Bradford loses to Smith at CAFC

From Smith vs. Bradford:

AOS Holding Company, which is wholly owned and controlled by A. O. Smith Corporation, owns U.S. Patent No. 8,375,897, titled “Gas Water Heater.” The two compa- nies (collectively, A.O. Smith), the only persons permitted to practice or profit from the invention embodied in the pa- tent, brought the present action against Bradford White Corporation in the U.S. District Court for the District of Delaware, alleging infringement of the patent’s claim 1 (the patent’s sole claim), which identifies a “method of in- terfacing a natural convection vent construction with a wa- ter heater.” ’897 patent, col. 6, lines 9–10. The district court held that Bradford White infringed claim 1 and that the claim was not invalid. Bradford White appeals both determinations. We affirm.


In its harmful-error argument, however, Bradford White contends that certain language in the district court’s findings and conclusions on the permitting limitation sug- gests a view—which Bradford White asserts is legal error, given the ’897 specification—that the “velocity or flow” of combustion products (in contrast to pressure) is simply im- material under the ’897 patent. Bradford White’s Br. at 36–38.We need not and do not decide whether Bradford White has adequately raised a legal argument along these lines, or whether it is correct in such an argument, for con- sideration independently of its challenge to the Category I venting claim construction, which we have rejected. Even if we so assume, we see no basis to set aside the court’s determination that the permitting limitation was met here. We read the district court’s opinion as relying inde- pendently on an evidentiary finding that reasonably as- signed little if any probative weight to the evidence regarding velocity presented in this case and instead found that the evidence based on pressure, together with the meaning of the Category I certification of the accused prod- ucts, proves satisfaction of the permitting limitation.