Patent GB-941852-A (GB)
Title: Apparatus for producing a tobacco rod
IPC: A24C5/18
Filed: 1959-11-23
Abstract: 941,852. Cigarette-making machines. K. KÍRBER. Nov. 23, 1959 [Nov. 21, 1958; Dec. 2, 1958; June 12, 1959], No. 39634/59. Heading A2C. A movable feeder, which may be a wheel 3, Fig. 1, or belts 15, 151, Fig. 14, comprises a duct with a porous or perforated base through which suction is applied to take up a previously produced continuous tobacco stream. As shown in Fig. 1, the stream is picked up from a belt 4 and delivered to paper P passing into the rod-former of a continuousr o d cigarette-making machine, there being a suction transfer belt 24 of perforated steel. The wheel 3 has a peripheral conveying channel 6, Fig. 5, with a base formed as a gauze &c. screen 10 which may be soldered to the wheel body 7 and through which suction from an arcuate stationary chamber 13 in a cover 17 is applied via radial passages 11 and an annular duct 12. To assist tobacco delivery and channel cleaning compressed air is fed to the passages 11, Fig. 1, at 22, 14 respectively. There are flexible pipe connections 13<SP>1</SP> and 22<SP>1</SP>, 14<SP>1</SP> to suction and compressed conduits 19, 20 and a radial labyrinth packing between the members 7, 17. The suction chamber 13 need only extend around rather more than one quarter of the wheel periphery, and the suction may be reduced or eliminated adjacent a trimmer 23 in the form of a combing roll, rotary cutter or a brush which may be adjustable radially of the wheel and engage within the channel 6. Surplus tobacco removed by the trimmer 23 may be returned to supply. The channel width b, Fig. 5, can be adjusted using spacer rings 26, Fig. 7. The suction in the chamber 3 may be regulable as by a corpuscular radiation measuring device disposed downstream of the rod-former, or, to form cigarettes compacted at one or both ends, may be intermittently increased. Such cigarettes may also be formed by providing the channel 6 with spaced portions of increased width, or by pressing on the tobacco in the channel with an intermittently acting cam or plunger. The trimmer 23 may be dispensed with, the wheel 3 then engaging into the belt 4 as shown in Fig. 3. A corpuscular radiation measuring device in the chamber 13 may control tobacco delivery rate, the partitions 15 between the passages 11 being non-radial to give uniform ray absorption, or a radiation source penetrating the tobacco in the channel 6 axially may be used. In a modified feed wheel, Fig. 10 (not shown) the wheel engages into its supply belt and there are trimming means in the form of interengaging star wheels and a rotary knife located downstream of the wheel suction chamber. A second and stationary screen 36, Fig. 12, underlying the wheel radial passages has, over the extent of the suction chamber, (a) perforations 40<SP>1</SP> which decrease in number in the direction of wheel motion, (b) transverse slots which decrease in width, and may be increasingly spaced, in such direction or (c) a single circumferential slot which narrows in such direction. Thus the suction on the tobacco gradually diminishes, and opposite the trimming means the screen 36 has ports communicating with atmosphere so that the tobacco is completely uncompressed when trimmed. The wheel channel may have lateral suction openings. In Fig. 14, the perforated belt 15 communicates with suction chambers 45 having suction feed connections 46 of progressively smaller size in the direction of belt motion and each controlled by a needle valve like that 49. There is a trimmer 45a, 45b. Specifications 798,308, 941,853 and 941,854 are referred to.