Apparatus for building a tobacco stream

Abstract

A distributor for comminuted tobacco wherein a first conveyor, such as a carded drum, an endless apron or a pneumatic conveyor, supplies tobacco at a variable rate into the path of orbital movement of bristles on a rapidly rotating accelerating device. The bristles propel the particles of tobacco onto a narrow foraminous transporting belt which travels in a horizontal channel and accumulates a dense tobacco stream which is transported past a trimming device and into the wrapping mechanism of a cigarette rod making machine. The accelerating device is driven by a separate motor so that the peripheral speed of its bristles exceeds the speed of tobacco travel on the first conveyor. The stream is attracted to the transporting conveyor by suction, and the accelerating device is placed sufficiently close to the channel to insure that, during impact against the transporting conveyor or against the layer of tobacco thereon, the kinetic energy of all or nearly all tobacco particles is substantially identical. The accelerating device can be placed below, between or above the first conveyor and transporting conveyor and may form part of a winnowing assembly.

Description

BACKGROUND OF THE INVENTION

The present invention relates to improvements in apparatus for building a tobacco stream. More particularly, the invention relates to improvements in apparatus which can be utilized as distributors in machines for the making of a continuous wrapped tobacco filler rod which is ready to be subdivided into plain cigarettes, cigars or cigarillos of unit length or multiple unit length. One of the presently preferred uses of the improved stream building apparatus is as a distributor for a cigarette rod making machine.

As a rule, the distributor of a cigarette rod making machine comprises a magazine for a supply of tobacco shreds or for a mixture of tobacco shreds and ribs, and an apron which withdraws a relatively wide carpet of tobacco from the magazine and showers it into a channel having a bottom wall formed by the upper stretch of an endless conveyor belt which transports the growing tobacco stream toward the next processing station, such as a station accommodating a trimming or equalizing device which removes the surplus of tobacco and thereby converts the stream into a filler rod. The moving parts of the distributor are normally driven at a variable speed in synchronism with other components of the cigarette rod making machine so that the rate at which the distributor delivers a continuous tobacco stream corresponds to the rate at which the machine can process tobacco to form a continuous wrapped filler rod.

In many instances, the tobacco which forms a relatively wide carpet ofat a constant supply of tobacco shreds which insures a uniform rate of withdrawal of tobacco shreds by the carding carding 450 of the drum 441. The carding of the refuser 442 removes the surplus of tobacco shreds from the carding 450 and the remaining (equalized) layer of tobacco shreds travels below the mechanical retainer 443 to move into the range of the rapidly rotating picker roller 444. The picker roller 444 propels the shreds against the inner side of the baffle 433 along which the shreds descend by gravity to enter the funnel 434 and to thus move into the range of rapidly orbiting bristles 428 of the accelerating device 429 which is driven by the electric motor 432 at a speed exceeding the speed of the carding 450. The bristles 428 accelerate the shreds and propel them directly into the channel 403 or against the inner side of the second baffle 436 so that the shreds accumulating on the upper stretch of the transporting conveyor 404 form a relatively dense tobacco stream 402. As mentioned before, the density of this tobacco stream is perferably more than half the density of the filler in the wrapped rod which leaves the wrapping mechanism of the cigarette rod making machine embodying the distributor 401. The energy of tobacco shreds which are propelled by the bristles 428 greatly exceeds the energy of shreds which would descend by gravity from the funnel 434 directly into the channel 403. The suction chamber 406 holds the shreds of the stream 402 against slippage relative to the upper stretch of the transporting conveyor 404 which advances the stream toward the trimming device, not shown in FIG. 7. The acceleration of shreds which are propelled downwardly by the bristles 428 is sufficient to insure that the shreds forming the tobacco stream 402 not only deposit on top of each other but that the shreds also penetrate into the interstices between adjoining shreds which further contributes to greater density and uniformity of the stream 402. As explained in connection with FIG. 2, the density of the stream 402 is preferably sufficient to insure that this stream expands only slightly if the suction in the chamber 406 is terminated. In other words, when compared to the densifying and accelerating action of the bristles 428, the densifying action of air flowing into the chamber 406 is negligible.

An important advantage of the improved distributors is that they are capable of building a continuous tobacco stream wherein the particles of tobacco are densely packed so that the density of the entire stream at the upper side or at the underside (see FIG. 6) of the transporting conveyor is uniform all the way from the adjacent stretch of this conveyor and to the exposed surface of the stream. The electric motor or another prime mover which drives the accelerating device is preferably adjustable so that it can drive the bristles at a selected speed which is sufficient to build on the transporting conveyor a tobacco stream of desired density. Thus, the density of the tobacco stream is a function of the spped at which the bristles orbit about the axis of the accelerating device. Uniform density of the tobacco stream which is formed in the channel of the distributor is desirable because such stream can be readily equalized or trimmed to form a filler rod whose density is uniform in each and every zone thereof.

The distributors of FIGS. 2 and 7 (particularly the distributor of FIG. 7) exhibit the additional advantage that the magazine for the tobacco shreds can be placed very close to the channel 3 or 403. This insures that the consistency of shreds is changed very little during transfer onto the stream transporting conveyor. In addition, and as mentioned before, the carding 450 of the conveyor 441 shown in FIG. 7 is capable of withdrawing tobacco shreds at a uniform rate because the upper level of the mass of tobacco shreds in the magazine 435 fluctuates very little or not at all. The manner in which a detector 440 can control the motor or transmission for the conveyor belt 445 is well known in the art, and, therefore, the operative connection between the detector 440 and the belt 445 has not been shown in FIG. 7. It is clear, however, that the magazine 435 of FIG. 7 can also receive a mixture containing shreds and tobacco ribs and/or stem if the nature of the final product is such that its filler can contain both types of tobacco. The same holds true for the distributor 1, 101, 201 and/or 301.

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 my contribution to the art and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the claims.

Claims

1. In a machine for the making of tobacco filler rods, apparatus for building a tobacco stream comprising a source of comminuted tobacco; a tobacco feeding unit arranged to draw tobacco from said source and including a first conveyor operable at a plurality of speeds to transport the withdrawn tobacco along a first portion of a predetermined path; a tobacco stream transporting second conveyor adjacent to means defining a relatively narrow second portion of said path; an accelerating device comprising a rotary conveyor and wall means defining with said rotary conveyor a funnel which receives tobacco supplied by said first conveyor, said accelerating device being disposed between said first and second conveyors and operative to mechanically accelerate comminuted tobacco for transfer into and densification in said narrow second portion of said path wherein the accelerated tobacco forms a narrow growing stream which is transported by said second conveyor; and means for operating said accelerating device independently of at least one of said first and second conveyors.

2. Apparatus as defined in claim 1, wherein said first conveyor is located at a level above said accelerating device and the tobacco descends by gravity into the range of said accelerating device.

3. Apparatus as defined in claim 1, wherein said first conveyor is located at a level below said second conveyor.

4. Apparatus as defined in claim 1, wherein said second conveyor is located at a level above said accelerating device.

5. Apparatus as defined in claim 1, wherein said accelerating device is located at a level above said second conveyor.

6. Apparatus as defined in claim 1, further comprising means for classifying the particles of comminuted tobacco in advance of said accelerating device.

7. Apparatus as defined in claim 6, wherein said classifying means is located at a level above said accelerating device.

8. Apparatus as defined in claim 1, wherein said first conveyor is arranged to draw tobacco from said source and said feeding unit further comprises means for removing tobacco from said first conveyor, said accelerating device being disposed at a level above said second conveyor and below said removing means and said removing means being arranged to supply tobacco to said accelerating device by gravity flow.

9. Apparatus as defined in claim 8, wherein said first conveyor is a carded conveyor and said removing means comprises a picker roller.

10. Apparatus as defined in claim 9, wherein said feeding unit further comprises refuser means for equalizing the comminuted tobacco which is being drawn from said source by said carded conveyor.

11. Apparatus as defined in claim 1, further comprising an elongated tobacco channel provided with an elongated suction chamber, said second conveyor consisting of foraminous material and having an elongated stretch one side of which is adjacent to said chamber and the other side of which receives tobacco from said accelerating device.

12. Apparatus as defined in claim 1, wherein said second portion of said path is substantially normal to said first portion of said path, said first conveyor being arranged to supply a sliver of comminuted tobacco and said accelerating device comprising a rotary conveyor having an axial length at least approximating the width of the sliver on said first conveyor.

13. Apparatus as defined in claim 1, further comprising prime mover means for driving said first conveyor in synchronism with said second conveyor, said means for operating said accelerating device comprising a discrete motor.

14. Apparatus as defined in claim 13, wherein said first and second conveyors are endless belts.

15. Apparatus as defined in claim 1, wherein the filler rod produced by said machine has a predetermined density and said means for operating said accelerating device comprises means for driving said rotary conveyor at a peripheral speed which is high enough to impart to comminuted tobacco a kinetic energy sufficient to build on said second conveyor a tobacco stream whose density exceeds one-half of said predetermined density.

16. In a machine for the making of tobacco filler rods, apparatus for building a tobacco stream comprising a source of intermixed lighter and heavier tobacco particles, particularly intermixed tobacco shreds and ribs; a tobacco feeding unit arranged to draw tobacco particles from said source and including a first conveyor operable at a plurality of speeds to transport the withdrawn tobacco particles along a first portion of a predetermined path; channel means defining a relatively narrow second portion of said path; a second conveyor adjacent to said channel means and arranged to transport tobacco particles along said second portion of said path; means for transferring tobacco particles from said first conveyor and for transferring lighter particles onto said second conveyor, including an accelerating device comprising a rotary third conveyor and wall means defining with said third conveyor a funnel which receives tobacco particles supplied by said first conveyor, said accelerating device being disposed intermediate said first and second conveyors and being operative to mechanically accelerate said lighter and heavier particles whereby the flight spans of said heavier particles are different from the flight spans of said lighter particles with attendant segregation of said lighter particles from said heavier particles, said lighter particles being transferred into and densified in said channel means wherein said lighter particles form a narrow growing stream which is transported by said second conveyor; means for operating said third conveyor independently of at least one of said first and second conveyors; and means for intercepting said segregated heavier particles.

17. Apparatus defined in claim 16, wherein said transferring means further comprises means for removing lighter and heavier tobacco particles from said first conveyor. 18. Apparatus as defined in claim 17, wherein said lighter and heavier tobacco particles form on said first conveyor a relatively wide sliver and said first conveyor is a carded conveyor.

19. Apparatus as defined in claim 18, wherein said removing means comprises a picker roller.

20. Apparatus as defined in claim 16, wherein said third conveyor comprises a substantially cylindrical brush having an annulus of bristles.

21. Apparatus as defined in claim 16, wherein said operating means includes means for rotating said third conveyor at a peripheral speed exceeding each of said plurality of speeds.

22. Apparatus as defined in claim 16, further comprising a separator chamber for said funnel and said intercepting means.