Patent ID: 6669026
Filing Date: 2003-12-30
Classification: B07B,Y10T

Abstract:
A portable screening plant having a screen that screens particulate matter positioned thereon, the screening plant comprising:(a) a housing to which the screen is mounted; (b) a prime mover mounted to the housing; (c) a pair of endless tracks mounted to the housing and having surfaces for seating against a ground upon which the screening plant rests, the tracks being drivingly linked to the prime mover for driving the tracks along the ground; (d) a driveshaft drivingly linked to the prime mover and rotatably mounted to the screening plant; (e) a weight having its center of gravity spaced from the driveshaft's axis of rotation, said weight being radially movably mounted to the driveshaft for moving radially outwardly under centrifugal force during rotation of the driveshaft at a rate greater than a preselected rate to form an eccentric that causes the driveshaft, and the screen mounted thereto, to vibrate; (f) at least one bias connected to the driveshaft and the weight, said bias biasing the weight's center of gravity toward closer proximity to the driveshaft's axis of rotation for returning the weight to a rest position when the driveshaft is rotating is at a rate less than a preselected rate; and (g) a plate rigidly mounted to the driveshaft and to which the weight is radially movably mounted.