Abstract: A combustion-type power tool includes a housing, a cylinder disposed, a piston, and a cylinder head disposed at an end of the housing and having a wall portion extending in a direction perpendicular to an axial direction, the wall portion having an opening. A motor is disposed at the cylinder head and includes a motor body and a drive shaft extending from the motor body into a combustion chamber through the opening of the wall portion of the cylinder head, a fan is connected to the drive shaft to be rotatable within the combustion chamber, and an elastic member is disposed at the opening of the wall portion and has a sleeve portion extending in the axial direction. The sleeve portion has a through-hole through which the drive shaft extends, and an inner surface of the through-hole is tapered with respect to an outer surface of the drive shaft.

Abstract: A combustion-type power tool includes a frame comprising a housing having one end, and a head portion disposed at the one end, and a piston reciprocally movably disposed in the housing. A combustion chamber is provided in the housing and has one end movable toward and away from the head portion and another end defined by the piston. A motor is provided and has a motor case disposed opposite to the combustion chamber with respect to the head portion, a buffer member is provided which supports the motor and has a part located between the motor case and the head portion.

Abstract: In the combustion-type power tool, a first shelter wall and a second shelter wall are disposed to partially surround an area between an ignition plug and an ignition ground. Two gaps are provided between the first and second shelter walls. The first shelter wall extends radially outwardly from an outer peripheral surface of a motor boss, and also protrudes from an end face in an axial direction of a fan shaft. The first shelter wall has a lower end surface inclined such that an axial length between the end face and the lower end surface is gradually reduced toward radially outer end of the first shelter wall.

Abstract: A spark is shot between an ignition point of an ignition plug and an ignition ground. The spark is shot from an acute corner of a core of the ignition plug. A tip end of the core has an acute angle of not more than 45 degrees. With this arrangement, an emitting point of the spark can be concentrated to the tip end of the core. In order to reduce a thermal capacity of the ignition ground so as to enhance ignitability, a side opposite to the spark seating face of the ignition ground is tapered to provide an angle. Further, the ignition ground has an apex end providing an angle which is not more than 45 degrees. Because of the apex portion, thermal capacity of the ignition ground can be reduced and an acute angle can be realized to concentrate spark receiving point at the apex portion. As a result, ignitability can be enhanced.

Abstract: A combustion-type power tool includes a housing, a cylinder, a cylinder head, a combustion chamber frame, and a rotatable fan. The combustion chamber frame including a base section, a head section abuttable on the cylinder head to provide a combustion chamber when the combustion chamber frame is at a first position, and a connection portion for connecting the head section with the base section. The fan includes fan blades which define a widthwise center line and having widthwise edge portions which define a widthwise edge line at a side of the cylinder head. The widthwise center line is offset from the connection portion toward another end of the housing, and the widthwise edge line is offset from the connection portion toward the cylinder head when the combustion chamber frame is at a second position.

Abstract: A combustion-type power tool includes a housing, a cylinder disposed, a piston, and a cylinder head disposed at an end of the housing and having a wall portion extending in a direction perpendicular to an axial direction, the wall portion having an opening. A motor is disposed at the cylinder head and includes a motor body and a drive shaft extending from the motor body into a combustion chamber through the opening of the wall portion of the cylinder head, a fan is connected to the drive shaft to be rotatable within the combustion chamber, and an elastic member is disposed at the opening of the wall portion and has a sleeve portion extending in the axial direction. The sleeve portion has a through-hole through which the drive shaft extends, and an inner surface of the through-hole is tapered with respect to an outer surface of the drive shaft.

Abstract: A combustion-type power tool having a cooling arrangement for cooling a cylinder. The tool includes a housing, a cylinder head at one end of the housing, a push lever disposed at another end of the housing, and a combustion chamber frame including a base section and a head section. The head section has a disc like connecting portion extending from an end of the base section and a sleeve like abutment section extending from the connecting portion toward a cylinder head. A fan is disposed in a combustion chamber and is fixed to a rotation shaft of a motor supported to the cylinder head. The fan has fan blades. The fan blades define a widthwise center line in the axial direction of the rotation shaft. The center line is offset from the connecting portion and toward the push lever. The fan blades define widthwise edges in confrontation with the cylinder head. The widthwise edge is positioned in alignment with the connecting portion or offset therefrom toward the cylinder head.

Abstract: A combustion type power tool having an arrangement avoiding direct striking of a drive shaft against a cylinder head when combustion pressure is exerted. A motor is disposed at the cylinder head and includes a motor body and a drive shaft extending in an axial direction and protruding into a combustion chamber. A fan is connected to the drive shaft to be rotatable within the combustion chamber. A buffer piece made from an elastic material is supported to the cylinder head. The buffer piece is movable relative to the cylinder head in a direction substantially perpendicular to the axial direction. The buffer piece is formed with a through-hole through which the drive shaft extends.

Abstract: A combustion-type power tool includes a cylinder and a combustion chamber frame disposed to surround the cylinder and movable along the cylinder. A partition wall divides an inner space of an outer frame into a first space in which the cylinder and the combustion chamber frame are disposed and a second space in which a gas cartridge cylinder is disposed and has a through-hole through which the first space and the second space are in fluid communication with each other. A plurality of ribs is formed on an outer surface of the cylinder for regulating an exhaust gas flow generated by combustion of a gaseous mixture in the combustion chamber. The ribs enable exhaust gas discharged from the combustion chamber to be directed away from the through-hole, thereby enabling the gas cartridge cylinder to be maintained at a substantially constant temperature.

Abstract: A combustion-type power tool includes a housing, a cylinder head disposed at one end of the housing, a cylinder in the housing, a piston slidably disposed in the cylinder, and a driver blade connected to the piston. A combustion-chamber is provided in the housing, a fan is disposed in the combustion chamber, and a motor having an output shaft is coupled to the fan. A motor holder accommodates the motor, and the cylinder head is formed with a motor holder receiving portion in which the motor holder is slidably movably disposed. An elastic member is disposed in a gap formed between the motor holder and the motor holder receiving portion.

Abstract: A combustion-type power tool includes a frame comprising a housing having one end, and a head portion disposed at the one end, and a piston reciprocally movably disposed in the housing. A combustion chamber is provided in the housing and has one end movable toward and away from the head portion and another end defined by the piston. A motor is provided and has a motor case disposed opposite to the combustion chamber with respect to the head portion, a buffer member is provided which supports the motor and has a part located between the motor case and the head portion.

Abstract: A combustion-type power tool having a cooling arrangement for cooling a gas canister. The tool includes a housing having a gas canister accommodating section in which a gas canister is accommodated. An air passage is defined between the gas canister accommodating section and the gas canister accommodated therein. The gas canister accommodating section is formed with an air inlet port in communication with the air passage for introducing air into the air passage. Since air flows along the gas canister, the gas canister can be cooled. If the tool is provided with a fan, the rotation of the fan causes air suction passing through the air passage.

Abstract: A combustion-type nail driver uses a motor for driving a fan. A motor holder formed from plastic accommodates the motor. A cylinder head has a motor holder receiving portion in which the motor holder is slidably movably disposed. A coil spring has one end secured to the motor holder and another end secured to the cylinder head to thereby support the motor holder. Initial acceleration applied to the motor when combustion occurs can be suppressed and impact imparted upon the motor can also be suppressed by friction between the outer periphery of the motor holder and the inner periphery of the motor holder receiving portion. A heat shielding plate is interposed between the lower end surface of the motor and the cylinder head in order to prevent hot air combustion gas from entering into the motor.

Abstract: A combustion-type power tool includes a housing, a head portion, a cylinder disposed in the housing, and a push lever. A piston is reciprocally movable in the cylinder, and a combustion-chamber frame is disposed in the housing and abuttable on the head portion to provide a combustion chamber in cooperation with the head portion and the piston. A fuel supplying portion supplies the fuel into the combustion chamber, a motor is disposed at the head portion, and a fan is disposed in the combustion chamber and connected to an output shaft of the motor so as to promote turbulent combustion of an air-fuel mixture. The fan and the combustion-chamber frame define a high turbulent-combustion region and a low turbulent-combustion region, a fin of one shape is located within the low turbulent-combustion region, and another fin of another shape has a part thereof located in the high turbulent-combustion region.

Abstract: A main switch section is accommodated in a trigger. The trigger provided on the handle through a spring. The handle is formed with a recess to which one end of the spring is seated, so that the trigger is normally urged toward the lower side of the combustion-type nail driver. A switch accommodating portion is provided in the lower side of the canister housing. A push switch is stored in the switch accommodating portion.

Abstract: In the combustion-type power tool, a first shelter wall and a second shelter wall are disposed to partially surround an area between an ignition plug and an ignition ground. Two gaps are provided between the first and second shelter walls. The first shelter wall extends radially outwardly from an outer peripheral surface of a motor boss, and also protrudes from an end face in an axial direction of a fan shaft. The first shelter wall has a lower end surface inclined such that an axial length between the end face and the lower end surface is gradually reduced toward radially outer end of the first shelter wall.

Abstract: A spark is shot between an ignition point of an ignition plug and an ignition ground. The spark is shot from an acute corner of a core of the ignition plug. A tip end of the core has an acute angle of not more than 45 degrees. With this arrangement, an emitting point of the spark can be concentrated to the tip end of the core. In order to reduce a thermal capacity of the ignition ground so as to enhance ignitability, a side opposite to the spark seating face of the ignition ground is tapered to provide an angle. Further, the ignition ground has an apex end providing an angle which is not more than 45 degrees. Because of the apex portion, thermal capacity of the ignition ground can be reduced and an acute angle can be realized to concentrate spark receiving point at the apex portion. As a result, ignitability can be enhanced.

Abstract: A combustion type power tool having a motor suspension arrangement capable of buffering a shock applied to a motor. An integral buffer member made from an elastic material is fixed to a head cap. The buffer member includes a motor storage section in which a motor casing is stored, and a plurality of buffer segments extending radially outwardly from the motor storage section and integrally therewith. Each radially outer end portion of each buffer segment is fixed to the head cap for floatingly supporting the motor storage section.

Abstract: A combustion-type power tool includes a cylinder and a combustion chamber frame disposed to surround the cylinder and movable along the cylinder. A combustion chamber is formed on top of the cylinder that accommodates a gaseous mixture of existing air in the combustion chamber and fuel injected therein from a gas cylinder. A spark plug generates a spark to combust the gaseous mixture in the combustion chamber. A trigger switch produces the spark in the spark plug when operated. A piston slidably moves along the inner surface of the cylinder and driven by combustion in the combustion chamber. A driving blade is secured to the piston for driving a fastener. A partition wall divides the inner space of the outer frame into a first space in which the cylinder and the combustion chamber frame are disposed and a second space in which the gas cylinder is disposed. The partition wall is formed with a through-hole through which the first space and the second space are in fluid communication with each other.

Abstract: A combustion-chamber frame is disposed in a housing of a combustion-type power tool and is movable in a longitudinal direction in interlocking relation to a push lever. The combustion-chamber frame is abuttable on a head portion to provide a combustion chamber in cooperation with the head portion and a piston. A fan is disposed in the combustion chamber and is connected to an output shaft of a motor so as to be rotatable with the output shaft for promoting turbulent combustion of air-fuel mixture. The fan and the combustion-chamber frame define, within the combustion chamber, a high turbulent-combustion region in which the turbulent combustion is rapidly generated and a low turbulent-combustion region outside the high turbulent-combustion region. A fin is disposed at at least one of the combustion-chamber frame, the head portion, and the piston to protrude into the combustion chamber. The fin is located within the low turbulent-combustion region.