Patent ID: 7524128

Claim:
A ring binder mechanism for retaining loose-leaf pages, the mechanism comprising: a housing; a first hinge plate and a second hinge plate, the hinge plates being supported by the housing for pivoting motion relative to the housing; rings for holding the loose-leaf pages, each ring including a first ring member and a second ring member, the first ring member being mounted on the first hinge plate and moveable with the pivoting motion of the first hinge plate relative to the second ring member between a closed position and an open position, in the closed position the two ring members form a substantially continuous, closed loop for allowing loose-leaf pages retained by the rings to be moved along the rings from one ring member to the other, and in the open position the two ring members form a discontinuous, open loop for adding or removing loose-leaf pages from the rings; a lever moveable relative to the housing and arranged for direct contact with at least one of the hinge plates to control the pivoting motion of the hinge plates to both the open and closed positions, the lever having a locking position for locking the first and second hinge plates in the closed position, the lever including at least one arm disposed below at least one of the first and second hinge plates for engaging the hinge plate and moving the hinge plate upward as the lever is moved to move the ring members toward said open position; a biasing member comprising a spring engaged with the lever and biasing the lever toward the locking position a hinge pin connecting the spring and the lever to the housing.