| 摘要 |
A film cartridge having a housing, a spool rotatable in film winding and unwinding directions within the housing, a film roll wound onto the spool and having a clock-springing tendency to urge the spool in the film unwinding direction, and an anti-backup pawl and cooperating ratchet teeth arranged on the housing and the spool for the pawl to engage any one of the ratchet teeth to prevent the clock-springing tendency of the film roll from urging the spool in the film unwinding direction and for the pawl to be disengaged from successive ones of the ratchet teeth when the spool is rotated in the film winding direction to wind the film roll onto the spool, is characterized in: that the housing includes a sheath that partially covers the film roll, that has a film passage opening, and that is resilient to permit the sheath to be flexed; and the pawl and the ratchet teeth are rigid and one of them is arranged on the sheath to allow the pawl and successive ones of the ratchet teeth to flex the sheath in order to disengage from one another when the spool is rotated in the film unwinding direction, whereby a filmstrip that forms the film roll can be pulled off the spool and through the film passage opening.
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