Lifter mechanism for a powered fastener driver

A powered fastener driver comprising:

• a driver blade movable from a top-dead-center position to a driven or bottom-dead-center position for driving a fastener into a workpiece;
• a drive unit for providing torque to move the driver blade from the bottom-dead-center position toward the top-dead-center position;
• a rotary lifter engageable with the driver blade, the lifter configured to receive torque from the drive unit in a first rotational direction for returning the driver blade from the bottom-dead-center position toward the top-dead-center position, the lifter having a body and a drive pin coupled to the body;
• a roller rotatably supported on the drive pin and configured to engage with a tooth of the driver blade when moving the driver blade from the bottom-dead-center position toward the top-dead-center position, wherein the roller includes an engagement section configured to receive an end portion of the tooth of the driver blade;
• and
• a means for aligning the engagement section of the roller with the end portion of the tooth on the driver blade to facilitate meshing between the end portion of the tooth and the roller,
• wherein the alignment means includes a spring that applies a force to the roller to maintain the roller in a first rotational orientation relative to the drive pin when the driver blade is moving from the bottom-dead-center position to the top-dead-center position,
• wherein a reaction force is applied to the roller from the driver blade in response to the driver blade approaching the top-dead-center position, and
• wherein the reaction force exceeds the force of the spring so the roller is able to rotate to a second rotational orientation relative to drive pin.