Presumptions of patent scope

David Simonelli
Reising Ethington

We see stories in the papers every day about how patent wars are affecting the mobile device industry. These disputes are present in all industries as more and more entities search for ways to enhance the number below the bottom line. The medical device industries are no exception.

To maximize protection of an invention, one must carefully identify the scope of protection available. When I was being trained to draft patent applications, back in the 1980s, I was taught the broadest protection possible was obtainable by using two magic words: “means for” — which would invoke the means-plus-function provisions of the sixth paragraph of 35 U.S.C. §112. Anything under the sun that fit the function could be considered covered by the claimed element. As I was taught, the breadth of scope even extended to those things that were developed after the patent issued.

That all changed in 1997, when the United States Supreme Court clarified 35 U.S.C. §112, ¶6. The Supreme Court stated the invocation of “means for” provided a scope of protection only to the extent such equivalent elements were expressly disclosed in the specification of the patent in which the claim is a part. The claim scope was further limited by the disqualification of many embodiments through the inability to expand the scope of those items covered to include those deemed within the scope of the claim vis-à-vis the Doctrine of Equivalents. Suddenly, the tool employed by patent practitioners to encompass as much property as possible for its clients shriveled into a very limiting construct. Of course, most avoided “means for” claims from that point forward.

Since then, the courts have brought more reason into the interpretation of “means for” when used in a claim of a patent. There are now two judicially created presumptions. The first presumption is that when a claim includes “means for,” it is presumed that the drafter of the claim intended to invoke 35 U.S.C. §112, ¶6, — meaning the drafter intended to be specifically limiting in the scope of protection only to those embodiments described in the patent. The second presumption is that when a claim does not include the terms “means for,” it is presumed that the drafter did not intend to invoke 35 U.S.C. §112, ¶6 and will rely on the Doctrine of Equivalents to broaden the scope of the claim to those items not discussed in the patent. Id.

Even though these presumptions are rebuttable, the Court of Appeals for the Federal Circuit (CAFC) recently reiterated “that the presumption flowing from the absence of the term ‘means’ is a strong one that is not readily overcome.” In Flo Healthcare, the patent owner argued that “a height adjustment mechanism” for mobile computer workstations intended for medical care environments is a means-plus-function limitation that allowed the patent owner to include a length-adjustable vertical beam. It based this argument on the fact that the claim was void of structure and that the term “mechanism” is considered a common term used to invoke the means-plus-function provisions of the patent statute.

The CAFC looked to the description found in the patent (patent specification) and determined that there was sufficient reference to specific structure in the description (patent specification) to decide that there was ample evidence to support the presumption of not invoking the equivalents provided by 35 U.S.C. §112, ¶6. Therefore, the presumption was not rebutted and the scope of the claim was broadened to that which is provided by the Doctrine of Equivalents. As such, the claim was found to be invalid based on prior art determined to be within the scope of the claim as drafted. Flo Healthcare’s argument that the claim was limited to the structure in the specification fell on deaf ears as it is improper to bring the additional limitation (of being adjustable) into the claim when it was never there, regardless of the scope of equivalents provided.

The claims, drafted broadly by Flo Healthcare could not be saved even though Flo Healthcare attempted to limit them by invoking the means-plus-function provisions of the patent statute. Care must be taken when drafting a patent to make sure the eventual scope of protection equals that which a patentee is entitled. Otherwise, opportunities to secure assets (to be used to garner royalty payments, damages or injunctive relief) may be lost, resulting in a diminished number below the bottom line.


David Simonelli is a shareholder of Reising Ethington. He has participated in panel discussions with European patent attorneys on the harmonization of the intellectual property laws between the United States and other countries worldwide, was a delegate to the United Nations for the World Summit for the Information Society (WSIS), and authored a treatise that was presented at the 2005 WSIS Tunis Summit.