| 摘要 |
An electric hand held impulse wrench comprises a housing (10), a motor (12) with a rotor (18) and a stator (17), an pulse unit (13) and an output shaft (14), wherein the output shaft (14) together with pulse unit (13) and the rotor (18) are axially displaceable relative to the housing (10) between a forward rest position and a rear active position, and a spring (23) is employed to exert a bias force onto the pulse unit (13) in the forward direction towards the rest position. A manual application of a forward directed push force on the housing (10) to obtain engagement with a threaded fastener to be tightened the pulse unit (13) including the output shaft (14) and the motor rotor (18) are displaced rearwards in the housing (10), wherein a sensor (28) is arranged to be activated to generate a signal to initiate power supply to the motor (12) via a power control unit (32). The sensor (28) may be located either at the rear of the housing (10) to cooperate with the rotor (18) or at a forward position to cooperate with the pulse unit (13). |
