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I had designed a similar invention like the Patent US5,934,963 but have found this patent was already in force.

It seems to have lapsed and been re-instated several times...

Can you determine the current status?

marked as duplicate by Robert Cartaino Oct 2 '14 at 14:34

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.


No, the patent has not expired. It was filed for in 1998 so it will probably be active through most of 2018.

Google Patents shows that it expired September 27, 2011 due to failure to pay a maintenance fee, but that a petition for late payment was granted.

Your best bet is likely to look into differentiating your invention, or licensing that patent.

  • @user11607 Glad to help. Please mark this answer as accepted by clicking the checkmark if it helped you. – Matthew Haugen Oct 1 '14 at 19:19

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