There is a difference between impermissibly importing the specification’s limitations or preferred embodiments into the claims and simply giving meaning to the claim terms as they are used throughout the specification. In this case, while it is true that there was seemingly no need to limit the claims to welding “sheets” per se as the disclosed welding techniques were equally applicable to other materials, there is only so much leeway a court can give to save a patentee’s poor choice of claim terms. If you use an overly specific term, you are going to be stuck with it. Be careful to craft your claims around the “invention,” and not merely the inventor’s product.
Background / Facts: The patent at issue discloses a method of welding, using a laser or electron beam, more quickly and with fewer defects by focusing the welding beam in an oblong shape. Laserfacturing alleges that three of DaimlerChrysler’s laser welding stations at its transmission manufacturing plants infringe their patent, but the claims recite welding a “sheet.”
Issue(s): Whether the disputed claim term “sheet” may be broadly interpreted as simply an “element to be welded,” rather than the more narrow but customary definition of a “broad thin piece of material with generally uniform thickness.”
Holding(s): No. The patent consistently discusses the term “sheet” according to its plain and ordinary meaning (e.g., as undergoing “bending,” “another shaping or forming process,” being “uncoiled from coiled stock,” and so on). By staying within the term’s customary use, the intrinsic record does not support a definition that reaches beyond or differs from what one of ordinary skill in the art understands as “sheets.” Moreover, a broad meaning of the term would discount the claim’s choice of the word “sheets.”