Patent GB-1138616-A (GB)
Title: Improvements relating to a method of and apparatus for processing tobacco
Inventor: MOLINS DESMOND WALTER
IPC: A24B7/12
Filed: 1965-03-26
Abstract: 1,138,616. Processing tobacco. MOLINS MACHINE CO. Ltd. 24 March, 1966 [25 March, 1965], No. 12979/65. Heading A2C. [Also in Division A4] A method of processing tobacco to produce a cigarette filler stream comprises the steps of cross-cutting unstemmed tobacco leaves into strips of a desired width along planes transverse to the midrib of each leaf, orientating the cut strips so that their midribs lie substantially parallel, cutting the orientated strips in planes parallel to the midribs to produce lamina shreds and stem portions of length substantially equal of the width of the strips, separating the stem portions from he lamina shreds and incorporating the lamina shreds in a cigarette filler stream. Tobacco leaves 2, on a conveyer 1, are cross-cut by knives 4 into strips 5. The strips are fed to a silo 6 comprising a conveyer 9, which oscillates in the direction of the arrow 12, and a conveyer 7. By feeding different types of grades of leaf a number of corresponding tobacco layers A1, B1, C1 and D1 are built up in the silo 6. When it is full the conveyer 7 feeds the tobacco mass towards a conveyer 14 provided with tines 17 which assist in removing a vertical slice 18 of tobacco. Slices 18 are fed in succession over a roller 21 to a further conveyer 22 and form a continuous stream of layers A2, B2, C2 and D2 thereon. The conveyer 22 delivers the slices to a further conveyer 25 in such a manner that the tobacco builds up in the form of a wedge comprising thin layers A3, B3, C3 and D3 of the different types of tobacco. The conveyer 25 moves the wedge of tobacco slowly to the right as viewed in the Figure and slices 31 are removed therefrom by an endless band 28 having tines 29. The slices 31 fall into a hopper 32 and are directed into a pneumatic conveying line 35 by a roller 33. The tobacco is discharged from a valve 37 into a hopper 39 one side of which comprises an endless band 40 which feeds the tobacco between rotating pairs of brushes which in turn feed them to a feed band 45. The strips are orientated so that their midribs lie in the plane transverse to that of the plane of the Figure. The strip orientating device 42-45 is as described in Specification 1,106,771. The orientated tobacco is directed between bands 47 and 48 to a mouthpiece 49 as described in Specification 1,089,363 and to a rotating drum 50 having knives disposed around its periphery, the cutting drum 50 being as described in Specification 1,089,362. A guide 51 leads the cut shreds to means 52 from which they are projected up a duct 54 to form a continuous filler stream on the underside of a perforated band 55 to which suction is applied. Tobacco trimmed from the filler stream is fed back into a shoot 406 which returns it to the projector means 52 at the end of the duct 54 in which the band 55 first enters (the band travelling into the plane of the Figure) so that the returned tobacco is drawn first up to the band 55 and not trimmed a second time. Particles of tobacco too heavy to be drawn up the duct 54 fall into a shoot 306 and thence into a passage 53 to which air is supplied. Any loose light particles which may have adhered to the heavy portions are returned to duct 54 via a passage 329. Heavy particles falling to the bottom of passage 53 are collected and reprocessed and may be introduced into apparatus 56 comprising a hopper, one side of which is a conveyer with tines for feeding the tobacco back to the entrance of the passage 329 from whence it is drawn into the duct 54. The apparatus 56 is also positioned so as to introduce the tobacco into the duct 54 at a point such that this tobacco will not be subsequently trimmed. The roller 301 of the projecting device 52 is divided into two parts, one part corresponding to the width of the drum 50 and the other to the width of the shoot 406. The latter part is driven at a speed less than that at which the former part is driven since the tobacco delivered from the cutting drum 50 is much looser than the trimmed tobacco delivered down the shoot 406.