The U.S. Court of Appeals for the Federal Circuit, in a claim-construction decision based on imposition of the often cited but seldom successful principle of claim differentiation, held that the claim term “intermediary” in the independent claim should be given broader interpretation than in a narrower, dependent claim. Intamin, Ltd. v. Magnetar Techs., Corp., Case Nos. 05-1546, -1579 (Fed. Cir., Apr. 18, 2007) (Rader, J.).

Intamin is the owner of a patent that relates to a magnetic braking system for an amusement park rides such as drop towers and roller coasters. Intamin’s patent discloses one embodiment of the braking system in which two magnets are separated by a gap allowing the creation of eddy currents. A conductor, attached to the amusement park ride, passes in the gap between the magnets (and therefore the eddy currents) to create magnetic “friction” that slows and ultimately stops the ride. Magnetar’s accused product has magnets joined with rows of epoxy, with one magnet abutting another, i.e., where the intermediary material is magnetic. The rows of magnets are positioned in a metal tube or track that is attached to a movable car.

The dispute involves claim interpretation of the term “intermediary” between the magnets. The district court, citing to the prosecution history and the non-magnetic embodiment in the specification, held that the term “intermediary” had to mean something other than a magnet. Since Magnetar’s intermediary was magnetic, the district court held (on summary judgment) that it did not infringe. Intamin appealed.

The Federal Circuit reversed, looking to a dependent claim that added a limitation specifying that the “intermediary is non-magnetic.” Basing its decision on claim differentiation, the Federal Circuit reasoned that the drafter perceived a distinction between non-magnetic and magnetic intermediaries and that the term “intermediary,” in the independent claim, was intended to embrace magnetic substances subject to the alternating polarity. The Federal Circuit also noted that the single embodiment referring to the intermediary being non-magnetic did not limit the entire invention, but rather that the term “intermediary” embraced more than the limited disclosure in the specification.

A second issue in the case related to the sufficiency of the Rule 11 analysis performed by Intamin. Magnetar argued that Intamin filed a frivolous claim since it did not obtain Magnetar’s magnetic braking product and physically cut it open to analyze whether the product infringed. The record showed that since Magnetar’s magnets were inside tubes, a visual inspection would not disclose the orientation of magnets within the tubes. The district court held that there was no blanket rule requiring a patentee to obtain and thoroughly deconstruct a sample of defendant’s product to satisfy its Rule 11 obligation. The court stated that although there have been instances where the patentee could have easily obtained a sample of the accused device for a nominal cost and should have done so, the accused product in this case was not easy to obtain and the technology involved was sufficiently complex to preclude a requirement that the casing be obtained, opened and deconstructed. The Federal Circuit agreed.