摘要 |
An electric wrench includes a motor, an electromagnetically controlled clutch comprising electromagnet members and temporary-magnetizable members, a centrifugal control switch to de-energize the electromagnet members when the drive shaft connected to the motor spins at a predetermined rate of rotation and to energize the electromagnet members when the drive shaft spins slower than the predetermined rate of rotation, and a centrifugal swinging device for actuating the centrifugal controlled switch.
|