US Patent 7572082 Bearings for the vibration-causing assembly of a vibrating screed

A vibrating device for surfacing concrete comprising a surfacing blade, a vibration-causing assembly in communication with the surfacing blade and an actuator in communication with the vibration-causing assembly for imparting a vibratory motion to the blade. The vibration-causing assembly comprises a shaft assembly and a bearing assembly in communication with said shaft assembly. The bearing-assembly provides for substantially avoiding undesired movement of said blade during the vibratory motion.