I have just come across this information on my late father's patent for an ice-making machine in the 1970's. I am his daughter, Virginia Anne Fitch (nee Karas) and was involved with his business Venturi Refrigeration before his death in 1995. Obviously a lot of time has elapsed since then but it never occurred to me to look up my father's past patents. Just want to check whether there is anything I should do now about his patents or how can I tell whether any other companies have either applied to use his patent or have used his patent without permission? Appreciate your advice so that I can put my mind at rest that I have done the right thing by my father. Many thanks.