US 8167538

I'll search for authoritative information on this patent number, including any litigation activity.

Let me verify the litigation/docket question more specifically.

US Patent 8,167,538 — Verification & Summary

Identifier check: I searched for the exact number 8167538 (and 8,167,538). All authoritative hits returned the same document. One irrelevant hit — a Brazilian JUCISRS filing roster listing a person registration "8167538" — is not a patent and is excluded.

Bibliographic data

Abstract (as issued)

"A torque monitoring apparatus is disclosed herein. The torque monitoring apparatus includes a hub extending along an axis of rotation between first and second opposite ends. The torque monitoring apparatus also includes a plurality of spokes positioned on the hub and extending radially outward from the hub to respective distal ends. The torque monitoring apparatus also includes a plurality of projections spaced from the plurality of spokes along the axis of rotation. Each of the plurality of projections extends radially outward from the hub to respective distal ends. The plurality of projections are thinner along the axis than the plurality of spokes."

Plain-language overview of the independent claims

Claim 1 — the apparatus. A torque-monitoring coupler built around a hub that runs along a rotation axis, with two distinct sets of radial features: (a) a set of spokes projecting radially outward to free ends, and (b) a set of projections spaced axially away from the spokes, also projecting radially outward to free ends. The single structural limitation that defines the claim is dimensional: the projections must be thinner along the rotation axis than the spokes. The thicker spoke set carries the torque; the thinner projection set exists to be sensed.

Claim 10 — the method. Connect an input shaft and an output shaft through a torque monitoring apparatus that has a hub and two sets of radial projections. Then transmit torque through only the first set of radial projections — i.e., the second set is deliberately kept out of the torque path and serves only as a sensing/monitoring feature. This recites the functional corollary of the claim 1 geometry (only the thicker set transmits load).

Claim 14 — the turbine engine. A turbine engine with an input shaft and an output shaft rotatable about an axis, plus a torque monitoring apparatus including a hub, spokes whose distal ends are fixed to the input shaft, and axially-spaced projections that are thinner along the axis than the spokes. The distinguishing feature versus claim 1 is the positive recitation that the spoke ends are fixed to the input shaft (the disclosure describes this via a welded hoop).

Key dependent-claim concepts worth noting (for context, not exhaustive): a hoop interconnecting the spoke distal ends (claim 2); projection ends left circumferentially unconnected to ease sensing (claim 3); notches in the hoop (claim 4); different circumferential width/profile between projections and spokes, with projections optionally wider for detectability (claims 5–6); projections positioned closer to the spokes than to either hub end (claim 7); spokes tangent rather than normal to the hub for greater flex (claim 9, claim 17); projections normal to the hub (claim 18); dual sensors plus a controller determining torque from relative positions (claim 16); direct fixation of the output shaft to the hub (claim 15); and integral formation of hub/spokes/projections (claim 20).

Family / related-art notes

• The record lists a single family member (family ID 42108814) — no foreign siblings; country status shows US only.
• One family member citing this patent is US 7,810,402 B2 (Rolls-Royce Corporation, priority 2008-10-29, "Torque monitoring apparatus") — a closely related Rolls-Royce filing. The other is FR 3017657 B1 (Snecma, priority 2014-02-19, "Torsion disk torque measuring device for turbomachine").
• 13 examiner/third-party citations are listed, including US 4,809,557 (Ringspann), US 5,067,354 (Kyowa), US 5,450,761 and US 5,969,269 (Kop-Flex), US 7,322,250 and US 6,981,423 (Rockwell Automation), and US 7,665,373 (Kop-Flex, "Torque measuring device with redundant torque transmission paths and fail-safe mechanism").

CAFC 2026 docket / litigation search — no results found

I searched for CAFC 2026 activity and district-court litigation tied to this exact number. I found no CAFC appeal, no district-court docket, and no interference or PTAB proceeding involving US 8,167,538. Stated as an explicit uncertainty: I could not query the USPTO PatentCenter or the CAFC docket systems directly, and my searches returned no litigation records for this patent. Therefore I can report only that no litigation was surfaced by search, not that none exists. The Rolls-Royce v. United Technologies interference matter (603 F.3d 1325, Fed. Cir. 2010) that appears in results involves different patent numbers (the "'077 patent" and "'931 application") and is not related to 8,167,538.

If you need a definitive litigation clearance, the appropriate next step is a direct PatentCenter / PACER / CAFC CM/ECF docket pull, which is outside what these searches resolved.

I'll search for litigation involving US patent 8167538 across the sources you named.

Initial results were not responsive. Let me query the litigation-specific sources directly.

Let me try a few more targeted litigation-database queries.

Findings: Litigation involving U.S. Patent No. 8,167,538

No litigation was found involving U.S. Patent No. 8,167,538 ("Torque monitoring apparatus").

I searched for the specific number across patent-litigation aggregators and general web sources (including the Unified Patents litigation portal, RPX Insight, Docket Alarm, and CourtListener/PACER-derived materials). Every hit for the string "8167538" was a false positive — none of them related to this patent. Examples of the non-responsive hits returned:

• A Brazilian state-court document listing registry entries "8167537 / 8167538 / 8167539" (these are Brazilian registration/inscription numbers for individuals in a labor/extinction case in Rio Grande do Sul — not US patent numbers).
• Cases involving different patents whose docket numbers or patent numbers coincidentally contain similar digits (e.g., the '816 design patent in Nexus Techs., C.A. No. 1:19-cv-00009-MR (W.D.N.C.)).
• Numerous Unified Patents PTAB filings and IPRs concerning unrelated patents ('228, '508, '723, '002, etc.).

Case table

What I can confirm about the patent's prosecution/administrative history (not litigation)

• Patent: US 8,167,538 B2; Application No. 12/252,407; filed 2008-10-16; granted 2012-05-01; priority 2008-10-16.
• Inventors: Chris Norris; Matt Wilkinson. Assignee: Rolls-Royce Corporation (assignment recorded, reel/frame 021689/0050, effective 2008-10-03, executed as "ASSIGNMENT OF ASSIGNORS INTEREST").
• Pre-grant publication: US 2010/0098528 A1 (2010-04-22).
• Legal status listed: Active, with an adjusted expiration of 2031-01-08; maintenance fees paid (4th year 2015-11-02; 8th year 2019-11-01; 12th year 2023-10-24).
• The only "family citing" document shown is US 7,810,402 B2 (Rolls-Royce Corporation, "Torque monitoring apparatus," priority 2008-10-29) — this is a sibling/related Rolls-Royce patent, not a litigation party.

Caveats

• I did not find — and cannot rule out — a sealed, settled, or very recent case, or litigation in non-US forums, since the aggregator results I could retrieve were incomplete and returned mostly false positives for this number. The search tooling returned a step limit before I could fully exhaust Docket Alarm and direct PACER queries.
• This patent is a mechanical/turbomachinery torque-measurement device owned by a single operating company (Rolls-Royce). That profile is consistent with there being no enforcement litigation, but that is an inference, not a verified fact.
• If you need a definitive negative, I'd recommend a direct PACER/RECAP docket search and a Lex Machina/RPX Docket Navigator query on the exact string 8167538 and its application number 12/252,407, which I was unable to complete here.

PTAB Proceedings on U.S. Patent No. 8,167,538

Proceedings overview

Total AIA trial proceedings on file: 0 — zero active, zero with claims invalidated, zero with claims sustained, zero settled, and zero with institution denied; the structured "PTAB proceedings on file" block drawn from the USPTO Open Data Portal (ODP) returns an empty set for US 8,167,538, and independent web searches through 2026-09-30 surfaced no IPR, PGR, or CBM document naming this patent or its application number 12/252,407. Bottom line for a defendant: there is no PTAB record to lean on in either direction. No claims have been canceled, no claim has been tested, no petitioner has triggered § 315(e)(2) estoppel, and the patent stands exactly as it issued on 2012-05-01 with all 20 claims (independents 1, 10, 14) live — so an invalidity defense must be built from scratch, not inherited from a prior challenger.

No proceedings to tabulate

Because the structured list is empty, the per-proceeding sections (type, filing date, status, judge panel, grounds, institution decision, FWD, settlement, appeal, defensive value) have no content to report. No proceeding number is quoted here because none exists — inventing one would be the only way to fill those headings, and I will not do that.

What I affirmatively checked and what I found:

False positives excluded (the same ones the earlier sections flagged): the Brazilian JUCISRS registry listing "8167538 GIOVANNI SILVA DE MORAES" (a person registration number in a Rio Grande do Sul labor filing, not a US patent), and unrelated PTAB documents that merely contain similar digit strings in other case numbers. The Rolls-Royce v. United Technologies interference matter (603 F.3d 1325, Fed. Cir. 2010) concerns different patent numbers and does not involve 8,167,538.

Confidence statement: I can state with high confidence that no AIA trial proceeding appears in the ODP record or in the public web sources I could reach. I cannot rule out a very recently filed petition that ODP has not yet ingested, or a proceeding in which the patent is a secondary reference rather than the challenged patent. A definitive negative requires a direct PTAB E2E / Patent Center pull — the ODP ingest lag is the specific gap here.

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Strategic summary

Claim status. There is no IPR-narrowed claim set to work from. Of the 20 issued claims, 0 are CANCELED and 0 are SUSTAINED through PTAB; all 20 — including independent claim 1 (hub + spokes + axially-spaced, axially-thinner projections), independent claim 10 (method of transmitting torque through only the first set of radial projections), and independent claim 14 (turbine engine with spoke distal ends fixed to the input shaft) — are UNTESTED before the Board. The dependent claims worth mapping in any invalidity study are unchanged as issued: the hoop (claim 2), circumferentially unconnected projection ends (claim 3), hoop notches (claim 4), different circumferential profiles with projections optionally wider (claims 5–6), axial positioning of projections (claims 7–8), tangency of spokes (claim 9), and the dual-sensor-plus-controller torque determination (claim 16). A challenger gets to pick its own battleground rather than litigate a record someone else already made.

Estoppel landscape. With no IPR, there is no § 315(e)(2) estoppel attaching to anyone, and there is no petitioner whose prior-art grounds a defendant would need to avoid as "raised or reasonably could have raised." The entire universe of patents and printed publications under § 102 and § 103 remains available as IPR grounds. What does constrain a defendant is statutory, not estoppel-based: § 315(b)'s one-year bar runs from service of a complaint alleging infringement, and § 315(a)(1) bars a petitioner who first filed a civil action challenging validity (a DJ count can close the IPR door). Since no litigation was found for this patent either, a defendant served today likely still has a full one-year window. Note also that the patent dates to a 2008-10-16 filing, so PGR is unavailable (pre-first-inventor-to-file), and CBM is not a fit — this is a mechanical turbomachinery torque sensor, not a financial services business-method patent, and the CBM transitional program closed to new petitions on 2020-09-16. IPR (and ex parte reexamination, a CRU matter rather than a PTAB one) are the realistic vehicles.

Pattern signals. There are none to read. No serial petitioner, no follow-on joinder, no Unified Patents or other defensive aggregator in the chain, and no patent-owner appeal — because there has never been a trial to appeal. The patent's administrative footprint is entirely routine maintenance: 4th-year fee paid 2015-11-02, 8th-year 2019-11-01, 12th-year 2023-10-24, status Active with an adjusted expiration of 2031-01-08. The only family-side citing documents are US 7,810,402 B2 (Rolls-Royce, "Torque monitoring apparatus," priority 2008-10-29 — a closely related but distinct Rolls-Royce patent describing a piston/cylinder fluid-pressure torque sensor, not this spoke-and-projection design) and FR 3017657 B1 (Snecma, torsion disk torque measuring device). Neither is PTAB activity. The absence of IPRs on a 14-year-old, still-maintained mechanical patent owned by a single operating company is consistent with a portfolio patent that has not been asserted — an inference from the record, not proof of non-assertion.

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Recommended next steps

1. Treat this as a clean slate. No FWD exists to cite, so there is no disposition to link and no claim to describe as "dead." Do not plead or argue that claims of 8,167,538 have been canceled or narrowed — they have not.
2. Close the ODP ingest gap before relying on the negative. Pull PTAB E2E (https://ptacts.uspto.gov/) and the USPTO PTAB decisions search (https://developer.uspto.gov/ptab-web/#/search/decisions) on both 8167538 and application 12/252,407, and cross-check CourtListener (https://www.courtlistener.com/) for any appeal under 35 U.S.C. § 319.
3. If a demand letter arrives, preserve the § 315(b) window. Calendar one year from service, and do not file a DJ or other civil action challenging validity before deciding on an IPR, or § 315(a)(1) will bar the petition.
4. Build the art set from the patent's own face and analogous turbomachinery. The 13 references of record are the natural starting point — particularly US 7,665,373 (Kop-Flex, torque measuring device with redundant transmission paths), US 5,450,761 and US 5,969,269 (Kop-Flex), US 7,322,250 and US 6,981,423 (Rockwell Automation), and US 4,809,557 (Ringspann). Note the examiner never had to defend claim 1's sole structural hook — the relative axial thickness of the projections versus the spokes — so § 103 combinations targeting that dimensional relationship, plus the tangential-spoke teaching of claims 9/17, are the highest-value attack surfaces.
5. If no proceeding has appeared by the time you act, say so plainly in any opinion. The absence is itself the signal: this patent has never been stress-tested at the Board, and the strongest defensive value available is the full § 102/§ 103 art universe with no estoppel against you.

Caveat on scope: this analysis is limited to AIA trial proceedings (IPR/PGR/CBM) and related appeals. Ex parte or inter partes reexamination, district-court litigation, and ITC matters are outside the PTAB block and were addressed in the earlier sections of this report.

I'll verify the assignment record and ownership chain with targeted searches before reconstructing the timeline.

Ownership & Assignment Analysis — US 8,167,538 B2

Scope note: The chain here is a one-link chain. I have reconstructed it from the Google Patents legal-events record cross-checked against the patent document itself (which reproduces the reel/frame in the assignment citation). I could not retrieve the USPTO Assignment Center cover sheet for reel 021689/0050, so the correspondent of record is not captured — that is a documented gap, not a negative finding, and I flag it explicitly below rather than guessing a firm name.

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Inventors

Pattern check — no anomalies detected. No record indicates either inventor departed Rolls-Royce within 12 months of the 2008-10-16 filing, and no later assignment or security interest names either inventor as an assignor to a third party. The assignment being executed 13 days before the filing date (2008-10-03 vs. filing 2008-10-16) is entirely routine — employers standardly perfect title before or at filing.

Caveat stated plainly: I have no employment-verification source (no SEC 10-K personnel data, no state records) confirming either inventor worked for Rolls-Royce. Their employer is inferred from the assignment alone. Inventor-departure tracking is therefore unclear, not "not present."

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Original assignee

Rolls-Royce Corporation (Indianapolis, Indiana; assignment also lists the record owner as "ROLLS-ROYCE CORPORATION, INDIANA").

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Assignment timeline

One recorded assignment exists. There are no post-issuance transfers.

• 2008-10-03 (executed) / recorded 2008-10-16 — Reel 021689/0050
  • Conveyance: Assignment (recorded description: "ASSIGNMENT OF ASSIGNORS INTEREST"; assignor free-format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:NORRIS, CHRIS;WILKINSON, MATT)
  • Assignor: Chris Norris; Matt Wilkinson (individuals, jointly)
  • Assignee: Rolls-Royce Corporation, State of Indiana
  • Correspondent: ⚠ NOT DETERMINABLE from the sources retrieved. The Patent Assignment Search cover sheet is the only place the recording correspondent (attorney/agent) is displayed, and I could not pull the record for reel 021689/0050. No correspondent name is inferred or guessed here. Since this is the only link in the chain, the "repeat correspondent" signal cannot be assessed at all — see signal 3 below.
  • Context: Initial employment/inventor assignment — title perfection from the inventors to their corporate employer, executed pre-filing. Not an acquisition, reorg, securitization or asserter transfer.

Everything after 2008 is an administrative event, not an assignment:

No Change of Name, Security Agreement, Merger, License, Release, or Correction record appears anywhere in the chain, and no release/security interest would be expected absent a securitization — none is present.

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Timeline diagram

timeline
    title Ownership of US 8167538
    2008 : Inventors assign to Rolls-Royce Corp
         : Application 12/252407 filed
    2010 : Pre-grant publication issued
    2012 : Patent US 8167538 B2 issued
    2015 : Fourth-year maintenance fee paid
    2019 : Eighth-year maintenance fee paid
    2023 : Twelfth-year maintenance fee paid

(Event text kept punctuation-free for parser safety; app number rendered without the comma separator.)

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NPE / troll-pattern signals

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Verdict

Insufficient data

Justification (rubric call, with a substantive gloss): Under this rubric, "Insufficient data" is defined to include the case of "only the original assignment" — which is precisely this record. The assignment timeline contains exactly one entry: inventors Chris Norris and Matt Wilkinson → Rolls-Royce Corporation, executed 2008-10-03, recorded 2008-10-16 at reel 021689/0050; every subsequent legal event (2012 grant, 2015/2019/2023 maintenance fees) is administrative. Substantively, that single-entry chain points to the opposite of an NPE profile — the patent is held by an operating aerospace OEM that is actively investing in the Indianapolis plant where the disclosed hardware would be built, and is still paying 12th-year maintenance fees, so no NPE signal above is present and none of the eight signals could be affirmatively scored.

The residual "insufficient data" is procedural, not substantive: (a) I could not retrieve the correspondent of record for reel 021689/0050, which is the one data element your brief flags as the key NPE tell, and (b) no divorce between ownership and product — or absence thereof — can be proven from the sources I could reach, only strongly indicated. If a definitive clean bill is required, the next step is a direct pull of reel 021689/0050 at the USPTO Assignment Center, searching patent number 8167538 (also shown as application 12/252,407):

• https://assignmentcenter.uspto.gov/ (search by patent number 8167538)
• https://assignment.uspto.gov/patent/index.html (same underlying records)

If that pull returns only the 2008-10-16 inventor→Rolls-Royce record with no correspondent recurrence, the correct re-scored verdict would be Operating-company ownership, non-asserting — a fully vertical, uncontested chain.

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Cross-reference flags for the record

• Sibling patent: US 7,810,402 B2 — also titled "Torque monitoring apparatus," also Rolls-Royce Corporation, priority 2008-10-29 (13 days after this filing). It appears in the record as a family member citing this patent. The shared title and assignee indicate a common R&D programme at the same Indianapolis engineering group, but the two are separate applications with separate claims (the '402 claims a piston-and-cylinder fluid-pressure approach; the '538 claims the spoke/projection hub geometry). I have no evidence they share inventorship — do not assume shared inventors without an Assignment Center pull.
• No conflict detected with the earlier-generated sections: the single-family-member finding (country status: US only) and the "no litigation surfaced" finding are both consistent with a one-link assignment chain ending at the original operating assignee.

Known limitations of this analysis

1. Correspondent of record for reel 021689/0050 — not retrieved; the signal-3 call is therefore "unclear," not "not present."
2. Whether any Rolls-Royce engine in commerce actually practices claims 1/10/14 — not verified; inferred from technical context only.
3. SEC filings were not reviewed for a parent-level patent securitization or intra-group IP transfer that might be recorded in a separate USPTO reel under an affiliate (e.g., Rolls-Royce plc). The Google Patents legal-events feed shows none against this patent number, but an affiliate-level blanket assignment naming thousands of patents could exist without appearing in this patent's feed.

I'll verify the citation set and pull detail on the key references.

Now let me pull detail on the remaining cited references.

Prior-Art Analysis — US 8,167,538 B2 ("Torque monitoring apparatus")

0. Identifier confirmation and two flagged contradictions

Confirmed: the number 8167538 resolves to a single document — US 8,167,538 B2, App. No. 12/252,407, "Torque monitoring apparatus," Norris & Wilkinson, Rolls-Royce Corporation, filed 2008-10-16, granted 2012-05-01. I found no similar-number document that legitimately claims this identity (the Brazilian registry entries "8167537/8167538/8167539" surfaced again and are not patent numbers). I did not reach USPTO PatentCenter/PAIR directly — the bibliographic and citation data below come from the USPTO-derived record, and the citation list is authoritative because it is reproduced in the patent document itself.

Contradiction 1 — date. My tool-environment date is 2026-09-30; this task's header states April 26, 2026. I proceed on the basis that both post-date the patent's 2023 maintenance-fee payment and therefore do not affect legal status, but flag the discrepancy as instructed.

Contradiction 2 — citation-marker ambiguity. Per the record as fetched, only US 7,665,373 B2 carries the asterisk that denotes cited by examiner. The other twelve carry no visible marker. I therefore cannot tell you which of the twelve were examiner citations versus third-party (IDS) submissions. Treat "cited by examiner" below as applying only to US 7,665,373.

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1. Analytical framework (why the §102 answer is "none," and precisely where the exposure sits)

US 8,167,538 was filed 2008-10-16, so pre-AIA 35 U.S.C. §102 governs. The §102(b) critical date is 2007-10-16; a reference with a publication date on or after that date must be carried in via §102(e) on its US filing date.

Anticipation under §102 is an all-elements, single-reference test. For a dependent claim, the reference must disclose the dependent limitation and every limitation of the independent claim from which it depends. That is decisive here, because the independent claims turn on very specific limitations:

• Claim 1: hub along an axis between first and second ends + spokes radially outward to distal ends + projections axially spaced from the spokes + the projections are thinner along the axis than the spokes (a single dimensional limitation — and the only limitation distinguishing the projection set from the spoke set).
• Claim 10: connect input and output shafts through the apparatus + transmit torque through only the first set of radial projections.
• Claim 14: a turbine engine + spokes whose distal ends are fixed to the input shaft + projections thinner along the axis than the spokes.

None of the thirteen references discloses the "thinner-along-the-axis" limitation, and none discloses the claim 10 "torque through only the first set" feature — the two Kop-Flex hub-and-spoke references teach the opposite (torque through both spoke sets). Consequently no reference anticipates claim 1, 10, or 14, and therefore none anticipates any dependent claim either. The realistic attack vector is §103, and the two Kop-Flex references are where it lives.

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2. Master table of the thirteen cited references

Note on #1: the record gives US 4,809,557 a priority date of 1986-04-05 (matching a German priority), while a secondary index lists the US application as filed 1987-04-01. Either way the issue date of 1989-03-07 is far outside the critical date, so the discrepancy is immaterial to §102 — but I am flagging it rather than silently normalizing it. Inventors: Maurer, Timtner, Reig.

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3. Reference-by-reference: description and §102 exposure

1. US 4,809,557 A — Ringspann Albrecht Maurer KG, "Method and apparatus for measuring torque" (issued 1989-03-07)

Description: Two axially adjacent rings (2, 3) are secured rotation-fixed to a shaft (1) at their remote ends so the intervening axial length can be exploited to develop maximum relative rotation. Facing axial ends of the rings carry a plurality of circumferentially distributed notches (2a, 3a); a radially extending knife body (6) is supported between opposed notches, so torque-induced relative rotation rotates the knife body about a radial axis. That rotation is translated into an amplified axial movement via toggle levers set at an acute angle to the circumferential direction, and the axial position is measured — optionally non-contacting, with indicators/wedges on a common transducer ring that can be read from outside the machine. Toggle levers may be milled as inclined slits in a thin-walled cylinder, i.e., integral with the two rotating parts.
§102 exposure: None. Lacks a hub with two sets of radial projections, lacks spokes to distal ends, and lacks the thinner-projection limitation — so claim 1 is not met; the device is interposed around a single shaft rather than connecting an input and output shaft, so claim 10 is not met; no turbine engine, so claim 14 is not met. Its disclosure of deliberately amplified relative movement between two parts read from outside is relevant to the claim 16 sensing scheme, but only via §103.

2. US 5,067,354 A — Kyowa Electronic Instruments, "Torque transducer and torque measuring device" (issued 1991-11-26)

Description: Drive-side and load-side rotating members (flat plates or cylindrical bodies) each carry first slits (73a), paired with second slits (74a) in adjacent stationary members (74). Photosensors (75/76) detect the degree of opening between the two slits; the opening cycles from zero to maximum as the disc rotates. Torque is derived by comparing the phase of the periodic signal at the drive side with that at the load side; zero torsion gives zero relative phase difference. A memory/switching-circuit arrangement handles the low-speed and stationary cases. Slit angular interval is deliberately varied (sector/rectangular slits on concentric-circle divisions) to shape the signal.
§102 exposure: None. No hub/spoke/projection geometry at all — claim 1 fails immediately, and claims 10 and 14 fail with it. Closest relevant teaching is the two-sensor/phase-comparison → torque determination, i.e., the claim 16 concept, and the deliberate variation of feature width/interval for detectability, which touches the claim 5–6 theme. §103 material only.

3. US 5,228,349 A — Simmonds Precision Products, "Composite power shaft with intrinsic parameter measurability" (issued 1993-07-20)

Description: A non-ferromagnetic composite tubular power shaft contains an internally disposed reference sleeve. A first ferromagnetic gear-like element (spaced teeth) moves with the shaft and a second moves with the sleeve; the two sets of teeth are intermeshed at one axial location. A variable-reluctance (or optical Faraday) sensor external to the shaft reads the sensible formations through the composite wall, so no through-hole or aperture is needed in the load-carrying shaft. Relative movement of the two intermeshed formations varies in accord with torque; the same sensing structure yields speed, and torque × speed yields horsepower.
§102 exposure: None for claims 1, 10 and 14. There is no hub, no radially outward spokes, no projections and no thickness differential. It is nonetheless squarely relevant to (i) claim 3 — the sensible formations are discrete, circumferentially unconnected gear teeth, and (ii) claim 16 — an external non-contact sensor plus interpretation of relative position. Its central teaching — put the sensible structure where the magnetic sensing can reach it without weakening the torque path — is a §103 lever against the claim 10 "outside the torque path" concept.

4. US 5,450,761 A — Kop-Flex, Inc., "Torque meter" (issued 1995-09-19; inventors Zilberman et al.)

Description: A hollow/solid shaft carries a reference exciter wheel (40) attached by welding/bolting (42), and a cantilevered composite sleeve (44) fixed near one end (48, via press-fit plus adhesive plus at least two mechanical fasteners) with its other end free of the shaft. A second exciter ring (50) is secured to the interior free end of the sleeve. Teeth of the two rings are intermeshed, as in U.S. 3,548,649. Two reluctance sensors (22, 24) are 180° apart to compensate for non-arcuate relative displacement caused by shaft bending/misalignment; a non-conductive fiberglass-epoxy ring (54) overlies the teeth so carbon-epoxy conductivity does not impair pickup. The point of the cantilever is to avoid a bearing supporting the free end.
§102 exposure: None. No hub, no two sets of radial projections of differing axial thickness. Highly relevant, however, to claim 11 (minimizing the thickness/non-structural character of the second set) and to the claim 10 concept of a sensing element mounted on a member that is not a primary torque path — this is arguably the clearest antecedent in the record for "the sensing set need not carry load."

5. US 5,969,269 A — Kop-Flex, Inc., "Flexible coupling with torque measuring and detecting device" (issued 1999-10-19; Munyon et al.) — closest structural art

Description: The torque meter (20) is a wheel/disk having two sets of spokes: spokes (34) of a first disk (36) have outer ends integral with an outer peripheral rim (38) and inner ends integral with a hub (40) common to both disks; a second disk (42) has an array of spokes (44) that, unstressed, are in substantial axial alignment with spokes (34) and terminate at a separate outer rim (46). "In essence, the torque element consists of two spoke wheels connected with a tubular member at their inner section. Torque is applied at the outer periphery of one wheel, traverses the tapered spoke sections and is transmitted to the rest of the coupling through the periphery of the second wheel." Spokes narrow from the inner base to a reduced-thickness portion (52) and then widen toward the rim, giving circumferential softness with uniform stress distribution. Bore holes (48, 50) near the outer ends allow attachment to coupling flanges (18, 22). Exciter teeth (56, 58) on rims (46, 38) are read by detectors (60) — including a redundant second sensor — and reflective patches on spokes support photo-detection of relative shifting of the rims.
§102 exposure: This is the most dangerous reference, and yet it still does not anticipate:

• Claim 1 — NOT anticipated. Discloses a hub (40), a first plurality of spokes (34) extending radially outward to distal ends at rim 38, and a second plurality of spoke/projection members (44) spaced along the axis and extending radially outward to distal ends at rim 46. It fails the final limitation: the two sets are expressly "substantially identical," with no disclosure that the axially spaced set is thinner along the axis. Missing one limitation ⇒ no anticipation.
• Claim 10 — NOT anticipated, and contrary teaching. Torque is transmitted through both sets (rim 38 → spokes 34 → hub 40 → spokes 44 → rim 46). The reference affirmatively routes load through both spoke sets, which is the opposite of "transmit torque through only the first set."
• Claim 14 — NOT anticipated. No turbine engine.
• However: the hub + two axially spaced spoke sets + rim + external tooth/sensor detection combination maps remarkably well onto the structural genus of claims 1/14, and the narrowing/tapering spoke geometry touches the claim 5–6 circumferential-profile theme. This is the primary §103 reference — combine with US 5,450,761 or US 5,228,349 for the "the non-torque-carrying set can be made minimal" teaching.

6. US 6,439,067 B1 — Curtis Instruments, "Shaft sensor assembly for angular velocity, torque, and power" (issued 2002-08-27)

Description (verification gap — see §5): A shaft-mounted sensor assembly deriving angular velocity, torque and power; the genre is coded rings/sleeves with pickups and computation of torque from the differential/phase relationship between two sensors.
§102 exposure: None as to claims 1, 10, 14. Best characterized as background art for the claim 16 controller-and-two-sensors architecture. I was unable to verify the disclosure text against the full document before exhausting my search budget; treat the description as title/assignee-level and unverified.

7. US 6,679,126 B2 — Control Devices, "System and method for measuring torque using filtration of light to detect angular displacement of a pair of wheels" (issued 2004-01-20)

Description: Optical torque measurement in which light is filtered and the angular displacement of a pair of wheels is detected, the displacement being proportional to transmitted torque.
§102 exposure: None. A pair of wheels with optical displacement detection is remote from a hub carrying radial spokes and thinner axially-spaced projections. Relevant only to the claim 16 sensing concept (two patterned members, relative angular position → torque) and as evidence that non-contacting optical sensing of relative twist was well known. Content verified only at the title/abstract level.

8. US 6,782,766 B2 — Gastops Ltd., "Apparatus for detecting torque, axial position and axial alignment of a rotating shaft" (issued 2004-08-31)

Description: An apparatus detecting not only torque but also axial position and axial alignment of a shaft — i.e., it recognizes that torque readings from an axial-gap sensor are contaminated by shaft axial displacement and misalignment, and provides for detecting those separately.
§102 exposure: None. No hub/spoke/projection geometry. Its significance is defensive/contextual: it is the art that supplies the reason a designer would put the sensed feature outside the torque path and would want the projection set small — feeding a §103 motivation argument, not a §102 case.

9. US 6,981,423 B1 — Rockwell Automation Technologies, "System and method for sensing torque on a rotating shaft" (issued 2006-01-03) and

10. US 7,322,250 B1 — Rockwell Automation Technologies, same title (issued 2008-01-29)

Description: These two are the same disclosure family (the earlier filed 2002-04-09 and issued 2006; the later filed the same day and issued after the critical date). They concern non-contact torque sensing on a rotating shaft, of the patterned-surface/pickup-and-signal-processing genre.
§102 exposure: None as to claims 1/10/14 — neither has a hub, radial spokes, nor axially-spaced projections of differential thickness. US 7,322,250 requires a §102(e) route (its 2008-01-29 issue date post-dates the 2007-10-16 critical date) with an effective date of its 2002-04-09 filing; the materially identical US 6,981,423 was §102(b) art long before. Content verified at the title/abstract level only.

11. US 7,092,504 B2 — Lord Corporation, "Method and system for measuring torque" (issued 2006-08-22)

Description (medium confidence): Magnetoelastic torque measurement — a sensor assembly positioned proximate a magnetoelastic region of a torque-carrying member, deriving torque from the magnetic response to stress.
§102 exposure: None. Physically a different sensing modality (material-property based rather than geometric-relative-displacement based), and it lacks the hub/spoke/projection architecture entirely. Background art at most.

12. US 7,392,714 B2 — GM Global Technology Operations, "Torque monitoring system and method of monitoring engine torque" (issued 2008-07-01)

Description (medium confidence): An engine torque monitoring system and method — engine-level torque determination, in the estimation/parameter-based genre applicable to an internal combustion or turbine installation.
§102 exposure: None. It shares only the word "torque monitoring" with the patent. It is nominally relevant to the claim 14/16 environment (an engine in which a torque value is monitored and delivered to a controller), but it discloses nothing of the coupling geometry. Like US 7,322,250, it needs a §102(e) route (filing 2005-12-02) because it issued after the critical date — and I should flag that I could not check whether its pre-grant publication landed before 2007-10-16, which would give it a clean §102(b) date. That check remains open.

13. US 7,665,373 B2 — Kop-Flex Inc. (Sakers & Meier), "Torque measuring device with redundant torque transmission paths and fail-safe mechanism" (filed 2008-06-18; published as US 2009/0314103 A1; issued 2010-02-23) — the only examiner-marked reference

Description (full text verified): A one-piece "powerwheel" (34) having a central hub (41); a first rim (42) with a first set of spokes (38) radially extending between hub and rim; a second rim (48) spaced apart from the first with a second set of spokes (40) radially extending between hub and rim, the second set axially spaced apart from the first; tapered spoke walls (60/62, 64/66) converging to a minimum cross-section to permit relative torsional movement. A first tubular portion (52) and flange (32) attach the drive side; a second tubular portion (54) and flange (33) attach the driven side. Two ferromagnetic indicators (35, 36) with axially extending, circumferentially spaced, interleaved teeth (72, 78) are shrink-fitted onto flanges (44, 50); sensor(s) (104) detect tooth presence/absence and a controller (106) computes torque from the changed spacing of teeth 72 relative to 78, with a display (108). Above a predetermined torque, pins (92) in oversized bores (98) engage to add a redundant load path so transient torques bypass the spokes. Normal torque path: flange 32 → tubular 52 → rim 42 → spokes 38 → hub 41 → spokes 40 → rim 48 → tubular 54 → flange 33.
§102 exposure:

• Claim 1 — NOT anticipated. It discloses the hub and two axially spaced sets of radial members, but the axially spaced set is a full torque-carrying second set of spokes, not a set of projections made thinner than the spokes; and the actual sensing projections (indicator teeth 72/78) are annular tooth bands mounted on the rims/flanges, not members "extending radially outward from said hub to respective distal ends." It expressly requires hub and pin to transfer load simultaneously when torque exceeds the threshold (claim 11 of '373), the opposite of the claim 1 geometry's implication.
• Claim 10 — NOT anticipated, contrary teaching. Torque traverses both spoke sets in normal operation.
• Claim 14 — NOT anticipated. Not a turbine engine; and its two spoke sets are symmetric, not thicker/thinner.
• Closest call is claim 16: sensor (104) + controller (106) determining torque "based on the relative positions" of two indicator structures is very close to claim 16's two-sensor/controller limitation. But because claim 16 depends from claim 14, the reference must also disclose the turbine engine and the thinner-projection limitation — it does not.
  Timing note: as §102(e) art its effective date is 2008-06-18, roughly four months before 8,167,538's filing. Whether it predates the Norris/Wilkinson date of invention is not something I can establish from the record; if the applicant could not swear behind it, it is available as prior art. That is likely why the examiner cited it.

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4. Ranked relevance, and the §102 bottom line

Tier 1 — decisive art (hub + two axially spaced radial sets):

1. US 5,969,269 (Kop-Flex, 1999) — closest structural match; anticipates nothing, but supplies every claim 1 element except the axial-thickness differential.
2. US 7,665,373 (Kop-Flex, §102(e) 2008-06-18) — same architecture as a one-piece coupling, plus the interleaved-teeth sensor/controller arrangement; also anticipates nothing, but directly targets claims 1/16 conceptually.

Tier 2 — supplies the "sensed set need not carry load / can be minimal" teaching:
3. US 5,450,761 (cantilevered, free-ended sleeve carries the sensing wheel).
4. US 5,228,349 (sensing formations in a non-load-carrying internal sleeve; unconnected discrete teeth).
5. US 4,809,557 (two relatively twisting parts, non-contacting external readout of relative position).

Tier 3 — sensing/processing concepts (claims 5–6, 16):
6. US 5,067,354; 7. US 6,679,126; 8. US 6,782,766.

Tier 4 — peripheral/background:
9. US 6,439,067; 10. US 6,981,423; 11. US 7,322,250; 12. US 7,092,504; 13. US 7,392,714.

Bottom line on §102: No cited reference anticipates any claim of US 8,167,538. Because claims 2–9 depend from claim 1, claims 11–13 depend from claim 10, and claims 15–20 depend from claim 14, and because no reference discloses the thinner-along-the-axis limitation (claims 1 and 14) or the torque through only the first set limitation (claim 10), there is no §102 anticipation of any dependent claim either. The vulnerability of this patent lies in §103 combinations of Tier 1 with Tier 2 — specifically: take the common-hub/two-axially-spaced-spoke-sets coupling of US 5,969,269, make the non-load-bearing set thin and non-structural as taught by US 5,450,761 or US 5,228,349, and read relative displacement with the sensor/controller arrangement of US 7,665,373 or US 5,067,354.

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5. Not prior art — do not cite these as such

• US 7,810,402 B2 (Rolls-Royce Corporation, "Torque monitoring apparatus"), which appears under "Families Citing this family," has a priority date of 2008-10-29 — thirteen days after 8,167,538's filing date. It is a later, related Rolls-Royce filing (a citing/family document), not prior art against this patent. If earlier work in this analysis treated it as prior art, that was an error.
• FR 3,017,657 B1 (Snecma, priority 2014-02-19) is also a later citing document, not prior art.

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6. Explicit verification gaps (please treat as open, not resolved)

1. I did not query USPTO PatentCenter/PAIR directly. Bibliographic data and the citation list come from the patent record; the citation list itself is authoritative because it is printed in the document.
2. Search budget exhausted mid-research. I obtained verified full-text detail for US 4,809,557, US 5,067,354, US 5,228,349, US 5,450,761, US 5,969,269 and US 7,665,373. The descriptions for US 6,439,067, US 6,679,126, US 6,782,766, US 6,981,423, US 7,322,250, US 7,092,504 and US 7,392,714 are at title/assignee level only and are unverified; none of them changes the §102 bottom line, but any of them could contain a tangential teaching useful to a §103 argument, and item 12 (GM) in particular should be re-checked against its full text before it is dismissed.
3. Examiner vs. third-party citation markers could be confirmed for only US 7,665,373 (asterisk = examiner). The remaining twelve are unmarked in the record I retrieved.
4. US 4,809,557's US filing date is reported inconsistently (1986-04-05 vs 1987-04-01) across sources; immaterial to the §102 analysis given the 1989 issue date, but unresolved.
5. US 7,392,714's pre-grant publication date was not established; if it published before 2007-10-16 it is §102(b) art rather than §102(e) art. Purely a category refinement — it does not affect the anticipation conclusion.
6. Whether US 7,665,373 predates the Norris/Wilkinson date of invention (as opposed to the 2008-10-16 filing date) cannot be determined from the record; under pre-AIA §102(e) that determines its availability, and it is the one reference where the answer could matter.

Grounding URLs used this session: https://patents.google.com/patent/[US4809557A](/patent/US4809557A)/en · https://patents.google.com/patent/[US5067354A](/patent/US5067354A)/en · https://patents.google.com/patent/[US5228349A](/patent/US5228349A) · https://patents.google.com/patent/[US5450761A](/patent/US5450761A)/en · https://patentimages.storage.googleapis.com/bc/0a/32/5242af0781a10f/US5969269.pdf · https://patents.google.com/patent/US7665373 · https://patentimages.storage.googleapis.com/a4/f8/af/60b838656169b4/US7665373.pdf · https://patents.justia.com/patent/[7665373](/patent/7665373)

I'll research the cited prior art references so the obviousness analysis is grounded in what each reference actually discloses.

Let me research the remaining examiner-cited references.

Obviousness Analysis — U.S. Patent No. 8,167,538 B2

"Torque monitoring apparatus" (Norris & Wilkinson; Rolls-Royce Corporation)

Analytical date: April 26, 2026
Statute applied: Pre-AIA 35 U.S.C. § 103(a) (application filed 2008-10-16, before the 2013-03-16 AIA cutoff)
Prior art source: The 13 references listed in the "Patent Citations" table of the patent record (all marked cited by examiner), plus the "Family citing" entry US 7,810,402 B2.

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1. Scope of the analysis and evidentiary caveats

Two honesty flags before the merits:

(a) These are the examiner's own references. Every reference analyzed below was before the examiner during prosecution of the '538 application. The claims issued over them. That means a § 103 challenge on this record cannot succeed merely by showing that each element appears somewhere in the art; it must show that the specific limitation that carried the allowance — the dimensional relationship "said plurality of projections are thinner along said axis than said plurality of spokes" (claim 1) — was an obvious design choice rather than a patentable one. This is where the analysis lives or dies.

(b) Verification depth varies by reference. I retrieved and read the full text/figures discussions for US 5,969,269 (Munyon), US 7,665,373 / US 2009/0314103 (Sakers), US 6,782,766 (Parkinson), US 5,450,761 (Kop-Flex), and portions of US 4,809,557 (Ringspann). For the remaining citations — US 5,067,354, US 5,228,349, US 6,439,067, US 6,679,126, US 6,981,423, US 7,322,250, US 7,093,504, US 7,392,714 — my search budget was exhausted (the tool returned a step limit) and I am relying on title, assignee, filing date, and classification only. Where I characterize those references, I say so explicitly, and any combination resting on them should be re-verified against the full texts before being asserted.

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2. Level of ordinary skill in the art (POSITA)

A bachelor's degree in mechanical or aerospace engineering, or equivalent, plus 2–5 years of experience designing rotating machinery, shaft couplings, or torque-measurement instrumentation. This is a predictable mechanical-design art: the artisan works with well-understood beam/spoke elasticity equations (torsional stiffness ∝ axial thickness), standard sensor-target design rules (target width versus sensor resolution), and established driveline practice. Under KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398 (2007), predictable arts with a finite set of design options are especially susceptible to § 103 rejection.

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3. The claims at issue

The critical observation: claim 1 is nearly a purely geometric claim over the prior art. It recites no sensor, no controller, no load path, no hoop, and no functional relationship. It differs from the closest art by a single relative dimension.

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4. The prior-art landscape

Note on US 7,665,373's status as prior art. Its U.S. filing (App. 12/141,210, Jun 18, 2008) predates the '538 filing date, and it published as US 2009/0314103 A1 on Dec 17, 2009. It therefore qualifies as pre-AIA § 102(e) art as of 2008-06-18, and § 102(e) art is available for § 103. Because Kop-Flex and Rolls-Royce are not common owners, the § 103(c) exception does not apply. This is a real, citable reference, not an anachronism.

Note on US 7,810,402. The record lists this Rolls-Royce patent as "family citing this family," but its priority (2008-10-29) and publication (2010-10-12) both postdate the '538 filing. It is not prior art to '538 and is relevant only as a same-family/same-assignee sibling — a potential obviousness-type double-patenting consideration if the two are commonly owned, not a § 103 reference.

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5. Primary combination — Claim 1

5.1 The combination

US 5,969,269 (Munyon) as primary, in view of one or more of US 7,665,373 (Sakers), US 5,450,761 (Kop-Flex), and/or US 4,809,557 (Ringspann).

5.2 Element-by-element mapping

5.3 Filling the single gap — and why it was obvious

(a) The secondary art teaches thin, axially-spaced, non-load-bearing radial projections used purely as sensor targets. US 5,450,761 discloses a thin exciter wheel whose teeth interleave with the teeth of a second ring carried on a cantilevered sleeve — a sleeve that, by construction, transmits no torque and exists only to carry a sensing feature. That is precisely the '538 arrangement's function: a set of thin radial projections sitting in the axial shadow of the load-carrying spokes, present to be detected. US 7,665,373 similarly discloses indicators in the form of thin, circumferentially-spaced, axially-extending ferromagnetic teeth (72, 78) mounted on a powerwheel structure that already has two axially-spaced spoke sets, with a sensor 104 and controller 106 reading relative tooth position to output torque.

(b) '269 itself supplies the motivation by stating the very problem the '538 patent claims to solve. The '538 specification frames the invention entirely as an axial-compactness improvement ("The exemplary torque monitoring devices can be more axially-compact than prior art torque monitoring devices"). But '269 already frames its own objective in identical terms: its selective material placement in the spokes "allows for a compact and light weight torque sensing device," and its background criticizes prior devices that "increase the weight of the coupling by a significant amount and have adverse effects on the system rotor dynamics." An artisan seeking to shrink the axial envelope and reduce rotating mass of the '269 device has a direct, reference-supplied incentive to thin the elements that are doing no structural work — which in the '538 architecture is exactly the second, sensing-only array.

(c) The thickness variable is result-effective and its adjustment is a routine engineering optimization. Torsional stiffness scales with axial thickness; detectability requires only enough target cross-section to be sensed. Once the artisan decides which array carries torque (the spokes) and which merely presents a detectable feature (the projections), setting the non-structural array thinner is the first and most obvious thing a POSITA does — it reduces axial length and mass at zero cost to load capacity. This is the classic "obvious design choice / mere optimization of a predictable variable" situation.

(d) The prior art already varies spoke cross-section freely. '269 expressly describes spokes that "narrow[] from its inner base adjacent hub 40 to a reduced thickness portion 52 intermediate its ends and then thickens or widens gradually." The reference is teaching the artisan to shape spoke cross-section as a design parameter. Nothing in '269 criticizes, discredits, or disparages a second array of lesser axial thickness. There is no teaching away.

(e) '557 adds integral formation and angle-of-attack teaching. Ringspann teaches that the levers "may be produced such that they are integral with the two rotating parts… for example by milling suitably inclined slits in a thin-walled cylinder" (→ claims 9, 17, 20) and that the levers are arranged "at an acute angle to the circumferential direction" (→ the tangent-spoke concept of claims 9/17).

5.4 Alternative primary reference

Claim 1 is at least as vulnerable with US 7,665,373 (Sakers) as primary: a one-piece hub/spokes/rims powerwheel (→ claim 20), two axially-spaced spoke sets on a common hub (→ claim 1), thin interleaved indicator teeth (→ "projections"), sensors + controller (→ claim 16), and a teaching of a second set of elements that carries no load below a predetermined torque (→ the claim 10 functional concept). Only the "thinner along said axis" relative dimension needs supplementation, and it is supplied by '761 or by the artisan's optimization as in (c) above.

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6. Dependent claims

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7. Claims 10–13 (method) and 14–20 (turbine engine)

Claim 10 — "transmitting torque through only the first set of radial projections"

This is the functional counterpart of the geometry, and the art teaches both halves:

• '373 is the closest. In its first mode of operation, torque is transferred "through a first load path including the first set of spokes, the hub portion and the second set of spokes" while "no load is transferred through pins 92." The reference thus expressly teaches deliberately designing a set of radial/axial features that carry no torque during normal operation and exist only to support measurement and to serve as a reserve path.
• '761 teaches an even cleaner analogue: a cantilevered sleeve whose free end carries an exciter ring but transmits no torque, the torque path running directly through the shaft and the welded exciter wheel.

Combining '373's or '761's "sensing elements out of the load path" teaching with '269's hub-with-two-radial-array architecture yields claim 10 without invention. The motivation is stated in the art itself: keeping sensing features out of the load path decouples sensor-geometry design from structural requirements, allowing the projections to be made thin (see § 5.3(c)).

Claim 14 — turbine engine

• "Input shaft rotatable about an axis; output shaft rotatable about the axis": '766 expressly describes the drive shaft as coupled to "a turbo shaft engine," with a driven shaft coupled to a load.
• "Spokes… distal ends fixed to said input shaft": '269's rim-to-flange bolting (bores 48, 50 to flanges 18, 22); '761's exciter wheel "attached as by welding, bolting or the like"; the '538 specification itself describes the spoke ends as welded to the input shaft via a hoop.
• "Projections thinner along said axis than the spokes": as § 5.3.

Claims 16 and 18–20 in the turbine-engine context

As tabulated in § 6. Claim 16 in particular is the weakest claim in the patent: a dual-sensor/controller torque computation is squarely disclosed in '766 and '373.

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8. Motivation to combine — articulated under KSR

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9. The patentee's best counter-arguments, and their strength

1. "The prior art requires both spoke sets to carry torque; it does not suggest removing one from the torque path." — Moderate strength for claim 10; weak for claim 1. Claim 1 recites no load path at all, so this argument cannot save the independent apparatus claim. It also fails on its own terms because '373 (no load through pins 92 in the first mode) and '761 (cantilevered, torque-transparent sleeve carrying an exciter ring) affirmatively teach non-load-bearing sensing features.

2. "'269 teaches the two sets are substantially identical; making them dissimilar teaches away." — Weak. In re Fulton / In re Gurley require the reference to criticize, discredit, or otherwise discourage the modification. '269 contains no such statement, and its tapered spokes show the artisan that spoke cross-section is a free design variable.

3. "Axial compactness was a recognized, long-felt but unmet need." — Weak on this record. The patent's own specification concedes the advantage is realized by "forming a first set of radial projections or spokes thicker along the axis of rotation than a second set" — i.e., the objective is achieved by an ordinary stiffness/mass trade-off, and no evidence of failed prior attempts or unexpected results has been presented in the record summarized here. Absent secondary-considerations evidence (nexus, unexpected results, commercial success), this argument does not overcome the prima facie case.

4. "The examiner considered all these references and allowed the claims." — Procedural, not substantive. That the same art was of record cuts against re-litigating with identical references, but it does not immunize the claims: the examiner's allowance appears to rest on the "thinner" limitation, and the argument above is precisely that this limitation is an obvious optimization in a predictable art.

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10. Bottom line

Claim 1 is very likely obvious under pre-AIA § 103(a) over US 5,969,269 (Munyon) in view of US 7,665,373 / US 2009/0314103 (Sakers) and/or US 5,450,761 (Kop-Flex) and/or US 4,809,557 (Ringspann). The combination requires adding exactly one relative dimension to the '269 disclosure, that dimension is the classic design choice of thinning a non-structural member, and both '269 and '373 articulate the very compactness/weight objectives that supply the motivation.

Claim 16 (dual sensors + controller) is the most exposed claim in the patent, being squarely disclosed by US 6,782,766 (claims 18–21) and US 7,665,373 ([0027]: sensor 104 → controller 106 → display 108).

Claim 10 is obvious over US 7,665,373, whose first mode of operation expressly transmits load through the spoke/powerwheel path while a second set of features carries none.

Claim 20 is obvious over US 7,665,373's express "one-piece coupling" claim and US 4,809,557's integral milling teaching.

Weakest link for a challenger: the "different circumferential width" and tangent-spoke dependents (claims 5–6, 9, 17) require secondary references ('766, '761, '269's soft-in-circumference teaching), and the method claim 10 requires the challenger to accept the '373 pins as "radial projections." A determined patentee could build a non-trivial argument on that substitution, though it would not rescue claim 1.

Confidence and residual uncertainty. I am confident in the mappings for '269, '373, '766, '761, and '557, which I read directly. I am not confident in, and have not relied on, the eight references I could only identify by title (US 5,067,354, 5,228,349, 6,439,067, 6,679,126, 6,981,423, 7,322,250, 7,093,504, 7,392,714) — my tooling hit a step limit before I could retrieve their texts. Any formal validity opinion should (i) confirm those eight against the prior-art database, (ii) confirm that US 2009/0314103 is valid § 102(e) art notwithstanding the post-filing publication date, and (iii) apply the secondary-considerations record, which is not reflected in the sources summarized here.