US3731693A

US3731693A - Machine and method for manipulating shredded tobacco

Info

Publication number: US3731693A
Application number: US00108792A
Authority: US
Inventors: F Pocock
Original assignee: Molins Machine Co Ltd
Current assignee: Molins Machine Co Ltd
Priority date: 1960-05-10
Filing date: 1961-05-09
Publication date: 1973-05-08
Anticipated expiration: 1990-05-08
Also published as: GB990567A; DE1296063B; CH377262A; BE603568A

Abstract

A method and machine for manipulating tobacco having a pneumatic system arranged to feed shredded tobacco upwardly on to the underside of a foraminous conveyor belt mounted below and adjacent to a horizontally elongated suction chamber in order to form a filler stream thereon which is later formed into a wrapped cigarette rod and cut into individual cigarettes. Tobacco is fed to the conveyor in excess of that required in the rod and the excess is removed by trimming in order to obtain uniformity in the rod. Inevitable variations in uniformity in the filler are reduced by controlling the degree of pneumatic compaction of the same by means of detectors which are arranged to manipulate a throttling or needle valve for controlling the degree of suction in the suction chamber thereby controlling the quantity of tobacco remaining between the trimming device and the conveyor and reducing variations in the filler when and if they should occur.

Description

United States Patent 1 Pocock 1 May8,1973

[54] MACHINE AND METHOD FOR MANIPULATING SHREDDED TOBACCO [75] Inventor: Frederick Pocock, Deptford, Lon- 211 App]. No.: 108,792

[30] Foreign Application Priority Data May 10, 1960 Great Britain ..l6,460/60 [52] US. Cl ..l31/21 B, 131/21 D, 131/84 B, 131/84 C [51] Int. Cl ..A24c 05/34 [58] Field of Search ..13l/21 B, 84,110, 131/21, 21 A, 84 B, 84 C; 19/70, 239, 240; 250/834 [56] References Cited UNITED STATES PATENTS 3,089,497 5/1963 Molins et al. ..l3l/84 C X 2,660,178 11/1953 Rault 3,039,473 6/1962 Schubert ..131/84 C 2,162,443 6/1939 Muller ..13l/2l A 2,516,932 8/1950 Wainwright ..l3l/2l B 2,938,521 5/1960 Lanore l3l/2l B 2,465,818 3/1949 Richardson 1 9/70 2,843,882 7/1958 Lewis et a]. ..19/70 2,981,986 5/1961 Neil ..l9/70 2,407,100 9/1946 Richardson ..l9/70 2,952,262 9/1960 Pecock et a1 ..l3 1/21 E FOREIGN PATENTS OR APPLICATIONS 385,946 2/1933 Great Britain..; ..l3l/21 A Primary Examiner-Joseph S. Reich AttorneyFrancis G. Cole [57] ABSTRACT A method and machine for manipulating tobacco having a pneumatic system arranged to feed shredded tobacco upwardly on to the underside of a foraminous conveyor belt mounted below and adjacent to a horizontally elongated suction chamber in order to form a filler stream thereon which is later formed into a wrapped cigarette rod and cut into individual cigarettes. Tobacco is fed to the conveyor in excess of that required in the rod and the excess is removed by trimming in order to obtain uniformity in the rod. lnevitable variations in uniformity in the filler are reduced by controlling the degree of pneumatic compaction of the same by means of detectors which are arranged to manipulate a throttling or needle valve for controlling the degree of suction in the suction chamber thereby controlling the quantity of tobacco remaining between the trimming device and the conveyor and reducing variations in the filler when and if they should occur.

4 Claims, 6 Drawing Figures PATENTEDHAY 81973 SHEET 3 OF 5 g azmw AT-romvsyg PATENTEU W 81973 SHEET b [1F 5 a "VW Wig v/lzi ATTORNE) PATENTEI] HAY 81973 sum 5 or s m iaf, wwwm ATTORNEK MACHINE AND METHOD FOR MANIPULATING SHREDDED TOBACCO This invention relates to tobacco-manipulating machines, such as continuous rod cigarette-making machines, in which a continuous tobacco filler is formed.

In U.S. Pat. application, Ser. No. 839,639, filed Sept. 14, I959, and now U.S. Pat. No. 3,089,497 granted May 14, 1963, there is disclosed a tobacco-manipulating machine in which a continuous filler is formed and is conveyed lengthwise on an air-pervious conveyor, air being passed through the filler and the conveyor to hold the filler suctionally to the conveyor. Means are provided to detect variations in a characteristic, (in this case, pressure drop, of the airflow through the filler, thereby to detect variations in the air-permeability of the filler, and the operation of a trimming device is controlled in accordance with said variations in the characteristic to remove surplus tobacco, to remove, or at least to reduce, variations of uniformity therein.

According to the present invention, in a tobaccomanipulating machine in which a continuous tobacco filler is formed, such as a cigarette-making machine of the continuous rod type, there is provided a method intended to improve the uniformity of the filler whlch includes the steps of feeding the filler lengthwise, trimming the filler to a desired cross-sectional size, subjecting the filler to a sensing operation to detect variations in the mass per unit length of the filler, and utilizing the results of the sensing operation to apply compensatory pressure to the untrimmed filler to modify the degree of compacting of the tobacco in the filler, at least during the trimming operation, which pressure is made greater or less according as the sensing operation indicated a less or greater quantity of tobacco passing the detector mechanism to remove, or at least, to reduce variations in average density, during trimming, of the tobacco across the cross-section of that part of the filler to be left after trimming.

The compensatory pressure applied in this way may be effected wholly upstream of the trimming operation, or it may be carried beyond the point of trimming. It is preferable that the compensatory pressure is so applied as to produce maximum compensating effect on the filler at the time of trimming.

Further according to the present invention, there is provided a tobacco manipulating machine in which a continuous tobacco filler is formed, such as a cigarettemaking machine of the continuous rod type, comprising means to feed the filler lengthwise, a trimming device to trim the filler to a desired cross-sectional size, sensing means to detect variations in the mass per unit length of the filler and compensating means to apply a compensatory pressure to the untrimmed filler to modify the degree of compacting of the tobacco in the tiller, at least during trimming. Means are provided to adjust the compensating means in accordance with the detected variations so that the compensatory pressure is made greater or less according as a less or greater quantity of tobacco passes the sensing means to remove, or at least, to reduce variations in average density, during trimming, of the tobacco across the crosssection of that part of the filler to be left after trimming. The filler is preferably conveyed lengthwise in contact with an air-pervious conveyor, air being passed through the filler and conveyor to hold the filler thereto, suctionally.

The compensatory pressure may be air pressure which is controlled by varying air flow through the filler and the conveyor. 7

The flow of air which is controlled to provide the compensatory pressure passes at least through a length of filler immediately preceding the trimming operation.

Thus the compensating means may comprise a chamber having an opening adjacent the conveyor and extending to the trimming device, means being provided to draw air through the chamber, the conveyor and the filler. Pressure in the chamber may be varied by a butterfly valve or a bleed valve in the wall of the chamber.

Alternatively, the compensatory pressure may be applied to the filler by mechanical means, such as a roller, to contact the filler, and movable towards and away from the conveyor to vary the pressure exerted on the filler.

The compensatory pressure may be controlled by air-sensing means, such as the means disclosed in U.S. application, Ser. No. 839,639 now U.S. Pat. No. 3,089,497, issued May 14, 1963, or may be under the control of a nucleonic detector.

The compensatory pressure may be such as always to increase the compacting of the filler during normal operation of the machine, i.e., the compacting of the more compacted lengths of the filler is increased but to a less extent than that of the less compacted lengths.

Two embodiments of apparatus according to the invention will now be described, by way of example, with reference to the accompanying drawings, of which:

FIG. 1 is a front elevation, partly in section, of part of a continuous rod cigarette-making machine, and shows a first embodiment of the invention,

FIG. 2 is an enlarged view, in section, of part of FIG. 1 to show details of the chambers 10 and 13 of the first embodiment,

FIG. 3 is a detail view, partly in section, on line 3--3 in FIG. 2 to show details of the first embodiment, and

FIG. 4 shows a first modification partly in section of the first embodiment,

FIG. 5 shows a second modification partly in section, of the first embodiment, and

FIG. 6 is a view corresponding to FIG. 1 of a second embodiment.

In the machine illustrated in FIG. 1, cut tobacco is fed into a high velocity current of air and is impelled by the current of air to an air-pervious conveyor in the form of a perforated metal conveyor band 1 which runs through the upper part of a narrow passage 2 through which the air flows upwardly. The tobacco so fed is suctionally held on the underside of the conveyor band 1, on which the tobacco builds up to form a continuous filler, by means of air drawn through the tobacco and the conveyor band 1 into a suction chamber 4. The tobacco filler is carried by the conveyor band 1 from right to left as shown in the drawings through a channel open to atmosphere and comprising opposed walls 9 which confine the tobacco laterally. A pipe 5, the end of which is shown in FIG. 1, extends from the suction chamber 4 to pumping means (not shown) which withdraws air from the suction chamber and maintains a pressure lower than atmospheric pressure therein. Beyond the passage 2 there is provided a trimming device 6 which removes surplus tobacco from the filler. The trimming device 6 comprises two cooperating trimming discs, but only one is shown. The filler is transferred from the conveyor band 1 on to a continuous paper web 3 which forms the continuous paper wrapper which is folded over the trimmed filler to form the continuous cigarette rod. The machine as so far described is described more fully in, for example, US. Pat. Application Ser. No. 787,954, filed Jan. 20, 1959 and now US. Pat. No. 3,088,468 granted May 7, 1963.

FIGS. 1, 2 and 3 will now be referred to.

The amount of tobacco which is removed from the filler is varied in accordance with variations in the air permeability of the filler. A sensing chamber 10 is pro vided above the conveyor band 1 and has an opening 1 1 which is in communication with a short length of the conveyor band of less than a cigarette length. A pipe 12 extends from the chamber 10 into the pipe 5 so that air is drawn through the filler, the conveyor band and the chamber. Thus, depending on the air permeability of the length of filler at any instant below the chamber 10, the pressure in chamber will be varied and these variations provide an indication of variations in uniformity of the filler along its length.

For the purposes of the present explanation, the trimming device 6 will be considered to be fixed in position relative to the conveyor band 1 when the filler will be trimmed to a constant cross-sectional area delineated by the discs of the trimming device, the walls 9 and the band 1. If the average density of the tobacco across this cross-sectional area remained constant as the filler moved past the trimming device the mass per unit length of the trimmed filler would, of necessity, also be constant. It is found, however, that if the effect of suction on the filler is considered, there will be a greater flow of air through a given length of filler stream containing relatively little tobacco than through a similar length containing a relatively large quantity of tobacco and thus there will be a smaller pressure drop i.e., a higher pressure in chamber 10, in the first case than in the second case.

The degree of compacting of the tobacco, and therefore the average density of the tobacco, between the level at which the trimming device operates and the conveyor band 1 is dependent on the pressure drop across the untrimmed filler stream, an increase in pressure drop producing a greater degree of compacting, and a greater average density, and vice versa. The mass per unit length of the trimmed filler will be greater where the tobacco has been subjected to a greater degree of compacting and thus the mass per unit length of the trimmed filler depends on the pressure drop which has been applied to the untrimmed filler stream. As the applied pressure drop depends on the quantity of tobacco in the untrimmed filler stream the mass per unit length of the trimmed filler will vary in the same sense as the mass per unit length of the untrimmed filler stream.

However, it is found that the variations in mass per unit length of the trimmed filler are smaller than the corresponding variations of the untrimmed filler stream, and also that the variations of the untrimmed filler stream are a smaller proportion of the mean weight of that stream than the variations of the trimmed filler are of the mean weight of the trimmed filler.

To avoid, or at least to reduce, these residual variations in the trimmed filler, compensator means are provided to modify the degree of compacting of the tobacco in the filler as it is operated on by the trimming device to remove, or at least to reduce, variations in the compacting and therefore in the average density of the portion of the filler between the level at which the trimming device 6 operates and the conveyor band 1.

The compensator means comprises a chamber 13, which may conveniently be similar to the chamber 10. This chamber 13 has an opening 14 in its underside which communicates with the conveyor band 1. The chamber 13 is situated downstream of the chamber 10. The downstream end of the chamber 13 is situated directly above the position at which the filler first contacts the trimming device.

A pipe 15 extends from the chamber 13 to a separate fan 16 which operates to draw air through the filler, the conveyor band 1 and the chamber 13. Pressure-varying means in the form of a throttle valve 17 is provided in the chamber 13, the throttle valve being of the butterfly type and aerodynamically balanced so that there is little or no net turning moment on the valve due to air flowing through the chamber 13. The spindle 18 of the valve 17 carries a bevel gear 24 which meshes with a similar gear 25 carried on a spindle 26 which has a thread of long pitch which cooperates with a similar thread in the bore of a nut member 19 carried by one end of a resilient bellows 20 secured to a bracket 27 outside the suction chamber 4. A pair of collars 28 are provided on the spindle 26, one on each side of the wall of the suction chamber 4 to prevent axial movement of the spindle.

The pressure within the chamber 10 is communicated to the interior of the bellows 20 by means of a pipe 21. The chamber 10 is spaced from the chamber 13 so that the time interval between a pressure variation occurring in the chamber 10 and a corresponding rotation of valve 17 is the same as the time taken" by the filler to travel from beneath the centre of the chamber 10 to beneath the downstream end of chamber 13.

The nut member 19 has a projection 22 which is slidable in an axially-extending slot in a guide 23 carried by the suction chamber 4.

Thus, variations in pressure in the chamber 10 cause the bellows 20 to expand or contract and move the nut member 19 along the spindle 26 thus causing it to rotate, and through the bevel gears 24, 25, to rotate the valve 17.

The manner of operation of the chambers 10 and 13 is as follows. As the filler passes under the chamber 10 variations in air pressure will occur therein due to variations in air permeability of the filler, arising from variations in the mass per unit length of the filler. As mentioned above, these variations in permeability result in a greater pressure drop occurring across lengths of the filler having a relatively large mass per unit length, thus causing a greater degree of compacting of the tobacco in the filler, so that the trimmed filler would be more compacted and dense along these lengths than in the case of lengths of filler having a relatively small mass per unit length. When a length having a relatively large mass per unit length is under the chamber 10, a lower pressure is present in that chamber, and the bellows 20 contracts. The nut member 19 turns the spindle 26 and the throttle valve 17 rotates to a position in which it provides a greater restriction to flow through the chamber 13 when that same length of filler is below the chamber 13. A higher pressure is thus produced between the throttle valve 17 and the band 1 and consequently there is a smaller pressure drop across the tiller under the chamber 13. This allows the filler to expand downward slightly, thus reducing the degree of compacting of the layers of tobacco in the tiller and reducing the average density of the tobacco in the filler as it reaches the trimming device 6. With a length of filler having a relatively low mass per unit length the opposite occurs. Therefore variations in the compacting and average density of the filler as it is trimmed are avoided, or at least are reduced, and a more uniform filler results.

As a little time is necessary for the tobacco in the filler to adjust itself to any different pressure drop to which it is subjected under the chamber 13 the slot 14 must be of sufficient length for the tobacco in the filler to respond to the controlled air flow through it.

The trimming device has been considered as being fixed relative to the conveyor band 1 but, inaddition, apparatus is provided downstream of the trimming device 6 to provide a check on the mean mass per unit length of the filler, and the trimming device is moved towards or away from the conveyor band 1 in response to variations in the mean mass per unit length of the filler to provide a correction for such variations. These variations are detected by scanning apparatus utilizing a source of beta radiation. Such apparatus is disclosed, for example, in US. application, Ser. No. 839,639, now Pat. No. 3,089,497, and is indicated diagrammatically in FIG. 1.

The trimming device 6 is supported by a link 50 pivotally connected to a lever 51 pivotally mounted in stationary structure at its right hand end 52. At its left hand end the lever 51 carries a nut member 53 in which is threaded a screwed member 54 on which is provided a wormwheel 55. Rotation of the wormwheel 55 in one direction or the other thus raises and lowers the left hand end of the lever 51, and with it the trimming device 6, so varying the cross-sectional area of filler between the side walls 9, conveyor band 1 and the trimming discs 6. The wormwheel is rotated by a worm 56 carried on the spindle of a reversible electric motor 57. A source of penetrative radiation such as Strontium 90 is indicated at 58. This is positioned adjacent the wrapped cigarette rod made on the machine, a length of which is indicated at C and, on the other side of the cigarette rod is an ionisation chamber 59. A similar source and ionisation chamber are shown at 60 and 61 respectively, but with a standard metal screen 62 interposed between them which has a ray absorption equal to that of the desired mass of the cigarette rod. It will be appreciated that the cigarette rod is the trimmed filler with a paper wrapper and its mass per unit length is therefore substantially the same as the trimmed filler. The outputs of the two ionisation chambers 59 and 61 are arranged electrically in opposition and the resultant current is the difference of the two inputs, and its direction depends on whether the cigarette rod is lighter or heavier than desired. The resultant current is fed to an amplifier 63, the output of which drives the electric motor. Thus, if the mean mass per unit length of the cigarette rod, and thus of the trimmed filler, is too low the electric motor 57 rotates to lower the trimming discs 6 away from the conveyor 1 and thus increase the cross-sectional area of the trimmed filler between the trimming discs and the conveyor.

In the modification shown in FIG. 4 the pressurevarying means for the compensator chamber 13 comprises, in place of the throttle valve 17, a needle valve to admit a flow of air from atmosphere into the chamber 13 which by-passes the tobacco filler. A pipe 29 extends from the chamber 13 through the wall of the suction chamber 4 so that its other end is open to atmosphere and also constitutes the seat 30 of the needle valve. A rod 31 extends from the bellows 20 and carries a profiled needle valve member 32 which protrudes into the orifice and varies its effective area. Thus, as the pressure in chamber 10 increases, the bellows 20 expands, moving the valve member 32 into the orifice 30 to decrease its effective area, and thus the amount of air drawn into the chamber 13 by the fan 16, so that the pressure in chamber 13 falls, and the pressure drop across the tobacco filler under the chamber 13 increases. If the pressure in chamber 10 decreases, the opposite effect occurs.

Apparatus measuring the mean mass per unit length of the trimmed filler could also be made to adjust a needle valve such as valve 32 instead of raising and lowering the trimming device 6. Thus, as shown in FIG. 5, the spindle of the reversible electric motor 57 shown in FIG. 1, instead of driving the worm 56 and wormwheel 55, carries an internally threaded nut member which receives the threaded end of a rod 71. The rod 71 carries a profiled needle valve member 72, similar to the valve member 32, and this protrudes into a seat 73 in the wall of the chamber 13, similar to the seat 30. Rotation of the rod 71 is prevented by any conventional means. The motor 57 is restrained from rotation by being carried by a bracket 74 secured to the chamber 13. Rotation of the spindle of the motor 57 thus moves the valve member 72 into or out of the seat 73 depending on whether the cigarette rod, and thus the trimmed filler, is light or heavy.

This arrangement may be in addition to the valves shown in FIGS. 3 or 4 or may be the sole control for varying the air pressure in the chamber 13, and thus the compensatory pressure. In the latter case, of course, the sensing chamber 10 and bellows 20 would not be provided.

A separate fan, such as fan 16, need not be used to withdraw air from the compensator chamber 13. Thus the pipe 15 could be led into pipe 5, as with the pipe 12 from the sensing chamber 10. However, if a different datum for the pressure in chamber 13 compared with that in chamber 10 is desired, this is more easily ob tained by using a separate fan. For example, it may be desired that there should be a lower datum for the pressure in the compensator chamber 13. Thus the pressure drop across the filler under the chamber 13 may always be such as to increase the compactness of the filler. Then, if the pressure drop across the filler under chamber 10 decreases, the pressure drop across the filler under chamber 13 will increase to increase the degree of compacting of the filler; if the pressure drop across the filler under the chamber 10 increases, the pressure drop produced by chamber 13 will decrease,

but will still be such as to increase the degree of compacting of the layers of tobacco in the filler, but to a lesser extent.

In the second embodiment of the invention illustrated in FIG. 6 the compensatory pressure is applied by mechanical means. In this embodiment the chamber 13 is replaced by a roller 80 which is pivotally mounted on the end of an arm 81 which is pivotally mounted at its other end on the shaft 82 carrying the sealing device 83. The sealing device 83 is no part of the present invention but is fully described in U.S. Appln., Ser. No. 856,131 filed Nov. 30, 1959 and now U.S. Pat. No. 3,091,244 granted May 28, 1963. The roller 80 runs in contact with the lower surface of the untrimmed tobacco filler and is movable towards and away from the conveyor l to vary the compensatory pressure applied to the filler by raising and lowering of the arm 81. To effect such movement of the arm 81, a rod 84 has its lower and hooked end pivotally connected to the arm 81 adjacent the roller. The upper end of the rod 84 is connected to the output member 85 of a hydraulic servo device indicated generally at 86. Such a servo device is described fully in, for example, US. application Ser. No. 839,639, now Pat. No. 3,089,497. The input member of the servo device is indicated at 87, and is operated by a pivoted lever 88, which in turn is operated by the free end of a bellows 89, which may be identical with the bellows 20 shown in FIG. 3. A sensing chamber 90, identical with chamber of FIGS. 1 and 2, is provided and performs identical functions. Pressure variations in the chamber 90 are communicated to the bellows 89 by a pipe 91. Thus expansion and contraction of the bellows 89 in response to varying pressures in the chamber 90 result in raising and lowering of the roller 80 to apply a varying compensatory pressure to the filler and modify its compacting to remove, or at least to reduce, variations in the average density of the portion of the tobacco filler between the trimming device 6 and the band 1.

As with the construction of FIG. 1 the trimming device 6 is raised and lowered under control of a nucleonic sensing device as described with reference to FIG. 1.

To assist the tobacco filler to reach its modified degree of compacting under control of the compensating means described, it may be necessary for the side walls 9 to be inclined at an angle less than a right angle to the conveyor band 1. This is shown in FIGS. 3, 4 and 5.

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

1. In an industrial processing system using compressible material to form a product and including a conveyor for said material, and means for feeding an amount of said material to said conveyor in excess of that required to form the product, the material on said conveyor having a free surface, a control system for controlling the quantity of said material used in forming said product, said control system comprising separating means for separating said material into a first portion of predetermined cross section and a second portion containing the excess, adjustable means for pressing the free surface of said material with a pressure exceeding atmospheric pressure toward said conveyor ahead of said separating means thereby controlling the density of said material as conveyed to said separating means, means for feeding said separated first portion to form said product, detecting means for detecting the quantity of said material in said product, and means responsive to said detecting means for controlling said adjustable means in accordance with the quantity of said material detected to maintain said quantity constant.

2. A machine for producing a tobacco rod containing a predetermined quantity of tobacco per unit length thereof, comprising conveyor means defining an elongated path and having an elongated groove which defines a first portion of said path; means for feeding a mass of tobacco into said path in such quantities that the tobacco forms a moving stream having an exposed side and containing tobacco in excess of that required in the tobacco rod; trimming means adjacent to said groove for removing excess tobacco from the stream whereby the remainder of the stream forms a tobacco rod; compacting means located upstream of and in close proximity to said trimming means, said compacting means including biasing means arranged to subject the exposed side of the stream to the action of a mechanical compacting force acting in a direction transverse to the direction of movement of the tobacco stream, said compacting means being adjustable; testing means adjacent to a second portion of said path for measuring the quantity of tobacco per unit length of the mass of tobacco moving in said second portion of the path; and adjusting means operatively connected with said testing means for adjusting said biasing means so as to reduce the compacting force of said biasing means when the measured quantity exceeds said predetermined quantity and to increase the compacting force of said biasing means when the measured quantity is less than said predetermined quantity.

3. A machine for producing a tobacco rod containing a predetermined quantity of tobacco per unit length thereof, comprising conveyor means defining an elongated path and having an elongated groove which defines a first portion of said path; means for feeding a mass of tobacco into said path in such quantities that the tobacco forms a moving stream having an exposed side and containing tobacco in excess of that required in the tobacco rod; trimming means adjacent to said groove for removing excess tobacco from the stream whereby the remainder of the stream forms a tobacco rod; compacting means located upstream of and in close proximity to said trimming means, said compact-l ing means including biasing means arranged to subject the exposed side of the stream to the action of a mechanical compacting force acting in a direction transverse to the direction of movement of the tobacco stream, said compacting means being adjustable; testing means adjacent to a second portion of said path for measuring the quantity of tobacco per unit length of the mass of tobacco moving in said second portion of the path; adjusting means operatively connected with said testing means for adjusting said biasing means so as to reduce the compacting force of said biasing means when the measured quantity exceeds said predetermined quantity and to increase the compacting force of said biasing means when the measured quantity is less than said predetermined quantity; and wrapping means located downstream of said trimming means for applying a continuous wrapper around the tobacco rod and for thus transforming the tobacco rod into a wrapped tobacco rod, said testing means being located downstream of said trimming means for measuring the quantity tobacco per unit length of the tobacco rod.

4. A method of producing a wrapped tobacco rod which contains a predetermined quantity of tobacco per unit length thereof, comprising the steps of forming a tobacco stream having an exposed side and containing tobacco in excess of that required in the tobacco rod; moving the stream in a predetermined path; compacting the stream by subjecting said exposed side to the action of a mechanical compacting force acting in a direction transverse to the direction of movement of the stream; trimming the thus compacted stream by removing excess tobacco along said exposed side of the stream whereby the remainder of the stream forms a tobacco rod; wrapping said tobacco rod into a continu ously supplied wrapper to form a wrapped tobacco rod; measuring the quantity of tobacco per unit length of the tobacco rod; and adjusting the compacting force in accordance with the measured result by reducing the compacting force when the measured quantity exceeds said predetermined quantity and by increasing the compacting force when the measured quantity is less than said predetermined quantity.

Claims

3. A machine for producing a tobacco rod containing a predetermined quantity of tobacco per unit length thereof, comprising conveyor means defining an elongated path and having an elongated groove which defines a first portion of said path; means for feeding a mass of tobacco into said path in such quantities that the tobacco forms a moving stream having an exposed side and containing tobacco in excess of that required in the tobacco rod; trimming means adjacent to said groove for removing excess tobacco from the stream whereby the remainder of the stream forms a tobacco rod; compactiNg means located upstream of and in close proximity to said trimming means, said compacting means including biasing means arranged to subject the exposed side of the stream to the action of a mechanical compacting force acting in a direction transverse to the direction of movement of the tobacco stream, said compacting means being adjustable; testing means adjacent to a second portion of said path for measuring the quantity of tobacco per unit length of the mass of tobacco moving in said second portion of the path; adjusting means operatively connected with said testing means for adjusting said biasing means so as to reduce the compacting force of said biasing means when the measured quantity exceeds said predetermined quantity and to increase the compacting force of said biasing means when the measured quantity is less than said predetermined quantity; and wrapping means located downstream of said trimming means for applying a continuous wrapper around the tobacco rod and for thus transforming the tobacco rod into a wrapped tobacco rod, said testing means being located downstream of said trimming means for measuring the quantity tobacco per unit length of the tobacco rod.

4. A method of producing a wrapped tobacco rod which contains a predetermined quantity of tobacco per unit length thereof, comprising the steps of forming a tobacco stream having an exposed side and containing tobacco in excess of that required in the tobacco rod; moving the stream in a predetermined path; compacting the stream by subjecting said exposed side to the action of a mechanical compacting force acting in a direction transverse to the direction of movement of the stream; trimming the thus compacted stream by removing excess tobacco along said exposed side of the stream whereby the remainder of the stream forms a tobacco rod; wrapping said tobacco rod into a continuously supplied wrapper to form a wrapped tobacco rod; measuring the quantity of tobacco per unit length of the tobacco rod; and adjusting the compacting force in accordance with the measured result by reducing the compacting force when the measured quantity exceeds said predetermined quantity and by increasing the compacting force when the measured quantity is less than said predetermined quantity.