In reference to the patent: US1899496

I have a copy of a patent given to my great grandmother for the automatic gate for railways. The patent was given on August 28, 1928. It was awarded to her but my great grandfather actually invented it. His name was John Kovacs. The patent was put in her name because he spoke little English.

The renderings featured in the patent filed in 1933 are the exact renderings of my great grandfathers. How can a new patent be awarded in 1933 for the same invention? I believe the patent number is US1682573.

1 Answer 1


How can US1899496 exist if US1682573 preceded it and they solve the same problem? Although the figures do seem similar, the mechanisms and circuits are different in details. It is very common for there to be multiple patents related to solving the same problem. It is important to look specifically at the claims to determine the differences. In this case the claims for US1682573 relate to a mechanism to raise and lower the gates where as US1899496 relates to a circuit to control the gate opening. Thus they are different inventions.

In any case, I'd like to point out that both of these patents expired many years ago so there is no infringement now possible.

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