US Patent 7584723 Combustion powered fastener-driving tool with interconnected chambers

A combustion tool has a combustion-powered power source including a cylinder encircling a reciprocating piston associated with a driver blade, and having at least one air port located at a bumper end of said power source located below the piston. At least one air intake is in fluid communication with the power source and is provided with an associated air filter. At least one air passageway is provided in fluid communication with the at least one air port and in operational relationship with the air filter.