There are no earlier related applications, so adding 20 years to the filing date gives 27 March 2021 as the expiry date.

For example, US 6472448 has a filing date of 27 March 2001.

For applications filed on or after 8 June 1995, the expiry date is 20 years from the date of the earliest related application, or where there are no earlier applications, the filing date.

The expiry date is the later date, 20 December 2011. Adding 20 years to the filing date gives 20 December 2011, and adding 17 years to the issue date gives 15 June 2010.

For example, US 5219846 has a filing date of 20 December 1991 and an issue date of 15 June 1993.For applications filed prior to, and still in force or pending on, 8 June 1995, the expiry date is the later of 17 years from the issue date, and 20 years from the filing date.The commonly held view of how to calculate US patent expiry dates is as follows: Why then, is it so difficult to accurately calculate expiry dates for US patents, and be confident in your answer? Some countries even calculate it for you and display it in a field in their online databases. Publication of US4762129B1 publication Critical patent/US4762129B1/en Assigned to BOSTON SCIENTIFIC CORPORATION reassignment BOSTON SCIENTIFIC CORPORATION ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS).Calculating patent expiries for most countries is relatively straightforward. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.) Filing date Publication date Family has litigation Priority to DE3442736 priority Critical Priority to DE3442736A priority patent/DE3442736C2/de Application filed by Tassilo Bonzel filed Critical Tassilo Bonzel Application granted granted Critical Publication of US4762129A publication Critical patent/US4762129A/en First worldwide family litigation filed litigation Critical (B1) 'Global patent litigation dataset” by Darts-ip is licensed under a Creative Commons Attribution 4.0 International License. Original Assignee Tassilo Bonzel Priority date (The priority date is an assumption and is not a legal conclusion.

Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.) Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.) Expired - Lifetime Application number Inventor Tassilo Bonzel Current Assignee (The listed assignees may be inaccurate.

Us patent 6183297