I have attempted to test the validity of the technique for establishing dates for UK radio sets by cross-referencing various UK radio sets against issue dates for their assosciated patents. You can even read the original patents if you are interested!
The United States patent number for each year is the first patent issued that calendar year.
is a publicly held Internet telephony service provider, providing business and residential telecommunication services based on voice over Internet Protocol (Vo IP).
The company was founded in 2001 and is headquartered in Holmdel Township, New Jersey.
If you only have a pre-1976 patent date, you also may be able to find the patent if you can hit upon the correct class for the item (see "Tools to Help..." above) and track the patent down, hit and miss.