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.
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.
Another design for ring binders was invented in 1889 by Andreas Tengwall in Helsingborg, Sweden, and patented in 1890 under the name 'Trio binder', named after a business consortium of Tengwall and two associates. Tengwall's design uses four rings, in two paired sets. The hole placement of Tengwall's Trio binder is still used as a de facto standard for hole punching in Sweden under the name triohålning. These holes are 21 millimetres (0.83 in), 70 millimetres (2.8 in), and 21 millimetres (0.83 in) apart. (In this article, it makes mention that, according to the curator of the Early Office Museum in London, the first patent for ring binders was filed in 1859 for a two-ring binder. A few years later three-ring binders became the standard in the United States; the "D" ring binders did not come on the market there until the 1940s or 1950s.)
William P. Pitt obtained patent no. 778070 on December 20, 1904 for a 3-ring binder that became a standard in the United States. The North American de facto standard spacing is 4.25 inches (108 mm) between holes.
The most common type in Canada and the United States is a three-ring system for letter size pages (8 1⁄2 inches × 11 inches). A standard 8 1⁄2 inch × 11 inch sheet of paper has three holes with spacing of 4 1⁄4 inches (107.95 mm). "Ledger" size binders hold 11-by-17-inch (28 by 43 cm) paper, and may use standard 3-ring spacing or multiple additional rings.
The distance from the punched holes to the nearest edge of the paper is less critical, since small differences do not affect the compatibility of paper and binder. Typical distance from the paper edge to the center of the hole is 0.5 inches (13 mm), and typical diameter of the hole ranges from 0.25 inches (6.4 mm) to 0.31 inches (7.9 mm) in North American usage.
The lever arch system is helpful when wanting to hold large amounts of paper into a small, easy to carry around folder.
Many personal organizers and memorandum books use a six- or seven-hole system, including Filofax, the FranklinCovey, and Day-Timer®. Most systems have the rings on the left side of the papers as one opens the binder, but there are also binders that have the rings (concealed by the binder cover) at the top edge of the paper, reminiscent of a clipboard.
Most binder covers are made of three pieces, in the fashion of a hardback book, but are produced in many styles. Materials vary widely. Some vinyl binders have a clear pocket on the outside for cover pages, and many have pockets in the inner cover for loose papers, business cards, compact discs, etc. There are also zipper binders, which zip the binder up and keep papers from falling out. Some binders are stored in matching slipcases for greater protection; either with one slipcase per each binder, or one slipcase holding several binders.
- "Lever Arch Mechanisms :: RING ALLIANCE". www.ring-alliance.com. Retrieved 2015-11-04.
- "Lever Arch Insert Binders - Aspire Office Products". aspireofficeproducts.com.au. Retrieved 2015-11-04.
- Media related to Ring binders at Wikimedia Commons