Executive Intellectual Property Bulletin

MEANS PLUS FUNCTION CLAIMS - 35 U.S.C. §112, ¶ 6

Cole v. Kimberly-Clark Corp. 41 USPQ2d 1001 (Fed. Cir. Dec. 6, 1996)

In a recent CAFC decision affirming a summary judgement in favor of the defendant, Kimberly-Clark, the court helped further define when a claim is not to be interpreted as a means plus function claim.

Cole obtained a patent for training briefs that tear from the leg bands to the waste band in case of an accident for easy removal of the briefs. In the patent, Cole disclosed scoring, scored sides, and perforations as the structures for allowing the tearing. KC sold training briefs that tear at bonded seams.

At issue was the interpretation of an element of the claim in suit: "perforation means extending from the leg band means to the waist band means through the outer impermeable layer means for tearing the outer impermeable layer means" The Patent Act of 1952 was enacted to overrule the Haliburton case, which found a claim using means plus function language indefinite:

"An element in a claim for a combination may be expressed as a means or step for performing a specified function without the recital of structure, material, or acts in support thereof, and such claim shall be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof."

Thus, the Court must construe the functional language to cover only the corresponding structure, material or acts for performing the function, and equivalents thereof.

The issue of whether a claim is a §112, ¶ 6 claim is important in determining infringement. Few cases have been decided directly on point. If a claim is a §112, ¶ 6 claim, it may provide a path to obtaining a jury trial, as the determination of "equivalents" to the structure set forth in the specification is a fact to be determined by the jury. It is very important in determining the scope of your claim, since broad functional language which is found not to be a §112, ¶ 6 claim can provide a literal reading and provide the ability not to have to resort to the complicated doctrine of equivalents. It determines whether a claim may literally read on a device.

In holding that perforation means is not a means plus function claim element, the court stated: "The district court correctly ruled that the claimed "perforation means...for tearing" is not a means-plus-function element under §112, ¶ 6..." Id. at 1006

"We decide on an element-by-element basis, based upon the patent and its prosecution history, whether §112, ¶ 6 applies. See Palumbo, 226 USPQ at 8 (Fed. Cir. 1985) (courts should consider prosecution history when construing "means-plus-function" claims)." Id.

The court then stated: "For example, the ‘perforation means... for tearing' element of Cole's claim fails to satisfy the statute because it describes the structure supporting the tearing function (i.e., perforations). The claim describes not only the structure that supports the tearing function, but also its location (extending from the leg band to the waist band) and extent (extending through the outer impermeable layer)." "To invoke this statue, the alleged means-plus-function claim element must not recite a definite structure which performs the described function." Id

The court went on to construe the claim language "perforation means" by looking at the dictionary meaning of perforation. The court then performed an analysis of the file history. It found that "The only thing Cole expressly surrendered when distinguishing the Roberts patent was stitched seams when she argued that perforations are not stitched seams." Id at 1007. One might question why a resort to the file history was made, when the element was found not to be in §112, ¶ 6 format. All that was required was to indicate that the claim did not literally read, since bonds are not perforations. Then, under the doctrine of equivalents, use the file history to limit its application, as in fact they do when considering it in the opinion.

In any event, the lessons to be learned from this case are many. If you use functional limitations in a claim element, it may be found to be a §112, ¶ 6 claim element even if you don't precisely state the claim in "means-plus-function" format. If you recite too much structure, you may have tried to draft a §112, ¶ 6 claim, but it may end up not being one. The lesson for drafters of applications is to provide a broad variety of claims, and if means plus function claims are intended, keep them functional and describe lots of structure, materials or acts in the specification.

We encourage you to contact the author of this bulletin, Bradley A. Forrest, Esq., at (612) 373-6972, or any other attorney at Schwegman, Lundberg & Woessner, should you have any questions regarding means-plus-function claims, or any other issue regarding intellectual property and how if affects your business.

For more information on this topic or any other topic, please contact any of the attorneys at Schwegman, Lundberg & Woessner, P.A. at 612-339-0331 or by facsimile at 612-339-3061 or via this website.