The U.S. Patent Act protects physical characteristics of inventions through design patents. Many products are protected by a patent on the technology as well as by a patent on the physical layout and appearance of the product. The U.S. Patent and Trademark Office asks manufacturers to print the patent number on the product to show the product and its design is patented. The USPTO also maintains a public searchable database of all patents ever issued.
Examine the product for a patent number. A properly labeled product should include either "patent" or "pat" followed by a number. Many products list multiple numbers, one of which is often a design patent.
Go to the USPTO's patent database and click on the "Quick Search" link in the upper left sector of the page.
Enter "design" into the "Term 2" box and select "Application Type" from the drop down menu. Your search will turn up a result only if the number refers to a design patent. If you get a result, check the technical drawings at the bottom of the patent to see if they match the product; if they do the product's design is patented.
Searching the Database
Enter the product's name into the "Term 1" box of the database. The database allows you to search using keywords, which may be helpful if the product does not have any patent numbers printed on it.
Enter "design" into the "Term 2" box and select "Application Type" from the drop-down menu.
Run searches using keywords for the product (name, category—"pencil sharpener," for example—or description) and limiting your results by keeping "design" and "Patent Application" in the "Term 2" search. If your searches do not turn up a design patent that clearly shows the product in the technical drawings, the product's design is not patented.