American Axle: Another Section 101 Decision Divides the Federal Circuit

February 15, 2020

In American Axle & Manufacturing, Inc., v. Neapco Holdings, LLC (Fed. Cir. Oct. 3, 2019), a split Federal Circuit panel affirmed the district court’s grant of summary judgment holding claims from plaintiff’s patent ineligible under § 101.  Even among the many post-Alice Federal Circuit decisions that have fractured the court, American Axle stands out for several reasons.  Some background on the technology at issue helps to illustrate why. 

The plaintiff American Axle’s U.S. Patent No. 7,774,911 (“the ’911 patent”) relates to a method for manufacturing driveline propeller shafts (“propshafts”).  Propshafts are employed in automotive vehicles to transmit rotary power in a driveline.  Because propshafts are typically made of relatively thin-walled steel or aluminum tubing, they are prone to undesirable vibrations that can cause unpleasant noise. 

According to the ’911 patent, there are three kinds of vibrations that were encountered in the prior art:  bending mode, torsion mode, and shell mode.  The specification conceded that prior art methods existed to reduce each of these vibration modes.  In particular, it was known in the field to use “liners” for this purpose.  “Liners” are hollow tubes made of fibrous material (such as cardboard) with outer resilient members that frictionally engage the inner diameter of the propshaft.  Prior art methods would insert liners in a propshaft and thereby dampen (i.e., reduce or attenuate) the vibration of the propshaft. 

Although the ’911 patent acknowledged that liners had been used in the past to attenuate each type of vibration mode individually, the inventors contended that none of the prior art methods reduced two vibration modes simultaneously.  The alleged innovation of the ’911 patent was the ability to use liners to damp two vibration modes – the bending and shell modes – simultaneously.   

The Federal Circuit treated independent claims 1 and 22 of the ’911 patent as representative of the asserted claims.  Claim 1 states:

1.  A method for manufacturing a shaft assembly of a driveline system, the driveline system further including a first driveline component and a second driveline component, the shaft assembly being adapted to transmit torque between the first driveline component and the second driveline component, the method comprising:

providing a hollow shaft member; 

tuning at least one liner to attenuate at least two types of vibration transmitted through the shaft member; and 

positioning the at least one liner within the shaft member such that the at least one liner is configured to damp shell mode vibrations in the shaft member by an amount that is greater than or equal to about 2%, and the at least one liner is also configured to damp bending mode vibrations in the shaft member, the at least one liner being tuned to within about ±20% of a bending mode natural frequency of the shaft assembly as installed in the driveline system.

The first thing that leaps out regarding claim 1 of the ’911 patent is that it is not a software or e-commerce patent like those that the Federal Circuit frequently scrutinizes under the “abstract idea” exception to eligibility.  Rather, claim 1 lies in the domain of classical mechanical inventions.  Accordingly, the majority (consisting of Judges Dyk and Taranto) did not rely on the abstract idea exception to hold the claims invalid. 

The majority instead analyzed the claims under the “law of nature” exception.  Outside of the life sciences context – in particular, outside of claims directed to methods of treatment and methods of diagnosis – the courts have cited the “law of nature” exception much less frequently than the “abstract idea” exception.  But the Federal Circuit stated in American Axle that “[t]hat there is no legal principle that a claim to a method of manufacturing cannot be directed to a natural law, nor are there any cases saying so.”      

The natural law the ’911 claims implicated is Hooke’s law.  According to the majority, “Hooke’s law is a natural law that mathematically relates the mass and/or stiffness of an object to the frequency with which that object oscillates (vibrates).”  Witnesses from both sides “agree[d] that Hooke’s law undergirds the design of a liner so that it exhibits a desired damping frequency pursuant to the claimed invention.”      

American Axle acknowledged that “the selection of frequencies for the liners to damp the vibrations of the propshaft at least in part involves an application of Hooke’s law,” but argued that its claims are not merely directed to Hooke’s law.  American Axle emphasized that the process of tuning a liner is complicated, for a liner “is a complex distributed object with different stiffnesses in different directions … that depend on the location of the applied force and the measured displacement.”  American Axle asserted that the process of tuning a liner might involve extensive computer modelling and experimental modal analysis, not just a straightforward application of Hooke’s law. 

The problem for American Axle, which the majority stated repeatedly, was that the claims did not include any details about the computer modeling or modal analysis – or any other “steps for achieving the claimed result of damping two different types of vibrations.”  According to the majority, the claims “simply instruct the reader to tune the liner – a process that [ ] merely amounts to an application of a natural law (Hooke’s law) to a complex system without the benefit of instructions on how to do so.”  The majority explained that this does not suffice, for when a claim recites just a result, and not the means for how to accomplish the result, the claim “runs headlong into the very problem repeatedly identified by the Supreme Court in its cases shaping [the] eligibility analysis:” i.e., that “a patent is not good for an effect, or the result of a certain process, as that would prohibit all other persons from making the same thing by any means whatsoever.”  Le Roy v. Tatham, 55 U.S. (14 How.) 156, 174-75 (1853).   

The patent’s specification did not help American Axle either.  The majority said that the specification “recite[d] only a nonexclusive list of variables that can be altered to change the frequencies exhibited by a liner,” not any of the computer modeling or modal analysis that American Axle touted in its appeal briefs.  The majority also pointed out that the specification “describe[d] tuning in terms of the result achieved, rather than the particular process by which the result is accomplished.”  Judge Dyk’s opinion made clear that even a more robust specification would not have altered his view of the ’911 patent.  The Supreme Court in O’Reilly v. Morse, 56 U.S. (15 How.) 62, 112-20 (1854), “established long ago that an inadequately concrete claim is not saved from ineligibility by the presence of adequate concrete recitations in the specification or in other claims.”  Nonetheless, the specification confirmed “that the concept of tuning embodied by the parent is merely results-oriented.”   

American Axle is not the first time that the Federal Circuit has held claims invalid under Section 101 for a failure to recite how to accomplish the claimed result or effect.  A line of other recent post-Alice decisions also turns on this issue.  See, e.g., Innovation Scis., LLC v. Amazon.com Inc., 2019 U.S. App. LEXIS 19753, *8 (Fed. Cir. July 2, 2019); Univ. of Fla. Research Found., Inc. v. GE Co., 916 F.3d 1363, 1368 (Fed. Cir. 2019); Interval Licensing LLC v. AOL, Inc., 896 F.3d 1335, 1345-46 (Fed. Cir. 2018); Two-Way Media Ltd v. Comcast Cable Communs., LLC, 874 F.3d 1329, 1337 (Fed. Cir. 2017); Elec. Power Group, LLC v. Alstom S.A., 830 F.3d 1350, 1351, 1355-56 (Fed. Cir. 2016).  But the majority opinion in American Axle expands on this rationale more than the Federal Circuit has done in the past. 

In response to an argument raised by Judge Moore in her dissent, the majority also explains that “the failure of the claims to designate how to achieve the desired result” is not “exclusively an issue of enablement.”  According to the majority, “[e]nablement is concerned with whether the ‘specification of a patent [ ] teach[es] those skilled in the art how to make and use the full scope of the claimed invention.’”  By contrast, “Section 101 is concerned with whether the claims at issue recite a natural law, not whether the specification has adequately described how to make and use the concretely claimed structures and steps.”

As noted, Judge Moore dissented.  Her stinging fourteen-page dissent attacks the majority opinion on several fronts.  Most significantly, Judge Moore asserted that the majority ignored step two of the Alice/Mayo test by reducing the Section 101 inquiry down to the first step alone, and improperly conflated Section 101 with Section 112’s separate enablement requirement.  Judge Moore also accused the majority of “repeated[ly] misrepresent[ing] [ ] the record, in each instance to the patentee’s detriment[.]”  This disturbed Judge Moore especially because the court was supposed “to be applying the summary judgment standard” by resolving factual disputes in the patentee’s favor.

The final paragraph of Judge Moore’s dissent captures how vehemently she disagreed with the majority in this case.  It is worth reading:

Today, the majority concludes that the ’911 patent claims are not eligible because they do not teach a skilled artisan how to tune a liner.  The majority holds that they are directed to some unarticulated number of possible natural laws apparently smushed together and thus ineligible under § 101.  The majority concludes that the inventive concepts ‘make no difference.’  Section 101 simply should not be this sweeping and this manipulatable.  It should not be used to invalidate claims under standards identical to those clearly articulated in other statutory sections, but not argued by the parties.  It should not subsume § 112.  It should not convert traditional questions of fact (like undue experimentation) into legal ones.  The majority’s validity goulash is troubling and inconsistent with the patent statute and precedent.  The majority worries about result-oriented claiming; I am worried about result-oriented judicial action.  I dissent.

A petition for en banc review of this decision remains pending. 

In light of American Axle and the cases it cites, patent prosecutors should carefully consider whether claims they are seeking are too results-oriented.  The failure to describe in a claim how to achieve the desired result can doom a claim under Section 101.

Authors: Larry Gabuzda  and  Marc J. Pernick