GB1119542A - Sorting machine - Google Patents

Abstract

1,119,542. photo-electric sorting apparatus. GUNSON'S SORTEX LTD. Jan. 9 1967 [Jan. 11, 1966], No. 1313/66. Heading G1A. [Also in Division G2] Objects to be sorted e.g. mineral particles suspended in a liquid pass through a hole 12 in a light integrating member 14 coated externally with an opaque material. At this hole, the feed conduit 10' is transparant allowing light to enter the holes from the ends of opaquely coated optical fibres 19 which are mounted between the two halves 15, 16 of the member 14. Light from a fibre is reflected or transmitted by a particle 11 into the light integrating member 14. The total light directed into the integrating member during the passage of a particle through the hole 12 is detected by a photo-multiplier located at a window 33 in the coating. The detector output is amplified and compared with a standard to decide whether or not the particle is to be sorted out by a moving coil or air-jet ejector. The light input to the optical fibres 19 is by means of a cathode ray tube 22 whose spot scans across the ends 21 of the optical fibres which are at this location cemented in a row to the screen. While a particle moves through the hole 12, the beam of the CRT sweeps across the ends 21 about three times. The effect is to produce a helical scanning of the particle 11 around about 90% of its surface. The arrangement of the optical fibres within the two halves of the integrating member is described, the arrangement being such as to produce narrow collimated beams issuing from ends 20 Fig. 4 (not shown). The whole sorting system is illustrated Fig. 1 (not shown).