| 摘要 |
A film guide mechanism for use in rolling loop film transport mechanisms minimizes film wear and permits higher film speeds on the order of 30 frames per second. The film is sandwiched in its path of travel between a driven inlet drive sprocket and a shock double capstan, the inlet drive sprocket having a plurality of teeth that mate with perforations along each edge of the film and that also mate with grooves in the shock double capstan that is in turn frictionally driven by the driven inlet drive sprocket. The driven inlet drive sprocket and the shock double capstan are slightly concave in shape to prevent contact between these components and the central emulsion area of the film. A fixed inner guide having a radius in an area adjacent the shock double capstan that matches the radius of the shock double capstan and a spring-loaded shock double capstan slide on which the shock double capstan is mounted provide a variable gap to accommodate any backlash or shock rebound of the film as it passes through the gap prior to capture by a rotor of the film transport mechanism. A selectable stop engages the shock double capstan slide to prevent narrowing of the variable gap beyond a predetermined minimum.
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