Can opener . It consists of a metal blade that slides along the edge of the can cutting the metal , this action allows you to open it and access the food preserved with this method, although there are electrical or manual, depending on the model, the blade is attached to a wooden endand another resistant material, that allows to exert the necessary pressure for the opening of the container. Some models have two ends or manipulators in the form of tweezers and toothed rollers, which help by rotating against the outer edge of the can to slide the blade through the inside of it, this type being one of the most generalized. In other cases, openers incorporate various functions, such as hooks or teeth to remove sheets, corks or make holes. This domestic utensil is present in almost all homes, its name comes precisely from the function it performs, and despite the facilities of modern canning for its opening, it is still a very useful tool.
The origin of this utensil is closely linked to the appearance of canned food, although openers appeared a little after four decades, since in 1811 the French Nicolas Appert produced preserved food with this method. The first openers begin to appear in the mid- 19th century , many ascribe their invention to Ezra. J. Warner from Waterbury, Connecticut who made it known in 1855 and patented it 3 years later, although it must be clarified that the model patented by it suffered many subsequent modifications, due to its dimensions and way of operating it, since it consisted of a kind of sicklethat was forced into the can to slide it later. Before this, knives, pocket knives and all kinds of objects were used to open the canned goods. In 1870 the American William W. Lyman patented a novel model that has lasted to this day, although the variants proliferate with some modifications, such as the cogwheel added in 1925 by the Star Can Opener Company of San Francisco, who patented years later the first electric model back in 1931