METHOD AND DEVICE FOR SIZE-GRADING OF GRAIN MATERIALS Russian patent published in 1994 - IPC

FIELD: separation of friable materials. SUBSTANCE: during reciprocating motion of screen the brushes are made to move so that they periodically break contact with screen surface. Grains sticking in screen meshes are acted upon when screen stops in the lowermost position, inclining brush axles along screen trajectory. This nature of motion is provided for by introducing crank gear, ratchet mechanism and vertical endless chain into brush cleaner drive. EFFECT: improved functional and operating characteristics. 2 cl, 1 dwg