The term of a utility patent in the United States is typically 20 years from the filing date of the patent application. Once the patent protection period expires, other manufacturers are free to produce the patented product without needing permission from the patent holder.
Table of Contents
There are three patent information related to pop up timer Patent
Through the website https://patents.justia.com Searching for “VOLK POP UP”, we found three patent information as follows:
Pop-up temperature indicating device
Patent number: 5988102
Filed: December 24, 1997
Date of Patent: November 23, 1999
Pop-up temperature indicating device
Patent number: 5799606
Filed: November 7, 1996
Date of Patent: September 1, 1998
Two-stage pop up thermometer
Patent number: 4421053
Filed: December 18, 1981
Date of Patent: December 20, 1983
POP-UP TIMER is no longer protected by patent rights
After the expiration of the 20-year protection period from the filing date, these inventions of pop up timer are no longer protected by patent rights, and other manufacturers can produce similar products without infringing on the patents.