| 摘要 |
A powered nailer (10) includes a power source (12) including a driving element (16) reciprocating within a cylinder (14) between a pre firing position and a fastener driving position, the latter occurring when the driving element engages a bumper (20) disposed at the bottom (22) of the cylinder (14). A reciprocating valve element (40) defines a combustion chamber (30) in fluid communication with the cylinder (14), and is configured for receiving a dose of fuel and air prior to a user-generated ignition. A return chamber (52) at least partially surrounds the cylinder (14) and is in fluid communication with the cylinder (14), being configured for receiving a supply of pressurized air generated by the driving element (16) as it moves from the prefiring position to the fastener driving position, the pressurized air acting on an underside of the driving element (16) for returning it to the pre-firing position. |
