In reference to the patent: US925691

Dear Sirs,

The gentleman referenced as the inventor, and holder of this patent, is my Great Grandfather - Glyndon Abraham Freer. I have a copy of the original patent provided to him by the U.S. Patent office. Does this document have any worth? Since it's something connected to my heritage, it's priceless.

thank you

H. Robert Freer Milwaukee, WI 414-426-2652

2 Answers 2


Does this document have any worth?

The patent itself has expired and cannot be enforced against anyone who might otherwise be an infringer. If there have been an unbroken string of "follow-on" applications ("Continuations" and "Continuation-in-Part") there is a very slight chance that some patent rights may yet exist (although if I think about it, probably not since the changeover to "twenty-year term from filing the application" happened more than 20 years ago – although your grandfather's patent line might be "grandfathered" in :-) ). Essentially, the invention has entered the public domain and is free for anyone to use. That was the bargain your grandfather struck with the government – in order to obtain a limited term commercial monopoly from the government, he agreed to disclose the invention to the public so that anyone may make and use the invention (only subject to his patent rights while his patent term existed, and thereafter for free forever).

There may also be some value as prior-art -- namely to help invalidate someone else's patent if they are asserting that they have existing patent rights covering the same invention (or an obvious modification). But again, as a public domain document, easily obtainable by a search engine, the document itself may not have any intrinsic monetary value.

Still, I am happy for your family's pride.


It might have some value to any of the following:

  • a farmer's association, especially if they are potato growers
  • if it was ever manufactured, the company that manufactured it (they may show it off in their archives or head office)
  • any museum of history, especially if they have a farming/agriculture section

Of course, you say it is priceless, presumably you are referring to it being priceless to yourself, so you may not want to sell it, but you can "loan" it to one of the above entities for a period of time.

  • Since he has a copy and not the original, I'm not sure there is collector value.
    – Eric S
    Commented Mar 31, 2017 at 23:17

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