Patent ID: 6089486
Filing Date: 2000-07-18
Classification: G03B

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