Legend has it that, in 1849, a mechanic named Walter Hunt owed a friend $15 and decided to invent something new in order to earn the money to repay him. He invented the safety pin. On April 10, 1849, Hunt received a US patent for his invention. The anniversary of the day when the patent was issued is informally celebrated as Safety Pin Day. Hunt sold his patent to W. R. Grace and Company, earning $400.
Strong and sharp, yet safe enough to be used on clothing, safety pins are a simple yet ingenious invention, which practically everyone has used at least once in their life.
A safety pin, also referred to as a baby pin, is a variation of the regular pin. Its main difference from the regular pin is that it includes a simple spring mechanism and a clasp. The clasp covers the sharp point of the pin and keeps it from opening. It simultaneously holds the pin in place and protects its user from being pricked by the sharp point.
Through the course of his work Hunt became renowned for being a prolific inventor, notably holding patents on the lockstitch sewing machine, a forerunner of the Winchester repeating rifle, a successful flax spinner, knife sharpener, streetcar bell, hard-coal-burning stove, artificial stone, street sweeping machinery, an ink well, fountain pen, nail making machine, and the ice plow.
Regarding the above mentioned sewing machine (Patent Number 11,161), Hunt is said to have initialy failed to patent his sewing machine because he feared it would create unemployment among seamstresses. (This led to an 1854 court case when the machine was re-invented by Elias Howe. Hunt’s machine was shown to have design flaws that limited its practical implementation).