Device for tightening bolt and nut

摘要

A device for tightening a bolt and a nut including a housing having a planetary gear reduction mechanism accommodated therein, a rotational drive source attached to the housing for inputting power to the reduction mechanism, an inner socket coupled to one of two output shafts of the reduction mechanism and engageable with a tip at an end of the bolt, an outer socket coupled to the other output shaft of the reduction mechanism and engageable with the nut, and a torque sensor for detecting a predetermined tightening torque of the outer socket. An actuated brake is disengageably coupled to a rotation transmitting system for the inner socket, whereby fasteners of the one side type can be tightened up efficiently with safety.