US3272333A - Feed distributor for cigarettemaking machines - Google Patents

Description

A. PIETRUCCI Sept. 13, 1966 FEED DISTRIBUTOR FOR CIGARETTE-MAKING MACHINES Filed March 5, 1963 2 SheetsSheet 1 INVENTOR Andre Pietrucci Maxwell E. Sparrov ATTORNEY LLJJ Sept. 13, 1966 A. PIETRUCCI 3,272,333

FEED DISTRIBUTOR FOR CIGARETTE-MAKING MACHINES Filed March 5, 1965 2 Sheets-Sheet 2 l l I 9 l l I i 1 1 E a I g i Fig.3 I F194 l g 1 /g I I 13 I 1 1E Q 1 1 i I 1 I} l 1 1 j H J '16 5 u g 1 i I l 4 i I 15 1 1 I 1 1 1 i T E I l Q L Fig.6

I NVENTOR Andr Pietrucci BY Maxwell E. Sparrow ATTORNEY United States Patent 3,272,333 FEED DHSTRIBUTOR FOR CIGARETTE. MAKING MAQHINES Andr Pietrucci, Fleury-les-Aubrais, France, assignor to Service dExploitation Industrielie des Tabacs et des Allumettes, Paris, France Filed Mar. 5, 1963, Ser. No. 262,871 Claims priority, application France, Mar. 7, 1962, 890,239 3 Claims. (Cl. 209-85) The present invention relates to a distributor which is designed to feed the devices for forming the rod of tobacco of a cigarette-forming machine in such manner that the blended stock is supplied at a rate which is both constant and uniform.

Up to the present time, such objectives as the foregoing have been sought by combining the carding and crumbling of shredded tobacco.

The distributors which perform these operations mainly consist of a cylindersometimes a conveyor belt which is fitted with spikes or cards and which is covered in a continuous manner with shreds or bunches of shreds, these latter being stripped by the cards from the mass of tobacco which is made available at the upstream or input end and which is referred-to as a volute.

The movement and size of the said volute vary in the course of time in spite of the devices which are usually provided with a view to preventing such variations (floater, compacters, delivery racks). The uniformity with which the cards are covered consequently leaves much to be desired. Moreover, it is apparent that the breakage of the shreds which are carried forward by the cards does not necessarily occur along the envelope surface formed by the tips of the spikes but in those zones of the volute in which the resistance to tearing or rupture is lowest.

In order to overcome this disadvantage, the carding device conveys the tobacco and causes it to pass beneath an equalizer which is usually constituted by a cylinder which is fitted with very fine wire teeth card clothing and which is tangent to the previous cylinder along a generator-line and rotating in the same direction. The said equalized forces back any excrescences of shredded tobacco which may be carried by the carding unit.

In a final stage, the shreds conveyed through the carding unit are extracted from this latter by a crumbler, which is a cylinder of small diameter fitted with cockspurs, the tips of which penetrate between the rows of wire teeth of the cards. The rain of flakes produced by the crumbler falls onto a traveling band on which a certain blending process takes place by reason of the fact that a same point of the said travelling band receives flakes which are derived from various points of the carding machine.

The said blend is further improved as and when the flakes are transferred from the band to the tobacco feedbelt which is perpendicular to this latter.

However, the rate of delivery of the stream of tobacco which is discharged from a distributor of this type is far from being uniform on the scale of each individual cigarette and even on a higher scale, that is to say, on the scale of a group of cigarettes of a given stock. The results of measurements taken of the dispersion of weights are there to give evidence of this lack of uniformity.

In addition, the majority of forming machines are provided, prior to the final formation of the rod of tobacco, with one or a number of regularizing devices (peak clipper, rod-compensator, weighing device controlling the speed of the carding unit, etc.).

The main cause of this deficiency lies in the fact that distributors of the type referred-to above are not suitable ice for the purpose of ensuring the uniform treatment of a standard grade of cut tobacco which is heterogeneous from the point of view of the length of the flakes.

Moreover, in the distributors of the prior art, the operations of carding, equalizing and crumbling as described above are accompanied by an appreciable degradation of the cut tobacco.

In spite of the precautions taken to ensure that the degradation should prirnarly affect the longest shreds, since it is usually considered that these latter are not essential for the purpose of obtaining good compactness of the tobacco rod and prevent the constant progression of the stream, it is observed that the succession of breaks occurring as a result of pulling, shearing and torsional stress which are created in the conventional distributors also affect medium-length shreds which are thus broken and completely rejected in favour of the very short shreds which have a low filling value. An it is the short shreds which are largely the cause of losses from the ends which are sustained by cigarettes during handling operations.

It is thus essential on the one hand to limit the degradation solely to those shreds which are considered undesirable from the point of view of forming operations, that is to say, in the present state of knowledge, to shreds having lengths of more than 2 to 3 centimeters and, on the other hand, to ensure that there should exist in the interior of a tobacco rod having a length approximately equal to that of one cigarette a size distribution having characteristics which are as stable as possible, thereby substantially reducing the dispersion of the weight of the the cigarettes.

The present invention is directed to the construction of a distributor which is capable of supplying a forming machine with tobacco flakes in a continuous stream at a momentary rate which is as constant as possible and having a composition which is as homogeneous as possible, particularly from the point of view of size distribution.

To this end, the distributor in accordnace with the invention comprises, at the output end of a feeder and separator device designed to effect a substantial separation of the bunches of tangled shreds, means for selecting the shreds from at least two groups of shreds of different lengths, and adjustable means for the distribution of shreds associated with said selecting means and intended to deliver in a uniform manner and in requisite proportions a stream which is composed of shreds of the corresponding group.

In order to form the rod of tobacco, the distributor in accordance with the invention accordingly makes it possible to obtain a constant and uniform blend by carrying out the blending process according to the percentage of shreds of each group which exist in the initial product to be blended.

The means for selecting the shreds according to their dimensional characteristics are preferably constituted by screening surfaces provided with perforations of different size from one surface to the following surface and to which are imparted a movement which ensures the onward progression of the stream, for example by means of flat screens to which are imparted shaking movements.

The adjustable distribution means associated with the selection means can be constituted by tanks or wells, the bottom of which being formed by a screening surface provided with perforations of a size at least equal to the size of perforations characterizing respectively the selection means which are associated therewith, and to which are imparted vibrational movements of variable frequency and amplitude.

In a tank of this type, when the layer of product contained therein reaches a certain depth, the screen which forms the bottom thereof is in a so-called saturated state, or in other words the delivery of the said 3 screen then depends only on the amplitude and the frequency of the vibrational movement imparted thereto. It is accordingly merely necessary to produce action on these two variables in order to introduce into the final blend the shreds of each group according to the same proportions already existing in the initial product.

Rand-om variations in the delivery of each group of shreds are also corrected by the very fact of the existence of reserves up to a level above the bottom of the said tanks, the function of the said reserves being to ensure steadiness and uniformity of output and to maintain above the so-called saturation value the shred or flake layer which is intended to be fed directly into the blend and which calls for constant delivery.

In order to prevent any disturbances in the operation of the selection means, it is useful to provide pre-screening means between the separator device and said selection means and which are designed to permit the passage only of those shreds having a size either equal to or very slightly larger than that of the group corresponding to the largest size selected by said selection means.

In order to ensure that those shreds which have been rejected as oversize by the selecting means or by the pre-screening means may be re-introduced in the distribution system, a carding and crumbling unit is provided at the output end of the said means, and conveyor means bring back the said shreds after carding and crumbling to the input end of the said selection means.

Two examples of construction of the distributors in accordance with the invention have been illustrated in the accompanying drawings which are given solely by way of example and not in any sense by way of limitation, and in which:

FIG. 1 is a diagrammatic vertical sectional view of the complete device;

FIG. 2 is a plan view with portions broken away, of the device of FIG. 1;

FIG. 3 is a view in end elevation of one of the distribution tanks;

FIG. 4 is a partial view in side elevation of one of the tanks showing the elements which produce the vibrational motion;

FIG. 5 is a partial sectional view taken along the line aa of FIG. 4;

FIG. 6 is a partial plan view corresponding to FIG. 4, and

FIG. 7 is a diagrammatic vertical sectional view of an alternative form of the device as a whole.

As shown in FIGS. 1 to 6, the device which is intended to feed the units for forming the rod of tobacco of a cigarette-making machine, in accordance with the invention, essentially comprises:

A feeder and separator 1, a shaker conveyor 2 which is driven by a motor 3 and which comprises a number of selection or screening zones 4, 5, 6, the meshes of which have increasing sizes, a travelling band 7 which is fitted with brushes and which is intended to unclog periodically the meshes of the screens and, beneath the zones 4, 5 and 6, distribution tanks 8, 9, 10.

The tanks 8, 9, 10 which are held in position between frames 11 are mounted on springs or the like elastic support 12, there being imparted to the said tanks a vibrational movement which is transmitted thereto by a motor through the intermediary of a shaft 13, eccentrics 14 and connecting-rods 15. The plane of vibration is in this case horizontal. Inside the tanks are mounted screens 16 which form compartments 18, 19, 20 and screens 17 which form the bases of the said tanks. Each base is mounted beneath one of the screening zones 8, 9, 10 respectively, and the size of mesh of the screens fitted in said bases is at least equal to that of the screens of the corresponding zones 4, 5, 6.

An endless belt conveyor 21 collects in proper sequence the flakes which are dispensed by the tanks 8, 9, 10.

A device of conventional type comprising a belt conveyor 22 or a carding cylinder, combs 23 and a crumbling cylinder 24 is arranged at the downstream end of the screening zones. Vibrating bands or passageways 2'5, 26 and 27 collect the shreds which have been separated and crumbled and convey them to the input end of the feed on the shaker conveyor 2.

The mode of operation of the device which has been described in the foregoing is as follows:

The shreds of tobacco are introduced at 28 and, after a substantial separation process which does not impair the shreds, are directed by means of the feed separator 1 onto the shaker conveyor 2. On the said conveyor, the stream of tobacco shreds moves forwards over the screening zones 4, '5, 6 and successively abandons those shreds which are considered to be of maximum size for the purpose of constituting an homogeneous blend of uniform compactness. If it is conceded, for example, that the maximum desirable length of the shreds should be of the order of 20 millimeters, the screening zones can be constituted by screens having respectively 14, 8 and 5 meshes per inch. The size of mesh can vary as a function of the size distribution of the standard-grade tobacco employed. It will be understood that it will be possible to make provision for a larger or smaller number both of screening zones. and corresponding tanks depending on the proposed object of manufacture. Similarly, the area of the screening zones and the sizes of the tanks, which are unequal in volume, are regulated in relation to the speed of the devices for forming the rod of cigarette-tobacco, in such manner as to ensure suitable frequency and amplitude of the vibrational movements imparted to the shaker conveyor and to the tanks. The area of the screening zones will be regulated as a function of the required delivery of shreds of the category which can be screened in each zone, the said delivery depending also on the size composition of the type of cut tobacco employed.

The rate of delivery of a screen filled with a product which is intended to pass through the mesh of said screen is a function of the depth of the layer of product supported. When the depth of layer increases, the delivery first increases, then tends to become stable, irrespective of the depth. The screen is then said to be saturated. When the saturation depth is reached, the delivery of the screen then depends only on the amplitude and frequency of the vibrational movement. Suitable adjustable means A are provided to adjust the frequency and amplitude of the vibratory motion of the tanks.

The bottom screen 17 of each column 8, 9, 10 must satisfy two conditions. In the first place, it must be saturated. In the second place, the ratio of the delivery thereof to the total delivery of the distributor is equal to the average percentage of sheds present in the cut tobacco which are capable of passing through the mesh (and through the corresponding tank).

From one moment to another, the said percentage is subject to random variations, the effects of which are damped by the top screen or screens 16 of the tank. The variations in level in the said screen or screens results in varti-ons in deliverywhich become smaller as the depth of product progressively approaches saturation point which have no effect on the delivery of the bottom screen 17 if this latter is saturated.

Generally speaking, accompanying variations in level inside the bottom compartments 20, 20a, 20b initiate, depending on the level reached, either the starting or stopping of the feeder device 1.

It can happen that a variation in the size distribution of the cut tobacco takes place over a certain period of time. This variation is indicated by complementary variations in level in the top compartments. This circumstance is not attended by any disadvantage as long as the levels in the bottom compartments remain between the level of saturation and the maximum permissible level. If such a phenomenon were to last for a sufiiciently long period of time for one of these levels to be reached, it would accordingly be advisable to modify the characteristics of the vibrational movement imparted to the tanks concerned.

The output :by weight of the distributor as a whole in that case undergoes a variation. However, such a circumstance is not frequent if the dimensions of the tanks are such as to permit of a sufliciently substantial reserve supply of shreds which can be passed through the screens.

The belt conveyor 21 which is placed beneath the tanks 8, 9, effects the blending of the various products fed through the screens and the transportation of these latter towards the tobacco feed band.

The shreds which pass over the screens are evacuated at the downstream end of the shaker conveyor. These oversize rejects, which are mainly composed of shreds having a length which is greater than the limit fixed by considerations of uniformity of the rod of tobacco, are then received on the carding belt 22 which passes through the combs 23 and the crumbling cylinder 24-.

Allowance being made for the fact that the stream which passes out of the said unit is not intended to be received directly by the forming devices, the presence of an equalizing cylinder is not obligatory. For the same reason, the pressure of the combs can be very low. The setting of the spikes of the carding cylinder and the characteristics of the crumbling cylinder will be determined in such manner as to disentangle the long shreds and at the same time produce a reduction in length of these latter rather than uniformity of delivery.

The stream which passes out of the carding and crumbling unit is re-introduced as a continuous process at the input end of the shaker conveyor by a transporting means which is in this case consituted by vibrating bands or passageways 25, 26, 27. Since the point of re-introduction 29 is located at the upstream end of the main tobacco intake, those shreds which have been transferred through the carding and crumbling unit are screened first, by virtue of the fact that they are located beneath the input stream.

In the alternative form which is illustrated in FIG. 7, provision has 'been made for a pre-screening system 30, 31 at the input end of the selection screens 4, 5, 6 and at the output end of the separator 1. The mesh of the said screens is equal to or very slightly larger than the largest selection meshes, that is to say the mesh of the screen 6. The screened portion of the pre-screening system falls onto the shaker conveyor 2 and continues to travel directly towards the selection screens 4, 5, 6.

The oversize material rejected by the pre-screening system 30, 31 passes into the carding cylinder 32 and crumbling cylinder 33, at the output end of which the said material joins the previous stream on the passageway 2.

It can be seen in this example that the cut tobacco received by the shaker conveyor 2 is almost entirely made up of shreds which can pass through the screens. The separation process is consequently not hindered and the screens are no longer liable to clog.

Any material which may be rejected as oversize is received at 29 at the end of the apparatus by conveyors 25 and 27 and is returned thereon to the feed point.

It will be understood that the present invention is not limited in any sense to the constructional details which have been illustrated and described, and which have been given solely by way of example.

What I claim is:

1. A feed distributor for a cigarette-making machine comprising a feeder means for effecting a substantial separation of the bunches of tangled tobacco shreds, separating means for separating a portion of the shreds coming from said feeder means into at least two groups of shreds of different increasing lengths and temporarily storing a reserve thereof, a first conveyor means to carry said at least two groups of shreds to the cigarette-making machine, means for distributing each of said groups of said separated shreds onto said first conveyor means at a predetermined rate, means for adjusting the rate of distribution of each of said distributing means whereby said stream carried by said first conveyor means comprises predetermined proportions of said different groups of separated shreds, means for conveying another portion of the shreds rejected as oversize from said separating means to a location downstream of said separating means, means located at said location downstream of said separating means for carding and crumbling the shreds rejected as oversize by said separating means, and second conveyor means to bring back said oversize shreds after carding and crumbling upstream of said separating means.

2. A feed distributor for a cigarette-making machine comprising a feeder means for effecting a substantial separation of the bunches of tangled tobacco shreds, senarating means for separating a portion of the shreds coming from said feeder means into at least two groups of shreds of different increasing lengths, a first conveyor means to carry said at least two groups of shreds to the cigarette making machine, at least two vertical tanks having .a bottom opening and mounted each to receive and temporarily store a reserve of one of said dilferent groups of shreds of increasing lengths, screens closing the bottom opening of said tanks and provided with perforations of a size at least equal to the length of the corresponding shreds received by said respective tanks, said tanks being adapted to be driven in a vibratory motion of adjustable frequency and amplitude, means to drive each of said tanks in a vibratory motion of given frequency and amplitude, means located downstream of said separating means for carding and crumbling the shreds rejected as oversize by said separating means, and second conveyor means to bring back said oversize shreds after carding and crumbling upstream of said separating means.

3. A feed distributor for a cigarette-making machine comprising a feeder means for effecting a substantial separation of the bunches of tangled tobacco shreds, first means for separating the shreds having a length smaller than a predetermined maximum length, means for carding and crumbling the shreds rejected as oversize by said first separating means, second separating means for separating a portion of the shreds coming from said first separating means into at least two groups of shreds of different increasing lengths up to said maximum length, a first conveyor means to carry said at least two groups of shreds to the cigarette-making machine, at least two vertical tanks having a bottom opening and mounted each to receive and temporarily store a reserve of one of said different groups of shreds of increasing lengths, screens closing the bottom opening of said tanks and provided with perforations of a size at least equal to the length of the corresponding shreds received by said respective tanks, said tanks being adapted to be driven in a vibratory motion of adjustable frequency and amplitude, means to drive each of said tanks in a vibratory motion of given frequency and amplitude, and second conveyor means for conveying another portion of the shreds rejected as oversize from said second separating means and to bring back said oversize shreds upstream of said carding and crumbling means and said first separating means.

References Cited by the Examiner UNITED STATES PATENTS 54,263 4/1866 StOll 209341 X 635,076 10/1899 Perkins. 1,553,166 9/1925 Hutchinson 209-12 1,573,166 2/1926 Hutchinson 209317 X 2,035,701 3/1936 Greco 209-311 3,138,163 6/1964 Ffoulkes l311l0 ROBERT B. REEVES, Primary Examiner.

Claims (1)

1. A FEED DISTRIBUTOR FOR A CIGARETTE-MAKING MACHINE COMPRISING A FEEDER MEANS FOR EFFECTING A SUBSTANTIAL SEPARATION OF THE BUNCHES OF TANGLED TOBACCO SHREDS, SEPARATING MEAN FOR SEPARATING A PORTION OF THE SHREDS COMING FROM SAID FEEDER MEANS INTO AT LEAST TWO GROUPS OF SHREDS OF DIFFERENT INCREASING LENGTHS AND TEMPORARILY STORING A RESERVE THEREOF, A FIRST CONVEYOR MEANS TO CARRY SAID AT LEAST TWO GRPUPS OF SHREDS TO THE CIGARETTE-MAKING MACHINE, MEANS FOR DISTRIBUTING EACH OF SAID GROUPS OF SAID SEPARATED SHREDS ONTO SAID FIRST CONVEYOR MEANS AT A PREDETERMINED RATE, MEANS FOR ADJUSTING THE RATE OF DISTRIBUTION OF EACH OF SAID DISTRIBUTING MEANS WHEREBY SAID STREAM CARRIED BY SAID FIRST CONVEYOR MEANS COMPRISES PREDETERMINED PROPORTIONS OF SAID DIFFERENT GROUPS OF SEPARATED SHREDS, MEANS FOR CONVEYING ANOTHER PORTION OF THE SHREDS REJECTED AS OVERSIZE FROM SAID SEPARATING MEANS TO A LOCATION DOWNSTREAM OF SAID SEPARATING MEANS, MEANS LOCATED AT SAID LOCATION DOWNSTREAM OF SAID SEPARATING MEANS FOR CARDING AND CRUMBLING THE SHREDS REJECTED AS OVERSIZE BY SAID SEPARATING MEANS, AND SECOND CONVEYOR MEANS TO BRING BACK SAID OVERSIZE SHREDS AFTER CARDING AND CRUMBLING UPSTREAM OF SAID SEPARATING MEANS.

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