Claims Directed to Attenuating Driveline Vibrations Fall Victim to Law of Nature Challenge
In a striking recent decision from the U.S. District Court for the District of Delaware, claims of a vibration attenuation patent were deemed patent ineligible as being directed to laws of nature under 35 U.S.C. § 101 -- namely, both Hooke's law and friction damping.
The Plaintiff, American Axle & Manufacturing, Inc. (AAM), charged Neapco with infringement of three of its patents. The parties filed cross-motions for summary judgment on the issue of patent eligibility under § 101 with regard to one of those patents: U.S. Patent No. 7,774,911 (the '911 patent), entitled "Method for attenuating driveline vibrations." The District Court, addressing both motions together, granted Neapco's motion.
As the title reflects, the claimed invention involves reducing vibrations transmitted through a shaft assembly of a driveline (e.g., a drivetrain of a motor vehicle), and each independent claim recites "[a] method for manufacturing" such an assembly. Examples of such vibrations include (i) bending mode vibration, which transmits energy longitudinally along the shaft and causes the shaft to bend, (ii) torsion mode vibration, which transmits energy tangentially through the shaft and causes the shaft to twist, and (iii) shell mode vibration, which transmits a standing wave circumferentially around the shaft and causes the cross-section of the shaft to deflect or bend. The '911 patent states a need in the art for a method of damping these vibrations, as they can result in tonal noise that can be heard by occupants in a vehicle. The invention thus aims to serve as the desired improvement with regard to shell mode vibrations, and also to one or both of bending mode vibrations and shell mode vibrations.
To address these vibrations, the '911 patent proposes tuning the mass and stiffness of at least one liner included in the shaft assembly. Such a liner -- which could be made of cardboard, fiberglass, carbon fiber, metal, and/or other materials, and can include both a "structural portion" and "resilient member(s)" -- is sized so that, when the liner is inserted into a hollow shaft member, the liner frictionally engages the inner diameter of the shaft member. The liner(s) can then be tuned in a way that causes the liner(s) to act as a tuned resistive absorber for attenuating bending mode vibrations, and also causes the liner(s) to act as a tuned reactive absorber for attenuating bending mode and/or torsion mode vibrations.
As a representative example of the asserted claims, claim 22 is reproduced below:
22. 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.
Reviewing the cross-motions for summary judgment, the District Court applied the two-step Alice test for determining eligibility of the claims.
Regarding step 1, the laws of nature at issue were Hooke's law and friction damping. AAM did not dispute the definition of Hooke's law (F = kx), particularly, that the force (F) needed to extend or compress a spring having stiffness (k) is linearly related to a displacement (x) of the spring. Nor did AAM dispute that the frequency of vibration of an object is affected by changes in mass or stiffness of the object. And AAM's expert stated that friction damping "is a property of physics experienced by any two surfaces in contact."
Given this, Neapco insisted -- and the District Court agreed -- that, in order to tune the liner(s) as recited in the asserted claims, one only needs to apply Hooke's law, adjust the mass and stiffness of the liner(s), and then measure how much damping results to the frequency of vibration. As one might expect, AAM argued in response that the asserted claims are not directed to a law of nature, but rather to an industrial process for manufacturing parts of a motor vehicle. But the District Court was not convinced, and concluded that, when considered as a whole, the asserted claims "are applications of Hooke's law with the result of friction damping," and "fail to instruct how to design the tuned liners or manufacture the driveline system to attenuate vibrations."
While these principles of physics are of course well-known, it is troubling here that this conclusion does not appear to give proper consideration to what the asserted claims are "directed to" in accordance with § 101. Viewed as a whole, the claims do not appear to risk preempting others from using Hooke's law and friction damping, and AAM does not appear to be attempting to patent these principles. On the other hand, it would seem overly optimistic to assume that the presence of various driveline components would side against preemption and elevate the claims as a whole to a level of patent eligibility.
But as we've seen before from other courts, the District Court's analysis obfuscates the considerations needed to determine whether claims survive step 1 and the Alice framework as a whole. The District Court addressed the issue of preemption in a section separate from step 1 and, in line with the Federal Circuit's view in Ariosa, deemed the issue to be moot based on the conclusion that the claims only disclose patent ineligible subject matter. And despite concluding at step 1 that the claims are "applications" of known laws of nature, the District Court reached the ultimate conclusion under § 101 that the claims are "directed to" those laws of nature.
Turning to step 2, the District Court began by setting out the groundwork laid by the past decisions in Diehr, Mayo, Flook, and Ariosa. The District Court was then quick to note the recent Federal Circuit standard in Berkheimer v. HP Inc. (Fed. Cir. 2018) -- namely, that the patent eligibility inquiry, which is a question of law, may also involve issues of fact, and that a factual dispute regarding whether the invention describes well-understood, routine, and conventional activities can preclude summary judgment on the issue of § 101. Building off this point, the District Court went on to state, in a conclusory fashion:
But here the record reveals no genuine disputes of material fact. The parties here do not dispute that the non-tuning claim limitations are well-understood, routine, and conventional. Nor is there any genuine dispute of material fact that the tuning limitations are non-inventive applications of Hooke's law. Thus, "this issue can be decided on summary judgment as a matter of law." [citation omitted]
In an attempt to distinguish from Mayo, AAM asserted that two of the elements recited in its claim are new and inventive. The District Court was not convinced.
The first of these elements is the concept of tuning the mass and stiffness of a liner, which was construed as "controlling a mass and stiffness . . . to configure the liner to match a relevant frequency or frequencies." AAM insisted that nowhere in the prior art were there attempts to tune liners in drive shafts to target certain frequencies/modes in the way this element suggests, but the District Court agreed with Neapco that controlling these liner characteristics amounted to nothing more than an inherent design choice of applying Hooke's law.
The second element AAM argued to be inventive is the concept of having the liner(s) tuned specifically to target shell mode and bending mode vibrations. The District Court dismissed this argument as well, stating that this element merely recites "the result that is achieved from performing the method rather than an active step in the method." (However, the remainder of the District Court's reasoning under the Alice test suggests that it would have struck down the claims regardless of whether such an active step was present.)
The District Court went on to again refer to the "non-tuning" claim limitations (i.e., inserting liners into propshafts) in comparing the asserted claims with Mayo:
In sum, as in Mayo, 566 U.S. at 79-80, the Asserted Claims "inform a relevant audience [NVH engineers] about certain laws of nature [Hooke's law and friction damping]; any additional steps consist of well-understood, routine, conventional activity already engaged in by the scientific community [inserting liners with certain characteristics into propshafts to attenuate driveline vibrations]; and those steps, when viewed as a whole, add nothing significant beyond the sum of their parts taken separately [having the same, but potentially slightly improved, effect of attenuating certain frequencies and modes of driveline vibrations]." Hence, as in Mayo, the Asserted Claims here are not patent-eligible.
The District Court then wrapped up its step 2 discussion with reasoning reminiscent of its reasoning under step 1. In particular, the District Court agreed with Neapco that the claims did not include any discrete liner or shaft design, and instead merely instruct one to apply the laws of physics to solve a problem.
Before stating its final conclusion, the District Court in two short sections quickly addressed preemption as stated above and dismissed the notion that the claims were eligible under the machine-or-transformation test.
The asserted claims may have been problematic and susceptible to failure, but not necessarily for the reasons stated by the District Court. Notwithstanding the question of whether these claims should have survived USPTO examination under 35 U.S.C. § 103, the District Court's analysis here is more of the same line-blurring between § 101 and § 103 that has seemingly become commonplace, yet it suggests that the Berkheimer panel might have been on to something. Courts continue to muddy the considerations required under the Alice test. In any event, the decision here further demonstrates the proclivity by courts to rely on § 101 to strike down claims. In addition, this decision is also a post-Berkheimer example of how patents can be invalidated at the summary judgment stage.
American Axle & Manufacturing, Inc. v. Neapco Holdings LLC (D. Del. 2018)
Memorandum Opinion by District Judge Stark
