US 10168236

I'll run several targeted searches to verify the patent's current status and check for any CAFC or litigation activity.

Let me check for any PTAB, litigation, or Federal Circuit activity involving this specific patent.

Verification and scope note

I searched for the specific identifier 10168236 and did not accept adjacent numbers (e.g., EP 10168236.7 from an unrelated Syngenta agrochemical filing, or the Indian application 10688/DELNP/2012, which surfaced as false positives). Findings:

• Authoritative source located: Google Patents US10168236B2 and the USPTO/patent-images PDF (US010168236B2), both matching the identifier literally.
• No CAFC 2026 docket activity found for this patent. I could not locate any Federal Circuit appeal, oral-argument listing, or 2026 docket entry naming 10,168,236. I also found no PTAB/IPR proceeding referencing it.
• Important disambiguation: Searches for "Safran" litigation returned B/E Aerospace v. Safran Cabin (C.D. Cal. 2:19-cv-01480; PTAB IPR2022-00749). That case concerns Safran's aircraft lavatory patents (e.g., U.S. 9,365,292) — it is not related to 10,168,236 and must not be conflated with it.
• I cannot access USPTO Patent Center / CAFC docket systems directly; absence of docket hits reflects search limitations as well as genuine absence. Treat "no litigation found" as provisional.

Bibliographic summary (US 10,168,236 B2)

Literal-identifier caveats (not corrected): Google Patents lists the inventor as "Gilles La Gouellec" in the header but "LE GOUELLEC" in the assignment record. The priority table oddly shows "FR1251011" with priority date 2012-02-03, and the description states FR 1362037 "was filed on Feb. 12, 2013," whereas the priority table gives 2013-12-03. These inconsistencies are reproduced as-is.

Abstract (verbatim)

"The present invention relates to a torque-measurement device for a turbine engine shaft (1) including a proof body (7) capable of being mounted on the shaft, characterized in that the proof body (7) forms a mounting for at least one acoustic-wave strain gauge (20) and is magnetized such as to allow the torque to be measured by magnetostrictive effect. The invention also relates to a method for calibrating the torque-measurement system including a first step of calibrating said device… by applying reference torques to the shaft with the device and by establishing a rule regarding the relationship between the strain measured by said strain gauge and the actual torque applied, a step of mounting the shaft with the device inside the turbine engine together with placement of the magnetostrictive measurement system, the calibration of the first step being optionally reset with the engine stopped, and a step of establishing a calibration rule regarding the relationship between the torque measured by magnetostrictive effect and the reference torque provided by the strain gauges."

Note the abstract says "proof body," while all claims say "test piece."

Independent claims in plain language

Claim 1 — the device (independent). Three functional elements combined on one mountable body:

1. A test piece that (a) can be mounted on the turbine-engine shaft, (b) is capable of being magnetised, and (c) acts as the support/mounting for at least one surface acoustic wave (SAW) strain gauge.
2. Magnetostrictive torque-measuring means — sensors that pick up the change in magnetic permeability of the magnetised test piece as it is strained.
3. Calibration means for the magnetostrictive measurement, able to establish a calibration law relating the magnetostrictive torque reading to a reference torque supplied by the SAW strain gauge(s).

The inventive core is the combination: a single magnetised carrier that is simultaneously the SAW-gauge substrate and the magnetostrictive sensing element, so the SAW gauge can serve as an in-situ reference to calibrate the magnetostrictive measurement.

Claim 10 — the calibration method (references claim 1). Steps:

1. Establish, outside the shaft, a law between the strain measured by the SAW gauge(s) and the actual applied torque;
2. Mount the device on the shaft; and
3. Establish a calibration law between the torque measured by magnetostrictive effect and the reference torque given by the SAW gauge(s).

⚠️ Literal reading point: claim 10 recites "outside the shaft," whereas the abstract and description say the first calibration is done "outside the engine" / "outside of the engine." These are different scopes and the claim text controls.

Claim 7 ("Turbine engine shaft, comprising a measuring device according to claim 1") is a different statutory category but is formally dependent on claim 1; claims 2–6, 9 and 11 are dependent. Claim 9 adds the system elements (stator-mounted sensors opposite the test piece, fixed receiving antenna, signal-processing unit), and claim 11 adds a jaw-tooth connection at the flange end (claim 11 depends from claim 8, which in turn depends from claim 7).

Uncertainty flags

• Docket status: I have no authoritative confirmation of any 2026 CAFC or district-court activity involving 10,168,236. My searches were inconclusive on this point rather than affirmatively negative.
• Maintenance-fee currency: The 4th-year fee is confirmed paid; whether the 8th-year fee has been paid on time as of April 2026 is not verified — check USPTO Patent Center directly.
• "Expiration 2035-08-17" is a Google Patents status assumption, not a legal conclusion (consistent with 20 years from the 2014-12-02 PCT filing plus adjustment).

Sources: https://patents.google.com/patent/US10168236B2/en ; https://patentimages.storage.googleapis.com/06/2f/c8/68d498a18c4ccb/US10168236.pdf

I'll search for litigation involving US patent 10168236.

Let me search more specifically for litigation records and the patent holder's enforcement activity.

Litigation Search Results for U.S. Patent No. 10,168,236

No litigation involving U.S. Patent No. 10,168,236 has been identified.

What the patent is

• Patent: U.S. 10,168,236 B2 — "Torque-measurement device for a turbomachine shaft"
• Application: US 15/100,838 (PCT/FR2014/053138)
• Assignee: Safran Aircraft Engines SAS (originally SNECMA)
• Inventors: Augustin Curlier; Gilles Le Gouellec; Alexis Kunakovitch
• Priority: FR 1362037 (Dec. 3, 2013) and FR 1451011 (Feb. 10, 2014)
• Grant date: Jan. 1, 2019; status: Active, adjusted expiration Aug. 17, 2035
• Subject matter: A magnetized tubular "test piece" mounted on a turbine-engine shaft that carries one or more surface acoustic wave (SAW) strain gauges (claims 1, 2, 7, 9, 10). It is a mechanical measurement device, not a software/financial-method patent, and its owner is a large operating aerospace company (Safran) rather than a non-practicing entity — factors that make it an unlikely litigation target or assertion vehicle.

Litigation search performed

I searched for the patent number, its title, and its assignee across patent-litigation sources (Unified Patents litigation data, CourtListener, CAFC/PTAB-related documents, and general litigation reporting). As instructed, I looked specifically for the number 10,168,236 and did not credit similar-number hits.

Findings:

• No district court complaint, CAFC appeal, ITC investigation, or PTAB trial (IPR/PGR/CBM) naming U.S. 10,168,236 as a patent-in-suit was located.
• The patent's own record shows no litigation events — only routine prosecution and assignment events, plus a 2022 maintenance-fee payment (4th year, large entity). The "Cited By" references are later patents citing it as prior art (e.g., RTX Corporation phonic-wheel patents, a Russian utility model), not litigation.
• Search hits that mentioned "Safran" in a litigation context were unrelated to this patent and should not be treated as hits:
  • B/E Aerospace, Inc. v. Safran Cabin Inc., et al., No. 2:19-cv-01480-MWF-AFM (C.D. Cal.) — asserted U.S. Patents 9,365,292 and 9,857,742 (aircraft lavatory/seat technology). These are different patents and different technology from the '236 patent.
  • Snecma v. Turbine Engine Components Technologies Corp., No. 6:07-cv-01354 (N.D.N.Y.) — a contract action from 2007, unrelated.
  • The National Retirement Fund v. Safran SA, No. 24-cv-09902 (S.D.N.Y.) — an ERISA withdrawal-liability case, unrelated.

Caveats

• I could not directly query PACER or a complete Unified Patents litigation database in this session, so this result reflects the available web-accessible records rather than an exhaustive docket-by-docket check. Absence of hits in these sources is strong but not absolute proof that no case exists.
• If you need a definitive confirmation, the authoritative steps would be: (1) a PACER/RECAP party-and-patent search for "10,168,236," (2) the Unified Patents litigation portal, and (3) a USPTO PTAB (P-TACTS) search for the patent number. Based on the public records reviewed here, however, the honest answer is: no known litigation.

I'll verify the "no PTAB activity" default with targeted searches before reporting.

Let me run a couple more targeted checks before finalizing.

Proceedings overview

Total AIA trial proceedings on file against US 10,168,236: zero. The structured PTAB record supplied with this task (USPTO Open Data Portal, most recent ingest) returns no IPR, PGR, or CBM proceeding for this patent, and my independent web searches for 10168236 / 10,168,236 combined with PTAB and Federal Circuit terms surfaced no petition, institution decision, FWD, termination, or appeal. Breakdown by status is therefore N/A: 0 active, 0 claims invalidated, 0 claims sustained, 0 settled, 0 institution denials. Bottom-line defensive posture: all 11 claims (1–11) remain untested and presumptively valid at the PTAB. There is no IPR record you can cite to argue the patent is narrowed or weakened — a defendant here must build its own invalidity case from scratch rather than piggybacking on a prior petitioner's work product.

⚠️ Caveat on sourcing: I found no proceeding, and I also found no affirmative document stating that none exists — I am reporting the absence of evidence as "no PTAB activity on file," consistent with the ODP block and search results. If you need a certified negative, pull the Patent Center "PTAB trials" tab and the PTAB E2E docket directly for application 15/100,838.

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No proceedings to report

There is no IPR/PGR/CBM case number to place under a ### {PROCEEDING_NUMBER} — {Petitioner} v. {Patent Owner} heading. Per the task constraints, I will not invent one. For completeness, the claim-level status this leaves you with:

• Claims 1–11: UNTESTED. No claim of the '236 patent has been canceled, confirmed, or construed by the Board in any AIA trial.
• Claim 1 (device: magnetizable test piece supporting a SAW strain gauge + magnetostrictive measuring means + magnetostrictive calibration means), claims 2–6 (tubular test piece, friction fixing, perpendicular contact surface, jaw teeth, cylindrical antenna), claims 7–8 and 11 (turbine engine shaft with the device / radial flange), claim 9 (system with stator sensor, fixed antenna, processing unit) and claim 10 (calibration method) all stand as issued.

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Strategic summary

Claim status. US 10,168,236 issued 2019-01-01 with an adjusted expiration of 2035-08-17, and its maintenance-fee record (4th-year fee paid 2022-06-23, large entity) shows the owner is actively maintaining it. Because no AIA trial has ever been instituted, the patent has not been narrowed at the PTAB — the full claim set 1–11 is intact. Any narrowing that exists lives only in the prosecution history (the application was filed 2014-12-02 as PCT/FR2014/053138, published as US 2016/0299019 A1, claiming priority to FR 1362037 of 2013-12-03 and FR 1451011 of 2014-02-10). The claim language itself is notably functional in places — claim 1's "means for calibrating... capable of establishing a calibration law" and claim 9's "unit for processing the signal" invite § 112(f) construction fights, but that is a district-court/Board argument you would have to raise first.

Estoppel landscape. § 315(e)(2) estoppel is irrelevant here — there is no prior petitioner and no FWD, so no ground is foreclosed to anyone. Every prior-art ground, whether or not it was before the examiner, remains available. The 26 references cited on the face of the patent (e.g., US 5,052,232; US 4,895,492; US 4,806,466; US 4,890,598; US 5,351,555; US 6,098,468; US 6,517,508; US 8,844,375; and the FR 2919050 / FR 1362037 family references) are the examiner's own work product and thus fair game as starting points — though art already of record tends to be less potent than fresh prior art. Non-patent literature of record includes Sachs et al., "Remote sensing using quartz sensors," Proc. SPIE vol. 2718 (1996) — the examiner clearly knew the SAW-torque-measurement space.

Pattern signals. None of the classic patterns are present: no serial petitioner, no patent-owner PTAB appeal (there is no FWD to appeal), no defensive aggregator (no Unified Patents, RPX, etc.) in the chain. I found no Federal Circuit appeal touching this patent. Note also the strategic context: the assignee is Safran Aircraft Engines SAS (originally SNECMA), a major operating aerospace manufacturer, not a non-practicing entity. This is a defensive/procurement-side patent in a portfolio sense — it is the kind of patent that gets asserted in supply-chain or competitor disputes rather than in a troll campaign. Practically, that means (a) the opponent you are likely up against is well-capitalized and will defend it hard, and (b) the "absence of IPRs is itself a signal" heuristic cuts the other way here — Safran patents on engine hardware are rarely targeted by mass filers, so the clean PTAB record is weak evidence about validity strength.

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Recommended next steps

1. Stop looking for an IPR record — there isn't one. Do not draft a defense premised on a canceled claim; claims 1–11 are all live. Any argument that "the PTAB killed claim X" would be sanctionable misrepresentation.
2. Verify the negative yourself before relying on it: USPTO Patent Center (https://patentcenter.uspto.gov — search application 15/100,838, "PTAB Trials" tab) and PTAB E2E (https://ptab.uspto.gov) for the patent number. Cross-check CourtListener (https://www.courtlistener.com) for any CAFC docket naming Safran and the '236 patent. My searches found nothing in any of these channels, but the ODP ingest note explicitly warns that recent filings may lag.
3. Build invalidity from primary sources. Because no estoppel applies, your best leverage is new prior art, not the examiner-cited references. The claim 1 combination (magnetized proof body + SAW strain gauge on the same part + magnetostrictive measurement + calibration law linking them) is the crux; the art to hunt is pre-2013-12-03 references combining magnetostrictive collar torque sensing (the Garshelis / Magnetoelastic Devices line, US 5,351,555 and its progeny) with SAW/resonant torque transducers (the Senseor FR 2919050 line and Kalinin's "Resonant SAW torque sensor" work). I have not verified that any single reference or combination actually discloses claim 1's calibration-means limitation — that is a search question, not a conclusion I can assert.
4. If you want a PTAB vehicle, there is a clear runway: the patent is within IPR/PGR eligibility for a party not estopped. File your own petition well inside the one-year § 315(b) bar from service of any complaint, and be aware of the March 2025 interim discretionary-denial/workload-management guidance — expect a Fintiv-style briefing fight if there is parallel district-court litigation.
5. Watch the family. The corresponding WO publication is WO 2015/082835 A1 (counterpart status: "Ceased"), and French parents FR 3014196 B1 and FR 3017458 B1 exist. Foreign prosecution/opposition history (EP, FR) can be a source of prior art and claim-scope arguments that never surfaced in the US file — worth mining before you draft grounds.

I'll reconstruct the assignment record from the authoritative patent text first, then cross-check against live sources.

The patent text gives me three recorded events with reel/frame numbers. Let me try to surface the correspondent of record.

Ownership & Assignment Analysis — US 10,168,236 B2

Patent: Torque-measurement device for a turbomachine shaft
Application: US 15/100,838 (national phase of PCT/FR2014/053138)
Granted: 2019-01-01 | Priority: 2013-12-03 | Adjusted expiry: 2035-08-17

Sourcing caveat up front. The three recorded assignments below are taken verbatim from the Google Patents legal-events feed for this patent, which reproduces the USPTO Assignment Center reel/frame records. The correspondent of record (the filing attorney/agent) was not exposed in any source I could reach. I could not retrieve it from Assignment Center, Google Patents, Espacenet INPADOC, or open-web mirrors. I am not going to guess at a correspondent name. See Signal 3 below.

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Inventors

All three are named on the French priority filings FR1362037 (2013-12-03) and FR1451011 (2014-02-10), both Snecma filings, and each signed the US assignment between 2015-12-12 and 2015-12-15 (per the assignment abstract text: SIGNING DATES FROM 20151212 TO 20151215).

Pattern check — no anomaly. The 2-year gap between the Dec-2013 priority filing and the Dec-2015 signature is ordinary housekeeping for a PCT national-phase entry: the US application was filed in the names of the inventors (PCT/FR2014/053138 was filed 2014-12-02 by Snecma), and the assignment confirming corporate ownership was recorded ~6 months later on 2016-06-02. There is no evidence of inventors departing the assignee within 12 months of filing, and no inventor appears as an assignor or assignee in any later link of the chain. There is nothing here resembling a pre-fire-sale inventor exodus.

Data-quality note (identifiers taken literally, not corrected): the Google Patents "Applications Claiming Priority" table also lists FR1251011 / 2012-02-03, which does not reconcile with FR1451011 / 2014-02-10 appearing elsewhere in the same table. I am flagging it as a record artifact rather than resolving it.

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Original assignee

SNECMA — recorded as the assignee on grant, renamed SAFRAN AIRCRAFT ENGINES SAS (assignment log shows the name-change effective 2016-08-03). Both names are the same legal entity; Safran Aircraft Engines is the current assignee.

• Primary line of business: design, manufacture and support of aircraft and helicopter turbine engines (commercial and military turbofans, turboprops, turboshafts). Part of Safran S.A. (Euronext Paris: SAF), a large publicly traded aerospace group. The patent itself is directed to a torque-measurement device for a turboprop power shaft and to the calibration of that measurement — squarely Safran's product line (the specification discusses the inability to use a brake bench "because the hubs of the propellers cannot be accessed").
• Does it ship a product embodying the claims? Yes, in the ordinary sense: Safran Aircraft Engines builds and supports the turbine engines into which this shaft torque-measurement device is integrated. See the corresponding case, I have no independent product-teardown confirmation that a specific production engine ships the claimed proof-body-with-SAW-gauge-plus-magnetised-strut combination, and I say so rather than overclaim.
• Current status: operating. No bankruptcy, no dissolution, no acquisition. Maintenance fee (4th year, large entity) paid 2022-06-23; status listed as Active.

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Assignment timeline

Three recorded events. All three are household/administrative in nature. Nothing in the chain is a transfer to a third party.

• 2015-12-12 → 2015-12-15 (executed, per signature block) / recorded 2016-06-02 — Reel 038783/0890

  • Conveyance: Assignment (ASSIGNMENT OF ASSIGNORS INTEREST)
  • Assignor: Augustin Curlier; Gilles Le Gouellec; Alexis Kunakovitch
  • Assignee: SNECMA (France)
  • Correspondent: not retrievable from the sources consulted — I will not fabricate one. The Google Patents legal-events entry for this reel/frame carries the assignor/assignee/signing-date fields but not the recording correspondent, and I could not reach Assignment Center's per-record correspondent field.
  • Context: routine confirmatory inventor-to-employer assignment for a PCT national-phase entry; the operating company was already the substantive owner via the priority filings.

• effective 2016-08-03 / recorded 2018-05-23 — Reel 046479/0807

  • Conveyance: Change of Name (not an acquisition — same legal entity, new corporate name)
  • Assignor: SNECMA
  • Assignee: SAFRAN AIRCRAFT ENGINES (France)
  • Correspondent: not retrievable. One short clause on recurrence: the reel/frame pair itself recurs portfolio-wide, not the attorney — Espacenet's INPADOC record for the utterly unrelated SNECMA patent US 8,197,213 B2 ("Turboprop including a set of adjustable-pitch blades") carries the identical entry 2018/05/23 … CHANGE OF NAME;ASSIGNOR:SNECMA;REEL/FRAME:046479/0807. That confirms this was a bulk, portfolio-wide name-change recordation, not a per-patent transaction. It is not a correspondent-recurrence signal.
  • Context: internal corporate reorg / change of name only — the 2016 SNECMA → Safran Aircraft Engines rebrand.

• effective 2016-08-03 / recorded 2018-08-24 — Reel 046939/0336

  • Conveyance: Corrective Assignment
  • Assignor: SNECMA
  • Assignee: SAFRAN AIRCRAFT ENGINES
  • Correspondent: not retrievable.
  • Context: correction only. Recorded text: "CORRECTIVE ASSIGNMENT TO CORRECT THE COVER SHEET TO REMOVE APPLICATION NOS. 10250419, 10786507, 10786409, 12416418, 12531115, 12996294, 12094637 12416422 PREVIOUSLY RECORDED ON REEL 046479 FRAME 0807." This is the USPTO-side cleanup of an over-inclusive cover sheet on the bulk name-change filing — an administrative fix, not a transfer.

Bottom line for this section: there are no post-issuance ownership transfers. The only substantive assignment is 038783/0890 (inventors → SNECMA). After that, the record is a name change and a correction of that name change. The original assignee's successor still owns the patent.

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Timeline diagram

timeline
    title Ownership of US 10168236
    2013 : Priority filing FR1362037 by Snecma
    2014 : PCT FR2014 053138 filed by Snecma
    2015 : Inventors sign assignment to SNECMA
    2016 : Assignment recorded at USPTO
         : SNECMA renamed Safran Aircraft Engines
    2018 : Change of name recorded
         : Corrective assignment recorded
    2019 : Patent granted

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NPE / troll-pattern signals

1. Shell-entity transfer — Not present. No assignee anywhere in the chain carries an "IP / Patents / Licensing / Holdings / Ventures" suffix. Reels 038783/0890, 046479/0807 and 046939/0336 all run to SNECMA / Safran Aircraft Engines — a French operating aerospace manufacturer. No LLC, no registered-agent address, no single-purpose vehicle.

2. Known asserter in the chain — Not present. Neither SNECMA nor Safran Aircraft Engines appears on any of the asserter lists referenced (Acacia, Marathon, Intellectual Ventures, IPNav, Wi-LAN, Mosaid/Conversant, Vringo, Pendrell, Innovatio, MPHJ, Lumen View, Round Rock, Document Generation Corp, Erich Spangenberg entities), and no such entity appears anywhere in the reel/frame record. No Unified Patents or RPX high-frequency-plaintiff match.

3. Repeat correspondent across the chain — Unclear / not assessable. This is the one signal I cannot close out, and I want to be precise about why rather than assert a negative I did not verify. The correspondent of record is not exposed by Google Patents legal events, by the Espacenet INPADOC record, or by any open-web mirror I reached before the search budget was exhausted. Because there is only one substantive assignment in this chain (038783/0890) and it is an inventor-to-employer filing, the recurrence test — "same attorney on multiple links" — has almost no scope to fire here even if the name were known. Recording was almost certainly handled by in-house legal (Safran Legal Department, 10 Allée du Brévent, Courcouronnes) or by outside US counsel on the PCT national-phase entry. I mark this unclear on evidence, not on suspicion.

4. Cascading transfers — Not present. Three recorded events over ~27 months, but they collapse to a single transaction plus its administration: one inventor assignment (2016-06-02), one bulk name change (2018-05-23), one correction to that same name change (2018-08-24). No chained LLCs, no shared correspondent addresses, no common principals. The recurring reel/frame pair on US 8,197,213 confirms the 2018 filings were portfolio-wide housekeeping rather than patent-specific.

5. Pre-litigation transfer — Not present. I found no infringement litigation naming US 10,168,236 in the sources provided. There is therefore no transfer to time against. The last ownership event (2018-08-24) predates grant (2019-01-01) by four months and is a correction, not an assertion-enabling transfer.

6. Bankruptcy fire-sale — Not present. Safran S.A. is a going concern; no Chapter 7/11, no patent sale in proceedings, no 10-K/8-K disclosure of a portfolio disposition. The 4th-year maintenance fee was paid 2022-06-23 by a large entity.

7. Privateering — Not present. No operating-company-to-NPE transfer exists to characterise as privateering. The patent never leaves the Safran corporate family.

8. Defensive aggregator (anti-NPE) — Not present. The chain does not terminate at RPX, AST, LOT Network, Unified Patents, or OIN. It terminates at Safran Aircraft Engines, an operating manufacturer. The inverse indicator is what is actually observable: the patent is being cited by competitor work in the same space — five RTX (Raytheon Technologies) phonic-wheel/turbine-engine patents from 2023–2025 (US 12,078,073; US 12,123,311; US 12,258,869; US 12,281,584; and US 12,123,311's family), plus a 2021 Russian utility model — i.e., it is prior art in an actively engineered field, which is what one expects of a practicing operating company's patent.

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Verdict

Operating-company assertion — selected with an explicit caveat, because the taxonomy does not cleanly fit.

Justification: reels 038783/0890 (recorded 2016-06-02, inventors → SNECMA), 046479/0807 (recorded 2018-05-23, SNECMA → Safran Aircraft Engines, change of name only) and 046939/0336 (recorded 2018-08-24, correction to the same name change) describe a single operating-company ownership chain with zero NPE signals firing — no shell entity, no listed asserter, no cascade, no bankruptcy, no privateering, no defensive-aggregator termination. Safran Aircraft Engines is a large, active aerospace manufacturer and is the sole and continuing owner.

The caveat: the "assertion" half of the label is not supported. I found no infringement suit naming this patent. What the record proves is operating-company ownership by a product-shipping manufacturer, not assertion. If your taxonomy allowed a "operating company — non-asserting, no NPE pattern" bucket, that would be the literal description; on the forced menu, this patent belongs on the operating-company branch and not on the NPE branch. Nothing in the assignment record supports an NPE/troll classification at any confidence level.

Verify at: USPTO Assignment Center (search patent 10168236) · USPTO Patent Assignment Search · Google Patents legal events

I'll research US patent 10168236 and its cited prior art references.

Let me research the specific prior art references cited in this patent.

Prior-Art Analysis — US 10,168,236 B2

Patent under review: US 10,168,236 B2 — "Torque-measurement device for a turbomachine shaft"

• Application No. US 15/100,838 (PCT/FR2014/053138, WO 2015/082835 A1)
• Priority date: 2013-12-03 (FR 1362037); also claims FR 1451011 (2014-02-10)
• Filed: 2014-12-02 | Granted / published: 2019-01-01
• Inventors: Augustin Curlier, Gilles Le Gouellec (listed as "LA GOUELLEC" in the fetched record), Alexis Kunakovitch
• Original assignee: SNECMA → now Safran Aircraft Engines SAS
• Source: https://patents.google.com/patent/US10168236/en

Methodology / confidence note. The reference list below is taken directly from the "References Cited" and "Patent Citations" sections of the Google Patents record for US 10,168,236 (26–28 patent citations plus 2 non-patent citations). I am reporting each reference's citation data (number, assignee, title, priority/publication dates) exactly as listed. Characterizations of a reference's content are drawn from its listed title and, where available, from the subject patent's own discussion of it. Because I could not open and read every cited document's full specification within this session, the § 102 mapping below should be treated as a preliminary relevance assessment (based on titles + the patent's background), not a verbatim claim-chart. Any final anticipation conclusion requires reading each reference's claims and specification.

Also note: the fetched record shows two different dates for the same FR priority document in the family table (FR 1362037 is variously shown as "2012-02-03" and "2013-12-03," and FR 1251011 as "2012-02-03"). I am using the front-page priority date of 2013-12-03 because that is what the "Priority date" and "Prior art date" fields state and what the description ("FR 1362037, which was filed on Feb. 12, 2013") is consistent with. I flag the inconsistency rather than silently correcting it.

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1. The claims at issue (grouped for § 102 mapping)

• Claim 1 — the independent device claim: (a) test piece mountable on the shaft that is capable of being magnetised and forms a support for at least one SAW strain gauge; (b) magnetostrictive torque-measuring means (sensors capturing variation in magnetic permeability of the magnetised test piece); and (c) calibration means establishing a calibration law between the magnetostrictive-torque measurement and a reference torque given by the SAW gauge.
• Claims 2–6 — structural refinements: tubular test piece / gauge on the interior wall / antenna / two axially-remote fixing elements (2); friction fixing element (3); perpendicular contact surface (4); complementary teeth / jaw teeth (5); cylindrical antenna (6).
• Claims 7–8, 11 — turbine-engine shaft (and shaft with radial flange / jaw-tooth connection at other end) comprising the device.
• Claim 9 — system: stator-side sensors for the magnetostrictive measurement + fixed antenna receiving the SAW signals + signal-processing unit.
• Claim 10 — calibration method: (i) establish SAW-strain-vs-applied-torque law outside the shaft/engine; (ii) mount device on the shaft; (iii) establish a calibration law between the magnetostrictive torque and the reference torque from the SAW gauge.

The novelty crux of claim 1 is the physical and functional combination on one common test piece of (1) a SAW gauge used as a calibration reference and (2) a magnetised body read out magnetostrictively — with calibration transferred from the SAW measurement to the magnetostrictive measurement. As the patent states, this lets the magnetostrictive measurement "be calibrated once installed on the engine… by means of the measurement carried out previously using the acoustic wave strain gauge(s) as instrumentation."

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2. Patent citations (as listed on the front page of US 10,168,236)

Dates given as priority date → publication date, per the record.

Non-patent citation

• Sachs, Thomas, et al., "Remote sensing using quartz sensors," Proc. SPIE, Vol. 2718 (May 30, 1996), pp. 47–58. — Remote interrogation of resonant (quartz/SAW-type) strain sensors. Relevant to the SAW remote-interrogation/telemetry element of claims 1–2 and 9 (rotating gauge + fixed antenna), but it is a single-measurement reference; it does not disclose the magnetostrictive + SAW calibration combination.

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3. References cited in the specification (important, though not all appear as "examined" citations)

The patent body expressly identifies these as the closest starting points — these are the references the skilled person would weigh most heavily under § 102/§ 103:

• US 2007/0030134 A1 (named in the description as "US-A1-2007/030134"; the Stoneridge "sensor system including a magnetized shaft" family — cf. WO 2007/048143 A3). Discloses a shaft with an active magnetised region and magnetic field sensors producing a torque output. This maps to the magnetostrictive element of claim 1(b), but it discloses no SAW strain gauge and no SAW-derived calibration law → it does not anticipate claims 1, 9, or 10.
• U.S. Pat. No. 5,052,232 (Garshelis, "Magnetoelastic torque transducer"). Magnetise two shaft portions polarized oppositely in the circumferential direction; field detectors around the shaft. Maps to claim 1(b) only → no anticipation of the asserted combination.
• FR 2,919,050 (Senseor; US 8,393,224 B2 counterpart, "Stress gauge having an acoustic resonant structure and sensor for at least one physical parameter using such stress gauge"). Discloses a SAW/resonant acoustic strain gauge and its sensor. Maps to the SAW element of claims 1(a), 2 → no anticipation of the combined calibration feature.
• FR 1362037 (the applicant's own earlier application, FR 3,014,196 B1 / US counterpart, "Device for mounting strain gauges on a rotary shaft"). Applicant-admitted prior development; the present claim 1 differs by adding the magnetostrictive measurement and the SAW-based calibration law.
• WO 2009/141261 (Turbomeca) and WO 2011/144874 (Snecma) — interleaved phonic-wheel torque methods; described as the prior baseline the invention seeks to improve.

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4. Bottom line — most relevant prior art and § 102 posture

No single cited reference anticipates the independent claims. The examiner's citations fall into three independent buckets, each of which is anticipation-relevant only to elements of the claims:

1. Magnetostrictive / magnetoelastic torque sensing — US 3,939,448; US 4,760,745; US 4,896,544; US 5,351,555; US 5,386,733; WO 1996/026420; US 6,047,605; US 6,098,468; US 6,516,508; US 7,401,531; US 7,127,797; plus US 5,052,232 and US 2007/0030134 from the background → support the magnetostrictive measuring means of claim 1(b).
2. Surface-acoustic-wave / resonant strain gauges and remote interrogation — US 4,078,186; FR 2,919,050 / US 8,393,224; the Sachs SPIE paper → support the SAW gauge, antenna, and telemetry elements of claims 1(a), 2, and 9.
3. Shaft-mounted wireless instrumentation / attachment — US 5,952,762; US 7,256,505; US 7,127,797 → support mounting/telemetry aspects of claims 1, 8, 9.

The distinguishing feature that no cited reference discloses — and which therefore survives § 102 — is the co-location on a single common (magnetisable, SAW-supporting) test piece of both measurement modalities plus a calibration means that establishes the calibration law for the magnetostrictive measurement using the SAW gauge's reference torque (claim 1(c), and the corresponding calibration method of claim 10, and the system of claim 9).

Where the greatest § 103 (obviousness) exposure lies: a combination of a Garshelis-type magnetostrictive sensor (e.g., US 5,351,555 / US 4,896,544 / US 5,052,232 / US 2007/0030134) with a SAW strain-gauge reference (FR 2,919,050 / the Sachs paper) — the examiner would argue it would have been obvious to use a known accurate reference gauge to calibrate a known magnetostrictive sensor. The patent's likely rebuttal is the unexpected benefit and the specific structural integration (single test piece → single engine installation, avoiding the double-mounting tolerance problem admitted for standalone magnetostrictive systems), which is the stated inventive purpose.

Caveats

• The § 102 mapping above is preliminary: I relied on the citation data and titles from the Google Patents record, plus the subject patent's own characterization, rather than a full-text, claim-by-claim read of all 26–28 documents. A definitive anticipation opinion requires examining each reference's claims and disclosure.
• US 9,856,967 B2 (priority 2014-04-11) post-dates this patent's 2013-12-03 priority date and therefore is not § 102 prior art on its listed priority date. US 8,844,375 B2 (priority 2012-12-19, published 2014-09-30) is only potentially § 102(a)(2) art because it was effectively filed before the subject filing.
• The family table in the fetched record contains an internal date inconsistency for FR 1362037 / FR 1251011 (shown as both 2012-02-03 and 2013-12-03). I used the front-page priority date of 2013-12-03 and flag the discrepancy rather than correcting it.

Primary source: https://patents.google.com/patent/US10168236/en (Google Patents, US 10,168,236 B2).

I'll verify the key prior-art references before building the § 103 grounds.

Let me verify a few more references central to the obviousness analysis.

Obviousness Analysis — 35 U.S.C. § 103

Patent: US 10,168,236 B2 — "Torque-measurement device for a turbomachine shaft"
Claimed priority: 2013-12-03 (FR 1362037) / 2014-02-10 (FR 1451011) | PCT filed: 2014-12-02 | Granted: 2019-01-01
Assignee: Safran Aircraft Engines SAS (orig. SNECMA) | Claims: 11

This section builds on — and does not repeat — the Prior-Art, PTAB, Litigation and Assignment sections above. Those sections established (i) what the examiner cited, (ii) that nothing on the face of the patent anticipates claim 1, and (iii) that no AIA trial has ever been instituted, so no claim is narrowed and no § 315(e) estoppel applies. Obviousness is therefore the operative battleground, and every ground below is available to a first-moving challenger.

Statutory framework: The application was filed 2014-12-02, after 16 March 2013. The AIA versions of §§ 102/103 apply. That matters for two references flagged below.

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1. The person having ordinary skill in the art (PHOSITA)

A PHOSITA here is a mechanical/aerospace (or electromechanical) engineer with a bachelor's degree and roughly 2–5 years of experience in rotating-machinery instrumentation — specifically shaft torque sensing, strain gauges, non-contact magnetoelastic transducers, and RF/SAW telemetry for rotating components — or a master's degree with less experience. This is a mature, crowded, cross-disciplinary field: the patent itself cites 26–28 patent references and 2 non-patent references spanning 1945–2014, and the examiner cited the Sachs SPIE paper on remote quartz/SAW sensing as early as 1996 — evidence that the SAW‑torque-measurement combination was already within the ordinary artisan's working knowledge.

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2. What actually has to be shown

Claim 1 is a three-element combination (see the plain-language breakdown in the Patent Summary section above). For § 103 the question is not whether any one reference discloses the whole thing — it does not — but whether the differences between the claimed invention and the prior art are such that the subject matter as a whole would have been obvious. The four differences to be bridged are:

None of D1–D4 is a technical "how." They are architectural and procedural choices in a field the applicant itself concedes was well-populated.

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3. Ground 1 (primary) — Claim 1, and claims 2–6, 7, 8, 9, 11 by dependency

References:

• [Garshelis-1] US 5,052,232 A (Garshelis; Magnetoelastic torque transducer; priority 1989-05-18; granted 1991-10-01) — cited on the face of the '236 patent.
• [Garshelis-2] US 5,351,555 A / US 4,896,544 A / US 6,047,605 A / WO 1996/026420 A1 (Magnetoelastic Devices / Garshelis) — cited on the face of the '236 patent.
• [Senseor] FR 2,919,050 B1 (Senseor) and its US counterpart US 8,393,224 B2 — Stress gauge having an acoustic resonant structure… — cited on the face of the '236 patent and named in the '236 specification.
• [Stoneridge] US 8,191,431 B2 (Hedayat/Poirier; Stoneridge Control Devices; granted 2012-06-05) and its published parent US 2007/0089539 A1 — Sensor system including a magnetized shaft.
• [Kalinin-2007] Kalinin, Lohr, Leigh & Bown, "Application of passive SAW resonant sensors to contactless measurement of the output engine torque in passenger cars," Proc. IEEE Int'l Frequency Control Symposium, pp. 499–504 (May–June 2007).

3.1 Element-by-element mapping

3.2 Motivation to combine

(a) The applicant's own specification supplies the motivation. Under KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398 (2007) and MPEP 2144, a statement in the specification identifying a known problem is strong evidence of a reason to solve it. The '236 specification:

• identifies the magnetostrictive technique's admitted defect: "the disadvantage of needing to be mounted on the engine twice because firstly the stator elements and secondly the rotor elements … have to be mounted separately. Due to the mounting tolerances, the measuring system is thus in a different mechanical configuration on the engine than during a calibration outside the engine"; and
• identifies the SAW technique's virtue: components "located in the definitive spatial configuration thereof before the installation thereof in the engine," so that "[a] calibration which is carried out outside the engine is thus disrupted very little by the installation in the engine."

Reading those two admissions side by side, the claimed invention is the arithmetic sum of a known problem and a known solution: put both modalities on one pre-assembled, pre-mounted test piece so there is only one mechanical configuration. That is the classic KSR fact pattern, and it is the applicant's own framing.

(b) Co-location is the natural engineering choice, not an inventive leap. Both modalities measure the same physical quantity (torsional strain) in the same axial region of the same shaft. Co-locating the reference with the measurand is the standard way to eliminate error from differing load paths, temperature, and stiffness. There is no technical obstacle: Garshelis-1 already claims a magnetisable region on the surface of the torqued member, and a SAW gauge bonded to that region requires nothing more than a flat (the '236 patent's own "flat spots 75" / "recesses 75" are ordinary surface preparation).

(c) Substituting a co-mounted SAW gauge for the brake bench is substitution of a known reference for a known reference. The admitted prior art calibrates the torque measurement against a brake bench reference torque. A PHOSITA seeking to eliminate the bench — which the specification says is "particularly costly or impossible to use" where "the hubs of the propellers cannot be accessed when the engine is assembled" — would replace the external reference with an on-board, pre-calibrated reference. Kalinin-2007 already teaches that a SAW element on a drivetrain component yields a calibrated torque signal. Predictable result, known technique, same device improved in the same way → KSR rationales (A) and (C).

(d) Stoneridge supplies the specific reference-and-correct architecture. US 8,191,431 is not merely analogous art; it is squarely directed to the problem the '236 patent confronts (drift/aging/zero-offset of a magnetostrictive torque signal, and validating "proper magnetization, installation, and/or calibration"). It teaches exactly the structural topology of claim 1(c): a second, co-located sensor whose output is substantially torque-independent is used as the yardstick against which the primary torque output is adjusted. The only difference is that Stoneridge's second sensor is a fluxgate coil, while the '236 patent uses a SAW gauge. That is a substitution of one known reference-transducer for another, chosen from the same field, for the same purpose, with predictable results — an expressly enumerated KSR ground.

(e) The system and shaft claims follow. Claim 9's "sensor fixed on a stator part opposite the test piece … a fixed antenna … and a unit for processing the signal" is precisely the Stoneridge housing-and-coil architecture (its "housing 3602 that is slipped over the shaft," fluxgate coils, magnetometers, torque circuitry) combined with the SAW interrogator of Senseor/Sachs. Claim 7 (shaft comprising the device) and claim 8's (flange-borne axial retention) require nothing more than Garshelis's ring/collar abutting a shaft shoulder, plus the '236 specification's own admitted precedent of "bearing axially against the flange."

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4. Ground 2 — Claim 1 via the Stoneridge magnetized shaft line + Senseor/Kalinin

References: [Stoneridge-2] US 2007/0030134 A1 and its confirmed family US 7,469,604 B2 / US 7,363,827 B2 / US 7,895,906 B2 (the "sensor system including a magnetized shaft" family, which the '236 specification names as the closest prior art via the designation "US-A1-2007/030134"), in view of Senseor (FR 2,919,050 / US 8,393,224) and Kalinin-2007.

Mapping: Stoneridge-2 discloses a shaft having at least one magnetised active region and magnetic field sensors about the shaft producing a torque output — i.e., elements (a) in substance and (b) in full. The specification's own characterisation of this reference (see the Prior-Art section) is that it maps to the magnetostrictive element of claim 1(b). Senseor and Kalinin-2007 supply the SAW gauge element. Stoneridge's own later US 8,191,431 (Ground 1) supplies the reference-and-correct calibration.

Motivation: identical to Ground 1(a)–(d). The principal advantage is that a challenger may prefer this framing where the priority/§ 102 date of the magnetostrictive art is contested, because the Stoneridge family is dated 2005–2012 and is unambiguously § 102(a)(1) art.

⚠️ Verification limitation. My searches did not return the specification text of "US 2007/0030134 A1" itself; they returned the immediately adjacent Stoneridge publication (US 2007/0089539 A1) and the granted family members. I therefore treat the "US-A1-2007/030134" characterisation as coming from the '236 patent's own description, and I would not rely on Ground 2 without pulling the actual document. Ground 2's family-level mapping, however, is confirmed by the granted Stoneridge patents retrieved above.

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5. Ground 3 — Claim 10 (calibration method)

Claim 10 has three steps: (i) establish, outside the shaft, a law between SAW-measured strain and actual applied torque; (ii) mount the device on the shaft; (iii) establish a calibration law between the magnetostrictive torque and the SAW reference.

This is the weakest claim in the patent and the one most exposed to § 103. Note the literal drafting first: claim 10 says "outside the shaft," while the abstract/description say "outside the engine." The claim text controls, and the narrower reading disclosed-and-claimed relationship is itself an argument the patentee must reconcile.

Combination: [Admitted prior art] (brake-bench calibration of a torque measurement against a reference torque — '236 spec) + Kalinin-2007 (SAW torque sensors are "calibrated," with reported "torque and temperature calibration characteristics") + Stoneridge US 8,191,431 (adjusting a magnetostrictive torque output in response to a co-located reference signal).

Motivation: Two-step calibration — bench-calibrate a precision instrument, install the assembly, then transfer the calibration to the production sensor — is the textbook procedure for commissioning any instrumented machine. The '236 specification asserts no unexpected result from this ordering; it simply states it. Under In re Kubin and the KSR "obvious to try" line, following a known calibration protocol in its known sequence, on known hardware, is not an inventive act.

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6. Ground 4 — Dependent claims 2–6, 11 (mechanical refinement layer)

None of claims 2–6 or 11 recites a result that is more than the predictable consequence of the structure selected. No secondary-consideration nexus is apparent from the specification.

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7. Ground 5 — Claim 9 (system), including the fixed antenna and processing unit

Combination: Ground 1 or 2 + Sachs, Thomas, et al., "Remote sensing using quartz sensors," Proc. SPIE Vol. 2718, pp. 47–58 (30 May 1996) (non-patent literature of record) + Senseor US 8,436,512 B2 / FR 2,979,171 (Senseor interrogation methods) and Kalinin-2007 (RF rotary coupler for a rotating SAW element).

Mapping: Sachs and the Senseor interrogation patents disclose the interrogation system + remote passive resonator + RF antenna topology that claim 9 recites as "a fixed antenna which can receive the signals from said at least one strain gauge." Kalinin-2007 discloses the large-diameter RF rotary coupler used to read SAW elements on a rotating drivetrain part. Stoneridge US 8,191,431 supplies the stator-mounted magnetic field sensors "positioned adjacent said active region."

Motivation: Claim 9 adds no new physics. Once one decides to put a passive SAW gauge on a rotating shaft (Ground 1), remote RF interrogation via a fixed stator antenna is the only way to read it — the patentee concedes as much ("It is essential for the antenna to be electrically insulated with respect to the shaft… to communicate by means of electromagnetic waves with the interrogation system of the gauges which are located on the stator part"). Motivation is thus supplied by the function itself.

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8. § 112(f) exposure on "means for calibrating" — and what it does to the § 103 analysis

Claim 1's third element is recited in means-plus-function form: "means for calibrating … which are capable of establishing a calibration law…" Claim 9's "unit for processing the signal" is similarly functional. If construed under § 112(f):

• The corresponding structure is a general-purpose processor/microprocessor programmed to perform a curve-fit or lookup — nothing more specific is disclosed. The specification describes no algorithm.
• Under well-settled law, reciting a generic processor to perform a known data-processing function does not confer patentability, and the prior art need only disclose structure performing the claimed function. A programmed processor that computes a relationship between two sensor outputs reads directly on Stoneridge's anti-aging torque circuitry (US 8,191,431, claim 12: "maintaining a constant ratio of an amplitude of said output to said reference signal") and on Kalinin-2007's reported torque/temperature calibration characteristics.
• Tactical consequence: the broadest reasonable reading of claim 1(c) is any processor that derives a relationship between the magnetostrictive reading and the SAW reading. That breadth is a § 103 vulnerability, and a challenger should plead both the broad reading (anticipation-adjacent under 103) and the § 112(f) reading alternatively.

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9. What the patentee will argue — and how much it helps

No secondary consideration is documented in the file — no commercial-success, copying, licensing, industry-praise, or unexpected-results evidence appears in the patent or in the sources retrieved. Absent a nexus-bearing record, KSR's "predictable results" framework should control.

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10. Claim-by-claim obviousness conclusion

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11. Where the § 103 case could fail

1. No explicit "combine these two" statement. None of the retrieved references states "mount a SAW gauge on the magnetostrictive collar and use it as the calibration reference." The case rests on articulated reasoning with rational underpinning (KSR; MPEP 2143), not on an express hint. A strong patentee brief can argue hindsight reconstruction.
2. The Stoneridge reference sensor is magnetic, not SAW. Substitution of a SAW gauge for a fluxgate reference coil must be justified as a design choice with predictable results — defensible, but not automatic.
3. Diagnostic vs. calibration scope. Stoneridge's "calibration" language is largely about zero-torque offset and installation validation, not full-span transfer of a reference law. The patentee will press this distinction hard, and it is the single best foothold for distinguishing Stoneridge.
4. Applicant's maturity admission could be spun into a teaching away argument if the patentee locates evidence that the art regarded SAW-on-engine as unreliable — the specification's own words cut against them, but a skilled advocate will try.
5. § 112(f) uncertainties cut both ways; if the Board or court declines to invoke 112(f), the claim's functional breadth still aids the challenger, but the challenger loses the clean "prior art need only disclose structure" line.

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12. Reference-integrity and confidence notes

• § 102 date anomalies preserved, not corrected. Per the Prior-Art section, US 8,844,375 B2 (GE; priority 2012-12-19, published 2014-09-30) qualifies only as § 102(a)(2) art (effectively filed before the 2013-12-03 priority date). US 9,856,967 B2 (CNH; priority 2014-04-11) post-dates the priority date and is not § 103 prior art on its face. I have used neither as a primary ground. The record's internal FR 1362037 / FR 1251011 date inconsistency (2012-02-03 vs. 2013-12-03) is reproduced as-is and is not resolved.
• Unverified: the specification text of US 2007/0030134 A1 (the patent's "US-A1-2007/030134"). Ground 2 should not be filed without pulling the document. The Stoneridge family mapping (US 7,469,604; US 7,363,827; US 7,895,906; US 8,191,431) is confirmed from retrieved granted-patent text.
• Not confirmed by full-text read: US 7,256,505 (MicroStrain, shaft-mounted wireless sensing/energy harvesting) and US 2011/0193552 A1 (SRI, magnetic-encoding displacement) — characterised in the Prior-Art section from citation data only. I have not relied on either for any ground above.
• Applicant's own FR 1362037 is treated strictly as an applicant admission / evidence of the state of the art, since it shares the '236 priority date and, as a French national application, is not § 102(a)(2) art. Its use as prior art would require the priority claim for the magnetostrictive subject matter to fail, which I have not assumed.
• No litigation, no IPR, no estoppel. Consistent with the earlier sections: no § 315(e) estoppel applies, no claim is narrowed, and the 26–28 examiner-cited references plus the fresh references identified here are all available. Note the strategic asymmetry flagged earlier — the clean PTAB record for this patent is weak evidence about true validity strength, because Safran engine-hardware patents are rarely targeted by mass AIA filers.