Document binder has flexible prongs joined together to form a ring binder which allow sheets to be taken from within the file without removing the covering papers

摘要

The binder, to file perforated document sheets, has at least four flexible prongs (5,6) mounted in pairs at a base plate (4). One prong can be linked to its paired prong, to form a ring binding through the sheet perforation. Spring clamps (9) are at the base plate for the prongs. The base plate has holes (10), for standard perforation intervals.