1963 — Austin Baer earns patent for inventing the geared continuous hinge while working for McKinney Products Co. Earns a second patent in 1968. Soon after, leaves to start Roton.

1985 — Baer’s patents expire.

1989 — Baer sells Roton to Hager Companies. SELECT develops its geared continuous hinge.

1991 — Pemko Manufacturing Co. (a division of Assa Abloy) develops a geared continuous hinge. Soon after, Ives (a division of Ingersoll-Rand Security Technologies) offers geared continuous hinges.

2002 — SELECT begins endurance test (hinge eventually completes 25 million cycles)

2004 — SELECT earns certification from State Department

2005 — SELECT offers industry’s only Continuous Warranty™

The History of the Geared Continuous Hinge

Geared continuous hinge is born

Over its 40-year history, the aluminum geared continuous hinge has become the preferred hinge for high-traffic, high-abuse commercial entrances. Today, every major U.S. commercial hardware manufacturer now offers a line of geared continuous hinges.

It began in 1963, when Austin Baer, an MIT-trained engineer working for McKinney Products Co., earned a patent for his design of hinge leaves with intermeshed gears. In 1968, he earned a second patent for adding thrust bearings to the original design. All geared hinges today are based on this design, which distributes the door’s weight over the entire door length rather than concentrated on two or three spots as with butt or pivot hinges, which quickly wear out on high-traffic doors. And the gears allowed fluid movement as the door opened and closed.

Shortly thereafter, Baer left McKinney to start his own company, Roton Corp., to produce and sell his hinges in the northeastern U.S., Michigan and Illinois. Baer named the company Roton after a measure in physics of rotational energy in fluid, based on the hinge’s rotational operating movement.

Manufacturing expands

Baer’s patent expired in 1985. Contemplating retirement, he opened negotiations with Stanley Works (makers of the famous Stanley line of tools), but eventually sold Roton to Hager Companies in 1989. With the sale, the geared continuous hinge market went from regional to national, from niche to mainstream. The geared continuous hinge had earned a respected place in commercial hardware.

At this time, Hager became the only geared hinge producer. Hager had its own sales representatives who replaced Roton’s. This move impacted Special-Lite, a manufacturer of heavy-duty entrance systems that had not only purchased hinges from Roton, but also had shared sales representatives. With its sales representatives now no longer representing a geared hinge, Special-Lite decided to start its own hinge company. In 1989 it formed SELECT Products Limited. SELECT, utilizing Roton’s former sales representatives, began producing geared continuous hinges while refining and improving the design.

Seeing a good opportunity, other companies also entered the market. In 1991, Pemko Manufacturing Co. (now a division of Assa Abloy) came out with its version of a geared continuous hinge, using thinner aluminum in the leaves and fewer bearings than competitors. More recently, Ives (a division of Ingersoll-Rand Security Technologies) also began offering a geared continuous hinge imported from Asia.

Over the years other companies, including Markar Architectural Products (a division of Assa Abloy) and Stanley Works, recognized the quality of SELECT’s geared continuous hinges and sold SELECT hinges under their own brands. After a Hager lawsuit stopped Stanley from selling SELECT hinges, Stanley returned to the continuous hinge market in 2000 by selling imported hinges.

SELECT takes geared continuous hinges to new performance levels

In 2002, SELECT Products began endurance testing one of its hinges at Architectural Testing, Inc. in St. Paul, Minn. The Physical Endurance Swing Test ran the hinge through 25 million open/close cycles without fail, simulating more than 50 years of use on a high-traffic door. That’s 10 times beyond BHMA Grade 1 cycle count. In 2004, a SELECT hinge earned certification from the U.S. Department of State for use in overseas embassies by surviving brutal attacks with hand tools and rifle fire. The result of these tests led SELECT in 2005 to offer the industry’s only Continuous Warranty™, a warranty that never expires.


Others claim their hinges are the best. We prove it. Our geared continuous hinges have resisted more brutal testing than any. Read more.

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