Safety Pin

A safety pin is a variation of an ordinary pin that adds a coiled spring mechanism and a clasp, so the point stays fastened shut and covered when not in use, protecting the wearer from being pricked. It was invented by the American mechanic Walter Hunt, who received United States patent number 6,281 for it on April 10, 1849, forming the pin from about eight inches of brass wire with a coil at the center to provide spring tension and a clasp to shield the sharp end; Hunt sold the patent for 400 dollars, primarily to settle a fifteen-dollar personal debt.