Patently-O TidBits — King of the Submarine.

Bill Friedman filed his patent application on October 23, 1936 on a new cryptographic system. The patent finally issued some 64 years later as U.S. Patent No. 6,130,946. Can you find any currently viable patent with an earlier filing date?


* This tidbit came from the great discussion ongoing at the Patent Information User’s Group about record-holding patents (longest pending, most claims, etc.). 

UPDATE: A reader found Patent No. 6,097812 by the same inventor.  It is still viable, but the filing date was July 25, 1933!

9 thoughts on “Patently-O TidBits — King of the Submarine.

  1. 8

    But is it valid? This looks a lot like an Enigma machine, which was in use more than a year before applicant filed. I can’t recall if the 102b criterion back then was one year or two, but “The Enigma was used commercially from the early 1920s on, and was also adopted by the military and governmental services of a number of nations — most famously by Nazi Germany before and during World War II.” See Wikipedia entry:
    link to

  2. 6

    Dennis, I think the method of metaphoric submerging and resurfacing has to be considered when deciding to label a patent a submarine. If this patent was the subject of a secrecy order then it was not the inventor’s or assignee intent to prolong or delay the issue of the patent for their gain. Considering this is cryptography patent filed prewar with the US Government as assignee suggests this was subject to a secrecy order. I recall another WWII-era patent which issued around 2001 in the field of radar that did have its issuance held up by a secrecy order.

  3. 4

    I believe that it would indeed have been subject to a secrecy order, based on subject matter and date.

    Given the current administration’s attitude towards secrecy, particularly the recent revelation that they’ve been reclassifying docs from the National Archives, we shouldn’t expect any more patents like this to issue for a few years.

  4. 2

    U.S. Patent 6,097,812 filed 7/25/1933 issued 8/01/2000

    Plus there are a bunch of patents published in the 1990s with misprints indicating filing dates in the first decade of the 20th century (1905, etc.)

  5. 1

    This one appears quite old, but it could just be a wedgie in the USPTO database, given the dates of the cited prior art: 5,570,648

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