GB2259845A

GB2259845A - Method and machine for producing continuous cigarette rods

Info

Publication number: GB2259845A
Application number: GB9219881A
Authority: GB
Inventors: Bruno Belvederi
Original assignee: GD SpA
Current assignee: GD SpA
Priority date: 1991-09-25
Filing date: 1992-09-21
Publication date: 1993-03-31
Anticipated expiration: 2012-09-21
Also published as: DE4231230A1; IT1253038B; ITBO910342A1; ITBO910342A0; GB9219881D0; GB2259845B

Abstract

A method and machine (1) for producing continuous cigarette rods (26), whereby a stream of tobacco (9) on the underside of a first suction type conveyor (8) is fed continuously to an unloading station (11) where the output end (12) of the first conveyor (8) is located over a paper strip (22) fed by a second conveyor (15) along a rod forming beam (24), and defines, with the second conveyor (15), a passage (21) engaged by the tobacco stream (9); the compactness of the rod (26) being controlled by varying the size of the passage (21) as a function of the physical characteristics, e.g. humidity, of the tobacco in the aforementioned stream (9). <IMAGE>

Description

1 - METHOD AND MACHINE FOR PRODUCING CONTINUOUS CIGARETTE RODS 1 The

present invention relates to a method of producing continuous cigarette rods.

In the cigarette industry, continuous cigarette rods are produced on machines with a shredded tobacco feed unit, wherein shredded tobacco is blown by an air current along a duct, the top end of which is closed by the bottom branch of a first suction type loop conveyor.

The tobacco issuing from the top end of the duct collects on the underside of the first conveyor so as to form, along the first conveyor, a continuous stream of tobacco which is fed continuously to an unloading station. Here, the output end of the first conveyor is located over the top portion of a second conveyor located a given distance from the first conveyor and defining, with the output end of the same, a passage engaged by the continuous stream of tobacco and by a continuous paper strip traveling on the second conveyor.

The second conveyor forms part of a rod forming unit, and provides for feeding the paper strip, together with the stream of shredded tobacco fed on to it at the unloading station, along a continuous cigarette rod forming beam, which is so designed as to gradually fold the paper strip transversely about the tobacco for forming a continuous cigarette rod, which is subsequently cut transversely into portions from which to form the cigarettes.

Known machines operating according to the above method present several drawbacks, mainly due to the fact that, for a substnntially given mass, the volume of the tobacco varies alongside variations in certain physical characteristics of the tobacco, such as humidity. That is to say, for a given mass, an increase in the humidity of the tobacco also results in an increase in volume; whereas, a reduction in humidity may result in reduced compactness of the cigarettes at the followup stages, thus resulting in end spill and possibly also in rejection of the cigarettes.

It is an object of the present invention to provide a method of producing continuous cigarette rods, designed to minimize the aforementioned drawback.

According to the present invention, there is provided a method of producing continuous cigarette rods, said method comprising a stage wherein a stream of tobacco on the underside of a first suction type conveyor is fed continuously to an unloading station at which the output end of the first conveyor is located over a paper strip fed by a second conveyor along a rod 4 - 3 forming beam, and forms, with the second conveyor, a passage engaged by the tobacco stream and by the paper strip; characterized by the fact that it comprises a further stage wherein the compactness of the rod is controlled by varying the size of the passage as a function of the physical characteristics, e.g. humidity, of the tobacco in said stream.

By varying the size of the passage, preferably within a flexible thickness range of the tobacco stream, it is therefore possible, prior to folding the paper strip transversely about the tobacco, to compensate for any variations in the volume of the tobacco stream caused by said physical parameters departing from predetermined mean values.

The present invention also for producing continuous cigarette According to the present provided a machine for producing rods, comprising a first suction continuous stream of tobacco; an the output end of forming beam; and forming beam and the forming beam, through said unloading station, and beneath the output end of the first conveyor; said first and second conveyor defining, at said unloading station, a passage engaged by the tobacco stream and the paper strip; characterized by the fact that actuating means relates to a machine rods.

invention, there is continuous cigarette type conveyor for a unloading station at the first conveyor; a continuous rod a second conveyor cooperating with the designed to feed a paper strip along - 4 are provided for varying the size of the passage as a function of the physical characteristics, e.g. humidity, of the tobacco in said stream.

The present invention will be described with reference to the accompanying drawing, which shows a schematic partial section, with parts removed for clarity, of a preferred non-limiting embodiment.

Number 1 in the accompanying drawing indicates a cigarette manufacturing machine comprising a shredded tobacco feed unit 2 in which shredded tobacco is blown by an air current along a substantially vertical duct 3, the top end of which is closed by the substantially horizontal bottom branch 4 of a permeable belt 5. Belt 5 is looped about a perforated chamber 6 communicating via conduit 7 with a known suction unit (not shown) defining, with chamber 6 and belt 5, a suction type conveyor 8.

The tobacco issuing from duct 3 collects on conveyor 8 to form, on the underside of branch 4 of belt 5, a continuous stream of tobacco 9, which, after being adjusted in thickness by a known shaving device 10, is fed continuously to an unloading station 11 where the of conveyor 8 is located over an intermediate portion of the substantially horizontal top branch 13 of a belt 14 forming part of a conveyor 15. Belt 14 is looped about two end pulleys 16 and 17 on either side of and respectively downstream and upstream from station 11 in the traveling direction 18 of branch output end 12 k 1.

13 through station 11, as well as about a drive pulley 19 with the edge of which belt 14 is maintained contacting by means of two guide pulleys 20. At station 11, branch 13 is located a given distance from conveyor 8, and defines, together with output end 12 of conveyor 8, a passage 21 engaged by tobacco stream 9 and by a continuous paper strip 22 traveling along conveyor 15.

Conveyor 15 forms part of a rod forming unit 23, and provides for feeding strip 22, together with tobacco stream 9 fed on to strip 22 at station 11, along a known forming beam 24 by which strip 22 is gradually folded transversely in known manner about tobacco stream 9. When folded fully about tobacco stream 9, the opposite longitudinal ends of strip 22 are joined in known manner by a known gumming device 25 to produce a continuous cigarette rod 26, which is subsequently cut transversely by a known cutting head (not shown) into portions (not shown) from which the cigarettes are formed.

In addition to conveyor 15, unit 23 also comprises a bed 27 supporting a frame 218 in turn supporting beam 24, conveyor 15 and a guide pulley 29 for strip 22 located upstream from pulley 17 in direction 18. Frame 28 is hinged to bed 27 by a pin 30 constituting the supporting shaft of pulley 16 and perpendicular to direction 18, and is swung about pin 30 by an actuator 31 located beneath station 11 and between frame 28 and bed 27, so as to vary the size of passage 21. More specifically, the distance between pin 30 and station 11 6 is such as to enable branch 13 to be moved by actuator 31, in relation to output end 12 and at station 11, in a direction substantially perpendicular to direction 18.

Actuator 31, in this case a pneumatic actuator, is operated by a known control system 32 controlled by a computer 33 as a function of the instantaneous values of given physical characteristics, e.g. humidity, of tobacco stream 9.

In actual use, by means of known sensors (not shown), computer 33 determines, instant by instant, the values of said physical characteristics of tobacco stream 9; compares these values with respective predetermined mean values; and operates actuator 31 for so varying the size of passage 21 as to flexibly and transversely compress or expand tobacco stream 9, for compensating for any change in the volume of stream 9 caused by a departure from said mean values, and so maintain the compactness of rod 26 substantially constant.

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Claims

1) A method of producing continuous cigarette rods (26), said method comprising a stage wherein a stream of tobacco (9) on the underside of a first suction type conveyor (8) is fed continuously to an unloading station (11) at which the output end (12) of the first conveyor (8) is located over a paper strip (22) fed by a second conveyor (15) along a rod forming beam (24), and forms, with the second conveyor (15), a passage (21) engaged by the tobacco stream (9) and by the paper strip (22); characterized by the fact that it comprises a further stage wherein the compactness of the rod (26) is controlled by varying the size of the passage (21) as a function of the physical characteristics, e.g. humidity, of the tobacco in said stream (9).

2) A method as claimed in Claim 1, characterized by the fact that the size of said passage (411) is varied within a flexible thickness range of said tobacco stream (9).

3) A method as claimed in Claim 1 or 2, characterized by the fact that the size of said passage (21) is varied by moving the second conveyor (15) in relation to the first conveyor (8) and in a direction substantially perpendicular to the traveling direction (18) of the second conveyor (15) at said unloading station (11).

4) A method as claimed in any one of the foregoing Claims, characterized by the fact that the size of said passage (21) is varied by rotating said forming beam (24) in relation to the first conveyor (8) and about an axis (30) perpendicular to the traveling direction (18) of the second conveyor (15) at said unloading station (11).

5) A machine (1) for producing continuous cigarette rods (26), comprising a first suction type conveyor (8) for a continuous stream of tobacco (9); an unloading station (11) at the output end (12) of the first conveyor (8); a continuous rod forming beam (24); and a second conveyor (15) cooperating with the forming beam (24) and designed to feed a paper strip (22) along the forming beam (24), through said unloading station (11), and beneath the output end (12) of the first conveyor (8); said first and second conveyor (8, 15) defining, at said unloading station (11), a passage (21) engaged by the tobacco stream (9) and the paper strip (22); characterized by the fact that actuating means (31) are provided for varying the size of the passage (21) as a function of the physical characteristics, e.g. humidity, of the tobacco in said stream (9).

6) A machine as claimed in Claim 5, characterized by the fact that it also comprises a movable frame (28) supporting the forming beam (24) and the second conveyor (15); and a bed (27); said actuating means (31) being located between said bed (27) and said frame (28).

4 i - 9 7) A machine as claimed in Claim 6, characterized by the fact that said movable frame (28) is hinged to said bed (27) so as to rotate, in relation to said bed (27) and said first conveyor (8) and by virtue of said actuating means (31), about an axis (30) perpendicular to the traveling direction (18) of the second conveyor (15) at said unloading station (11).

8) A method of producing continuous cigarette rods, substantially as described and illustrated herein with reference to the accompanying drawing.

9) A machine for producing continuous cigarette rods, substantially as described and illustrated herein with reference to the accompanying drawing.