Wagner gear

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Mechanism (Wagner gear) of a type lever typewriter.
All levers are rotatably mounted in the machine frame (mutual connection with rotary slide joint , pin in fork).
A: key lever; B: intermediate lever; C: type lever;
Rest position: blue; Type stop: red

The Wagner gearbox is part of a typewriter that was invented by Franz Xaver Wagner from Heimbach bei Neuwied, who emigrated to the USA , together with his son Herman in 1890 and which was patented to him in 1893.

It transfers the movement of the key via an intermediate lever to the associated type lever , which swings upwards by about 90 ° from the horizontal ( rocker arm ) and hits the type on the platen from the front. Until the invention of the Wagner gear, the types hit almost all typewriters from below or from above, so that the writer could not read what was just written and could not immediately recognize and correct errors. The Wagner gear made it possible to build a typewriter with a relatively light keystroke and immediately visible writing.

Wagner also introduced the semi-circular arrangement of the type lever mechanisms. These each lie in a radial section plane through a cylinder. The attachment point of the type lever is located in the cylinder axis. The frame part with the bearings of the levers is what will later be called the segment . In addition, Wagner used in his typewriter manufactured by Wagner Typewriter Co., New York , the arrangement of the letters on the keypad that was established in 1888 at the first typist's congress in Toronto and is still valid today. In 1896, John T. Underwood acquired Wagner's factory and patents.

The Underwood typewriters became the standard lever type typewriter; The other typewriters gradually adopted the basic principle of the type lever mechanism invented by Wagner. In 1906, the Wagner gearbox, in which button, intermediate and type levers with rotary-slide joints directly interlocked, was improved by the American Edward B. Hess . Hess inserted a pull wire between the key and intermediate lever as well as between the intermediate and type lever, thereby ensuring that the type lever has the greatest rotational acceleration at the moment of the type impact, although the key press and key movement remain the same. With this technical solution, catching of the type lever was largely ruled out, even when writing very quickly.

Individual evidence

  1. ↑ Peter Tschudin: Hopping letters - Brief history of the typewriters , Communication No. 38 of the Basler Papiermühle , Basel, 1983, page 15
  2. ↑ Sketch of a Wagner gearbox [1]
  3. ↑ Werner von Eye: Brief History of the Typewriter and Typewriting , H. Apitz Verlagsbuchhandlung, Berlin 1941, p. 18
  4. ↑ a b Werner von Eye: Taste - Lever - Norm , Georg Achterberg, Verlag für Berufsbildung, Berlin 1958, pp. 10-12.
  5. ↑ Werner von Eye: Brief History of the Typewriter and Typewriter , H. Apitz Verlagbuchhandlung, Berlin 1941, pp. 18/19
  6. ↑ Sketch of a pull wire gear [2]