Patent attributes
A ring binder mechanism that retains loose-leaf pages and has ring members that do not snap together when they close and that easily open and close as pages accumulate. The mechanism includes a housing that supports two hinge plates for loose pivoting motion, moving the ring members apart or together. The mechanism further includes an actuating lever pivotally mounted on the housing. The lever moves a travel bar and locking elements for controllably pivoting the hinge plates, and therefore controllably moving the ring members apart and together. In particular, the locking elements cam the hinge plates to softly close the ring members. When the ring members are apart, the locking elements register with openings in at least one of the hinge plates. When the ring members are together, the locking elements are out of registration with the openings, blocking the hinge plates from pivoting to separate the ring members.