PURPOSE: To obtain a large operation torque of a torque limiter by uniformly arranging plural springs on the circumference on the side face of a pulley and idly rotating a cover which is in contact with said springs, together with an inside pulley, when a torque larger than the torque by said springs is generated.

CONSTITUTION: A wire wind-up pulley which is installed on the shaft 16 of a speed-reducing normal/reverse rotation motor 9 is formed in a double circle pulley in which an outer pulse 2 is rotated being in contact with the outer peripheral face of an inner pulley 1, and plural small diameter coil springs 3 are housed in an annular recessed hold 4 on the side face of the outer pulley 2. A receiver 6 and a cover 7 which hold and press the outer pulley 2 and the springs 3 in between from both side faces are clamped by bolts 8 and connectingly fastened to the inner pulley 1. When a motor torque larger than the outer-pulley side face pressing pressure of the springs 3 by means of the cover 7 and receiver 6 acts on the inner pulley 1, the cover 7 slides on a friction plate 5 which covers the heads of the springs and the receiver 6 also slides. Hence, they serve, together with the inner pulley 1, as an idle rotating torque limiter enabling a large torque limiter operation torque to be obtained.