US2833290A - Machines for manipulating cut tobacco - Google Patents

Description

o. w. MOLINS MACHINES FOR MANIPULATING CUT TOBACCO Filed-Jan. 18. 1956 May 6, 1958 5 Sheets-Sheet 1 y 1958 D. w. MOLINS 2,833,290

MACHINES FOR MANIPULATING CUT TOBACCO Filed Jan. 18, 1956 s Sheets-Shet 2 pvvavm DESMoun M NouNS 5.) 33% M, Mad Wm TT Rwxs May 6, 1958 2,833,290

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MACHINES FOR MANIPULATING CUT TOBACCO Filed Jan. 18, 1956 5 Sheets-Sheet 5 Fig .5.

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United States Patent MACHINES FOR MANIPULATING CUT TOBACCO Desmond Walter Molins, Deptford, London, England,

assignor to Molins Machine Company Limited, London, England, a British company Application January. 18, 1956, Serial No'. 559,798

Claims priority, application'Great Britain January 28, 1955 Claims. (Cl. 131-409) veyor which'carries it as a continuous stream or filler through or towards devices which manipulate it to form it into a continuous tobacco rod which may eventually be enclosed in a continuous paper wrapper. The best known example of such a machine is the continuous rod cigarette making machine.

Cigarette making machines of the continuous rod type are provided with tobacco feeding apparatus in which a mass of cut tobacco is placed in a hopper and subjected to various brushing and combing operations and finally showered on to'a conveyor, where it forms a loose tobacco filler, and by means of which, or by a succeeding conveyor, it is formed into a tobacco rod or core which is afterwards wrapped in paper.

The aforesaid loose filler and the resulting rod are not as uniform in consistency as is desirable, and many attempts have been made to improve the-uniformity of distribution of the tobacco in the final rod. To a great extent this defective distribution in the tobacco filler is no doubt due to irregularities in the shower itself, but it is believed that it is also caused to a considerable extent by events taking place as the shower contacts with the conveyor on to which it falls. This conveyor always moves at a high speed, i. e. at least at a speed equal to a rod speed giving 1000 cigarettes per minute of 70 mm. cigarette length.

The shower is usually long and narrow in cross-section and the conveyor that receives the shower is often arranged horizontally so that considered in the direction of movement of the conveyor the tobacco falls at right angles thereto. It has long been realised that in such an arrangement, when the conveyor moves fast (as in modern high speed cigarette manufacture) a falling tobacco particle striking the fast-moving conveyor tends to rebound and, being unable to change its motion instantaneously to that of the conveyor, tends to fall back on to some part of the conveyor other than that on which it originally fell. This displacement of rebounding tobacco particles lengthwise of the conveyor is itself irregular and thus results in irregular distribution of tobacco along the length of thestream formed on the conveyor. Various proposals have been made, in an endeavour to overcome this difiiculty, for means to give the falling tobacco a component of movement in the direction of movement of the conveyor.

In a case such as that just referred to, the falling tobacco particles are, relatively to the conveyor, moving rearwardly at an acute angle to the conveyor surface. If the upper surface of the tobacco already on the condesired direction towards the said fast conveyor.

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Patented May 6, 1958 tend to pile up on or in front of such higher portions while the lower portions will be to some extent shielded by the high portions and thus not receive as much tobacco as they otherwise would. In this way the irregularity already existing (due to irregular bouncing of the tobacco or to any other cause) is aggravated. Even if the upper surface of'the tobacco is regular, however, there will almost certainly be shreds of particles projecting upwardly from the stream above the general level of the surface, which upstanding shreds will act, in the same way as described above with reference to high portions of the stream, to cause piling up of the falling tobacco at irregular intervals.

Mention has been made of irregularities in the shower itself. These may be caused by irregularities in the layer or .carpet of tobacco from which the tobacco showered on to the conveyor is picked. It is believed, however, that they may also in part be present in a case where tobacco, when picked from the carpet, is not thrown downwardly directly towards the conveyor but is thrown upwardly, for the purpose of winnowing it, and then drops on to the conveyor after stalk and other heavy particles have been taken out.

According to the present invention there is provided in a tobacco manipulating machine (e. g. a cigarette making machine of the continuous rod type) a fast conveyor to receive tobacco and carry it lengthwise as a stream at high speed (c. g. at or above the speed of the cigarette rod) means to discharge tobacco (e. g. from a hopper) in the form of a shower, a slow conveyor arranged to move lengthwise of the shower at a slower speed than that of the said, fast conveyor (e. g. at one third the speed of the fast conveyor) to intercept the showered tobacco, and transfer means to transfer tobacco from said slow conveyor to said fast conveyor in such manner that the move ment of the tobacco, as it reaches the said fast conveyor, has a substantial component in the same direction as the movement of the said fast conveyor. Preferably said component is so substantial that the tobacco reaching the fast conveyor is moving substantially at the speed of said conveyor.

The said transfer means may comprise picker mechanism to remove tobacco from an end of the said slow conveyor and impel it at the desired speed and in the Preferably the said fast conveyor is arranged at a lower level than the said slow conveyor. For example, it may be located beneath the slow conveyor, and may be arranged to run in the reverse direction to that of the slow conveyor. In the latter case, the direction of the tobacco will of course be reversed when it is transferred from the slow to the fast conveyor.

The transfer means may further comprise a toothed "conveyor, for example a carded roller, on to which tobacco is fed by the said slow conveyor and from which it as aforesaid on reaching the said fast conveyor.

the fast conveyor. In such a case, means is provided'to The said toothed conveyor may be arranged to move with a surface speed lower than that of the said slow' conveyor so that tobacco while being fed on to the toothed conveyor becomes packed into the teeth of the latter.

The said slow conveyor will of course be much more heavily loaded with tobacco than will the fast conveyor. To avoid forming an inconveniently deep stream, the slow conveyor is preferably made considerably wider than restrict the width of the path through which tobacco passes from the slow to the fast conveyor. Preferably such means comprises converging guide walls to guide tobacco as it is thrown towards the fast conveyor.

ltwilll be seen that where tobacco is showered on to a surface that moves lengthwise of the shower,,the slower that surface moves the less will be the displacement of tobacco. particles on it due to slipping and irregular bouncing as discussed above, and the less piling up will occur in front of upstanding tobacco shreds.

Moreover, where the shower itself is irregular (for whatever reason) the slower the surface moves the more likelihood there is of the unevenly showered tobacco be coming evenly distributed overthe surface.

Thus'the speed of the slow conveyor is preferably made as low as is reasonably practicable and convenient. This however is limited by the extent to which it is. permissible to load the slow conveyor while enabling the tobacco to be transferred to the fast conveyor in a satisfactory way.

The slow conveyor may be arranged to slope downwardly in its direction of movement, and in that case it will be seen that vertically falling tobacco particles will have a component of movement in the direction of the conveyor and equal to the speed of the latter, which will further reduce the tendency of the falling particles to slip or to rebound irregularly on the slow conveyor.

Apparatus in accordance with the invention will now be described by way of example with reference to the accompanying drawings, in which:

Figure 1 is a view looking at the front of a tobacco hopper of a cigarette making machine and showing 'the collector conveyor and associated parts.

Figure 2 is a plan of the collecting conveyor.

Figure 3 is a view of Figure l in the direction A and partly broken away on the line III--III.

Figure 4 is a diagram of the whole machine showin how the tobacco reaches the rod forming mechanism.

Figures 5 and 6 show slightly modified constructions.

Figure 7 is a diagram showing a modified arrangement of a conveyor belt shown in Figure 1.

Referring to Figure 1, tobacco is showered down inthe direction of the arrows by devices shown in Figure 3 and falls on a slow conveyor consisting of a collecting conveyor belt 2. a

In Figure 3, 3-is a combining roller in a hopper 4, and 5 is a picking roller which picks tobacco from the carding on the roller 3. The picking operation takes place i'na concave 6, and the tobacco is forthwith thrown upwards at an angle by a winnower 7. Stalks and other heavy pieces are thrown over the upper edge 9D of a wall or shield 9 fixed to a wall 8, and thus separated from the tobacco and collected.

The remaining tobacco partly slides down the shield 9, on to the belt2, whilesome just falls freely on the belt. The shield 9 is canted with respect, to the belt so that its bottom edge 9A runs obliquely across the belt from one end to the other. That is, thefar end, Figure 3, of the shield, corner 9B, is near one side of the belt while the near end, corner 9C, is near the other side of the belt. The disposition of the bottom of the shield is more clearly shown in Figure 2 where the lower part thereof is shown in section and the top edge in broken lines. Thus different portions along the length of the shower fall on different area-strips of the belt surface. If desired the part of the shield near the belt may be bent slightly to convex form.

The belt is about 4" wide whereas the width of the stream formed on the hopper tape of an ordinary cigarette machine is say 1"-1%" wide, assuming that a flat stream is being formed. This means that the belt 2-can run at about A to /3 of the speed of a'normal hopper tape and carry three to four times the tobacco per inch of length. With this substantial reduction of speed the disturbing effect of the contact between shower and C01- 2i lecting tape is very much reduced. The showered tobacco then forms a 4" wide carpet on the belt. The right-hand end, Figure 1, of the conveyor is near a toothed or pin roller 10 and to the left of this is a picker roller 11. Tobacco is pressed into the pin roller by a smooth roller 10A. The pins 11A of the roller 11 are canted backwards as considered in the direction of rotation and this helps the roller to pick the tobacco from the pin roller without appreciable breakage. The peripheral speed of the pin roller may be slightly less than the linear speed of the belt 2 so that there is a certain amount of packing action in the transfer of tobacco from belt to pin roller. A concave 12 surrounds the right-hand side of the pin roller and tobacco. is picked at the edge 12A of the concave in the usual way. The picked tobacco is thrown down a chute 13 on to a final conveyor 14. This conveyor, see Figure 3 is 1%" wide so its speed will be 3.2 times that of the belt 2. Because it is narrow relatively to the belt 2, the chute' 13 has converging side walls, see Figure 3. The picker roller runs at a higher speed and the tobacco is flung down the chute at a very high linear speed. It will be noted that the path of the shreds is at an angle (in the construction shown, 64)

to the conveyor surface and the speed of the shreds should preferably be such that if it is resolved into components parallel to the conveyor and at right angles thereto, the parallel component is substantially equal to the conveyor speed, so that there is no material tendency to slip on the conveyor, and particles which rebound will tend to return to the spot first struck. Further, any tendency for piling up in front of upstanding tobacco shreds is materially reduced. In this way transfer to the second conveyor is effected with a minimum of disturbance.

The conveyor 14 is shown sloping upwards in the direction of its movement, see Figure l, but this is merely incidental to the particular machine shown, for, as will be seen from Figure 4, the conveyor 14 has to raise the tobacco to a position where it can pass into a smooth passage 15, of the kind described in United States Patent No. 2,671,452, issued March 9, 1954, to D. W. Molins and F. F. Ruau. At. the bottom of the passage is a paper web 16 which carries thefiller through the rod forming, sealing, and cutting devices of the kind commonly used on continuous rod cigarette-making machines.

In Figure 5 the slow conveyor is marked 20 and a presser roller 21 presses the tobacco into a carded or pin roller 22 having a concave shield 23. The picker roller 24 beneath .the carded roller picks the tobacco therefrom and carries it around a concave 25 to discharge it on to a belt 26 with a substantial component of movement in thedirection of travel of the belt 26.

In Figure 6 the slow conveyor 30 feeds the tobacco to a pin roller 31 from which it is removed by a picker roller 32 which picks the tobacco against the edge of a short concave 33, the latter merging into a straight guide 34 The concave 33 is pivoted at 35 and the angle of the guide 34 can thus be adjusted, for example, the guide can be moved to the broken line position. The picked tobacco is discharged down the face of the guide near to the picker roller and reaches a belt 36 with a component of movement in the direction of movement of the belt,

which in this case is shown curling up in the manner customary with a cigarette tape as it enters the rod-forming devices. I e

In Figure 7, the conveyor belt 2, previously shown in Figure 1 as horizontal, is shown sloping downward in the direction of its movement. In this way the falling tobacco has a component of movement in the direction of movement of the conveyor and this helps to reduce the tendency of the falling particles to slip or rebound irregularly on reaching the belt 2.

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

1. A tobacco manipulating machine comprising a fast conveyor to receive tobacco and carry it lengthwise as a stream at high speed, means to discharge said tobacco in the form of a shower Whose horizontal cross-section is elongated in one direction, a slow conveyor arranged to move transversely of the shower in the direction of its elongation at a slower speed than that of the said fast conveyor to intercept the showered tobacco, and transfer means to transfer tobacco from said slow conveyor to said fast conveyor in such manner that the movement of the tobacco, as it reaches the said fast conveyor, has a substantial component in the same direction as the movement of the said fast conveyor.

2. A machine as claimed in claim 1 wherein the transfer means is arranged to give the transferred tobacco a component so substantial that the tobacco reaching the fast conveyor is moving in the same direction and substantially at the speed of said conveyor.

3. A machine as claimed in claim 1 wherein the transfer means comprises picker mechanism to remove tobacco from an end of the said slow conveyor and impel it at the desired speed and in the desired direction towards the said fast conveyor.

4. A machine as claimed in claim 1 wherein the fast conveyor is arranged at a lower level than the said slow conveyor.

5. A machine as claimed in claim 4 wherein the transfer means comprises a toothed conveyor on to which tobacco is fed by the said slow conveyor and from which it is picked and thrown down on to the said fast conveyor in such a direction and at such a speed as to give the tobacco particles the desired component of movement on reaching the said fast conveyor.

6. A machine as claimed in claim 5, wherein the toothed conveyor is arranged to move with a surface speed lower than that of the said slow conveyor so that tobacco while being fed on to the toothed conveyor becomes packed into the teeth of the latter.

7. A machine as claimed in claim 1 wherein the slow conveyor is at least twice the width of the fast conveyor and means is provided to reduce the width of the tobacco during transfer so that the wide stream on the first said conveyor is reduced to the width of the second said convey-or.

8. A machine as claimed in claim 1 wherein the slow conveyor is arranged to slope downwardly in the direction of its movement to reduce the tendency of the falling particles of tobacco to slip or rebound irregularly on said conveyor.

9. A machine as claimed in claim 1 comprising a winnower for throwing tobacco upwards and towards the slow conveyor to cause it to fall as a shower thereon and a wall for segregating heavy particles which are thrown further than the rest of the projected tobacco, said wall having its upper edge substantially parallel to the direction of movement of the slow conveyor and its lower edge canted across the width of said conveyor so that the width on to which the shower may fall increases gradually to a maximum at the delivery end.

10. A machine as claimed in claim 5 wherein tobacco picked from the toothed conveyor is guided by a wall in its movement toward the fast conveyor the angle of inclination of said wall to the fast conveyor being such that the desired component is secured by the combination of the picking speed, disposition of the picker, and the angularity of said wall.

References Cited in the file of this patent UNITED STATES PATENTS 1,876,012 Leary Sept. 6, 1932 2,224,294 Herrmann Dec. 10, 1940 FOREIGN PATENTS 1,246 Great Britain 1908 324,403 Great Britain Jan. 27, 1930 324,930 Great Britain Feb. 5, 1930 366,046 Great Britain Mar. 12, 1932 713,835 Great Britain Aug. 18, 1954

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