US Patent 12083659 Unbalanced roller on lifting mechanism

A powered fastener driver includes a driver blade movable from a top-dead-center (TDC) position to a driven or bottom-dead-center (BDC) position for driving a fastener into a workpiece. The driver blade also includes a tooth defining an end portion. A drive unit provides torque to move the driver blade from the BDC position toward the TDC position. A rotary lifter is engageable with the driver blade and is configured to receive torque from the drive unit to return the driver blade from the BDC position toward the TDC position. The lifter has a drive pin and a roller positioned on and rotatable relative to the drive pin about a rotational axis. The roller includes a center of gravity that is offset from the rotational axis.