“[W]hether the order of a federal district court granting summary judgment of non-infringement in favor of one of several defendants in a pending patent infringement suit is immediately appealable.”
“[W]e conclude that, under Carson, an interlocutory order that, in effect, denies an injunction is appealable under ยง 1292(a)(1) only if such order causes serious, if not irreparable, consequence and can be effectually challenged only by immediate appeal.”
