One of the first shopping carts was introduced on June 4, 1937, the invention of Sylvan Goldman, owner of the Humpty Dumpty supermarket chain in Oklahoma. One night, in 1936, Goldman sat in his office wondering how customers might move more groceries. He found a wooden folding chair and put a basket on the seat and wheels on the legs. Goldman and one of his employees, a mechanic named Fred Young, began tinkering. Their first shopping cart was a metal frame that held two wire baskets. Since they were inspired by the folding chair, Goldman called his carts "folding basket carriers". Another mechanic, Arthur Kosted, developed a method to mass-produce the carts by inventing an assembly line capable of forming and welding the wire. The cart was awarded patent number 2,196,914 on April 9, 1940 (Filing date: March 14, 1938), titled, "Folding Basket Carriage for Self-Service Stores". They advertised the invention as part of a new “No Basket Carrying Plan. " Goldman had already pioneered self-serve stores and carts were part of the self-serve retail concept.