US3831610A - Machine for blending tobacco or the like - Google Patents

Abstract

A machine for blending various types of tobacco has a blending unit and several conveyor lines which supply to the blending unit different types of tobacco and at least one of which contains at least one adjustable processing apparatus for the treatment of the respective tobacco type. One or more signal generating detectors are provided in at least one other conveyor line to scan the rate of supply of tobacco and to adjust operating means for the processing apparatus in dependency on changes in the tobacco supply.

Description

iii; States Patent [191 Wochnowski et a1.

[451 Aug. 27,1974

[ MACHINE FOR BLENDING TOBACCO 0R T111151 LIKE [75] Inventors: Waldemar Wochnowski,

Hamburg-Volksdorf; l'lelmut Baumann, Hamburg-Bergedorf, both of Germany [73] Assignee: Hauni-Werke Korber & Co. KG,

Hamburg-Bergedorf, Germany [22] Filed: July 2, 1971 [21] App]. No: 159,350

Related US. Application Data [62] Division of Ser. No, 635,597, May 2, 1967, Pat. No.

[30] Foreign Application Priority Data May 4, 1966 Germany 5930079 May 13, 1966 Germany 5939079 May 17, 1966 Germany 5942679 [52] 11.8. C1. 131/21R,131/21 A, 131/21 B, 131/22,131/22 A, 131/135, 131/108, 131/149 [51] Int. Cl. A24b 07/ 141, A24b 09/00 [58] Field of Search 121/21, 21 B, 22, 22 A, 121/108, 135, 133, 138, 146, 149; 131/21 A,

[56] References Cited UNITED STATES PATENTS 1,975,719 10/1934 Harris 1. 131/135 X 2,229,942 1/1941 2,827,058 3/1958 2,861,683 11/1958 3,419,015 12/1968 Primary Examiner-Joseph S. Reich Attorney, Agent, or FirmMichae1 S. Striker ABSTRACT A machine for blending various types of tobacco has a blending unit and several conveyor lines which supply to the blending unit different types of tobacco and at least one of which contains at least one adjustable processing apparatus for the treatment of the respective tobacco type. One or more signal generating detectors are provided in at least one other conveyor line to scan the rate of supply of tobacco and to adjust operating means for the processing apparatus in dependency on changes in the tobacco supply.

10 Claims, 14 Drawing Figures mjfmmmznm 3,33. @610 2059 2060 2050 2065 I x Fig. 3

2072 INVENTO L lbygnuz 55 23 [Jamar 34 I! MACHINE FOR BLENDING TOBACCO OR THE LIKE CROSS REFERENCE TO RELATED CASES BACKGROUND OF THE INVENTION The present invention relates to blending of fibrous materials, particularly to blending of tobaccos. Still more particularly, the invention relates to improvements in machines which can be utilized for blending different classes, types, qualities, grades or vintages of tobacco.

Blending is one of the most complex and important procedures in the manufacture of cigarettes, cigars and other tobacco products. This is due to the fact that all advantageous characteristics which a smoker, sniffer or chewer expects from his or her preferred brand cannot be obtained by utilizing a single type, class, grade or quality of leaf. For example, one type of leaf may be highly aromatic but does not burn well, and another type of leaf may be too strong or too weak. Manufacturers of tobacco products have developed recipes for blending different tobacco types in such a way that a blend normally contains leaf from two or more years crops and that such blend contains a mixture of Oriental with Burley, Virginia, Maryland, flue-cured and/or others.

Serious problems arise when the blending of different tobacco types is carried out on a large scale with automatic machinery. As a rule, different tobacco types are treated separately prior to blending, and the resulting mixture or blend then undergoes one or more additional treatments. This is due to the fact that different tobacco types must be treated in different apparatus and also because a specific treatment which is needed for one tobacco type might not be needed at all for another tobacco type. For example, the treatment of Oriental tobaccos following moistening of bales is very simple and consumes little time. On the other hand, the preliminary treatment of Burley (prior to blending) is much more extensive and consumes more time.

An object of the invention is to provide a novel and improved automatic machine which can blend two or more tobacco types in such a way that the ratio of tobaccos in the blend varies little or not at all.

Another object of the invention is to provide a machine which can blend tobaccos and maintains a dc sired ratio between various tobacco types regardless of differences in time required for preliminary treatment of individual tobacco types.

A further object of the invention is to provide a machine which can blend two or more tobacco types by maintaining the desired ratio regardless of anticipated or unforeseen fluctuations in the rate of delivery of such tobacco types.

An additional object of the invention is to provide a machine which can be reset to form different blends and which can be converted from blending of two tobacco types to blending of three or more tobacco types, or vice versa.

Another object of the invention is to provide a machine which can automatically terminate the blending of two or more tobacco types when the resulting blend contains a predetermined amount of a given tobacco type.

A further object of the invention is to provide a blending machine whose operation is independent of the number of treatments to which the tobacco types must or should be subjected prior to blending.

SUMMARY OF THE INVENTION The invention is embodied in a machine for blending various types of tobacco or like fibrous materials which comprises blending means, at least two conveyor lines for supplying to the blending means different types of material, at least one adjustable processing apparatus provided in at least one of the conveyor lines and operative to treat the respective material type, signal generating detector means for detecting changes in the rate of supply of material by one of the conveyor lines, and operating means for adjusting the processing apparatus in response to signals from the detector means. The detector means and the processing apparatus can be provided in the same conveyor line and each conveyor line can be arranged to supply the respective material on a batch basis. The detector means can be designed to respond to the presence and/or absence of material in the respective conveyor line.

The novel features which are considered as characteristic of the invention are set forth in particular in the appended claims. The improved blending machine itself, however, both as to its construction and its mode of operation, together with additional features and advantages thereof, will be best understood upon perusal of the following detailed description of certain specific embodiments with reference to the accompanying drawing.

BRIEF DESCRIPTION OF TlHE DRAWINGS FIG. 1 is a flow sheet illustrating in diagrammatic form certain elements of a machine which may be utilized for automatic blending of two tobacco types;

FIG. 2 is a similar flow sheet illustrating certain elements of a machine which is intended for blending of three tobacco types;

FIG. 3 is a flow sheet illustrating a blending machine which constitutes a modification of the machine shown in FIG. 2;

FIG. 4 is a flow sheet illustrating a blending machine which constitutes a modification of the machine shown in FIGS. 2 or 3;

FIG. 5 is a fragmentary top plan view of a blending machine which is similar to the machine represented by the flow sheet of FIG. 1;

FIG. 6 is a fragmentary top plan view of a blending machine which constitutes a first modification of the machine shown in FIG. 5;

FIG. 7 is a fragmentary top plan view of a blending machine which constitutes a second modification of the machine shown in FIG. 5;

FIG. 8 is a fragmentary schematic side elevational view of a further blending machine;

FIG. 9 is a fragmentary schematic view of a blending machine for blending two types of tobacco, Virginia and Oriental, for example;

FIG. is a schematic view of a first modification of the blending machine shown in FIG. 9;

FIG. 11 is a schematic view of a second modification of the blending machine shown in FIG. 9;

FIG. 12 is a schematic view of a third modification of the blending machine shown in FIG. 9;

FIG. 13 is a top plan view of a time-lag unit which can be utilized in the blending machines of FIGS. 1 to 4; and

FIG. 14 is a vertical section substantially as seen in the direction of arrows from the line XIV-XIV of FIG. 13.

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a flow sheet illustrating in diagrammatic form a machine for blending two tobacco types, grades, classes or qualities. The numerals 2001 and 2002 denote two conveyor lines each of which advances one of the two tobacco types. The lines 2001 and 2002 deliver tobacco to a blending means or blending unit 2 (e.g., a rotary drum) which occupies a blending location, and the resulting blend is advanced by a common conveyor line 2003. The first tobacco type which is advanced in the path defined by the conveyor line 2001 is treated during passage through a pair of serially arranged processing apparatus 2006 and 2007, and the second tobacco type which is advanced in the path defined by the conveyor line 2002 is treated during passage through processing apparatus 2008 and 2009. A further processing apparatus 2005 treats blended tobacco which is advanced in the path defined by the common conveyor line 2003. Depending on the nature of the first and second tobacco types, the processing apparatus 2005 and 2009 may include moistening, casing-applying, cooling, drying, cutting, heating, destalking, mixing, bulking and other devices. A proportioning or metering unit 2010 is installed in the conveyor line 2001 downstream of the processing apparatus 2006,2007, i.e., this proportioning unit 2010 is the last unit through which the first tobacco type passes on its way to the blending location which accommodates the blending unit 2004. The proportioning unit 2010 comprises an automatic feeder 2011 which has storage capacity, a weighing or measuring conveyor 2012 which determines the rate of tobacco flow toward the blending unit 2004, and a regulator or speed changer 2013 which controls the operation of the associated automatic feeder 2011. The weighing conveyor 2012 supplies to the regulator 2013 impulses which indicate the actual rate of tobacco flow and the regulator 2013 changes the delivery of the feeder 2011 when such actual rate deviates from a predetermined or desired rate. The feeder 2011 is capable of storing a variable quantity of tobacco and insures that the rate at which the weighing conveyor 2012 receives tobacco is a function of the difference between the desired and actual rates.

The second conveyor line 2002 accommodates a weighing or measuring conveyor 2014 which is located downstream of the processing apparatus 2008,2009. The weighing conveyor 2014 supplies to the regulator 2013 impulses which indicate the aforementioned predetermined or desired rate of tobacco flow through the weighing conveyor 2012 in the conveyor line 2001. The conveyor lines 2001,2002 further accommodate two delay or time- lag units 2015,2016 which are set in such a way that the time required by successive increments of the first tobacco type to cover the distance between the proportioning unit 2010 and the blending unit 2 is the same as the time required by successive increments of the second tobacco type to cover the distance between the weighing conveyor 2014 and the blending unit 2004. This insures that, despite the fact that the rate of tobacco throughput in the conveyor lines 2001,2002 upstream of the feeder 2011 and weighing conveyor 2014 might fluctuate for reasons which cannot be foreseen (for example, due to the characteristics of processing apparatus 2006 to 2009), the ratio of the two tobacco types in the blending unit 2004 remains unchanged. A delay or time-lag unit which can be used in the blending machine of FIG. 1 is shown in FIGS. 13 and 14.

The rate at which the feeder 2011 supplies tobacco to the weighing conveyor 2012 depends on the rate of tobacco advance through the weighing conveyor 2014. In other words, the rate of tobacco flow in the path defined by the conveyor line 2002 controls the rate of tobacco flow in the path defined by the conveyor line 2001. The weighing conveyor 2014 controls the proportioning unit 2010 which latter, in turn, controls the amounts of the first tobacco type downstream of the last processing apparatus in the conveyor line 2001. Thus, any unforeseen fluctuations in the rate of feed of the first tobacco type can be compensated for ahead of the blending unit 2004, especially since the feeder 2011 can store tobacco to compensate for eventual interruptions in delivery from the processing apparatus 2006. The conveyor 2014 is a rated value setting means for the proportioning unit 2010.

FIG. 2 is a flow sheet illustrating in diagrammatic form a machine for blending three tobacco types, for example, Burley, Oriental and Virginia tobacco. This machine comprises three conveyor lines 2020, 2021 and 2022 which deliver the respective tobacco types to a blending unit 2024 installed in a common conveyor line 2023. The numerals 2025 and 2031 denote processing apparatus the first of which is installed in the common line 2023 downstream of the blending unit 2024. The apparatus 2026 and 2027,2029 and 2030,2028 and 2031 are respectively installed in the conveyor lines 2020, 2021 and 2022. Two proportioning or metering units 2032 and 2033 are installed in the lines 2020 and 2022, and each thereof is analogous to the proportioning unit 2010 of FIG. 1. Their automatic feeders, weighing or metering conveyors and regulators or speed changers are respectively denoted by the numerals 2035 and 2036, 2037 and 2038, 2039 and 2040. The conveyor line 2021 accommodates a weighing conveyor 2034 which is located upstream of the processing apparatus 2029,2030 and sends signals to the regulators 2039,2040 in the same way as described in connection with the weighing conveyor 2014 and regulator or speed changer 2013 of FIG. 1. The nature of processing apparatus 2029,2030 in the conveyor line 2021 is assumed to be such that these apparatus do not cause any unforeseen fluctuations in the rate of delivery of the respective tobacco type. The apparatus 2029 and 2030 are the sole processing apparatus for tobacco which is conveyed by the line 2021, and it will be seen that the weighing conveyor 2034 is located at the receiving end of this line 2021. For example, the line 2021 can receive tobacco from hogsheads or bales. Signals transmitted by the weighing device 2034 .will control the rate at which the blending unit 2024 receives tobacco from the conveyor lines 2020 and 2022. The connections between the weighing conveyor 2034 and regulators or speed changers 2039,2040 respectively accommodate adjustable auxiliary delay or time- lag units 2043, 2044 which comprise travelling magnetic tapes serving to record impulses furnished by the weighing conveyor 2034. Reference may be had to FIG. 3 in the Pat. No. 3,419,015 to Wochnowski. The recordings are reproduced with a requisite delay or speed changers 2039,2040. In order to compensate for remaining differences in time required for travel of tobacco types to the blending unit 2024, the lines 2021,2022 respectively accommodate adjustable delay or time- lag units 2041, 2042 which are analogous to the delay units 2015,2016 of FIG. 1. The delay units 2041-2044 are set in such a way that the ratio of three tobacco types reaching the blending unit 2024 remains constant.

In the machine of FIG. 2, the rate atwhich the conveyor line 2021 supplies tobacco to the blending unit 2024 controls the rate at which the blending unit receives tobacco from the conveyor lines 2020 and 2022. Each of the feeders 2035,2036 is preferably arranged to accommodate a variable supply of the respective to bacco type.

The flow of sheet of FIG. 3 illustrates in diagrammatic form a third blending machine which comprises three conveyor lines 2050,2051 and 2052 serving to feed three tobacco types to a common conveyor line 2053 accommodating a blending unit 2054. The numerals 2055 to 2062 denote processing apparatus each of which can subject the respective tobacco type to a different treatment. Of course, two or more processing apparatus can subject tobacco to the same form of treatment. This machine further comprises three proportioning or metering units 2063,2064,2065 which are respectively installed in the lines 2051,2052 and 2050. The construction of each of these proportioning units is the same as that of the proportioning unit 2010 in the machine of FIG. 1. The processing apparatus 2062 is installed in the conveyor line 2051 downstream of the respective proportioning unit 2063. The other two proportioning units 2064,2065 are located downstream of the respective processing apparatus 2056,2057 and 2059,2060. The processing apparatus 2062 operates in the same way as the apparatus 2029,2030 of FIG. 2, i.e., it does not cause any unforeseen fluctuations in the rate at which the corresponding tobacco type is caused to pass therethrough and on toward the blending location. This apparatus 2062 serves to send signals to the regulator or speed changer 2066 of the proportioning unit 2063 in the conveyor line 2051. The weighing conveyor 2067.0f the proportioning unit 2063 is connected with the threeregulators or speed changers in the same way as described in connection with the weighing conveyor 2034 of FIG. 2. The lines 2050 and 2052 respectively accommodate delay or time- lag units 2068 and 2069.

The proportioning unit 2063 insures thatthe processing apparatus 2062 invariably receives a desired amount of tobacco per unit of time. Its weighing conveyor 2067 controls the regulators of the proportioning units 2064,2065 in conveyor lines 2052,2050 .to insure that the ratio of the three tobacco types remains at least substantially unchanged.

Referring now to FIG. 4, this illustration is a flow sheet of a fourth blending machine including three conveyor lines 2070, 2071, 2072 which deliver three tobacco types to a common conveyor line 2073 accommodating a blending means or blending unit 2074. The numerals 2075 to 2081 denote processing apparatus in the lines 2070-2073. The apparatus 2075 to 2080 are the sole processing means for the tobacco types which advance in the conveyor lines 2070-2072. The lines 2070-2072 respectively accommodate adjustable first proportioning or meter- units 2082,2083,2084 which are located upstream of the associated processing apparatus 2075-2076,2077-2078, 2079-2080 and second proportioning or metering units 2085,2086,2087 which are located downstream of the associated processing apparatus. Each of the proportioning units 2082-2087 is analogous to the proportioning unit 2010 in FIG. 1. The proportioning units 2082-2084 are connected to each other in such a way that the weighing or measuring conveyor 2088 of the proportioning unit 2083 sends signals to the three regulators or speed changers. Analogously, the weighing or measuring conveyor 2089 of the proportioning unit 2086 sends signals to the regulators or speed changers of the units 2085-2087. The lines 2070,2072 respectively accommodate delay or time- lag units 2090,2091 which are located downstream of the proportioning units 2085, 2087 and perfomi the same functions as the units 2015, 2016 of FIG. 1. The first three proportioning units 2082-2084 insure that the desired ratio between the three tobacco types is established, to a considerable extent, at the time when such tobacco types enter the respective conveyor lines. The second proportioning units 2085-2087 serve to compensate for unforeseen fluctuations in the rate of tobacco feed due to peculiarities and/or malfunction of processing apparatus 2075-2080.

FIG. 5 illustrates in greater detail a blending machine with analog speed changer circuitry which is adapted to provide the flow patterns, etc., similar to that indicated in FIG. 1. The first conveyor line 3 includes endless belts 1, 1A, 1B and 32, and the second conveyor line 4 comprises endless belts 2, 2A, 31, 31A, 318. The common conveyor line comprises an endless belt 34. A blending unit is shown at 33, and the second conveyor line 4 includes a proportioning unit 41 having a weighing conveyor 43 and an automatic feeder 42.

The belt 32 cooperates with the weighing conveyor 40 to activate the same and the speed changer 53 regulates the speed of the belt 32 through its power source, the motor 35. The belts 1 and 2 are driven by variablespeed electric motors 5 and 6, respectively. A regulator or speed changer for the motor 6 includes a bridge circuit 7 wherein the taps 10,11 are constituted by the sliding contacts or sliders of two potentiometers 8 and 9 connected in mirror symmetrical branches of the circuit 7. The sliders 10,11 are displaced synchronously with the movementof belts 1 and 2. The distances covered by these sliders are proportional to but shorter than the distances covered by the upper stringers of the belts 1 and 2. The speed-reducing transmissions for the sliders 10,11 are shown at 10,111 and each thereof receives motion from a roller or sprocket of the respective belt. The potentiometer 8 is connected in series with a delay or time-lag unit 12 which can be adjusted manually by an adjuster 13. Two other branches of the bridge circuit 7 respectively comprise symmetrically arranged fixed resistors 14,15. The connection to a current source includes terminals 16,17. The sliding contact or slider 19 of a variable resistor 18 in the diagonal or zero branch of the bridge circuit 7 is connected with the motor 6 for the belt 2. The RPM of the motor 6 varies as a function of voltage changes, i.e., as a function of changes in the setting of the slider 19. Thus, the bridge circuit 7 insures that the motor 6 rotates at a speed which is in a predetermined relation to the speed of the motor for the belt 1. This relation is offset in time due to the provision of delay or time-lag unit 12 and is adjustable by changing the position of the slider 19.

The belts 1 and 2 respectively deliver tobacco to belts 1A and 2A, and the belts 1A,2A respectively deliver tobacco to belts 1B,31. The directions in which the belts of F K]. 5 advance the respective tobacco types are indicated by arrows. The belts 1A,1B,32- ,2A,3l,3lA,3lB and 34 are driven by a common prime mover 35, e.g., an electric motor. This motor 35 also drives the blending unit 33; the latter may comprise a rotary drum which effects thorough intermixing of tobaccos coming from the belts 31B and 32. In the illustrated embodiment, the two tobacco types merge on the belt 32 immediately upstream of the blending unit 33.

The conveyor line 3 accommodates a composite processing apparatus 30 which includes three tobacco cutting machines 37. These machines 37 receive stemmed tobacco (laminae) from the belt 1B and deliver shredded tobacco onto the upper stringer of the belt 32. Excess stemmed tobacco which cannot be processed by the cutting machines 37 is fed to a recirculating conveyor 36 which includes three endless belts 36a,36b,36cthe first of which receives stemmed tobacco from the belt 1B downstream of the inlet to the last cutting machine 37. The belt 360 returns such tobacco onto the belt 1B upstream of the first cutting machine 37. The belts 36a-36c are driven by the motor 35. The belt 36b is adjacent to a level sensing device 38 which includs a maximum level indicator and a minimum level indicator. This device 38 preferably comprises two light sources and two photoelectric receivers similar to those which will be described in connection with FIG. 8. The level sensing device 38 sends signals to a speed changer or regulator 39 for the motor 5 of the belt 1.

A weighing or metering conveyor 40 is associated with the belt 32 of the first conveyor line 3 to determine the rate of tobacco delivery by the belt 32 and to send signals to a speed changer or regulator 53 for the motor 35. The weighing conveyor 40 is a functional equivalent of the weighing conveyor 2014 in FIG. 1 and is located upstream of the point where the belt 31B discharges the second tobacco type onto the belt 32. The belt 32 is a feeder for the conveyor 40 and the speed changer 53 is the regulator for the feeder or belt 32.

The belt 1, motor 5, recirculating conveyor 36, speed changer 39 and level sensing device 38 together constitute a first proportioning unit 29 for tobacco which is being fed by the conveyor line 3. The recirculating conveyor 36 constitutes a feeder of the proportioning unit 29 and is arranged to accumulate on its belts 36a -36c a variable supply of tobacco leaf laminae for delivery to the blending unit 33 through the processing apparatus 30 and belt 32. The belt 1 and motor 5 constitute means for admitting to the recirculating conveyor or feeder 36 tobacco leaf laminae at a rate which is a function of the quantity of material on the belts 36a-36c, the determination of the supply of laminae on the belts 3611-360 being can'ied out by the level sensing device 38.

The parts 32,40, 53 constitute a second proportioning unit in the conveyor line 3 and the weighing conveyor 40 constitutes the measuring means of this second proportioning unit. Its function is to control the operation of the proportioning unit 41 in the conveyor line 4 as well as to simultaneously control the feeder (belt 32) of the second proportioning unit.

The second conveyor line 4 accommodates the aforementioned proportioning unit 41 which is a functional equivalent of the proportioning unit 2010 in FIG. 1 and includes the weighing conveyor 43 arranged to receive tobacco from the automatic feeder 42. The regulator or speed changer 44 of the proportioning unit 41 includes a signal generator 45 which receives impulses from the weighing conveyor 43. The feeder 42 is capable of storing tobacco and is driven by a variable-speed motor 46. The quantity of tobacco on the feeder 42 is detected by a level sensing device 47 which is preferably identical with the aforementioned level sensing device 38 of the proportioning unit 29. The maximum and minimum level indicators of the sensing device 47 are respectively connected with signal storing units 48,49. The numeral denotes a rated value setting device which is adjustable by an adjuster 51. The rated value setting device 50 is connected with an averaging circuit 52 for the variable-speed drive motor 46 of the feeder 42 and includes a scale provided with, for example, ten graduations each corresponding to a different sequence of rates of tobacco flow. Each setting of the adjuster 51 corresponds to a different range of ten tobacco feed rates by the feeder 42, and only one rated value is selected at a time. The regulator 44 further comprises a timer which is arranged to permit passage of signals from the storing units 49,50 at predetermined intervals, for example, at SO-second intervals. if the minimum level indicator of the level sensing device 47 causes the storing unit 49 to send a signal via timer 55 and on to the rated value setting device 50, the output signal of the device 50 is changed to correspond to that for the nearest lower rate of tobacco feed. Such setting remains unchanged until after the elapse of the next 50- second interval. If, after the elapse of such interval, the timer 55 again transmits a signal coming from the storing unit 49 which receives signals from the minimum level indicator in the level sensing device 47, the signal coming from the device 50 is changed again to the nearest lower rate of tobacco feed, and so forth until the minimum level indicator of the sensing device 47 ceases to send signals via storing unit 49.

If the timer 55 transmits to the rated value setting device 50 a signal which is generated by the maximum level indicator of the level sensing device 47 and is transmitted by the storing unit 48, the output signal of the device 50 is changed to correspond to the nearest higher rate of tobacco feed. Such mode of operation repeats itself until after the storing unit 48 ceases to transmit signals at SO-second intervals. Depending on the momentary setting of the adjuster 51, the rated value setting device 50 adjusts the averaging circuit 52 for the motor 46 of the feeder 42. The signal which is transmitted to the averaging circuit 52 is a composite signal and is also influenced by the signal generator 45 associated with the weighing conveyor 43.

The position of the adjuster 51 need not be changed in response to admission of signals from the storing units 48,49. The arrangement is such that a first setting of the adjuster 51 causes the rated value setting device 50 to furnish ten different tobacco feed rates which change automatically in response to signals from the storing unit 48 or 49. If the adjuster 51 is reset, the device 50 will furnish different tobacco feed rates. The programming of 10 feed rates for each setting of the ad juster 51 is done in advance.

The averaging circuit 52 for the motor 46 of the feeder 42 in the proportioning unit 41 is further controlled by the speed changer or regulator 53 for the motor 35 in such a way that, when the weighing conveyor 40 detects a relatively low rate of tobacco feed on the belt 32, the speed of the feeder 42 is reduced accordingly, the vice versa. The exact construction of the timer 55, rated value setting device 50 and indexing device forms no part of the present invention.

The operation of the blending machine shown in FIG. 5 is as follows.

The bridge circuit 7 is adjusted in accordance with the desired average value of the ratio of the two tobacco types which are to be fed by the conveyor lines 3 and 4. The setting of the bridge circuit 7 is a function of the width of the belts l, 2 and of the thickness of tobacco layers on the upper stringers of such belts. The operators then start the motor 35 in a first step and the motors 5, 6 in a next-following step. The speed changer 39 of the first proportioning unit 29 in the conveyor line 3 becomes effective and causes the motor 5 to rotate at a high speed because it receives a signal from the minimum level indicator of the level sensing device 38. The bridge circuit 7 causes the motor 6 to drive the belt 2 at a high speed which is a function of the speed of the motor 5. ltis assumed that the belt 1 supplies stemmed tobacco and that the belt 2 supplies ribs or stems. The two tobacco types were treated separately during passage through one or more processing apparatus upstream of the belts l and 2. These belts may constitute the travelling bottom walls of boxes or bins which contain substantial supplies of the respective tobacco types. The belts 1,2 withdraw tobacco from the respective bins at a constant rate per unit of time; such rate depends on the speed of the motors 5 and 6. Stemmed tobacco drops at the discharge end of the belt 1 and is conveyed by the belts 1A,1B toward the inlets of the cutting machines 37 in the processing apparatus at a rate which is slightly in excess of the requirements of the cutting machines. Such slightly higher rate of tobacco feed is determined by the speed changer 39 because the latter continues to receive signals from the minimum level indicator of the level sensing device 38. Shredded tobacco issuing from the cutting machines 37 travels with the belt 32 and is weighed by the conveyor 40 prior to reaching the blending unit 33.

The surplus of stemmed tobacco which cannot enter the cutting machines 37 continues to travel with the upper stringer of the belt 1B and is transferred onto the first belt 36a of the recirculating conveyor 36. If the surplus of stemmed tobacco is substantial, the maximum level indicator of the level sensing device 38 sends a signal to the speed changer 39 and the latter reduces the speed of the motor 5 for the belt 1. The bridge circuit 7 then reduces the speed of the motor 5 resulting in a greatly reduced feed of stemmed tobacco. The surplus which is recirculated by the conveyor 36 is reduced to such an extent that the speed changer 39 receives a signal from the minimum level indicator of the level sensing device 38 and increases the speed of the motor 5.

When the motor 5 is started, the belt 1 immediately begins to convey stemmed tobacco toward the belt 1A. However, the motor 6 is started with a certain delay following starting of the motor 5, and such delay is determined by the delay or time-lag unit 12 in the bridge circuit 7. The adjuster 13 will adjust the delay unit 12 in such a way that the resulting delay plus the time required by successive increments of ribs to travel from the belt 2 to the belt 32 of the conveyor unit 4 equals the time required by successive increments of tobacco to advance from the belt 1 to the point where shredded tobacco mixes with the ribs coming from the belt 31B. Due to the provision of cutting machines 37, tobacco which is fed by the belt 1 requires more time to reach the point where its shredded particles mix with tobacco ribs.

Ribs which are fed by the conveyor belt 31A can pass V through the proportioning unit 41 at a rate which is determined by the regulator or speed changer 44. Such ribs then mix with shredded tobacco on the belt 32 and are finally blended with shredded tobacco in the blending unit 33. In other words, the blend which is advanced by the common conveyor belt 34 contains a mixture of ribs and tobacco shreds in a predetermined ratio.

1f the proportioning unit 41 delivers ribs at a relatively high rate per unit of time, the ratio of ribs to tobacco shreds in the blending unit 33 increases provided, of course, that the rate of tobacco feed by the belt 32 remains unchanged or decreases. The reverse occurs if the proportioning unit 41 reduces the rate at which the weighing conveyor 43 delivers ribs to the belt 318. Such changes in the ratio of ribs to shredded tobacco reflect fluctuations in the rate of delivery of the conveyor units 3 and 4. However, the ratio of ribs to shredded tobacco can change for other reasons too. All such fluctuations in. the ratio of ribs to shredded tobacco are reduced or eliminated by the weighing conveyor in the conveyor line 3 and by the proportioning unit 41 in the conveyor line 4. Rapidly occuring fluctuations in the rate at which the belts 1 and 2 supply the respective tobacco types are often due to the manner in which the respective tobacco types are stacked or arrayed on the upper stringers of the belts 1 and 2 and/or in the bins which furnish tobacco to these belts. Furthermore, fluctuations in the rate at which the belts 1 and 2 supply tobacco types can also develop due to peculiarities of processing apparatus which treat stemmed tobacco and ribs prior to admission into the respective bins. The effect of such rapidly occurring fluctuations can be readily reduced or eliminated by the machine of FIG. 5 so that, at the very worst, the ratio of shredded tobacco to ribs in the blending unit 33 will change very slowly. The magnitude of fluctuations of the ratio of tobacco shreds to ribs can be se' lected in advance by appropriate adjustment of the rated value setting device through the intermediary of the adjuster 51.

Fluctuations which are due to irregularities in the operation of the cutting machines 37 cannot affect the ratio of ribs to shredded tobacco in the blending unit 33. Such fluctuations merely cause fluctuations in the rate at which the blend advances with the upper stringer of the belt 34 because the weighing conveyor 40 controls the regulator or speed changer 44 for the proportioning unit 41 in the conveyor line 4 in the same way as described for the weighing conveyor 2014 and regulator or speed changer 2013 of FIG. 1. In other words, the weighing conveyor 40 measures the quantity of tobacco shreds and causes the proportioning unit 41 to feed ribs at a rate which remains a function of the rate of delivery of shreds to the blending unit 33.

As stated before, the delay or time-lag unit 12 of the bridge circuit 7 causes the motor 6 to drive the belt 2 with a certain delay following starting of the motor for the belt 1. Furthermore, the delay unit 12 causes the motor 6 to change its speed with a delay following any changes in the speed of the motor 5.

The machine of FIG. 5 is clearly analogous to the machine represented by the flow sheet of FIG. 1 with the exception that the proportioning unit 29 regulates the rate of tobacco delivery toward the processing apparatus 30 which corresponds to the apparatus 2008 and/or 2009 of FIG. 1. The weighing conveyor 2014 of FIG. 1 corrsponds to the conveyor of FIG. 5, and the proportioning unit 2010 of FIG. 1 corresponds to the unit 41 of FIG. 5. The feeder 2011, weighing conveyor 2012 and regulator or speed changer 2013 of FIG. 1 respectively correspond to the feeder 42, conveyor 43 and regulator or speed changer 44 of FIG. 5. The conveyor line 4 of FIG. 5 does not contain any processing apparatus such as would correspond to the apparatus 2006 and/or 2007 or FIG. 1.

Of course, the time-lag or delay unit 12 of FIG. 5 is needed only if the time required by successive increments of ribs to cover the distance from the belt 2 to the discharge end of the belt 31B is less than the time required by tobacco discharged from the belt 1 to reach the point where it mixes with ribs on the belt 32. The motor 6 will be arrested with a delay following stoppage of the motor 5, and such delay is again determined by the delay unit 12 in the bridge circuit 7.

The aforedescribed mode of operation of the motor 6, namely, that changes in its speed take place with a certain delay following changes in thespeed of the motor 5 constitutes an optional feature of the present invention. It is equally possible to construct the bridge circuit in such a way that it merely causes the motor 6 to start and to stop simultaneously with the motor 5. Such modified blending machine is shown in FIG. 6 which illustrates only those parts of the modified machine that are necessary for full understanding of its operation. The belts 101,102 of the two conveyor lines 103, 104 and the motors 105, respectively correspond to the parts 1,2,3,4 and 5,6 of FIG. 5, The bridge circuit 107 constitutes a speed changer for the motor 106 of the belt 102 but does not control the starting and stoppage of this motor. The speed reducing transmissions for the sliders 110,111 are shown at 101a, 101b and the elements 108-111, 114, 115, 118, 119 of the bridge circuit 107 are functional equivalents of sim ilarly numbered elements in the bridge circuit 7 of FIG. 5. The delay or time-lag unit 12 of FIG. 5 is replaced by a delay or time-lag unit 160 which is connected between the transmission 101a and the motor 106. The delay unit 160 may be adjusted by the manually operable adjuster 161, and this delay unit serves to start the motor 106 with a delay which has been selected in advance by the adjuster 161. The rotational speed of the motor 106 is adjusted by the bridge circuit 107 in the same way as described in connection with FIG. 5 but without any delay, i.e., all changes in speed of the motor 106 coincide with corresponding changes in speed of the motor 105. If the motor 105 is arrested, the motor 106 continues to run at a preselected basic speed. The means for arresting the motor 106 includes a detector or scanner 162 which is mounted adjacent to the belt 102 or 102A and opens the circiut of the motor 106 by conventional means such as a relay 163 when it detects that the respective belt is free of ribs. The detector 162 is preferably located in the path of ribs which are being showered from the discharge end of the belt 102 onto the upper stringer of the belt 102A.

FIG. 7 illustrates a digital speed changer circuit 67 for regulating the ratio at which the belts 61,62 of two conveyor lines feed two tobacco types, for example, stemmed tobacco and tobacco ribs. The belts 61,62 are respectively driven by variable-speed electric motors 65,66 and the regulator or speed changer for the motor 65 is-shown at 99. This speed changer 99 corresponds to the speed changer 39 of FIG. 5. The edge portions of the belts 61,62 are respectively provided with equidistant reflectors 70,71 which are scanned by photoelectric detectors 72,73. The detector 72 comprises a light source 74 which directs a beam of light against successive reflectors and an electronic receiver 77 whose output is connected with a sum and difference counter circuit 79 of conventional design. The detector 73 comprises a light source 76 which directs a beam of light against successive reflectors 71, and the thus reflected light impinges upon an electronic receiver 78 whose output is also connected with the counter circuit 79. The two inputs of the counter circuit 79 are shown at a and b and the output 0 of this counter circuit is connected with a signal amplifier 80 which regulates the speed of and starts the motor 66 for the belt 62. Signals received at the input a from the detector 72 cause the counter circuit 79 to add a digit, and signals received at the input b cause this counter circuit to deduct a digit. The difference between the series of signals received at the inputs a and b is translated into a positive or negative signal which is transmitted by the output c and controls the signal amplifier 80. The output of the detector 72 is further connected with an adjustable counter circuit 81 which causes a switch 82 to arrest the motor 66 in response to reception of a predetermined number of signals from the receiver 77.

The operation of the blending machine which embodies the structure of FIG. 7 is as follows.

In the first step, the counter circuit 81 is adjusted to actuate the switch 82 in response to reception of a predetermined number of signals from the detector 72, i.e., the counter circuit 81 will determine the overall length of the tobacco layer which is to be fed by the belt 62. The motor 65 is started and the receiver 77 transmits signals to the counter circuits 79 and 81. The number of successive signals received at the input a of the counter circuit 79 increases rapidly and the latter then causes the signal amplifier 80 to start the motor 66 for the belt 62. The reflectors 71 are set in motion and the receiver 78 sends to the input b a series of signals which influence the speed of the motor 66 so that the ratio of speeds of the belts 61,62 remains within a predetermined range. Fluctuations in the speed of the belt 61 bring about immediate changes in the speed of the belt 62 because the output signal of the counter circuit 79 is a function of the number of signals received at the inputs a and b. Furthermore, the counter circuit 81 in sures that the belt 62 is arrested after having delivered a predetermined quantity of tobacco.

FIG. 8 illustrates a portion of a further blending machine which includes a conveyor line comprising an endless belt 222 located downstream of a proportioning unit corresponding to the unit 2010 of FIG. 1, to the unit 2032 of FIG. 2, or to the unit 41 of FIG. 5. This proportioning unit comprises a weighing conveyor 210 which receives tobacco from a feeder including two endless belts 202,224, and a speed changer or regulator including an averaging circuit or junction 239, a variable-speed motor 250-for the belts 202,224, and a composite signal amplifier assembly 211 for the motor 250. The belt 202 serves to carry a variable supply of tobacco, and the belt 224 has an upwardly inclined upper stringer which receives tobacco from the upper run of the belt 202 and cooperates with rotary refuser wheels 227 to discharge an equalized tobacco layer onto the upper stringer of the weighing conveyor 210. The conveyors 210,222 are driven by a motor 207 which is controlled by a manually adjustable speed changer 228.

The quantity of tobacco stored on the belt 202 of the automatic feeder is scanned by a level sensing device 201 which includes a minimum level indicator 231, a maximum level indicator 232 and two signal storing units or bins 237,238.

The signal amplifier assembly 211 for the motor 250 includes a preamplifier 248 and a second amplifier 249, described below. The weighing conveyor 210 is connected with a signal generator 209 whose output is connected to the circuit averaging junction 239. This junction compares signals coming from the storing units 237,238 with signals coming from the signal generator 209 and from a rated value setting device 208, and sends signals to the preamplifier 248 of the signal amplifier assembly 211. The rated value setting device 208 comprises a potentiometer 240 whose slider 241 is connected with the junction 239. The potentiometer 240 can constitute the signal generator associated with a weighing conveyor in another conveyor line of the blending machine. With reference to FIG. 2, the potentiometer 240 could be adjusted by signals received from a weighing conveyor corresponding to the weighing conveyor 2034, it being assumed that the weighing conveyor 210 of FIG. 8 corresponds to the weighing conveyor 2037 of FIG. 2. If the weighing conveyor 210 of FIG. 8 is to replace the conveyor 2012 of FIG. 1, the potentiometer 240 could be adjusted by the weighing conveyor 2014.

The minimum level indicator 231 of the level sensing device 201 above the belt 202 comprises a light source 234 and a photosensitive receiver 235 which is connected to the input a of the storing unit 237 and to the input b of the storing unit 238. The maximum level indicator 232 comprises a light source 233 and a photoelectric receiver 236 connected to the input b of the storing unit 237 and to the input a of the storing unit 238. Signals transmitted to the inputs a of the storing units 237,238 cause these units to transmit signals to the circuit averaging junction 239, and signals received at the inputs b of the storing units 237,238 cause these units to erase the previously received signals. Such signal storing units are known and, therefore. the exact construction of the units 237,238 forms no part of the present invention. The circuit averaging junction 239 regulates the throughput of tobacco (quantity per unit of time).

The minimum level indicator 2311 sends a signal when the receiver 235 is free to receive light from the source 234. The maximum level indicator 232 sends a signal when the tobacco on the belt 202 interrupts the light beam between the source 233 and receiver 236. If the supply of tobacco on the belt 202 shrinks to such an extent that the light beam issuing from the source 234 is free to reach the receiver 235, the storing unit 237 sends to the junction 239 a signal which is added to the signal coming from the potentiometer 240 of the rated value setting device 208. The unit 237 stores such signal from the receiver 235 and continues to send an appropriate signal to the junction 239 until the signal is erased in response to reception of a signal at the input b, such signal being generated by the maximum level indicator 232 when the supply of tobacco on the belt 202 rises so that the accumulated tobacco interrupts the light beam coming from the source 233 and normally impinging upon the receiver 236. Of course, and when the receiver 235 sends a signal to the input a of the storing unit 237, it also sends a signal to the input 12 of the storing unit 238 whereby the latter ceases to send signals to the junction 239, i.e., this junction can receive a signal from the storing unit 237 and 238 but never from both storing units at the same time.

When a signal coming from the receiver 236 of the maximum level indicator 232 erases the signal from the storing unit 237, the storing unit 238 begins to transmit a signal to the junction 239. Such signal is different from the signal transmitted by the storing unit 237 so that the speed of the motor 250 is then changed accordingly.

Signals transmitted by the storing units 237,238 are opposed by signals produced by the signal generator 209. This signal generator comprises a potentiometer 243 having a slider 242 which is connected to the junction 239. The weighing conveyor 210 comprises a vertically movable platform 213 which is connected with the slider 242 by a linkage 244 having a pivot 245. The slider 242 is permanently biased to one end position by a return spring 246. The shaft of the slider 242 is shown at 247. The potentiometer 243 may be provided with a graduated scale and the slider 242 may be used to operate a pointer which moves in front of the scale to allow for visual observation of measurements carried out by the weighing conveyor 210.

The second amplifier 249 of the signal amplifier assembly 211 comprises control coils 249a,249b which convey currents whose strength is a function of signals transmitted by the storing units 237,238. Consequently, the working coils 2490,2491! will provide different voltages for the motor 250 which is a dc motor and whose speed is a function of such changes in voltage. The arrangement is such that the belt 202 continues to accumulate tobacco until the: maximum level indicator 232 sends a signal to the storing unit 238 and that the supply of tobacco on the belt 202 thereupon decreases until the minimum level indicator 231 sends a signal to the storing unit 237. In other words, the supply of tobacco on the belt 202 fluctuates between a minimum and a maximum value but invariably remains within a preset range.

In many instances, different tobacco types require very long or very short intervals ot advance from the respective source to the blending location. The length of such intervals will depend on the type of tobacco, on the capacity of processing apparatus which are used in treatment of tobacco, on the construction of the conveyor lines, on the number of processing apparatus in a conveyor line, and on certain other factors. FIGS. 9 to 12 illustrate blending machines which are constructed and assembled with a view to compensate for such differences in conveying times.

Referring to FIG. 9, there is shown a portion of a blending machine which comprises a first conveyor line 1001 for Virginia tobacco and a second conveyor line 1071 for Oriental tobacco As stated before, preliminary treatment of Oriental tobacco is much simpler and consumes less time than the treatment of other tobacco types. The conveyor line 1001 for Virginia tobacco comprises three sections 1002,1003,1004. The median section 1003 comprises an endless receiving belt 1084 which is a take-off belt and serves to advance tobacco from the processing apparatus in the section 1003 to apparatus in the section 1004. This median section 1003 comprises three portions 1003a, 1003b, 10030 which respectively include endless belts 1088, 1089 and 1091. The belt 1091 serves to feed tobacco into a processing apparatus 1006 which is used to mix tobacco with casing or flavoring solution. A similar apparatus is disclosed in the aforementioned Pat. No. 3,419,015 to Wochnowski. The output of the processing apparatus 1006 (hereinafter calld mixer for short) descends onto the aforementioned discharging belt 1084 and is advanced toward one or more further processing apparatus in the section 1004. The drum 1006d of the mixer 1006 is rotatable about an axis which is slightly inclined with reference to a horizontal plane and is driven by a variable-speed motor 1007. This motor 1007 also drives the belt 1091. The mixing zone in the interior of the drum 1006d receives casing from the atomizer nozzle of a conduit 1006a which is connected with a tank 1006b and contains a variabledelivery pump 10060. The arrow 1008 indicates the direction in which the casing flows when the pump 1006c is in operation. The conduit 1006a further contains an adjustable metering valve 1009 which is regulated by a speed changer or regulator 1011 for the motor 1007. The speed changer 1011 is further connected with a moisture detector 1012 which is installed in or adjacent to the discharging belt 1084 and controls the adjustment of valve 1009 as well as the speed of the motor 1007. The moisture detector 1012 determines the moisture content of tobacco which has been mixed with casing and, therefore, the measurement carried out by detector 1012 is indicative of the intensity or thoroughness of mixing action which takes place in the drum 1006d. The moisture detector 1012 comprises capacitor means 1012a forming part of an oscillator circuit (not shown) whose frequency may be changed periodically by a non-illustrated variable capacitor. The variations in high-frequency oscillations are induced by changes in moisture content and are measured to determine such moisture content.

The supply conveyor 1091 which delivers tobacco to the drum 1006d of the mixer 1006 is associated with a detector or sensor 1013 whichdetermines the throughput of tobacco and is connected with a signal generator 1014. The detector 1013 may be constituted by a photoelectric cell assembly which sends a signal when the conveyor belt 1091 ceases to deliver tobacco. The signal generator 1014 has a first output 1016 which sends a signal when the detector 1013 produces a signal indicating that the delivery of tobacco by the belt 1091 is terminated, and a second output 1017 which sends signals in the absence of a signal from the detector 1013. The signal generator 1014 may comprise a lightsensitive electronic receiver. The outputs 1016,1017 are respectively connected with two amplifiers 1018,1019 whose outputs are connected with a twoway switching device 1021. The switching device 1021 has a single output which is connected with the speed changer or regulator 1011. A third input of the switching device 1021 is connected with a rated value setting device 1022 which can be set by a manually operated adjuster 1023. The rated value setting device 1022 controls the speed changer 1011. The fourth input of the switching device 1021 is connected with an arresting switch 1024 which can arrest the motor 1007 simultaneously with closing of the valve 1009.

The switching device 1021 can be moved to two positions. In one of its positions, it connects the rated value setting device 1022 with the speed changer 1011 when the signal generator 1014 sends signals through the amplifier 1019 (i.e., when the belt 1091 delivers tobacco to the drum 1006d). In the other position of the switching device 1021, the arresting switch 1024 is connected in circuit with the speed changer 1011 and the latter arrests the motor 1007 because the switching device 1021 receives a signal from the signal generator 1014 via amplifier 1018. The arresting switch 1024 then effects closing of the valve 1009.

The operation of the mixer 1006 is as follows.

When the detector 1013 determines that the belt 1091 does not supply tobacco into the drum 1006d, the signal generator 1014 sends a signal via amplifier 1018 and such signal causes the switching device 1021 to connect the speed changer 1011 in circuit with the arresting switch 1024 so that the valve 1009 is closed and the motor 1007 is at a standstill. Prior to admission of a fresh charge of Virginia tobacco to the belt 1091, the rated value setting device 1022 is set by the adjuster 1023 to insure that each increment of tobacco will be mixed with a predetermined amount of casing. When the freshly admitted charge (coming from the belt 1089 in the portion 100311 of the conveyor line section 1003) reaches the belt 1091, the detector 1013 sends a signal to the signal generator 1014 and the latter sends to the switching device 1021 a signal via output 1017 and amplifier 1019. It should be noted that the detector 1013, as seen in FIG. 9, is of necessity so positioned that it would react to the flow of particles into conveyor 1091 from the conveyor 1089. The switching device 1021 then connects the rated value setting device 1022 with the speed changer 1011 and the latter opens the valve 1009 and starts the motor for the drum 1006d. The arresting switch 1024 is then disconnected from the speed changer 1011. The throughput of the valve 1009 and the speed of the motor 1007 will depend on the setting of the rated value setting device 1022, and the motor 1007 continues to drive the belt 1091 and the drum 1006d until the detector 1013 sends a signal indicating that the charge of tobacco has been consumed. The arresting switch 1024 then stops the motor 1007 and effects closing of the valve 1009 in a manner as described above.

The portions 1003a and 10031) of the conveyor line section 1003 accommodate other processing apparatus. For example, and as shown in FIG. 9, the portion 1003b accommodates a stripping or destalking machine 1025a which is associated with a pneumatic separator 1025. A similar combination is disclosed, for example, in Pat. No. 3,265,209 granted to Wochnowski et al. on Aug. 9, I966. The portion 1003a accommodates a moistening apparatus 1026 for tobacco leaves. This apparatus is similar to the mixer 1006 with the exception that the atomizer nozzle of its conduit 1026a discharges water, steam or another suitable moistening agent.

The stripping machine 1025a comprises a rotary drum 1025b whose blades destalk tobacco leaves in co operation with a fixed basket and which is driven by a variable-speed motor 1025f. The mixture of tobacco leaf laminae and ribs issuing from the machine 1025a enters the housing 1025c of the separator 1025 wherein the ribs are segregated from laminae. The ribs drop onto a take-off belt 1025c and the laminae descend onto the aforementioned belt 1089. The separator 1025 comprises a closed pneumatic circuit which contains a suction fan 102511 driven by a motor 1025e. The hopper of the stripping machine 1025a receives moistened tobacco leaves from a conveyor belt 1083. The motors 1025e, 1025f can be started and arrested by a system of switches mounted on a control panel 1025g. This control panel receives signals from a detector or sensor 262 which is adjacent to the upper run of the belt 1083. If the detector 262 determines the presence of tobacco leaves on the belt 1083, it causes the switches on the contorl panel 1025 g to start the motors 1025e,1025f. The detector 262 also sends signals which disconnect the motors 1025a, 1025f from the source of electrical energy.

The component parts of the moistening apparatus 1026 in the portion 1003a of the conveyor line section 1003 are analogous to the parts of the mixer 1006 and are denoted by similar reference numerals. For example, the numerals 1026d, 1029,1031 respectively denote a rotary drum, an adjustable valve and a speed changer.

The second conveyor line 1071 for Oriental tobacco comprises three sections 1072,1073,1074. The first section 1072 merely contains a belt 1096 (or a series of belts) serving to deliver Oriental tobacco from a source to a belt 1097 in the section 1073. The belt 1097 supplies tobacco into the drum 107641 of a moistening apparatus 1076 which is similar to the moistening apparatus 1026 and mixer 1006. The drum 1076d is driven by a variable-speed electric motor 1077 which also drives the belt 1097 and is connected with a speed changer or regulator 1087. The control system of the moistening apparatus 1076 further includes a moisture detector 1082 which is adjacent to a discharging belt 1098 (serving to deliver tobacco to the section 1074) and is connected with an averaging circuit or junction 1081. The latter controls an adjustable metering valve 1079 in the conduit which admits water or steam into the mixing zone of the drum 1076d. The junction 1081 is further connected with the slider of a potentiometer 1092 forming part of a rated value setting device. The speed changer 1087 starts and arrests the motor 1077 in response to signals received from the detector 1013 in the section 1003 of the conveyor line 1001 for Virginia tobacco.

The processing apparatus 1006, 1025-1025a, 1026 and 1076 are started and arrested in automatic response to signals receivedfrom detectors 1013, 262, 1033, i.e., as a function of the tobacco feed. Of course, the travel of Virginia tobacco through processing apparatus 1006,1025-1025a, 1026 requires more time than the travel of Oriental tobacco through the single processing apparatus 1076. In order to avoid the utilization of bulky and costly intermediate magazines for Oriental tobacco upstream of the blending location where the conveyor lines 1001 and 1071 of FIG. 9 meet, the detector 1013 in the portion 1003c of the conveyor line section 1003 for Virginia tobacco controls the speed changer 1087 for the motor 1077 and belt 1097 of the processing apparatus 1076 for Oriental tobacco. The speed changer 1087 starts the motor 1077 when the detector 1013 senses the presence of Virginia tobacco on the belt 1091. Thus, the rate at which the discharging belt 1098 delivers Oriental tobacco from the section 11073 to the section 1074 of the conveyor line 1071 varies in the same way as the rate at which the belt 1084 delivers Virginia tobacco from the section 1003 to the section 1004 of the conveyor line 1001 despite the fact that preliminary treatment of Virginia tobacco consumes much more time than preliminary treatment of Oriental tobacco. The ratio of Virginia tobacco to Oriental tobacco can be selected in the same way as described in connection with FIGS. 5 to 7. The belts 1,2 of FIG. 5 would correspond to the belts 1084 and 1098 of FIG. 9.

Of course, a tobacco stream or mat will require a certain amount of time to advance from a detector to the associated processing apparatus. For example, a certain amount of time will elapse between detection of Virginia tobacco leaves by the detector 1033 in the portion 1003a of the conveyor line section 1003 of FIG. 9 and the entry of such leaves into the associated moistening apparatus 1026. Such time span can be accounted for or considered by arresting the respective processing apparatus with a delay corresponding to the time interval required by an increment of tobacco on the belt 1088 to advance from the detector 1033 into the mixing zone of the drum 102611. A suitable delay or time-lag unit 1020 associated with the detector 1013 is indicated schematically in the circuit of the processing apparatus or mixer 1006 of FIG. 9, and a second delay unit 1040 is shown in the circuit of the moistening apparatus 1026. The delay unit 1020 can be installed between the amplifier 1018 and the two-way switching device 1021 and is indicated by broken lines because it constitutes an optional feature of the blending machine. The same applies for the delay unit 1040. For example, the delay unit 1020 can be built into the speed changer 1011 for the motor 1007. It is clear that the circuits of the processing apparatus l025-1025a, and 1076 can be provided with analogous delay or time-lag units.

If the delay unit 1020 of FIG. 9 delays only the stoppage of the'motor 1007, the mixer 1006 will be in operation but will receive no tobacco during the interval required by tobacco shreds to advance from the detector 1013 to the mixing zone in the drum l006d. Such shortlasting dry run of the mixer 1006 does no harm.

In the blending machine of FIG. 9, the rated value setting device 1022 in the circuit of the mixer 1006 can be set by the adjuster 1023. The setting selected by the manually operated adjuster 1023 will be effective when the tobacco shreds enter the portion 10030 of the conveyor line section 1003. The setting of the device 1022 for a fresh charge of tobacco can be changed subsequent to transport of the preceding charge beyond the drum 1006d. If it is desired to process charges of different consistencies in rapid sequence, the time allotted for manual operation of various adjusters (1023,1043) will be rather short.

FIG. illustrates diagrammatically a blending machine wherein the processing apparatus can be properly reset or adjusted for processing of one or more fresh charges of tobacco while the preceding charge is still in the process of undergoing treatment on its way to the blending location. The setting for treatment of next-following charges does not affect the treatment of the running charge. In the diagram of FIG. 10, all such parts which are clearly analogous to or identical to the parts described in connection with FIG. 9 are denoted by similar reference numerals raised by 100. Thus, the mixer 1106 of FIG. 10 corresponds to the mixer 1006 of FIG. 9. The blending machine which is shown schematically in FIG. 10 further comprises a locking unit 1157 which is installed between the two-way switching device 1121 and the rated value setting device 1122. The output of the locking unit 1157 is connected with the amplifier 1119, and this locking unit 1157 comprises a timer 1158 adapted to be set by a manually operated adjuster 1159. The locking device 1157 also comprises a storing device 1161 for signals received from the rated value setting device 1122. The timer 1158 is connected between the amplifier 1119 and the storing device 1161, and the latter is connected between the rated value setting device 1122 and the two-way switching device 1121. The adjuster 1159 can set the timer 1158 and the latter counts time only when the belt 1191 delivers tobacco past the detector 1113. In 'other words, the timer 1158 determines only the length of the interval during which the mixer 1106 receives tobacco. Such interval is known in advance for a given quantity of tobacco. The adjuster 1159 sets the timer 1158 for the shortest possible interval which is required to complete the treatment of a known charge in the mixer 1106. When the signal generator 1114 sends a signal via output 1116 and amplifier 1118 to indicate that the delivery of tobacco is completed prior to elapse of the anticipated interval (setting of timer 1158 by adjuster 1159), such signal indicates that the operation of the machine is not satisfactory. The ma chine is then arrested prior to completed treatment of the charge. The manner in which a signal coming from the output 1116 and amplifier 1118 can arrest the mixer 1106 is the same as described in connection with FIG. 9. The same holds true for the manner in which a signal coming from the signal generator 11 14 via output connection 1117 and amplifier 1119 restarts the mixer 1106. The two-way switching device 1121 then receives signals from the signal storing device 1161 independently of the rated value setting device 1122 and sends signals to the speed changer or regulator 1111 for the motor 1107. The storing device 1161 blocks the passage of signals from the rated value setting device 1122 if such signals are different from those transmitted by the storing device 1161. The latter will cease to transmit signals upon elapse of the interval selected by the adjuster 1159 for the timer 1158 and upon reception from detector 1113 of a signal that a fresh charge of tobacco is being fed to the mixer 1106. The operation of the speed changer 1111 is then controlled by signals from the rated value setting device 1122 which can transmit the same signals as before or different signals, depending upon whether or not the adjuster 1123 was reset during the interval when the speed changer 1111 was receiving signals from the storing device 1161.

The timer 1158 is reset to zero when the speed changer 1111 receives signals from the rated value setting device 1122 and begins to count a new interval which can be the same as the previously counted interval or a different interval, depending on the shortest anticipated time required for processing of the charge which is being fed into the drum of the mixer 1106. The setting of the timer 1158 is carried out by the adjuster 1 159.

It will be seen that the rated values of signals which will control the speed changer 1111 during treatment of the next-following charge can be selected before a charge has completed its advance through the mixer 1106 and while the charge which travels through the mixer is treated in accordance with a recipe which might but need not be the same as the recipe for the next-following charge. In other words, the locking unit 1157 serves to program the blending machine for a future operation while the machine is in actual use. It is also possible to select in advance two or more future operations of the machine if the manually adjustable timer 1158 is replaced with a programmable timer. Also, the machine of FIG. 10 may be equipped with a counter 1063 (shown by broken lines) which can automatically stop the motor 1107 after elapse of a predetermined period of time selected by a suitable adjuster 1064. The counter 1063 is connected directly to the speed changer 1111 and its signal overrides the signals coming from the locking unit 1157. The counter 1063 is set in motion in automatic response to starting of the motor 1107 and interrupts its count if the operation of the mixer 1106 is interrupted. Signals to start, interrupt and restart the counter 1063 are furnished by the speed changer 1111.

FIG. 11 illustrates schematically a blending machine which comprises delay or time-lag devices serving to compensate for different times required by different tobacco types to reach the blending location and to compensate for times required by a given tobacco type to advance from a detector to the adjoining processing apparatus. The numerals 1203A, 1288, 1283 denote three endless belts forming part of a conveyor line for a given tobacco type. A processing apparatus 1226 is adjacent to the median belt 1288 and this apparatus is arranged to perform the same function as the moistening apparatus 1026 in the left-hand part of FIG. 9. A detector 1233 is adjacent to the belt 1288 upstream of the drum of the moistening apparatus 1226 which latter is driven by a variable-speed electric motor 1227. Two amplifiers 1238,1239 receive signals through output lines 1236,1237 of a signal generator 1234 which is connected with the detector 1233. The motor 1227 is regulated by a speed changer 1231 which, however, does not regulate the metering valve 1229. The latter is regulated by a separate regulator 1231A. The speed changer. 1231 is connected with a gate 1250 which is connected with a rated-value-setting device 1242. The regulator 1231A is connected with a delay or time-lag unit 1251, and a gate 1252. The rated value setting de vice 1253 for the regulator 1231A can be set by a manually operated adjuster 1254. The rated value setting device 1242 for the speed changer 1231 can be set by an adjuster 1243. The numeral 1244 denotes an arresting switch which can be connected with the speed changer 1231 to arrest the motor 1227. The switch 1244 can be connected in circuit with the motor 1227 through a gate 1255, a delay or time-lag unit 1256 and a control switch 1257. c

The valve 1229 can be closed through the intermediary of a delay or time-lag unit 1258 and a gate 1259 by an arresting switch 1260 which is analogous to the arresting switch 1244. A timer 1261 whose input is connected with the motor 1227 has three outputs connected with the delay or time- lag units 1251, 1256 and 1258.

The operation is as follows.

The adjusters 1243, 1254 will be manipulated to set the rated value setting devices 1242 and 1253 in order to select rated values for the speed changer 1231 and regulator 1231A. The signals coming from devices 1242,1253 can reach the speed changer 1231 and regulator 1231A only when the respective gates 1250,1252 are open. The regulator 1231A will receive signals with a delay determined by the delay or time-lag unit 1251.

The zero or shut-off signals coming from the arresting switches 1244, 1260 will reach the speed changer 1231 and regulator 1231A only when the respective gates 1255,1259 are open. Such signals will be delayed by the delay units 1256 and 1258.

The delay unit 1251 is set for a delay or interval l, which is required by an increment of tobacco to advance from the detector 1233 to the inlet of the moistening apparatus 1226. The delay unit 1258 is set for an interval which is required by tobacco to cover the distance from the detector 1233 to the moistening zone in the apparatus 1226, namely, to the zone where the tobacco comes in contact with water or steam issuing from one or more nozzles (not shown). The delay'unit 1256 is set for a delay or interval r, required by tobacco to travel from the detector 1233 to the discharge end of the belt 1288. The intervals ,1 and t, are functions of the speed of the motor 1227; therefore, the timer 1261 is connected with the motor 1227 and receives therefrom signals whose frequency is a function of the speed of the belt 1288 and the speed of the drum in the moistening apparatus 1226. The timer 1261 controls the delay units l25l,1256,1258 in such a way that the intervals t ,t ,t are functions of the frequency at which the timer receives impulses from the motor 1227.

The gates 1252,1259,1250 and 1255 are controlled by amplifiers 1238,1239 in such a Way that the gates 1255,1259 open only when the signal generator 1234 sends a signal through the output line 1236 and amplifier 1238, and that the gates 1250,1252 open only when the signal comes from the output line 1237 and amplifier 1239, i.e., when the detector 1233 detects the advance of tobacco on the belt 1288.

When the belt 1288 does not deliver tobacco, the detector 1233 causes the signal generator 1234 to send a signal through the output line 1236 and amplifier 1238 so that the gates 1255 and 1259 are open. The valve 1229 is closed by the arresting switch 1260 and a control switch 1262. The speed changer 1231 stops the motor 1227 in response to a signal from the arresting switch 1244 and control switch 1257.

If the belt 1203A thereupon admits tobacco to the belt 1288 (which is idle), the detector 1233 sends a signal which causes the gates 1255,1259 to close and the gates 1250,1252 to open. The control switches 1257,1262 are disconnected from the respective arresting switches 1244,1260 but this does not affectthe position of the valve 1229 which remains closed. The rated value setting device 1242 is connected with the speed changer 1231 because the gate 1250 is open whereby the speed changer 1231 starts the motor 1227 without delay at a speed determined by the rated value Setting device 1242. The speed changer 1231 turns off the control switch 1257. The timer 1261 receives from the speed changer 1231 impulses :at a frequency which is a function of the speed of the motor 1227. The belt 1288 is driven by the motor 1227 and begins to deliver tobacco from the discharge end. of the belt 1203A toward the moistening apparatus 1226 while the valve 1229 continues to prevent admission of water or steam. Upon elapse of the interval signals from the rated value setting device 1253 can reach the regulator 1231A through the gate 1252 which is open. The regulator 1231A turns off the control switch 1262 and opens the valve 1229 to the extent determined by the rated value setting device 1253. The valve 1229 begins to admit water or steam which reaches the interior of the moistening drum shortly thereafter. During the interval which elapses while the moistening agent flows from the valve 1229 to the nozzle or nozzles in the drum of the processing apparatus 1226, tobacco reaches the nozzles (i.e., the interval t has elapsed) and the circuitry of FIG. 11 then remains in the just describedstate until the detector 1233 sends a signal which indicates the absence of tobacco on the belt 1288. Such signal closes the gates 1250,1252 and opens the gates 1255,1259. The speed changer 1231 and regulator 1231A are disconnected from the rated value setting devices 1242,1253 but they continue to control the speed of the motor 1227 and the position of the valve 1229 because they have stored the last signals from the devices 1242,1253. The motor 1227 continues to run and the valve 1229 remains open. The motor 1227 is stopped when the signal coming from the arresting switch 1244 and passing through open gate 1255 reaches the control switch 1257 with a delay determined by the delay unit 1256. The valve 1229 is closed when the signal coming from the arresting switch 1260 through the. gate 1259 (which is open) reaches the control switch 1262. The delay unit 1258 permits the signal coming from the arresting switch 1260 to reach the control switch 1262 with a delay i.e., when the last increment of the charge has covered the distance from the detector 1233 to the spray nozzles in the drum of the moistening apparatus 1226. The control switch 1262 erases in the regulator 1231A the last signal from the rated value setting device 1253.

When the interval 2 has elapsed, the entire charge has been conveyed beyond the belt 1288 and the delay unit 1256 permits the signal from the arresting switch 1244 to reach the control switch 1257 which arrests the motor 1227 and erases in the speed changer 1231 the last signal from the rated value setting device 1242. The timer 1261 ceases to receive impulses from the motor 1227 so that the circuitry :is deenergized. The procedure is repeated in the above-described sequence when the detector 1233 detects the first increment of a fresh charge coming from the belt 1203A. The motor 1227 will be driven at a speed selected by the rated value setting device 1242 and the valve 1229 will open to the extent depending on the intensity of signals transmitted by the rated value setting device 1253. The devices 1242,1253 may but need not be reset by adjusters 1243,1254, depending on the type of charge and on the desired moistening of tobacco in the processing apparatus 1226.

In the machines represented by the diagrams of FIGS. 9 and 11, the rated value setting devices 1022,1042,l242,1253 can be adjusted after the respective regulators 1011,103l,l231,1231A receive the signal which indicates the end of the transport of tobacco. In the machine of FIG. 10, the rated value setting device 1122 can be adjusted before the speed changer or regulator 1111 receives the signal which indicates the end of the transport of tobacco.

In many instances, the recipe (i.e., the rate at which a moistening or mixing apparatus admits water, steam, casing or flavoring solution to tobacco) must be changed from charge to charge. In the blending machines represented by the diagrams of FIGS. 9 to 11, this would entail adjustment of the respective rated value setting devices after completion or during processing of each successive charge. FIG. 12 illustrates schematically a portion of a blending machine wherein a series of adjustments of the rated value setting means can be scanned in a predetermined sequence so that two or more charges can be processed in accordance with a predetermine program even through the recipes for the charges are different. The parts shown in FIG. 12 are analogous to those described in connection with FIG. 9 and are denoted by similar reference numerals with 300 added to each numeral. The structure of FIG. 12 differs from that of FIG. 9 mainly in that the rated value setting device 1022 (and the adjuster 1023) is replaced with a more sophisticated circuit including a four-pole step-by-step switching'device 1350 having a central contact connected with one input of a twoway switching device 1321. The four poles of the switching device 1350 are connected with four rated value setting devices 1351,1352,l353,1354. Each of the devices 1351-1354 can be set by one of four adjusters 1355,1356,1357,1358, and each of these-devices corresponds to the device 1022 of FIG. 9. The numeral 1359 denotes a timer which can be set by an adjuster 1360 and is connected between the amplifier 1319 and switching device 1350. The timer 1359 corresponds to the timer 1158 of FIG. and serves to determine the duration of signals coming from the amplifier 1319 (when the belt 1391 feeds tobacco to the processing apparatus 1306) as well as to compare such signals with signals stored therein in response to setting by the adjuster 1360. If the signal coming from the output line 1317 and amplifier 1319 indicates that the interval of feed of a given charge exceeds the anticipated interval (setting by the adjuster 1360), the timer 1359 is activated and the next tobacco signal from the amplifier 1319 is transmitted to the switching device 1350 to reset the latter so that the next-following rated value setting device (e.g 1352) sends signals on to the speed changer or regulator 1311 for the motor 1307 and valve 1309. At the same time, the timer 1359 is inactivated (insofar as resetting of the device 1350 is concerned) and is reset to zero so that it can start to count the duration of the next interval (delivery of the next tobacco charge into the processing apparatus 1306).

The adjuster 1360 selects the interval which is anticipated for processing of a charge. The just described mode of operation is repeated as often as needed but not more than two more times because the operating means for the apparatus 1306 of FIG. 12 has four rated value setting devices 1351-1354. The signal to arrest the motor 1307 and to close the valve 1309 is generated in the same way as described in connection with operation of the processing apparatus 1006 in FIG. 9. A moisture detector is shown at 1112 in FIG. 10, at 1208 in FIG. 11, and at 1312 in FIG. 12, respectively, and in each instance the function of the moisture detector and its cooperation with the valves 1109,1229 and 1309, respectively, is the same as that pertaining to the moisture detector 1012 and the valve 1009 appearing in the upper right-hand portion of FIG. 9.

In the blending machines which embody the structures shown in FIGS. 9-12, differences in time required for treatment of tobacco types in various processing apparatus are compensated for in response to signals received from strategically distributed detectors or sensors. Another possibility of compensating for such differences has been shown in FIGS. l-4 which respectively show delay or time-lag units 2015-2016, 2041-2042, 2068-2069 and 2090-2091. These delay units are disposed downstream of the respective processing apparatus and one thereof is illustrated in FIGS. 13 and 14.

The delay unit of FIGS. 13 and 14 comprises an elongated box or bin 401 having a superstructure 402 of rectangular outline and including the side walls of the bin. The superstructure 402 preferably consists of wood. The bottom wall of the bin 401 is constituted by the upper stringer of an endless conveyor belt 403 which is trained around rollers 404,405. The roller 405 can be driven by a d-c motor 406 which is connected with a source 408 of polyphase alternating current through the intermediary of a rectifier 407. The output voltage of rectifier 407 can be regulated by an adjuster 409. The output shaft of the motor 406 drives belts 412,413,423 which respectively rotate shafts 414,415,424 of rake wheels 416,417,425. The wheels 416,417,425 together form a withdrawing device 422 which moves tobacco from the bin 401. The latter receives tobacco from a supply conveyor 418 and the withdrawing device 422 feeds tobacco to a take-off belt 419.

In operation, the supply conveyor 418 delivers tobacco into the bin 401 and onto the upper stringer of the belt 403. This belt advances tobacco toward the withdrawing device 422 which feeds tobacco onto the take-off belt 419. The speed of the belt 403 can be varied infinitely by the adjuster 409, i.e., the belt 403 constitutes with parts 406-409 an adjustable delay or timelag unit.

Each of the delay units 2015,2016 shown in FIG. 1 can comprise a belt 403 and the speed of each of these belts can be adjusted in such a way that the time required by increments of tobacco of the first type to advance from the proportioning unit 2010 to the blending unit 2004 is the same as the time required by increments of tobacco of the second type to travel from the weighing or measuring conveyor 2014 to the blending unit 2004.

The rate at which the conveyor 418 supplies tobacco into the bin 401 of FIGS. 13 and 14 depends on the setting of the proportioning unit. For example, the conveyor 418 of FIGS. 13 and 14' can correspond to the conveyor which forms part of the conveyor line 2001 in FIG. 1 to deliver tobacco from the weighing conveyor 2012 to the delay unit 2015. Y

As shown in FIG. 2, the conveyor line 2020 does not contain a delay unit. This is due to the fact that this conveyor line delivers tobacco at a rate which is less than the rate of tobacco delivery by lines 2021,2022. The delay units 2041,2042 in conveyor lines 2021,2022 insure that the average speed of tobacco delivery from the processing apparatus 2030 and weighing conveyor 2037 to the blending unit 2024 is the same as from the weighing conveyor 2037.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features which fairly constitute essential characteristics of the generic and specific aspects of our contribution to the art.

What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims:

1. In a machine for the treatment of tobacco or other fibrous material, particularly for conditioning, blending or changing the size of tobacco, a combination comprising conveyor means arranged to advance successive elongated charges of fibrous material along a predetermined path; detector means adjacent to a first portion of said path and arranged to respectively produce first and second signals in response to detection of the leading and trailing ends of successive elongated charges; treating means including at least one processing apparatus adjacent to a second portion of said path located downstream of said first portion and being activatable to treat the fibrous material of said charges and operating means for respectively activating and deactivating said processing apparatus in response to said first and second signals.

2. A combination as defined in claim 1, wherein said operating means includes time-delay means for delaying the activation of said processing apparatus in response to said first signals for intervals of time which elapse during transport of fibrous material from said first to said second portion of said path.

3. A combination as defined in claim 1, wherein said operating means includes time-delay means for delaying the deactivation of said processing apparatus in response to said second signals for intervals of time which elapse during transport of fibrous material from said first to said second portion of said path.

4. A combination as defined in claim 1, wherein said processing apparatus includes means for contacting the fibrous material in said second portion of said path with at least one treating medium.

5. A combination as defined in claim 1, wherein said processing apparatus comprises means for blending at least one different type of fibrous material with the fibrous material of said charges.

6. A combination as defined in claim 1, wherein said detector means includes photosensitive transducer means.

7. A combination as defined in claim 1, wherein said conveyor means comprises a plurality of discrete conveyors.

8. A combination as defined in claim 1, further comprising means for arranging successive charges on said conveyor means in a discontinuous stream.

9. A combination as defined in claim 1, wherein said treating means comprises a plurality of processing apparatus each of which is activatable and deactivatable by said operating means.

10. A combination as defined in claim 1, wherein said processing apparatus includes means for adding to said fibrous material a plurality of treating media and said operating means comprises means for selecting said treating media.

Claims (10)

1. In a machine for the treatment of tobacco or other fibrous material, particularly for conditioning, blending or changing the size of tobacco, a combination comprising conveyor means arranged to advance successive elongated charges of fibrous material along a predetermined path; detector means adjacent to a first portion of said path and arranged to respectively produce first and second signals in response to detection of the leading and trailing ends of successive elongated charges; treating means including at least one processing apparatus adjacent to a second portion of said path located downstream of said first portion and being activatable to treat the fibrous material of said charges and operating means for respectively activating and deactivating said processing apparatus in response to said first and second signals.

2. A combination as defined in claim 1, wherein said operating means includes time-delay means for delaying the activation of said processing apparatus in response to said first signals for intervals of time which elapse during transport of fibrous material from said first to said second portion of said path.

3. A combination as defined in claim 1, wherein said operating means includes time-delay means for delaying the deactivation of said processing apparatus in response to said second signals for intervals of time which elapse during transport of fibrous material from said first to said second portion of said path.

4. A combination as defined in claim 1, wherein said processing apparatus includes means for contacting the fibrous material in said second portion of said path with at least one treating medium.

5. A cOmbination as defined in claim 1, wherein said processing apparatus comprises means for blending at least one different type of fibrous material with the fibrous material of said charges.

6. A combination as defined in claim 1, wherein said detector means includes photosensitive transducer means.

7. A combination as defined in claim 1, wherein said conveyor means comprises a plurality of discrete conveyors.

8. A combination as defined in claim 1, further comprising means for arranging successive charges on said conveyor means in a discontinuous stream.

9. A combination as defined in claim 1, wherein said treating means comprises a plurality of processing apparatus each of which is activatable and deactivatable by said operating means.

10. A combination as defined in claim 1, wherein said processing apparatus includes means for adding to said fibrous material a plurality of treating media and said operating means comprises means for selecting said treating media.

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