| 摘要 |
PURPOSE:To make slip torque constant and perform quick winding operation by driving a driven part by the use of a coil spring which has a loosening habit with respect to the rotating direction of a driving member. CONSTITUTION:A spool body 12 having a driving member 9 and a driven part 14 is rotatably fitted onto a spool shaft 1, and a coil spring 10 is wound in close contact to the member 9. The leading end 11 of said spring is fitted into the hole 13 of the part 14. The spring 10 is wound in the loosening direction during rotation of the member 9. With this constitution if the member 9 is turned by the operation of a winding lever, the part 14 is also turned and wound by way of the spring 10. When the winding of the film is oversized, large load is exerted upon the spring and therefore the spring 10 becomes loose and rotates in the same direction as that of the member 9 while producing slips, thereby surely winding the film. Since the coefft. of friction has nothing to do with the factors for slip torque of this case, the slip torque is constant and the stable winding is accomplished. |
