Automatic gradation unit
US6581780B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 16, 2001 |
| Grant date | Jun 24, 2003 |
| Priority date | — |
| Expiry date | Apr 27, 2021 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2015/0096
- WIPO fieldMeasurement
- WIPO sectorInstruments
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 includes a sampling device for obtaining a sample of the product from a predetermined location and a gradation assembly. The gradation assembly includes a plurality of gradation screens and a weighing pan for measuring the weight of aggregate material. The gradation screens are supported by a frame in a generally horizontal attitude in a stacked arrangement, so that each screen in the stack has screen openings that are smaller than those of the screen immediately above it in the stack. The assembly also includes a vibrator for vibrating the screens and a mechanism for sequentially depositing the aggregate material that is retained on each screen or that passes through all of the screens in the weighing pan. The system determines 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, and compares each of the ratios so determined to a predetermined standard…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.