| 摘要 |
PURPOSE:To provide proper gearing in a sprocket gear rotated by gearing with perforations in a film, by providing unequal radial clearance of the sprocket gear corresponding to varying load moment. CONSTITUTION:A sprocket gear 14 is rotated counterclockwise by perforations in a film. Then, the perforations in the film receives the largest load moment when they gear with second and third sprocket teeth 15b, 15c to enlarge elastic deformation of the perforations due to the teeth 15b, 15c. In contrast with these teeth, the interval between first and second sprocket teeth 15a, 15b acting on the initial rotation having small load moment is enlarged so that the respective intervals between the second, third and fourth sprockets teeth 15b-15d acting on the intermediate period rotation having large load moment are lessened. |
