'comprised of' is standard verbiage in US patents, and I am guessing he is trying to sound formal and official. Also see https://en.wikipedia.org/wiki/Comprise

'comprised of' is standard verbiage in US patents, and I am guessing he is trying to sound formal and official. Also see https://en.wikipedia.org/wiki/Comprised_of https://en.wikipedia.org/wiki/Comprised_of .