Geared continuous hinge

[1] They are often used in schools, hospitals, hotels, offices, airports, stadiums, storefronts and many other commercial and industrial buildings.

They are generally made from extruded architectural aluminum and most are anodized to resist corrosion (common colors include black, bronze and clear).

In 1963 Austin Baer, an MIT-trained engineer, earned a patent for his design of hinge leaves with intermeshed gears.

With the sale, and with other companies beginning to manufacture geared continuous hinges, the market soon went from regional to national.

[3] In 2005, a geared continuous hinge surpassed 25 million open/close cycles in the ANSI (American National Standards Institute) Physical Endurance Swing Test at Architectural Testing, Inc. in St. Paul, Minn.[4] Today, every major U.S. commercial hardware manufacturer now offers a line of geared continuous hinges.