Patent GB-958236-A (GB)
Title: Improvements in or relating to control apparatus for cigarette-making machines
IPC: A24C5/34
Filed: 1960-12-20
Abstract: 958,236. Cigarette-making machines. AMERICAN MACHINE & FOUNDRY CO. Dec. 20, 1960 [Dec. 30, 1959], No. 43791/60. Heading A2C. [Also in Divisions B8, G1 and G3] Tobacco added to the main tobacco stream on the hopper belt 12, Fig. 1, of a continuous-rod machine, by a mechanism 87 so controlled by a dectector 83 as to rectify short-term irregularities in the stream, is extracted from the main hopper shower 11 by a gutter 16 whose projection thereinto is so controlled by a detector 132 as to rectify long-term irregularities in the stream. A screw conveyer 44 feeds the tobacco intercepted by the gutter 16 to a jigging conveyer 56 delivering to the mechanism 87, which comprises a vibrated hopper 80, picker rollers 100, 104 and a shoot 106. Over-filling of the hopper 80, as detected by a photo-cell 136, acts via an electronic amplifier 140 both on a solenoid 142 to move the delivery end of the conveyer 56 over a shoot 82 and on the reversing controller 146 of a motor 86 to cause a roller 84 to rotate clockwise instead of counterclockwise, tobacco being then returned to the shower 11 via a jigging conveyer 148 and a pneumatic system 152 having a blower 154. The detector 132 is an ionization chamber coacting with X-rays from a source 130 and, according to the density of the tobacco stream as measured over several seconds, acting through an amplifier 134 on a reversible motor 64 to turn a screwed shaft 68 carrying a nut 40 having a spring- cushioned connection (Fig. 4, not shown) to the gutter 16. The conveyer 44 moves with the gutter 16 and is driven by a motor 52 mounted on the nut 40. A shield plate and resilient gutter seal (not shown) protects the mechanism 40, 42 from tobacco dust, and its travel is controlled by limit switches disconnecting motor 64 during excessive tobacco over-feed or under-feed. The hopper 80 is vibrated by an A.C. coil and the conveyer 56 by an A.C. solenoid in conjunction with a double-decker leafspring suspension (Fig. 3, not shown). The conveyer 148 is similarly vibrated and may have a single-decker leaf-spring suspension. The detector 83 is a dielectric or radiation gauge of sufficiently fast response to correct short-term variations in the weight of individual cigarettes, and acts via a detector-preamplifier stage 88 and an amplifier 90 on a servometer 92 acting to superimpose on the constant-speed input of a differential 94 a variable input and give a variable-speed output drive 98 to the picker roller 100. The roller 104, Fig. 9, is driven at constant speed and has pins 116 mounted on helical vanes 120 acting as air blowers. The shoot 106 is positioned where the belt 12 is already bent into "U" shape and just before it passes beneath a compression wheel preparatory to transfer to the usual paper web entering the rod former. The roller 104 may be driven by the main machine drive or by a separate motor also driving the compression wheel and, through gears, the constant-speed differential input. The gutter 16 may extract 20% of the shower 11. The detector 135 may be positioned at any point downstream of the shoot 106, either before or after rod formation, and preferably between the rod sealer and cut-off.