Film cassette

Abstract

Abstract A film cassette is disclosed wherein a spool is rotatable within the cassette shell, a convoluted film roll is wound on the spool, and a pair of flanges are rotatable with the spool. The flanges have respective disks overlying opposite sides of the film roll and respective annular lips circumferentially extending from the disks to radially confine an outermost convolution of the film roll to prevent the outermost convolution from clock-springing against an interior wall of the cassette shell. Each of the annular lips includes an annular constraining section positioned relatively remote from one of the disks and a predetermined radial distance from the spool to enable a lip to contact the outermost convolution of the film roll at a limited location remote from a disk, to radially confine the outermost convolution, and it includes an annular relief section extending from the disk to the constraining section and positioned a predetermined radial distance from the spool, greater than the first-mentioned distance, to enable a lip to avoid contacting the outermost convolution substantially between the disk and the constraining section. This arrangement provides an essentially radial contact between the annular lips and the outermost convolution, thereby preventing any clock-springing of the film roll from generating an axial force against the flanges of the spool.

Inventors

• 👤 Jeffrey C. Robertson

Bibliographic Details