Is patent US 6,676,109 for a rotary valve in favor of Kitz Corporation a design patent or a utility patent?
What is the expiration date of the patent?
Design patents are designated with a "D" in front of them, like "D432100. The standard 7 digit patent number is a utility patent.
You can go to: https://ramps.uspto.gov/eram/patentMaintFees.do to check out the status of an application's maintenance fees.
This patent (6676109) is based off of Application 10/412,585, and appears currently paid up and in force. If the next fee is paid in 2015, it will stay in force until 04/14/2023.
If you look in the first paragraph of the description of the Utility Patent US 6,676,109, you will find:
This is also clearly noted on the first page of the patent:
The filing date to start counting from is therefore May 22, 2001, which gives an expiration date of May 22, 2021.
Also of note is:
Which, since it is 0 days, does not affect the expiration date.
Finally, check the Legal Events to ensure the maintenance fees have been paid:
The fees have been paid, so the patent will remain enforceable until at least January 13, 2016. Since Kitz Corporation is typically paying the fees in June, you may want to re-check the Legal Events next month to see if they have paid.