The U.S. Court of Appeals for the Federal Circuit recently decided Ohio Willow Wood Co. v. Alps South, LLC (Fed. Cir. 2013), which involved various legal issues, including collateral estoppel, obviousness, and inequitable conduct. The collateral estoppel aspects of the case are of particular interest because the issue preclusion finding was based on a different, related patent.
Ohio Willow Wood (OWW) owns a family of patents relating to cushioning devices that are placed over the residual stumps of amputated limbs to make prosthetics more comfortable. OWW asserted its ‘237 patent against Alps, and the litigation was stayed pending reexamination. During the stay, OWW asserted its ‘182 patent (which is a continuation of the ‘237 patent) against another defendant (Thermo-Ply). The ‘182 patent was held to be invalid as obvious in the Thermo-Ply litigation. Based on that result, the district court in the Alps litigation granted summary judgment of invalidity of the ‘237 patent on a collateral estoppel theory. The Federal Circuit affirmed this decision, agreeing that both patents recited substantially the same cushion liner, albeit using slightly different language. The court held that the mere use of different words in portions of a claim do not create new issues of validity.
A careful approach to building a portfolio of related patents can help avoid this type of collateral estoppel issue. For example, when drafting continuation claims, practitioners should avoid simply rearranging words or replacing them with equivalents, and instead consider including features which are different from those covered in parent cases yet still read on competitor products.