A method of producing cheroots and similar tobacco articles and an apparatus for preparing wrappers by this method

Abstract

 In the production of cheroots and similar tobacco articles with a wrapper (3) of natural tobacco relieved of central rib portions but containing parts of side ribs (13), the said side ribs are subjected to a flattening process, at least in the end flap of the wrapper, by squeezing between a hard (11) and a comparatively soft (4,11) surface so as to prevent the mesophyll from being detached from the ribs.

Description

[0001] A Method of Producing Cheroots and Similar Tobacco Articles and an Apparatus for Preparing Wrappers by this Method.

[0002] In the production of cheroots and similar tobacco articles having a wrapper of natural tobacco no parts of the vein or central rib of the tobacco leaf are tolerated in the wrapper. Therefore, the vein is either removed from the tobacco leaf prior to stamping or cutting out the wrapper, or care is taken to locate the stamping cuts so as not to interfere with the central rib. On the other hand, parts of the side ribs of the leaf are accepted in the wrapper, but by the stamping operation it is attempted to avoid side rib parts in the end flap of the wrapper, i.e. the portion that forms rather over the last turn of the wrapper when overrolled. This is due to the fact, firstly, that side rib parts in the end flap irritate the lips, in particular if the wrapper is rolled over with the wrong or lower side outward which is frequently preferred with a view to the appearance of the finished cheroot and, secondly, that such side rib parts might cause the tip of the cheroot to be less resistant to mechanical damage.

[0003] As far as singular stamping-out operations are concerned, the operator may have this in mind when locating the leaf on the stamp or cutting tool, but in this case a certain waste of the comparatively expensive wrapper material must often be allowed for, because the number of possible cuts per leaf is reduced. The same applies to multi-stamping, i.e. when simultaneously using two or more stamps, and these tools must furthermore be mutually adjustable in order to fulfil the purpose, whereby the machinery and wage costs are considerably increased. A further known possibility is the cutting up of tobacco leaves into shreds or strips with a width corresponding to the width of the wrappers to be used and, after defective portions having been cut away, gluing these strips together into a consecutive tape from which the wrappers are cut out so as to avoid side rib parts in the end flaps. These operations may be controlled automatically, but for this purpose extremely expensive machinery is required.

[0004] Also within other branches of the cigar production the ribs of tobacco leaves give rise to difficulties, and even the French patent specification No. 572,737 that was published more than 50 years ago includes a proposal for evading such difficulties in connection with the preparation of filler tobacco. According to this proposal whole tobacco leaves are moistened just sufficiently so that they can be manually spread out or smoothed and are then heated, for example to 100°C, with a view to soften the ribs, in particular the central rib, whereafter the leaves when still moist and hot are passed between a pair of squeeze rollers for flattening of the ribs. The said reference states that the entire tobacco leaf including its ribs but with the exception of its stem can then be utilized as cigar filler material.

[0005] A corresponding proposal, exclusive of the step of heating, has been presented in the still older German patent No. 149,491.

[0006] A similar flattening has presumably been attempted in the processing of wrappers subsequent to the removal of the central rib of the leaves, but this does not appear to be described in literature.

[0007] Recent tests have proved that a cut wrapper with side ribs that have been flattened by use of the technique known from the cited patent specifications may be acceptable even though it contains rib parts in its end flap, as these side rib parts have lost a considerable portion of their rigidity and thickness, but it has also been found that an efficient flattening causes a material weakening of the mechanical strength of the leaf, particularly in the immediate vicinity of the ribs. In some cases the flattening operation was followed by a virtual perforation, inasmuch as the mesophyll was locally torn off the ribs, while the leaves in other cases apparently remained undamaged but, nevertheless, had been weakened so much that breakage or perforation showed up along the ribs in the subsequent overrolling operation.

[0008] Starting from the prior art discussed above, the invention relates to a method of manufacturing cheroots and similar tobacco articles comprising a wrapper cut out from natural tobacco and including parts of the side ribs of the tobacco leaf. The invention aims at providing a method of this type and so improved that the side ribs by flattening and without undue weakening of the mechanical strength of the leaf may be deformed to such a degree that they are tolerable even in the end flap of the wrapper.

[0009] This is achieved, according to the invention, by subjecting the moist tobacco leaf, or the wrapper cut out from it, to a rolling operation between a hard and a comparatively soft surface to flatten out the side ribs at least in the end flap of the wrapper.

[0010] It has not been fully elucidated why such a rolling between two differently hard surfaces on the one hand makes it possible to achieve the desired flattening of the ribs and, on the other hand, reduces the tendency to breakage, but a conceivable explanation is that a tobacco leaf even though carefully smoothed does not constitute a quite plane foil (the mesophyll) with uniformly located thickenings (the ribs), since naturally determined varieties from such a structure are prevailing, including local variations of the rib thickness, inter alia in connection with the secondary side ribs, and it is thinkable that the shearing forces between the mesophyll and the leaf rib caused by such varieties are compensated to a sufficient degree due to the slightly deformable character of the one rolling surface and so do not damage the leaves as it has been the case under other circumstances. Apparently, it does not matter how the leaves are turned during the rolling process, i.e. whether the wrong or lower side with protruding ribs faces the hard surface or whether the right or upper side does.

[0011] Irrespective of whether the rolling operation is carried out prior to the cutting-out of wrappers, i.e. of the stripped tobacco leaves, or subsequent to the cutting operation, considerable savings are made possible as far as the production of wrappers is concerned, because the wrappers may be cut out without regard to a special or optimum location of the rib parts.

[0012] Among the objects of the endeavours of rationalization made within the field of cigar production is that of separating the wrapper cutting operation from the overrolling operation, viz. by winding the wrappers on a bobbin subsequent to the cutting operation instead of applying them immediately to the overrolling operation..By use of this technique the method according to the invention may appropriately be practised in the way that the cloth of the bobbin during the winding or unwinding thereof is used as the comparatively soft surface in connection with a hard roller. This implies that the extra equipments needed to carry out the method are reduced to a minimum, since they for instance only consist in a pair of driven or idling squeeze rollers between which the bobbin cloth passes during winding and unwinding the wrappers.

[0013] The invention further relates to an apparatus for preparing wrappers according to the method concerned, said apparatus being characterised in that it comprises a side rib flattening device including a rotatable roller and an associated base, one of the said components having a.hard surface while the other has a comparatively soft surface. This comparatively soft surface suitably consists of a bobbin cloth running over a roller.

[0014] An embodiment of such an apparatus is more specifically explained in the following with reference to the drawing, which in perspective shows the relevant parts of the apparatus.

[0015] The apparatus includes a framework, not shown, in which a bracket 1 is disposed to receive a bobbin 2 with wrappers 3 cut out in a previous operation. The bobbin cloth 4 is pulled off in the direction of the arrows by means of a pair of co-operating driving rollers 5, after which the cloth may be wound for renewed use. During the pulling-off operation the bobbin cloth 4 passes across a table 6 that may contain a suction box contributing to holding the wrappers 3 against the cloth till they reach a take-off position from which they are transferred to a roll-making machine by means of a transfer mechanism 7 having a suction mouth piece 9 mounted on a pivot arm 8. The said roll-making machine is simply symbolized by a bloc 10 on the drawing. As indicated by the arrows, the pivot arm 8 and with it also the suction mouth piece 9 may by subjected to a vertical movement of displacement as well as to a movement of rotation, said movements being supposed to be conventionally co-ordinated with the advance movement of the bobbin cloth 4.

[0016] The bobbin cloth 4 and the wrappers 3 lying on it enter the table 6 via a pair of rollers 11 having a hard surface, for instance steel rollers, and provided with gear wheels 12 to secure the same circumferential velocity of both rollers. The wrappers 3 are subjected to a squeezing operation between said rollers 11 with the purpose of achieving a flattening of the side rib portions 13 occurring in the leaves, the bobbin cloth during this step acting as a comparatively soft coating on the lower roller whereby to prevent the wrappers from being mechanically damaged, in particular with a view to impede detachment of the mesophyll from the side ribs.

Claims

1. A method of manufacturing cheroots and similar tobacco articles comprising a wrapper cut out from natural tobacco and including parts of the side rib of the tobacco leaf, characterised in that the tobacco leaf, or the wrapper (3) cut out from it, in moist condition is subjected to a rolling operation between a hard surface (11) and a comparatively soft surface (4,11) to flatten out the side ribs (13) at least in the end flap of the wrapper.

2. A method according to claim 1 and in which the wrappers are wound on a bobbin (2) subsequent to the cutting operation, characterised in that the cloth (4) of the bobbin during the winding or unwinding thereof is used as the comparatively soft surface in connection with a hard roller (11).

3. An apparatus for preparing wrappers by the method set forth in claim 1 or 2, characterised in that it comprises a side rib (13) flattening device including a rotatable roller (11) and an associated base (4,11),one of the said components having a hard surface while the other has a comparatively soft surface.

4. An apparatus as claimed in claim 3, characterised in that the comparatively soft surface is constituted by a bobbin cloth.(4) running over a roller (11).

Drawing