US 9574972

I'll search for authoritative records on US 9574972 and any associated litigation.

Let me check specifically for litigation/docket records and USPTO status.

US Patent 9,574,972 — Analyst Summary

Search scope note: I searched for the exact identifier "9574972" / "US9574972B2" / "9,574,972" against patent databases (Google Patents, FreePatentsOnline, Justia) and for docket/litigation records. I found no court records — including none in the Federal Circuit or any 2026 docket — naming this specific patent. Results for similar numbers (e.g., U.S. 8,424,972 Wirtgen/Caterpillar; U.S. 9,967,389 ProudLion/Amazon; MITII v. OpenAI discussing a different "′972 patent") are different patents and were excluded. I cannot state with certainty that no case exists; only that I found no authoritative record of one. Treat any litigation conclusion as unverified.

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Bibliographic data (from Google Patents / FPO, consistent across sources)

⚠️ Date discrepancy: your prompt states the current date is April 26, 2026, while the system context says September 29, 2026. The status events above (lapse effective Feb. 2025, docket items dated mid-2026) are only consistent if the later date is correct. Please confirm which date governs for your purposes.

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Abstract (verbatim)

"Methods and systems are provided for evaluating a steering system of a vehicle, in which the steering system includes a steering column, steering rack, and pinion. The rack is manipulated as the steering system is mounted to a testing system. The steering column is also manipulated as the steering system is mounted to the testing system. Data is collected from the manipulating of the rack and the dithering of the steering column for use in evaluating the steering system."

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Plain-language overview of the disclosure

The patent covers bench testing of a steering gear before it is installed in a vehicle. A steering assembly (steering-wheel-representative mass, column, rack, control pinion, assist pinion, optional electric motor) is mounted to a rigid test stand. A rack actuator shakes/excites the rack (sinusoidal force, 5–30 Hz in 1 Hz dwell steps, ~16 s per dwell, optionally with sweep/chirp or dither), while a steering-input actuator simultaneously dithers the column/steering-wheel mass through a torsion spring (triangular displacement, ±10°, ~16 s period). Up to six channels are recorded: rack force (Fr), rack lateral acceleration (Ar), rack-housing acceleration (Ah), two steering-wheel tangential accelerations 180° apart (Asw1, Asw2), and optionally EPS motor speed (Vm).

The signals are DC-offset-removed; steering-wheel angular acceleration is computed as AAsw = (Asw1 + Asw2)/D, where D is the accelerometer separation. Data is segmented into constant-frequency blocks, band-pass filtered ±0.5 Hz around the drive frequency (found by FFT of the cleanest channel, rack force), transients trimmed, and a 1-second window is taken around the peak angular-acceleration time — the instant the inventors treat as when static friction breaks. FFTs on that window yield complex ratios that convert to five diagnostic metrics: gear sensitivity, gear ratio, gear stiffness, gear impedance, and motor ratio. A steering system is judged healthy if gear sensitivity and gear ratio are below thresholds and gear stiffness and gear impedance are above thresholds.

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Independent claims — plain-language summaries

Claim 1 — Method (invalidity/patentability notes: this is the "core" method claim)
A method of evaluating a vehicle steering system (defined as including a steering column, steering wheel mass, steering rack, and pinion) using a testing system, comprising four steps:

1. manipulating the rack on the testing system;
2. manipulating the steering column on the testing system;
3. collecting data while both are manipulated, wherein collecting data includes measuring an acceleration of steering when the column is manipulated; and
4. calculating a value pertaining to the steering system from that data, the value being one of gear sensitivity, gear stiffness, gear impedance, or motor ratio.

Note: the claim recites a closed Markush-style group ("selected from the group consisting of") of four values — notably gear ratio is excluded and is instead covered only by dependent claim 9.

Claim 11 — Method (windowed/peak-based variant)
A method (steering system = steering column, steering rack, pinion — note: no "steering wheel mass" element in this claim's preamble) comprising:

1. manipulating the rack;
2. manipulating the steering column;
3. collecting data while both are manipulated;
4. determining a maximum angular acceleration time for the data; and
5. calculating a value pertaining to the steering system using only the portion of data in a window corresponding to that maximum angular acceleration time.

Note: claim 11 does not itself limit the "value" to any enumerated set; that limitation appears in dependent claim 14 (gear stiffness, gear impedance, gear sensitivity, motor ratio).

Claim 15 — System
A system for evaluating a steering unit (defined as including steering column, steering wheel mass, steering rack, pinion), comprising:

• a first actuator configured to manipulate the rack on the system;
• a second actuator configured to manipulate the steering column on the system;
• a sensor unit configured to obtain data while the rack and column are manipulated, wherein the data comprises a measured acceleration of steering when the column is manipulated; and
• a processor coupled to the sensor unit, configured to calculate from the data one or more of: gear stiffness, gear impedance, gear sensitivity, and motor ratio.

Note: claim 15 uses "one or more of" (open-ended, conjunctive-ambiguous phrasing) rather than the closed group used in claim 1.

Dependent claims in brief: 2 (dither the steering wheel mass via actuator); 3 (measure rack force); 4 (measure rack acceleration); 5 (measure steering angle); 6–8, 10 (calculate gear sensitivity / stiffness / impedance / motor ratio respectively); 9 (calculate gear ratio); 12–13 (measuring rack force & rack acceleration; steering-wheel-mass acceleration & steering angle); 16–18 (sensor unit = force sensor + rack accelerometer; dithering by second actuator; steering-wheel-mass accelerometer + steering-angle sensor); 19 (processor configured to calculate motor ratio).

Coverage gap worth flagging: the Summary of the Invention describes a third statutory class — a program product on a non-transitory computer-readable medium — but no program-product claim appears in the issued 19 claims. Issued claim coverage is methods plus a system.

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Prior art cited (selected, from the 22 patent citations listed)

Toyota DE 19622687 A1 and US 5,700,951 (steering-system test beds); Schenck Pegasus US 4,672,844; TRW US 5,880,381; Navistar US 5,605,853; GM's own DE 10 2006 016 764 A1 and US 2009/0204343 A1 (steering rack rattle test procedure) and US 2010/0031739 A1 (measuring torsional dynamics of a steering column at small dynamic amplitudes) and US 2012/0150389 A1 (EPS with improved road feel). Non-patent citation: Qatu, Llewellyn & Spadafora, Experimental Mechanics (2001) 41:151.

Notable forward citations include GM's US 9,885,638 B2 (determining steering performance, 2018), US 9,604,665 B2 / 9,669,867 B2 / 9,950,736 B2 (stiction and stick-slip characterization, 2017–2018), and US 11,623,683 B2 (vehicle power steering test system control, 2023).

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Explicit uncertainties

1. No litigation found. I could not locate any district court, ITC, PTAB, or Federal Circuit proceeding identifying US 9,574,972. I cannot verify the absence of such a case — only that my searches returned none. If you need a definitive answer, a paid docket service (Docket Navigator, Lex Machina, PACER/RECAP) queried on the exact string is required.
2. Examiner/agent fields come from FreePatentsOnline only; I did not independently confirm them at USPTO PatentCenter.
3. Maintenance-fee exhaustion is reported by Google Patents' automated legal-events feed (lapse effective 2025-02-21). This is a data-derived status, not a legal conclusion; reinstatement petitions under 37 CFR 1.378 could theoretically alter it, and I found no record of one.
4. The "expires 2033-06-11" figure in the Google Patents header reflects an adjusted term calculation (extension/terminal-disclaimer adjustments) that I have not recomputed from the face of the patent.

Sources: https://patents.google.com/patent/US9574972B2/en ; https://www.freepatentsonline.com/9574972.html ; https://patents.justia.com/patent/9574972

I'll search for litigation involving US patent 9574972.

Let me search more targeted litigation databases.

Let me try a few more targeted searches to confirm.

Litigation Search Report — U.S. Patent No. 9,574,972

Bottom line

I found no known litigation involving U.S. Patent No. 9,574,972. No district court action, ITC Section 337 investigation, PTAB post-grant proceeding (IPR/PGR/CBM), or Federal Circuit appeal asserting or challenging this specific patent was identified in my searches.

What was searched

I ran targeted queries against patent-litigation-oriented sources and general web indexes, including terms pairing the exact patent number with litigation keywords:

• US patent 9574972 litigation
• "9574972" patent lawsuit defendant
• portal.unifiedpatents.com litigation 9574972
• RPX Insight "9574972" OR "9,574,972" patent litigation defendant
• "9,574,972" patent infringement complaint
• GM Global Technology Operations patent 9574972 asserted lawsuit steering

All hits fell into non-litigation categories:

Important cautions

1. No auto-correction applied. Every reference to "9574972" that surfaced was matched literally. I did not treat shorthand references such as "the '957 patent" as this patent — in patent practice that notation typically denotes a different patent whose number ends in 957 (e.g., in the D.N.J. ANDA litigation it refers to a pharmaceutical patent, plainly not this GM steering-test patent).
2. Access limitations. I could not directly query PACER, Docket Navigator, or the Unified Patents portal case list (several of these sit behind subscription/authentication walls and a couple of my follow-up queries were cut off). Absence of results in the sources reachable to me is not conclusive proof that no litigation exists. A definitive negative clearance would require a direct PACER docket search and a Docket Navigator / Unified Patents / RPX query.
3. No post-grant proceedings found. I also saw no PTAB petition (IPR/PGR/CBM), no reexamination, and no Federal Circuit docket tied to this number.

Context that bears on litigation likelihood

• Owner: GM Global Technology Operations LLC (original and current assignee). This is a GM-internal test-methodology patent, not a patent held by a non-practicing entity with a history of assertion.
• Subject matter: Method/system for bench-testing a vehicle steering system on a test stand (mounting the system, exciting the rack and dithering the steering column, and computing "gear sensitivity," "gear ratio," "gear stiffness," "gear impedance," and "motor ratio"). Such a manufacturing/engineering-process patent is generally a defensive/QA asset rather than a licensing or assertion tool.
• Status: The register shows the patent expired for failure to pay maintenance fees — lapse effective February 21, 2025 ("Patent expired for failure to pay maintenance fees," 37 CFR 1.362), with the last maintenance-fee payment recorded as the 4th year (August 6, 2020). An expired patent is not a plausible candidate for assertion, further supporting the absence of litigation.
• Foreign counterparts (KR 101314087B1, DE 102011089950B4, CN 102589906B) are all listed as expired/fee-related as well.

Recommendation

If you need a court-admissible negative finding, I would run the number directly through:

• PACER / CourtListener RECAP (all district courts, with "9,574,972" as the search string),
• Unified Patents Portal (https://portal.unifiedpatents.com/litigation/caselist) and its PTAB case list,
• RPX Insight / Docket Navigator, and
• USPTO PTAB and CAFC dockets.

Based on everything reachable in this search, however, the answer is: no litigation is known for U.S. Patent No. 9,574,972.

Proceedings overview

Total AIA trial proceedings on file for US 9,574,972: 0. The USPTO Open Data Portal returns no IPR, PGR, or CBM proceeding for this patent, and targeted web searches (Google Patents litigation/PTAB tabs, PTAB E2E/PTAB-API, Federal Circuit and CourtListener dockets, and general petitioner-side queries naming GM as patent owner) surfaced no petition, no institution decision, no Final Written Decision, and no appeal referencing the '972 patent. Because the count is zero, there is no breakdown by status to report — nothing is active, nothing has been invalidated, nothing has been settled, and nothing has been denied institution.

The bottom-line defensive posture is therefore unusual and, for a defendant, favorable on grounds unrelated to PTAB: the patent has never been stress-tested at the Board, so there is no estoppel, no FWD, and no claim-level invalidity finding to hand you — but the patent is also expired for failure to pay maintenance fees as of 2025-03-31 (lapse effective 2025-02-21), having been "Expired - Fee Related." An expired patent cannot be infringed prospectively, and the damages window is closed and historical. That is a far stronger defense than any IPR outcome would have given you.

There are no per-proceeding sections to write. The remainder of this memo addresses what the absence of proceedings means and how you should use it.

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Strategic summary

Claim status: all 19 claims are UNTESTED at the PTAB, and all are subject to an expired patent. Claims 1–10 (method claims drawn to manipulating the rack and steering column, collecting data, and calculating gear sensitivity/stiffness/impedance/motor ratio), claims 11–14 (method claims adding the maximum-angular-acceleration-time windowing step), and claims 15–19 (system claims with first/second actuators, a sensor unit, and a processor) have never been construed or adjudicated by the Board. No claim has been canceled, and no claim has been confirmed. Any statement that "claims 1–5 were canceled" or that "the patent survived two IPRs" would be fabricated — neither happened.

Estoppel landscape: none. Because no IPR/PGR was ever instituted, § 315(e)(2) estoppel has never attached against anyone. A defendant today faces no estoppel bar whatsoever and is free to raise any § 102/§ 103 ground, in any forum, without the "raised or reasonably could have raised" restriction. Conversely, there is no petitioner-side roadmap (no institution decision, no FWD claim construction, no Board obviousness analysis) to borrow from. You would be building the invalidity case from scratch. The good news is that the file history gives you material: the examiner cited a substantial prior-art set (e.g., DE 19622687 A1 (Toyota), "Test bed for vehicle steering system"; US 4,672,844 (Schenck Pegasus); US 5,884,381 (TRW); US 5,700,951 (Toyota); CN 101696908 A; and GM's own US 2009/0204343 A1 on rack rattle testing), and the non-patent literature includes Qatu, Llewellyn & Spadafora, Experimental Mechanics 41:151 (2001) — a paper on steering-system dynamic measurement that is a natural obviousness anchor for a "manipulate both ends and measure" testing claim. Note also the narrowness of the claimed subject matter: claim 1 recites a test method, which raises a serious § 101/§ 271(g)-type question about whether a party performing a bench test can even be an infringer, and claim 15's "system" is essentially a test rig.

Pattern signals: essentially none. This is not a troll patent or a serial-IPR target. The assignee is GM Global Technology Operations LLC — an original-equipment manufacturer, not a monetization entity — and there is no defensive aggregator (Unified Patents or similar) anywhere in the chain; the Unified Patents portal hits for GM steering patents (e.g., CN-111114615-B, EP-1559630-A2) are unrelated automotive mapping entries, not challenges to the '972 patent. GM's active PTAB/enforcement footprint (e.g., the LKQ design-patent campaign over D797,625, D818,406, and D828,256, litigated in N.D. Ill. and appealed to the Federal Circuit) involves design patents for exterior body parts and is entirely unconnected to this utility patent. No petitioner has filed multiple IPRs here; no PTAB appeal exists to map. The patent appears to have been maintained passively and then allowed to lapse in 2025, which strongly suggests GM placed no current commercial value on it.

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Recommended next steps

• Lead with the fee lapse, not the PTAB. There is no FWD to link to or quote — do not invent one. The dispositive facts are in the patent's own legal-events record: maintenance-fee reminder mailed 2024-10-14, lapse for nonpayment 2025-03-31, and "PATENT EXPIRED FOR FAILURE TO PAY MAINTENANCE FEES" effective 2025-02-21 (source: Google Patents legal events for US9574972B2). Under 35 U.S.C. § 41 and the expiration-of-rights rules, an expired patent's claims cannot be enforced for post-expiration conduct, which squarely defeats a demand letter aimed at your current product.
• If a demand letter predates the lapse and targets past conduct, the PTAB is still a dead end (no proceedings exist to piggyback on), so the defense runs through district court invalidity — with the examiner-cited Toyota, Schenck Pegasus, and TRW references plus the Qatu Experimental Mechanics paper as the obviousness backbone — and through § 101/claim-scope arguments on what is, at bottom, a bench-test methodology.
• Confirm the lapse and any revival. Fee-related expiration can in principle be addressed by a petition to accept an unintentionally delayed payment. Pull the current fee/status record via USPTO Patent Center for US12/985,043 or PTAB E2E to confirm no revival petition or reinstatement is pending before you rely on the lapse as your primary defense.
• Monitor, but do not expect, PTAB activity. Because the patent is expired, an IPR is now statutorily unavailable as a practical matter (no live claims to amend and no injunctive value to the patent owner), so the probability of a new petition is near zero. Treat "no PTAB activity" as a settled fact, not an open question, and set the defensive strategy accordingly.
• Verify the litigation docket independently. I found no district-court or ITC assertion of the '972 patent, and no Federal Circuit appeal involving it, in the sources checked. If you have a case number from a demand letter, run it through CourtListener (courtlistener.com) to confirm whether the patent is in suit anywhere — that is the one open thread this analysis could not close.

Caveat on sources: the "0 proceedings" finding rests on the structured ODP block in the prompt plus web searches that surfaced no PTAB or Federal Circuit matter for this patent number. Absence of search hits is strong but not absolute proof of absence; a final confirmation via the PTAB E2E patent-number search linked above is advisable before relying on this in a filing.

I'll verify the assignment record and check for any assertion activity before drafting.

Assignment & Ownership Analysis — US 9,574,972 B2

Patent: US 9,574,972 B2 — Methods and systems for evaluating vehicle steering systems
App. No. 12/985,043 · Filed 2011-01-05 · Granted 2017-02-21 · Family: US20120173079A1, KR101314087B1, DE102011089950B4, CN102589906B

Sourcing note (read first): I could not query USPTO Assignment Center directly — the tool available to me returns search-engine index pages, not the live Assignment Center record set. The assignment data below is reconstructed from the Google Patents legal-events mirror of the USPTO assignment record (which reproduces reel/frame, conveyance type, execution date, recording date, assignors and free-format text) plus the front-page attorney-of-record data on FreePatentsOnline. Correspondent-of-record fields are not exposed in that mirror for this patent. Where I cannot retrieve a field, I say so rather than fill it in. Verification link: https://assignmentcenter.uspto.gov/ and legacy https://assignment.uspto.gov/patent/index.html — search patent number 9574972.

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Inventors

Pattern check — no adverse signal. All three inventors executed the assignment before filing (signing dates 2010-12-28 through 2011-01-03, application filed 2011-01-05), which is the textbook employee-assignment-before-filing sequence for a captive corporate R&D lab. There is no evidence of inventors departing GM within 12 months of filing, and Adams' continued patent output at GM indicates continuing employment rather than an exodus ahead of a portfolio sale. I found no evidence of an inventor-initiated or individual-ownership phase.

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Original assignee

GM Global Technology Operations LLC (Delaware LLC; 300 Renaissance Center, MC 482-C23-B21, Detroit, MI 48265; the "GTO" entity that received the bulk of General Motors' automotive technology under the Automotive Technology Assignment effective 2005-01-19).

• Named on the issued patent: Yes — "Current Assignee: GM Global Technology Operations LLC; Original Assignee: GM Global Technology Operations LLC."
• Primary line of business: Design, manufacture and sale of automobiles and light trucks; GM is a NYSE-listed operating company and the ultimate parent of the GTO IP-holding entity.
• Product embodying the claims: The patent claims a bench-test method and test system (rack actuator + steering-input actuator + accelerometers + FFT/ratio analysis producing gear stiffness, gear ratio, gear sensitivity, gear impedance and motor ratio). GM deployed this as an internal EPS steering-gear validation methodology for its electric power steering systems (the specification's HPS/EPS references and the CAN-bus link to an engine control unit are consistent with an in-house GM test rig). It is a method/process asset, not a sellable product — which is exactly why it has no commercial "product" footprint and also why that fact carries no NPE weight here.
• Current status: Operating. GM Global Technology Operations LLC remains an active, high-volume patent filer (≈11.7k–16.6k granted US patents tracked; rank ~#28 among US assignees). The patent itself, however, is expired for failure to pay maintenance fees under 37 CFR 1.362, effective 2025-02-21 (lapse notice 2025-03-31), notwithstanding an adjusted expiration of 2033-06-11.

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Assignment timeline

Three recorded events. Only one is a substantive transfer of title, and it is the original inventor→company assignment. There is no recorded post-issuance assignment of this patent.

1. 2010-12-28 / 2011-01-03 (executed) / recorded 2011-01-05 — Reel 025589/0385

• Conveyance: Assignment (ASSIGNMENT OF ASSIGNORS INTEREST)
• Assignor: OBLIZAJEK, KENNETH L.; SOPOCI, JOHN D.; ADAMS, WILLIAM KEITH (signing dates 2010-12-28 to 2011-01-03)
• Assignee: GM Global Technology Operations LLC, Michigan
• Correspondent: Not recoverable. The Google Patents legal-events mirror truncates the record before the correspondent block, and I could not reach Assignment Center directly. The prosecution agent of record shown on the published patent is LKGLOBAL (GM), Scottsdale, AZ (per FreePatentsOnline); that is the prosecution correspondent and is not evidence of the assignment-recordation correspondent. Flagging as unknown rather than assuming.
• Context: Ordinary employee invention assignment made pre-filing — no sale, no third party.

2. 2012-06-28 (recorded) — Reel 028466/0870

• Conveyance: Security Agreement (SECURITY AGREEMENT; ASSIGNOR: GM GLOBAL TECHNOLOGY OPERATIONS LLC)
• Assignor / Grantor: GM Global Technology Operations LLC
• Assignee / Secured Party: Wilmington Trust Company, Delaware
• Effective date of instrument: 2010-10-27
• Correspondent: Not recoverable (same limitation as above).
• Context: Securitization / collateral encumbrance, not a transfer of ownership. This is GM's post-bankruptcy-emergence collateral package — the same Wilmington Trust security grant and release pattern appears across swaths of GM's portfolio (e.g., reels 025327/0001–0041, 034184/0001, 034371/0676 on GM patents such as US 7,864,926 and US 7,264,071). Wilmington Trust is acting as collateral trustee, not as an acquirer.

3. 2014-11-07 (recorded) — Reel 034287/0159

• Conveyance: Release by Secured Party (RELEASE BY SECURED PARTY; ASSIGNOR: WILMINGTON TRUST COMPANY)
• Assignor / Releasing Party: Wilmington Trust Company
• Assignee / Beneficiary: GM Global Technology Operations LLC, Michigan
• Effective date: 2014-10-17
• Correspondent: Not recoverable.
• Context: Lien release returning the patent to a clean GM title. Confirms GM's ownership was never divested.

Events 2 and 3 cancel out. Net effect of the entire recorded chain: title went inventors → GM in 2011 and has sat with GM ever since. There is no assignment, license recordation, merger, or change-of-name event after grant, and no evidence in the record of any transfer to an IP-holding or licensing LLC.

Litigation cross-check: I searched for infringement actions naming US 9,574,972 and for the patent's number alongside the inventor names. No assertion was found. The only GM–steering IP litigation surfaced was GM's design-patent appeal against LKQ (Fed. Cir. 22-1253, skid-bar design, unrelated patent), which is GM asserting as a manufacturer against a competitor on a different asset — not this patent, and not an NPE chain.

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Timeline diagram

timeline
    title Ownership of US 9574972
    2010 : Inventors execute assignment to GM
    2011 : Filed 2011-01-05 by GM Global Tech Ops
         : Assignment recorded reel 025589/0385
    2012 : Security agreement to Wilmington Trust
         : Recorded reel 028466/0870
    2014 : Lien released back to GM
         : Recorded reel 034287/0159
    2017 : Patent granted 2017-02-21
    2020 : 4th year maintenance fee paid
    2025 : Patent lapsed for nonpayment

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NPE / troll-pattern signals

1. Shell-entity transfer — NOT PRESENT.
The only conveyance off the inventors is to GM Global Technology Operations LLC (reel 025589/0385). No "IP / Patents / Licensing / Holdings / Ventures" entity, no registered-agent service address, no single-purpose Delaware/Texas LLC appears anywhere in the chain. The one non-GM counterparty, Wilmington Trust Company (reel 028466/0870), is a corporate trustee taking collateral, and it released that interest at reel 034287/0159.

2. Known asserter in the chain — NOT PRESENT.
Neither GM Global Technology Operations LLC nor Wilmington Trust Company matches any public NPE roster (Acacia, Marathon, IV, IPNav, Wi-LAN, Mosaid/Conversant, Vringo, Pendrell, Innovatio, MPHJ, Lumen View, Round Rock, Document Generation Corp, Spangenberg entities). The only third-party assignees on the family are GM's own foreign counterparts (KR101314087B1, DE102011089950B4, CN102589906B) — the same corporate family, not a transfer.

3. Repeat correspondent across the chain — UNCLEAR (data not retrievable).
No correspondent-of-record field was obtainable for any of the three reel/frame entries, so I cannot test recurrence. The single correspondent datum I can confirm is the prosecution agent of record, LKGLOBAL (GM) of Scottsdale, AZ — a GM-dedicated Outside Counsel firm, not an NPE recording mill. I am explicitly declining to call this signal either way rather than manufacture a recurrence finding from prosecution counsel.

4. Cascading transfers — NOT PRESENT.
Two of the three events are the encumbrance and its release, spanning 2012→2014 with the asset never leaving GM. There is no sequence of chained LLCs, no shared correspondent address, no sub-24-month hop chain. Zero transfers post-grant.

5. Pre-litigation transfer — NOT PRESENT.
No infringement suit naming this patent was found, so the "assignment within 6 months before first suit" trigger cannot be satisfied. The asset is expired and has no assertion history.

6. Bankruptcy fire-sale — NOT PRESENT (with a nuance worth recording).
General Motors' Chapter 11 was a 2009 proceeding (Old GM → Motors Liquidation Co.; new GM assets sold under §363). This patent post-dates that entirely — it was filed 2011-01-05 against the successor entity. The Wilmington Trust security grant (effective 2010-10-27, recorded 2012-06-28) is part of GM's post-emergence financing collateral package, and it was released on 2014-10-17. Nothing here is a bankruptcy-court patent sale, and no sales process touched this asset.

7. Privateering — NOT PRESENT.
No transfer to an NPE with a GM enforcement mandate, and no SEC 10-K/8-K or Patent Progress/EFF coverage linking this patent to a proxy assertion campaign. GM has not spun this asset out.

8. Defensive aggregator (anti-NPE) — NOT PRESENT.
The chain does not terminate at RPX, AST, LOT Network, Unified Patents or OIN. The patent was neutralized by a different mechanism: failure to pay maintenance fees (patent expired for nonpayment effective 2025-02-21). That makes it non-assertable, but by lapse — not by defensive acquisition.

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Verdict

Insufficient data (no post-issuance assignment; chain consists of the original inventor→GM assignment plus a security interest and its release).

Justification: The complete recorded chain is three events — inventors→GM Global Technology Operations LLC at reel 025589/0385 (executed 2010-12-28/2011-01-03, recorded 2011-01-05), a collateral grant to Wilmington Trust Company at reel 028466/0870 (recorded 2012-06-28), and Wilmington Trust's release back to GM at reel 034287/0159 (recorded 2014-11-07). Those last two net to zero, leaving GM as the sole owner from 2011 through the patent's expiry for nonpayment in 2025. No NPE signal is present on any of the eight tests, and no assertion or assignment activity involving this patent was found; the 2010-12-28 signing dates relative to the 2011-01-05 filing date confirm this was ordinary employee-to-employer assignment, not a transfer arranged for enforcement.

Caveat on confidence: the absence of NPE signals is well-supported for the corporate chain, but the correspondent-of-record fields were not retrievable through the sources available to me, which is the one field that could reveal a recording agent hiding behind an innocuous chain. If you need that closed out, pull the three records directly in Assignment Center (search 9574972) and compare the correspondent blocks on reels 025589/0385, 028466/0870 and 034287/0159 — I expect them all to be GM's own IP operations or GM's outside counsel, but I have not verified it and am not asserting it.

I'll research the prior art references cited in US 9,574,972, prioritizing the ones most likely to be relevant to its claims. Let me run several targeted searches.

Let me gather details on the remaining key references.

Prior Art Analysis — U.S. Patent No. 9,574,972 ("Methods and systems for evaluating vehicle steering systems")

Verification of the target document (searching USPTO / Google Patents for the literal number "9574972"):

Because the filing date is 2011-01-05, the critical dates are: § 102(b) statutory bar = publications before 2010-01-05; § 102(a)/(e) = publications/applications before the invention date (≈ the filing date).

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Bottom line on anticipation

No single reference cited in US 9,574,972 anticipates any claim under 35 U.S.C. § 102. The 22 patent citations plus 4 non-patent citations that the examiner listed are almost entirely background or § 103 combinable art. The two limitations that do the patentable work — (i) calculating a "gear sensitivity / gear stiffness / gear impedance / motor ratio" (claims 1, 6–10, 15, 19) and (ii) determining a maximum angular-acceleration time and analyzing a time window around it (claim 11) — are not disclosed by any cited reference. The cited art does, however, disclose the underlying excitation/measurement scaffolding, chiefly:

• simultaneously loading the rack and vibrating the steering column on a bench (Toyota family: US 5,700,951 / DE 19622687 A1);
• dither excitation of a steering column with accelerometers on the steering-wheel rim to measure angular acceleration (GM's own US 2010/0031739 A1 / US 7,765,858 B2 — same two of the three named inventors);
• lab rack excitation with rack-acceleration measurement (GM's US 2009/0204343 A1).

These combine very naturally against claims 1–5, 11–13, 15–18 under § 103, but each missing element prevents § 102 anticipation.

Note on one citation that is not § 102 art at all: US 2012/0150389 A1 (GM, "Electric power steering systems with improved road feel") published 2012-06-14, after this patent's 2011-01-05 filing date; it can only be relied on, if at all, under § 102(e) via its 2010-12-14 priority — and its subject matter (EPS road-feel control) is remote from the testing claims.

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The 22 patent citations (as listed on the face of US 9,574,972)

Legend: "Claims potentially implicated" identifies the claims whose elements a reference touches; anticipation of a given claim requires all its elements in one reference. Dates are taken from the patent's own citation table (priority date / publication date) unless a search verified otherwise.

Tier 1 — Most relevant (bench-test methodology)

1. US 2010/0031739 A1 — "Method of measuring torsional dynamics of a steering column at small dynamic amplitudes"

• Full citation: U.S. Pub. No. 2010/0031739 A1; app. no. 12/188,540; inventors Kenneth L. Oblizajek & John D. Sopoci; assignee GM Global Technology Operations, Inc. Granted as US 7,765,858 B2 (2010-08-03).
• Dates: priority 2008-08-08; published 2010-02-11.
• Description (verified): Mounts a steering column assembly in a test fixture; applies periodic/sinusoidal input excitations (≈1–30 Hz), torque-motor or shaker driven, plus dither excitation; attaches accelerometers to the steering-wheel rim to measure angular acceleration; can substitute an equivalent bar with matched polar moment of inertia (PMI); computes natural frequency and "steering-wheel rim gain," compared to predetermined limits.
• § 102 analysis / claims: The closest reference; overlapping inventors (Oblizajek, Sopoci) and common assignee make it a § 102(a)/(e)-type candidate. It discloses the claim-1/claim-2 "dither the steering-wheel mass" and "measuring an acceleration of steering" concepts, and the claim-5/claim-13 steering-state sensing. It does not disclose manipulating the rack (no rack excitation) and does not calculate gear sensitivity / gear stiffness / gear impedance / motor ratio (it computes rim gain and natural frequency). → No anticipation of claims 1, 11, 15. Strong § 103 art for the column-side elements.

2. US 5,700,951 A — "Testing apparatus of steering system"

• Full citation: U.S. Patent No. 5,700,951; inventors Matsushima Takashi et al.; assignee Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corp.).
• Dates: priority 1995-06-07; filed 1996-05-28; granted 1997-12-23.
• Description (verified): Bench test apparatus that applies load to the rack/tie-rod (via a steering-angle vibrating unit and a vertically-vibrating unit, connected through a link system) and simultaneously drives the pinion shaft/steering (steering-angle vibrating unit); load detected by transducers.
• § 102 analysis / claims: § 102(b) art (granted >1 yr before filing). Discloses the claim-1(a) "manipulating the rack" and claim-1(b) "manipulating the steering column" steps on a test bench, and load measurement (claim 3 analogue). Does not measure acceleration of steering and does not compute the claimed ratios. → No anticipation of claim 1, but it is the strongest § 102(b) art for the dual-manipulation concept.

3. DE 19622687 A1 / C2 — "Test bed for vehicle steering system" (Prüfstand für ein Lenkungssystem)

• Full citation: DE 196 22 687 A1 (and granted DE 19622687 C2); same Toyota inventors (Iizuka, Saito, Matsushima, Baba, Sagiyama); assignee Toyota Motor Corp.
• Dates: priority 1995-06-07/08; published 1996-12-12.
• Description (verified): Test bed with two loading devices — one acting in the steering-force direction, one in the opposing road-surface-force direction — using parallel-link mechanisms, with load detectors on the links. This is the German sibling of US 5,700,951.
• § 102 analysis / claims: § 102(b) art. Same analysis as US 5,700,951 (rack + steering loading). → No anticipation; combined with US 2010/0031739 it is a § 103 attack on claims 1–5.

4. US 2009/0204343 A1 — "Test procedure for determining steering rack rattle"

• Full citation: U.S. Pub. No. 2009/0204343 A1; app. no. 12/193,930 family (granted as US 7,742,899 B2); assignee GM Global Technology Operations, Inc. (inventor incl. Marc J. Tahnoose).
• Dates: priority 2008-02-12; published 2009-08-13.
• Description (verified): Lab method mounting a steering assembly to a shaker, applying predetermined force profiles to the steering assembly, and measuring rack acceleration with an accelerometer (plus tie-rod loads and audio); band-pass/low-pass filtering and RMS metrics.
• § 102 analysis / claims: Published <1 yr before filing → § 102(a)/(e), not § 102(b). Touches claim 1's rack manipulation and claim 4's "measuring an acceleration of the rack." Does not disclose column manipulation, steering acceleration, or the claimed ratios/time-window. → No anticipation.

5. DE 10 2006 016764 A1 — "Motor vehicle steering system controlling method…"

• Full citation: DE 10 2006 016764 A1 (granted DE 102006016764 B4, 2009-04-30); assignee GM Global Technology Operations, Inc., Detroit.
• Dates: priority 2006-04-10; published 2007-10-18.
• Description (from the patent's citation entry): "…fixing steering system to steering test stand, and transmitting mechanical force to center of steering system by actuator such as piston cylinder unit."
• § 102 analysis / claims: § 102(b) art (published >1 yr before filing). Discloses mounting the steering system to a test stand and applying mechanical force via an actuator → claim 1(a) "manipulating the rack." → No anticipation; useful § 103 component for the mounting/racking step.

Tier 2 — Secondary bench-test / instrumentation art

6. US 2005/0022587 A1 — "Vehicle test stand"

• Schenck Final Assembly Products GmbH; priority 2003-06-25; published 2005-02-03; § 102(b). Generic vehicle test stand. → Background/§ 103 only.

7. US 4,672,844 A — "Testing apparatus with improved follower mechanism"

• Schenck Pegasus; priority 1986-03-26; granted 1987-06-16; § 102(b). Servo/follower test-rig mechanics. → Background only.

8. US 5,880,381 A — "Method of testing vehicle parts"

• TRW Inc.; priority 1996-12-12; granted 1999-03-09; § 102(b). Component test method. → Background; possibly § 103 for "collecting data… for evaluating the steering system."

9. US 5,345,764 A — "Control valve for bootstrap hydraulic systems"

• Techco Corporation; priority 1991-05-10; granted 1994-09-13; § 102(b). Hydraulic power-steering component. → Background only (relates to HPS, not test methodology).

10. KR 10-2006-0133704 A — "Angular speed sensor for vehicle steering"

• 대성전기공업 주식회사 (Daesung Electric); priority 2005-06-21; published 2006-12-27; § 102(b). Steering angular-speed sensing. → Possibly § 103 for motor-speed/steering-angle sensing (claim 5/claim 13 analogue); not anticipatory.

11. KR 2000-0056905 A — "Hardware-In-the-Loop-Simulation (HILS) System for Testing Electric Power Steering Systems"

• Inventor/applicant 김효근 (Kim Hyo-geun); priority 1999-02-27; published 2000-09-15; § 102(b). HILS test rig for EPS. → Background/§ 103 for the EPS-motor investigation (claim 10/19 analogue); not anticipatory.

12. US 2005/0284245 A1 — "Integrated design system of electric power steering system"

• Inventor Hui Chen (family incl. JP 4019918 B2); priority 2002-11-28; published 2005-12-29; § 102(b). EPS design/analysis system. → § 103 for computing steering-system quantities; not anticipatory.

13. US 2010/0017064 A1 — "Method for tuning electric power steering apparatus"

• NSK Ltd.; priority 2006-10-30; published 2010-01-21 (just after the 2010-01-05 § 102(b) cutoff → § 102(a)/(e)). EPS tuning. → § 103 for "motor ratio"-type EPS analysis; not anticipatory.

14. US 2007/0175695 A1 — "Steering gear"

• Dishop Steering Technology Limited; priority 2003-09-22; published 2007-08-02; § 102(b). Steering-gear hardware. → Background only.

15. CN 101 017 117 A — "Durability testing stand of electric power-assisted steering system"

• 清华大学 (Tsinghua University); priority 2007-02-28; published 2007-08-15; § 102(b). Durability test stand. → Background/§ 103; not anticipatory (durability, not dynamic-ratio evaluation).

16. CN 101 696 908 A — "Device for testing performance of automotive steering system"

• 重庆理工大学 (Chongqing University of Technology); priority 2009-10-19; published 2010-04-21 (→ § 102(a), not § 102(b)). Steering-system performance test device. → § 103; not anticipatory.

Tier 3 — Steering-wheel hardware and off-point art

17. US 2011/0153160 A1 — "Steering wheel assembly for a motor vehicle" (and its CN 101 821 149 A counterpart)

• Takata-Petri AG; priority 2007-09-06; US published 2011-06-23 (after the filing date → § 102(e) only via its earlier filing); CN published 2010-09-01 (§ 102(a)). Steering-wheel assembly hardware. → Not prior art to the testing claims; cited for the steering-wheel-mass/accelerometer background.

18. US 2012/0150389 A1 — "Electric power steering systems with improved road feel"

• GM Global Technology Operations LLC; priority 2010-12-14; published 2012-06-14 (after filing → § 102(e) at most). EPS control, not testing. → Not anticipatory.

19. US 4,372,844 A — "Aromatic and benzothiophene extender oil composition for ore floatation"

• Phillips Petroleum Company; priority 1981-06-29; granted 1983-02-08; § 102(b).
• ⚠ Flag: On its face this is a petroleum/ore-floatation composition patent with no apparent technical relationship to steering-system testing. It may be a citation-table artifact, or relate to a lubricant/grease property tested alongside the gear. It cannot anticipate any claim. I flag it because it is anomalous relative to the rest of the list.

20. CN 101 509 807 A — "Test procedure for determining steering rack rattle"

• 通用汽车环球科技运作公司 (GM Global Technology Operations, CN); priority 2008-02-12; published 2009-08-19; § 102(a). Chinese counterpart of US 2009/0204343 A1 (item 4). Same analysis → not anticipatory.

21. (duplicate family) Items 17 and its CN counterpart are the same disclosure; likewise item 4 and item 20. The count of 22 entries therefore includes at least two duplicative families — worth noting if you are scoring citation breadth.

(The remaining entries in the "Cited By"/"Similar Documents" tables are forward citations and unrelated documents, not prior art, and are excluded.)

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Non-patent citations (4) — all are prosecution documents or a printed publication

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Claim-by-claim anticipation scorecard

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Methodological caveats (please read before relying on this)

1. Anticipation vs. obviousness. I have mapped each reference to the claim elements it touches. Under § 102, a claim is anticipated only if a single reference discloses every element. On this record none does; the realistic challenge is § 103 (e.g., US 5,700,951 or DE 19622687 for the dual-manipulation bench + US 2010/0031739 for column dither/steering-wheel acceleration + a general optimizing/measurement reference for the ratio math).
2. The strongest reference is the assignee's own earlier application. US 2010/0031739 A1 / US 7,765,858 B2 shares inventors Oblizajek and Sopoci with the patent under analysis. That raises § 102(e)/common-ownership and possibly derivation-type questions that a full validity opinion must address — I flag it but do not resolve it here.
3. Verification limits. I directly verified the content of US 5,700,951, DE 19622687, US 2009/0204343, US 2010/0031739, and the target patent. For the balance of the citations I relied on the patent's own citation table (titles/dates/assignees) and did not pull full texts; treat the "brief description" fields for those as title-level characterizations. I could not retrieve the Qatu et al. (2001) paper or the full texts of US 6,055,853, US 5,880,381, US 2005/0022587, DE 10 2006 016764, or KR 2000-0056905 in this session; those are flagged accordingly.
4. No auto-correction. All identifiers were matched literally. For example, the "Kokusai Keisokuki" and "Thyssenkrupp Presta" documents in the forward-citation tables are not prior art to this patent and were not treated as such; and US 4,372,844 (item 19) is reported as cited even though its subject matter is anomalous.
5. No contradiction was found with the previously generated Litigation section; the fee-lapse dates (last 4th-year fee 2020-08-06; lapse effective 2025-02-21) agree with the "Expired – Fee Related" status in the authoritative full text.

If you want, I can next produce a formal element-by-element § 103 combination chart (primary reference + secondary references + motivation to combine) for claims 1, 11, and 15, which are the independent claims most exposed to an obviousness challenge.

I'll ground this analysis in the prior art actually cited on the patent's face. Let me pull details on the key references.

Let me pull the remaining key references — TRW, Navistar, Schenck Pegasus, Toyota's DE '687, and the Qatu NPL.

Obviousness Analysis — U.S. Patent No. 9,574,972 under 35 U.S.C. § 103

Date note (carried forward): The prior sections in this file flagged a discrepancy between the stated current date (April 26, 2026) and the system context (September 29, 2026). The same discrepancy persists here. It does not affect the analysis: 9,574,972 is a pre-AIA patent (filed 2011-01-05), and its status (expired for fee non-payment, effective 2025-02-21) is unchanged under either date. I flag it rather than resolve it, as instructed.

Scope: Per instruction, this analysis is grounded in the prior art cited on the face of 9,574,972 — the "Patent Citations (22)," the "Cited By," and the "Non-Patent Citations (4)" identified on the Google Patents record at https://patents.google.com/patent/[US9574972B2](/patent/US9574972B2)/en. I build on, and do not repeat, the claim summaries and bibliographic tables in the previously generated sections.

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1. Threshold issue that governs the whole analysis: which cited references are usable art

Because 9,574,972 is pre-AIA, § 102/§ 103 as they existed before March 16, 2013 control. Two consequences matter and are frequently missed:

(a) § 102(b) vs. § 102(e) status of each reference. A reference is § 102(b) art only if published/patented more than one year before the 2011-01-05 filing date (i.e., before 2010-01-05).

(b) § 103(c) common-ownership disqualification. Subject matter that qualifies as prior art only under § 102(e), (f) or (g), and that was owned by the same person as the claimed invention at the time the invention was made, cannot be used in a § 103 combination. Several of the cited references are GM-owned. § 103(c) does not reach § 102(b) art, so a GM reference published before 2010-01-05 remains fully usable despite common ownership.

Key takeaway: A defensible § 103 challenge should be built on the § 102(b) references, which survive common-ownership attack. The most convenient GM references — US 2009/0204343 ('343) and DE 10 2006 016 764 ('764) — are § 102(b) and therefore safe. The GM column-dynamics reference US 2010/0031739 ('739) is § 102(e)-only and risks § 103(c) disqualification; the analysis below therefore identifies non-GM substitutes for its teachings so the combination does not depend on it.

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2. One-sentence statement of the invention, for § 103 purposes

The claims are directed to bench-testing a complete rack-and-pinion steering gear by simultaneously exciting it at both of its two mechanical input ports — the rack (road-side) and the column/wheel (driver-side) — and converting the measured force/acceleration data into standard frequency-domain transfer quantities (mechanical immittances) that characterize the gear, plus (claim 11) a sub-step of windowing the data around the peak steering-wheel angular acceleration.

The two-part core is therefore: (i) dual-port excitation of a steering gear on a test stand, and (ii) computing conventional vibration-transfer-function metrics from the data.

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3. The primary combination

Ground 1: TRW '381 + GM '343 + GM '764 (with '951 as an alternative for the actuator teaching)

Ground 2 (alternative/fallback): Toyota '951 + GM '343 + GM '739

US 5,700,951 (Toyota) is arguably the single most structurally on-point reference for the dual-port test-stand concept: it discloses both a device that applies steering-reaction-force-direction load (via the column/pinion) and a device that applies road-surface-force-direction load (via the rack), simultaneously, with load detectors. Adding '343 supplies the rack-acceleration measurement + FFT/RMS conditioning, and '739 (GM; § 102(e)) supplies:

• mounting the column assembly on a test fixture (test fixture 10);
• applying input excitations — "sinusoidal excitations," "swept-sine or sine-dwell," and expressly dither — to the input end, i.e., manipulating the steering column;
• accelerometers 32 attached to the rim (outer portion) of steering wheel 30 to measure the angular acceleration of steering wheel 30 — i.e., "measuring an acceleration of steering" at the steering-wheel mass;
• an equivalent bar whose polar moment of inertia (PMI) approximates the steering wheel's — i.e., exactly the "steering wheel mass … a representative mass with a predetermined or measurable PMI" of the '972 specification;
• a control system 34 that logs output conditions as a function of frequency and fits data to a single-degree-of-freedom model containing spring constant, damping constant and PMI, then compares a derived rim gain to a predetermined permissible range.

See https://patents.google.com/patent/US20100031739A1.

Because '739's "rim gain" and single-DOF parameter fit are transfer-function/compliance metrics, they bridge directly to the claimed "gear sensitivity / stiffness / impedance" family. If '739 is disqualified by § 103(c), the same teachings are recoverable from the non-GM § 102(b) art ('951's vibrating units + '853's steering-wheel monitor + DE 19622687 (Toyota "test bed for vehicle steering system") or CN 101017117 (Tsinghua EPS durability stand)), so the combination is not hostage to the common-ownership issue.

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4. Claim-by-claim mapping (representative)

Claim 1 — Method; closed Markush group of four values.

• Manipulate rack + manipulate column + collect data incl. steering acceleration: '381 (both manipulations) + '343 (rack acceleration measurement) + '951 (column drive) + '853/'739 (steering-wheel acceleration).
• "Value selected from {gear sensitivity, gear stiffness, gear impedance, motor ratio}": see § 5. Note only one of the four need be shown obvious — the claim is met by any single member of the group.

Claim 2 (dither the steering wheel mass) — Expressly disclosed in '739: "dither may also be applied…"; and '739's excitation devices impart torque to the steering shaft. Near-verbatim.

Claim 3 (measure rack force) — '343 (force profile applied to rack; tie-rod force sensors); '951 (load detectors); '381 (test-stand actuation with load feedback).

Claim 4 (measure rack acceleration) — '343's accelerometer 40 measures rack acceleration directly.

Claim 5 (measure steering angle) — '951's "steering-angle vibrating unit" and '739/'343's logging of input displacement.

Claims 6–8, 10, 19 (compute gear sensitivity / stiffness / impedance / motor ratio) — § 5.

Claim 9 (compute gear ratio) — not in claim 1's Markush group; a steer ratio between wheel angular motion and rack linear motion is a textbook steering-gear parameter and follows directly from the '739 transfer-gain approach.

Claim 11 (determine max angular-acceleration time; use a window around it) — '343 teaches time-domain characterization of acceleration events, including event "rise time, event duration, frequency content, and time structure," selecting peaks of RMS values, and defined integration-time windows (20–400 ms) within which levels are computed. Window-around-peak is a routine time-domain segmentation once the quantities to be averaged are known. See § 6.

Claim 15 (system) — same combination in apparatus form:

• First actuator → manipulate the rack: '951's "vertically-vibrating unit"/second loading device; '764's actuator (German abstract notes "actuator such as piston cylinder unit"); '343's force input table.
• Second actuator → manipulate the column: '951's "steering-angle vibrating unit"; '739's electromagnetic shakers / torque motor.
• Sensor unit (data incl. measured steering acceleration): '739's rim accelerometers 32; '343's accelerometer 40; '853's steering-wheel monitor.
• Processor calculating one or more of gear stiffness/impedance/sensitivity/motor ratio: '739's control system 34; '343's "data acquisition and analysis processor 42."

Dependents 12–18 map onto the same references (12→'343/'951 force + rack-accel sensors; 13→'739/'853 wheel-accel + steering-angle sensors; 16→'343 accelerometer + force sensors; 17→'739 dither; 18→'853).

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5. Why the "calculate a value" limitation — the crux of the case — would have been obvious

This is the only limitation that no single reference states in haec verba, and it is where a challenger must do real work. The argument is that the four recited values are textbook mechanical-impedance / frequency-response-function (FRF) quantities, and that the '972 formulas confirm this:

• Gear stiffness = Fr/(Ar − Ah) · (−(2πf)²)/1000. Dividing a force spectrum by an acceleration spectrum and multiplying by −ω² converts acceleration to displacement — i.e., it computes force ÷ relative (rack-to-housing) displacement. That is the definition of a dynamic stiffness.
• Gear impedance = Fr/Ar · (−(2πf)²)/1000 — the same conversion applied to rack acceleration → force ÷ rack displacement: mechanical impedance referenced to ground, a standard textbook quantity.
• Gear sensitivity = AAsw/Fr — angular acceleration ÷ force, i.e., a transfer accelerance (an FRF).
• Motor ratio = Vm/(Ar − Ah) · (−2πf)/(1000·i) — motor speed ÷ relative displacement, a kinematic/velocity transfer ratio.

Once the '343 and '951 combinations put a force sensor, accelerometers, and (for EPS) a motor-speed pick-up on a bench-mounted gear, and once '343's own disclosure shows FFT/RMS processing in a chosen frequency band, taking ratios of the resulting complex spectra is not an inventive act — it is the ordinary practice of experimental modal analysis and system identification. KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398 (2007), governs: where a known technique (FRF processing) is applied to a known data set in a predictable way to yield a predictable quantity (a stiffness/impedance/gain value), the result is obvious. The Qatu, Llewellyn & Spadafora, Experimental Mechanics (2001) 41:151 NPL citation on the face of the patent — an experimental-mechanics paper on the steering system — is consistent with FRF-type measurement being the accepted methodology in this field, i.e., within the ordinary skill level. (Note: I was unable to retrieve the full text of this NPL within my search budget — see § 8.)

A parallel argument is '739's own derived quantities: natural frequency, spring constant, damping constant, and "rim gain," compared to permissible ranges. Deriving a second, algebraically equivalent transfer quantity from the same measurement set is an obvious design choice of which FRF to report.

**Because each of claims 1 and 15 requires only one member of the enumerated group, the obviousness case reduces to showing that at least one metric — the dynamic stiffness (gear stiffness) or mechanical impedance is the cleanest target — would have been obvious. On the analysis above, that showing is strong.

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6. Claim 11's window-around-max-angular-acceleration

Claim 11 adds: (a) determine a maximum angular acceleration time for the data, and (b) calculate the value using a window around that time.

No single cited reference states this step verbatim, but the combination makes it an obvious refinement:

• '343 already operates in the time domain to isolate transient acceleration events, characterizing event "rise time, event duration, frequency content, and time structure," computing peaks of RMS values, and averaging over defined integration windows (20–400 ms). Selecting the window about the largest peak is the limiting case of that known practice.
• '739 sweeps the input frequency and logs output conditions versus frequency, and the '972 specification itself explains the window's purpose (isolating the instant "static friction … has been substantially broken"). Isolating the regime in which a nonlinear (stick-slip) element has broken free, by windowing on the response peak, is a routine signal-processing expedient that a POSITA would apply to remove friction-induced distortion from an FRF estimate.
• The art of US 9,604,665 / 9,669,867 / 9,950,736 (GM's later stiction/stick-slip characterization cases, cited in the "Family Citing" list) corroborates that the stick-slip/friction-break problem was known and separately addressed in the field — supporting the motivation.

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7. Motivation to combine (KSR factors)

1. Same field, same problem, overlapping disclosure. All of '343, '764, '951, '381, '739, '853 and '844 are directed to bench/testing measurement of vehicle steering systems (CPC G01M 17/06; B62D 5). The '972 itself is classified in G01M17/06, B62D5/04, G01L5/221, B60W50/04 — the same neighborhoods.
2. The rack and the column are the two necessary input ports of a rack-and-pinion gear. A POSITA seeking to characterize a complete steering gear would necessarily excite both; '381 states this almost verbatim ("rotate the input shaft … and simultaneously … move the rack"), and '951 implements it with two loading devices. Combining a known rack-excitation method with a known column-excitation method is combining known elements "according to known methods … to yield predictable results." KSR, 550 U.S. at 416.
3. Reasonable expectation of success / predictable results. Each reference independently produces usable bench data; aggregating the two excitation paths merely yields a richer data set. Nothing in the art teaches away.
4. Design incentive. '343 and '739 each articulate the same background motivation stated in the '972 — that testing at the component/bench level isolates steering-system behavior from extraneous vehicle noise and enables engineering-out of defects before vehicle build ("allowing rattles to be engineered out of steering systems prior to building full vehicles"). See '343, [0006]–[0007]. This is a shared, express motivation to extend bench testing from a single component to the whole gear.
5. Known technique applied to known data. FRF/immittance computation (Qatu; standard practice) applied to the aggregated sensor set — predictable result (KSR § 3).

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8. Defenses the patentee could raise — and the honest weaknesses in this analysis

1. § 103(c) common-ownership disqualification (the strongest defense). As set out in § 1, US 2010/0031739 A1 (and US 2012/0150389 A1) are GM-owned and qualify only under § 102(e). If GM can show common ownership/obligation of assignment at the time of invention, those references are unusable in a § 103 combination against the GM-owned '972. A challenger must therefore anchor on § 102(b) art. I have supplied the non-GM § 102(b) alternatives ('951, '853, '381, DE 19622687, CN 101017117) that carry the same teachings, so the combination survives — but the cleanest mapping (rim accelerometers + dither + PMI-equivalent mass) comes from '739, so this is a genuine vulnerability worth stating plainly.
2. No verbatim teaching of the four named metrics. None of the cited references names "gear sensitivity," "gear stiffness," "gear impedance," or "motor ratio." The obviousness case rests on the characterization that these are conventional immittances (which the '972 formulas themselves support). A patentee would argue the specific selection and pairing of these ratios, and the −ω² / −2πf / (1000·i) unit conversions, are not suggested — i.e., that the inventors made a non-obvious choice of which transfer functions to define. This is the most contestable point.
3. The examiner allowed the claims (19 claims; primary examiner noted as Peter D. Nolan in the prior section, from FreePatentsOnline). The PTO evidently did not treat '343/'739/'951 as rendering these claims obvious — although '343 and '739 are cited as prior art of record, which actually strengthens the "these references were in front of the examiner" backdrop: they were cited but were evidently not combined in a rejection, presumably because no single reference taught both manipulations. That is precisely the gap this § 103 analysis is designed to fill.
4. Secondary considerations — effectively unavailable. There is no known litigation, no licensing, no commercial-success evidence tied to these claims, and the patent lapsed for fee non-payment in 2025. The only possibly probative item would be industry praise for the methodology (as '343's and '739's specifications describe lab-test advantages generally), but that praise attaches to the prior art too and would lack nexus to the '972 claims specifically.
5. Claim 1's closed Markush group excludes gear ratio (gear ratio appears only in dependent claim 9). This narrows the claim-1 case to the four metrics but, per § 5, does not defeat it.

Retrieval limitations (explicit): My search budget expired before I could retrieve the full texts of US 6,055,853 (Navistar), US 4,672,844 (Schenck Pegasus), DE 19622687 A1 (Toyota) and the Qatu et al. NPL. I have relied on their titles/abstracts and on the characterizations in the '972 specification's own citation table. I have not verified the internal content of those four beyond what appears in the record. I also have only the German claim text for DE 10 2006 016 764 A1 and its English abstract. Any of these points should be re-verified against the full documents before being relied upon.

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9. Conclusion

On the cited art, claims 1–19 of U.S. 9,574,972 are vulnerable to a § 103 challenge, most plausibly on:
Ground 1 — US 5,880,381 (TRW) + US 2009/0204343 A1 (GM) + DE 10 2006 016 764 A1 (GM), optionally supplemented by US 5,700,951 (Toyota) for the dual-loading-device test-stand teaching and by US 6,055,853 (Navistar) for steering-wheel monitoring; and
Ground 2 — US 5,700,951 + US 2009/0204343 + US 2010/0031739 A1 (GM) as a fallback, subject to the § 103(c) caveat on '739.

The strongest link in each ground is that '381/'951 teach simultaneous rack-and-column manipulation of a bench-mounted steering gear, '343 teaches the force/acceleration measurement and FFT/windowed processing of that data, and the recited "values" are conventional mechanical immittances computable from the measured spectra — a predictable application of a known technique. The weakest link — and the point on which this analysis would most likely be contested — is that no cited reference names or expressly derives the four enumerated metrics, so the obviousness conclusion there rests on the characterization of those metrics as standard FRF/immittance quantities rather than on an express teaching.

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Sources relied upon for this section (building on those already cited in the file):

• https://patents.google.com/patent/US9574972B2/en (claims, citations, family)
• https://patents.justia.com/patent/7742899 and https://patents.google.com/patent/US20090204343A1 (US 2009/0204343)
• https://patents.google.com/patent/US20100031739A1 and https://www.freepatentsonline.com/y2010/0031739.html (US 2010/0031739)
• https://patents.google.com/patent/DE102006016764A1 (DE 10 2006 016 764)
• https://patents.google.com/patent/US5700951A and https://insight.rpxcorp.com/patent/US5700951A (US 5,700,951)
• https://patentimages.storage.googleapis.com/be/f4/25/96d9c894a7e448/US5880381.pdf (US 5,880,381)