Alexander Milburn Co. v. Davis-Bournonville Co.
270 U.S. 390 (1926)

  • Clifford invented a new type of welding torch. He filed a patent application that completely described the new torch, but in the claims section, it didn't claim one specific improvement that had been described in the description section.
    • Clifford's patent disclosed but didn't claim.
  • A little later, Whitford independently came up with the same improvement. He filed a patent on the improvement. Both Clifford and Whitford's patents were granted.
  • Davis-Bournonville owned Whitford's patent. They sued Milburn (who was manufacturing a similar welding torch) for infringement.
    • Milburn countersued and claimed that Whitford's patent was invalid.
    • Milburn argued that Clifford invented the improvement first, so Whitford could not rightfully patent it.
  • The Trial Court found for Davis-Bournonville. Milburn appealed.
    • The Trial Court found that Clifford might have added this claim to his application, but he didn't, so he was not a prior inventor.
    • The Court found that (under what is now 35 U.S.C. 102(g)) if a second filer can show conception and reduction to practice before the first filer filed, then the second filer gets the patent. The Court found without a claim, the thing described is not reduced to practice.
  • The Appellate Court affirmed. Milburn appealed.
  • The US Supreme Court reversed.
    • The US Supreme Court found that Clifford's description in his patent application satisfied the requirement of reduction to practice, even though Clifford had not made a claim on that specific improvement.
      • " A description that would bar a patent if printed in a periodical or in an issued patent is equally effective in an application so far as reduction to practice goes."
    • The Court found that since there was evidence Clifford had both conceived of and reduced to practice prior to Whitford's filing, Whitford's patent was invalid.
    • The Court based their reasoning on the idea that if the USPTO was 'divinely efficient' they would grant patents on the same day that they were filed. Any delay between filing and grant is the fault of the inefficient USPTO and inventors should not be punished for that.
  • This was an unusual ruling because it basically said that patent applications (which are generally secret until the patent is issued) count as the prior art despite the fact that they aren't available in the public domain.
    • On the other hand, had this case gone the other way, Clifford would have been infringing on Whitford's patent. Would that be fair to Clifford?
  • The ruling in this case was later codified in 35 U.S.C. 102(e).
    • Disclosures that are not claimed in a patent application are still considered to be in the public domain and are prior art.