Snap-ring type box file mechanism

A ring binder (10) is disclosed as comprising a substantially rigid casing (12) supporting a pair of plates to which at least two pairs of ring members (16) are mounted, the pair of plates being pivotally movable between a first position in which the pairs of ring members are closed and locked, and a second position in which the pairs of ring members (16) are open and unlocked, and when force is applied on at least one pair of ring members (16), the ring binder (10) is unlocked and the pair of plates are movable from the first position to the second position in order to open all the pairs of ring members (16), and when force is applied on at least one other pair of ring members (16), the pair of plates are locked against movement from the first position to the second position. <IMAGE>