Patent ID: 7044090

Claim:
A combustion-type power tool comprising: a housing having one end and a lower side; a head section closing the one end of the housing and formed with a combustible gas passage; a push lever provided to the lower side of the housing and movable upon pushing onto a workpiece; a cylinder secured to an inside of the housing; a piston slidably disposed in the cylinder and reciprocally movable in an axial direction of the cylinder, the piston dividing an interior of the cylinder into a lower cylinder chamber below the piston and an upper cylinder chamber above the piston; a combustion chamber frame movably provided in the housing, the combustion chamber frame being abuttable on and separable from the head section in interlocking relation to the movement of the push lever, a combination of the head section, the upper cylinder chamber, and the combustion chamber frame defining a combustion chamber; a first sealing section providing a sealing relation between the combustion chamber frame and the head section when the combustion chamber frame is brought into abutment with the head section; an ignition plug supported to the head section and having a spark generating portion exposed to the combustion chamber for igniting a mixture of air and the combustible gas in the combustion chamber, at least one of the spark generating portion and the first sealing section being a target to be cleaned during non-operational state of the power tool; the head section being formed with a cleaning passage having one end open to an atmosphere and another end open to the target to be cleaned; and a shut-off unit provided in the cleaning passage for shutting-off the cleaning passage from the atmosphere during fastener driving operation.