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Musical key control

US 2,452,307 A · Inventors: KOEHL JAMES A

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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 October 26, 1948. A patent granted before 1976 lasted at most 17 years from grant, so its term ended by October 26, 1965.
  • We check US rights only. Old patents can still inspire new ones: improvements may be patentable.
FiledMarch 20, 1946
GrantedOctober 26, 1948
Term endedOctober 26, 1965
Application number—
Classification (CPC)G10H1/0558
Length6 pages

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