds the tobacco taken from the drum 4 to a winnower drum 13, carried by a shaft 14 which also rotates clockwise. Aroundpart of the circumference of the winnower drum 13 is a concavelyformed plate 15 having minimum working clearance from the outermost parts of the winnower drum so that the tobacco fed to said winnower drum is firmly gripped between the drum 13- and plate 15 and is thrown out, in a direction determined by the configuration of plate 15, into the inlet 16 of a tobacco duct 17. Said duct has a lower portion 18 of progressively upwardly decreasing width, and an upper portion 19 of generally uniform width, said upper portion however increasing progressively upwardly in width over a short length 20 just below its upper (outlet) end. At the extreme upper end 21 of said tobacco duct its width is again reduced, somewhat abruptly, to slightly less than the width of an air-pervious conveyor belt 22 which is driven in a direction normal to the plane of the drawing. Above said belt 22 is asuction box 23' connected to a suction pump (not shown).

In speaking of the width of the duct 17 and other parts it is intended to refer to horizontal dimensions as seen on the drawing-the horizontal dimension of the duct 17 normal to the plane of the drawing is the same at all levers. The duct 17 may be, and preferably is, inclined to the vertical when viewed in elevation from the front of the machine i.e. from the left as shown in the drawing but this fact is irrelevant to consideration of the present invention. This inclination of duct 17, and the configuration of its extreme upper end, have been discussed in various prior specifications, notably US. application Ser. No. 388,212, filed Aug. 7, 1964, now abandoned, and Pat. No. 3,019,793 issued Feb. 6, 1962.

Below the inlet 16 of duct 17 is an air guide duct 24 of rectangular cross-section having a width uniform over most of its length and approximately equal to the width of inlet 16. The upper end of duct 24 meets the end of the plate 15 and at the far side of the inlet 16, almost meets the wall of duct 17, a small gap 25 being left to serve as an air inlet. The remaining two walls 54 and 55 of duct 24 (parallel to the plane of the drawing) are integral with the corresponding walls of duct 17.

From the region of inlet 16, although

ducts

17, 24 extend upwardly and downwardly respectively, both said ducts are inclined from the vertical, so that their upper and lower ends, respectively, are both further forward than is the inlet .16.

At its lower end the duct 24 is flared, the rear wall of duct 24 curving downwardly and rearwardly to allow stem particles or the like falling through duct 24 to reach a stern receiver '26 while the front wall thereof curves out to become horizontal and thus meet at right angles the top edge of a vertically-extending air inlet grille 27; the grille 27 is integral with a horizontal air inlet grille 28 resting on the top edge of the front wall of the stem receiver 26.

The forward inclination of the duct 17 is wholly in its lower portion 18, the upper portion 19 being vertical as viewed in the drawing. Towards the upper end of the upper portion 19, a grille 29 in the rear wall of the duct affords passage for air to a conduit 30 connected to a suction pump 40; this arrangement serves to allow greater volumes of air to be passed through duct 17 than can be satisfactorily passed through the air-pervious conveyor 22 (which latter necessarily affords considerable restriction to air-flow as it must not allow tobacco particles to enter the suction box 23) as set out in detail in US. Pat. No. 3,019,793 issued Feb. 6, 1962.

In operation, air is drawn up duct 24 into duct 17 to the conveyor 22 and suction box 23; below the level of grille 29, the volume of air passing any point in a given time, and hence the air velocity, is increased due to the additional air-fiow into conduit 30. Below grille 29, the air-flow in duct 17 is sufficiently fast to convey tobacco particles upwardly, while above said grille 29 the air-flow may not be fast enough to continue the conveyance of tobacco particles indefinitely but suffices to bring the particles to the belt 22 in view of their considerable velocity immediately before reaching the grille 29.

As the air-stream in duct 24 passes into the inlet 16 of duct 17, it changes direction due to the different inclinations of the two ducts, the air stream in duct 24 being directed towards the inlet of duct 18 at an angle oblique with respect to the longitudinal axis of the adjacent portion of duct 18; and tobacco particles projected into the inlet by the winnower drum 13- enter the air stream transversely in the region where it changes direction and are, therefore, somewhat disordered. Small, light tobacco particles having small momentum in the transverse direction are rapidly entrained by the air stream but heavier particles take longer to change direction and therefore travel farther towards the front of the duct 17 before being entrained. The heaviest particles, pieces of stem and the like, which it is desirable to separate from the remainder of the tobacco so that they do not travel up the duct 17 to form part of the filler collected on belt 22, travel across the inlet 16 to the front wall of the duct 17 and then fall through duct 24 to the stem receiver 26. Such heaviest particles are able to fall thus, it is believed, because immediately above the gap 25 the air at the front of the inlet 16 is moving more slowly than in the more rearward areas of said inlet, due both to the change in direction of the air-stream and to the entry of air through the gap 25; in duct 24, the air velocity is lower than the mean velocity of air in the inlet 16, because the entry of air through gap 25 means there is a smaller volume of air passing through duct 24 in any given time than passes inlet 16, hence the air velocity in duct 24 is lower. Conveniently, the mean air velocity just above gap 25 may be of the order of 11 feet/second.

The machine illustrated in FIG. 2 is in very many respects similar to that of FIG. 1; where parts correspond with those of FIG. 1, the same references are applied thereto and where parts are similar and function similarly to those of FIG. 1, the same numerical references are used followed by a. The following description will be confined to those parts of the machine of FIG. 2 where there are differences to be explained.

Considering firstly the region immediately below the inlet 16a of the tobacco duct 170, it has been found that the velocity of air in this region is a critical factor in obtaining optimum performance. As various factors infiuence the air velocity, it is advantageous to provide some control device and for this purpose we provide an adjustable plate 32 which partially closes the upper end of the air guide duct 24a, leaving a relatively small opening 52 at the side of the duct adjoining the plate 15. The plate 32 is pivotally mounted at its upper end and held at an angle of inclination which is adjustable by a micrometer screw 53.

Below the plate 32, the configuration of the air guide duct 24a and stem receiver 26a is somewhat simpler than that of corresponding parts of the machine of FIG. 1 but this has no noteworthy effect on operation. A grille 27a, corresponding to grille 27 of FIG. 1 but slightly different in form to conform to the altered configuration of the duct 24a, serves as the air inlet for duct 24a. Grille 27a provides suflicient inlet area to ensure that the velocity of air entering substantially transversely of the duct 24a is low enough to have no substantial eifect on the descent of pieces of stem or the like into receiver 26a. No additional air inlet, corresponding to gap 25 of FIG. 1, is found to be necessary in the machine of FIG. 2.

A further modification, as compared with the machine of FIG. 1, is found in the parts of the machine concerned with shorts recirculation. A problem has been found to arise in that larger tobacco particles and foreign bodies may reach the shorts recirculation device which, being only intended to deal with true shorts i.e. very small tobacco particles, is readily clogged by larger particles. Accordingly, we provide a grille 33 over the entry to the shorts recirculation device 11a, the grille 33 being shaped to conform to the curvature of the lower carded drum 4 as a continuation of the masking plate 10. Conveniently the apertures in grille 33 have a maximum dimension of the order of one-quarter of an inch, and the presence of said grille causes a large proportion of any larger particle which may be brought to this part of the machine by the carding of drum 4 to be carried on around said drum and either return to the main tobacco-containing region 2 or travel further in the carding of drum 4 to be subjected again to the action of carded drum 3 and picker drum 9. The presence of grille 33 also tends to promote a smoother, more evenly distributed flow of shorts to the recirculation device 11a.

Furthermore, below the grille 33, a modified form of valve is employed in the inlet of the shorts recirculation device 11. In FIG. 1, a simple form of valve is shown comprising a ciricular-section valve rotor 46 revolving in a closely-fitting block 44, said rotor having two diametrically opposed pockets or scallops 47. Such a valve has been found to be readily jammed and/or damaged if hard foreign bodies (e.g. nails) reach it. In the machine of FIG. 2, a valve 34 is provided which has a different form of rotor 35, comprising a hexagonal-section shaft 36 carrying on each of its six faces a resilient blade 37 extending to the casing in which the rotor runs; a particularly suitable material for the blades 37 is nylon. With rotation of rotor 35 the blades are able to deflect if a hard object such as a nail reaches the valve and allow such object to pass between the blades 37 and the casing without jamming or damage. This form of rotor also, for obvious reasons, gives a smoother flow of recirculated shorts.

It has been found of advantage to provide a degree of control of the quantity of tobacco in the region 2. For this purpose, we provide a photocell 38 at a level corresponding to the maximum height of tobacco found desirable. Such cell 38 will deliver an electrical signal whenever the tobacco rises so high as to produce a material reduction in the illumination of said photocell, and such signal is employed to reduce the rate of delivery of tobacco into the region 2 below the rate at which tobacco is being fed into duct 17a until a further signal from the photocell 38 indicates that the tobacco level has fallen suitably.

Various changes or modifications may be made in the details of the apparatus described without departing from the scope of the invention. Thus for example a variety of arrangements of carded drums and picker rollers may be employed to feed tobacco to the winnower drum 13.

We claim:

1. A device for continuously winnowing a stream of particulate material of varying particle size and weight comprising means for producing an air stream having an air velocity gradient across the width thereof with a maximum velocity on one side and a minimum velocity on the opposite side thereof and particulate feed means for projecting a stream of particles into and across said air stream from the maximum velocity side towards the minimum velocity side thereof whereby the particles are dispersed, the lighter and smaller particles being entrained in the air stream while the heavier and larger particles are projected across the air stream to the side having a minimum air velocity and are separated from the lighter and smaller particles.

2. A device as claimed in claim 1 further comprising means for directing said air stream in a generally upward direction whereby said lighter and smaller particles are entrained in the ascending air stream and said heavier and larger particles fall downwardly through the side of the ascending air stream having a minimum velocity.

3. A device as claimed in claim 1 further comprising air guiding means for directing said air stream along a path having an oblique angle to produce said air velocity gradient.

4. A device for continuously winnowing a stream of particulate material of varying particle size and weight comprising means for producing an air stream along a generally longitudinal axis, particulate feed means for projecting a stream of said particles across said air stream, and air guiding means for directing said air stream past said particulate feed means at an angle oblique with respect to said longitudinal axis whereby the air stream changes direction as it passes the particulate feed means and follows the longitudinal axis creating an air velocity gradient transversely across the air stream with a maximum velocity adjacent the particulate feed means and a minimum velocity remote from the particulate feed means; and the tobacco particles are dispersed, the lighter and smaller particles being entrained in the air stream while the heavier and larger particles are projected across the air stream to the side having a minimum air velocity and are separated from the lighter and smaller particles.

5. A device for continuously winnowing a stream of particulate material of varying particle size and weight comprising an elongated duct, means to produce an air stream through said duct, particulate feed means adjacent one side of said duct for projecting a stream of said particles into and across the said duct, and air guiding means for directing said air stream into said duct and past said particulate feed means at an angle oblique with respect to the longitudinal axis of the portion of said duct adjacent to and beyond said inlet whereby the air stream changes direction as it passes the particulate feed means and enters the duct creating an air velocity gradient across said duct with a maximum velocity on the side of the duct adjacent the tobacco feed means and a minimum velocity on the opposite side thereof, and said stream of tobacco particles are projected in a direction across said air stream and are dispersed, the lighter and smaller particles being entrained in the air stream while heavier and larger particles are projected across the duct to the side having a minimum air velocity and are separated from the lighter and smaller particles.

6. A device for dispersing particulate material of varying particle size and weight in an air stream and for separating therefrom particles above a predetermined size and weight comprising an elongated duct having an inlet, means for drawing an air stream through said duct, air-guide means intersecting said duct from one side thereof for directing said air stream towards said inlet at an angle oblique with respect to the longitudinal axis of the portion of said duct adjacent to and beyond said inlet whereby said air stream changes direction as it enters said inlet creating an air velocity gradient across the width of said duct with a minimum velocity on the side of said duct adjacent said air-guide means and a maximum velocity on the opposite side thereof, and feed means adjacent said duct substantially opposite from said air-guide means for projecting a stream of particulate material of varying particle size and weight towards said inlet at an angle oblique with respect to the longitudinal axis of said duct, said stream of particulate material and said air stream intersecting each other within said duct substantially transversely in the region where said air stream is changing direction whereby said particulate material is dispersed, the light and smaller particles being entrained in said air stream while particles too large and heavy for entrainment by said air stream are projected across the duct to the side adjacent said air-guide means having a minimum air velocity and are separated therefrom.

7. A method for continuously winnowing a stream of particulate material of varying particle size and weight comprising producing an air stream having an air velocity gradient across the width thereof with a maximum velocity on one side and a minimum velocity on the opposite side thereof and projecting a stream of said particles into and across said air stream from the maximum velocity side towards the minimum velocity side thereof whereby the particles are dispersed, the lighter and smaller particles being entrained in the air stream while the heavier and larger particles are projected across the air stream to the side having a minimum air velocity and are separated from the lighter and smaller particles.

8. A method as claimed in claim 7 further comprising the step of directing said air stream in a generally upward direction whereby said lighter and smaller particles are entrained in the ascending air stream and said heavier and larger particles fall downwardly through the side of the air stream having a minimum velocity.

9. A method for dispersing particulate material in an air stream and for separating therefrom particles above a predetermined size and weight comprising drawing an air stream through a duct having an inlet, directing said air stream towards said inlet from one side thereof at an angle oblique with respect to the longitudinal axis of the portion of said duct adjacent to said inlet such that said air stream changes direction as it enters said inlet creating an air velocity gradient across the width of said duct with a minimum velocity on the side where said air stream enters and a maximum velocity on the opposite side thereof, and projecting a stream of particulate material of varying particle size and weight towards said inlet from the side opposite the entry of said air stream at an angle oblique with respect to the longitudinal axis of said duct, said stream of particulate material and said air stream being directed towards each other such that said particulate material intersects said air stream transversely as said air stream is changing direction whereby the lighter and smaller particulate material is entrained in said air stream while particles above a predetermined size and weight are projected across said air stream to said one side where said air stream has a minimum air velocity and are separated therefrom.

10. A continuous rod cigarette-making machine comprising an air-pervious conveyor having a face on which a continuous tobacco filler is formed, an elongated duct extending upwardly to said conveyor, means to produce an air stream through said duct directed towards said conveyor, tobacco feed means adjacent one side of the duct for projecting a stream of tobacco particles of varying particle size and weight into said duct, and air-guiding means for directing said air stream into the duct and past said tobacco feed means at an angle oblique with respect to the longitudinal axis of the portion of said duct adjacent said air-guiding means, whereby the air stream changes direction as it passes the tobacco feed means and enters the duct creating an/ air velocity gradient across said duct with a maximum velocity adjacent the tobacco feed means and a minimum velocity remote from the tobacco feed means, and said stream of tobacco particles is projected in a direction across said air stream and is dispersed, the lighter particles being entrained in the air stream while heavier particles are projected across the duct to the side having a minimum air velocity and are separated from the lighter particles.

11. A continuous-rod cigarette-making machine comprising an air-pervious conveyor having a face on which a continuous tobacco filler is formed, an elongated duct having an inlet spaced from said conveyor and an outlet adjacent to said face, means for applying suction through said conveyor to produce an air stream through said duct towards said face, air-guide means extending from one side of said duct for directing said air stream towards said inlet at an angle oblique with respect to the longitudinal axis of the portion of said duct adjacent to and beyond said inlet whereby said air stream changes direction as it enters said inlet creating an air velocity gradient across the width of said duct with a minimum velocity on the side of said duct adjacent said air-guide means and a maximum velocity on the opposite side thereof, and feed means adjacent said duct substantially opposite from said air-guide means for projecting a stream of tobacco particles of varying particle size and weight towards said inlet at an angle oblique with respect to the longitudinal axis of said duct, said stream of tobacco particles and said air stream intersecting each other within said duct substantially transversely as said air stream is changing direction whereby said tobacco particles are dispersed, the lighter and smaller particles being entrained in said air stream while particles too large and heavy for entrainment by said air stream are projected across the duct to the side adjacent said air-guide means having a minimum air velocity and are separated therefrom.

12. In a continuous-rod cigarette-making machine comprising an air-pervious conveyor having a face on which a continuous tobacco filler is formed, an elongated duct having an inlet spaced from said conveyor and an outlet adjacent to said face, and means for applying suction through said conveyor to produce an air stream through said duct towards said face, the improvement comprising means for dispersing tobacco particles in said air stream and for separating particles above a predetermined size and weight therefrom, said means comprising air-guide means extending from one side of said duct for directing said air stream towards said inlet at an angle oblique with respect to the longitudinal axis of the portion of said duct adjacent to and beyond said inlet whereby said air stream changes direction as it enters said inlet creating an air velocity gradient across the width of said duct with a minimum velocity on the side of said duct, adjacent said air-guide means and a maximum velocity on the opposite side thereof, and feed means adjacent said duct substantially opposite from said air-guide means for projecting a stream of tobacco particles of varying particle size and weight towards said inlet at an angle oblique with respect to the longitudinal axis of said duct, said stream of tobacco particles and said air stream intersecting each other within said duct substantially transversely in the region where the air stream is changing direction whereby said tobacco particles are dispersed, the lighter and smaller particles being entrained in said air stream while particles too large and heavy for entrainment by said air stream are projected across the duct to the side adjacent said air-guide means having a minimum air velocity and are separated therefrom.

13. A continuous-rod cigarette-making machine com- 10 prising an air-pervious conveyor having a face on which a continuous tobacco filler is formed, means for applying suction through said conveyor to produce an air stream directed towards said face, an elongated duct having an inlet spaced from said conveyor and an outlet adjacent to said face whereby said air stream flows through said duct along a first path substantially parallel to the longitudinal axis thereof, the inlet of said duct being of larger cross-sectional area than the outlet thereof, air-guide means used for directing said air stream towards said inlet along a second path at an angle oblique with respect to said first path whereby an air velocity gradient is created across the width of said duct as said air stream changes direction, and feed means angularly spaced from said air-guide means about the periphery of said inlet for projecting a stream of tobacco particles toward said inlet along a third path at an angle oblique with respect to said first path, said second and third paths being on substantially opposite sides of said longitudinal axis of said duct and first path, and said stream of tobacco particles and said air stream substantially transversely intersection each other within said duct as said air stream is changing direction whereby said tobacco particles are fed into the high velocity side of said air stream and are dispersed.

14. A machine as claimed in claim 13 in which the duct is of generally rectangular cross-section throughout its length, the smaller dimension of the rectangle decreasing from the inlet to a point approximately half-way along its length and the cross-section thereafter being constant to a point adjacent the outlet, and the aforementioned smaller dimension again increasing to a maximum and then decreasing until, at the outlet, said smaller dimension is approximately equal to the width of the con veyor.

15. A continuous-rod cigarette-making machine comprising an air-pervious conveyor having a face on which continuous tobacco filler is formed, means for applying suction to said conveyor to produce an air stream directed towards said face, an elongated duct having an inlet spaced from said conveyor and an outlet adjacent to said face whereby said air stream flows through said duct, a further duct associated with the inlet of said elongated duct for directing said air stream towards said inlet at an angle oblique with respect to the longitudinal axis of the portion of said elongated duct adjacent to and beyond said inlet, the cross-section of said further duct being substantially uniform along its length and substantially equal to the cross-section of the inlet of the elongated duct, and feed means angularly spaced from said further duct about the periphery of said inlet for projecting a stream of tobacco particles towards said inlet at an angle oblique with respect to the longitudinal axis of said elongated duct, said stream of tobacco particles and said air stream intersecting each other within said elongated duct substantially transversely as said air-stream is changing direction whereby said tobacco particles are dispersed.

16. A machine as claimed in claim 15 in which said further duct has an inlet spaced from said elongated duct and an outlet adjacent the inlet of said elongated duct, is at an acute angle to the vertical, has its inlet flared to provide a downward facing portion through which heavy tobacco particles separated from said air stream may fall, includes a receiver in which said heavy tobacco particles are received, and a horizontally-facing portion through which air may enter.

17. A continuous-rod cigarette-making machine comprising an air-pervious conveyor having a face on which a continuous tobacco filler is formed, means for applying suction through said conveyor to produce an air stream directed towards said face, an elongated duct having an inlet spaced from said conveyor and an outlet adjacent to said face whereby said air stream flows through said duct, second suction means connected to said duct adjacent the outlet thereof whereby said air stream is produced by both said means for applying suction to said conveyor and said second suction means, air-guide means for directing said air stream towards said inlet at an angle oblique with respect to the longitudinal axis of said duct, and feed means angularly spaced from said air-guide means about the periphery of said inlet for projecting a stream of tobacco particles towards said inlet at an angle oblique with respect to the longitudinal axis of said duct, said stream of tobacco particles and said air stream intersecting each other within said duct substantially transversely as said air stream is changing direction whereby said tobacco particles are dispersed.

18. A continuous-rod cigarette-making machine comprising an air-pervious conveyor movable along a substantially horizontal path and having a bottom face against which a continuous tobacco filler is formed, an elongated duct extending upwards to said conveyor with an inlet spaced from said conveyor, means to produce an airstream through said duct directed towards said conveyor, said air stream producing means comprising first suction means for drawing air through said duct and air-pervious conveyor and a second suction means connected to said duct between said inlet and said conveyor, tobacco feed means adjacent one side of the duct for projecting a stream of tobacco particles of varying particle size and weight into the inlet end of said duct, and means for receiving heavy particles of tobacco which drop out of the inlet of the duct against the action of the air stream, said duct com prising a narrow upper section defined by substantially parallel walls leading to the air-pervious conveyor for conducting air towards said conveyor at a high velocity, and a substantially wider lower section adjacent to said tobacco feed means, defined by upwardly extending walls spaced apart, along a substantial part of the duct, by a distance considerably greater than the distance between the walls defining the upper section of the duct for conducting air towards said narrow upper section at a low velocity compared with the velocity in said upper section, whereby when said tobacco particles are projected into said wider lower section heavy particles such as pieces of stem drop downwards against the flow of air at low velocity into said receiving means while the lighter particles are entrained in said air stream and are carried upwardly into the high velocity air stream in said upper section towards said conveyor.

19. A continuous-rod cigarette-making machine comprising an air-pervious conveyor movable along a subsubstantially horizontal path and having as bottom face against which a continuous tobacco filler is formed, an elongated duct extending upwards to said conveyor with an inlet spaced from said conveyor, means to produce an air stream through said duct directed towards said conveyor, said air stream producing means comprising first suction means for drawing air through said duct and air-pervious conveyor and a second suction means connected to said duct between said inlet and said conveyor, tobacco feed means adjacent one side of the duct for projecting a stream of tobacco particles of varying particle size and weight into the inlet end of said duct in a direction inclined from the vertical and towards the opposite side of said duct, and means for receiving heavy particles of tobacco which drop out of the inlet of the duct against the action of the air stream, said duct comprising a narrow upper section defined by substantially parallel walls leading to the air-pervious conveyor for conducting air towards said conveyor at a high velocity, and a substantially wider lower section adjacent to said tobacco feed means, defined by upwardly extending walls spaced apart, along a substantial part of the duct, by a distance considerably greater than the distance between the walls defining the upper section of the duct for conducting air towards said narrow upper section at a low velocity compared with the velocity in said upper section, whereby when said tobacco particles are projected into said wider lower section heavy particles such as pieces of stem drop downwards against the flow of air at low velocity into said receiving means while the lighter particles are entrained in said air stream and are carried upwardly into the high velocity air stream in said upper section towards said conveyor, said tobacco feed means comprising a carded drum for feeding a carpet of tobacco in a predetermined direction, a picker roller situated adjacent to the carded drum at a position at which rotation of the carded drum moves the carpet of tobacco in a downward direction, a guide plate onto which the picker roller transfers the tobacco from the drum, and a projector roller for projecting the tobacco from the guide plate and into the inlet end of said duct, said guide plate being concave whereby the tobacco first passes along the guide plate with a downward component of movement and is then deflected upwards by the concave shape of the guide plate.

20. A cigarette-making machine comprising a tobacco shower channel for receiving tobacco and for conveying it in the form of a narrow stream towards a garniture, a drum for feeding a carpet of tobacco towards said shower channel; a stationary guide plate extending between said drum and said shower channel, said guide plate having a concave surface as seen in a section normal to the axis of the drum, rotary picker means for removing the carpet of tobacco from the drum and projecting the tobacco along the surface of said guide plate so that the tobacco changes direction as it moves along the concave surface of the guide plate from a leading portion toward a trailing portion of said guide plate; and a projector roller located downstream of said rotary picker means and adjacent the surface of said guide plate for engaging tobacco between said rotary picker means and the surface of said guide plate to mechanically project said tobacco from said plate in the direction of said trailing portion of said plate and into one end of said shower channel and towards the other end of the shower channel.

21. A continuous-rod cigarette making machine comprising:

(a) an air-pervious conveyor movable along a substantially horizontal path and having a bottom face against which a continuous tobacco filler is formed,

(b) elongated duct means extending upwardly to said conveyor with an inlet spaced from said conveyor,

(c) the cross-sectional area of said inlet and the portion of said'duct means adjacent said inlet being substantially greater than the cross-sectional area of the portion of said duct means adjacent said conveyor,

(d) means for projecting a stream of tobacco particles of varying particle size and weight through the inlet into the adjacent portion of said duct means having a greater cross-sectional area, and

(e) means for producing an air stream directed through said inlet into said duct means toward said conveyor at a high volume flow rate,

(f) whereby a relatively low velocity section of the air stream is maintained in the inlet and the portion of said duct means adjacent said inlet and a relaatively high velocity section of the air stream is maintained in the portion of said duct means adjacent said conveyor, and the heavier and larger particles of the tobacco such as pieces of stem fall downwardly against the low velocity flow of air in the portion of said duct means adjacent said inlet while the lighter and smaller particles are entrained in said air stream and are carried upwardly into the high velocity section of said air stream toward said conveyor.

22. A cigarette making machine as claimed in claim 21 further comprising means for receiving said heavier and larger tobacco particles which fall through said inlet, the path of said heavier and larger particles between said inlet and receiving means being unrestricted whereby any air flow in said path is maintained at a relatively low velocity to prevent said heavier and larger particles from being entrained.

23. A device as claimed in claim 22 further comprising air-guide means for directing said air stream toward said inlet along the path of said heavier and larger tobacco particles falling from said inlet towards said receiving means.

24. A device as claimed in claim 23 wherein said airguide means comprises a further duct, one end of which is spaced from the inlet of said duct means, said further duct extending generally downwardly therefrom towards said receiving means.

25. A device as claimed in claim 22 wherein said projecting means is positioned outside the path between said inlet and said receiving means whereby air flow along the path of said heavier and larger tobacco particles remains unrestricted and at a relatively low velocity.

26. A continuous-rod cigarette making machine according to claim 18 wherein said tobacco feed means comprises a guide plate, means for transferring tobacco in a downward direction onto said guide plate, and means for projecting tobacco from the guide plate and into the inlet end of said duct, said guide plate being concave whereby the tobacco first passes along the guide plate with a downward component of movement, and then is deflected upwardly by the concave shape of the plate.

27, A cigarette-making machine according to claim 20 wherein the clearance between the periphery of said projector roller and the concave surface of said guide plate is such that said tobacco is gripped between said projector roller and said concave surface of said guide plate before said tobacco is projected into said shower channel.

28. A machine according to claim 18 in which the means for producing an air stream through the duct comprises a first section means for drawing air through and above the air-pervious conveyor and a second suction means connected to the upper part of said elongated duct.

29. A cigarette making machine according to claim 20 further comprising a second plate having a surface extending between said drum and said shower channel adjacent 14 the side of said rotary picker means and projector roller opposite said guide plate.

30. A cigarette making machine according to claim 29 wherein said stationary guide plate and said second plate form a chamber havin a tapered cross-section with said rotary picker means and said projector roller contained therein.

31. A cigarette making machine according to claim 29 wherein said surface of said second plate is concave as seen in a section normal to the axis of the drum.

32. A cigarette making machine according to claim 20 in which said trailing portion of the guide plate is curved, as seen in cross-section normal to the axis of the drum, so as to form substantially part of a cylinder having its axis coinciding with the axis of the projector roller.

References Cited UNITED STATES PATENTS 3,028,866 4/1962 Molins 131109 R 651,374 6/1900 Ludington 131109 R U X 2,948,281 8/1960 DeVoto (it al. 131-109 R X 3,019,793 2/1962 Labbe 131-84 B 3,030,965 4/1962 Labbe 131110 X 3,034,514 5/1962 Pinkham 131-110 X 3,088,468 5/1963 Labbe 131-110 X 3,092,117 6/1963 Labbe 131-84 BX FOREIGN PATENTS 218,648 11/1958 Australia 13184 C 572,389 11/1958 Belgium 13184 B 683,400 3/1964 Canada 131110 648,881 11/1962 Italy 131110 366,786 2/1963 Switzerland 13184 B JOSEPH S. REICH, Primary Examiner US. Cl. X.R. 13l84 B, 21 A