Is patent US6676109 for a rotary valve in favour of Kitz Corporation a design patent or a utility patent? What is it's expiry date?
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.