US Patent 10569403 Gas spring fastener driver

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.