When does a design choice rise to the level of being a patentable invention? If someone builds a widget out of plastic and you decide to build it out of titanium, is that feature alone patentable? As a Florida Patent and Trademark Attorney, I am sometimes faced with this question when reviewing my client's inventions. The answer is not always clear. But yesterday's decision of the Board of Patent Appeals and Interferences (BPAI) provides a good explanation of how this concept is handled at the U.S. Patent and Trademark Office (USPTO).
Back in 2005, Volkswagen filed a U.S. patent application directed towards a heat shield sleeve for a drive shaft. One of the patent application's claims stated that the heat shield was formed out of aluminum. The Patent Examiner stated, among other things, this claim was obvious under 35 U.S.C. sec. 103 because the main prior art reference, a U.S. Patent referred to as "Mazuy," disclosed the use of steel for a heat shield and therefore the use of aluminum would have been "an obvious design choice." The BPAI disagreed, taking the Applicant's argument, supported by evidence, that substituting aluminum for steel in the heat shield of Mazuy would have resulted in a non-working heat shield. The BPAI further stated that the Examiner's rationale did not explain how the use of aluminum, instead of steel, would have produced a working gadget. It should further be noted that, as explained in the Manual of Patent Examining Procedure (MPEP), modifying a reference is not proper if "the modification renders the device of the primary reference inoperable for its intended purpose" (MPEP. 2143.01). Therefore, the BPAI reversed the Examiner's rejection of the patent application's claim directed to a heat shield formed of aluminum.
This case illustrates an important tool that should be kept in every patent practitioner's toolbox. Be sure to challenge an Examiner's assertion that a claimed feature is just an "obvious design choice." It may be that there is a good reason, like the expansion coefficient of a metal, for using a certain material over another, other than just a mindless design choice. Also, it may be that the Examiner's prior art reference, assuming it doesn't disclose your design choice explicitly, simply does not operate when it is modified to encompass your design choice. Winning on either of those arguments could result in a reversal of a Patent Examiner's rejection.
I found your blog very interesting. It's amazing how suttle changes can be overlooked in new patentable inventions. These days its hard to invent anything completely new.