Patent ID: 6581780
Filing Date: 2003-06-24
Classification: B07B,G01N

Abstract:
A system for controlling the operation of an item of equipment for processing materials to produce a product which includes aggregate materials of various particle sizes in a predetermined weight ratio, said system comprising:(A) a sampling device for obtaining a sample of the product from a predetermined location; (B) a gradation assembly comprising: (1) a base; (2) a plurality of gradation screens; (3) a frame that is rotatably mounted on the base and adapted to support the gradation screens in a first frame position in which the screens are disposed in a generally horizontal attitude in a stacked arrangement whereby each screen in the stack has screen openings that are smaller than those of the screen immediately above it in the stack, and in a second frame position in which the screens are disposed generally vertically; (4) means for vibrating the screens while the frame is in the first frame position; (C) a weighing pan that is adapted for measuring the weight of aggregate material; (D) means for rotating the frame from the first frame position to the second frame position; (E) means for sequentially depositing the aggregate material that is retained on each screen, or that passes through all of the screens, in the weighing pan; (F) means for determining the ratios of the weights of the amounts of the aggregate materials that are retained on each of the screens or that passes through all of the screens to the total weight of the sample; (G) means for determining if each of the ratios of the weights of the amounts of the aggregate materials that are retained on each of the screens or that passes through all of the screens to the total weight of the sample meets a predetermined standard; (H) means for adjusting the operation of the item of equipment if the ratio of the weight of the aggregate materials that are retained on any of the screens or that passes through all of the screens to the total weight of the sample fails to meet the predetermined standard.