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Vacuum electric tube

US 1,850,809 A · Inventors: YEOMAN ROBINSON ERNEST

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Listed from its USPTO record in Patent Yard's full-term archive. Its claims, description and drawings are in the USPTO PDF and on Google Patents, and the Claude kit works from them.

Why it's free to use

  • Granted March 22, 1932. A patent granted before 1976 lasted at most 17 years from grant, so its term ended by March 22, 1949.
  • We check US rights only. Old patents can still inspire new ones: improvements may be patentable.
FiledMay 24, 1924
GrantedMarch 22, 1932
Term endedMarch 22, 1949
Application number—
Classification (CPC)H01J9/042
Length3 pages

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