Power tool

A powered fastener driver comprising:

• a housing defining a cylinder support portion and a motor housing portion;
• a cylinder within the cylinder support portion;
• a driver assembly configured to drive a fastener into a workpiece, the driver assembly including:
• a piston movable within the cylinder from a top-dead-center (TDC) position to a bottom-dead-center (BDC) position along a driving axis, thereby defining a stroke length measured from the TDC position to the BDC position on the driving axis, and
• a driver blade attached to the piston for movement therewith along the driving axis from the TDC position toward the BDC position for driving a fastener into a workpiece;
• a lifter operable to move the driver assembly from the BDC position toward the TDC position;
• a first seal coupled to a first location on the driver assembly;
• and
• a second seal coupled to a second location on the driver assembly,
• wherein the second seal is located at a distance of at least the stroke length from the first seal.

An impact power tool adapted to impart axial impacts to a tool bit, the impact power tool comprising:

• a housing;
• a motor supported by the housing;
• a spindle coupled to the motor for receiving torque from the motor to cause the spindle to rotate;
• and
• a reciprocating impact mechanism that is operable to create a variable pressure air spring within the spindle, the impact mechanism including:
• a striker received within the spindle that reciprocates along a reciprocation axis in response to the variable pressure air spring, and
• a piston that reciprocates along the reciprocation axis to induce the variable pressure air spring, the piston movable within the spindle from a top-dead-center (TDC) position to a bottom-dead-center (BDC) position along the reciprocation axis, thereby defining a stroke length measured from the TDC position to the BDC position along the reciprocation axis,
• wherein the piston includes a first seal and a second seal, and wherein the second seal is located at a distance of at least the stroke length from the first seal.