Potts v. Cur-Tech LLC
Literal infringement requires that the accused device embody every element of the claim, and infringement under the doctrine of equivalents requires that the accused device perform substantially the same function in substantially the same way to obtain the same result. In May 2008, the U.S Patent and Trade Office issued the '670 patent, which covers a wastewater system. The plaintiffs, David Potts and Geomatrix LLC, sued the defendant, Cur-Tech LLC, alleging that the defendant sold a CTL wastewater system that violated the '670 patent. The CTL wastewater system has a four- by eight-foot concrete chamber with box-shaped plastic appendages, or fins, along the sides. Each fin is open at the bottom and abuts an opening in the concrete chamber. In June 2008, Cur-Tech's founder obtained the '212 patent for an early version of the CTL system that had triangular appendages, or fins. The outside of the fins have pins that extend into the soil and that hold filter fabric away from perforations. The plaintiffs argued that the space between the exterior fin and filter fabric constitutes a channel and that the pins that protrude from the fins and the filter fabric create a geonet. The court found that the CTL wastewater system does not literally infringe the '670 patent, because it does not include a geonet. The '670 patent describes a system in which fluid drips from pipe through channels, drawing air into a 90 to 95 percent void and allowing aerobic breakdown and decomposition of waste. In contrast, the CTL wastewater system does not contain a channel with repetitive elements that creates a 90 to 95 percent void and aerobic conditions for effluent breakdown. It does not treat or decompose waste. The court also found that because the fins in the CTL wastewater system play a role that is substantially different from that of the geonet, the CTL wastewater system does not infringe the '670 patent under the doctrine of equivalents. The court granted the defendant's motion for summary judgment.