National Recovery Techs, Inc. v. Magnetic Separation Systems, Inc., No. 98-1134, 1999 U.S. App. LEXIS 1671 (Fed. Cir. Feb. 4, 1999).




1. Whether the patent at issue requires one of ordinary skill in the art to unduly experiment in order to determine which radiation signals did not pass through irregularities in the container thereby making the patent claim invalid for lack of enablement.

2. Whether a claim is invalid for lack of operability because the invention does not work perfectly under all conditions.


1. Yes. The patented invention is not sufficiently disclosed to enable one skilled in the art to reduce the claimed invention to practice.

2. No. A claim for a machine that is imperfect in its operation is valid if the machine patented embodies the general principle and is functional.


National Recovery Technologies, Inc. ("NRT") appeals from the judgment of the trial court granting summary judgment to Magnetic Separation Systems, Inc. ("MSS"), holding that U.S. Patent No. 5,260,576 ("the '576 patent") is invalid for lack of enablement under 35 U.S.C. § 112 (1994). The '576 patent, assigned to NRT, is directed to a method and apparatus for separating materials (such as containers made from recyclable plastics).

The method described in the patent specification covers a process that distinguishes and separates materials based on the quantity of electromagnetic radiation that passes through the material. This method is used in the recycling industry in the separation of plastics and is possible since different types of plastic allow different amounts of radiation to pass through. The process is complicated by the fact that many of the containers in the recycling industry contain thicker portions of plastic in the neck of the bottles and contain irregularities as a result of deformations of the bottles. The radiation signals that pass through these irregular portions may appear to be that of a different type of plastic and thereby result in an erroneous classification. The prior art for the process was not able to determine if the signal radiation passed through thicker or irregular areas of the container.

The '576 claimed invention was an improvement over the prior art in that the claimed invention irradiated the containers at several points in their length and had a means for "selecting for processing those of said process signals which do not pass through irregularities in the bodies of said material items." National Recovery, at para 10. The Federal Circuit determined that the term "select," in absence of evidence in the patent to show otherwise, should be given its plain meaning. The appeals court rejected NRT's argument that the district court required the patent to work perfectly under all circumstances and focused on whether a person of ordinary skill in the art could practice the invention without undue experimentation. The Federal Circuit concluded by using the plain meaning of the term "select," and without sufficient instructional information in the written description of the patent, the specification of the '576 patent was not such as to enable one skilled in the art to select the proper process signals to make and use without undue experimentation the claimed invention.