Patent attributes
A ring binder mechanism for retaining loose-leaf pages has a housing and a pair of hinge plates supported by the housing for pivoting motion relative to the housing. Mounted on each of the hinge plates are ring members which cooperate to form rings for holding the loose-leaf pages. Pivoting motion of the hinge plates causes the ring members to move between a closed position wherein the two ring members form a substantially continuous, closed loop, and an open position wherein the two ring members form a discontinuous, open loop. A lever is moveable relative to the housing for controlling the pivoting motion of the hinge plates. The lever has a locking position for locking the first and second hinge plates in the closed position. A biasing member engages and biases the lever toward the locking position.
