Searching the USPC: Proximate Function

For novice patent searchers one of the most difficult concepts in the U.S. Patent Classification system is the idea that inventions can be classified on the basis of "proximate function." Proximate function is one of four schemes in the USPC used to classify subject matter disclosed in patents and published applications. The other three are "industry or use," "effect or product" and "structure." The rationalie behind proximate function is that "similar processes or structures that achieve similar results by the application of similar laws of nature to similar substances are considered to have the same fundamental utility and are grouped together." (See the Handbook of Classifiction.) For example, a refrigeration system used to cool beer and a refrigeration system that cools milk are treated the same under the USPC.

The patents of A.C. Gilbert, inventor of the Erector Set, offer another example of proximate function at work. Gilbert's inspiration for the Erector set was real-life construction sites he saw around his home in New Haven, Connecticut. Many of his patented inventions are simply scaled-down versions of construction materials such as beams, girders, brackets, trusses and rivets. Consequently, you can find Gilbert's patents classfied under both Class 446, Amusement Devices: Toys, and Class 52, Static Structures (Buildings). Because of the concept of proximiate function a search for patents for construction toys should include the appropriate subclasses from both classes. A third search possibility is the design class D21, Games, Toys and Sports Goods; subclasses 484-505 specifically relate to construction-type toys.

A.C. Gilbert - Inventor of the Erector Set and the "man who saved Christmas"

The other day when I was channel surfing I happened across a movie called The Man Who Saved Christmas, starring Jason Alexander as Alfred C. Gilbert, the inventor of the Erector set, one of the classic American toys of the 20th century. Gilbert became known as the "man who saved Christmas" during World War I when the U.S. government was considering a ban on the production of toys in order to support the war effort. Gilbert appeared before the Council of National Defense and successfully argued against the ban.

Gilbert was a Yale graduate and amateur magician who started with his partner John A. Petrie a business for producing magic tricks and apparatus. The company was named the Mysto Manufacturing Co. and based in New Haven, Conn. On Dec. 5, 1911, Petrie patented a disappearing cigarette trick (US1010794) and assigned the rights to Mysto. Gilbert's interest, however, soon turned away from magic and to construction toys. On Jan. 20, 1913, he applied for a patent for toy construction blocks. The application described toy building blocks made of strips of sheet metal and the means of fastening them together with u-shaped couplings. The patent issued on July 8, 1913 (US1066809), the first of more than 150 patents Gilbert would receive for Erector set components and other toys. The A.C. Gilbert company (Gilbert changed the name in 1917) continued to produce Erector sets , train sets and other toys into the 1960s.

Whatever happened to Gilbert's partner John Petrie? He parted ways with Gilbert in 1913 shortly after the introduction of the Erector set. He continued to invent and in 1917 patented an lighted hand mirror (US1216724) and a sand-wheel toy (US1247145). The trail grows murky after that. A John W. Petrie, also of New Haven, Conn. (possibly a son?), received several patents from the 1920s through 1940s for toys, magic devices and other items. Many of these were assigned to the Petrie-Lewis Manufacturing Co.