Film cassette with spool lock and light-shielding door

A film cassette comprising light-shielding means for preventing ambient light from entering the cassette interior, a film spool supported for rotation in film unwinding and film winding directions, and locking means supported for pivotal movement into engagement with said spool to secure the spool and out of engagement with the spool to release the spool, is characterized in that:

• said light-shielding means is supported for closing movement to prevent ambient light from entering the cassette interior and for opening movement, and includes cam means for pivotally moving said locking means into engagement with said spool responsive to closing movement of the light-shielding means and for holding the locking means engaged with the spool;
• and
• said locking means includes first resilient means for being temporarily deformed should the locking means be blocked from being pivotally moved by said cam means to engage said spool and said light-shielding means is forcibly closed or should the locking means be held engaged with the spool and the spool is forcibly rotated in the film unwinding and winding directions, and second resilient means for being temporarily deformed independent of said first resilient means should the locking means be held engaged with the spool and the spool is forcibly rotated in the film unwinding and winding directions, whereby the light-shielding means is permitted to be closed even though the locking means is obstructed and the spool is permitted to be rotated even though the locking means is engaging the spool.