Abstract: A device for tightening a bolt or a nut has a tightening socket which is releasable from biting engagement with the bolt or nut by disengaging a clutch in a rotation transmission system after completion of tightening, and which is made readily removable from the bolt or nut. The device is characterized in that it comprises power transmission means for coupling a socket drive motor to the socket for power transmission, the clutch incorporated in the power transmission means for selectively effecting or interrupting power transmission from the motor to the socket by a sliding movement, and clutch control means for selectively moving the clutch to an engaged position or a disengaged position. The clutch is moved to the disengaged position by the clutch control means after the motor is deenergized, whereby residual torque delivered by the motor to the bolt or the nut is removed to preclude biting engagement of the socket with the bolt or nut.

Abstract: A bolt tightening device for tightening torque controlled bolts each having at one end thereof a tip to be sheared has an outer socket engageable with a nut, and an inner socket engageable with the tip, the inner socket being axially slidable relative to the outer socket and biased outward by a spring, the two sockets being coupled to planetary gear mechanisms for delivering opposed torques to the respective sockets, a knockout pin extending into the inner socket for forcibly removing the bolt tip as sheared. The knockout pin for knocking out the sheared bolt tip is made contractable by being composed of a shank and a head provided on the shank and biased outward of the shank by a spring, The length of backward stroke of the knockout pin required for knocking out the tip is minimized by contracting the pin to thereby shorten the length of the device.

Abstract: 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.

Abstract: A bolt tightening device having an inner socket and an outer socket arranged coaxially with each other and coupled to a motor by planetary gear mechanisms for tightening a reaction-bearing bolt with a nut thereon by engaging the nut in the outer socket and a tip at one end of the bolt in the inner socket. The inner and outer sockets are coupled respectively to two output shafts of the gear mechanism in the terminal stage which are rotatable in directions opposite to each other. The terminal gear mechanism has an axis displaced from the axes of the other gear mechanisms in parallel thereto, and has two input shafts coupled to two output shafts of the other gear mechanisms by way of first and second idle gears, respectively. This construction reduces the axial thickness of the socket side of the device, rendering the device easy to use.

Abstract: A device comprises a housing having a planetary gear reduction mechanism accommodated therein and a handle projecting therefrom, an electric motor or like rotation source attached to the housing for inputting power to the reduction mechanism, an outer socket coupled to an internal gear of the reduction mechanism and engageable with a nut, an inner socket coupled to a planetary gear support frame of the reduction mechanism and engageable with a bolt tip, and a torque detecting control mechanism for detecting a nut tightening force to discontinue supply of power to the rotation source upon the tightening force reaching a predetermined value. A friction ring is provided between the housing and the support frame coupled to the inner socket to effect frictional engagement therebetween. A definite axial tension is available by rotating the outer socket, i.e., the nut, with the inner socket in a fixed state.

Abstract: A device for tightening up nuts on torque-controlled bolts comprising an inner socket first output gear rotatably disposed within a housing, an outer socket second output gear rotatably disposed coaxially with the first output gear, an inner socket first input gear rotatably disposed on an axis parallel to the axis of the first and second output gears and meshing with the first output gear, and an outer socket second input gear rotatably disposed coaxially with the first input gear and meshing with the second output gear. The first and second output gears respectively have shafts projecting therefrom in the form of concentric circles to provide socket fitting portions at outer ends of the respective shafts. The first and second input gears respectively have shafts projecting therefrom in the form of concentric cir cles to provide coupling portions at outer ends of the respective shafts for connection to output shafts of a power tightening device.

Abstract: A bolt tightening device comprising a main body including a tubular case and a cylindrical housing attached to the base end of the tubular case approximately at a right angle therewith, the case being provided with an outer socket for a nut to fit in and an inner socket for fitting the tip of a bolt therein, a main handle fixed to the main body, and an auxiliary handle attached to the main body and having a grip approximately parallel to the cylindrical housing. The auxiliary handle is withdrawable from the housing toward the sockets and detachably engageable with positioning portions provided in or on the main body to clamp the main body when in a withdrawn position and in a pushed-in position.