Ring binder

Ring binders (loose leaf binders, looseleaf binders, or sometimes called files in Britain) are large folders that contain file folders or hole punched papers. These are held in the binder by circular or D-shaped retainers, onto which the contents are threaded. The rings are usually spring-loaded, but can also be secured by lever arch mechanisms or other securing systems. The binders themselves are typically made from plastic with metal rings. Early designs were patented during the early 1890s to the early 1900s.

History

German Friedrich Soennecken invented ring binders in 1886 in Bonn, Germany. He also registered a patent on November 14, 1886, for his Papierlocher für Sammelmappen ("paper hole maker for folders", or hole punch). German Louis Leitz, founder of Leitz later made some important changes in development of ring binders in Stuttgart-Feuerbach. Leitz introduced the "finger hole" on the side of the binder to aid removal from crowded shelves.

The ISO standard two holes are 80 millimetres (3.1 in) apart, according to ISO 838. The four-hole version has no ISO standard. The distances between holes are 80 millimetres (3.1 in) (3×8).