GB1323559A - Separating out foreign bodies - Google Patents

Abstract

1323559 Stripping cigarettes BAT CIGAR ETTEN-FABRIKEN GmbH 10 Sept 1970 [15 Sept 1969] 43303/70 Heading A2C [Also in Divisions B2 and G1] Foreign bodies, such as small pieces of cigarette or packet paper, are sorted out from tobacco fleece coming from a ripping machine. General system. Tobacco fleece from the ripping machine is first reduced by sieving using a sieve conveyer or gutter with a 3 mm mesh, which passes about 90% of the material. The remaining fleece is long-fibred tobacco and foreign bodies. This material is passed on high speed conveyer 2 first to a spiked roller, whose distance from the conveyer is adjustable and is rotated at a speed somewhat less than that of the belt. The angled spikes spear filter plugs and cigarette lengths, which are removed by comb 4 and via channel 5. Alternatively an inclined roller or spiked belt is used at this stage. Photoelectric system. This represents the final sorting stage. Fluorescent lamps 8 illuminate the pieces of paper which contrast strongly with the brown tobacco and black conveyer belt surface. The lamps are energized at a high frequency and the detector circuit contains a filter to cut out this frequency. Reflected light passes via lenses 9, filters 10 matched to the lamp spectral range, prisms 11 to photocells 12 having similar spectral response to the filter pass band. The chosen wavelength is one which is not strongly reflected by the tobacco, but is by the foreign bodies. Reflected intensities above a certain threshold cause one or more electromagnetically controlled flaps 14 to be raised and allow the foreign body to be sucked into common exhaust chute 15.