3 ms·

AFAIK US patents expire 20 years after filing, which means that a number of them will soon be expired. http://www.google.com/patents/US5579517 http://www.googl

• pwg 12y ago
  5579517 is pre-gatt, so it is 17 years from date of grant, which for it is Nov 26, 1996 + 17 years => Nov 26, 2013 - so already expired. 5758352 is post-gatt, so it is 20 years from earliest priority date, the earliest priority date is Apr. 1, 1993 + 20 years = Apr. 1, 2013 - so also already expired (unless it has any term extension). 6286013 is also post-gatt, also with a priority date of Apr. 1, 1993 + 20 years = Apr. 1, 2013 - so also already expired (unless it has any term extension). 5745902 is pre-gatt, it patented Apr. 28, 1998 and gets 17 years from that date, so Apr. 28, 1998 + 17 years => Apr. 28, 2015 - it expires in about six months.