Rotary Dial - History

History

From as early as 1836, there were various suggestions and inventions of dials for sending telegraph signals. After the first commercial telephone exchange was installed in 1878, the need for an automated, user-controlled method of directing a telephone call became apparent. The rotary dial was invented by Almon Brown Strowger in 1891. There were numerous competing inventions, and 26 patents of dials, push-buttons, and similar mechanisms for signalling which telephone subscriber was wanted by a caller were issued prior to 1891. Most inventions involved costly, intricate mechanisms and required the user to perform complex manipulations.

The first commercial installation of a Telephone Dial accompanied the first commercial installation of a 99-line automatic telephone exchange in La Porte, Indiana in 1892, which was based on the 1891 Strowger-patent designs. The original dial designs were rather cumbersome and development continued during the 1890s and early 1900s hand in hand with the switching technology. In the 1950s, plastic dials supplanted metal ones in most new telephone designs.

Despite their obsolescence, rotary phones occasionally find special uses. For instance, the anti-drug Fairlawn Coalition of the Anacostia section of Washington, D.C. persuaded the phone company to reinstall rotary-dial pay phones in the 1980s to discourage loitering by drug purchasers, since the dials could not be used to call dealers' pagers.