Hotchkiss v. Greenwood 52 U.S. (11 How.) 248 (1850) Hotchkiss, Davenport, and Quincy patented the clay doorknob. When Greenwood started making similar doorknobs, they sued him for infringement. Greenwood argued that Hotchkiss' patent was not valid because their invention was not nonobvious. A lot of people were using clay knobs for cabinets and things. And people were using doorknobs made of metal and wood. All Hotchkiss did was match up a standard doorknob mechanism to a clay knob. The US Supreme Court found for Greenwood and invalidated Hotchkiss' patent. The US Supreme Court found that the idea of using clay to make knobs was not a new idea. Nor was the general construction of a doorknob a new idea. The only thing that Hotckiss had done was take a regular doorknob mechanism and substitute a clay knob for a metal knob. The Court noted that is might make a cheaper product, it was not fundamentally different from anything currently on the market and therefore not patentable. "Unless more ingenuity and skill in applying the old method of fastening the shank and the knob were required in the application of it to the clay or porcelain knob than were possessed by an ordinary mechanic acquainted with the business, there was an absence of that degree of skill and ingenuity which constitute essential elements of every invention. In other words, the improvement is the work of the skilful mechanic, not that of the inventor." This case was the first to define the concept of nonobviousness, which basically says that a patent will only be granted to something that is a novel invention, and not just a minor improvement. The current standard for nonobviousness is found in 35 U.S.C. §103(a). Prior to the Patent Act of 1952, Congress required only novelty and utility for issuance of patent, and never created any statutory requirement of nonobviousness.