US2736319A - Tobacco-feeding apparatus - Google Patents

Description

Feb. 28, 1956 D. ;w. MoLlNs 2,736,319

TOBACCO-FEEDING APPARATUS Filed June 18, 1954 ATTORNE YS United States Patent O 'roBAcco-FEEDnsG APPARATUS Desmond Walter Molins, Deptford, London, England, as-

signor to Molins Machine Company Limited, London, England, a British company This invention concerns improvements in or relating to tobacco-feeding apparatus, e. g. for cigarette-making machines of the continuous rod type.

In such feeding mechanisms cut tobacco is placed in a hopper and is fed therefrom on to an endless band or in some cases on to a web of cigarette-paper. Usually the tobacco so fed is picked by -a fast-rotating picker roller, and in some cases the tobacco after leaving the picker is winnowed, that is, it is engaged by moving vanes and thrown upwardly and forwardly thereby to enable heavier particles, such as pieces of stalk, to be separated from the lighter tobacco so that they can be excluded from the tobacco from which the cigarettes are to be made. This is usually done by arranging a wall or chute in such a position that as tobacco is thrown upwardly and forwardly, the heavier particles, which owing to their greater mass travel further, are carried over the wall, while the lighter particles fall short of the upper edge of the wall. Usually a compartment is provided behind the wall to receive the heavier particles.

The pieces of tobacco stalk which sometimes occur in cut tobacco are not only heavier than the shreds of tobacco leaf, but also harder. It is an object of the present invention to make use of these characteristics in providing improved apparatus for separating pieces of stalk from the tobacco shreds which it is desired to incorporate in cigarettes.

According to the present invention there is provided tobacco-feeding apparatus comprising a smooth and relatively hard travelling conveyor surface, and means to cause showered cut tobacco to strike said surface at an anglesuch that hard particles of tobacco, such as pieces of stalk, tend to bounce and slip rearwardly over said surface so as to fall rearwardly from the latter,'while softer particles tend to remain on said surface so as to be carried forwardly by it.

The said means may comprise a winnowing device arranged to throw cut tobacco upwardly and in a direction such `as to cause the tobacco to fall towards said surface while having a component of movement in the opposite direction to that in which the surface is moving, whereby hard particles such as stalks, which owing to their greater mass, travel further than lighter particles, tend to strike the rear part of the said surface, while lighter particles tend to strike theforward part of said surface., V

v The saidr surface may be so 'located as to discharge tobacco carried thereon on to a moving conveyor in the trough of a cigarette-making machine.

The said surface may be the upper surfacevof an endless conveyor band comprising polyvinyl chloride.

The said surface may be caused to be moved in timed relationship with the said moving conveyor in the trough and stop when said moving conveyor stops, whereby tobacco moving so as to fall on said surface at the moment when the said moving conveyor stops is prevented from falling on the latter.

A wall may be located above said surface to assist 2,736,319 ce Patented Feb. 28, 1956 in segregating heavier from lighter tobacco particles falling towards said surface, the Wall being spaced apart from the surface to permit tobacco which falls on the surface to the rear of the wall to be carried forwardly by said surface.

Apparatus according to the invention will now be described by way of example with reference to the accompanying drawing, which shows a section through tobaccofeeding apparatus in a cigarette-making machine.

Tobacco is fed from a hopper into the teeth of a carded roller 1 on which it is formed into an even layer, or carpet, as it is sometimes called. The tobacco is picked from the teeth of the roller 1 by a fast-rotating picker roller 2 which throws the tobacco against a rotating winnowing element having vanes 3. A guide 4 guides the tobacco from the roller 2 to the winnower. The vanes 3 of the winnower, which rotate in the direction shown by the arrow, throw the tobacco upwardly and forwardly.

An endless conveyor band 5 is arranged to pass over three rollers 6, 7 and 8 which are rotated so as to move the band in the direction indicated by the arrow. The band 5 is made of the plastic material known-'as polyvinyl chloride, and has a smooth and somewhat hard surface. The part of the band from the roller 6 to the roller 7 is arranged at `an angle of 25 to the horizontal, sloping upwardly in its direction of movement. The part of the band extending between the roller 7 and the roller 8 slopes downwardly. A vertical wall 9 is located above the band 5, with its lower edge clear of the bandas shown.

Between the endless band 5 yand the winnower a pair of converging guide walls or chutes 10 and 11'are arranged to extend downwardlytowards a tobacco trough 12 along which runs a tobacco tape 13;

The roller 8 is arranged to be rotated by means of a chain 14 passing over a sprocket 15 on the shaft 16 of the roller 8, and a sprocket 17 on a shaft 18 which is arranged to rotate in the direction shown by the arrow. The shaft 8 may be the main drive shaft of the machine, or may be driven in any convenient and suitable way in synchronism with the other parts of the machine, so that the band 5 can be moved ,in timed relationship with Vthe carded roller 1, the picker roller 2, and winnower 3, andv other parts of the machine including the drive for the tape 13.

The shaft 19 of the roller 6 is journalled in bearings 20 which are movable along a slide 21 for the purpose of adjusting the tightness of the band 5'. An adjusting screw 22 is provided for this purpose.

A brush 23 is mounted beneath 'the lower run of the band 5 and arranged to engage the band in clean it.

Tobacco thrown upwardly and forwardly by the vanes 3 of the winnower falls on the upper surface of the band order to 5. The heavier particles of tobacco, which in general consist of pieces of tobacco stalk, tend to travel further than the lighter particles, due to their greater mass, andA therefore tend to pass over the wall 9 and to fall on the portion of the band between the rollers 6 and 7. The lighter particles, which are chiey shreds of tobacco leaf, mainly tend to fall short of the wall V9, or to strike it, and thus to fall on ,the part of the band between the rollers 7 and 8. Some of these lighter particles, however, travel further than others, possibly in some cases being carried by heavier pieces of stalk, and it is found that not only pieces of stalk but also shreds of tobacco leaf, suitable for incorporating in cigarettes, pass over the wall 9 and fall on the upwardly sloping part of the band between the rollers 6 and 7. In the known arrangement where a wall such as the wall 9 is relied upon to separate light from heavy particles, these shreds which were thus carried over the wall together with pieces of stalk would be segregated from the shreds which fell araasw 3 short ofthe wall, and would thus be excluded from the tobacco used. in making cigarettes.

It is found, however, that in the arrangement described and illustrated, when particles which include pieces of stalk and also shreds of tobacco leaf are thrown by the winnower varies 3 over the wall 9 so as to fall on to lthe band 5, pieces` of stalkv which strike the upwardly sloping length of the hand between the rollers 6 and 7 tend to bounce and slip on the relatively hard, smooth surface of the band, and to fall off the band to the left of the roller 6 as viewed in the drawing, while shreds of tobacco leaf which fall on the same part of the band tend to remain on it and to be carried forwardly and upwardly by the band, passingv beneath the wall 9. Lighter particles which fall directly on theV portion of the band between the rollers 7 and' 8 or which strike the face of the wall and drop down on to that portion of the band are, of course, also carried forwardly by the band.`

It is believed that this behaviour of the pieces of stalk is due to their relative hardness, and. to the relative hardness and smoothness of the surface of the band 5, as well as to the angle at which they strike the band, which de pends partly on the angle at which they are thrown by the winnower and partly on the angle to the horizontal at which the upwardly sloping part of the band is arranged between the rollers 6 and 7. As stated above, in example illustrated this angle is 25, which is found suitable for the purpose in this particular construction. In other constructions, for example, where the winnower is so arranged as to throw the tobacco at a different angle, it may be necessary to alter the angle at which the band is arranged to the horizontal. Also the position and height of the wall 9 may have to be adjusted to get the best results in any particular construction. In addition the position and arrangement of the band relative to the trough 12 and to the picker roller 2 and winnower 3 may require adjustment to obtain the best results in any particular construction.

The material used for the band 5, namely polyvinyl chloride, is found to have a sufciently hard, smooth surface for the present purpose but if other materials are used itis necessary to choose a material whose surface is hard and smooth enough to cause the pieces of stalk to bounce and slip on it, and' here again it may be necessary to arrange the band at a different angle from that chosen in the present example, namely to the horizontal. However, it would seern that in a construction made according to the drawing and having a band having a smooth surface of polyvinyl chloride only a very slight deviation of say 2 or 3 each way from 25 will y provide the desired result whereby the stalks will fall off the band whilst the softer acceptable tobacco particles will cling to and remain on the sloping surface.

The tobacco carried forwardly by the band 5 is discharged into the trough 12 and falls on to the tobacco tape 13, which carries it forwardly in the form of a stream. The particles, principally pieces of stalk, which fall from the band to the left of the roller 6 can be collected in a suitable receptacle or disposed of in any suitable and convenient way.

The use of the band 5 to intercept falling tobacco which has been thrown by the winnower has another advantage in addition to that already described.

In constructions previously proposed for winnowing tobacco, where the tobacco is thrown towards a wall `arranged to intercept the lighter particles, while heavier particles are segregated. solely by passing over thev upper edge of the wall, the particles intercepted by the wall fall downwardly directly into the trough of the cigarettemaking machine. Thus at any given instant during operation there is a quantity of tobacco which has left the winnower but has not yet reached the tobacco tape in the trough. In this earlier arrangement, if the machine is stopped, the equivalents of the roller 1, the picker 2, the winnower 3 and the tape 13 arc normally all stopped at the same time. All the tobacco which has left the winnower, however, must fall on the tobacco tape which is now stationary, and thus an excess of tobacco accumulates on the tobacco tape whenever the machine is stopped. This may and often does cause choking when the machine is restarted.

Where however the whole or the greater part of the tobacco thrown by the winnower is intercepted by the band 5, as in the present construction, only a relatively small quantity of tobacco, namely that which has already started to fall from the band 5, falls on to the tobacco tape 13 after the machine has stopped, because the band 5 can by the arrangement described above for driving the roller S in synchronism with the other parts of the machine, be arranged to stop simultaneously with these other parts. This will result in an excess of tobacco on the band 5, but this is more easily dealt with than an excess in the trough.

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

1. Tobacco feeding apparatus comprising a toothed conveyor for cut tobacco, means to pick tobacco from said conveyor, a winnowing device arranged to receive tobacco so picked and throw it upwardly and forwardly, a partition located to intercept some of the tobacco so thrown while permitting heavier particles to pass over it, and a second conveyor having a smooth, relatively hard surface disposed transversely of and extending beneath said partition, said second conveyor moving in a direction opposed to the forward direction of movement of the thrown tobacco, the rear part of said second conveyor being located in a position to intercept only tobacco particles thrown over said partition, whereby hard particles such as stalk are thrown so as to strike the said rear part and tend to rebound therefrom in a direction opposed to the direction of movement of said second conveyor, while softer particles striking said second conveyor surface tend to remain on it and to be carried forwardly by it.

2. Apparatus as claimed in claim 1 wherein the said rear part of the second conveyor slopes upwardly toward the said partition.

References Cited in the file of this patent UNITED STATES PATENTS 1,318,003 Wheeler Oct. 7, 1919 1,321,201 Young Nov. 11, 1919 1,903,931 Molins Apr. 18, 1933 1,907,575 Podmore May 9, 1933 2,515,778 Knowland July 18, 1950 FOREIGN PATENTS 599,877 Great Britain Mar. 23, 1948 650,076 Great Britain Feb. 14, 1951

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