GB1604270A - Apparatus for supplying tobacco - Google Patents

Description

(54) APPARATUS FOR SUPPLYING TOBACCO (71) We, HAUNI-WERKE KORBER & CO KG., a German Company of Kampchaussee 1222, 2050 Hamburg 80, Germany (Fed. Rep.), do hereby declare the invention, for which we pray that a Patent may be granted to us, and the method by which it is to be performed to be particularly described in and by the following statement: The present invention relates to apparatus for supplying tobacco to processing or consuming machines, particularly to cigarette making and like machines. More particularly, the invention relates to improvements in apparatus for continuously supplying tobacco to one or more processing machines.Still more particularly, the invention relates to improvements in tobacco supplying apparatus of the type wherein the processing machine receives tobacco which advances along an elongated path a portion of which is defined by a pneumatic conveyor wherein the particles of tobacco are advanced by a gaseous carrier medium.

An important requirement which must be satisfied by apparatus for delivery of tobacco to cigarette making and like machines is that the receptacle or hopper of the tobacco distributor should be filled to a predetermined level regardless of the rate at which the machine converts tobacco and wrapping material into plain cigarettes or analogous rod-shaped smokers' products. In other words, the rate of feed of tobacco particles to the distributor should fluctuate the same way as the rate at which the par ticles of tobacco are withdrawn from the distributor for conversion into a stream or directly into a rod-like filler.Periodic or intermittent delivery of batches of tobacco is likely to result in the accumulation of clumps of coherent particles which cannot be readily converted into a homogeneous sliver or carpet, i.e., into a moving body which constitutes the first stage of formation of a continuous tobacco stream.

East German Pat. No. 8 802 discloses a tobacco supplying apparatus wherein a pneu matic conveyor receives tobacco particles from a series of rotating drums having needles or pins which draw tobacco from a magazine. The speed of the drums is regulated in dependency on fluctuations of the supply of tobacco in the cigarette maker. Such apparatus is not entirely satisfactory because the drums subject tobacco shreds to a pronounced comminuting action, i.e., the percentage of short togacco and tobacco dust is very high. A similar apparatus is disclosed in British Patent No 661 015. Pneumatic conveyors which receive tobacco particles from a magazine containing rotating paddle wheels are disclosed in British Pat. No. 1 397 846.These prior art apparatuses share the drawbacks of the apparatus which is disclosed in the East German patent, i.e., the comminuting action of devices which feed tobacco into the pneumatic conveyors is excessive.

The invention is embodied in an apparatus for supplying tobacco to at least one tobacco processing machine, particularly to at least one cigarette making machine. The apparatus comprises pneumatic conveyor means having inlet and outlet means means for continuously feeding tobacco to the inlet means of the pneumatic conveyor means including at least one rotating feed screw which serves to deliver tobacco into the inlet means, and means for separating tobacco from the pneumatic carrier medium at the outlet means of the pneumatic conveyor means.

If the separated tobacco is to be delivered to the hopper of a distributor in a cigarette making machine, the apparatus further comprises a rotating air lock or an analogous device for transferring separating means to the hopper of the distributor.

The feeding means further comprises a to baccocontaining magazine having outlet means in communication with the inlet means of the pneumatic conveyor means. The feed screw is disposed in the interior (preferebly in the bottom portion) of the magazine and preferebly slopes upwardly, as considered in the direction of tobacco transport toward the outlet means of the magazine.

The bottom portion of the magazine may contain or constitute a substantially semicylindrical trough whose internal surface surrounds the lower half of the feed screw and is provided with longitudinally extending protuberances (e.g., ribs or teeth extending in substantial parallelism with the axis of the feed screw) which prevent circulation of tobacco in the trough as a result of rotation of the feed screw about its axis.

The magazine may contain two or more feed screws each of which delivers tobacco toward the inlet of a discrete pneumatic conveyor, and each discrete pnaumatic conveyor can deliver tobacco to a discrete processing machine.

The novel features which are considered as characteristic of the invention are set forth in particular in the appended claims. The improved apparatus 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.

Figure 1 is a schematic partly elevational and partly vertical sectional view of an apparatus which supplies tobacco to several cigarette making machines and is constructed and assembled in accordance with the invention; and Figure 2 is an enlarged transverse sectional view as seen in the direction of arrows from the line 11-Il of Figure 1.

The tobacco supplying apparatus which is shown in Figure 1 supplies tobacco to several magazines 1 which are disposed one behind the other and only one of which is actually shown.

Each magazine 1 serves to feed tobacco to the distributors of discrete cigarette making machines. The apparatus comprises a belt conveyor 3 which transports a wide layer of tobacco particles at right angles to the plane of Figure 1 and receives a continuous stream 2 of tobacco from an upwardly sloping carded belt conveyor 4. The conveyor 4 can receive tobacco from a dryer which is disposed downstream of one or more tobacco shredding machines, not shown. The conveyor which transports tobacco from the dryer to the conveyor 4 is not shown in the drawing; such conveyor may form part of a surge bin.

Each magazine 1 contains one or more feed screws 6. As shown in Figure 2, the illustrated magazine 1 contains two feed screws 6 which are adjacent and parallel to each other. Both feed screws are installed in the bottom portion of the magazine 1 and are partially surrounded by arcuate shrouds or troughs 9 defining two elongated channels in which the lower portions of the respective feed screws rotate. The shafts 6A of the feed screws 6 are mounted in bearings 7 and 8 which are installed at the exterior of the magazine 1. Each feed screw 6 slopes upwardly, as considered in the direction of transport of tobacco in the respective trough 9. The two trought 9 are identical; therefore, only the left-hand trough of Figure 2 is illustrated in full detail.The internal surface of each trough 9 has longitudinally extending protuberances in the form of saw teeth, ridges with rounded top portions or the like. The configuration of the protuberances 11 can be changed.

The magazine 1 comprises two downwardly extending outlet portions or ducts 12 wherein the particles of tobacco descend into the inlets of pneumatic conveyor pipes 13. The outlets of the pipes 13 discharge into discrete air sep arators 14 which have outlet openings 18 for the carrier medium (normally air) and screens 17 which intercept tobacco particles ahead of the openings 18, and cooperate with rotary air locks 19 which transfer tobacco particles into the distributors 16 of cigarette making machines. The purpose of the devices 14 is to segregate tobacco particles from the pneumatic carrier medium. One of the suction fans or other suitable suction generating devices which draw air from the ducts 12, through the respective pipes 13 and into the openings 18 is shown at 118.Each air lock 19 transfers tobacco particles onto a rotating drum 16A which cooper ates with a picker roller 16B. These parts are standard components of the respective distribu tors 16 and their construction forms no part of the invention.

Each distributor 16 comprises a level detec tor 21 which moniors the level of tobacco par ticles therein. Figure 1 shows one of these level dteectors 21, namely a photocell which trans mits signals to a variable-speed motor 22 for the respective feed screw 6. A discrete variable speed motor 22 is provided for each feed screw 6. The operative connection between the illus trated photocell 21 and the respective motor 22 is indicated by a phantom line 23. This connection includes means for reducing the speed of the motor 22 when the level of the supply of tobacco particles in the distributor 16 rises, and vice versa. The motor 22 (e.g., a reversible-polarity motor) receives a signal when the radiation issuing from the light source of the photocell 21 can reach the associated transducer.The speed of the motor 22 is then increased, e.g., to 120 percent of the capacity of the corresponding cigarette making machine. When the supply of tobacco particles in the distributor 16 rises to the level of the photocell 21, the speed of the motor 22 is recuced to that speed at which the corresponding feed screw 6 delivers tobacco particles at a rate corresponding to 80 percent of the requirements of the associated cigarette making machine.

The pneumatic conveyor systems including the pipes 13 are operated without interrupttions. The air locks 19 can be operates in synchronism with the corresponding cigarette making machines or the apparatus may be provided with discrete means for starting and arresting each air lock independently of the corresponding machine. The arrangement is preferably such that, when a machine is arrested, the corresponding air lock 19 continues to deliver metered quantities of tobacco for a certain interval of time.

The improved apparatus exhibits several important advantages. Thus, the speed of the feed screw or feed screws 6 can be readily regulated in such a way that the distributors 16 receive just as much tobacco as is necessary to establish highly satisfactory or optimum conditions for the formation of a uniform tobacco carpet or sliver which is thereupon converted into a continuous tobacco stream or directly into a rodlike tobacco filler. Moreover, tobacco is not lost on the way from the magazine or magazines 1 to the distributors 16 since the feed screws deliver only such quantities of tobacco which are accepted and advanced by the pneumatic conveyor pipes 13.This, in turn, brings about the advantage that there is no need for the provision of means which would recirculate tobacco from the outlets of the pneumatic conveyor pipes into the magazine or magazines 1, i.e., tobacco is not likely to undergo a pronounced comminuting action which would result in the formation of a high percentage of short tobacco and/or tobacco dust. The comminution of tobacco shreds is further unlikely on the ground that the threads of the feed screws 6 cannot repeatedly circulate tobacco in the interior of the magazine 1, i.e., the protuberances 11 in the troughs 9 insure that any tobacco which enters between the helices of the threads of the feed screws 6 invariably advances toward and into the respective outlet portions or ducts 12 and thence into the inlets of the corresponding pneumatic conveyor pipes 13.It has been found that the provision of two or more feed screws in a common magazine does not result in the formation of substantial quantities of short tobacco and/or tobacco dust. Such mounting of several feed screws in a common magazine is desirable because it contributes to compactness of the apparatus. The placing of feed screws into the bottom portion of the magazine 1 also contributes to compactness of the apparatus and further reduces the likelihood of excessive comminution of tobacco shreds which descend to the level of the feed screws. The quantity of tobacco which a feed screw expels from the magazine 1 per unit of time can be determined in advance with a high degree of accuracy if the feed screws slope upwardly as considered in the direction of transport of tobacco particles toward the respective ducts 12.

The troughs 9 further insure that the feed screws 6 receive preductable quantities of tobacco even if the magazine 1 is filled only to a certain level or if the magazine is nearly empty.

Each magazine 1 can be readily designed and dimensioned in such a way that it stores a sufficient supply of tobacco particles to satisfy the requirements of several processing machines.

This, combined with the provision of several discrete pneumatic conveyor tubes whose inlets receive tobacco from discrete outlet portions or ducts of the magazine 1, and each of which receives tobacco that is supplied by a discrete feed screw, contributes to compactness of the apparatus and to a reduction of the overall number of component parts.

The apparatus may be modified e.g. the operative connection 23 can be replaced with other means for regulating the speed of each feed screw in dependency on the quantity of tobacco in the hopper of the respective distdb- utor. Thus, each distributor can be equipped with level monitoring means which is connected with the respective motor 21 in such a way that the speed of the motor varies continuously, always as a function of changes of the level of the supply of tobacco in the hopper of the respective distributor.

WHAT WE CLAIM IS: 1. Apparatus for supplying tobacco to at least one tobacco processing machine, particularly a cigarette making machine comprising pneumatic conveyor means having inlet and outlet means; means for continuously feeding tobacco to said inlet means including at least one rotating feed screw arranged to deliver tobacco into said inlet means; and means for separating tobacco from the pneumatic carrier medium at said outlet means.

2. Apparatus as defined in Claim 1 for supplying tobacco to the distributor of at least one tobacco processing machine, further comprising means for transferring separated tobacco from said separator means to said distributor.

3. Apparatus as defined in Claim 1 or 2, wherein said feeding means further comprises a tobacco-containing magazine having outlet means in communication with the inlet means of said pneumatic conveyor means, said feed screw being disposed in said magazine.

4. Apparatus as defined in Claim 3, wherein said magazine comprises a bottom portion and said feed screw is located in said bottom portion.

5. Apparatus as defined in any one of Claims 1 to 4, wherein said feed screw slopes upwardly, as considered in the direction of tobacco feed toward said inlet means.

6. Apparatus as defined in any one of Claims 1 to 5, wherein said feeding means further comprises a trough having an internal surface adjacent to and partially surrounding said feed screw, said internal surface having protuberances extending in substantial parallelism with the axis of said feed screw.

7. Apparatus as defined in any one of Claims 1 to 6, said pneumatic conveyor means comprises a plurality of discrete conveyors each having an inlet and an outlet and said feeding means comprises a discrete feed screw for each pneumatic conveyor.

8. Apparatus as defined in Claim 7, wherein said feeding means further comprises a common tobacco containing magazine for said feed screws, said magazine having several outlets each communicating with the inlet of a discrete pneumatic conveyor and each feed screw being arranged to transport tobacco into a discrete outlet of said magazine.

9. Apparatus as defined in any one of Claims 1 to 8, further comprising a hopper arranged to receive separated tobacco from said air separating means, a variable-speed prime mover for said feed screw, and means for regulating the speed of said prime mover as a function of changes in the quantity of tobacco in

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (11)

**WARNING** start of CLMS field may overlap end of DESC **. sliver which is thereupon converted into a continuous tobacco stream or directly into a rodlike tobacco filler. Moreover, tobacco is not lost on the way from the magazine or magazines 1 to the distributors 16 since the feed screws deliver only such quantities of tobacco which are accepted and advanced by the pneumatic conveyor pipes 13. This, in turn, brings about the advantage that there is no need for the provision of means which would recirculate tobacco from the outlets of the pneumatic conveyor pipes into the magazine or magazines 1, i.e., tobacco is not likely to undergo a pronounced comminuting action which would result in the formation of a high percentage of short tobacco and/or tobacco dust.The comminution of tobacco shreds is further unlikely on the ground that the threads of the feed screws 6 cannot repeatedly circulate tobacco in the interior of the magazine 1, i.e., the protuberances 11 in the troughs 9 insure that any tobacco which enters between the helices of the threads of the feed screws 6 invariably advances toward and into the respective outlet portions or ducts 12 and thence into the inlets of the corresponding pneumatic conveyor pipes 13. It has been found that the provision of two or more feed screws in a common magazine does not result in the formation of substantial quantities of short tobacco and/or tobacco dust. Such mounting of several feed screws in a common magazine is desirable because it contributes to compactness of the apparatus.The placing of feed screws into the bottom portion of the magazine 1 also contributes to compactness of the apparatus and further reduces the likelihood of excessive comminution of tobacco shreds which descend to the level of the feed screws. The quantity of tobacco which a feed screw expels from the magazine 1 per unit of time can be determined in advance with a high degree of accuracy if the feed screws slope upwardly as considered in the direction of transport of tobacco particles toward the respective ducts 12. The troughs 9 further insure that the feed screws 6 receive preductable quantities of tobacco even if the magazine 1 is filled only to a certain level or if the magazine is nearly empty. Each magazine 1 can be readily designed and dimensioned in such a way that it stores a sufficient supply of tobacco particles to satisfy the requirements of several processing machines. This, combined with the provision of several discrete pneumatic conveyor tubes whose inlets receive tobacco from discrete outlet portions or ducts of the magazine 1, and each of which receives tobacco that is supplied by a discrete feed screw, contributes to compactness of the apparatus and to a reduction of the overall number of component parts. The apparatus may be modified e.g. the operative connection 23 can be replaced with other means for regulating the speed of each feed screw in dependency on the quantity of tobacco in the hopper of the respective distdb- utor. Thus, each distributor can be equipped with level monitoring means which is connected with the respective motor 21 in such a way that the speed of the motor varies continuously, always as a function of changes of the level of the supply of tobacco in the hopper of the respective distributor. WHAT WE CLAIM IS:

1. Apparatus for supplying tobacco to at least one tobacco processing machine, particularly a cigarette making machine comprising pneumatic conveyor means having inlet and outlet means; means for continuously feeding tobacco to said inlet means including at least one rotating feed screw arranged to deliver tobacco into said inlet means; and means for separating tobacco from the pneumatic carrier medium at said outlet means.

2. Apparatus as defined in Claim 1 for supplying tobacco to the distributor of at least one tobacco processing machine, further comprising means for transferring separated tobacco from said separator means to said distributor.

3. Apparatus as defined in Claim 1 or 2, wherein said feeding means further comprises a tobacco-containing magazine having outlet means in communication with the inlet means of said pneumatic conveyor means, said feed screw being disposed in said magazine.

4. Apparatus as defined in Claim 3, wherein said magazine comprises a bottom portion and said feed screw is located in said bottom portion.

5. Apparatus as defined in any one of Claims 1 to 4, wherein said feed screw slopes upwardly, as considered in the direction of tobacco feed toward said inlet means.

6. Apparatus as defined in any one of Claims 1 to 5, wherein said feeding means further comprises a trough having an internal surface adjacent to and partially surrounding said feed screw, said internal surface having protuberances extending in substantial parallelism with the axis of said feed screw.

7. Apparatus as defined in any one of Claims 1 to 6, said pneumatic conveyor means comprises a plurality of discrete conveyors each having an inlet and an outlet and said feeding means comprises a discrete feed screw for each pneumatic conveyor.

8. Apparatus as defined in Claim 7, wherein said feeding means further comprises a common tobacco containing magazine for said feed screws, said magazine having several outlets each communicating with the inlet of a discrete pneumatic conveyor and each feed screw being arranged to transport tobacco into a discrete outlet of said magazine.

9. Apparatus as defined in any one of Claims 1 to 8, further comprising a hopper arranged to receive separated tobacco from said air separating means, a variable-speed prime mover for said feed screw, and means for regulating the speed of said prime mover as a function of changes in the quantity of tobacco in

said hopper.

10. Apparatus as defined in Claim 9, wherein said regulating means includes a level detector for the supply of tobacco in said hop per.

11. Apparatus for supplying tobacco sub stantlally as hereinbefore described with reference to the accompanying drawings.