Ring Binder Mechanism

A ring mechanism for holding loose-leaf pages, the ring mechanism comprising:

• a housing having a longitudinal axis;
• a pair of hinge plates supported within the housing for pivoting movement relative to the housing between a first hinge plate position corresponding to a closed configuration of the mechanism and a second hinge plate position corresponding to an open configuration of the mechanism, each of said hinge plates supporting thereon two or more ring members, wherein each of the ring members on one of said hinge plates engages a corresponding ring member on the other of said hinge plates to form a continuous ring when the hinge plates are in said first hinge plate position and the mechanism is in said closed configuration;
• and
• a lever pivotally connected to said housing and arranged to pivot about an axis oriented perpendicularly to the longitudinal axis of the housing and extending upwardly relative to the housing, the lever having a camming surface which engages at least one of said hinge plates to drive the hinge plates from one of said first and second hinge plate positions to the other of said first and second hinge plate positions when the lever pivots from a first lever position to a second lever position.