Patent attributes
A ring binder mechanism has a resilient polymeric housing. The housing has a central portion and lateral sides extending downwardly along either side of the central portion. A metal ring support is supported between the lateral sides for movement relative to the housing. Each of a plurality of rings includes a first ring member mounted on the ring support for movement therewith to open and close the rings. The housing applies a spring force biasing the ring support toward the open position when the first ring member is proximate its open position and biasing the ring support to the closed position when the first ring member is proximate its closed position. The housing spring force is the only spring force applied to the ring support that moves the ring support.