While in college, David invented a new and useful machine to make macaroni and cheese (he called it the "Mac 'n' Cheeser"). It was like nothing on the market, but David did not apply for a patent. At that time, he offered to sell his invention to several kitchen products companies. His offers were all rejected and he never sold the invention. Years later, he decided to apply for a utility patent. Is David entitled to a utility patent?