Abstract: A tightening device including a transmission having an engageable/disengageable additional gear train. The additional gear train includes an epicyclic train with a toothed inner ring gear. The device includes engagement elements for engaging the additional gear train, able to take at least an engaged state and a disengaged state. A speed reducing ratio of the transmission is different depending on whether the additional gear train is engaged. The ring gear is mobile in translation along an axis of a rotor inside a casing of the device between: a free position, when the engaging elements are in the disengaged state and the ring gear is mobile in rotation relative to the casing so the additional gear train is disengaged; and a locked position, when the engaging element are in the engaged state and the ring gear is locked in rotation relative to the casing so the additional gear train is engaged.

Abstract: An impact screwing/unscrewing device includes: an electric motor having a rotor; a controller for controlling the motor, which can transmit an instruction to the motor; and an impact mechanism. The impact mechanism includes: at least one anvil mounted to rotate about the axis of rotation of the rotor; at least one hammer capable of being rotated by the motor about the axis, the hammer being movable between at least: a non-engaged position in which it is not capable of colliding with the at least one anvil when the hammer is rotated by the motor, and an engaged position in which it is capable of colliding with the at least one anvil when the hammer is rotated by the motor. A variation of the instruction supplied to the motor by the controller triggers passage of the at least one hammer from one of the positions thereof to the other.

Abstract: An impact screwing/unscrewing device includes: an electric motor having a rotor; a controller for controlling the motor, which can transmit an instruction to the motor; and an impact mechanism. The impact mechanism includes: at least one anvil mounted to rotate about the axis of rotation of the rotor; at least one hammer capable of being rotated by the motor about the axis, the hammer being movable between at least: a non-engaged position in which it is not capable of colliding with the at least one anvil when the hammer is rotated by the motor, and an engaged position in which it is capable of colliding with the at least one anvil when the hammer is rotated by the motor. A variation of the instruction supplied to the motor by the controller triggers passage of the at least one hammer from one of the positions thereof to the other.

Abstract: A screw driving device includes: a case; a motor provided with a rotor; an output member capable of driving in rotation an element for driving an element to be screwed; a transmission connecting the rotor to the output member, the transmission including at least one additional gear train capable of being engaged/disengaged; an motor controller. The device includes an element for engaging the additional gear train, which is capable of being in at least: an engagement state in which the additional train is engaged, and a disengagement state in which the additional gear train is not engaged. A reduction ratio of the transmission between the rotor and the output member is different according to whether or not the additional gear train is engaged, the reduction ratio being greater when the additional gear train is engaged.