Film cassette

Abstract

A film cassette has a casing, and a take-up core is mounted in the casing for rotation in opposite directions. An arresting element is connected to the core for joint rotation therewith and is biased toward a position in which it moves in a path during such rotation. A plurality of detent members is provided on the casing so as to extend into said path when the core is assembled with the casing, and each of them has a detent surface against which the arresting element abuts when it is attempted to rotate the core in one direction, and a guide surface which deflects the arresting element out of said path when the core rotates in the opposite direction. The core may include a stub on which the arresting element is provided, and an annular portion surrounding the stub. The arresting element may have a support portion connected to the stub, and an arresting portion which cooperates with the detent element. Two protective projections may surround the support portion in circumferential direction of the core and with spacing therefrom and at least one shearing projection may be provided at one of the protective projections which shears the support portion from the arresting portion when a force exerted upon the arresting portion by the detent element during the attempt to rotate the core in said one direction exceeds a predetermined magnitude.

Dependencies are inferred from the claim text.