Patent ID: 8899864

Claim:
A ring binder for use in holding loose-leaf pages, the ring binder comprising: an elongate body; rings for retaining loose-leaf pages, each ring including first and second ring members extending from and supported by the elongate body, the first and second ring members being moveable relative to one another between a closed position in which the first and second ring members together form a substantially continuous, closed loop for allowing loose leaf pages retained by the ring to be moved along the ring from one ring member to the other and an open position in which the first and second ring members form a discontinuous, open loop for adding or removing loose-leaf pages from the ring, the ring members each having a substantially circular cross sectional shape along a majority of their length; and a retaining system operable to selectively and releasably hold the first and second ring members in the closed position, the retaining system comprising first and second interlocking formations adjacent the ends of the first and second ring members, respectively, that are operable to engage one another to limit relative movement between the ends of the ring members away from the closed position, wherein the rings and body are formed together as a one-piece unitary structure made of a moldable polymeric material, the first and second ring members being in an undeformed state in the open position and moveable from the open position to the closed position by resiliently deforming the first and second ring members, the first and second ring members being biased by internal elastic restoration forces when they are in the closed position to move toward the open position, the first and second ring members having ends the straight line projections of which intersect at an angle of at least about 75 degrees in the undeformed position.