Patent ID: 6401933
Filing Date: 2002-06-11
Classification: B07B

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) at least two wheels rotatably mounted to the housing and having rolling surfaces seated against a ground upon which the screening plant rests for supporting the housing during towing of the screening plant over the ground; (c) a hitch pin rigidly mounted to the housing for connecting the housing to a towing vehicle for towing the screening plant; (d) a motor mounted to the housing; (e) a driveshaft drivingly linked to the motor and rotatably mounted to the screening plant; (f) 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; and (g) 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 at a rate less than a preselected rate.