Film cassette

An improved film cassette wherein (a) a spool is rotatable in an unwinding direction within a cassette shell having a film passage slit and (b) a convoluted film roll wound on said spool tends to expand radially in response to initial rotation of the spool in the unwinding direction, and wherein the improvement comprises:

• rotatable constraining means for radially confining an outermost convolution of said film roll to prevent the film roll from radially expanding substantially into contact with said cassette shell, said constraining means being coaxially arranged with respect to said spool to permit independent rotation of the spool at least initially in the unwinding direction to tend to expand said film roll radially to ensure a non-slipping relation between said outermost convolution and said constraining means and thereby enable further rotation of said spool in the unwinding direction to similarly rotate the constraining means;
• release means for freeing successive sections of said outermost convolution from the radial confinement of said constraining means as corresponding portions of the constraining means are rotated past said release means;
• and
• guide means for directing freed sections of said outermost convolution to said film passage slit.

An improved film cassette wherein (a) a spool is rotatable within a cassette shell having a film passage slit and (b) a convoluted film roll having a leading end is wound on said spool, and wherein the improvement comprises:

• rotatable constraining means for substantially continuously confining an outermost convolution of said film roll including its leading end to prevent the film roll completely from contacting said cassette shell, said constraining means capable of being flexed to free said outermost convolution including said leading end from the confinement of the constraining means;
• rigid fixed release means for directly flexing successive portions of said constraining means to free corresponding sections of said outermost convolution from the confinement of the constraining means as those portions of said constraining means are rotated past said release means;
• and
• guide means for directing freed sections of said outermost convolution to said film passage slit.

An improved film cassette wherein (a) a spool is rotatable within a cassette shell having a film passage slit and (b) a convoluted film roll is wound on said spool, and wherein the improvement comprises:

• rotatable constraining means for radially confining an outermost convolution of said film roll to prevent the film roll from contacting said cassette shell, said constraining means capable of being flexed to free said outermost convolution from the radial confinement of the constraining means;
• rigid fixed release means disposed in continuous contact with said constraining means for directly flexing successive portions of the constraining means to free corresponding sections of said outermost convolution from the radial confinement of said constraining means as those portions of said constraining means are rotated past said release means;
• and
• guide means for directing freed sections of said outermost convolution to said film passage slit.

An improved film cassette wherein (a) a spool is rotatable in an unwinding direction within a cassette shell having a film passage slit and (b) a convoluted film roll wound on said spool tends to expand radially in response to initial rotation of said spool in the unwinding direction, and wherein the improvement comprises:

• a pair of rotatable disks coaxially spaced along said spool and having respective central holes through which the spool extends to permit rotation of said spool relative to said disks, said disks including respective continuous circumferential lips which radially confine an outermost convolution of said film roll both to prevent the film roll from radially expanding substantially into contact with said cassette shell and to ensure a non-slipping relation with said outermost convolution, when the film roll tends to expand radially in response to initial rotation of said spool in the unwinding direction, to thereby enable further rotation of the spool in the same direction to similarly rotate the disks;
• release means for freeing successive sections of said outermost convolution from the radial confinement of said circumferential lips as corresponding portions of the lips are rotated past said release means;
• and
• guide means for directing freed sections of said outermost convolution to said film passage slit.