Film cassette wind-on latch - has perforation and tongue on film to engage at entry to take=up chamber after last exposure

摘要

A film cassette and film are designed so that the end foil cannot completely be wound into the take-up chamber. The end of the film (6) has a perforation (12) and associated tongue (16) so that, when wound on, the tongue catches the lip (5) of the take-up chamber (2). By bending over the tongue exerts pressure on the film to latch onto a stop (10, 11) and prevents the final end of film (6) and the following protection paper (7) leader disappearing into the take-up chamber.