Triangular opening not equivalent to vertical slit; summary judgment of no infringement affirmedNovember 28, 2007

Today the Federal Circuit affirmed a district court's determination that the patent claim term "closeable vertical opening" required a slit-like shape that is perpendicular to the pan of the horizon instead of simply an opening with a shape that is taller than it is wide. Further, the court found that an accused product which creates a triangle-flap opening did not operate in a substantially similar way or with a substantially similar result of the aforementioned patent claim term.More detail of Stumbo v. Eastman Outdoors, Inc. after the jump.Steve Stumbo brought suit against Eastman Outdoors and Ameristep Corp. for infringement of a patent for a portable and collapsible hunting shelter having a "closable vertical opening" to enter the shelter, which can be seen below.

Stumbo blindThe defendants moved for summary judgment, claiming their products did not infringe plaintiff's patent. The defendant's products utilized a triangular-shaped "loose door flap" that would zip diagonally upward from one corner of a wall of the shelter to the middle of the wall and then zip up the rest of the wall to another corner by changing direction 90 degrees. In its analysis, the district court construed the term "closeable vertical opening" to mean "a slit-like opening that runs straight up and down or perpendicular to the pan of the horizon." Based on this construction, the district court held that the accused product did not infringe literally because it had triangularly-shaped openings, not vertical openings. Further, the court found the defendants did not infringe under the doctrine of equivalents, as the patent could not cover triangular openings because (1) it did not operate in substantially the same way or with the same result as the patent, (2) it would have been covered by prior art, and (3) it would vitiate the "vertical opening" element in the patent. Thus, the district court granted summary judgment; Stumbo appealed. On review, the Federal Circuit first evaluated the district court's claim construction of "closable vertical opening." The plaintiff argued on appeal that "vertical" simply limited the opening to shapes that are taller than are wide, instead of its common meaning of being perpendicular to a primary axis or plane. The Federal Circuit disagreed, stating that if the plaintiff's construction were to be used, it would render another part of the claim language that mentioned the opening "along one of said side edges" and "along one vertical corner" superfluous. Instead, it found that only "if 'vertical' refers to the shape of the opening instead of redundantly to the orientation of the opening would each claim term have a distinct meaning." The court also looked at the specification, noting that it described how the legs of the shelter must flex in order for entry to take place. Triangular flaps like those in the accused products, however, did not require flexing legs. Therefore, the specification inherently required a slit-like shape that expanded when the legs flexed. Under this construction, it was undisputed that the accused products did not literally infringe.The Federal Circuit also rejected Stumbo's arguments regarding infringement under the doctrine of equivalents. The court held that the plaintiff failed to raise any genuine issues of material fact as to whether the accused products could meet the function-way-result test. Examining the testimony presented by the defendants regarding the requirement for leg flexing, a different way of operation than in the accused devices. Further, the court noted that the evidence showed that a triangular opening would allow wider access and be safer than a slit. While the plaintiff argued that a triangular flap's increased safety was irrelevant because the patented claim language did not mention any reference to that kind of result, the court disagreed. The court noted that when the claims and specification of a patent are silent as to the result of a claim limitation, the court should turn to the ordinary skilled artisan to determine its result. Thus, it looked at the testimony offered by the defendant, and found that there was a substantially different way and result. In response, the plaintiff offered testimony of its engineering expert that the openings were "not significantly different," but the court felt those statements were simply cursory conclusions that could not withstand summary judgment. Therefore, it affirmed the district court's grant of summary judgment of no infringement. Because it found that function-way-result test could not be met, the court did not address the issues relating to the prior art limiting the range of equivalents available or claim vitiation. To read the full decision in Stumbo v. Eastman Outdoors, Inc., click here.

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