What grace period do inventors have for testing their creations before applying for a patent? The U.S. Supreme Court has agreed to tackle the question and is expected to make a decision next year. According to federal law, an inventor cannot get an enforceable patent on an invention that has been "on sale" in the United States for more than a year before application for a patent. But what does "on sale" mean? The law's text is not explicit. Lower courts have ruled that "on sale" can begin whenever an inventor seeks or receives a commercial offer for the invention. Supreme Court justices will attempt to clarify the meaning in the case of Pfaff vs. Wells Electronics. Inventor Wayne Pfaff of Dallas contends that Wells Electronics Inc. of South Bend, IN, infringed his patent on a socket to hold semiconductor chips during testing. The U.S.Court of Appeals for the Federal Circuit ruled against Pfaff, because he had applied for the patent a year and 11 days after receiving an order for 30,100 of the sockets.