The Federal Circuit’s opinion in Hamilton Beach Brands, Inc. v. Sunbeam Products, Inc. reminds practitioners to be explicit in identifying the defenses that they will be relying upon. Specifically, the majority did not address an experimental use defense to an on-sale bar allegation. Despite references to facts supporting an experimental use defense, the patentee did not use the catchphrase “experimental use” in presenting its defense, and the majority declared that the defense had not been raised.
Under the pre-Leahy-Smith America Invents Act (AIA), a patent can be held invalid based on an on-sale bar. In Pfaff v. Wells Elecs., Inc., the Supreme Court set forth a two-prong test for an on-sale bar: (1) more than one year prior to the date of patent application in the United States, the invention was the subject of a commercial offer for sale; and (2) the invention was ready for patenting before the critical date. An experimental use defense, however, negates any sale or offer for sale if the primary purpose of the transaction was experimental or developmental, e.g., EZ Dock v. Schafer Systems, Inc, Federal Circuit, 2002.