As the reader may (should) remember, an article claim of a patent is infringed if all of the claim limitations are found in the accused product. Note that this statement is silent as to when the claim limitations must be present. A recent case turns on that fascinating – to patent attorneys – issue. Gemtron Corporation v. Saint-Gobain Corporation
Gemtron sued for infringement of a patent directed to a refrigerator shelf. The shelf comprised two pieces: a molded plastic “one-piece open frame” and a glass panel. The frame includes “relatively resilient” fingers allowing the glass panel to be “snap-secured” into place without any adhesive. As the glass panel is inserted into the frame, the resilient fingers flex outwardly, and then snap back to their original position, holding the panel in place. This flexing occurs only when the plastic frame is warm, such as when it has just emerged from the mold. If the frame is at room temperature, the shelf cannot be assembled.
As is often the case, the Court’s claim construction determined the outcome of the trial. The language of the relevant limitation, “relatively resilient end edge portion which temporarily deflects and subsequently rebounds to snap-secure ... [the glass panel to the frame]” (emphasis by the Court) was construed to mean “that the end edge portion must be sufficiently resilient that it can temporarily deflect and subsequently rebound when glass is being inserted into the frame” (emphasis added by yours truly).
Recently we – meaning yours truly – posted a blog pointing out that mixing article limitations and process limitations, in a single patent claim, rendered the claim invalid (see "It Isn’t Kosher"). In its defense, Saint-Gobain raised this issue, arguing that such a claim construction rendered the limitation a process one. The Court, nevertheless, held this to be a “structural attribute,” citing precedent that “even words of limitation that can connote with equal force a structural characteristic of the product or a process of manufacture are commonly and by default interpreted in their structural sense.”
The appellate court also noted that Saint-Gobain’s unsworn attorney argument – first made at oral argument in the appeal – is not evidence and that its failure to object, at trial, to the testimony of Gemtron’s technical expert precluded any attempt to have the appellate court reject it.
Score one for the little guy.
THE LESSONS TO BE LEARNED: (1) Determination of infringement is not just a question of “if,” but also “when”; and (2) introduce all of your evidence and make all of your objections at trial.