Combustion powered fastener driving tool

摘要

A piston velocity control and stability control system is provided for a combustion powered fastener driving tool (10) having a self contained combustion engine (16). The system includes a ring (48) that may be adjusted relative to exit ports (40) in a cylinder (22) of the combustion engine (16). The ring (48) includes openings (56) which may be incrementally aligned between a completely exposed, and a substantially closed position relative to the exit ports (40). Displaced air volume within the cylinder exits through the exit ports (40) as a piston (24) advances down the cylinder (22), and the velocity of the piston (24) will be greatest when the exit ports (40) are completely exposed. User initiated reduction of the effective size of the exit ports (40) by adjustment of the ring (48) will reduce the piston velocity. A nosepiece (34) used to guide the driver blade (28) and position the blade (28) over a fastener is isolated by means (64,65) from the cylinder (22) so that the nosepiece (34) remains stable relative to the workpiece upon combustion and until the driver blade (28) strikes the fastener. <IMAGE>