US3590826A - Machine for blending tobacco or the like - Google Patents

Abstract

Two or more types of tobacco are fed by separate conveyor lines into a blending unit wherein such types are mixed. One of the conveyor lines contains a measuring and control unit which measures the rate of tobacco feed and controls the rate of operation of each other conveyor line so that the ratio of tobacco types reaching the blending unit remains within a desired range. The measuring unit can also control the operating rate of one conveyor line.

Description

United States Patent Waldemar Wochnovvskl Hamburg-Volksdori; Helmut Bsumnnn, Hamburg-Bergedorl,

[72] Inventors both of. Germany [21 Appl. No. 635,597

I22] Filed May 2, 1967 [45] Patented July 6, 1971 73] Assignce llauni-Werke Korber 8: Co. KG.

Hamburg-Bergedori, Germany I32] Priority May 4, 1966 [33] Germany I54] MACHINE FOR BLENDING TOBACCO OR THE 2,656,142 10/1953 Wcckerly 177/70 2,827,058 3/1958 Bogarty 131/108 3,098,572 7/1963 Ouestcr H 131/21 X 3,204,71 l 9/1965 Boadlc et a1. 177/70 3,209,845 10/1965 Hollander... 177/70 3,232,296 2/1966 Dreher 131/22 (A) 3,242,321 3/1966 Chopc... 131/21 X 3,113,576 12/1963 Bell 131/21 (1)) 3,146,780 9/1964 Harrison,.1r. ct 31.. 131/21 (13) 3,428,052 2/1969 Patterson 131/21 (B) X FOREIGN PATENTS 495,614 4/1930 Germany 131/149 673,308 3/1939 Germany.. 131/149 1,022,141 l/l958 Germany... 131/149 1,103,209 3/1961 Germany 131/149 730,527 5/1955 Great Britain 131/136 82,123 10/1956 Netherlands 131/149 826,914 l/1938 France 131/109 83,123 10/1956 Netherlands Primary Examiner-Joseph S. Reich Attorney-Michael S. Striker ABSTRACT: Two or more types of tobacco are fed by separate conveyor lines into a blending unit wherein such types are mixed. One of the conveyor lines contains a measuring and control unit which measures the rate of tobacco feed and controis the rate of operation of each other conveyor line so that the ratio of tobacco types reaching the blending unit remains within a desired range. The measuring unit can also control the operating rate of one conveyor line.

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PATENTED JUL 6 Ian 590 a M SHEET 5 0F 6 18 1 9 ms 9/ E d 135s 1360 F I2 1351 135a 11s4 IN VE NTOPS PATENTEU JUL 6 l9?! SHEU 8 OF 6 I! J I I IN VENTORS MACHINE FOR BLENDING TOBACCO OR THE LIKE CROSS-REFERENCE TO RELATED APPLICATION Certain devices and circuits which can be utilized in the blending machine of the present invention are disclosed in US. Pat; No. 3,4l9,Ul granted Dec. 3i, l968 to Waldemar Wochnowski and assigned to the same assignce.

BACKGROUND OF THE INVENTION The present invention relates to blending of fibrous matern als, 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 chcwer ettpccts 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 oflcaf may be too strong or too weak. Manu' facturers of tobacco products have developed recipes for blending different tobacco types in such a way that a blend nonnally contains leaf from 2 or more yeals' crops and that such blend contains a mixture of Oriental with Burlcy, Vir' ginia, 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, treatment of Oriental tobaccos following moistening of bales is very simple and consumes little time. On the other hand, preliminary treatmom of Burley (prior to blending) is much more extensive and consumes more time.

Accordingly, it is an important object of our invention 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 very little or not at all.

Another object of the invention is to provide a machine which can blend tobacco: and maintains a desired 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.

A concomitant 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 su bjccted prior to blending.

SUMMARY OF THE INVENTION One feature ofthe present in ention resides in the provision of a machine for blending various types of tobacco or like fibrous materials. The machine comprises blending means which may include one or more rotary drums installed upstream of one or more processing apparatus wherein the blend undergoes further treatment, at least two conveyor lines for supplying to the blending means different types of material (for example, shredded tobacco and comminuted tobacco ribs.) measuring means which may include a weighing conveyor installed in one ofthe conveyor lines to measure the rate of material flow to the blending means, and proportioning means provided in other conveyor line for regulating the rate of material flow as a function of the results of measurements carried out by the measuring means.

The proportioning means may include a feeder belt which can be driven at several speeds, and a regulator or speed changer assembly which receives signals from the measuring means to change the speed of the feeder belt in response to changes in the rate of material feed in the one 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 THE DRAWING FIG. I is a flow sheet illustrating in diagrammatic form certain elements of a machine which may be utilized for.auto matic blending oftwo tobacco types;

FIG. 2 is a similar flow sheet illustrating certain elements of a machine which is intended for blending of three tobacco yp FIG. 3 is a flow sheet illustrating a blending machine which constitutes a modification ofthe machine shown in FIG. 2;

FIG. 4 is a flow sheet illustrating a blending machine which constitutes a modification of the machine shown in FIG. 2 or FIG. 5 is a fragmentary top plan view ofa blending machine which is similar to the machine represented by the flow sheet of FIG. I;

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

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

FIG. 8 is a fragmentary schematic side elcvational 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. I0 is a diagrammatic schematic view of a first modifi' cation of the blending machine shown in FIG. 9;

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

FIG. I2 is a diagrammatic schematic view of a third modification of the blending machine shown in FIG. 9;

FIG. I3 is a top plan view of a timelag unit which can be utilized in the blending machines of FIGS. I to 4; and

FIG. I4 is a vertical section substantially as seen in the direction of arrows from the line XIV-XIV of FIG. I3.

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. I is a flow sheet illustrating in diagrammatic form a machine for blending two tobacco types, grades, classes or qualities. The numerals 200] and 2002 denote two conveyor lines each of which advances one of the two tobacco types. The lines 200] and 2002 deliver tobacco to a blending means or blending unit 2004 (c.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 200] 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 to 2009 may include moistening, casing-applying, cooling, drying, cutting, heating, dcstalking, mixing, bulking and other devices. A proportioning or metering unit l0 is in stalled in the conveyor line 200l downstream of the processing apparatus 2006, 2007, i.c., this proportioning unit 20l0 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 2(ll0 comprises an automatic fccdcr 201 l which has storage capaci ty, a weighing or measuring conveyor 20I2 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 20". The weighing conveyor 2012 supplies to the regulator 2013 impulses which indicate the actual rate of tobacco flow and the regulator 20l3 changes the delivery of the feeder 201 I when such actual rate deviates from a predetermined or desired rate. The feeder 20 is capable of storing a variable quantity of tobacco and insures that the rate at which the weighing conveyor 20l2 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 20l4 which is located downstream of the processing apparatus 2008, 2009. The weighing conveyor 2014 supplies to the regulator 20l3 impulses which indicate the aforementioned predetermined or desired rate of tobacco flow through the weighing conveyor 20 [2 in the conveyor line 2001. The conveyor, lines 200i, 2002 further accommodate two delay or timelag 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 2004 is the same as the time required by successive increments of the second tobacco type to cover the distance between the weighing conveyor 20" 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 20]] and weighing conveyor 20l4 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 timclag unit which can be used in the blending machine of FIG. I is shown in FIGS. 13 and [4.

The rate at which the feeder 200i supplies tobacco to the weighing conveyor 20l2 depends on the rate of tobacco advance through the weighing conveyor 2014. ln 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 200]. The weighing conveyor 2014 controls the proportioning unit 20l0 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 20]] can store tobacco to compen sate for eventual interruptions in delivery from the processing apparatus 2006. The conveyor 20 is a rated value setting means for the proportioning upit 20I0.

FIG. 2 is a flow sheet illus'trating in diagrammatic form a machine for blending three tobacco types, for example, Burley, Oriental and Virginia tobacco. This machine comprises three conveyor lines 2020, 202i and 2022 which deliver the respective tobacco types to a blending unit 2024 installed in a common conveyor line 2023. The numerals 2025 to 203! 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, 202] and 2022. Two proportioning or metering units 2032 and 2033 are installed in the lines 2020 and 2022, each thereof is analogous to the proportioning unit 20l0 of FIG. I. 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 ofthc 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. I. The nature of processing apparatus 2029, 2030 in the conveyor line 202I 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 202l and it will be seen that the weighing conveyor 2034 is located at the receiving end of this line 2021. For example, the line 202! 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 timelag 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 US. Pat. No. 3,419,0l5 of Wochnowski. The recordings are reproduced with a requisite delay and the resulting signals are transmitted to the regulators 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 202i, 2022 respectively accommodate adjustable delay or timelag units 2041, 2042 which are analogous to the delay units 20l5, 20l6 of HG. I. The delay units 204I-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 at which the conveyor line 202] 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 tobacco type.

The flow sheet of HO. 3 illustrates in diagrammatic form a third blending machine which comprises three conveyor lines 2050, 205] and 2052 serving to feed three tobacco types to a common co'nvcyor 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 205], 2052 and 2050. The construction of each of these proportioning units is the same as that of the proportioning unit 20l0 in the machine of FIG. I. The processing apparatus 2062 is installed in the conveyor line 205! 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 tip paratus 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 of the proportioning unit 2063 is connected with the three regulators 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 timelag units 2068 and 2069.

The proportioning unit 2063 insures that the processing ap paratus 2062 invariably receives a desired amount of tobacco per unit oftimc. lts weighing conveyor 2067 controls the regulators of the proportioning units 2064, 204 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, 207], 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 with the conveyor lines 2070-2072. The lines 2070-2072 respectively accommodate adjustable first proportioning or metering 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 l0 in FIG. I. 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 timclag units 2090, 209I which are located downstream of the proportioning units 2085, 2087 and perform the same functions as the units 20I5, 20I6 of FIG. I. The first three proportioning units 2082-2084 insure that the desired ratio between the three tobacco types is established, to a considerably 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 the 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. I. The first conveyor line 3 includes endless belts I, IA. IB and 32, and the second conveyor line 4 comprises endless belts 2, 2A 3| 3IA, 3IB. 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 4| having a weighing conveyor 43 and an automatic fcedcr 42.

The belts l and 2 are respectively driven by variable-speed electric motors S and 6. A regulator or speed changer for the motor 6 includes a bridge circuit 7 wherein the taps I0, I I 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 I0, I I are displaced synchronously with the movement of belts I and 2. The distances covered by these sliders are proportional to but shorter than the distances covered by the upper stringers of the belts I and 2. The speed reducing transmissions for the sliders I0, II are shown at In, lb and each thereof receives motion from a roller or sprocket of the respective belt. The potentiometer 8 is connected in se' ries with a delay or timelag unit l2 which can be adjusted manually by an adjuster I3. Two other branches of the bridge circuit 7 respectively comprise symmetrically arranged fixed resistors I4, IS. The connection to a current source includes terminals I6, I7. The sliding contact or slider I9 ofa variable resistor I8 in the diagonal or zero branch of the bridge circuit 7 is connected with the motor 6 for the belt 2, the r.p.m. of the motor 6 varies as a function of voltage changes, i.e., as a function of changes in the setting of the slider I9. 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 5 for the belt I. This relation is offset in time due to the provision of delay or timelag unit 12 and is adjustable by changing the position of the slider I9.

The belts I and 2 respectively deliver tobacco to belts IA and 2A, and the belts lA, 2A respectively deliver tobacco to belts I8, 31. The directions in which the belts of FIG. 5 advance the respective tobacco types are indicated by arrows. The belts IA, IE, 32, 2A, 3l, 3 l A, 318 and 34 are driven by a common prime mover 35, c.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 3"! 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 IB 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, 366 the first of which receives stemmed tobacco from the belt 18 downstream of the inlet to the last cutting machine 37. The belt 360 returns such tobacco onto the belt lI-l upstream ofthe first cutting machine 37. The belts 3611-360 are driven by the motor 35. The belt 36!: is adjacent to a level-sensing devicc 38 which includes 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 I.

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 motor 35. The weighing conveyor 40 is a functional equivalent ofthe weighing conveyor 20I4 in FIG. I and is located upstream of the point where the belt 313 discharges the second tobacco type onto the belt 32. 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 belt I, 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 bclts 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 I and motor 5 constitute means for admitting to the recirculating conveyor or feeder 36 tobacco leaflaminae at a rate which is a function of the quantity of material on the belts 360-361, the determination of the supply of laminae on the belts 36a-36c being carried 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 I 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 4| which is a functional equivalent of the proportioning unit 2010 in FIG. I 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 4t 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 variablespeed motor 46. The quantity of tobacco on the feeder 42 is detected by a level-sensing device 47 which is preferably ldtTlllCal 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 50 denotes a ralcd-value-setling device which is adjustable by an adjuster 51. The ratcd-valuc-setting device 50 is connected with an averaging circuit 52 for the variablc-specd drive motor 46 of the feeder 42 and includes a scale provided with, for example, l gradualions each corresponding to a different sequence of rates of tobacco flow. Each selling of the adjuster eorresponds to a different range of tobacco feed rates by the feeder 42, and only one rated value is selected at a time. The regulator 44 further comprises a timer 55 which is arranged to permit passage of signals from the storing units 49, 50 at predetermined intervals, for example, at 50-seeond intervals. If the minimum level indicator of the level-sensing device 47 causes the storing unit 49 to send a signal via timer SS and on to the ratcd-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 fill-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-valuc-selting device 50 a signal which is generated by the maximum level indicator of the lcvel-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 -50-sccond intervals. Depending on the momentary selling of the adjuster St, the rated-value-sctting 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, 4)v The arrangement is such that a first setting of the adjuster 5| causes the ratcd-valuc-setting device 50 to furnish if) different tobacco feed rates which change automatically in response to signals from the storing unit 48 or 49. If the adjuster St is reset, the device 50 will furnish to different tobacco feed rates. The programming of IO feed rates for each setting of the adjuster St 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, and vice versa. The exact construction of the timer 55, rated-value-sctting 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 35in 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 minumum 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. it is assumed that the belt I 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 constilutc the travelling bottom walls of boxes or bins which contain substantial supplies of the respective tobacco types. The hells l, 2 withdraw tobacco from the respective bins at a conslant 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 I and is conveyed by the belts IA, 18 toward the inlets of the cutting machines 37 in the processing apparatus 30 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 minumum level indicator of the level-sensing device 38. Shredded tobacco issuing from the cutting machines 37 travels with the belt 32 an is weighed by the conveyor 40 prior to reaching the blending unit 33.

The surplus of stemmed tobacco which cannot citler the cutting machines 37 continues to travel with the upper stringer of the belt IB and is transferred onto the first belt 360 of the recirculating conveyor 36. If the surplus of stemmed tobacco is substantial, the maximum level indicator of the levelsensing device 38 sends a signal to the speed changer 39 and the latter reduces the speed of the motor 5 for the belt I. 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 IA. 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 timelag unit II 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 I to the point where shredded tobacco mixes with the ribs coming from the belt 3| l3. Due to the provision of cutting machines 37, tobacco which is fed by the belt I requires more time to reach the point where its shredded particles mix with tobacco ribs.

Ribs which are fed by the conveyor belt JIA can pass 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.

If the proportioning unil 4| 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 4! 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 40 in the conveyor line 3 and by the proportioning unit 4| in the conveyor line 4. Rapidly occuring fluctuations in the rate at which the belts l 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 l and 2 and/or in the bins which furnish tobacco to these beltsv Furthermore, fluctuations in the rate at which the belts l and 2 supply tobacco types can also develop due to peculiari ties 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. so that, at the very worst, the ratio of shredded tobacco to ribsjn the blending unit 33 will change very slowly. The magnitude of fluctuations of the ratio of tobacco shreds to ribs can be siblected in advance by appropriate adjustment -of the rated-value-setting device 50 through the intermediary of the adjuster Sl.

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 4| in the conveyor line 4 in the same way as described for the weighing conveyor 2lll4 and regulator or speed changer 2013 of FIG. I. In other words, the weighing conveyor 40 measures the quantity of tobacco shreds and causes the proportioning unit 4] 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 timelag unit l2 of the bridge circuit 7 causes the motor 6 to drive the belt 2 with a certain delay following starting of the motor 5 for the belt I. Furthermore, the delay unit 12 causes the motor 6 to change its speed with a delay following any changes in the speed ofthe motor 5.

The machine of FIG. 5 is clearly analogous to the machine represented by the flow sheet of FIG. I with the t 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. I. The weighing conveyor of FIG. I corresponds to the conveyor 40 of FIG. 5, and the proportioning unit 2010 of FIG. I corresponds to the unit 41 of FIG. 5. The feeder 20I I, weighing conveyor 2012 and regulator or speed changer 2013 of FIG. I 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 of FIG. I.

Of course, the timclag or delay unit I2 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 SIB is less than the time required by tobacco discharged from the belt I 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 aforedcscribed mode of operation of the motor 6, namely, that changes in its speed take place with a certain delay following changes in the speed of the motor 5 constitutcs 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 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 ml, 102 of the two conveyor lines 103, I04 and the motors I05, I06 respectively correspond to the parts I, 2, 3, 4 and S, 6 of FIG. 5. The bridge circuit I07 constitutes a speed changer for the motor I06 ofthe belt I02 but does not control the starting and stoppage of this motor. The speed-reducing transmissions for the sliders IIO, III are shown at [01a, [01b and the elements I08III, II4, IIS, "8, I19 of the bridge circuit I07 are functional equivalents of similarly numbered elements in the bridge circuit 7 of FIG. 5. The delay or timelag unit I2 of FIG. 5 is replaced by a delay or timelag unit I60 which is connected between the transmis sion [01a and the motor I06. The delay unit I60 may be ad justed by a manually operable adjuster l6], and this delay unit serves to start the motor 106 with a delay which has been selected in advance by the adjuster I6l. The rotational speed of the motor I06 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 I05. If the motor I05 is arrested, the motor I06 continues to run at a preselected basic spe'iid. The means for arresting the motor I06 includes a detector or scanner I62 which is mounted adjacent to the belt I02 or I02A and opens the circuit of the motor I06 by conventional means, such as a relay I63, when it detects that the respective belt is free of ribs. The detector I62 is preferably located in the path of ribs which are being showered from the discharge end of the belt I02 onto the upper stringer ofthc belt I02A.

FIG. 7 illustrates a digital speed changer circuit 67 for regulating the ratio at which the bolts 61, 62 of two conveyor lines feed two tobacco types, for example, stemmed tobacco and tobacco ribs. The belts 6], 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 6], 62 are respectively provided with equidistant reflectors 70, 7| which are scanned by photoelectric detectors 72, 73. The detector 72 com prises a light source 74 which directs a beam of light against successive reflectors 70 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 oflight against successive reflectors 7I 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 h and the output c 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 0 and b is translated into a positive or negative signal which is transmitted by the output c and con trols the signal amplifier 80. The output of the detector 72 is further connected with an adjustable counter circuit 8t 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 BI 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 8|. 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 I; a series of signals which influence the speed of the motor 66 so that the ratio of speeds of the belts 6i, 62 remains within a predetermined range. Fluctuations in the speed of the belt 6I 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 ofsignals received at the inputs 0 and 1). Furthermore, the counter circuit 81 insures 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 20I0 of FIG. I, to the unit 2032 of FIG. 2, or to the unit 4I 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 2" for the motor 250. The

belt 202 serves to convey 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 2I0. The conveyors 2 I0, 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-scnsing device ZOI which includes a minimum level indicator 23], a maximum level in dicator 232 and two signal-storing units or bins 237. 238.

The signal amplifier assembly 2 for the motor 250 in cludes a preamplifier 248 and a second amplifier 249, described below. The weighing conveyor 2l0 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-valuwselting device 208, and sends signals to the preamplifier 248 of the signal amplifier assembly 2I Iv The rated-value-setting device 208 comprises a potentiometer 240 whose slider 24] is connected with thejunction 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 2l0 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 I2 of HG. I. the potentiometer 240 could be adjusted by the weighing conveyor 20l4.

The minimum level indicator 23l ofthe level'sensing device 20] 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 I; 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 0 of the storing units 237, 238 cause theseunits to transmit signals to the circuit averagingjunction 239, and signals received at the inputs h 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 throughout of tobacco (quantity per unit oftimc).

The minimum level indicator 23] 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. Ifthc 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 ratcdwaluesetting 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 reccption 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 inter rupts 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 b of the storing unit 238 whereby the latter ceases to send signals to the junction 239. i.c.. this junction can receive a signal from the storing unit 237 or 238 but never from both storing units at the same time.

When a signal coming from the receiver 236 of the max imum 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 transmined by the storing unit 237 so that the speed ofthe motor 250 is then changed accordingly.

Signals transmitted by the storing units 237. 238 are on posed by signals produced by the signal generator 209. This signal generator comprises a potentiometer 243 having it slider 242 which is connected to the junction 239. The weighing conveyor 2l0 comprises a vertically movable platform 2l3 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 2I0.

The second amplifier 249 of the signal amplifier assembly 2| l comprises control coils 249a, 249!) which convey currents whose strength is a function of signals transmitted by the stor ing units 237, 238. Consequently, the working coils 249e, 249d 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 minumum level indicator 23| 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 vary long or very short intervals to 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 I001 for Virginia tobacco and a second conveyor line l07I 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 I00! for Virginia tobacco comprises three sections 1002, I003, I004. The median section I003 comprises an endless receiving bclt I084 which is a takeoff belt and serves to ad vance the tobacco from the processing apparatus in the section I003 to apparatus in the section 1004. This median section I003 comprises three portions 10030, I003b, 1003c which respectively include endless belts I088, I089 and I09I. The belt I091 serves to feed tobacco into a processing apparatus I006 which is used to mix tobacco with casing or flavoring solution. A similar apparatus is disclosed in the aforementioned US. Pat. No. 3.4 l 9,0 l 5, to Wochnowski. The output of the processing apparatus I006 (hereinafter called mixer for short) descends onto the aforementioned discharging belt I084 and is advanced toward one or more further processing apparatus in the section I004. The drum I006d of the mixer I006 is rotatable about an axis which is slightly lined with reference to a horizontal plane and is driven by a variablcspced motor 1007. This motor 1007 also drives the belt I09l. The mixing zone in the interior of the drum l006d receives casing from the atomizer nozzle of a conduit [006a which is connected with a tank l006b and contains a variable-delivery pump I006c. The arrow I008 indicates the direction in which the casing fiows when the pump I006c is in operation. The conduit [006a further contains an adjustable metering valve I009 which is regulated by a speed changer or regulator I0ll for the motor I007. The speed changer l0ll is further connected with a moisture detector I012 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 I007. The moisture detector I012 determines the moisture content oftohacco which has been mixed with casing and, thercfoi'e. the measurement carried out by detector 1012 is indicative of the intensity or thoroughness of mixing action which takes place in the drum l006d. The moisture detector I012 comprises capacitor means 1012a forming part of an oscillator circuit (not shownl whose frequency may be changed periodically by a nonillustrated 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 100611 of the mixer 1006 is associated with a detector or sensor 1013 which determines the throughput of tobacco and is connected with a signal generator I014. The detector ll3 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 I013 produces a signal indicating that the delivery of tobacco by the belt 1091 is let minatcd, and a second output 1017 which sends signals in the absence ot'a signal from the detector 1013v The signal generator 1014 may comprise a light-sensitive electrtmic receiver. The outputs 1016, 1017 are respectively connected with two amplifiers 1018, 1019 whose outputs are connected with a two-way switching device 1021. The switching device 1021 has a single output which is connected with the speed changer or regulator 1011. A third input ofthe 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 simul' taneously 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-sctting device 1022 with the speed changer I011 when the signal generator I014 sends signals through the amplifier 1019 (i.c., when the belt 1091 delivers tobacco to the drum 100611). 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 efl'ects closing of the valve 1009.

The operation ol'thc mixer 1006 is as follows:

When the detector I013 determines that the belt 1091 does not supply tobacco into the drum 1006d, the signal generator I014 sends a signal via amplifier 1018 and such signal causes the switching device 1021 to connect the speed changer 101 l 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 ofa fresh charge of Virginia tobacco to the belt 1091, the rated-value-sctting device 1022 is set by the adjuster 1023 to insure that each increment of tobacco will be mixed with a predetermined amount of easing. When the freshly admitted charge (coming from the belt 1089 in the portion 10031; of the conveyor line section 1003) reaches the belt 1091, the detector I013 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 onto the conveyor 1091 from the conveyor 1089. The switching device 1021 then connects the rated-valuc-setting device 1022 with the speed changer I01] and the latter Opens the valve 1009 and starts the motor 1007 for the drum l006d. The arresting switch 1024 is then disconnected from the speed changer The throughput of the valve 1009 and the speed of the motor 1007 will depend on the setting of the rated-valuesetting device 1022, and the motor 1007 continues to drive the belt 1091 and the drum 1006d until the detector 1013 sends a signal in dicating that the charge of tobacco has been consumed. The arresting switch 1024 then stops the motor 1007 and effects closing ofthe valve 1009 in a manner as described above.

The portions 1003b and 1003!: of the conveyor line section 1003 accommodate other processing apparatus. For example. and as shown in FlCl 9, the portion 1003b accommodates a stripping or destalking machine 10250 which is associated with a pneumatic separator 1025. A similar combination is disclosed, for example, in US. Pat. No. 3,205,209 granted to Wochnowslti et al. on Aug. 9, 1966. 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 1025!) whose blades destalk tobacco leaves in cooperation with a fixed basket and which is driven by a variable-speed motor 1025/. 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 takeoff belt 1025c and the laminae descend onto the aforementioned belt 1089. The separator I025 comprises a closed pneumatic circuit which contains a suction fan 1025d driven by a motor 1025:. The hopper of the stripping machine 1025a receives moistened tobacco leaves from a conveyor belt 1083. The motors 1025c, 1025] can be started and arrested by a system of switches mounted on a control panel I02Sg. This control panel receives signals from a detector or sensor 162 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 control panel 10253 to start the motors 1025:, I025]. The detector 262 also sends signals which disconnect the motors 1025c, 1025ffrom the source ofelectrical energy.

The component parts of the moistcning apparatus 1026 in the portion 1003a of the conveyor line section 1003 are analogous to the pans 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 scctions 1072, 1073, 1074. The first section 1072 merely contains a belt 1096 (or a series of bells) serving to deliver Oriental tobacco from a source to a belt 1097 in the section 1073. The belt I097 supplies tobacco into the drum 1076d of a moistening apparatus 1076 which is similar to the moistening apparatus 1026 and mixer 1006. The drum [076d 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 ap paratus 1076 further includes a moisture detector 1082 which is adjacent to a discharging belt (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 to the mixing zone of the drum 1076d. The junction 1081 is further connected with the slider of a potentiometer I092 forming part of a rated-valuesetting 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, 1025-10250, 1026 and 1076 are started and arrested in automatic response to signals received from detectors I013, 262, 1033, i.e., as a function of the tobacco feed. Of course, the travel of Virginia tobacco through processing apparatus 1006, 1025-10254, 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 ap paratus 1076 for Oriental tobacco. The speed changer I087 starts the motor 1077 when the detector I013 senses the presence of Virginia tobacco on the belt 1091. Thus, the rate at which the discharging bclt 1089 delivers Oriental tobacco from the section 1073 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 ofthe 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. to 7. The belts I, 2 of FIG. 5 would correspond to the belts 1084 and 1098 oI'FlG. 9.

Of course, a tobacco stream or mat will require a certain amount 01' 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 :cction I003 of FIG. 9 and the entry of such leaves into the as sociatcd moistening apparatus 1026. Such rime 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 ofthe drum I026d. A :uitable delay or timelag 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 circuit of the moistening apparatus 1026. The delay unit 1020 can be installed between the amplifier I018 and the two-way switching device 1021 and is indicated by broken line: 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 circuit! of the processing apparatus 1025-10250, and 1076 can be provided with analogous delay or timelag units.

If the delay unit 1020 of FIG. 9 delays only the stoppage of the motor 100), the mixer 1006 will be in operation but will receive no tobacco during the interval required by tobacco lhrcd: to advance from the detector 1013 to the mixing zone in the drum I006d. Such short-lasting "dry" run of the mixer I006 does no harm.

In the blending machine of FIG. 9. the rated-value-sctting device 1022 in the circuit of the mixer 1006 can be lot by the adjulter I023. The setting lelected by the manually operated adjuner 1023 will be effective when the tobacco :hredt enter the portion 1003: of the conveyor line section 1003. The setting of the device 1022 for a fresh charge of tobacco can be changed lublequent to transport of the preceding charge beyond the drum I006d. If it i: desired to process charges of different eon:l:tencie: in rapid sequence. the time allotted for manual operation of variou: adjulters (1023, 1043) will be rather :hort.

FIG. 10 lllultratel diagrammatically a blending machine wherein the proceuing lpparatu: can be properly reset or adjulted for proceuing of one or more freuh charger of tobacco while the preceding charge it :till in the procers of undergoing treatment on it: way to the blending location. The setting for treatment of next-following charge: doe: not affect the treatment ofthe running charge. In the diagram of FIG. 10. all such part: which are clearly analogous to or identical to the parts dclcribed in connection with FIG. 9 are denoted by :imiltir reference numeral: railed by 100. Thu, the mixer 1106 of FIG. 10 correlpond: to the mixer 1006 of FIG. 9. The blending machine which I: :hown lcltematically in FIG. 10 further comprile: a locking unit 1157 which i: installed between the two-way :witchlng device 1121 and the rated value setting device 1122. The output of the locking unit 1157 I: connected with the amplifier 1119. and this locking unit 1157 comprises 1 timer I158 adapted to be set by a manually operated adjuater I159. The locking device 1157 also comprire: storing device 1161 for signals received from the rated-value-setting device 1122. The timer 1158 is connected between the ampli- Her 1119 and the storing device 1161, and the latter is connected between the rated-value-sctting 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 I 158 for the shortest possible intcrval which is required to complete the treatment of a known charge in the mixer 1106. When the signal generator I114 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 machine 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 1114 via output connection 1117 and amplifier I119 restarts the mixer I106. The two-way switching device 1121 then receives signals from the signal-storing device 1161 independently of the rated-value-setting device I 122 and sends signali to the speed changer or regulator 1111 for the motor 1107. The storing device 1161 blocks the passage of signals from the rated-value4etting device 1122 if such signals are different from those transmitted by the storing device 1161. The latter will cease to transmit signals upon elapse ol' the interval selected by the adjuster 1159 for the timer 1158 and upon reception from detector 1113 of: signal that a fresh charge of tobacco is being led to the mixer I106. The operation of the speed changer 1111 i: then controlled by signals from the rated-vaIue-ttetting device 1122 which can transmit the same signals as before or difl'erent signals, depending upon whether or not the adjuster 1123 was reset during the interval when the mood changer [III was receiving signals from the storing device 1161.

The timer 1158 is reset to zero when the speed changer II 11 receives :ignalti from the rated value letting device 1122 and begins to count I: new interval which can be the same as the previously counted interval or it different interval, depending on the :hortettt anticipated time required for processing of the charge which it! being fed into the drum of the mixer I106. The setting of the timer 1158 i: carried out by the adjuster 1159.

It will be men that the rated value: of signal: which will control the :peed changer 1111 during treatment of the next-fob lowing charge can be lelected before a charge ha: completed its advance through the mixer 1106 and while the charge which travels through the mixer I: treated in accordance with a recipe which might but need not be the :umc u the recipe for the next-following charge. In other word:. the locking unit 1157 :crve: to program the blending machine for a future ope ration while the machine it in actual me. It i: also poasible to select in advance two or more future operation: of the machine it the manually adjunable timer 1158 is replaced with a programmable timer. Alto, the machine of FIG. 10 may be equipped with a counter I063 (:hown by broken lines) which can automatically :top the motor 1107 after elapse ot' a predetermined period of time :elected by a :ultable adjuster I064. The counter 1063 it connected directly to the :peed changer IIII and its :lgnal override: the :ignal: coming from the locking unit 1157. The counter 1063i: :etin motion in lI-I- tomatic relponle to :tarting oi the motor and Interrupts its count if the operation at the mixer 1106 i: interrupted. Signals to :tart, interrupt and rutart the counter 1063 are t'urnilhed by the :pced changer 1111.

FIG. 11 illuitrnte: schematically l blending machine which comprise: delay or tlmellg device: :crvlng to compensate for different time: 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 adjoin ing processing apparatus. The numerals I20JA, I288, I283 denote three endless belts forming part ofti conveyor line for a given tobacco type. A processing apparatus I226 is adjacent to the median belt I288 and this appai'attis is arranged to perform the same function as the moistening apparatus I026 in the left-hand part of FIG. 9. A detector I233 is adjacent to the belt I288 upstream of the drum of the moistening apparatus I226 which latter is driven by a variable-speed electric motor I227. Two amplifiers I238, I239 receive signals through out put lines I236, I237 ofa signal generator I234 which is connected with the detector I233. The motor I227 is regulated by a speed changer l23l which however, does not regulate the metering valve I229. The latter is regulated by a separate regulator I23IA. The speed changer l23l is connected with a gate I250 which is Connected with a rated-value-selting device I242. The regulator I23IA is connected with a rated value-setting device I242. The regulator I23IA is connected with a delay or timelag unit I25l, and a gate I252. The rated value setting device I23 for the regulator I23IA can be set by a manually operated adjuster I254. The rated value setting device I242 for the speed changer l23l can he set by an at; juster I234. The numeral I244 denotes an arresting switch which can be connected with the speed changer l23| to arrest the motor I227. The switch I244 can be connected in circuit with the motor 1227 through a gate I255, a delay or timelag unit I256 and a control switch I257.

The valve I229 can he closed through the intermediary ofa delay or timelag unit 1258 and a gate I259 by an arresting switch I260 which is analogous to the arresting switch I244. A timer I26l whose input is connected with the motor I227 has three outputs connected with the delay or timelag units I25I, I256 and I258.

The operation is as follows:

The adjusters I243, I254 will be manipulated to set the rated-value-setting devices I242 and I253 in order to select rated valves for the speed changer I23l and regulator I23IA. The signals coming from devices I242, I253 can reach the speed changer I23] and regulator I23IA only when the respective gates I250, I252 are open. The regulator [231A will receive signals with a delay determined by the delay or timelag unit I251.

The zero or shutoff signals coming from the arresting switches I244, I260 will reach the speed changer I23I and regulator I23IA only when the respective gates I255, I259 are open. Such signals will be delayed by the delay units I256 and I258.

The delay unit l25| is set for a delay or interval r which is required by an increment of tobacco to advance from the de tector 1233 to the inlet ofthe moistening apparatus I226. The delay unit I258 is set for an interval 1, which is required by tobacco to cover the distance from the detector I233 to the moistening zone in the apparatus I226, 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 I256 is set for a delay or interval 1, required by tobacco to travel from the detector I233 to the discharge end of the belt I288. The intervals 1,, r, and t are functions of the speed of the motor I227; therefore, the timer I26! is connected with the motor I227 and receives therefrom signals whose frequency is a function of the speed of the belt I228 and the speed of the drum in the moistening apparatus I226. The timer I26! controls the delay units I251, I256, I258 in such a way that the intervals 1,, r,, r. are functions of the frequency at which the timer receives impulses from the motor I227.

The gates I252, I259, I250 and I255 are controlled by amplifiers I238, I239 in such a way that the gates I255. I259 open only when the signal generator I234 sends a signal through the output line I236 and amplifier I23tl, and that the gates I250. I252 open only when the signal comes from IIIL output line I237 and amplifier I239, i.e., when the detector I233 detects the advance oftohacco on the belt I288.

When the belt I288 does not deliver tobacco, the detector I233 causes the signal generator I234 to send a signal through the output line I236 and amplifier I238 so that the gates I255 and I259 are open. The valve I229 is closed by the arresting switch I260 and a control switch I262. The speed changer I23I stops the motor I227 in response to a signal from the arresting switch I224 and control switch I257.

lfthe belt 1203A thereupon admits tobacco to the belt I288 (which is idle), the detector I233 sends a signal which causes the gates I255, I259 to close and the gates I250, I52 to open. The control switches I257, I262 are disconnected from the respective arresting switches I244, I260 but this does hot affect the position of the valve I229 which remains closed. The rated-value-setting device I242 is connected with the speed changer I23! because the gate I250 is open whereby the speed changer I23I starts the motor 1227 without delay at a speed determined by the ratcd-value setting device I242. The speed changer I231 turns off the control switch I257. The timer I261 receives from the speed changer I23] impulses at a frequency which is a function of the speed of the motor I227. The belt IZllIl is driven by the motor I227 and begins to deliver tobacco from the discharge end of the belt I203A toward the moistening apparatus I226 while the valve I229 continues to prevent admission of water or steam. Upon elapse of the interval r, signals from the rated-value-setting device I253 can reach the regulator 1231A through the gate I252 which is open. The regulator I23IA turns off the control switch I262 and opens the valve I229 to the extent determined by the rated-value-setting device 1253. The valve I229 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 I229 to the nozzle or nozzles in the drum of the processing apparatus I226, tobacco reaches the nozzles tie, the interval r has elapsed) and the circuitry of FIG. II then remains in the just described state until the detector I233 sends a signal which indicated the absence of tobacco on the belt 1288. Such signal closes the gates I250, I252 and opens the gates I255, I259. The speed changer I23I and regulator I23IA are disconnected from the rated-value setting device I242, I253 but they continue to control the speed of the motor I227 and the position of the valve I229 because they have stored the last signals from the devices I242, I253. The motor 1227 continues to run and the valve I229 remains open. The motor I227 is stopped when the signal coming from the arresting switch I244 and passing through open gate I255 reaches the control switch I257 with a delay determined by the delay unit I256. The valve I229 is closed when the signal coming from the arresting switch I260 through the gate I259 (which is open) reaches the control switch I262. The delay unit I258 permits the signal coming from the arresting switch I260 to reach the control switch I262 with a delay t,, i.e., when the last increment of the charge has covered the distance from the detector I233 to the spray nozzles in the drum of the moistening apparatus I226. The control switch I262 erases in the regulator I23IA the last signal from the rated-value-setting device [251' When the interval 1 has elapsed, the entire charge has been conveyed beyond the belt I288 and the delay unit I256 per mits the signal from the arresting switch I244 to reach the control switch I257 which arrests the motor I227 and erases in the speed changer I231 the last signal from the rated-valuesetting device I242. The timer I261 ceases to receive impulses from the motor I227 so that the circuitry is deenergized. The procedure is repeated in the abovedescribed sequence when the detector I233 detects the first increment of a fresh charge coming from the belt I203A. The motor 1227 will be driven at a speed selected by the rated-valuc-setting device I242 and the valve I229 will open to the extent depending on the intensity of signals transmitted by the rated-value-setting device I253. The device I242, I253 may but need not be reset by adjusters I243, I254, depending on the type of charge and on the desired moistcning of tobacco in the processing apparatus I226.

In the machines represented by the diagrams of FIGS. and 11, the rated-value-setting devices 1022, 1042, 1242, 1253 can be adjusted after the respective regulators 1011, 1031 1231, 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 indicated the end of the transport of tobacco In many instances, the recipe (ie., 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 ofthe respective rated value setting devices after completion or during processing of each successive charge. FIG. 12 illustrates scbc matically a portion of a blending machine wherein a series o1 adjustments of the HIILd VtJIUC-SCIIIHQ means can be scanned in a predetermined sequence so that two or more charges can be processed in accordance with a predetermined program even though the recipes for the charges are different. The parts shown in FIG 12 are analogous to those described iii connection with FIG 9 and are denoted by similar reference numerals with 3110 added to each numeral. The structure ot FIG. 12 diffeis from that of II(r. I mainly in that the rated value-setting device 1022 (and the ad uster 1023) is replaced with a more sophisticated circuit including a four-pole step by-step switching device 1350 having a central contact con nected with one input of a two way switching device 1321 The four poles of the switching device 1350 are connected with four rated-value-setting devices 1351, 1352, 1353, 1354 Each of the devices 1351-1354 can be set by one of four adjusters1355,1356,13S7,1358,and each ofthese devices cor responds 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. 10 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 lltc 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 fol lowing ratcd-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 inactivatcd (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 ofopera' tion 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 a four ratcdwaluesetting 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 con ncction with operation of the processing apparatus 1006 in FIG. 9. A moisture detector is shown at 1112 in l lti 10, .it 1208 in FIG. 11 and at 312 in FIG. 12, respectively and in each instance the function of the moisture detector and its cooperation with the valves 1109, 1229 and 1309 respective ly, is the same as that pertaining to the moisture detector 1012 and the valve I009 appearing in the upper hand portion of FIG.

In the blending machines which embody the structures shown in FIGS. 912, differences in time required for treatment of tobacco types in various rocessing apparatus tttc compensated for in response to signals received from strategi cally distributed detectors or sensors. Another possibility ol compensating for such differences has been mentioned in F105. 1- 4 which respectively show delay or timelag units 201S2016, 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 units of FIGS. 13 and 14 comprises an elongated box or bin 401 having a superstructure 402 of rectangular outline and including sidewalls of the bin. The superstructure 402 preferably consists of wood. The bottom wall of the bin 40] 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 DC motor 406 which is connected with a source 408 of polyphase alternating current through the intermediary of a rectifier 407. The output voltage of the 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 fcetls tobacco to a takeoff belt 419.

In operation, the supply conveyor 4111 delivers tobacco into the bin 401 and onto the upper iitringer of the belt 403. This belt advances tobacco toward the withdrawing device 422 wh ch feeds tobac co onto the takeoff belt 419. The speed of the belt 403 can be varied infinitely by the adjuster 409, Le, the belt 403 constitutes with parts 406409 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 incrcmcnLs 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.

As shown in FIG. 2, the conveyor line 2020 does not contain it 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 we claim as new and desired to be protected by Letters Patent is set forth in the appended 1. A machine for blending various types of tobacco or like fibrous materials, comprising blending means; at least two conveyor lines for supplying to said blending means different ty es of material; measuring means provided in one of said conveyor lines for determining the rate of material flow per unit of time therein and means provided in the other conveyor line for regulating the rate of material flow as a function of the results of measurements carried out by said measuring means.

2. A machine as defined in claim 1, further comprising second material flow rate regulating means provided in said one conveyor line and including said measuring means.

3. A machine as defined in claim 1, wherein said conveyor lines are arranged to supply the respective types of material to said blending means at a constant ratio, said proportioning means comprising feeder means having a variable supply of the respective material type for delivery to said blending means and means for delivering to said feeder means material at a rate which is a function of the quantity of material in said supply.

4. A machine as defined in claim I, wherein each of said conveyor lines comprises a conveyor for the respective material type, variable-speed drive means for each of said conveyors, and regulator means for regulating one of said drive means as a function ofthe speed of the other, 'iie means.

5. A machine as defined in claim 4, further comprising at least one processing apparatus provided in said one conveyor line intermediate sad ring means and the respective conveyor for subjecting the respective material type to at least one treatment for affecting the rate of delivery of material per unit of time toward said measuring means, the conveyor in said one conveyor line being arranged to supply to said processing apparatus material at a rate which at least temporarily exceeds the capacity of said processing apparatus whereby the processing apparatus refuses the surplus of the thus delivered material, recirculating means for collecting upstream of said processing apparatus such surplus material which is refused by said processing apparatus, nd speed changer means for regulating the drive means of the conveyor in said one conveyor line a s a function of the amounts of refused material on said recirculating meansv 6. A machine for blending various types of tobacco or like fibrous materials, comprising blending means; at least two conveyor lines for supplying to said blending means different types of material a measuring device provided in one of said conveyor lines for determining the rate of material flow per unit of time; a proportioning device provided in the other conveyor line for regulating the rate of material flow as a function of the results of measurements carried out by said measuring device; and timelag means provided in at least one ofsaid con veyor lines between said blending means and the respective device for regulating the time required by successive increments of the respective material to cover the distance between the respective device and said blending means.

7. A machine as defined in claim 6 further comprising at least one additional conveyor line for supplying to said blend ing means a further type of material, one of said conveyor lines being arranged to deliver one type of said material at a speed which is less than the speed of material in the remaining conveyor lines, one of said timelag means being provided in each of said remaining conveyor lines.

8. A machine for blending various types of tobacco or like fibrous materials, comprising blending means; at least two conveyor lines for supplying to said blending means different types of material, at least one adjustable processing apparatus provided in at least one of said 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 said conveyor lines; and operating means for adjusting said processing apparatus in response to signals from said detector means, said detector means and said processing apparatus being provided in different conveyor lines.

9. A machine for blending various types to tobacco or like fibrous materials, comprising blending means; at least two conveyor lines for supplying to said blending means different types of material; at least one first adjustable processing apparatus provided in at least one of said conveyor lines and operative to treat the respective material type; signal-generating detector means for detecting changes in he rate of supply of material by one of said conveyor lines; first operating means for adjusting said processing apparatus in response to signals from said detector means; at least one second adjustable processing apparatus provided in the other conveyor line and operative to treat the respective material type; and second operating means for adjusting said second processing apparatus in response to signals received from said detector means, at least one of said processing apparatus being arranged to add to a respective material type one or more treating media and the respective operating means comprising rated-value-setting means for selecting said treating media, said rated-value-setting means having a plurality of settings in each of which said ratedwalue-settlng means selects a different treating medium and said rated-value-setting means being adjustable to select at least one new treating medium while said one processing apparatus treats a charge of material with a previously sclectd tf eating medium.

If]. A machine for blending various types of tobacco or like fibrous materials, comprising blending means; at least two conveyor lines for supplying to said blending means different types of material; at least one first adjustable processing apparatus provided in at least one of said conveyor lines and operative to treat the respective material type; signal-generating detector means for detecting changes in the rate ofsupply of material by one of said conveyor lines; first operating means for adjusting said processing apparatus in response to signals from said detector means; at least one second adjustable processing apparatus provided in the other conveyor line and operative to treat the respective material type; second operating means for adjusting said second processing apparatus in response to signals from said detector means, at least one of said processing apparatus being arranged to add to a respective material type one or more treating media ad the rcspcu tive operating means comprising rate-valuesetting means for selecting said treating media; and locking means associated with said rated-valuc-setting means to prevent changes in the addition of treating media during treatment of a charge of the respective material type and to effect repeated addition of the same treating medium upon completion of the treatment of-a charge.

If. A machine for blending various type of tobacco or like fibrous materials, comprising blending means; at least two conveyor lines for supplying to said blending means different types of material at a constant ratio; first proportioning means provided in one of said conveyor lines for regulating the rate of material flow toward said blending means, said proportioning means comprising feeder means having a variable supply of the respective material type for delivery to said blending means, and means for delivering to said feeder means material at a rate which is a function of the quantity of material in said supply; second proportioning means provided in the other conveyor line for regulating the rate of material flow toward said blending means, said second proportioning means comprising fceder means arranged to accumulate a variable supply of he respective material type and means for evacuating from said last-mentioned feeder means material at a rate which is a function of the quantity of material in said last-named supply, each of said proportioning means further comprising levelscnsing means comprising maximum and minimum level indicators arranged to produce signals indicative of the quantity of material in the respective supply, said second proportioning means further comprising intermediate means interposed between the respective indicators and the means for evacuating material from the respective feeder means, said intermediate means comprising means for efl'ecting the evacuation of more material when the respective maximum level indicator detects that the respective supply is replenished to a maximum value and to effect evacuation of less material when the respective minimum level indicator detects that the respective supply is depleted to a minimum value, said intermediate means further comprising rated-value-setting means responsive to signals produced by the respective indicators and communicating with means for effecting a stepwise reduction in the rate of evacuation of material from the respective supply in response to signals from the respective minimum level indicator and for effecting a stepwise increase in the rate of evacuation of material in response to signals from the respec tive maximum level indicator.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 ,590,826 Dated July 6 1971 InVentor(S) Waldemar Wochnowski et a1 It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

On the cover sheet, "[32] Priority May 4, 1966 Germany [3 1] H 59300" shouId read [32] Priority May 4 1966 May 13 1966 May 17 1966 33] Germany [3 H 59300; R 59390; H 59 426 Signed and sealed this 12th day of September 1972.

(SEAL) Attest:

ROBERT GOTTSCHALK EDWARD M.FLETCHER ,JR.

Commissioner of Patents Attesting Officer uscoMM-oc wave-Poo 9 U 5 GOVERNMENT PRINTING OFFICE DID 0-366-35

Claims (10)

1. A machine for blending various types of tobacco or like fibrous materials, comprising blending means; at least two conveyor lines for supplying to said blending means different types of material; measuring means provided in one of said conveyor lines for determining the rate of material flow per unit of time therein and means provided in the other conveyor line for regulating the rate of material flow as a function of the results of measurements carried out by said measuring means.

2. A machine as defined in claim 1, further comprising second material flow rate regulating means provided in said one conveyor line and including said measuring means.

3. A machine as defined in claim 1, wherein said conveyor lines are arranged to supply the respective types of material to said blending means at a constant ratio, said proportioning means comprising feeder means having a variable supply of the respective material type for delivery to said blending means and means for delivering to said feeder means material at a rate which is a function of the quantity of material in said supply.

4. A machine as defined in claiM 1, wherein each of said conveyor lines comprises a conveyor for the respective material type, variable-speed drive means for each of said conveyors, and regulator means for regulating one of said drive means as a function of the speed of the other drive means.

5. A machine as defined in claim 4, further comprising at least one processing apparatus provided in said one conveyor line intermediate sad ring means and the respective conveyor for subjecting the respective material type to at least one treatment for affecting the rate of delivery of material per unit of time toward said measuring means, the conveyor in said one conveyor line being arranged to supply to said processing apparatus material at a rate which at least temporarily exceeds the capacity of said processing apparatus whereby the processing apparatus refuses the surplus of the thus delivered material, recirculating means for collecting upstream of said processing apparatus such surplus material which is refused by said processing apparatus, nd speed changer means for regulating the drive means of the conveyor in said one conveyor line a s a function of the amounts of refused material on said recirculating means.

6. A machine for blending various types of tobacco or like fibrous materials, comprising blending means; at least two conveyor lines for supplying to said blending means different types of material a measuring device provided in one of said conveyor lines for determining the rate of material flow per unit of time; a proportioning device provided in the other conveyor line for regulating the rate of material flow as a function of the results of measurements carried out by said measuring device; and timelag means provided in at least one of said conveyor lines between said blending means and the respective device for regulating the time required by successive increments of the respective material to cover the distance between the respective device and said blending means.

7. A machine as defined in claim 6 further comprising at least one additional conveyor line for supplying to said blending means a further type of material, one of said conveyor lines being arranged to deliver one type of said material at a speed which is less than the speed of material in the remaining conveyor lines, one of said timelag means being provided in each of said remaining conveyor lines.

8. A machine for blending various types of tobacco or like fibrous materials, comprising blending means; at least two conveyor lines for supplying to said blending means different types of material, at least one adjustable processing apparatus provided in at least one of said 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 said conveyor lines; and operating means for adjusting said processing apparatus in response to signals from said detector means, said detector means and said processing apparatus being provided in different conveyor lines.

9. A machine for blending various types to tobacco or like fibrous materials, comprising blending means; at least two conveyor lines for supplying to said blending means different types of material; at least one first adjustable processing apparatus provided in at least one of said conveyor lines and operative to treat the respective material type; signal-generating detector means for detecting changes in he rate of supply of material by one of said conveyor lines; first operating means for adjusting said processing apparatus in response to signals from said detector means; at least one second adjustable processing apparatus provided in the other conveyor line and operative to treat the respective material type; and second operating means for adjusting said second processing apparatus in response to signals received from said detector means, at least one of said processing apparatus being arranged to add to a respective material type one or more treating media and the rEspective operating means comprising rated-value-setting means for selecting said treating media, said rated-value-setting means having a plurality of settings in each of which said rated-value-setting means selects a different treating medium and said rated-value-setting means being adjustable to select at least one new treating medium while said one processing apparatus treats a charge of material with a previously selected treating medium.

10. A machine for blending various types of tobacco or like fibrous materials, comprising blending means; at least two conveyor lines for supplying to said blending means different types of material; at least one first adjustable processing apparatus provided in at least one of said 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 said conveyor lines; first operating means for adjusting said processing apparatus in response to signals from said detector means; at least one second adjustable processing apparatus provided in the other conveyor line and operative to treat the respective material type; second operating means for adjusting said second processing apparatus in response to signals from said detector means, at least one of said processing apparatus being arranged to add to a respective material type one or more treating media ad the respective operating means comprising rate-value-setting means for selecting said treating media; and locking means associated with said rated-value-setting means to prevent changes in the addition of treating media during treatment of a charge of the respective material type and to effect repeated addition of the same treating medium upon completion of the treatment of a charge.

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