Ring opening and closing bar and binding apparatus using the same

摘要

A rectangular opening/closing bar is formed, which is inserted in the curl ring of the ring binder to bind papers. The tip end of the opening/closing bar 28A is provided with an instruction portion 28a to raise and open ring pieces in turn while inserting the opening/closing bar 28A. Further, the opening/closing bar may have swollen portions on both ends of the opening/closing bar 28A to enable the bar slide smoothly in the curl ring. And it may be provided with a guide plate 28D perpendicular to the side wall 28b of the opening/closing bar 28A of the swollen portions side. In order to enhance the workability of the opening/closing bar, it may be preferable to use an auxiliary device for positioning the ring binder.