Rough Ride for Split Federal Circuit on Eligibility of Driveshaft Vibration Reduction Method

Sharply differing majority and dissenting opinions in the Federal Circuit’s recent American Axle & Manufacturing v. Neapco Holdings decision present yet another case where the Federal Circuit appears to be in need of further patent eligibility guidance from the Supreme Court. The American Axle case centers on the patent-eligibility of a method for dampening vibrations in vehicle driveshafts. In its recent decision, the Federal Circuit upheld the district court’s grant of summary judgment in that dispute, holding that under controlling precedent the asserted claims are ineligible under § 101 as preempting a natural law.

The Majority Opinion: Patent Claims Ineligible Under § 101

Judge Dyk, writing for the majority, began with a fairly detailed discussion of the 7,774,911 patent that was at issue. He characterized the patent as relating “to a method for manufacturing driveline propeller shafts (‘propshafts’) with liners that are designed to ‘attenuat[e] … vibrations transmitted through a shaft assembly.” He explained that per the patent, shafts are typically made of hollow tubes and the vibrations include three modes: “bending mode” caused by energy transmitted longitudinally along the shaft; “torsion mode” caused by tangential energy that twists the shaft; and “shell mode” based on a standing wave transmitted circumferentially about the shaft. Each mode causes vibrations at different frequencies. The prior art discussed in the patent attenuated vibrations by use of liners that are inserted inside the shaft tubes, as well as various other methods of dampening the vibrations such as weights and the like. He explained, again per the patent, that such mechanisms provide two types of attenuation: resistive attenuation, in which the mechanism deforms with the vibration to absorb the vibration energy, and reactive attenuation, in which the mechanism vibrates in opposition to the shaft’s vibration so as to cancel out at least a portion of the vibration energy.

With this background in hand, Judge Dyk turned to the patent claims. He stated that the district court treated claims 1 and 22 as representative of the 20 asserted claims.

  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.

* * *

  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 a mass and a stiffness of at least one liner, and

inserting the at least one liner into the shaft member;

wherein the at least one liner is a tuned resistive absorber for attenuating shell mode vibrations and wherein the at least one liner is a tuned reactive absorber for attenuating bending mode vibrations.

With such claim language in mind, he noted that the patent admitted that mechanisms were known to attenuate bending, shell, and torsion vibration modes, “[b]ut these prior art damping methods were assertedly not suitable for attenuating two vibration modes simultaneously.” He noted that the patent owner AAM urged that it had come up with the concept of “tuning” a liner to dampen multiple modes simultaneously, but he found that “[n]either the claims nor the specification describes how to achieve such tuning.” Judge Dyk quoted the district court’s conclusion that “the Asserted Claims as a whole are directed to laws of nature: Hooke’s law and friction damping” and paraphrased its further conclusion that the claims “amounted to merely ‘instruct[ing] one to apply Hooke’s law to achieve the desired result of attenuating certain vibration modes and frequencies’ without ‘provid[ing] [a] particular means of how to craft the liner and propshaft in order to do so.”

Moving on to the Federal Circuit’s de novo analysis, the majority largely agreed with the district court’s approach. Judge Dyk began the analysis by stating that “[t]here 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.” He noted, based on the specification of the ‘911 patent, that most aspects of it were well known in the art, and that AAM did not dispute this, nor did it dispute that selection of frequencies for damping “at least in part involves an application of Hooke’s law,” which mathematically relates mass and stiffness of an object to its oscillation frequency. Judge Dyk faulted the claims for not describing any specific method for applying Hooke’s law but instead merely stating “that the liner should be tuned to dampen certain vibrations.” This, he said, “essentially amounts to the sort of directive prohibited by the Supreme Court in Mayo—i.e. ‘simply stat[ing] a law of nature while adding the words “apply it.”’”

Judge Dyk proceeded to discuss Supreme Court caselaw including Mayo, Flook, Diehr and the other cases now very familiar to modern § 101 analysis, distinguishing those where specific and detailed steps were claimed from those with broader language. He concluded that “[t]he claims here simply instruct the reader to tune the liner—a process that, as explained above, 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.” Addressing AAM’s argument that the situation is more complex than “just a bare application of Hooke’s law,” he said that “[w]hat is missing is any physical structure or steps for achieving the claimed result of damping two different types of vibrations.”

Completing the analysis, Judge Dyk found nothing in the other steps of the claims to be more than conventional pre- and post-solution activity, and further determined that AAM waived any argument that “the dependent claims change the outcome of the eligibility analysis.”

The Dissenting Opinion: Judge Moore "deeply troubled"

Judge Moore minced no words in her dissent. She began by stating, “The majority’s decision expands § 101 well beyond its statutory gate-keeping function and the role of this appellate court well beyond its authority.” After asserting that the majority essentially reduced the two-part Mayo test to a single inquiry, she said, “I am deeply troubled by the majority’s disregard for the second part of the Alice/Mayo test, its fact finding on appeal and its repeated misrepresentation of the record, in each instance to the patentee’s detriment; all when we are to be applying the summary judgment standard no less.”

She also asserted that the majority seemed untroubled by the repeated recognition that the claims may be directed to natural laws other than Hooke’s law. “Section 101 is monstrous enough, it cannot be that now you need not even identify the precise natural law which the claims are purportedly directed to.”

Judge Moore wrote extensively about the dependent claims and how they impact the § 101 analysis, stating that AAM did in fact argue that they “further narrow the physical characteristics of the liners to be used and their positioning within the drive shaft.” This, she said, was critical to the analysis:

I do not see how these claims are directed to a natural law. And even if part one of the Alice/Mayo test was satisfied here, there is a part two. The claims will not be held ineligible (remember § 101 is meant to be a gatekeeper) if the claims contain an “inventive concept.” There are many here, articulated in the claims themselves, about which there exist at least questions of fact which should have precluded summary judgment. Argued below, and throughout the briefing on appeal and during oral argument to this panel, the patentee maintains that liners had never before been used to reduce bending mode vibration.

In a footnote, she recited three separate ways in which she thought the majority improperly ignored the dependent claims and why AAM had neither agreed to use of representative claims nor waived its rights regarding dependent claims. She concluded on this point: “It is inappropriate in light of these facts for the majority to sua sponte declare the claims representative and ignore the expressly argued dependent claims and limitations.”

Returning to part two of the Alice/Mayo test, after quoting the majority’s statements regarding the relevant prior art on liners and that AAM did not dispute that such features were known, Judge Moore said, “These statements are false.” Using several record citations to back up this assertion (including one in which counsel for AAM corrected a member of the majority at oral argument when he tried to suggest that a certain feature was known in the prior art) she again bluntly stated, “It matters not at all to the majority that the patentee alleges that liners had not been used to reduce bending mode vibration, and that Neapco presented no evidence to contradict that. The majority has decided to make its own fact finding that prior art liners had been used.”

Judge Moore closed this analysis by concluding that there was no evidence of record regarding such prior use of liners for bending mode vibration damping and that AAM had argued throughout that this was an inventive concept present in every claim of the patent.

Ultimately the majority says the inventive concept “makes no difference to the section 101 analysis.” Maj. at 13. I understand this to be an outright rejection of the second step of the Alice/Mayo test. The majority explains: 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 claims structures and septs.” Maj. at 21. This statement of law is just plain wrong.”

Thereafter, Judge Moore discussed additional inventive concepts she found in claim limitations that “get progressively more detailed about the structure and positioning of the liner inside the drive shaft.” On this point, she stated, “It is remarkable that the majority thinks that claims with all of these very physical, very concrete, very structural limitations are nonetheless ‘missing any physical structure or steps.’”

Before concluding, Judge Moore tried to explain what she thought was driving the majority’s viewpoint: the fact that the patentee has not claimed precisely how to tune a liner to dampen the multiple modes of vibration. She cited nearly a dozen examples from the record on this point, and then from those examples explained why they properly relate not to the claims but to the specification, and are “exactly and precisely” what is addressed by the enablement test of § 112. Her conclusion on this point was again direct. “To be clear, according to the majority, even if these claims are enabled, they are still ineligible because the claims themselves didn’t teach how. This is now the law of § 101. The hydra has grown another head.”

In the majority opinion, Judge Dyk countered Judge Moore’s § 112 perspective in some detail:

The dissent suggests that the failure of the claims to designate how to achieve the desired result is exclusively an issue of enablement. Dissent Op. at 2, 11–14. Both the Supreme Court cases and our cases addressing section 101 have held otherwise, as the earlier discussion demonstrates. Enablement is concerned with whether the “the specification of a patent… teach[es] those skilled in the art how to make and use the full scope of the claimed invention.” In re Wright, 999 F.2d 1557, 1561 (Fed. Cir. 1993). 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. The Supreme Court in Mayo made clear that section 101 serves a different function than enablement. Mayo, 566 U.S. at 90 (“[T]o shift the patent-eligibility inquiry entirely to these later [statutory] sections risks creating significantly greater legal uncertainty, while assuming that those sections can do work that they are not equipped to do.”). Moreover, even if, as the dissent says, the specification gives one adequately concrete embodiment, which we need not decide, that is not enough: O’Reilly 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. 56 U.S. at 112–20 (holding eighth claim ineligible while upholding first seven claims).

Returning to the dissent, Judge Moore tied all her points together in a final paragraph, concluding, “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.”

Congressional & Patent Community Response

Unsurprisingly, the sharply different views between the majority and dissent in American Axle quickly generated commentary. The day after the decision, Representative Doug Collins of Georgia issued a press release with this statement regarding the decision:

Our patent eligibility test is clearly flawed, and the court’s decision yesterday regarding American Axle & Manufacturing, Inc. showcases the inadequacies of this test. It’s unthinkable the courts found this invention, a manufacturing process for making a key automotive part, as patent ineligible. The courts have misstated the law several times, which deprives many innovative products of adequate protection. Congress must establish a new eligibility test to encourage investment in developing new U.S. technologies and ensure American inventors aren’t at a global disadvantage. I’ve been working on reforming this test with my colleagues in both the House and the Senate, and I look forward to continuing this important work.

Representative Collins was one of the legislators who worked earlier this year on amending § 101 as we reported previously. In view of the very diverse testimony on the proposed amendments, which we also summarized, it is perhaps not surprising that a revised draft has not yet been circulated. Hopefully, the two very distinct perspectives provided by the majority and dissent in American Axle will help the development of further perspectives on what, if anything, is to be done next.

*The perspectives expressed in the Bilski Blog, as well as in various sources cited therein from time to time, are those of the respective authors and do not necessarily represent the views of Fenwick & West LLP or its clients.