Addressing claim construction of a term with disputed grammar, the U.S. Court of Appeals for the Federal Circuit affirmed in part the district court’s construction and remanded the case, explaining that grammatical rules give way to the written description when construing claims.  3M Innovative Properties Co. v. Tredegar Corp., Case No. 12-1241 (Fed. Cir., August 6, 2013) (Reyna, J.) (Plager, J. concurring) (O’Malley, J. concurring-in-part, dissenting-in-part).

3M sued Tredegar Corp. for infringement of patents directed to multi-layer elastomeric laminates.  Such laminates may be found in the body-hugging areas of products such as the waistband or side tabs of disposable diapers.  Tredegar is a supplier of breathable and nonwoven film laminates for personal care products.

Resolution of the infringement issue turned on the meaning of the claimed phrase “continuous microtextured skin layer over substantially the entire laminate.”  After the district court, agreeing with Tredegar, found that the claim required the microtexturing to be continuous over the entire skin layer, the parties stipulated to non-infringement.  3M appealed.

On appeal, the parties disagreed as to whether “continuous” applied to the microtexturing, the skin layer or both.  3M, citing The Chicago Manual of Style, argued that if the applicant intended that the microtexturing be “continuous,” it would have used the adverb “continuously” instead of the adjective “continuous.”  Tredegar, also citing The Chicago Manual of Style, argued that adjectives separately modifying a noun are generally separated by a comma.

The Federal Circuit did not rely on this extrinsic evidence.  Instead, the Federal Circuit linked the “continuous microtextured skin layer” of the claims to the “unique continuous microtextured surfaces” of the written description and determined that the microtexturing is continuous, but not restricted to a single zone or region of the skin layer.

In a concurring opinion, Judge Plager also rejected 3M’s arguments regarding grammar, stating that “the nuances of comma usage, like 3M’s adverb argument, seem to me a tenuous foundation for an entire claim construction on which substantial liabilities may rest.”  However, Judge Plager did not agree that the written description provided sufficient clarity, pointing out that the phrase “continuous microtextured skin layer” does not appear anywhere in the specification.  Instead, Judge Plager proposed applying the contract drafting doctrine contra proferentem: “When a term is ambiguous, . . . the ambiguity should be construed against the draftsman.” Judge Plager proposed that, alternatively, claims introducing such ambiguities “should simply be invalidated as indefinite.”  Because the applicant “knew or should have known that the claim term . . . was highly relevant to the patented technology,” the applicant should have demonstrated this relevance in the disclosure.  Because the patent applicant has “the last clear chance” to avoid ambiguity in claim terms, the competitor “should not have the risk of guessing wrong about what a claim term could possibly mean.”

Dissenting-in-part, Judge O’Malley agreed with 3M that, based on “a natural reading of term, i.e., its plain and ordinary meaning,” the adjective “continuous” can only modify the “microtextured skin layer.”