method for detecting and reducing variations in the uniform distribution of the particles of tobacco into a continuous stream of tobacco and apparatus for carrying out this process

摘要

929,338. Cigarette-making machines. D. W. MOLINS, G. F. W. POWELL, F. POCOCK, A. M. LABBE, and MOLINS MACHINE CO. Ltd. Sept.. 15, 1959 [Sept. 15, 1958], No. 29511/58. Class 130. [Also in Groups XXIX and XXXV] Variations in the uniformity of a tobacco filler formed on a continuous rod machine are detected by passing air through the filler to detect variations in its air-permeability along its length. In Fig. 2 the filler, formed by suction on the underside of a perforated conveyer 1, is passed through a suction chamber 70, variations in pressure in which, caused by variations in the airpermeability of the filler, are detected by a capsule device 75 which adjusts a trimming device 27 towards or away from the filler to trim more or less tobacco therefrom and correct for the variations in the filler. The trimming device comprises a pair of rotating discs 27, Fig. 6, which, with the co-operation of a brush 28, trim tobacco off the lower surface of the filler, recesses 29 being provided to leave denser portions at regular intervals for the production of dense end cigarettes. The discs 27 are carried by an adjustable lever 42 connected at its right-hand end to a rod 51 connected to the capsules 75. The capsules 75, Fig. 9, operate a lever 114, connected to rod 51, through a fluid pressure servomotor 102, a fall in pressure in the capsules 75 moving rod 51 to raise discs 27 to trim more tobacco off the filter. The brush 28 is adjusted simultaneously with the discs 27. The capsules 75 are connected to the control valve 80 of the servomotor which control ports 101, 102, in a follow-up sleeve 99 connected to a floating lever 119 pivoted at 120 to a lever 108 connecting a piston 104 to a link 111 operating the lever 114 which adjust the position of the discs 27. The link 111 is also connected through a lever 107 to a second piston 103. Movement of the valve 80 supplies pressure fluid to the upper or lower piston 103, 104, to move link 111, which movement adjusts follow-up sleeve 99. The position of the discs 27 is indicated on a scale 67, Fig. 6, and the changes in pressure in chamber 70 are indicated on a scale 117, Fig. 2. The lefthand end of the lever 42 is also adjusted by a #-ray device which measures the density of the cigarette rod at a point downstream of the trimming device 27. The ionisation current of the #-ray device 130, Fig. 5, is compared with that of a similar device 132 operating on a standard rod 134 and the resultant is amplified at 135 and operates a reversible electric motor 49 in one direction or the other to operate a worm 48 to raise or lower the left-hand end of rod 42, Fig. 6, thereby raising or lowering the discs 27 to correct the density of the filler. The air-permeability testing device 70 comprises a short-term device making immediate corrections for slight variations from normal whilst the #-ray device 130 forms a long-term correction device correcting for deviations of the average density of long lengths of the filler from normal. The reversible motor 49 may also adjust a change-speed device 137 to adjust the rate of feed of the tobacco by the device 5 to the filler forming means. The #-ray device operates motor 49 through a circuit similar to that described in Specification 781,867 [Group XXXV]. Specifications 781,041, 781,042, 854,36, 881,024, 895,733, 909,222 and 916,141 also are referred to.