US Patent 7399383 Vibratory conveyor with non-biased oscillation

A vibratory conveyor has a bed or trough that carries the workpieces, and supported above a base plate. A vibratory motor employs linear bearing to provide vibratory that is kept in the plane of the conveyor bed. A directional fabric material lying on the trough is smooth or slippery in one direction but grips the workpieces in the opposite direction. The vibratory motor keeps the motion in the back and forth direction, with almost no vertical component, for quieter operation and without shaking that can damage delicate workpieces. The direction of motion can be selected by orienting the fabric.