Abstract: A gas spring-powered fastener driver includes an outer cylinder configured to contain a pressurized gas therein, an inner cylinder disposed within the outer cylinder, a piston disposed within the inner cylinder and moveable along the inner cylinder, a driver blade attached to the piston and moveable therewith between a top-dead-center (TDC) position and a bottom-dead-center (BDC) position, the driver blade configured to drive a fastener when moved from the TDC position toward the BDC position, and a two-way valve coupled to the outer cylinder. The two-way valve configured to selectively permit a first flow of gas into the outer cylinder and to selectively permit a second flow of gas from the outer cylinder.

Abstract: A gas spring-powered fastener driver includes a cylinder, a storage chamber cylinder having pressurized air in communication with the cylinder, a moveable piston positioned within the cylinder, a driver blade extending from a first side of the piston and movable therewith between a top-dead-center position and a bottom-dead-center position, a one-way seal carried onboard the piston and disposed between the piston and the cylinder, the one-way seal being configured permit a bypass flow of pressurized air from the first side of the piston, past the one-way seal, and into a space within the cylinder adjacent an opposite, second side of the piston during movement of the piston and driver blade from the top-dead-center position to the bottom-dead-center position, thereby increasing a pressure of the pressurized air within the cylinder and storage chamber cylinder, and a pressure relief valve in fluid communication with the storage chamber cylinder.