An electric nail gun includes a cylinder unit, a nail-striking unit and a valve unit. The cylinder unit includes a striking cylinder that surrounds a first axis and that defines a cylinder chamber, and a cylinder lid that cooperates with the striking cylinder to define a gas storing chamber communicating with the cylinder chamber. The cylinder lid includes a passage that communicates with the gas storing chamber, and that extends along a second axis. The nail-striking unit includes a piston assembly that is adapted for striking a nail. The valve unit includes a valve assembly that is accommodated in the passage. The valve assembly is operable to convert between a first state, in which the gas is allowed to flow between the gas storing chamber and an external environment through the passage, and a second state, in which the gas is refrained from flowing through the passage.

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.

A fastener driver including a main housing, a drive blade movable from a retracted position to a driven position for driving a fastener into a workpiece, and a gas spring mechanism for driving the drive blade from the retracted position to the driven position. The gas spring mechanism includes a cylinder housing containing a pressurized gas, and a piston movable relative to the cylinder housing and biased by the pressurized gas from a retracted position toward a driven position. The cylinder housing is displaceable along a longitudinal axis of the piston relative to the main housing and away from the drive blade, while the piston remains stationary relative to the main housing, to reduce the pressure of the pressurized gas within the cylinder housing.

A fastener driver including a main housing, a drive blade movable from a retracted position to a driven position for driving a fastener into a workpiece, and a gas spring mechanism for driving the drive blade from the retracted position to the driven position. The gas spring mechanism includes a cylinder housing containing a pressurized gas, and a piston movable relative to the cylinder housing and biased by the pressurized gas from a retracted position toward a driven position. The cylinder housing is displaceable along a longitudinal axis of the piston relative to the main housing and away from the drive blade, while the piston remains stationary relative to the main housing, to reduce the pressure of the pressurized gas within the cylinder housing.

A fastener driver includes a drive blade movable from a retracted position to a driven position for driving a fastener into a workpiece and a gas spring mechanism for driving the drive blade from the retracted position to the driven position. The gas spring mechanism includes a piston movable between a retracted position and a driven position. The fastener driver further includes a first return mechanism for moving the drive blade from the driven position toward the retracted position, and a second return mechanism for moving the piston from the driven position toward the retracted position.

A fastener driver includes a drive blade movable from a retracted position to a driven position for driving a fastener into a workpiece and a gas spring mechanism for driving the drive blade from the retracted position to the driven position. The gas spring mechanism includes a piston movable between a retracted position and a driven position. The fastener driver further includes a first return mechanism for moving the drive blade from the driven position toward the retracted position, and a second return mechanism for moving the piston from the driven position toward the retracted position.

A pneumatic fastening tool that has an integrated valve assembly. The integrated valve assembly can have a cylindrical valve assembly housing that can house a portion of a head valve assembly and can also house at least a portion of a trigger valve assembly. The head valve assembly can have a head valve body that can be maintained in a resting state by compressed air. The compressed air that maintains the resting stat of the head valve assembly can be provided by one or more passages formed in the valve assembly housing. The valve assembly housing can also guide the movement of the valve head body when the trigger valve assembly is actuated causing a fastener to be driven into a workpiece. The valve assembly housing can have a circular exhaust seal and a cylindrical exhaust chamber through which compressed air can be exhausted after the driving of a fastener into a work piece.

A fastener driving tool including a housing enclosing a cylinder having a lower end with a resilient bumper, a return air chamber in communication with the lower end of the cylinder and a piston dimensioned for reciprocation within the cylinder to impact the bumper and having a driver blade depending therefrom. At least one inlet opening is in communication with the return air chamber and at least one outlet opening is disposed in the cylinder and spaced from the at least one inlet opening. The at least outlet opening is in communication with the return air chamber and aligned with the piston so that each outlet opening is closed by the piston to seal the cylinder as the piston impacts the bumper and traps a residual volume of air in the cylinder below the piston to damp impact of the piston upon the bumper.

A driving tool includes a first cylinder that generates compressed air by reciprocating movement of a first piston slidably disposed therein. A longitudinal direction of the first cylinder intersects a longitudinal direction of a second cylinder and extends alongside a magazine that feeds fasteners onto an axis of movement of a driving part of a second piston. The first piston reciprocally slides in a direction that extends alongside the magazine. A tool handle is disposed on the side of the first cylinder that is opposite from the magazine in the direction of the axis of movement.

A driving tool includes a first cylinder that generates compressed air by reciprocating movement of a first piston slidably disposed therein. A longitudinal direction of the first cylinder intersects a longitudinal direction of a second cylinder and extends alongside a magazine that feeds fasteners onto an axis of movement of a driving part of a second piston. The first piston reciprocally slides in a direction that extends alongside the magazine. A tool handle is disposed on the side of the first cylinder that is opposite from the magazine in the direction of the axis of movement.