The tape measure has been around for a while. Since 1868 to be more precisely. Yet, on 3 January 1922, Hiram A. Farrand received patent US1,402,589 for his concave tape, which was a major improvement for spring pocket tape measures. Finally the product became a success..
A success indeed, a rough estimation of the numbers sold is about 200 000 000… two hundred million…
Just think whenever you have a good idea… how much it may sell… and how nice it is to have the exclusive rights to it….