US3306305A

US3306305A - Manufacture of cigarettes

Info

Publication number: US3306305A
Application number: US221598A
Authority: US
Inventors: Molins Desmond Walter
Original assignee: Molins Machine Co Ltd
Current assignee: Molins Machine Co Ltd
Priority date: 1958-04-28
Filing date: 1962-09-05
Publication date: 1967-02-28
Anticipated expiration: 1984-02-28
Also published as: CH363924A; FR1222326A; GB922805A; NL108373C; NL238622A; DE1223284B

Description

Feb. 28, 1967 D. w. MOLINS MANUFACTURE OF CIGARETTES 2 Sheets-Sheet 1 Original Filed April 16, 1959 2 W W W J$rnonJ Walter Molina I 3 5r 'waDm cret G/dvdfi I 601730. ATTOK VEXS Feb. 28, 1967 D. w. MOLINS 3,306,305

MANUFACTURE OF C IGARETTES 3,306,305 MANUFACTURE OF CIGARETTES Desmond Walter Molins, Deptford, England, assignor to The Molins Organisation Limited, a company of Great Britain Continuation of application Ser. No. 806,909, Apr. 16,

1959. This application Sept. 5, 1962, Ser. No. 221,598 Claims priority, application Great Britain, Apr. 28, 1958, 13,409/58 5 Claims. (Cl. 131-61) This application is a continuation of my earlier filed copending application, Serial No. 806,909, filed April 16, 1959 and now abandoned.

This invention concerns improvements in or relating to the manufacture of tobacco articles such as cigarettes in-which a-tobacco filler is formed.

It has been proposed to form a tobacco filler, for example, in the manufacture of cigarettes, by supplying tobacco to one side of a perforated or porous moving conveyor band at whose other side suction is applied whereby the tobacco is held and laterally compressed on the conveyor band and forms a filler. It has also been proposed to form in this way a composite filler consisting of lengths of tobacco alternating with mouthpiece portions, by placing the latter on the conveyor band, at suitably spaced intervals, and supplying the tobacco so as to be received and held by the band in the spaces between the mouthpiece portions. For convenience the term tobacco filler stream is used herein to designate the rodlike elongated stream of tobacco (or of tobacco lengths alternating with mouthpiece portions) which is moved endwise by the conveyor toward a rod-forming mechanism in which it is enclosed in a wrapper to produce a continuous cigarette rod.

According to the present invention there is provided apparatus for forming a tobacco filler, comprising a perforated conveyor band, means to supply tobacco to the conveyor band, and means to apply suction to the conveyor band so as to hold the tobacco to the band, wherein at selected longitudinally spaced portions of the conveyor band the perforations in the band are so arranged as to cause the suction to have a different effect at the said selected positions from its effect at other positions.

For example, where the apparatus is to be used for forming a composite filler containing mouthpiece portions at spaced intervals alternating with cigarette tobacco filler portions the arrangement may be such that, at selected longitudinally spaced portions of the band the perforations are so located and arranged that they can be sub stantially wholly covered by mouthpiece portions placed on the band at the said positions for incorporation in the filler. Since the mouthpiece portions commonly used have convex surfaces, and are usually cylindrical, the perforations may at each of the said selected portions of the band be arranged in a single row centrally of the conveyor band-in other words, along that part of the band with which the curved surface of the mouthpiece portion will make contact.

Where it is desired to form a filler'which has denser and less dense portions along its length (e.g. in order to produce dense end cigarettes) selected longitudinally spaced portions of the band may be provided with perforations so arranged as to provide a greater total aperture per unit area of the band than do the perforations at other parts of the band, whereby the compressive effect of the suction on the tobacco at such selected parts is greater than at other parts of the band. In such a case the apparatus preferably comprises a trimming device to trim the filler by removing surplus tobacco so as to reduce the filler to a desired cross-sectional size, and the suction exerted on the tobacco in the filler may be such as to United States Patent ()fifice 3,306,305 Patented Feb. 28, 1967 compress it laterally to a substantial degreee.g. to a density at least half that required in the final tobacco product, such as a cigarette.

Where the conveyor band is frictionally driven by a driving roller or the like, it will be appreciated that slip may occur between the band and the roller, resulting in the band lagging behind its correct speed. This would result in the mouthpiece portions, or the denser portions of the filler, as the case may be, lagging behind their correct positions relatively to the cut-off mechanism which severs the continuous rod, formed from the filler, into cigarette lengths. Similarly creep may occurthat is, the band may advance beyond its correct speed, due for example to the drive rollers having a diameter slightly too large.

To counteract these tendencies, a detector device may be provided to register with those parts of the conveyor band on which mouthpiece portions, or denser tobacco portions, are to be carried or formed as the case may be, the said device being arranged to detect incorrect positioning of the said selected longitudinally spaced parts of the band, and means responsive to said detector device to vary the speed of the driving means for the band so as to correct the said positioning. For example, the detector device may comprise a photo-electric cell responsive only to light directed through perforations in the said selected parts of the band, which perforations are of such a nature that they pass more light to the said cell than do perforations in other parts of the band, and a shutter arranged to move across the band and having an aperture which periodically registers with the said cell and with a part of the band just adjacent one of the said selected parts it the band is correctly positioned.

Further according to the present invention there is provided a conveyor band for a continuous rod cigarettemaking machine,v provided with perforations along the whole of its length to enable air to be drawn therethrough for the purpose of suctionally holding a tobacco filler to the band, wherein over the greater part of the band the perforations are provided across substantially the width of the band, while at selected longitudinally spaced parts of the band the perforations are disposed only centrally of the width of the band in such a manner that they can be substantially wholly covered by cylindrical mouthpiece portions. 7

Still further according to the present invention there is provided a conveyor band for a continuous rod cigarette-making machine, provided with perforations along the whole of its length to enable air to be drawn therethrough for the purpose of suctionally holding a tobacco filler to the band, wherein selected longitudinally spaced portions of the band are provided with perfora tions so arranged as to provide a greater total aperture per unit area of the band than do the perforations at other parts of the band, whereby the compressive eflFect of suction on tobacco held to said selected portions of the band can be greater than at other parts of the band.

The expression mouthpiece portion as used herein shall be understood as meaning a length of material (other than the tobacco forming the main part of the cigarette) which can suitably be incorporated in a mouthpiece cigarette and through which smoke can pass, for example to filter it.

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 front view of part of a cigarette-making machine,

FIGURE 2 shows part of a perforated conveyor band, the View being taken in the direction of the arrow II, FIGURE 1, and shows a detector device and means to vary the drive of the band,

FIGURE 3 shows a detail of FIGURE 2,

FIGURES 4, and 6 respectively show portions of conveyor bands and illustrate three different arrangements of perforations in the bands.

Referring first to FIGURE 1, a flat endless metal conveyor band 1 passes over a driving roller 2 and a guide roller 3. The band is perforated so as to permit air which is directed upwardly through a narrow passage 4 to be drawn through the band into a suction chamber 5. The passage 4 has end walls 6 and 7.

Suitable suction devices are provided to cause air to flow upwardly through the passage 4 and through the band 1, and tobacco-feeding means, not shown, are provided to feed tobacco into the passage in excess of that required for the finished product, in such a way that the tobacco is conveyed by the air current up to the band 1 so as to form a filler on the lower run of the band, which moves in the direction indicated by the arrow. The suction devices and tobacco-feeding means may be substantially as disclosed in United States Patent No. 3,030,965 granted April 24, 1962.

A further suction chamber is located alongside the passage 4 and communicates with the latter by a grill 8, so as to withdraw a proportion of the air from the passage. The purpose of this arrangement, which may be as disclosed in United States Patent No. 3,019,793, is to enable air to be drawn into and through the passage 4 at a higher velocity than would be practicable if all the air had to pass through the band 1 and the tobacco thereon.

The suction devices are arranged so that a suctional pressure is exerted through the perforations in the band 1 on the tobacco which builds up on the band as a filler, such as to compress the tobacco filler to a density at least half (for example two-thirds) the density required in the final wra ed cigarette rod. As will be explained later, by means of one of the constructions to be described the density to which the tobacco is compressed may be locally increased at selected spaced parts of the band.

Beyond the wall 7 of the passage 4 is a trimming device comprising a pair of cooperating rotating discs, one of which is shown at 9, FIGURE 1, and which are arranged to trim the tobacco filler to a desired cross-sectional size by removing surplus tobacco.

Beyond the trimming device the conveyor band 1 extends over a cigarette-paper web 10 carried by a tape 11 through a trough 12 which shapes the tape and paper web to a cross-section of gradually increasing curvature. The suction chamber 5 extends over the paper web 11 so that the tobacco filler formed in the passage 4 and trimmed by the discs 9 is carried by the band 1 over the paper web and into engagement with the latter before the suction is cut off. Thus at the point where the filler is transferred on to the paper, the filler is gripped between the paper and the band 1.

In the left portion of FIG. 1, immediately beyond the roller 2 are provided compressing and shaping devices for the filler, including a compression tongue, and folding devices for folding the paper web 11 about the filler to form a continuous wrapped cigarette rod, all as disclosed in United States Patent No. 3,030,965.

To the right of the wall 6, FIGURE 1, is provided a stub-feeding device by which double-length mouthpiece portions may be fed to the band 1 at suitable spaced intervals so that a composite filler (consisting of mouthpiece portions and tobacco portions in alternation) may be formed on the band. This device includes a wheel 13 provided on its periphery with pushers 14, and an intermittently rotatable fluted drum 15 each of whose flutes accommodates a double-length mouthpiece portion. As the wheel 13 rotates, in timed relationship with the drum 15, each pusher 14 in succession passes through a flute and pushes a mouthpiece portion out of the flute, over an arcuate guide 16, towards the band 1 on which it is held by suction. A guide plate 17 is soltted as shown to allow the pushers to pass through it. Thus the mouthpiece portions are placed on selected longitudinally spaced parts of the band 1 before the band enters the passage to receive tobacco. The plugs are wrapped and have a diameter such that they will not be engaged by the trimming knives 9 as they pass the same.

It is desirable that the band while passing through the passage 4 should receive tobacco only at those parts of its surface which are between the spaced mouthpiece portions. To assist in this, the band 1 is provided with perforations so arranged as to have a different effect at the selected parts where the mouthpiece portions are deposited, than at other parts. As illustrated in FIGURE 4, the holes 18 in those parts of the band which are intended to receive tobacco are small and extend over the greater part of the width of the band. These holes 18 may be from 0.026 to 0.028 inches in diameter and may number 700 holes to the square inch of band. The selected parts of the band where mouthpiece portions are to be deposited, however, are provided with larger holes 19, arranged in single rows centrally of the band, so that the holes 19 in each row will be substantially wholly covered by that part of the cylindrical surface of a mouthpiece portion which makes contact with the conveyor band 1. Thus at those selected parts, suction is exerted only through the holes 19 which are substantially wholly masked by mouthpiece portions, so that there is little, if any, risk of tobacco being drawn by suction on to a part of the band on which a mouthpiece portion has been placed. This reduces the possibility of shreds of tobacco becoming trapped between the mouthpiece portions and the paper web 11 when the latter is wrapped around the filler.

FIGURE 5 diagrammatically illustrates another arrangement in which spaced selected parts of the band 1 are provided with groups of relatively large holes, extending substantially the full width of the band, and so dimensioned and arranged as to provide a greater total aperture per unit area of the band at a selected part than do the holes '18 at other parts of the band. For this purpose the holes 20 should be made as large as is practicable without being large enough to allow tobacco shreds to pass through the holes or become lodged in them.

The purpose of this arrangement is to increase the compressive effect on the tobacco of the suction exerted through the perforated band at these selected parts, and thereby cause the tobacco at those parts of the band to become more highly compressed by suction than the tobacco at intermediate parts. As a result, the tobacco filler is formed with denser and less dense portions, and when the filler is trimmed to the desired cross-section, there will be a greater quantity of tobacco at the said selected parts than elsewhere. The denser portions are so spaced and located that when the wrapped cigarette rod is severed to form cigarettes, it will be severed through the denser portions and thus dense end cigarettes will be produced.

If it is desired to form a composite filler of tobacco and mouthpiece portions with denser tobacco adjacent the mouthpiece portions than elsewhere, the arrangements of holes diagrammatically illustrated in FIGURES 4 and 5 respectively could be suitably combined. Thus the parts of the band which are to receive mouthpiece portions may be provided with central rows of holes 19, while parts of the band immediately adjacent the ends of these rows may be provided with holes such as the holes 20', larger than the holes 18 provided in the remaining tobacco-receiving parts of the band. Moreover, groups of holes such as the holes 20 may be provided midway between the spaced rows of holes 19 in order to produce denser tobacco portions at those ends of the cigarettes which are remote from the mouthpiece ends.

It will also be understood that if desired the holes provided in parts of the band where denser portions of the filler are required may be suitably graduated so as to permit a gradual variation in density of the filler. For

example a group of holes such as the holes 20 could vary in size, with the largest holes in the mid-portion of the group, the remaining holes becoming gradually smaller as they extend away from the mid-portion in both directions lengthwise of the band.

It will he appreciated that in all cases the selected parts of the band at which rows of holes 19 or groups of holes such as 20 are provided, are spaced apart lengthwise of the band by a suitable distance according to the length of cigarette to be made, in order that the continuous wrapped rod shall be cut at the appropriate positions, that is, through the mouthpiece portions or through the denser tobacco portions, or both.

In order to ensure that these selected parts of the band are maintained in correct position relatively to the cut-off mechanism of the machine, so that the rod may be severed correctly through the mouthpiece portions and dense tobacco portions, and also relatively to the wheel 13 and associated parts for feeding the mouthpiece portions to the band, detector devices are provided to check the longitudinal position of the band.

Since the band is frictionally driven by the roller 2, slip may occur between the band and the driving roller, with the result that the selected parts of the band lag behind their proper positions. On the other hand, creep of the band may occurthat is, the band may advance beyond its correct position, due for example to slight errors in manufacture of the drive roller resulting in a slightly excessive diameter, or possibly caused by tobacco fragments adhering to the drive roller and so increasing its eifective diameter. Either of these occurrences may in time cause incorrect positioning of the selected parts of the band.

FIGURE 2 illustrates diagrammatically an optical detecting device for detecting errors of position due to the band lagging behind its correct position, for example by slipping.

A light source 21 (see FIGURE 1) is located beneath the upper run of the band 1 in register with a light-sensitive cell 22 located above the band. A disc 23 constituting a shutter is rotatably mounted on a spindle 24 and extends between the band 1 and the cell 22. The disc has a small aperture 25, see FIGURE 3. The disc is rotated in timed relationship with the drive roller 2 by means of a belt 26 and pulleys 27 and 28 from a shaft 29 through bevel gears 30 and 31. The shaft 29 is arranged to drive the roller 2 through differential gearing as will shortly be explained, and the driving connection between the shaft 29 and the disc shutter 23 is such that the aperture 25 in the disc should (if the band 1 is correctly timed) register with holes in the first transverse row of holes 18 immediately behind the last hole 19 of a central row. In FIG- URE 2 the area of the band which is normally scanned by the cell 2 2 through the aperture 25 is indicated by the reference A.

Light passing from the light source 21 through the small holes 118 in the band is insufficient to energise the cell 22. If, however, the band is lagging behind its correct position, the aperture 25 will register with a hole 19, which passes enough light to energise the cell 22 and cause a current, amplified by an amplifier 32, to operate a relay 33 so as to close a contact 35 and thereby energise a solenoid 34. The solenoid operates a pawl 36 to turn a ratchet wheel 37 mounted on a shaft 38, which also carries a worm 39. The worm 39 meshes with a wormwheel 40 which constitutes a carrier for planet idler wheels 41 of a differential gear through which the roller 2 is driven,

as mentioned above. Thus operation of the solenoid 34 causes the planet carrier to turn and thereby momentarily speeds up the drive roller 2, thereby advancing the band 1 to correct its positioning.

A similar device is provided for the purpose of detecting creep or advance of the band beyond its correct position. The area scanned by this further device is indicated in FIGURE 2 by the reference B, and the device, which includes a light-sensitive cell 22a and a disc 23a (corresponding respectively to the cell 22 and disc 23) which are shown in dot and dash lines in FIGURE 2, operates to turn a ratchet wheel 37a so as to rotate the shaft 38 in the opposite direction to that in which it is turned by the pawl 36 and ratchet wheel 37. Accordingly, if a hole 19 registers with the shutter aperture, instead of holes 18 in the area B, the detector device is actuated in the same way as has been described in connection with the area A, and the drive roller is retarded.

The pawl 36, and the corresponding pawl associated with the ratchet wheel 37a, are of course positioned clear of their respective ratchet wheels when they are inoperative.

Similar detecting arrangements may be provided in a case where holes such as 20, FIGURE 5, are provided at the selected spaced parts of the band.

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

1. Apparatus for forming a tobacco filler, comprising an elongated conveyor, means to supply tobacco to the conveyor, means to apply suction to the conveyor, the conveyor being air permeable along the whole of its length whereby suction is applied to the tobacco to hold it to the conveyor, and a trimming device to separate and remove tobacco from the tobacco filler to reduce it to a desired cross-sectional size while itis suctionally held to the conveyor, the said conveyor being so constructed that spaced portions along the length thereof are more air permeable than the conveyor portions therebetween, whereby greater suctio-nal compression is exerted on the tobacco at said spaced portions than on tobacco at the said other parts of the conveyor so that after trimming the filler will contain more tobacco per unit length at the said spaced portions than at the said other parts, the said spaced portions being so spaced apart along the length of the conveyor as to register with portions of the tobacco filler which will ultimately be severed to produce cigarettes.

2. Apparatus as claimed in claim 1, wherein the conveyor comprises an impervious material provided with apertures to render it air permeable, said apertures communicating with the said means to apply suction and being so dimensioned and distributed as to provide a greater total aperture per unit area of the conveyor surface at the said spaced portions than do the apertures in the conveyor portions therebetween.

3. Apparatus for forming a tobacco filler consisting of tobacco sections alternating with mouthpiece portions, said apparatus comprising an air permeable conveyor made of impervious material and provided with apertures to make it air permeable, suction means acting through the apertures in the conveyor, means to supply to the conveyor at spaced. positions therealong mouthpiece por tions of substantially cylindrical shape such that their cylindrical surfaces make contact with only a narrow area of the conveyor surface centrally disposed therealong, and means to supply tobacco to the conveyor between the mouthpiece portions, the said conveyor being so constructed that the apertures at those positions along the conveyor to which the mouthpiece portions are applied are confined solely to those narrow areas with which the mouthpiece portions make contact, whereby the apertures at those positions are substantially wholly covered by the mouthpiece portions and the effect of suction at those positions is confined substantially wholly to the mouthpiece portions.

4. Apparatus as claimed in claim 3, wherein the tobacco receiving parts of the conveyor which are between the positions at which mouthpiece portions are received are provided adjacent said positions with groups of apertures so dimensioned and distributed as to provide a greater total aperture per unit area of the conveyor surface than do the remaining apertures in said parts, whereby greater suctional pressure is exerted on tobacco adjacent the mouthpiece portions than on other tobacco.

5. In a continuous rod cigarette-making machine, apparatus for producing cigarettes having dense ends comprising a conveyor for moving an elongated tobacco filler stream in the direction of its length and in a predetermined path, a trimming device positioned adjacent said path at a distance from said conveyor which is less than the maximum depth of said filler stream, means operating on said filler stream upstream of said trimming device to compress said filler stream against said conveyor at spaced positions along its length to a depth less than the depth of said filler stream existing between said positions, whereby the operation of said trimming device will leave more tobacco per unit length at said position, than between said positions, rod forming means compressing the trimmed filler stream to substantially uniform cross-section to form a continuous cigarette rod, whereby said rod may be severed at positions corresponding to said firstnamed positions to form cigarettes having a greater den- 2 sity of filler at the severed end than at the intermediate points.

References Cited by the Examiner UNITED STATES PATENTS 6/1931 Stelzer (II) 131-84 6/1931 Stelzer (I) 13184 10/1934 Podmore 13161 6/1939 Edwards 13194 10/1939 Bronader.

7/1941 Shoults et al. 250219.1 7/1942 Stein 13161 7/1947 Davidson 13161 5/1950 Enebeck 221-211 5/1960 Lanore 131-84 FOREIGN PATENTS 10/1931 Germany. 12/1956 Great Britain.

SAMUEL KOREN, Primary Examiner.

Claims

5. IN A CONTINUOUS ROD CIGARETTE-MAKING MACHINE, APPARATUS FOR PRODUCING CIGARETTES HAVING DENSE ENDS COMPRISING A CONVEYOR FOR MOVING AN ELONGATED TOBACCO FILLER STREAM IN THE DIRECTION OF ITS LENGTH AND IN A PREDETERMINED PATH, A TRIMMING DEVICE POSITIONED ADJACENT SAID PATH AT A DISTANCE FROM SAID CONVEYOR WHICH IS LESS THAN THE MAXIMUM DEPTH OF SAID FILLER STREAM, MEANS OPERATING ON SAID FILLER STREAM UPSTREAM OF SAID TRIMMING DEVICE TO COMPRESS SAID FILLER STREAM AGAINST SAID CONVEYOR AT SPACED POSITIONS ALONG ITS LENGTH TO A DEPTH LESS THAN THE DEPTH OF SAID FILLER STREAM EXISTING BETWEEN SAID POSITIONS, WHEREBY THE OPERATION OF SAID TRIMMING DEVICE WILL LEAVE MORE TOBACCO PER UNIT LENGTH AT SAID POSITION, THAN BETWEEN SAID POSITIONS, ROD FORMING MEANS COMPRESSING THE TRIMMED FILLER STREAM TO SUBSTANTIALLY UNIFORM CROSS-SECTION TO FORM A CONTINUOUS CIGARETTE ROD, WHEREBY SAID ROD MAY BE SEVERED AT POSITIONS CORRESPONDING TO SAID FIRSTNAMED POSITIONS TO FORM CIGARETTES HAVING A GREATER DENSITY OF FILLER AT THE SEVERED END THAN AT THE INTERMEDIATE POINTS.