People have tried to mash or purée foods since time immemorial. For centuries it was difficult to produce a smooth purée without lumps, because no effective utensils existed. Finally in 1928 Victor Simon from Belgium patented his passe-vite; and in 1932 Jean Mantelet from France his Moulinette presse-légumes – a real revolution at the time!
Food mills in which blades rotate horizontally (rather than moving up and down like a pestle) are particularly efficient, and this model from 1935 is a perfect example. It had instant success in a society where potatoes were still a staple food and increasing numbers of women were employed outside the home. Not to mention that the invention of tin facilitated the production and commercial distribution of inexpensive utensils of this kind. No more was needed for purées to take over the world!