Federal Circuit Defines Terms Narrowly In View Of Limited Description And Broadly Using The Doctrine Of Claim Differentiation

On April 18, 2007, the Court of Appeals for the Federal Circuit handed down an opinion reaffirming the importance of broad language in patent specifications. In Intamin Ltd. v. Magnetic Technologies Corp., the court vacated a summary judgment by the district court. The court held first that narrowing language in the specification did not have a negative effect on the broader claims with respect to one limitation, and second that the lack of intrinsic evidence supported the district court’s reliance on plain meaning with respect to another limitation.

Intamin and Magnetar Technologies (Magnetar) both manufacture braking systems for amusement park rides, such as roller coasters. The braking systems at issue in the present case involved an array of magnets arranged along the rails of the roller coaster. When working in concert with a conducting rail, the magnets act as a brake on a passenger car riding along the rails. Magnetar manufactured a magnetic braking system called “Soft Stop”. In Magnetar’s Soft Stop system, a “Halbach array” of magnets is arranged along the rails. Each magnet in the array has a polarity rotated 90 degrees from the previous magnet. The magnets are arranged one after the other, with nothing substantial in between.

Intamin sued Magnetar, alleging that the Soft Stop brakes infringed U.S. Patent No. 6,062,350 (the ‘350 patent). Intamin alleged infringement of claim 1 of the ‘350 patent, which claims:

A braking device for use with an amusement apparatus having a fixed device part, at least one running rail secured to the fixed device part, and a movable device part including at least one traveling gear configured for movement along the at least one running rail, the braking device comprising:

an eddy current brake assembly including:

a conducting part having at least one conductive rail configured for attachment to the fixed device part, said at least one conductive rail being adapted to extend the length of the fixed device part;

an energizing portion having at least one yoke aligned in correspondence with each said at least one conductive rails, each said yokes including a pair of yoke arms for receiving said at least one conductive rail therebetween; at least one pair of carrying rails extending a predetermined distance along the direction of said at least one conductive rail, each said carrying rails being mounted on corresponding yoke arms of said plurality of yokes;

a plurality of magnet elements mounted on each of said carrying rails with alternating polarities, said plurality of magnet elements being further arranged such that the poles of magnet elements mounted on one carrying rail have opposite polarities from the poles of magnet elements mounted on a corresponding carrying rail of said at least one pair of carrying rails; and

an intermediary disposed between adjacent pairs of said plurality of magnet elements;

wherein:

an interferric gap is defined between each said yoke arms and the at least one conductive rail, and

movement of the movable device part, relative in the fixed device part, induces eddy currents that create a magnetic brake force between said conducting part and said energizing part.

The limitations at issue on appeal were the “intermediary disposed between adjacent pairs of said plurality of magnet elements” and the “conductive rail being adapted to extend the length of the fixed device part”.

The district court granted Magnetar’s motion for summary judgment of non-infringement. In interpreting the limitations of claim 1, the court held that the Soft Stop brakes did not include an “intermediary” and did not have a conductive rail “extending the length of the fixed device part”. Intamin appealed. The Federal Circuit vacated the summary judgment ruling, affirming the district court’s interpretation of the “conductive rail” limitation but reversing the interpretation of the “intermediary”.

The Intermediary Limitation

The district court, in granting Magnetar’s motion for summary judgment, held that the “intermediary” could not be a magnet. The district court relied on a description in the specification of an embodiment having a non-magnetic intermediary. The Federal Circuit reversed.

The Federal Circuit based its decision on the doctrine of claim differentiation. Under the doctrine of claim differentiation, each claim in the specification should be interpreted so as to have a different meaning. In the ‘350 patent, claim 2, which depended on claim 1, defined the intermediary as being non-magnetic. Applying the doctrine of claim differentiation, the Federal Circuit concluded that claim 1 should be interpreted as having a broader scope, encompassing magnetic intermediaries.

The Federal Circuit disagreed with the district court’s reliance on the narrow embodiment disclosed in the specification. The narrow disclosure in the specification did not foreclose the possibility of a broader claim, since the specification disclosed only one possible embodiment of the invention. Although this particular embodiment had a non-magnetic intermediary, the context of the patent as a whole contained no disavowal of the possibility of magnetic intermediaries. Absent such a disavowal, the claims should be interpreted broadly.

The Federal Circuit punted on another remaining issue, whether the particular arrangement of magnets in Magnetar’s Soft Stop brakes was an intermediary. According to the claim, the intermediary is between two magnets having “alternate polarities”. Intamin argued that the magnets had to have opposite polarity, or magnets having a polarity rotated 180°. Magnetar argued that the magnets merely had to have a different polarity. The adjacent magnets in the Soft Stop brakes have a polarity rotated 90° with respect to one another. Under Intamin’s interpretation, two magnets in the Soft Stop brakes having a polarity rotated 180° with respect to one another would be separated by an intermediary magnet, albeit with a different interpretation. Under Magnetar’s interpretation, the Soft Stop brakes have no intermediary, since two magnets with alternating (different) polarity abut each other with nothing in between. The district court, however, did not reach this issue. The Federal Circuit remanded to the district court to provide the court with an opportunity to resolve the disputed interpretation.

Length Limitation

In contrast to the district court’s interpretation of the “intermediary” limitation, the Federal Circuit upheld the district court’s interpretation of the term “length” as applied to “at least one conductive rail being adapted to extend the length of the fixed device part”. The Federal Circuit held that the district court properly used extrinsic evidence to interpret the term “length”; in this case, the plain meaning of the word “length”.

According to the district court, the plain meaning of the word “length” was the full length of the fixed device part. The conductive rail had to run the entire length of the track it was attached to. The Federal Circuit agreed. Although intrinsic evidence (evidence found in the specification or prosecution history) is favored over extrinsic evidence (everything else), no intrinsic evidence in the ‘350 patent contradicted the plain meaning of the term.

Intamin argued that the term “length” should be interpreted to mean the orientation of the conductive rail with respect to the fixed part. However, the Federal Circuit, like the district court, found no intrinsic evidence to support this argument. Indeed, the intrinsic evidence in fact appeared to bolster the plain meaning. The use of the word “extend” appeared to indicate that the conductive rail extended from one end of the fixed device part to the other. And, when the specification referred to an orientation as opposed to a distance, the specification used different language, such as “along drop directions”. In the absence of intrinsic evidence to the contrary, the district court was free to use the plain meaning of the term “length”. The Federal Circuit accordingly upheld the district court’s interpretation of the “length” limitation.

RULE 11(B) Pre-Filing Investigations

Finally, the Federal Circuit upheld the district court’s denial of Magnetar’s motion for sanctions under Rule 11(b). Magnetar alleged that Intamin had failed to make a good faith investigation of the Soft Stop brakes prior to bringing the suit. The district court disagreed and the Federal Circuit affirmed.

A patent owner must conduct a “reasonable and competent” inquiry prior to bringing an infringement suit. Magnetar alleged that Intamin had failed to perform such an inquiry because Intamin had not opened up the casing on the magnets in the Soft Stop brake system to determine whether the magnets were arranged in an infringing manner. The Federal Circuit refused to require such an intensive investigation. Patentees, the Federal Circuit held, do not need to conduct a thorough investigation of the potentially infringing product, especially where, as in the instant case, such an investigation would present “unreasonable obstacles” (cutting open a metal case to examine the magnets inside.) Instead, Intamin properly reviewed roller coasters having the Soft Stop system installed, examined publicly available materials on the Soft Stop system, photographed the brakes, and consulted with experts. These efforts were enough to qualify as a good faith investigation, given the unreasonable obstacles to a physical investigation.

Impact on Patent Prosecution

The Intamin case highlights the importance of a good specification. A narrow limitation does not necessarily spell doom for a patent infringement suit, though where a narrow example is given in the specification, care should be taken to ensure that the narrow limitation is not so prevalent as to imply a disavowal of broader terms. Reasonable alternative interpretations of a claim term having multiple well-known meanings should also be included in the specification. “Length”, for example, has two well-known meanings, one for distance, another for orientation. Intamin lost on the interpretation of that term largely due to its failure to broadly define the term in the specification. As the Intamin case indicates, a broad specification leads to broad claim interpretation and fewer problems in litigation.

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