My U.S. Pat. No. 4,002,309 issued Jan. 11, 1977, exemplifies movie film bobbins having a relatively rotatable floating hub for winding the film and which meet interfitting storage panels at relatively rotatable bearing surfaces so that the film layers are retained between the panels as they are wound about the hub.
Because of the relative rotation of the hub and panels and the particular interfitting dimensions involved where the panels fit tightly in bearing surfaces on the hub, there is a tendency for the parts to wear to enough of an extent that particular care must be given to assembly tolerances and the kinds of materials used.
USPTO Backgrounds
USPTO Backgrounds