To prevent deterioration of failure strength due to wear of a rotation restriction pin used as a safety pin failed when hoisting winch hangs and large rewinding force joins the suspension line.

The hoisting winch 1 is prepared by fitting the winding up barrel 6 of the suspension line 8 on a main shaft 3 which carried out bearing to a case 2; providing an internal gear 7 at a side surface of the winding up barrel 6; fitting the external gear 10 to an eccentric cam 9 prepared in the main shaft 3; engaging the internal gear 7 and the external gear 10 in inside and outside; providing a rotation regulating plate 11 at a side face of the external gear 10 side surface; and projecting a rotation restriction pin 15 in a case 2. A projection pin part 16 of a rotation restriction pin 15 receives the force from the rotation regulating plate 11, if rewind force is added to the suspension line 8, is set to the strength where a root part 17 is destroyed, and used also the safety pin, if the rewinding force is larger than the normal use time. In the projection pin 16, the root part 17 is made thinner than a tip end 18. The tip end 18 is made a friction part against which the rotation regulating plate 11 contacts and is ground. The root part 17 is made a failure strength determination part which is not ground against the rotation regulating plate 11 and is not rubbed.