Broadest-Construction Rubric Coupled with Term "Comprising" Does not Give USPTO Unbridled License to Expand Scope of Claims

The Court of Appeals for the Federal Circuit ("CAFC") held in In re Suitco Surface, Inc., 2009-1418 (CAFC, April 14, 2010) that the "broadest broadest-construction rubric coupled with the term “comprising” does not give the PTO an unfettered license to interpret claims to embrace anything remotely related to the claimed invention. Rather, claims should always be read in light of the specification and teachings in the underlying patent. See Schriber-Schroth Co. v. Cleveland Trust Co., 311 U.S. 211, 217 (1940) (“The claims of a patent are always to be read or interpreted in light of its specifications.”).

The CAFC remanded the US Patent and Trademark Office ("PTO") claim interpretation that was made during a reexamination proceeding.  The reexamination was for US Patent 4,944,514 ("the '514 patent"), the representative claim 4 follows:

4. On a floor having a flat top surface and an improved material for finishing the top surface of the floor, the improvement comprising:
at least one elongated sheet including a uniform flexible film of clear plastic material having a thickness between about one mil and about twenty-five mils and
a continuous layer of adhesive material disposed between the top surface of the floor and the flexible film, the adhesive layer releasably adhering the flexible film onto the top surface of the floor. (emphases added).

During reexamination, the Board of Patent Appeals and Interferences ("the Board") affirmed the patent examiner's rejection of claim 4 based on US Patent 3,785,102 ("Amos") or US Patent 4,543,765 ("Barrett").  Amos shows a plurality of plastic sheets, each containing an adhesive layer.  Individual layers are removed after they have been used to collect dirt or other debris from the soles of shoes by people entering a clean or sterile room.  Barrett shows the use of a clear plastic connected to a floor with an adhesive layer.  The clear plastic in Barrett is used to temporarily protect a floor during construction.

In its rejection, the Board construed the term “material for finishing the top surface of the floor” to mean “requiring a material that is structurally suitable for placement on the top surface of a floor.” Under that construction, according to the Board, the “material for finishing the top surface of the floor” could be any layer above the floor regardless of whether it was the top or final layer. The Board also construed the term “uniform flexible film” to mean “including, for example, a flexible film having the same thickness throughout, as well as a flexible film having the same textured surface throughout.” 

The CAFC disagreed, stating the express language of the claim and the specification require the finishing material to be the top and final layer on the surface being finished. See, e.g., ’514 patent, col.1 ll.15-20 (“The present invention is directed generally to a material and method for quickly and easily producing a transparent wear resistant finish on a smooth flat surface subject to wear and more particularly to a material and method for finishing a floor . . . .”). The PTO’s proffered construction therefore fails.  Slip Opinion at pages 8-9.