sam dupont
Well-Known Member
They make pocket cards and charts that show date ranges of patent numbers. Somebody gave me a pocket card and I didn't really want to carry that thing around as it's not something needed often, so I studied it.
I saw a pattern in the numbers and dates. To date a patent number, multiply the first two numbers times by 2. It's high or low by a few years, but it gets into the ballpark without having to carry the card.
I saw a pattern in the numbers and dates. To date a patent number, multiply the first two numbers times by 2. It's high or low by a few years, but it gets into the ballpark without having to carry the card.
