US3757800A

US3757800A - Apparatus for classifying fragments of tobacco

Info

Publication number: US3757800A
Application number: US00098349A
Authority: US
Inventors: H David; W Rudszinat
Original assignee: Hauni Werke Koerber and Co KG
Current assignee: Koerber AG
Priority date: 1969-12-22
Filing date: 1970-12-15
Publication date: 1973-09-11
Anticipated expiration: 1990-09-11
Also published as: FR2073082A5; FR2073081A5; DE2060099A1; DE2060100A1

Abstract

Apparatus for segregating relatively light shredded tobacco leaf laminae from heavier particles of tobacco ribs and stem has a feeding device which showers a mixture of lighter and heavier particles onto the upper stretch of a rapidly moving classifying belt which propels the particles beyond one of its ends whereby the heavier particles are segregated from lighter particles because their flight span is longer than that of the shreds. The lighter particles are thereupon spread apart by a battery of horizontal winnowers of rectangular cross-sectional outline which distribute such particles on the upper stretch of a collecting belt which moves counter to the direction of travel of the upper stretch of the classifying belt. The feeding device has a carded belt which transports a sliver of intermixed lighter and heavier particles and from which a picker roller removes successive increments of the sliver to shower the particles onto the upper stretch of the classifying belt. The heavier particles are collected in a trough and are evacuated by a rotating screw.

Description

United States Patent 1 91 David etal. 1 1 Sept. 11, 1973 54] APPARATUS FOR CLASSIFYING 550,101 11/1895 Flanegin 131/109 R ux FRAGMENTS 0F TOBACCO FOREIGN PATENTS OR AlPPLlCATlONS [75] Inventors: Harry David, Hamburg; Willy 887,496 l/1962 Great Britain 131 109 R Rudszinat, Dassendorf, both of 240,574 11/1911 Germany 131/109 R Germany [73] Assignee: Hanne-Werke Korher & Co. KG,

Hamburg, Germany [22] Filed: Dec. 15, 1970 [21] Appl. No.: 98,349

[30] Foreign Application Priority Data Dec. 22, 1969 Great Britain 62,446/69 {52] US. Cl. 131/109 B, 131/21 A, 131/21 B, 1 209/120, 131/110 [51] Int. Cl. A24c 1/02 [58] Field of Search 131/108, 109 R, 109 AB, 131/109 B, 110, 146, 120; 209/120 [56] References Cited UNlTED STATES PATENTS 2,151,527 3/1939 Podmore 131/146 UX 2,230,195 l/l941 Warren 131/109 B 1,326,547 12/1919 Teale 131/109 B 2,212,265 8/1940 Downing, .lr. 209/120 2,211,096 8/1940 Brown 209/120 X 716,449 12/1902 MacDonald 131/109 R UX 406,611 7/1889 Allison 131/109 R UX 2,731,673 1/1956 Wallace 131/110 X Primary Examiner Joseph S. Reich Attorney-Michael S. Striker [57] ABSTRACT Apparatus for segregating relatively light shredded tobacco leaf laminae from heavier particles of tobacco ribs and stem has a feeding device which showers a mixture of lighter and heavier particles onto the upper stretch of a rapidly moving classifying belt which propels the particles beyond one of its ends whereby the heavier particles are segregated from lighter particlesbecause their flight span is longer than that of the shreds. The lighter particles are thereupon spread apart by a battery of horizontal winnowers of rectangular cross-sectional outline which distribute such particles on the upper stretch of a collecting belt which moves counter to the direction of travel of the upper stretch of the classifying belt. The feeding device has a carded belt which transports a sliver of intermixed lighter and heavier particles and from which a picker roller removes successive increments of the sliver to shower the particles onto the upper stretch of the classifying belt. The heavier particles are collected in a trough and are evacuated by a rotating screw.

9 Claims, 1 Drawing Figure PATENTED 1 1975 3.757. 800

m M m wall-r Raga/"' A TTORNEV APPARATUS FOR CLASSIFYING FRAGMENTS OF TOBACCO BACKGROUND OF THE INVENTION The present invention relates to apparatus for segregating lighter particles from a mixture of lighter and heavier particles, particularly for segregating shreds of tobacco leaf laminae from a mixture which contains such shreds in random distribution with fragments of tobacco ribs, stem, birds eyes and/or other heavier tobacco particles.

It is already known to segregate lighter and heavier tobacco particles by showering a mixture of such particles onto one or more rapidly rotating winnowers which are intended to propel the heavier particles along first paths and the lighter particles along second paths to thus effect a separation of lighter and heavier particles. As a rule, the winnowers are rollers which are provided with outwardly extending projections in the form of strips, ribs, vanes, blades or the like. The projections prevent the winnowers from propelling all lighter particles in a first direction and all heavier particles in a second direction so that the classifying action is not entirely satisfactory and the resulting accumulations or batches which respectively contain the major part of lighter and heavier particles must be subjected to one or more secondary classifying actions. Furthermore, the force with which the particles are propelled by different portions of such winnowers varies within a wide range which also contributes to an unsatisfactory classifying action. The flight spans of ligher particles are often as long as the flight spans of heavier particles, i.e., such flight spans are not determined exclusively by the specific weight of particles and/or by the resistance which the particles offer to propulsion through the surrounding air.

SUMMARY OF THE INVENTION An object of the invention is to provide a novel and improved apparatus for segregating lighter particles which are intermixed with heavier particles, particularly for segregating shreds of tobacco leaf laminae from fragments of tobacco ribs, stem or birds eyes in such a way that all or nearly all lighter particles are effectively separated from heavier particles in a single separating or classifying zone.

Another object of the invention is to provide the apparatus with novel and improved winnowers.

A further object of the invention is to provide the apparatus with novel and improved means for propelling a mixture of lighter and heavier particles in such a way that all or nearly all lighter particles are immediately and effectively segregated from the heavier particles.

An additional object of the invention is to provide an apparatus which is particularly suited for segregating from a mixture of lighter and heavier tobacco particles those particles which can be immediately introduced into a-machine for making a continuous filler stream to be used in the manufacture of wrapped tobacco rod sections.

The improved apparatus comprises a classifying conveyor including an endless flexible belt having a particle supporting and advancing stretch, drive means for rapidly moving the stretch lengthwise in a predetermined direction, a feeding device for continuously supplying to the stretch a mixture of randomly distributed lighter and heavier particles which form on the stretch a layer advancing with and beyond the downstream end of the stretch whereby the flight span of heavier particles is longer than the flight span of lighter particles so that the lighter particles are effectively separated from the heavier particles, and means for collecting the thus separated lighter particles independently of the heavier particles.

The apparatus further preferably comprises a rotary pressing member which overlies and rests on the layer of intermixed particles close to the downstream end of the stretch of the classifying conveyor, and a battery of preferably parallel rotary spreading members of winnowers which are located in the path of lighter particles leaving the classifying conveyor and serve to distribute the lighter particles over a substantial part of the collecting means. Each winnower is preferably of polygonal, most preferably of rectangular cross-sectional outline.

The novel features which are considered as characteristic of the invention are set forth in particular in the appended claims. The improved classifying apparatus itself, however, both as to its construction and its mode of operation, together with additional features and advantages thereof, will be best understood upon perusal of the following detailed description of certain specific embodiments with reference to the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING The single FIGURE is a schematic side elevational view of a distributor which serves to supply tobacco shreds to a cigarette rod making machine and comprises a classifying apparatus which embodies the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 illustrates a distributor for a cigarette making machine. The purpose of the distributor is to withdraw fragmentized tobacco leaves from a large or main supply l and to convert the thus withdrawn mixture of lighter and heavier tobacco particles into a uniform narrow tobacco filler stream 3 which is ready for wrapping into cigarette paper without trimming or after trimming. The resulting wrapped tobacco filler rod is thereupon severed to yield plain cigarettes of desired length. The main supply 1 contains interlaced tobacco shreds and heavier particles which may or may not form coherent clumps or batches. The conversion of particles which are withdrawn from the main supply 1 into the filler stream 3 takes place in several stages including the formation of a uniform silver or carpet 2 which is thereupon relieved of heavier particles 2a to form a carpet 2b. The latter is converted into the tiller stream 3. The main supply 1 is replenished with fragmentized tobacco which is supplied by a pneumatic delivery hopper 6.

The main supply 1 is stored in a container 4 which is located below the outlet of the delivery hopper 6. The intermixed lighter and heavier particles which are withdrawn from the main supply I are accumulated into several smaller supplies or piles including a relatively I small last or final supply 7 and three intermediate supplies 8, 9 and 11. The quantity of tobacco particles in each of the intermediate supplies 8, 9, 11 is less than in the main supply 1 (when the latter contains a maximum quantity of particles) but exceeds the quantity of particles in the last supply 7. The means for transporting tobacco particles between the intermediate supplies 8, 9, 11 as well as to and away from the final supply 7 comprises an endless conveyor belt 13 provided with a carding l2 and trained over rollers 14, 16, 17 at least one of which is driven, preferably at a constant speed, to advance the particles in the direction indicated by arrows.

A lifting conveyor 18 includes an endless belt 23 trained over rollers 19, 21 at least one of which is driven at a variable speed so that the carding 22 on the right-hand stretch of the belt 23 transports a continuous layer of particles past a tobacco leveling refuser wheel 28 having a set of elastic tongues or blades 27.

' The thus equalized layer is beaten out of the carding 22 by a rotating picker or comb-off roller 26 which propels the removed particles into a funnel-shaped receptacle 24 for the first or largest intermediate supply 11. That stretch of the conveyor belt 13 which extends between the rollers 16 and 17 constitutes a moving wall of the receptacle 24. The picker roller 26 can be replaced with a rotary brush or the like. The parts 18, 26 and 28 together constitute a withdrawing unit which draws from the main supply 1 a substantially uniform layer of tobacco particles for delivery to the first intermediate supply 11.

The receptacle 24 accommodates or supports a level detector or indicator including one or more light sources (not shown) and one or more photosensitive receivers 29 which produce signalswhenever the intermediate supply 11 in the receptacle 24 rises to a predetermined maximum permissible level or descends below a minimum permissible level. The illustrated receiver 29 is connected with the input of a regulating unit 31 which serves to vary the speed of the conveyor belt 23 so as to maintain the amount of tobacco particles in the intermediate supply 11 within a desired range. The regulating unit 31 comprises a time delay relay 32, a preamplifier 33 which is in series with the relay 32, a power output amplifier 34 which is in series with the preamplifier 33, and a variable-speed electric motor 36 which drives the roller 21 for the belt 23.

The means for removing a uniform sliver 2 of tobacco particles from the last supply 7 comprises the upper stretch of the belt 13 on which the supply 7 rests and a tobacco leveling refuser wheel 35 which is analogous to the refuser wheel 28. The sliver 2 is removed from the belt 13 by a rotating picker roller or removing roller 40 (which can be replaced with a rotating brush) whereby the particles of the sliver 2 are showered onto a classifying conveyor 189 here shown as including an endless belt 89 trained over

rollers

87, 88. The roller 87 is driven at a high speed by a shaft 87a so that the particle supporting and advancing upper stretch 89a of the belt 89 travels in the direction indicated by an arrow F.

The means for removing a layer of tobacco particles from the first intermediate supply 11 comprises the aforementioned inclined stretch of the belt 13 (between the rollers 16 and 17) and a rotary refuser wheel 47 which is preferably identical with the wheels 28, 35 and returns the excess of particles back into the receptacle 24. The thus equalized layer is fed to the second intermediate supply 9 which is supported by the upper stretch of the belt 13 and from which such upper stretch withdraws a continuous layer which is equalized by a refuser wheel 46. The equalized layer which is permitted to advance beyond the refuser wheel 46 is admitted to the third intermediate supply 8 which rests on the upper stretch of the belt 13 between the supplies 7 and 9. The upper stretch of the belt 13 cooperates with a further refuser wheel 44 to withdraw from the supply 8 a continuous layer of tobacco particles which are admitted to the last layer 7.

The supplies 7, 8, 9 are respectively located below level indicators or detectors each of which includes at least one light source (not shown) and at least one photosensitive receiver 37, 38, 39, respectively. The illustrated receiver 37 is connected with the input ofa regulating unit 41 which serves to adjust the refuser wheel 44 and to thus regulate the thickness of the layer which is being withdrawn from the last intermediate supply 8. The regulating unit 41 comprises a time delay relay 48, an amplifier 49 and a servomotor 51 which can move the refuser wheel 44 toward or away from the upper stretch of the belt 13, depending upon whether the amount of tobacco in the last supply 7 is above a maximum permissible level or below a minimum permissible level. The detector including the receiver 37 is perferably a so-called maximum and minimum level indicator which can transmit appropriate signals in response to depletion of the supply 7 to a minimum permissible level and in response to a rise of the supply 7 beyond a maximum permissible level. In this way, the supply 7 invariably contains an amount of tobacco particles which is within a desired range.

The level indicators including the photoelectric receivers 38, 39 are preferably identical with the level indicator for the last supply 7. The receiver 38 is connected with the input of a regulating unit 42 having a time delay relay 52, an amplifier 54 and a servomotor 57 which can move the refuser wheel 46 toward or away from the upper stretch of the belt 13 to thereby control the amount of tobacco particles in the last intermediate supply 8.

The receiver 39 is connected with the input ofa regulating unit 43 which includes a time delay relay 53, an amplifier 56 and a servomotor 58 which can move the refuser wheel 47 toward or away from the adjacent inclined stretch of the belt 13 to thereby insure that the amount of tobacco particles in the second intermediate supply 9 remains within a desired range. The means for rotating the refuser wheels 28, 47, 46, 44, 35, the picker rollers 26, 40, and at least one of the rollers l4, 16, 17 is not shown in FIG. 1. The servomotors 51, 57, 58 preferably include electromagnets whose armatures are coupled to the driven shafts of the respective refuser wheels and can move such shafts sideways (toward or away from the adjacent stretches of the belt 13) with reference to suitable guides, not shown. It is clear, however, that the servomotors 51, 57, 58 may comprise variable-speed electric motors which can shift the refuser wheels through the intermediary of suitable transmissions so that the shaft of each adjustable refuser wheel can be moved sideways between a finite or infinite number of positions. All that counts is to provide the distributor with means which can regulate the rate of transport of tobacco particles between successive supplies 1, ll, 9, 8 and 7.

The upper stretch 89a of the belt 89 accumulates a layer 2' whose particles are advanced in the direction indicated by the arrow F to be propelled, beyond the end turn at the roller 88 (which is rotated in the direction indicated by the arrow D) so that the heavier particles 2a (for example, those consisting of fragments of ribs, stern and/or so-called birds eyes) are propelled into a collecting trough 94a containing a rotary evacuating conveyor here shown as a screw 94. The flight span of heavier particles 2a is longer than the flight span of lighter particles 2b which descend into a spreading zone A containing three parallel horizontal rotary spreading members or winnowers 91, 92, 93 of polygonal (preferably rectangular) cross-sectional outline. The winnowers 91-93 distribute the lighter particles 2b on the upper stretch 95a of an endlessbelt 95 whereon such particles form a wide carpet 2b of uniform height and width. Such carpet is transported in the direction indicated .by the arrow G and its particles are showered in a stream-forming zone H to enter a guide channel 98 which accumulates the aforementioned filler stream 3. The character 8 denotes the discharge end of the stretch 89a where the heavier particles 2a are automatically separated from the lighter particles 2b. The endless belt 95 forms part of a collecting conveyor 195 for tobacco shreds.

A pressing roller 90 is mounted on a pivotable lever 90a and rests on the layer 2 at a level above the roller 88. The roller 90 is an idler roller and the direction of its rotation is indicated by an arrow C, i.e., the

rollers

88, 90 rotate in opposite directions. The winnowers 91-93 rotate in directions indicated by arrows E, namely, counter to the direction of rotation of the roller 89. The belt 95 is trained over

rollers

96, 97 the latter of which is driven, preferably at a constant speed, by a shaft 97a. The width of the guide channel 98 decreases in a downward direction, and its bottom wall supports a narrow endless tapeor band 99 which transports the filler stream 3 lengthwise (at right angles to the plane of FIG. 1) toward a wrapping and rod forming-mechanism of conventional design.

It will be noted that the direction of rotation of the winnowers 91-93 (arrows E) is counter to the direction of rotation (arrow D) of the roller 88. Also, the direction of travel of the upper stretch 89a (arrow F) is counter to the direction of travel of the upper stretch 95a (arrow G). This reduces the overall length of the classifying apparatus whose feeding device includes the carded belt 13 and the removing roller 40. The stretches 89a, 95a and the axes of the winnowers 91-93 are preferably located in horizontal planes.

The pressing roller 90 can be biased against the upper side of the layer 2' by one or more springs 90b or the like.

The operation:

The delivery hopper 6 admits a mixture of lighter and heavier tobacco particles into the container 4 so that the latter accumulates a main supply 1 wherein the particles are interlaced and normally form at least some batches of coherent particles. The motor 36 is started to drive the belt23 of the lifting conveyor 18 so that the carding22 draws from the supply 1 a continuous layer which is equalized by the refuser wheel 28 and removed from. thecarding by the picker roller 26 to enter the receptacle 24 where it accumulates to form the first intermediate supply 11. When the supply 11 rises to the level of the photosensitive receiver 29, the latter produces a signal which causes the power output amplifier 34 in the regulating unit 31 to receive little or no current whereby the variable-speed motor 36 is either idle or drives the roller 21 at a low speed. The time delay relay 32 insures that the speed of the motor 36 is not changed in response to short-lasting interruptions of the light beam between the light source and the receiver 29, for example, in response to such interruptions which are caused by tobacco particles showered into the receptacle 24 by the picker roller 26.

The belt 13 is driven at a constant speed and its inclined stretch draws from the intermediate supply 1] a continuous layer of particles which is equalized by the refuser wheel 47 and is advanced by the upper stretch of the belt 13 to form the intermediate supplies 9, 8 and the last supply 7. As shown in FIG. 1, the supply8 contains more tobacco than the supply 7 but less tobacco than the supply 9. The latter contains less tobacco than.

the supply 11. Once the upper stretch of the belt 13 accumulates the supplies 9, 8 and 7, it begins to draw from the last supply 7 a continuous and substantially uniform homogeneous sliver 2 which is removed by the picker roller 40 and is showered continuously onto the upper stretch 89a of the belt 89.

The level indicators including the receivers 37, 38, 39 respectively scan the supplies 7,8, 9 and initiate adjustments in the position of the refuser wheel 44, 46

and/or an when the amount of tobacco particles in the corresponding supply rises above or decreases below a permissible value. The receiver 29 scans the intermediate supply 11 and initiates adjustments in the speed of the motor 36 and thus insure that the amount of tobacco particles in the receptacle 24 does not rise above or decrease below a permissible range. As mentioned above, the level indicators which include the receivers 37, 38, 39 are preferably desired to move the corresponding refuser wheels toward or away from the adjacent portions of the belt 13.

The classifying belt 89 of the conveyor 189 is, driven by the shaft 87a at a relatively high speed so as to move its upper stretch 89a in the direction indicated by the arrow F whereby the inertia of the heavier particles 2a causes such particles to travel against the thread of the screw 94 which moves them to a collecting or further processing station. The separation of heavier particles 2a from the lighter particles 2b takes place at the discharge end B of the stretch 89a (immediately downstream of the pressing roller 90) and the lighter particles 2b enter the spreading zone A tobe distributed by the winnowers 91-93 and to form on the upper stretch 95a of the collecting belt 95 a wide and homogenous carpet 2b which is transported in the direction indicated by the arrow G. The lighter particles 2b contain mainly fragments or shreds of tobacco leaf laminae.

The purpose of the pressing roller 90 is to insure, in cooperation with the roller 88, that the lighter and heavier particles 21;, 2a which reach the discharge end 8 travel at the same speed and in the same direction. Thus, the

parts

88, 90 cooperate to guarantee that the particles 2a, 2b will travel along different paths solely as a result of differences in their nature to thus insure a highly accurate classifying action between ribs, stern and birds eyes on the one hand and fragments or shreds of tobacco leaf laminae on the other hand.

The winnowers 91-93 bring about further homogenization of lightweight material which is discharged from the stretch 89a of the classifying belt 89 and enters the spreading zone A. Consequently, the carpet 2b contains uniformly distributed lighter particles which can be showered into the guide channel 98 toform on the tape 99 a narrow fillerstream 3 which can be introduced into a wrapping mechanism.

An advantage of the structure which supplies particles of tobacco to the carded belt 13 and of the feeding device including the belt 13 and the picker roller 40 is that the upper stretch 89a of the belt 89 receives a stream of loose particles which can be readily segregated into lighter and heavier particles. It was found that the segregation which is carried out downstream of the discharge end of the stretch 89a is very satisfactory for the formation of a filler stream 3 which contains shreds of tobacco leaf laminae. It was further found that the polygonal winnowers 91-93 are much more satisfactory than presently known bladed or ribbed winnowers. The winnowers 9l-93 need not segregate lighter particles 212 from the heavier particles 2a; they serve to insure satisfactory distribution of lighter particles on the particle intercepting upper stretch 95a of the collecting belt 95.

Withoutfurther analysis, the foregoing will so fully reveal the gist of the present invention that others can,

I by applying current knownledge, readily adapt it for various applications without omitting features which fairly constitute essential characteristics of the generic and specific aspects of our contribution to the art and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the claims.

What is claimed as new and desired to be protected by Letters Patent is set forth'in the appended claims:

1. Apparatus for segregating lighter and heavier tobacco particles which form a mixture of such particles, particularly for segregating particles of 'ribs and stem from shreds of tobacco leaf laminae, comprising a classifying conveyor including a plurality of rotary elements and an endless flexible belt trained over said rotary elements and having a particle supporting and advancing upper stretch, said upper stretch having a discharge end; drive means for moving said upper stretch lengthwise; a feeding device including a conveyor arranged to accumulate and transport a sliver consisting of a mixture of lighter and heavier tobacco particles and to supply such mixture to said upper stretch whereon the lighter and heavier particles form a layer advancing toward and beyond said discharge end and into a spreading zone located downstream of said upper stretch; a rotary member located in the region of said discharge end and opposite said upper stretch so as to engage at least some of the particles on said upper stretch and to be rotated thereby so that rotation of said rotary member together with movement of said upper stretch of said endless flexible belt cause propulsion of all tobacco particles into said spreading zone at a predetermined speed whereby the flight span of the heavier particles is longer than the flight span of lighter particles with attendant separation of lighter and heavier particles; first collecting means for collecting the thus separated lighter particles, including a conveyor having a moving intercepting portion arranged to collect the separated ligher particles in the form of a carpet; and second collecting means for collecting the separated heavier particles.

2. Apparatus as defined in claim 1, wherein said elements are rollers, one of said rollers being adjacent to said discharge end and said rotary member overlying the layer on said stretch in the region of said one roller.

3. Apparatus as defined in claim 2, wherein said rotary member is mounted to ride on said layer.

4. Apparatus as defined in claim 1, further comprising spreading means interposed in said spreading zone in the path of lighter particles between said classifying conveyor and said first collecting means to distribute the lighter particles over a substantial part of said intercepting portion.

5. Apparatus as defined in claim 4, wherein said spreading means comprises a battery of rotary spreading members.

6. Apparatus as defined in claim 5, wherein said spreading members are winnowers each having a polygonal cross-sectional outline.

7. Apparatus as defined in claim 5, wherein said upper stretch of said belt is located in a first substantially horizontal plane and the axes of said spreading members are located in a second substantially horizontal plane, said intercepting portion for separated lighter particles being located in a third substantially horizontal plane.

8. Apparatus as defined in claim 7, wherein said conveyor of said first collecting means comprises a second endless belt having an upper stretch which constitutes said intercepting portion, and drive means for moving said last mentioned upper stretch in a direction counter to the direction of movement of said upper stretch of said first mentioned belt.

9. Apparatus as defined in claim 8, wherein one of said rotary elements comprises a roller adjacent to said discharge, said roller being arranged to rotate in a first direction and said spreading members being arranged to rotate in a second direction.

Claims

1. Apparatus for segregating lighter and heavier tobacco particles which form a mixture of such particles, particularly for segregating particles of ribs and stem from shreds of tobacco leaf laminae, comprising a classifying conveyor including a plurality of rotary elements and an endless flexible belt trained over said rotary elements and having a particle supporting and advancing upper stretch, said upper stretch having a discharge end; drive means for moving said upper stretch lengthwise; a feeding device including a conveyor arranged to accumulate and transport a sliver consisting of a mixture of lighter and heavier tobacco particles and to supply such mixture to said upper stretch whereon the lighter and heavier particles form a layer advancing toward and beyond said discharge end and into a spreading zone located downstream of said upper stretch; a rotary member located in the region of said discharge end and opposite said upper stretch so as to engage at least some of the particles on said upper stretch and to be rotated thereby so that rotation of said rotary member together with movement of said upper stretch of said endless flexible belt cause propulsion of all tobacco particles into said spreading zone at a predetermined speed whereby the flight span of the heavier particles is longer than the flight span of lighter particles with attendant separation of lighter and heavier particles; first collecting means for collecting the thus separated lighter particles, including a conveyor having a moving intercepting portion arranged to collect the separated ligher particles in the form of a carpet; and second collecting means for collecting the separated heavier particles.