GB1067121A - Device and method for grading loose granules - Google Patents

Abstract

1,067,121. photo-electric sorting by weight. VSESOJUZNY NAUCHNOISSLEDOVATELJSKY INSTITUTE BUROVOI TEKHNIKI. May 25, 1964, No.21434/64. Headings G1A and G1W. An automatic device for grading loose granules by weight comprises weighing means, a feeder for delivering single granules to the weighing means, a table having a plurality of compartments for receiving graded granules, delivery means for delivering each weighed granule from the weighing means to the correct compartment, said delivery means and the table being rotatably mounted with respect to each other and the compartments arranged such that the compartment to which the weighed granule is delivered depends on the relative angular positions of the table and the delivery means, and automatic control means for setting said relative angular positions in response to the weight of each respective granule. Diamonds to be graded are fed to a hopper 12, Fig. 3, one diamond 20 is entrapped on a hole 19 in a piston 14 by a vacuum inside the piston and the piston itself is withdrawn to an upper position by a vacuum in the chamber 16. When the aperture 23 in the piston 14 comes opposite an aperture in the casing 3 the vacuum within the piston is released and the diamond 20 falls down a shoot 24 to a scale pan 10. The torsion balance beam 11 Fig. 4 to which the scale pan is attached carries a vane 40 which interrupts light from a source 38 to a detector 39. The output of detector 39 is amplified and drives a motor 37 which winds or unwinds a torsion spring 6 to bring the vane 40 into an equilibrium position. At the same time motor 37 drives a disc 4 carrying a plurality of receptacles 5 so that a receptacle corresponding to the weight of the diamond is positioned below a shoot 25. A solenoid 34 is then energized to knock the diamond from the scale pan down the shoot 25 into the appropriate receptacle 5. The pneumatic system 43 is then actuated to supply another diamond to the scale pan.