US3030966A - Filler forming mechanism - Google Patents

Description

April 24, 1962' R. LANORE 3,030,966

FILLER FORMING MECHANISM Filed Dec. 11, 1957 5 Sheets-Sheet 1 Fb'g'l.

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April 24, 1962 R. LANORE FILLER FORMING MECHANISM 5 Sheets-Sheet 4 Filed Dec. 11, 1957 April 24, 1962 R. LANORE FILLER FORMING MECHANISM 5 Sheets-Sheet 5 Filed Dec. 11, 1957- INVENTOR waw Qfeiqbmlw 3/111) ATTORNEY United States Patent 3,030,966 FILLER FORMING MECHANISM Raymond Lanorc, Paris, France, assignor to Usines Decoufle S.A., Paris, France, a French company Filed Dec. 11, 1957, Ser. No. 702,104 Claims priority, application France Dec. 18, 1956 9 Claims. (Cl. 131-84) This invention concerns improvements in or relating to apparatus for forming a continuous tobacco filler, for example in a cigarette-making machine.

One difiiculty that arises in the formation of a continuous tobacco filler by known methods is the tendency for the filler to contain varying quantities of tobacco along its length. In continuous rod cigarette-making machines it is usual to shower cut tobacco on to a travelling conveyor so as to form a loose tobacco stream which is subsequently compressed laterally and enclosed in a continuous web of cigarette paper to form a continuous cigarette rod. The loose stream formed on the conveyor is usually irregular in that the quantity of tobacco varies from point to point along its length, and these irregularities are generally also found, to a greater or less extent, in the filler of the wrapped cigarette rod, in spite of various means which have been used to improve the uniformity of the tobacco filler before it is enclosed in the paper wrapper. The present invention is directed to the problem of forming a tobacco filler of improved uniformity.

For this purpose the present invention provides in a tobacco manipulating machine such as a cigarette-making machine, apparatus whereby a tobacco stream is fed lengthwise by an air pervious conveyor, and including a trimming device, located downstream from the zone wherein the formation of the tobacco stream is effected and completed, to remove surplus tobacco from the stream, and suction means to apply air pressure to the tobacco in the stream by drawing air through the stream and through the conveyor, while the latter is carrying the stream from the said zone toward the trimming device.

The invention also provides trimming means to remove surplus tobacco from a tobacco stream, comprising a pair of rotatable elements, extending from opposite sides of the stream toward each other and into the path of tobacco in the stream, to engage tobacco at a desired level and hold it controlled while a third movable element removes tobacco projecting beyond the edges of the rotatable elements, so as to complete the trimming operation.

A further feature of the invention is the provision of means whereby the trimmed filler is carried by the suction conveyor into engagement with a cigarette paper web to which the filler is to be transferred, so that the filler is engaged simultaneously by the suction conveyor and the paper web during its transfer to the latter.

The invention further provides means whereby the trimming device may be raised and lowered in order to change the distance of the discs from the conveyor band.

Apparatus in accordance with the invention, for forming a continuous tobacco filler in a cigarette-making machine, will now be described by way of example with reference to the accompanying drawings, in which:

FIGURE 1 is a sectional end elevation diagrammatically illustrating apparatus according to the invention;

FIGURE 2 is a sectional front elevation;

FIGURE 3 is a plan view of part of the apparatus shown in FIGURES 1 and 2;

FIGURE 4 is a sectional view taken along the line IVIV, FIGURE 2;

FIGURE 5 is a sectional view taken along the line V-V, FIGURE 2; and

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FIGURE 6 is a sectional view taken along the line VIVI, FIGURE 5. 7

Referring first to FIGURE 1, the apparatus comprises a hopper 1 for out tobacco, a conveyor belt 2 to support tobacco in the hopper, and a carded roller 3 towards which tobacco is urged by the conveyor belt 2, which move in the direction shown by the arrow. A brushing or levelling roller 4 is located adjacent the roller 3 and rotates in the same direction, as indicated by the arrows on the rollers 3 and 4. A picker roller 5 is arranged close to the roller 3 and is rotatable so as to pick tobacco from the carding of the roller 3 and distribute it on an endless conveyor belt 6. The conveyor 6 is arranged to move in the direction of the arrow at a speed of 4 feet per second.

Beyond the end of the upper run of the conveyor 6 is a passage 8 which extends along the whole width of the conveyor belt 6, see FIGURE 2. The passage 8 comprises opposed walls, spaced 10 mm. apart, whose opposed surfaces are slippery to reduce friction. These walls extend upwardly and their upper extremities are connected to a pair of side guides or walls which form a channel 9, as best seen in FIGURE 4. The walls of the channel 9 have slippery opposed surfaces, the upper parts of which are convergent (considered in a downward direction), each being at an angle of 10 to the vertical. A flat endless conveyor belt 10, which is 10 mm. wide, is arranged to move through the upper part of the channel 9, and passes wheels or rollers 11, 12 and 13 (see FIGURE 2) of which the roller 11 drives the belt. The conveyor belt 10 is perforated, being provided with small holes each of a diameter of 0.8 to 1.2 mm, About 40 such holes per square centimetre of the entire surface of the belt are provided.

The belt 10 is held within the channel 9 by the lower surfaces of a pair of opposed elements 14, which overhang the walls of the channel 9 by about 1 mm. on each side, thus forming shoulders which guide the belt through the channel.

The channel 9 and conveyor belt 16 are slightly inclined downwardly in the direction of movement of the band. This inclination may for example be at an angle of 6 to 10 to the horizontal.

A suction chamber 15 communicates with the perforated conveyor belt 10 by way of a narrow chamber 16 formed by the opposed elements 14. The chamber 15 further communicates with a pipe 17, FIGURES 1 and 2, which extends to the inlet of a fan (not shown) arranged to draw air through the pipe 17 from the chambers 15 and 15 and thus through the perforated conveyor belt 10.

The passage 8 extends downwardly below the conveyor belt 6, and communicates with a pipe 21 which extends to the output side of the fan referred to above, so that air is blown through the pipe 21 into and through the passage 8. As illustrated in FIGURE 2, the air sucked' through the conveyor 10 between the points marked 18 and 19 in the figure reaches the conveyor from the passage 8, while between the points marked 19 and 20 the air is drawn through the channel 9, whose opposed sides are extended downwardly by guide plates 22.

The arrangement of the fan, the pipe 17, and the suction chambers 15 and 16, is such that a negative pressure of about 800 to 900 mm. of water is maintained in the chamber 16.

A trimming device for trimming the tobacco filler is provided beneath the channel 9 at a position beyond the passage 8, that is, between the points marked 19 and 20 in FIGURE 2. The trimming device comprises a pair of peripherally chamfered discs 23 mounted on two rotating spindles 24 driven by pinions 25. The discs are arranged to be rotated in opposite directions as indicated in FIG- URE 3, with a peripheral speed slightly greater than the linear speed of the conveyor belt 10. The two discs 23 have their bottom surfaces disposed in a single plane parallel to the plane of the flat conveyor belt 10. Although in the drawings the discs are shown apparently in contact, their opposed edges are, at the point where they are closest to each other, separated by a distance of 0.1 to 0.2 mm.

Beneath the trimming device is a paddle-wheel device 26 for removing tobacco which is separated from the filler by the discs 23. This comprises a hub 27 provided with four radial blades 28, each about 8 mm. wide. The hub is mounted on the end of a spindle 29 which is arranged to rotate at high speed and is inclined to the direction of movement of the conveyor belt 10. The blades 28 are adjusted so that their extreme edges rub against the bottom surface of both the disc 23 at the region where the edges of the two discs approach closest to each other, and thus engage and remove tobacco which is beneath the discs, completing the separation of that tobacco from the tobacco that passes above the discs.

An endless conveyor 30 extends beneath the rotating paddle-wheel 26 to receive tobacco removed and thrown downwardly by the blades 28. The conveyor 30 is arranged to convey such tobacco towards, and deposit it upon, a further conveyor 31 (FIGURE 1) which in turn deposits the tobacco on the conveyor band 2, which returns it to the hopper 1.

Means are provided for adjusting the position of the trimming device, in order to alter the level at which tobacco is separated from the filler carried by the conveyor 10. A frame 32 (FIGURES and 6) supports bearings 33 for the spindles 24 of the discs 23, and also the bearing 34 for the shaft 29 of the paddle-wheel 26. The frame 32 has a slide 36 which is slidable in a guideway 136 in a stationary frame 38. A tapped member 37 is carried by the slide 36, and a screw 39 which extends through the frame 38 is threaded through the member 37 and can be rotated by a knob 40 in order to raise or lower the frame 32, and therefore the discs 23 and the paddlewheel 26. The latter can move up and down with the 1f'rsame 32 because its spindle 29 includes a universal joint In the construction illustrated, the minimum distance of the edges of the discs 23 from the conveyor belt is 9 mm., and this distance can if required be increased, by lowering the frame 32, by any suitable amount.

In practice it is found that this distance can be increased from 9 mm. to 12 mm. with satisfactory results. The minimum distance of 9 mm. is of course determined by the walls of the channel 9. If it is desired to position the discs 23 still closer to the conveyor 10, this can be done by making the channel less deep, or in other words by making the channel walls narrower.

Referring now to FIGURE 2, an endless conveyor belt 41 is arranged to carry a continuous web 42 of cigarettepaper through rod-forming mechanism, including a tongue 43, by which the tobacco filler is enclosed in the cigarettepaper web to form a continuous cigarette rod. The belt 41 and cigarette-paper web 42 extend beneath part of the conveyor 10, and move at the same speed as the conveyor 10 and in the same general direction, although in the construction shown, the belt 41 runs horizontally while the conveyor 10 is slightly inclined downwardly in its direction of movement.

The suction chamber 16 extends to the point marked 20, FIGURE 2, and beyond that point the conveyor 10 is no longer in communication with the source of suction. The paper web 42 is led in beneath the conveyor 10 just before the latter reaches the point 20, and is thus in a position to receive and support the tobacco filler when this is no longer held by suction against the conveyor 10. The spacing between the paper web 42 and the conveyor 10 is at no point greatly in excess of the depth of the tobacco filler, and is preferably approximately equal to the depth of the filler, so that the latter can be transferred from the conveyor to the paper without any substantial drop and thus with little disturbance.

A shoe 44- is arranged between the tongue 43 and the roller 11 and has an edge just clear of the conveyor 10 to prevent tobacco being carried around the roller 11 by the conveyor 10.

The belt 41 is supported in a trough 141 which shapes it and the paper web 42 into arcuate form in the usual way.

The operation of the apparatus is as follows:

Tobacco is fed from the hopper 1 by the carded roller 3, on which it forms a carpet or layer from which surplus tobacco is brushed back by the brushing roller 4. The picker roller 5, rotating at high speed, picks tobacco from the carding of the roller 3 and throws it on to the conveyor 6, which as stated above is moving at a speed of 4 feet per second. This speed is high relative to the peripheral speed of the carded roller 3, and the tobacco is thus spread or distributed over the conveyor 6 fairly sparsely and in a somewhat separated condition.

At the point 7, FIGURE 1, the conveyor 6 passes over a guide roller and, due to the speed of the band 6, the tobacco is projected towards the passage 8. The distance from the point 7 (that is, the end of the conveying surface of the conveyor 6) to the passage 8 is, in the example illustrated, about 6 inches.

The passage 8 is so arranged and dimensioned in relation to the suction fan and the various air conduits that a stream of air flows upwardly through the passage 8 at a velocity of 30 feet per second. As stated above, the opposed walls of the passage 8 are spaced 10 mm. apart. This arrangement, whereby air flows at a speed of 30 feet per second through a 10 mm. passage, is found to give good results. Both the air speed and the dimensions of the passage may be varied if desired, but in any such case it is found preferable that the relationship between the air speed in the passage, and the spacing between the passage walls, should be governed by the formula where V=velocity of air in feet per second, and T=the distance between the walls of the passage (or in other words the depth of the stream of air) in millimetres.

As mentioned above, the tobacco is distributed over the conveyor 6 in a somewhat separated conditionthat is to say, the individual shreds or particles of tobacco are to a considerable extent separated from one another by the picking operation and are distributed over the surface of the conveyor 6 in a similar condition owing to the high speed of the conveyor 6 relative to that of the carded roller 3.

These particles of tobacco, moving at a speed of 4 feet per second, are projected into the passage 8 and thus immediately subjected to the action of a stream of air moving upwardly through the passage at a speed of 30 feet per second. Thus successive particles of tobacco are suddenly and violently accelerated by the rapid upward current of air. This sudden acceleration greatly increases the separation of particles from one another, and tends to space individual particles apart from one another to a considerable extent, resulting in a rapid upward flow of separated particles most of which are spaced well apart from each other.

These particles are thus carried at high speed up into the channel 9 Where they accumulate on the underside of the conveyor 10, and on each other, to form a filler. The particles are held to the conveyor 10 by suction acting through the small holes in the conveyor.

Thus by the device disclosed a tobacco filler is built up of substantially uniform density. The expression substantially uniform density must not, however, be understood as meaning necessarily a density which is uniform throughout the depth of the filler. The forces acting on the particles of tobacco at different depths or levels of the tiller, as the latter is built up in the channel 9, may be affected by the changing quantity of tobacco held against the perforated conveyor, in such a way as to produce a greater density of tobacco at one level than at another. The density at any one level is, however, thought to be substantially the same alon the length of the filler (excluding any parts of the filler whose density may be deliberately increased by some means other than the impact of tobacco under the influence of the air stream).

The walls of the channel 9 being convergent (considered in a direction away from the conveyor tend to give some support to the filler in addition to that given by suction.

As stated above, the walls of the channel 9 are slippery, and consequently they offer low resistance to the tobacco filler formed in the channel 9. The effect, therefore, is that the filler is conveyed forward by the conveyor and subjected to the minimum of disturbance along its length.

Tobacco is fed to the passage 8 in suificient quantity, in relation to the speed of the conveyor 10, to enable a filler to be built up on the conveyor of greater depth than is required in the final filler. The filler so formed may vary in depth from point to point along its length, but its minimum depth should, as far as is practicable, be at least equal to the distance between the conveyor 10 and the discs 23 of the trimming device which removes excess tobacco and thereby trims the filler to a uniform depth. Since the width of the filler is controlled by the side walls of the channel 9, it will be seen that the filler after trimming, being of substantially uniform density along its length (in the sense explained above) and now having a substantially uniform cross-sectional size, is capable of being compressed to cigarette-rod size while maintaining to a very great extent the uniformity of its density. I

In the construction described, where a negative pressure of 800 to 9OQ mm. of water is maintained in the chamber 16, and where air is blown at a velocity of 30 feet per second upwardly through the passage 8 whose walls are 10 mm. apart, it is found that a filler of a particular type and moisture content can be formed on the conveyor 10 with a density equal to at least half the density required in the final filler-that is, when it has been compressed beneath the tongue 43 and enclosed in the paper web 42.

The amount of pressure exerted on the tobacco to compact it to at least half the final density will of course vary with the kind and condition of the tobacco being used. Accordingly such pressure will vary according to immediate needs.

The trimmed filler is carried past the point 20, FIG- URE 2, beyond which it is no longer held to the conveyor it by suction. By this time, however, it has been led over the paper web 42 which is moving at the same speed as the filler and is close enough to the conveyor 10 to receive the filler from the conveyor without the filler being subjected to any substantial drop or other disturbance. Thus the structure of the filler which has been formed and trimmed on the conveyor 10 is little disturbed during transfer to the paper web.

The final compression of the filler under the tongue 43, and its enclosure in the paper web 42 to form a continuous wrapped cigarette rod which is severed to produce individual cigarettes, follows conventional practice and need not be described.

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

1. In a continuous rod cigarette-making machine having a tobacco hopper, apparatus for forming a continuous tobacco filler, comprising an air-pervious conveyor arranged to move lengthwise, means to feed tobacco particles upwardly toward said conveyor, means, including a suction device located above said conveyor, to .cause air to flow upwardly through the said conveyor whereby the said tobacco is held on the underside of the conveyor and forms a filler thereon, a trimming device comprising a pair of cooperating rotating trimming discs disposed downstream from the zone wherein said filler is formed and beneath the conveyor and a rotatable element beneath the discs arranged in cooperation with the discs to trim the said filler to a desired cross-sectional size by removing therefrom surplus tobacco with projects beneath the discs, means disposed beneath said trimming device to receive surplus tobacco falling therefrom, and conveyor means to convey said surplus tobacco to the hopper.

2. In a continuous rod cigarette-making machine having a tobacco hopper, apparatus for forming a continuous cigarette rod, comprising an air-pervious conveyor arranged to move lengthwise, means to feed tobacco particles toward the underside of said conveyor to form a filler thereon, a suction chamber above said conveyor, means to draw air upwardly through said conveyor and said suction chamber to hold said tobacco filler against the conveyor, a trimming device comprising a pair of cooperating rotating discs disposed downstream from the zone wherein said filler is formed and beneath the conveyor and a rotatable element beneath the discs arranged in cooperation with the discs to trim the said filler to a desired cross-sectional size by removing therefrom surplus tobacco which projects beneath the discs while the filler is suctionally controlled by the conveyor, a further conveyor to convey a cigarette paper web beneath and past a part of said air pervious conveyor and said suction chamber at a position beyond the said trimming device and in the same general direction as that in which the said air pervious conveyor moves, said further conveyor being spaced from said band by a distance substantially equal to the depth of the trimmed filler, whereby the filler is engaged simultaneously by the said air pervious conveyor and the paper web.

3. Apparatus as claimed in claim 1, wherein the said rotatable element located beneath the said discs is arranged to rotate about an axis transverse to the axes of rotation of said discs, and positioned so as to engage the said discs while engaging tobacco projecting beyond the said discs.

4. Apparatus as claimed in claim 3, comprising a mounting for said discs and said rotatable element, means to raise or lower said mounting so as to raise or lower said discs and said rotatable element in unison, and drive means for said rotatable element, said drive means including a coupling which permits upward and downward movement of the rotatable member.

5. In a continuous rod cigarette-making machine, apparatus for producing a continuous tobacco filler, comprising tobacco feeding means to supply cut tobacco to form a continuous endwise-moving stream of tobacco, at trimming device downstream from the zone wherein the formation of the tobacco stream is effected and completed, said trimming device being arranged to separate and remove surplus tobacco from the stream and thereby produce a filler, a perforated conveyor to carry the stream of tobacco lengthwise from said zone towards the said trimming device, and suction means to apply air pressure to the tobacco in the said stream by drawing air through the stream and through the perforated conveyor, while the latter is carrying the stream from the said zone towards the trimming device, said trimming device being located at a point at which the stream remains under substantial compression resulting from the air pressure.

6. Apparatus for forming and trimming a tobacco stream in a tobacco manipulating machine, comprising conveyor means to carry a tobacco stream lengthwise, a tobacco removing element mounted for rotation and spaced from the conveyor means, a pair of opposed rotatable tobacco holding elements spaced from the conveyor means and extending toward each other across the conveyor means from opposite sides thereof and located between the conveyor means and the said tobacco removing element, tobacco feeding means arranged to supply tobacco in sufficient quantity for the formation of a tobacco stream of such depth that some of the tobacco in the stream extends beyond the said tobacco holding elements and is engageable by the said tobacco removing element, the said tobacco holding elements having edge portions which while moving in the same general direction as the stream engage the stream, the said tobacco removing element being arranged to move across said edge portions which are engaging the stream, so as to remove from the stream tobacco which projects beyond the said edge portions while tobacco between the conveyor means and the said tobacco holding elements is controlled by the latter.

7. Apparatus for forming and trimming a tobacco stream in a tobacco manipulating machine, comprising conveyor means to carry a tobacco stream lengthwise, side guides to maintain the stream within desired limits of width, means to supply tobacco in suificient quantity for the formation of a stream of greater mass per unit length than is required in the final product, trimming means to remove surplus tobacco from the stream, said trimming means comprising a pair of rotatable elements spaced from the conveyor, said elements extending from opposite sides of the stream toward each other and into the path of tobacco in the stream, and having tobacco engaging edges which while moving with the stream engage tobacco between them at a desired level and hold it controlled during the trimming operation, and a third movable element cooperating with the said pair of elements, and located at the opposite side of said elements from the conveyor means, to remove tobacco engaged by and projecting beyond the said edges so as to complete the trimming operation.

8. A tobacco manipulating machine for making tobacco smoking articles, comprising air pervious conveyor means to feed a tobacco filler lengthwise, guide means associated with said air pervious conveyor means to form therewith a confining channel for the tobacco filler, tobacco feeding means arranged to feed to said channel at a predetermined position a tobacco filler in the form of a stream which has been built up to a greater mass per unit length than that required in the final filler, means to draw air through the air pervious conveyor means and the said tobacco stream so fed thereon, to effect and maintain by air pressure a substantial compression of the said tobacco stream in the channel, and trimming means spaced apart from and downstream of the said position at which the said stream is fed to said channel, and being located at a point at which the stream remains under substantial compression resulting from the air pressure, to separate and remove surplus tobacco from the said tobacco stream and thereby to trim the stream to desired cross-sectional size while it is substantially compressed.

9. A tobacco manipulating machine as claimed in claim 8, in which said trimming means comprises a pair of relatively thin elements oppositely rotating about spaced axes and whose perimeters comprise tobacco engaging edges, a part of each element overlapping the air pervious conveyor means at a desired distance therefrom, the said elements being arranged for rotation in such directions that portions of their perimeters between the said axes move in the same general direction as the said tobacco stream and engage and hold tobacco between said portions, and a movable element cooperating with said pair of elements to engage and remove tobacco which is projecting beyond and held between the said elements, to complete the trimming operation.

References Cited in the file of this patent UNITED STATES PATENTS 7,226 Wales Mar. 26, 1850 140,693 Paul July 8, 1873 1,808,794 Stelzer June 9, 1931 2,660,178 Rault Nov. 24, 1953 FOREIGN PATENTS 431,456 Germany July 7, 1926 673,628 Germany Apr. 1, 1939 1,098,119 France Mar. 2, 1955 764,551 Great Britain Dec. 28, 1956

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