IP Law Daily Claims disclosing strategy for controlling hybrid vehicles were obvious over prior art
News
Friday, April 21, 2017

Claims disclosing strategy for controlling hybrid vehicles were obvious over prior art

The patentees of an invention that described a control strategy for powering hybrid vehicles failed to show that the Patent Trial and Appeal Board had erred in ruling, in two inter partes review (IPR) proceedings initiated by Ford Motor Company, that 34 claims of U.S. Patent No. 8,214,097 were unpatentable as obvious over prior art, the U.S. Court of Appeals for the Federal Circuit has ruled. Because the Board’s claim construction and factual findings were sufficiently supported by the record, the decisions of the Board were affirmed (Paice LLC v. Ford Motor Company, April 21, 2017, Taranto, R.).

Claim construction. Paice argued that the Board had erred in construing the term "setpoint" to mean a "predetermined torque value that may or may not be reset." The Federal Circuit noted that it had recently affirmed the same construction that the Board had proffered in a related IPR proceeding involving another Paice patent in the same family. Because the patent in that proceeding was closely related to the patent under review, the court affirmed the Board’s construction of "setpoint."

Paice also argued that the Board had incorrectly read a group of claim elements as "unrelated requirements" rather than a "coordinated control strategy." According to the court, none of the claims at issue required the simultaneous control that was urged by Paice, such that the Board’s reading would be incorrect under the broadest-reasonable-interpretation standard.

Severinsky and Anderson. The Board determined that 20 claims would have been obvious over a combination of two prior art references: Severinsky (U.S. Patent No. 5,343,970) and Anderson ("The Effects of APU Characteristics on the Design of Hybrid Control Strategies for Hybrid Electric Vehicles," SAE Technical Paper 950493 (1995)).

In challenging that determination, Paice focused on the requirement that the internal combustion engine "provide torque to the hybrid vehicle when the torque required to operate the hybrid vehicle is between a setpoint SP and a maximum torque output (MTO) of the engine." However, substantial evidence supported the Board’s finding that Severinsky disclosed that element by comparing the torque that was required to operate the hybrid to a setpoint to determine when to operate the engine rather than the electric motor.

Regarding the motivation to combine, the Board found that a skilled artisan would have been led to combine the basic hybrid control strategy of Severinsky with the known technique of slowing the engine transient (to maintain substantially stoichiometric combustion)—as taught by Anderson—because both references shared the same fundamental goals of reducing carbon emissions by maintaining a stoichiometric air-to-fuel ratio.

According to the court, the Board had substantial evidence for finding that a skilled artisan who was seeking to reduce emissions would have been motivated to combine the teachings of Severinsky and Anderson. Further, the Board had sufficient evidence to reject Paice’s contention that the Severinsky-Anderson combination would not have worked.

Paice argued that Anderson taught that slow engine transients were possible with series hybrids but not parallel hybrids (the type of hybrid that was disclosed in the ’097 patent). Series hybrids were vehicles in which the engine, motor, and wheels were arranged in a series so the motor alone would directly propel the vehicle, the court explained; parallel hybrids were vehicles in which the engine and motor were independently coupled to the wheels, allowing either the engine or the motor to directly propel the vehicle.

In the court’s view, the Board could have reasonably found otherwise. Significantly, Anderson described the control strategy involving fast power transients as an example of an "extreme" strategy—i.e., not the optimum strategy—on the "spectrum" of control strategies. Anderson also said that its teachings regarding the optimum strategy were not limited to series hybrids. On that evidence, the court could not say that substantial evidence was lacking for the Board’s reading of Anderson as disclosing the avoidance of fast transients in parallel hybrids.

Severinsky, Anderson, and Yamaguchi. Ford separately challenged three claims as obvious over Severinsky, Anderson, and Yamaguchi (U.S. Patent No. 5,865,263). Each of the three claims contained a requirement that the engine be heated "prior to supply of fuel for starting the engine."

Paice argued that a person of ordinary skill in the art would not have been motivated to combine Severinsky, Anderson, and Yamaguchi because Severinsky had expressly taught the operation of the engine at lower temperatures to decrease nitrogen oxide emissions. The Board concluded that the disclosure mentioned by Paice referred to the maintenance of a low operating temperature, not a low starting temperature, as the three claims required. The court agreed with the Board.

Takaoka. Three dependent claims added the requirement of "a fuel:air ratio of no more than 1.2 of the stoichiometric ratio for starting the engine." The Board found that Takaoka ("A High-Expansion-Ratio Gasoline Engine for the TOYOTA Hybrid System, 47 Technical Rev. 53 (1998)) disclosed that requirement. On that basis, the Board concluded that the claims were obvious over Takaoka. The court found that the Board’s assessment was supported by substantial evidence.

Severinsky and Takaoka. The Board decided that two claims were unpatentable as obvious over Severinsky and Takaoka. Paice challenged that decision by disputing: (1) the motivation to combine Severinsky and Takaoka and (2) the Board’s reading of Takaoka as disclosing the limitation of the rate of change in torque that was produced by the engine so fuel combustion occurred at a substantially stoichiometric ratio.

The court rejected Paice’s challenge. Ultimately, the record supported the Board’s finding that a person of ordinary skill in the art would have been motivated to combine Severinsky and Takaoka because both references were concerned with improving fuel economy and reducing emissions in hybrid vehicles. Moreover, the Board’s finding that Takaoka disclosed a control strategy for limiting engine torque was, in the court’s view, reasonable.

Katsumo. The Board found that dependent claim 33 would have been obvious in light of Katsumo (U.S. Patent No. 4,707,984). Claim 33 required that fuel and air be supplied to the engine "at a fuel:air ratio of no more than 1.2 of the stoichiometric ratio for starting the engine." Paice challenged the Board’s obviousness ruling on the ground that Katsuno taught an air:fuel correction amount, not an actual air:fuel ratio for starting the engine. The court concluded that Paice had failed to show that the Board lacked substantial evidence for its obviousness ruling on claim 33.

The case is No. 2016-1411.

Attorneys: Ruffin B. Cordell (Fish & Richardson, PC) for Paice LLC and Abell Foundation, Inc. Matthew J. Moore (Latham & Watkins LLP) for Ford Motor Company.

Companies: Paice LLC; Abell Foundation, Inc.; Ford Motor Company

MainStory: TopStory Patent FedCirNews

Back to Top

Interested in submitting an article?

Submit your information to us today!

Learn More