US Patent 8636185 Fastener advance delay for fastener driving tool

A nailer includes a power source including a piston reciprocating within a cylinder, a driver blade secured to the piston for common movement relative to a nosepiece, a magazine connected to the nosepiece for feeding fasteners sequentially for being driven into a workpiece by the driver blade, a delay mechanism operatively associated with the magazine and configured for engaging a second fastener and delaying advancement of the subsequent fastener to the nosepiece until the driver blade returns to the pre-firing position after driving a leading fastener.