The Rothschild Petersen Patent Model Museum in Cazenovia, New York is the world's largest publicly-viewable private collection of models made as part of patent applications. The museum's new book, Inventing a Better Mousetrap, is due out later this year.
Above is a cracker making machine. From the museum's description:
The patent models journey began shortly after the birth of the United States. The Patent Act of 1790 required that anyone applying to the U.S. Patent Office for a patent, submit a model of the their invention. Over 200,000 models were submitted during the subsequent 90 years, but after two fires and a growing lack of space, the model requirement was abolished in 1880.
Congress permitted the Smithsonian Institution to select some models, but the bulk was sold at auction in 1925. The winning bidder was Sir Henry Wellcome, founder of Wellcome Pharmaceutical Company (now known as Glaxo Smith Kline). After Wellcome's death, the collection was broken up and thousands of models were sold off by a succession of private owners.
Alan Rothschild acquired the remainder of the original collection in the 1990s from aerospace engineer, Cliff Petersen, and established the Rothschild Petersen Patent Model Museum in 1998.