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U.S. Patent 3,305,289
Elmer Fridrich's Machine for
Making Short-arc Lamps

Image of Elmer Fridrich's machine for making short-arc lamps patent, 1967

This patent, granted on 21 February 1967, shows a method of manufacturing short-arc discharge lamps. 

Elmer Fridrich, co-inventor of the tungsten halogen lamp, began his career at General Electric as a machinist working the night-shift. After he began inventing lamps for GE, his skills as a machinist allowed him to anticipate the type of problems that would arise when products moved from the lab to the production line. Several of his patents describe production equipment like the one seen above. 

Short-arc lamps may be recognized by most people as the strange, bluish headlight now being adopted in automotive designs. A difficulty with making such lamps is quickly extracting the air from inside the small bulb, and installing a gas such as xenon. The machine described above, not only takes care of the atmosphere inside the lamps, but also installs the electrodes and seals the ends. 

In 1996, Fridrich donated the original patent document to the National Museum of American History, along with other historical materials including a large collection of experimental lamps.

The image above has been enhanced electronically.


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