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Multiple switch-board for telephone-exchanges

US 252,576 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 January 17, 1882. A patent granted before 1976 lasted at most 17 years from grant, so its term ended by January 17, 1899.
  • We check US rights only. Old patents can still inspire new ones: improvements may be patentable.
FiledJanuary 7, 1881
GrantedJanuary 17, 1882
Term endedJanuary 17, 1899
Application number—
Classification (CPC)H04M5/06
Length3 pages

Timeline

Timeline From USPTO dates

188218841886188818901892189418961898Application filedJan 7, 1881Patent grantedJan 17, 1882Term endedJan 17, 1899

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