Patent ID: 6951194
Filing Date: 2005-10-04
Classification: B25C

Abstract:
1. A combustion-type power tool comprising: a housing having one end; a head section closing the one end of the housing and formed with a gas passage having one end functioning as a gas injection port for ejecting combustible gas and another end in communication with a gas canister; a combustion-chamber frame provided in the housing and movable in a lengthwise direction of the housing, the combustion-chamber frame having one end abuttable on the head section; a cylinder secured to the housing and in communication with an interior of the combustion-chamber frame, the cylinder guiding the movement of the combustion-chamber frame; a piston reciprocally movable with respect to the cylinder, a combination of the piston, the head section, the combustion-chamber frame and a head section side of the cylinder defining a combustion chamber when the one end of the combustion-chamber frame abuts on the head section; a motor supported on the head section; a fan secured to the motor and positioned in the combustion chamber, the fan being rotatable about a rotation axis; an ignition plug body supported by the head section and having an electrode positioned in the combustion chamber for igniting a mixture of air and the combustible gas; and an opposing electrode section provided in the combustion chamber and located closer to the head section than the fan to the head section, the opposing electrode section opposing to the electrode for generating a spark therebetween; wherein the opposing electrode section is supported by the head section at a supporting position positioned closer to the axis of the fan than the electrode to the axis of the fan, and the opposing electrode section protruding outwardly from the supporting position in a radial direction of the rotation axis.