US3732871A

US3732871A - Method and apparatus for making cigarettes

Info

Publication number: US3732871A
Application number: US00030070A
Authority: US
Inventors: D Molins; F Labbe
Original assignee: Molins Machine Co Ltd
Current assignee: Molins Machine Co Ltd
Priority date: 1969-05-02
Filing date: 1970-04-20
Publication date: 1973-05-15
Anticipated expiration: 1990-05-15
Also published as: FR2046573A5; JPS49518B1; GB1314008A; DE2021289A1

Abstract

In making cigarettes, tobacco shorts are extracted from the tobacco supply after which the remaining tobacco is showered into an air stream onto a moving band to form a filler stream. The shorts are fed into the tobacco shower by means of a vibrating tray which serves to smooth the flow of shorts into the tobacco shower, the width of the stream of shorts in the shower having a predetermined width narrower than the total width of the shower so that the shorts occupy a predetermined level in the filler stream on the band.

Description

United States Patent 1 Molins et al.

[451 May 15, 1973 [54] METHOD AND APPARATUS FOR MAKING ClG-ARETTES [75] Inventors: Desmond Walter Molins, London, England; Francis A. M. Labbe, Neuilly-sur-Seine, France [73] Assignee: Molins Machine Company Limited,

London, England [22] Filed: Apr. 20, 1970 [21] Appl. No.: 30,070

[30] Foreign Application Priority Data May 2, 1969 Great Britain ..22,564/69 52 U.S.Cl ..131 s4c,131/10s,131/110 51 1m. (:1 ..A24c5/39 [58] FieldofSearch ..131/84B, 108,110;

[5 6] References Cited UNITED STATES PATENTS Howard ..l98/6O X 3,374,795 3/1968 Molins et al. ..l31/1 10 X 3,189,034 6/1965 Molins ..131/110 X 2,311,373 2/1943 Durning ..13l/108 2,280,056 4/1942 Broekhuysen ..131/108 UX 2,570,270 10/1951 Patterson 2,467,248 4/1949 Arelt 2,018,011 10/1935 Chandler .;...131/110 X.

FOREIGN PATENTS OR APPLICATIONS 111,559 3/1962 Pakistan...' ..13l/110 Primary Examiner-Joseph S. Reich A ttorney- Markva & Smith [57] ABSTRACT In making cigarettes, tobacco shorts are extracted from the tobacco supply after which the remaining tobacco is showered into an air stream onto a moving band to form a filler stream. The shorts are fed into the tobacco shower by means of a vibrating tray which serves to smooth the flow of shorts into the tobacco shower, the width of the stream of shorts in the shower having a predetermined width narrower than the total width of the shower so that the shorts occupy a predetermined level in the filler stream on the band.

9 Claims, 5 Drawing Figures PATENTEI] MAY 1 51973 SHEET 3 BF 3 uoqor 00000 I DOQOD QDODD 0000 METHOD AND APPARATUS FOR G CIGARETTES This invention is concerned with cigarette-making machines and particularly with machines of the type described originally in'U. S. Pat. No. 3,030,965 in the name of Labbe; that is to say machines in which the cigarette filler is built up by showering tobacco on to a suction band by means of air through a chimney extendingalong the band.

This invention is primarily concerned with the handling of tobacco shorts. These may for example be allowed to drop out from the bottom of the tobacco hopper of the making machine, though in principle the shorts may be extracted from the remainder of the tobacco in any convenient way.

According to the present invention, the shorts are fed by means of a vibrating tray which smooths the flow of shorts while feeding the shorts towards the shower as a stream of a predetermined width which is narrower than the stream of tobacco fed into the shower.

A preferred machine according to this invention is one having a chimney and a suction band, as already mentioned, and including also a trimmer which trims away part of the filler while the filler is still being compressed by suction. One possible machine layout including a chimney, a suction band and a trimmer is described for example in U. S. Pat. No. 3,030,966 in the name of Lanore and U.S. Pat. No. 3,088,467 in the name of Lanore.

The benefit of feeding the tobacco shorts on to the filler-carrying band arises primarily in the case of a machine with a suction band which carries the stream of tobacco forming the filler, and including a trimmer which trims away part of the stream to form the final filler. This is because the pressure in the tobacco stream is greatest adjacent to the suction band, and it is in the region of greatest pressure that the presence of shorts is least undesirable. Moreover, it is desirable to trim away good tobacco (which is then returned to the hopper of the machine) rather than shorts. The trimmer may for example remove 20 to 25 percent of the filler;

This invention is also applicable to a machine in which the tobacco is fed by gravity on to the band carrying the filler tobacco stream which forms the cigarette filler. After the stream has been built up on the band, it may for example be picked up by a suction wheel (or suction transfer band) and the trimming may be carried out while the tobacco stream is under suction pressure that is to say while it is being carried by the suction Wheel. In this case, the trimmer takes away tobacco from the side of the stream which previously lay against the band on which the filler was built up, and it will be appreciated that, in order to trim away tobacco and not the shorts layer, the shorts layer should in this case be deposited on the original band after the main body of tobacco; in other words, the original buildup of the filler stream is reversed so that the layer of shorts ends up adjacent to the suction wheel.

An example of a machine according to this invention is shown in the accompanying drawings. In these drawings:

FIG. l is a sectional view of part of the machine;

FIG. 2 is a section on the line 11-11 in FIG. 1;

FIG. 3 is a view from above the perforated block 21 shown in FIG. 1;

FIG. 4 is a view similar to FIG. 3 but showing an alternative block 21; and

FIG. 5 is a sectional view of a trimming device.

As shown in FIG. 1, the machine has a hopper 10 defined partly by a carded drum 11 at one side, a plate 12 at the other side, and a spiked drum 13 at the bottom. The carded drum 11 rotates in an anti-clockwise direction and carries from the hopper a carpet of tobacco which is transferred from the drum 11 by a picker roll 14 and then proceeds along a ramp with the aid of a further spiked roller 16. After leaving the ramp 15, the tobacco carpet passes round a suction drum l7 and enters the bottom end of a chimney defined by walls 18 and 19. Air then carries the tobacco as a shower up the chimney to a suction band 40 see FIG. 2. Heavy particles such as tobacco stem carry on past the suction drum 17 and are discharged down a ramp 20 to a suitable receptacle, as described for example in U. S. Pat. No. 3,030,965 in the name of Labbe.

' The air which carries the tobacco up the chimney enters mainly through a perforated block 21 (shown in plan view in FIG. 3), having arrived at the block 21 via a scroll 22 in a manner which will be further described. Some additional air also enters through a small inlet 23.

The drum 13 rotates in an anti-clockwise direction and carries downwards into a trough 24 any shorts which drop to the bottom of the hopper. The drum 13 also helps to compact the tobacco against the carded drum 11.

The bottom part of the trough 24 is pan-cylindrical so as to fit closely around a screw 25 which has a helical thread and rotates continuously so as to feed the shorts towards the left-hand end of the trough 24 as viewed in FIG. 2. Near its left-hand end the trough has an opening 26 through which the shorts drop so as to land on a vibrating tray 27.

The tray 27 is carried by flexible plates 28 and 29 (FIG. 1) and is vibrated by virtue of being connected by a plate 30 to a sleeve 31 which surrounds an eccentric 32 rotated by a shaft 33. The

plates

28 and 29 are inclined by a small angle to the vertical (e.g. approximately 15). Thus the shorts are conveyed along the tray, at right angles to the screw'25, towards the lefthand end of the tray as viewed in FIG. 1. The main part of the tray is horizontal so that the shorts move slowly along the tray and attain a fairly even level by the time they reach the left-hand end of the tray. At its left-hand end, the tray includes a part 34 which is inclined downwards by approximately 15 so as to accelerate the shorts. When the shortsreach the air stream by which they are carried up to the chimney, they are already travelling at a higher velocity that is to say, the stream of shorts is faster and less thick than on the horizontal part of the tray.

By way of example, the axis of the eccentric 32 may be offset from that of the shaft by approximately 1.5 mm. The speed of rotation of the shaft 33 may be up to 2,000 R.P.M. In a preferred arrangement, when the machine is started up, the shaft is driven by a motor at 1,000 R.P.M. (this being the slowest speed at which the shorts feed is really effective); then as the machine speeds up, a second drive on to the shaft 33 takes over and increases the speed of the shaft 33 in proportion to the speed of the machine as a whole, the top speed of the shaft 33 being 2,000 R.P.M. The reverse happens when the machine is slowed down; in other words, the shaft speed reduces until it reaches a speed of 1,000

R.P.M. at which it is maintained until the machine is altogether stopped.

The shorts are finally delivered into an upwardly extending channel defined, as viewed in FIG. 1, by walls 35 and 36 which extend up to the perforated block. Adjacent to the wall 36 (i.e. on the outside of the curve) the block 21 has a slot 21A through which the shorts can pass freely, the shorts flow being adjacent to the wall 36 as a result of centrifugal force. The shorts flow through the slot 21A joins the adjacent part of the to" bacco projected down the ramp 15, and the mixture of shorts and tobacco passes up the chimney approximately across an area shown in FIG. 2 as having a width W1. Air which carries up the shorts enters the shorts channel (i.e. between the walls 35 and 36) through the scroll 22, the air flow being induced by suction at the upper end of the chimney l8, 19.

The overall air flow is adjustable by varying the height of a flap 22A which can be swung up or down about an axis 22B.

The width of the shorts channel, measured in the direction of movement of the band 40, is W1, as shown in FIG. 2. W2 represents approximately the width of the tobacco flow which is substantially without shorts, while W1 plus W2 represents the total width of the car pet of tobacco which is carried into the space 37. Air flow through the perforated block 21 across the width W2 is fed to the block 21 from the scroll 22 via a channel defined by

walls

38 and 39.

As shown in FIG. 2, at the upper end of the chimney 18, 19 there is a suction band 40 which moves to the right as shown in FIG. 2 and on which a filler stream is deposited by the air flow up the chimney. The filler stream is then held against the porous band by suction as previously described, and is subsequently trimmed by means of a trimmer 100 located downstream of the chimney. The trimmer shown in FIG. removes part of the stream which is furthest from the band; that is to say, the layer of shorts proceeds past the trimmer. The trimmer comprises a pair of peripherally chamfered discs 123 mounted on two rotating spindles 124 driven by pinions 125. The discs are arranged to be rotated in opposite directions with a peripheral speed slightly greater than the linear speed of the suction band 40. The two discs 123 have their bottom surfaces disposed in a single plane parallel to the plane of the suction band 40. Beneath the trimmer is a paddle-wheel device 126 for removing tobacco which is separated from the filler by the discs 123. The blades 128 mounted on hub 127 are adjusted so that their extreme edges rub against the bottom of the two discs where the two discs are closest to each other, thus completing the separation of tobacco from the tobacco that passes above the discs.

Instead of being spiked, the drum 13 may be dimpled. For example, the dimples may be in the form of hemispherical recesses of approximately one-eighth inch diameter. In this case the drum 13 may lie in close contact with the upper edge of a stationary member 13A which may then act as a scraper which would help to prevent tobacco strands from passing downwards into the trough 24.

At the right-hand end of the tray 27 there is a chute 41 down which reconstituted tobacco may be fed to join the shorts feed. For example, the reconstituted tobacco may initially be in sheet form and may be cut up by means of a simple cutting machine working for example in the manner of a lawn mower or screw-fed mincing machine. Alternatively, the reconstituted tobacco may be in the form of extruded strands.

As an idea of scale, the total width of the chimney, (i.e. W1 W2) may be about 610 mm.

With the arrangement shown, the shower zone covering the width W1 will form an initial layer on the suction band including all the shorts conveyed by the vibrating tray. As an alternative the delivery of shorts, again across a width W1, may be moved slightly to the right as viewed in FIG. 2, so that the first layer showered on to the suction band at the top of the chimney is a thin layer of tobacco; this would then be followed by a layer of shorts plus tobacco, and then by the remaining tobacco. With this modified arrangement, the initial layer of tobacco on the band helps to prevent the shorts from being sucked through the band. An alternative block 21 to achieve this is shown in FIG. 4. The slot is displaced to the right so that the thin initial layer of tobacco is showered across width W3 before the shorts are showered on to the band across the width W1 through slot 21B. It will be appreciated that in order to achieve this, the and walls 35 and 36, and the downstream end of the tray, would be moved to the right so as to be appropriately aligned with the slot 21B to deliver the shorts to the shower over the desired zone; the upstream end of the tray can remain in the same position as shown in FIG. 2, the tray being inclined away from the illustrated position so as to deliver the shorts at the desired zone.

The fast-feeding tray may be vibrated by means of an electromagnetic device which may operate at a frequency equal to the resonant frequency of movement of the tray.

What we claim as our invention and desire to secure by Letters Patent is:

l. A method of making cigarettes in which tobacco is showered on to a moving band to form a filler stream thereon, including the steps of extracting shorts from the tobacco, feeding the tobacco in the form of a shower along a path leading to the band, feeding a.

stream of the extracted shorts towards said tobacco shower by means of a vibrating tray which smooths the flow of shorts, the width of said stream of shorts being narrower than that of the shower of tobacco, said stream of extracted shorts being fed along a first part of the tray at a relatively slow velocity as a relatively thick stream, being accelerated, and fed along the downstream end of said tray at a higher velocity as a thinner stream, discharging the thinner stream of shorts therefrom into a part of the tobacco shower, and showering the shorts on to the band together with said tobacco shower.

20 A method according to claim 1 in which the step of showering the tobacco and shorts on to the band comprises showering the tobacco and shorts by means of an air stream flowing towards the band.

3. A method according to claim 2 further comprising trimming away part of the cigarette filler stream formed on the moving band, said step of showering the shorts on to the band comprising showering the shorts at a position along the path of the moving band such that they occupy a level of the cigarette filler stream which remains after said part has been trimmed away.

4. A method of making cigarettes in which a stream of tobacco is showered onto a moving band by means of an air stream flowing towards the band to form a filler stream on the band, including the steps of extracting shorts from the tobacco before the tobacco is showered on to the band; feeding a stream of the extracted shorts part of the way towards the shower at a first relatively slow velocity by means of a vibrating tray which smooths the flow of shorts, the width of said stream of shorts being narrower than the stream of tobacco fed into the shower, and then feeding the shorts further towards the shower at a second, higher velocity; showering the shorts onto the band; and trimming away part of the filler stream formed on the moving band; said step of showering the shorts on to the band taking place at a position along the path of the moving band such that a thin layer of tobacco is showered on to the band before the shorts stream is showered on to the band, said shorts stream occupying a level in the filler stream which remains on the band after trimming.

5. A cigarette making machine in which tobacco is showered on to a moving band, including means for extracting tobacco shorts before the tobacco is showered; conveyor means for feeding the shorts towards and into a predetermined zone of the shower, said conveyor means having a first part comprising a vibrating tray which is arranged to smooth the flow of shorts while feeding the shorts towards the shower and to feed them at a relatively slow velocity, and a second part which is arranged to accelerate the shorts and feed them at a higher velocity; means for producing and directing an air stream towards said band by which the shorts and tobacco are showered on to the band; and a trimmer adapted to trim away part of the cigarette filler stream on the band, excluding the layer of shorts; said means for producing and directing an air stream towards said band being adapted to shower a thin layer of tobacco on to the band before the shorts stream is showered on to the band.

6. A cigarette making machine comprising a hopper for tobacco; means for delivering tobacco from the hopper and for feeding the tobacco along a path in the form of a shower on to a conveyor to form a cigarette filler stream; trimming means for trimming away part of the cigarette filler stream; means extracting shorts from the whole width of the hopper and means for feeding the shorts towards and into a predetermined zone of the shower along said path, whereby the shorts occupy a level in the cigarette filler stream on the conveyor which remains after said part of the cigarette filler stream has been trimmed away by the trimming means; the shorts feeding means comprising a vibrating tray arranged to vibrate in a predetermined direction and having an upstream portion set at an inclination to the direction of vibration whereby the shorts move along the upstream portion thereof as a relatively thick, slow-moving stream, and having a downstream portion which is inclined to the upstream portion and arranged so as to discharge the shorts therefrom into the shower as a thinner, faster-moving portion thereof.

7. A cigarette making machine in which tobacco is showered on to a moving band, including means for extracting tobacco shorts before the tobacco is showered; conveyor means for feeding the shorts towards and into a predetermined zone of the shower, said conveyor means having a first part comprising a vibrating tray which is arranged to smooth the flow of shorts while feeding the shorts towards the shower and to feed them at a relatively slow velocity, and a second part which is arranged to accelerate the shorts and feed them towards and into the shower at a higher velocity; said conveyor means being arranged to convey the shorts as a stream which is narrower than the width of tobacco showered on to the band and to feed the shorts in to the shower at a position such that a layer of tobacco is showered on to the band before the stream of shorts.

8. A machine according to claim 7 comprising a trimmer adapted to trim away part of the cigarette filler stream excluding the layerv of shorts.

9. A machine according to claim 7 in which said second part of said conveyor means comprises a downwardly inclined end portion to said vibrating tray.

Claims

1. A method of making cigarettes in which tobacco is showered on to a moving band to form a filler stream thereon, including the steps of extracting shorts from the tobacco, feeding the tobacco in the form of a shower along a path leading to the band, feeding a stream of the extracted shorts towards said tobacco shower by means of a vibrating tray which smooths the flow of shorts, the width of said stream of shorts being narrower than that of the shower of tobacco, said stream of extracted shorts being fed along a first part of the tray at a relatively slow velocity as a relatively thick stream, being accelerated, and fed along the downstream end of said tray at a higher velocity as a thinner stream, discharging the thinner stream of shorts therefrom into a part of the tobacco shower, and showering the shorts on to the band together with said tobacco shower.

2. A method according to claim 1 in which the step of showering the tobacco and shorts on to the band comprises showering the tobacco and shorts by means of an air stream flowing towards the band.

8. A machine according to claim 7 comprising a trimmer adapted to trim away part of the cigarette filler stream excluding the layer of shorts.