Photographic film cassette having a locking spool

摘要

A photographic film cassette has photographic film wound on a spool and rotatably contained in a cassette shell. A leader of the photographic film is advanced outward from a passage mouth when the spool is rotated in the unwinding direction. The spool has a toothed wheel. A spring plate is provided inside the cassette shell. The spool is stopped by the spring plate from rotating. The spool is allowed to rotate when a torque of at least 50 gfxcm is applied to the spool. While a camera is loaded with the novel cassette, the spring plate is displaced to make the spool free from the toothed wheel to rotate. In another preferred embodiment, the spool is provided with a biased stopper, which is pressed with friction against the inside of the cassette shell. This friction stops the spool from freely rotating.