US2820463A - Manufacture of mouthpiece cigarettes - Google Patents

Description

Jan. 21, 1958 F b. WQMOLINS'; EI'AL MANUFACTURE OF MOUTHPIECE CIGARETTES Filed Nov. 14, 1955 AVVEA/TOZS Unite States Patent MANUFAQTURE or MOUTHPIECE CIGARETTES Desmond Walter Molins, Felix Frederic Ruau, and Norman Walter Jackson, Deptford, London, England, assignors to Molins Machine Company Limited, London, England, a British company Application November 14, 1955, Serial No. 546,642

(Ilaims priority, application Great Britain January 17, 1954 6 Claims. (Cl. 131--61) This invention concerns improvements in or relating tothe manufacture of mouthpiece cigarettes.

In one way of making mouthpiece cigarettes, an unwrapped stream of tobacco is fed forwardly and successive lengths are severed from its leading end. Each such severed length of tobacco is caused to be'spaced apart lengthwise from the unsevered stream, and a stub is inserted into each space so formed. Thus a continuous composite filler is formed, consisting of tobacco lengths and stubs in alternation. The composite filler is wrapped in a continuous cigarette-paper web to form acontinuous composite rod, which is severed at appropriate positions to form individual mouthpiece cigarettes'each of which contains a tobacco portion and a mouthpiece portion contained within a common wrapper. Usually the stubs inserted in the spaces are of double the length required in a cigarette, and are cut in half when the composite rod" is severed.

For convenience, the words tobacco length'or length of tobacco will be used herein' torefer not only to'a length rseparated from a tobacco stream, but also to the leading portion of the uncut stream itself, where the context: permits.

The Word'stub: where used herein is tobe understood 218'." including any portion (whether of the length required in a finished cigarette or double thatlength) of mouthpiece. material that is suitable for. incorporation in a mouthpiece cigarette, andmay consist of a piece of filteringmaterial, or of a hollow tube, or of any. other suitable piece of. material (including tobacco) that is different from the tobacco contained in the remainder of the cigarette; or it may consist of any combination of the foregoing. Well-lrnown examples of stubs are those often known-as filter tips or bunched wads of paper enclosed ina wrapper.

Informing a composite rod'as mentioned above, it'is sometimesdiificult to prevent the occurrence-of gaps or sparse portions between the ends of stubs and the ends of tobacco lengths. It also sometimes happens that the tobacco becomes denser at one end of a tobacco length than atthe-other, with the result that one of the twocigarettes produced from that length'isheavier than the other. These two problems are encountered particularly in a casewhere the stubs are insertedin spaces between tobacco lengths that are already lying on the continuous paper web that is to be Wrapped about the composite filler, because. in that case it is not always practicable or desirable to move the tobacco lengths bodily, relatively to the paper, in order to close up gaps.

A further problem arises in trying to ensure that the stubs are in the desired longitudinal positions in'the'composite'r'odthat is (where doubledcngth stubs areused, asis-usual), in positions such that they will bedivided into equal or nearly equal parts" when the rod is cut'to produce individual cigarettes. that the cigarettes should contain stubs thatare'reason ably consistent in 1 length.

Stubs are often made of folded- This is desirablewin orderv It. is .found,-, however, that a: stubinsertedat a-desired position -onth'e paper web -tends 2,820,463 Patented Jan. 21, 1958 "ice is secured around it. To counteract this tendency it hasbeen proposed, for example in British Patent No. 669,559}. in U. S. Patent No. 2,622,602, issued December 23, 1952,.- to D. W. Molins; and in U. S. Patent No. 2,667,877,.

issued February 2, 1954, to D. W. Molins,.to cause an.

element to move into the path of tobacco lengths and stubs, behind a stub, and to move forward faster than the tobacco and stubs and paper web so as to overtake and push forwardly a stub that is lagging behind its. de'-" It was also proposed to provide afurther sired position; element to advance tobacco behind the-stub, relatively to the paper web, in an endeavour to close up any gap' behind the stub.

In these prior proposals it was contemplated that the stub should initially be deposited on the paper web at the longitudinal position it was intended to occupy, relative to the paper web, in the composite rod, and should as far as practicable be held in or restored to that position.

According to the present invention there is provided, in the manufacture of mouthpiece cigarettes by inserting stubs between tobacco lengths on a paper web and subsequently wrapping and securing the paper around the pression tongue which by its compressing action on the' tobacco causes some of the tobacco to move rearwardly' relatively to the paper web.

The tongue referred to may be of the type generally used on continuous rod cigarette-making machines. A tongue of this type is generally arranged to slope downwardly over the cigarette paper web and to engage the upper surface of a tobacco filler passing beneath it, and

thereby compress it laterally, while the folding of the paper web about the tobacco is commencing. There is a tendency for such a tongue to force tobacco rearwardly, relatively to the paper web, and when such a tongue is used in the manufacture of mouthpiece cigarettes in the general manner referred to above, this rearward move ment of the tobacco has been found to be one of the principal causes of rearward lagging of stubs. Heretofore, as explained above, stubs have been initially dcpositecl on the paper web at the longitudinal positions they were intended to occupy in the composite rod, and

efforts have been made to correct orprevent any rearward displacement of the stubs from those positions.

In the method according to the present inventionas set'forth above, a stub may be initially deposited on the paper atapo'sition such that the back pressure of tobacco passing beneath the tongue will push the stub back to" substantially the desired longitudinal position it should ultimately occupy on the paper Web. In other words, allowance is made, when first placing the'stub on the paper, for the back pressure which the tobacco immediately preceding the stub will exert on it.

The method may also include engaging tobacco in the leading endportion of a tobacco length immediately following a stub, so as to control the tobacco so engaged and" thereby limit or control the backward movement of thestub relatively to' the paper web; Thismay be acc'ot'nplished by moving a tobacco-engaging element into'the" path of the. tobacco and. stubs so' as' to engage tobacco" behind a stub and thereafter to move forwardly, whileengaging, such tobacco; at substantially the speed otlie paper web, and then to Withdraw from said path. In this way the backward pressure exerted on the stub by the tobacco in front of it can be to some extent balanced by pressure of the tobacco behind the stub, and it is thought that when the stub is allowed to fioat freely between the tobacco lengths in this way, the pressure of the tobacco immediately in front of it can become more or less equal to the opposing pressure of the tobacco immediately following it, and that in consequence the density of these two portions of tobacco at opposite ends of the stub can become substantially the same.

Further according to the invention there is provided in apparatus for manufacturing mouthpiece cigarettes, apparatus for forming a continuous composite rod, comprising means to feed lengths of unwrapped tobacco lengthwise on a paper web with spaces between their ends, stubfeeding means to feed a stub into one of said spaces in advance of the position it is to occupy in the rod, means to retard said stub, and means to engage tobacco in the leading end portion of a tobacco length immediately following said stub so as to control the tobacco so engaged and thereby limit or control the retardation of the said stub. The last-named means may comprise a tobaccoengaging element arranged to move into the path of tobacco and stubs so as to engage tobacco behind a stub and thereafter to move forwardly at substantially the speed of the paper Web while engaging said tobacco.

The said stub-feeding means may comprise a rotatable member having one or more pusher elements on its periphery, and means to rotate said member at varying speeds such that a stub is pushed by a pusher element into a space between two tobacco lengths at a faster forward speed than the speed of said lengths, and that immediately thereafter the speed of rotation is reduced so that the pusher element ceases to push the stub at said faster speed. In this way, it is possible to feed a stub at a suitably fast speed without the necessity of withdrawing the pusher element, which can therefore be fixed on the rotatable member, for example a stub-wheel.

The variation of the speed of rotation of the rotatable member may be effected by means of a toothed driving element which rotates at constant speed and drives the rotatable member through an intermediate toothed element, the latter being arranged to be swung bodily to and fro about the axis of the said driving element so as to increase or decrease the speed of rotation of the said rotatable member. Preferably the said intermediate toothed member comprises a driving sprocket and a driven gear wheel rotatable therewith. The said driving element comprises a driving gear in mesh with the said driven gear wheel, and the drive is elfected by means of a chain passing around the said sprocket and a further sprocket on said rotatable member, the said driven gear wheel and driving sprocket being bodily swingable about the axis of the driving gear wheel. For example the driven gear wheel and driving sprocket may be mounted in a swinging member arranged to be swung about its pivot by a rotatable cam.

A method and apparatus according to the invention will now be described by way of example with reference to the accompanying drawing, which shows a side elevation, partly in section, with certain parts broken away, of apparatus by which a tobacco stream is fed lengthwise and severed at intervals, the cut lengths are spaced apart endwise, and stubs are inserted into the spaces between the tobacco lengths.

The apparatus illustrated comprises a tobacco tape 1 arranged to be moved beneath a hopper (not shown) through a trough 1a at varying speeds. A guide tube 2 and a further guide tube 3 are provided to receive a tobacco stream from the tape 1 and guide it on to a paper web 4 carried by a tape 5. Cutting mechanism is provided in order to cut the stream at intervals between the tubes 2 and 3.

The variation of the speed of the tape 1 is effected in any convenient way, preferably by means of the mechanism for this purpose described and shown in the complete specification and drawings of United States patent application Serial No. 461,163, file-d October 8, 1954, by N. W. Jackson. The speed variation is such that the speed of the tape is greatly reduced immediately after each cutting operation so as to allow a space to develop between the cut length, which is fed forwardly by the paper web, and the leading end of the uncut stream. Thereafter the speed of the tape 1 is increased to a speed such as to enable it to deliver the uncut filler on to the paper web at substantially the speed of the web 4, and the uncut filler is thus fed on to the paper web at that speed until the next cutting operation.

The cutting mechanism, which is constructed and operated as described in the provisional specification of United States patent application Serial No. 470,738, filed November 23, 1954, by N. W. Jackson, comprises a rotatable knife carrier 6 in which is clamped a thin, narrow knife blade 7 adapted to pass at high speed through the space between the tubes 2 and 3 on each revolution of the knife carrier 6.

A stub-wheel 23, arranged above the paper web 4, is mounted for rotation in the direction shown by the arrow. The stub-wheel 23 is formed as a disc having a concave rim as indicated at 25, and provided with pusherelements in the form of three projecting pusher-pins 26. Above the wheel 23 is a stub-feeding device (not shown) comprising a fluted drum by which double-length stubs are intermittently fed down in succession to a position to be engaged by each of the pins 26 in turn. The stubfeeding device is preferably the one described and shown in the complete specification and drawings of United States patent application Serial No. 480,403, D. W. Molins et al., filed January 1, 1955. An arcuate guide 27 is provided to guide stubs and prevent them from falling away from the rim of the wheel 23 until they reach a position at which they are to be deposited on the paper web 4.

The wheel 23 is driven by a chain 28 passing over a sprocket 29 fixed to the wheel. The chain 28 is driven by a driving sprocket 30, which has fixed to it a driven gear wheel 31 which meshes with a driving gear 32 fixed on a driving shaft 33 which rotates in the direction indicated by the arrow. The sprocket 30 and gear 31 are mounted in a bracket 34 which is freely pivoted about the shaft 33. Also mounted on the bracket 34 is a cam-following roller 35, which is capable of engaging a cam consisting of a rotatable cam 36. A spring 37 fixed on the bracket 34 urges the bracket about its pivot so as to press the cam-follower 35 against the rim of the cam 36. It should be noted here that the throw of the cam 36 is very small and its shape is very nearly that of a circle, and in the drawing has the appearance of acircle.

The chain 28 also passes over a guide sprocket 38 mounted on a pivoted arm 39 which is urged about its pivot in a clockwise direction by a spring 39a, so as to cause the chain to be kept tight.

The cam 36 is arranged to cause the bracket 34 to swing slightly to and fro about the shaft 33 three times during each revolution of the wheel 23. When the bracket 34 swings clockwise, as viewed in the figure, the sprocket 30, being carried towards the left in the figure, imparts a small increment to the speed of the chain 28 in excess of that given to the chain by rotation of the sprocket 30. On the return swing the speed of the chain is correspondingly slightly reduced. These swinging movements are so timed as to cause the wheel 23 to move at the faster speed as a pin 26 is approaching the paper web 4 and pushing a stub into a space between a cut tobacco length and the uncut tobacco stream. Immediately thereafter the return swing of the bracket 34 causes the wheel 23 to slow down so that the pin 26 moves with a. forward. speed approximately that of the. paper web.

The driven gear 31. rotates: at. two-thirds. the angular speed of the driving. gear 32,. and. at twice the angular speed of. the. sprocket. 29 and wheel 23. Thusthewheel' element. 40 performs thismovement three times. during.

each. revolution of the. stubawheel. 23, and is timed and arranged. to engage tobaccov immediately behind each stub insertedby. the, stub-wheel, and to. move at approximately the. speed of. the: paper web. 4 while. so. engaging tobacco. Toengage the, tobacco. it. passes through a slot 46 .ina tongue47,

The apparatus as. a. whole operates, as follows. The tape 1 carries a continuous stream. of, tobacco. and delivers it through the guide tubes 2 and 3 on to the paper web 4. Periodicallythe: speed ofthe tape 1 is temporarily greatly reducedand. just beforeeach such speed reduction the knife 7 is caused to pass between the two guide? tubesrso' as.to cut the stream. The-cut lengthzcontinues to move with the paper web,. while the uncut stream lags behind until the speed of the tape 1 is again increased: By-thattime a spacehas been developed between the cutlength andtheleadingend of the" uncut stream. A double-length stub is inserted into this space by a pusher pin 26 on the stub-wheel 23, which moves at varying speeds so that the stub is pushed into the space with a faster forward speed than that of the paper web and the tobacco carried thereby, and immediately thereafter the wheel slows down slightly so that the pusher pin moves with a forward speed approximately the same as the paper speed. As the tobacco and stubs pass beneath the tongue 47 the element 40 engages the tobacco immediately behind the stub and moves forwardly with it at approximately the speed of the paper web, thus controlling the tobacco speed and preventing it from lagging behind the stub or from being pushed backwardly by the stub.

Subsequently the paper web 4 is wrapped and secured about the tobacco and stubs to form a continuous composite rod, which is cut at appropriate intervals to produce mouthpiece cigarettes.

The cut-off mechanism (not shown) which may be of any suitable kind such as is used in continuous-rod cigarette-making machinery, is timed to cut through each stub and tobacco length in the composite rod, and the stubs and tobacco lengths are of double the length required in a finished cigarette.

The tongue 47 is similar to a compression tongue as frequently used on ordinary continuous rod cigarette-making machines, and as will be seen is of tapering form, and thus compresses the tobacco laterally as the tobacco passes beneath and through it. Due to this progressive lateral compression the tobacco is, as it passes through the tongue, squeezed or forced rearwardly so that some of it is caused to move rearwardly relatively to the paper web 4. Tobacco which is forced backwardly in this way exerts a backward pressure on the stub that immediately follows it, and forces the stub backwardly relatively to the paper web.

Accordingly the operation of the stub-wheel, and also of the cutting mechanism and the mechanism for varying the speed of the tape 1, is so timed in relation to the operation of the cut-01f mechanism that a stub is deposited by a pusher-element 26 on to the paper web 4 ahead of the position it is intended that it should occuPY longitudinally of the paper web, in the finished composite rod. A. suitable distance. in advance of. this.

position has. been. found to be to 2 mm. for a given weight and size of cigarette. The. purpose of this is to. allow for rearward. movement of. the stub by tobacco which is forced" rearwardly while passing. beneath. the tongue 47.

The extent of' setting discussed above will, ofv course vary with many different conditions, such as moisture, density of. compression, and. length. of tobacco sections, and accordingly each case would need to be adjusted independently to get the result contemplated here.

The distance by which a stub is pushed backward by the tobacco in front of-v it may also vary with different stubs, but it is found that a stub will in all cases, if permitted to do so, move back a certain minimum distance relatively to the paper Web, and the stub is therefore placed on to the paper initially at a position such as to allow for this minimum rearward movement.

The tobacco-engaging element'40 is arranged to engage tobacco behind a stub. with its serrated end 41 and to move forward at the speed of. the paper Web so as to prevent the tobacco immediately following the stub from being forced rearwardly by the tongue. This operation is so timed as. to check the rearward movement of the stub when it has moved. backwardly the minimum distance that has been allowed for. In other words, the stub isv thus prevented by the tobacco immediately behind it, from moving back beyond the predetermined longitudinal position it is intended to have relatively to the paper web. Inthis way the-backward pressure of tobacco preceding'a stub can bemore or less balanced by forward pressure of tobaccobehind the stub, and the density of the tobacco adjacent the opposite ends of the stub can be more or less equalized. Moreover, since the leading end portion of a tobcaco length is prevented from moving backwardly, as just described, while the remainder of that length is free to be forced or squeezed backwardly by the tongue, each tobacco length as a whole tends to be somewhat elongated, which of course is favourable to good abutment between tobacco and stubs.

The reason for pushing the stub into the space at a faster forward speed than that of the paper web is that for satisfactory results the space should be no longer than the stub, and it is thus necessary to push the stub in relatively fast to enable it to enter the space. If the stub wheel rotates with a constant peripheral speed faster than the paper web speed, the pushers must be retracted in some way immediately after insertion of the stubs in order to allow the latter to travel forward at the speed of the paper. With the present arrangement, however, the stub wheel rotates first at a suitable speed to push a stub into a space, and then at a reduced speed so that the pusher moves at approximately the same speed as the paper web. Thus the pushers need not be retractable, and the fixed pusher pins 26 are satisfactory.

It will be appreciated that when a stub is fed into a space between two tobacco lengths at a faster forward speed than the tobacco lengths, and in so doing the stub presses against the rear end of the tobacco length preceding it, that tobacco becomes somewhat compressed lengthwise. By allowing the tobacco to move rearwardly while passing beneath the tongue it is possible to allow the compressed tobacco to expand lengthwise and so become less dense than it would otherwise be.

It is found that by means of the method described, stubs can be located longitudinally in the composite rod at fairly even intervals and consequently mouthpiece cigarettes containing stubs of reasonably uniform length can be produced. Moreover it is possible by this method to secure good abutment between the stubs and the tobacco lengths, since the ends of two successive tobacco lengths both tend to be pressed against the ends of the stub be tween them while passing beneath the tongue. Further, by allowing tobacco to push the stub rearwardly to a certain extent, while holding the tobacco behind the stub against rearward movement, it is possible to obtain a good approach to equality in the two portions oftobacco which abut the stub.

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

1. In apparatus for manufacturing mouthpiece cigarettes, apparatus for forming a continuous composite rod, comprising means to feed lengths of unwrapped tobacco lengthwise on a paper web with spaces between their ends, stub-feeding means to feed a stub into one of said spaces in advance of the position it is to occupy in the rod, means to retard said stub, and means to engage tobacco in the leading end portion of a tobacco length immediately following said stub so as to control the tobacco so engaged and thereby limit or control the retardation of the said stub, said last named means comprising a tobacco-engaging element arranged to move into the path of tobacco and stubs so as to engage tobacco behind a stub and thereafter to move forwardly at substantially the speed of the paper web while engaging said tobacco.

2. Apparatus as claimed in claim 1, wherein the said stub-feeding means comprises a rotatable member having one or more pusher elements on its periphery, and means to rotate said member at cylically alternating peripheral speeds which are respectively greater than, and substantially the same as, the speed of the paper web, whereby a stub is pushed by a pusher element into a space between two tobacco lengths at a faster forward speed than the speed of said lengths, and immediately thereafter the speed of rotation is reduced so that the pusher element ceases to push the stub at said faster speed.

3. Apparatus as claimed in claim 2, wherein the means to rotate the said rotatable member comprises a toothed driving element which rotates at constant speed, an intermediate toothed element through which the driving element drives the. rotatable member, the intermediate toothed element, being arranged to be swung bodily to and fro about the axis of the said driving element so as to increase or decrease the speed of rotation of the said rotatable member.

4. Apparatus as claimed in claim 3, wherein said intermediate toothed element comprises a driving sprocket wheel and a driven gear wheel rotatable therewith.

5. Apparatus as claimed in claim 4, wherein the said driving element comprises a driving gear in mesh with the said driven gear wheel, a further sprocket on said rotatable member, and a chain passing around the said sprocket and said further sprocket to effect the drive, the said driven gear wheel and driving sprocket being bodily swingable about the axis of the driving gear wheel.

6. Apparatus as claimed in claim 5, comprising a swinging member in which the driven gear wheel and driving sprocket are mounted, and a rotatable cam to swing said swinging member about its pivot.

References Cited in the file of this patent UNITED STATES PATENTS 2,622,602 Molins Dec. 23, 1952 FOREIGN PATENTS 669,559 Great Britain Apr. 2, 1952 703,991 Great Britain Feb. 17. 1954

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