GB1137444A - Method and apparatus for forming a strand of tobacco - Google Patents

Abstract

1,137,444. Continuous rod cigarette making machines. B.A.T. CIGARETTENFABRIKEN G.m.b.H. 8 June, 1967 [24 June, 1966], No. 26525/67. Heading A2C. In an apparatus for forming a tobacco strand from tobacco which is continuously supplied in a loose condition and is fed into a continuously operating conveying arrangement comprising a channel closed on all sides, in a section extending from the feeding point into the said closed channels, parts at least of the tobacco are given an additional movement in the direction of conveyance until they come to a compacting point the position of which is adjustable and controls the said additional movement, whenceforth only forces producing conveyance at the normal strand speed act on the tobacco in the said channel. In one embodiment, Figs. 2, 3, tobacco is showered from a distributer V, on to a suction-backed conveyer belt 16, and between two perforated lateral conveyer belts 26, 28. A further conveyer belt 20, which is unperforated, and a conveyer belt 22 are both driven at substantially the speed at which the formed tobacco strand is to be conveyed, while the belts 16, 26, 28 are driven at approximately twice this speed. Belt 22 is vertically adjustable, and may be so adjusted as to continuously vary the channel 24 formed between the belts 20, 22, 26, 28. Suction is applied to the belts 26, 28 through a series of nozzles 37, each provided with a two way valve device 38, 39 the valves of which open in that region of the channel 24 where the tobacco is still being compacted, but close themselves automatically beyond the compacting point due to the greater resistance to air flow of the compacted tobacco strand. Provision may be made for altering the operative length of the belt 16. In another embodiment, Fig. 5, tobacco is showered on to a suction-backed perforated conveyer belt 50, the forward end of which receives its suction supply through cells 61 from a source 58 that feeds a hollow piston 59, only those cells 61 to the left (as shown) of the end 76 of the piston 59 being so supplied. A further perforated conveyer belt 65 receives suction through a series I to VIII, of chambers 67. Detection of the compacting point of the formed tobacco strand by control diaphragms 68 is used to automatically move the piston 59 so that its end 76 underlies this compacting point, position V in the example shown.