摘要 |
An electric wrench includes a motor (10), an electromagnetically controlled clutch (70) comprising electromagnet members (71) and a temporary magnetizable member (72). A centrifugal control switch (82) is provided to de-energize the electromagnet members (71) when the drive shaft (30) connected to the motor (10) spins at a predetermined rate of rotation and to energize the electromagnet members (71) when the drive shaft (30) spins slower than the predetermined rate of rotation. The centrifugal control switch (82) is actuated by a centrifugal swinging device (81). <IMAGE> |