Egbert v. Lippmann
104 U.S. 333 (1881)

  • Barnes heard his wife and her friend complaining that their corsets kept breaking. Barnes invented a new type of doo-dad that would make the corsets more sturdy. He gave one to his wife who used it for over ten years.
    • Barnes also brought one of his friends over one day to show them how the doo-dad worked.
  • Eleven years after originally making the doo-dad, Barnes applied for and received a patent on it. It became very popular.
    • Barnes died and his wife inherited the patent.
  • Later, a competitor, Lippmann began manufacturing corsets with the same doo-dad. Barnes' wife sued for infringement.
    • FYI, Mrs. Barnes remarried which is why the name on the case is Egbert.
  • The US Supreme Court found the patent to be invalid.
    • The Court looked to the patent law (now 35 U.S.C. 102(b)), which said that you could not patent something that was in public use, with the consent and allowance of the inventor, for more than two years prior to his application.
      • FYI, the current standard in 102(b) is one year, but back then it was two years.
    • The Court found that even if one other person has use and knowledge of the invention that counts as public use.
      • There was nothing stopping Mrs. Barnes from showing the doo-dads to other people, or selling them. So for all practical purposes the invention was potentially available to the public.
    • The Court noted that if there had been a confidentially agreement, then it would not have been a public use.
  • In a dissent, it was argued that this was not a public use, but instead a 'private use with consent'. Considering that this invention was in Mrs. Barnes' underwear, and she probably didn't go around showing her undies to people, how could it be a public use?
    • The dissent argued that confidentially was implied by the nature of the patent.
  • The Public Use Exception is important because the US has a "first to invent" patent system. If the exception didn't exist, then a person could invent something, sell it all over the place, and then only apply for a patent once a competitor started copying it. Since no competitors would copy the product knowing that the inventor could patent it at any time, the inventor's monopoly would be indefinitely extended.
    • In addition, other inventors who might independently invent something need assurance that there isn't someone out there who has already invented it and is just sitting on the invention waiting to sue them.