Patent ID: 8839958

Claim:
A method for screening materials, comprising: providing a device for screening materials, the device including a body; a meshed screening deck; a fastening frame for the screening deck; at least two horizontal eccentric shafts supporting the screening deck on the body, where the eccentric shafts are configured to be driven relative to the body; and a motor configured for rotating the eccentric shafts; wherein each eccentric shaft is bearing-mounted on the body with a first bearing such that a rotation axis of the eccentric shaft extends through a midpoint of the first bearing; and each eccentric shaft is bearing-mounted on the fastening frame of the screening deck with a second bearing such that a throw axis that is spaced from the rotation axis of the eccentric shaft extends through the midpoint of the second bearing; the device being configured so that when the device is operating each throw axis revolves around the corresponding rotation axis along a circular path continuously in the same direction, the joint center of mass of movable structural components is disposed substantially along a plane that extends through and includes the rotation axes, and all mass forces of structural components are balanced with respect to the rotation axes; and driving the meshed screening deck upon the horizontal eccentric shafts, where the meshed screening deck is driven by machine power eccentrically with respect to the rotation axes, thereby forcing each point of the screening deck to revolve in continuous motion in the same rotational direction along a circular path.