When does the patent US4984987 expire?

Does the CE Approved CPR and AED Training device infringe this patent?


1 Answer 1


The original filing date is November 9, 1989. A Utility patent is valid for a term of 20 years, which means this patent expired on November 9, 2009 and is no longer valid. The link you posted to does not infringe on this particular patent, but it might be infringing on other patents.

Edit: Eric pointed out that this patent was pre-1995 and there for only valid for a period of 17 years from the issue date.

  • 2
    This patent is from before 1995 which means it expires 17 years from its issue date. Still expired.
    – Eric S
    Commented Jan 4, 2017 at 18:05
  • @EricShain Thank you for the clarification. Commented Jan 8, 2017 at 0:05
  • @JRoibal it would be best if you edited your answer to be fully correct as comments aren't forever.
    – Eric S
    Commented Jan 8, 2017 at 23:30
  • @EricShain thank you for the clarification! I noticed you edited the post to read "from the issue date", so this is the date when the patent is granted, correct? If I understand correctly, the current 20 year term issues from the date when the first priority date. Did this change during the 1995 transition, or am I mis understanding something? Thanks in advance. Commented Jan 13, 2017 at 15:58
  • Your understanding is now correct. Before a particular date in 1995 it was 17 years from issue. After that 20 years from issue.
    – Eric S
    Commented Jan 13, 2017 at 16:28

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