Abstract: In an electric power tool having a clutch ring for adjusting a fastening torque, an outer member 3 which are lower in hardness than a base member 2 of the clutch ring 1 has a plurality of projections discontinuously arranged on the outer peripheral face of the base member 2.

Abstract: In an electric power tool having a clutch ring for adjusting a fastening torque, an outer member 3 which are lower in hardness than a base member 2 of the clutch ring 1 has a plurality of projections discontinuously arranged on the outer peripheral face of the base member 2.

Abstract: In a battery-driven tool, comprising a motor equipped with a fan and air windows arranged on the casing where the motor is positioned and for sending cooling air generated by rotation of the fan to outside, the object of the present invention is to send hydrogen gas generated by overdischarge to outside so that hydrogen gas is not accumulated in the battery chamber, and to exclude undesirable effect on the designing of the battery-driven tool. To attain the object, the motor chamber to accommodate the motor equipped with the fan is communicated with the battery chamber where the battery is accommodated.

Abstract: An electrically powered tool such as a drill has a gear holder drivable by a motor shaft and having a larger-diameter gear and a smaller-diameter gear, a transmission shaft rotatable by the gear holder for rotating an output shaft, the transmission shaft having a splined disc having first splines, a high-speed gear rotatably mounted on the transmission shaft and held in mesh with the larger-diameter gear, the high-speed gear having second splines, a low-speed gear rotatably mounted on the transmission shaft and held in mesh with the smaller-diameter gear, the low-speed gear having third splines, a pair of springs for normally urging the high- and low-speed gears to be axially held against opposite surfaces of the splined disc, and a clutch plate having internal axial teeth and axially slidably mounted on the splined disc.