Abstract: The disclosure provides a work tool having an electric motor, a power transmission means that receives motive power from the electric motor and transmits the motive power to a tip tool, a gear housing for accommodating at least a portion of the power transmission means, weights swingably supported on the gear housing, and coil springs that function as an urging means for urging the weights such that the weights are located at an initial neutral position, wherein the weights and the coil springs are provided respectively on the two sides of the gear housing so as to put the power transmission means therebetween, and a rotational support axle is provided that functions as a connecting means for connecting the weights provided on both sides of the gear housing so as to connect the weights such that the weights swing integrally.

Abstract: An electric power tool has a brushless motor for driving a tip tool, and a motor case is at least partly covered by a motor housing made of aluminum alloy and exposed to an outside. A control board provided with a control circuit for controlling the rotation of the brushless motor is disposed adjacent to the motor housing. The brushless motor and a control board are cooled by cooling air generated by a fun, thereby enhancing the cooling characteristics of the motor control circuit.

Abstract: Provided is a reciprocating work machine capable of further reducing vibration transmitted from a housing to a handle. The reciprocating work machine provided with an electric motor, a piston and a striker reciprocating by power of the electric motor and striking a tool, and a housing accommodating the electric motor, the piston, and the striker, includes: a resin handle operably connected to the housing; a spring provided between the housing and the handle and expanding and contracting in a reciprocating direction of the piston and the striker when the handle operates relative to the housing; and a weight provided to the handle and made of a material having a specific gravity higher than each of a specific gravity of a material constituting the handle and a specific gravity of a material constituting the housing.

Abstract: The disclosure provides a work tool having an electric motor, a power transmission means that receives motive power from the electric motor and transmits the motive power to a tip tool, a gear housing for accommodating at least a portion of the power transmission means, weights swingably supported on the gear housing, and coil springs that function as an urging means for urging the weights such that the weights are located at an initial neutral position, wherein the weights and the coil springs are provided respectively on the two sides of the gear housing so as to put the power transmission means therebetween, and a rotational support axle is provided that functions as a connecting means for connecting the weights provided on both sides of the gear housing so as to connect the weights such that the weights swing integrally.

Abstract: An electric power tool has a brushless motor for driving a tip tool, and a motor case is at least partly covered by a motor housing made of aluminum alloy and exposed to an outside. A control board provided with a control circuit for controlling the rotation of the brushless motor is disposed adjacent to the motor housing. The brushless motor and a control board are cooled by cooling air generated by a fun, thereby enhancing the cooling characteristics of the motor control circuit.

Abstract: A shuttering used for forming concrete comprises a plate with a plurality of through holes opening on both its face and reverse, and a double woven fabric consisting of a face tissue which permits passage of water but prevents concrete from passing and a reverse tissue opposed to the face of the plate and relatively displaceable with respect to the face of the plate; the surplus water oozing out of placed concrete flows through gaps formed by the reverse tissue between said plate and the face tissue as well as the through holes of said plate.