US 11402406

I'll search for litigation/docket activity and confirm the patent's bibliographic data.

US Patent 11,402,406 B2 — Summary

Source (authoritative full text): https://patents.google.com/patent/[US11402406](/patent/US11402406)/en (fetched 2026-09-24)

1. Bibliographic data

Classification highlights: G01R 27/205 (measuring contact resistance), G01R 31/006 (testing electrical installations on road vehicles), B60L 53/16 (EV charging connectors), H01R 13/11 (resilient sockets).

2. Abstract

An evaluation method is a method for evaluating a charging connector in coolability by connecting an evaluation jig to the charging connector, the charging connector including a pair of male terminals coolable with a coolant, the evaluation jig including a pair of female terminals, the pair of female terminals being connected to the pair of male terminals in evaluating the charging connector in coolability. The method comprises: connecting the pair of female terminals to the pair of male terminals; adjusting a connection state between the male terminal and the female terminal such that contact resistance between the terminals is 0.06 mΩ or more and 0.15 mΩ or less; and after the adjusting, evaluating the coolability depending on whether the male and female terminals have a temperature of 90° C. or lower when a charging current of 400 A is supplied to the terminals for 30 minutes.

3. Plain-language overview of the independent claim (claim 1)

Claim 1 — An evaluation method for evaluating performance required for a connector by connecting a reference jig to the connector.

The claim recites four elements in sequence:

1. Setup: A connector having a pair of male terminals; a reference jig having a pair of reference terminals connectable to those male terminals. The reference terminals are connected to the male terminals.

2. Connect: Physically connect the pair of reference terminals to the pair of male terminals.

3. Adjust: Adjust the connection state between each male terminal and each reference terminal so that a resistance including the resistance at the contact portion between them is 0.06 mΩ or more and 0.15 mΩ or less.

4. Evaluate: After adjustment, judge performance by whether at least a first male terminal and its corresponding first reference terminal stay at 90 °C or lower when 400 A is supplied to each male terminal and each reference terminal for 30 minutes.

Structural limitation on the reference terminal (this is what narrows the claim relative to the original disclosure):

• each reference terminal must have a plurality of pieces spaced about a center axis, each piece extending parallel to the center axis; and
• a convex portion protruding toward the center axis from the inner surface of each piece; and
• in the adjusting step, the connection state must be adjusted using a metal band configured to attach to the plurality of pieces and to tighten them.

In everyday terms: you plug a reusable test jig's spring-finger contact terminals onto the round DC power pins of a liquid-cooled EV charging connector, then use an adjustable metal band to squeeze those fingers until the measured resistance across the pin/socket interface sits in a narrow window (0.06–0.15 mΩ). Holding that resistance constant, you run 400 A for 30 minutes and pass the connector only if the pin/socket terminals remain at or below 90 °C. Pinning the resistance to a defined band is what makes the cooling test repeatable instead of depending on how tightly the jig happens to grip.

Claim 2 (dependent) — narrows the resistance window of claim 1 to 0.08 mΩ or more and 0.1 mΩ or less.

Notable claim-drafting observation: the granted claims use broader/different terminology than the specification and abstract — "reference jig"/"reference terminals" instead of "evaluation jig"/"female terminals," and "performance required for a connector" instead of "coolability," and "resistance including a resistance at a contact portion" instead of "contact resistance." The specification also describes a "removing step" (partially cutting away the male casing's tubular wall to open an operating space) that is not recited in granted claim 1. This suggests the claims were amended during prosecution relative to the as-filed disclosure; the answer above follows the granted claims literally.

4. Litigation / CAFC docket search — result

I searched for the specific number 11402406 in connection with litigation, PTAB, and Federal Circuit activity, and found no match:

• No CAFC 2026 appeal, no district-court infringement case, and no IPR/PGR involving US 11,402,406 appeared in my search results. (The CAFC activity my searches surfaced — e.g., NantWorks v. Niantic, Network-1 v. Google, April 2026 summary — involves unrelated patents.)
• The only third-party citation activity of record on the patent page is the "Cited By" list, which consists of Toyota's own sibling filings (US 2021/0218255 A1, US 11,695,286 B2, US 12,184,104 B2) — i.e., family members, not adverse parties.

Uncertainty caveat: I do not have direct, authenticated query access to PACER, the CAFC docket, or USPTO PatentCenter from this session — only open web search. An absence of hits in my searches is not affirmative proof that no litigation or appeal exists; it means I found none and cannot confirm one way or the other. If a formal litigation/docket clearance is required, the number should be run directly against USPTO PatentCenter, PACER, and the CAFC docket.

5. Summary of the technical context (from the specification)

• The connector at issue is a liquid-cooled EV charging connector based on the ChaoJi standard, with 9 mm-diameter round DC power pins; the mating inlet has female terminals.
• The disclosure explains that contact resistance at the pin/socket interface is the dominant heat source, and that uncontrolled variation in that resistance makes coolability tests unreliable — hence the fixed resistance band.
• The specification also claims (in the original disclosure) a contact-resistance measurement convention: resistance measured between a point 4.5 mm from the male casing bottom-wall surface (on the male side) and a point 43 mm from that surface (on the female side), with point P2 chosen to sit near the boundary of the region governed by the applicable design standard. Note: this measurement-point recitation appears in the specification/original claim set but is not in granted claim 1 or 2.
• Prior art cited on the face of the patent includes JP 2019-187035 (liquid-cooled charging connector), US 2020/0282851 A1 (Tesla, liquid-cooled charging cable and connector), and US 2020/0353830 A1 (TE Connectivity Germany, electrical plug connector).

I'll search for litigation involving US patent 11402406.

Let me search additional litigation-specific sources.

Let me do a few more targeted searches to be thorough.

Summary of Findings

No litigation is known involving U.S. Patent No. 11,402,406.

I searched litigation-oriented sources (Unified Patents portal references, Docket Alarm/PTAB exhibits, CourtListener, and general web queries for the patent number, its title, and its assignee), and found no district court complaints, ITC actions, CAFC appeals, or PTAB proceedings in which US 11,402,406 is the asserted or challenged patent.

Search detail (requested fields)

Because no case exists, the fields you requested cannot be populated:

Important disambiguation note (per your strict-ID rule)

One search hit referenced an IPR2023-00148 (Apple Inc.) exhibit discussing a "U.S. Patent No. 11,246,024." I am not auto-correcting or conflating that with US 11,402,406 — these are literally different patent numbers, and 11,246,024 is unrelated to this patent.

Similarly, the numerous Toyota patent lawsuits that surfaced (e.g., Emerging Automotive LLC v. Toyota (E.D. Tex. 2:23-cv-00437); AutoNavigare v. Toyota (E.D. Tex. 2:24-cv-00439); IDT v. Toyota; Intellectual Ventures v. Toyota) involve other, unrelated patents and do not name US 11,402,406 as a patent-in-suit.

Context on the patent itself

• Patent: US 11,402,406 B2, "Evaluation method"
• Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corp.)
• Priority: 2020-01-10 (JP 2020-003138); Filed: 2020-12-09; Granted: 2022-08-02
• Family/related U.S. patents (all Toyota's own): US 2021/0215739 A1 (cont. US 17/854,919 / US 2022/0334143 A1); US 11,695,286 B2 ("Evaluation jig"); US 12,184,104 B2 ("Reference jig"); and cited-by US 2021/0218255 A1 ("Evaluation jig"). These are prosecution-family members, not adverse litigation.
• Legal status: Active; 4th-year maintenance fee paid (event dated 2026-01-21 per the Google Patents record).

Caveats on confidence

I do not have direct, authenticated access to PACER, the CAFC docket, or the Unified Patents litigation API in this session; my conclusion rests on indexed web/PTAB/docket-material results. It is possible that a very recent, low-profile, or sealed suit is not yet indexed. If you need a court-record-level confirmation, I recommend running the patent number directly through PACER (Dockets), the Unified Patents litigation caselist, Docket Navigator, or RPX Insight for US 11,402,406. Based on available evidence, however, the correct answer is that there is no known litigation involving this patent.

I'll verify the structured data with web searches before drafting.

Let me run a couple more targeted checks before concluding.

One final check on appeals and any terminated proceedings.

PTAB / AIA Trial Landscape — US 11,402,406 B2

Patent: US 11,402,406 B2 ("Evaluation method"), Toyota Jidosha Kabushiki Kaisha
Priority: 2020-01-10 (JP 2020-003138) · Filed: 2020-12-09 · Granted: 2022-08-02
Claims: 2 (claims 1–2) · Status: Active; next maintenance fee (4th year) paid 2026-01-21

Proceedings overview

There are zero AIA trial proceedings on file for US 11,402,406 B2 — the USPTO Open Data Portal returns no IPR, PGR, or CBM naming this patent, and independent web/docket searches surfaced no petition, institution decision, FWD, or CAFC appeal touching it. The bottom-line defensive posture this gives a defendant is unusual but straightforward: the patent is entirely untested at the PTAB. No claim has been canceled, no claim has been adjudicated, and there is no § 315(e)(2) estoppel wall standing between you and a well-built IPR. The corollary is the important one — the absence of PTAB activity here is not evidence of strength. This is a narrow, two-claim Toyota portfolio patent (a test-method patent, not a product patent), it issues from a family with sibling "evaluation jig" patents, and its claims have never been stress-tested against prior art in a contested forum.

Proceedings

None. No AIA trial proceeding — IPR, PGR, or CBM — has been instituted, denied, terminated, or appealed for US 11,402,406 B2.

Because there is no proceeding to analyze claim-by-claim, the mandated per-proceeding template is inapposite. What follows is instead the closest available substitute: the contested-forum record of this patent family, so defense counsel knows exactly how little has been litigated.

No proceeding — Patent Owner: Toyota Jidosha Kabushiki Kaisha

• Type: N/A — no petition filed
• Filed: N/A
• Status: N/A (structured ODP data: no AIA trial proceedings on file)
• Judge panel: N/A
• Petition grounds: N/A
• Institution decision: N/A
• Final Written Decision: N/A — no claim of this patent has ever been construed, invalidated, or sustained by the Board.
• Settlement / termination: N/A
• Appeal: No Federal Circuit appeal identified. The only "appeal-like" activity in the file is the post-allowance prosecution of the sibling continuation, US 17/854,919 (Pub. US 2022/0334143 A1), which was filed 2022-06-30 as a continuation of this application and has since gone abandoned — a prosecution event, not an appeal.
• Defensive value: Every ground available under §§ 102/103 on patents and printed publications is open to you. There is no estoppel, no prior-institution precedent from this patent's own record, and no Board construction to argue around. You would be the test case.

Family context — the sibling patents (not proceedings against this patent)

The surrounding family is worth flagging because it affects real-party-in-interest and estoppel planning, not because any of it is an AIA trial:

A defense that targets one member of this family will predictably draw parallel filings against the siblings; budget accordingly.

Search false-positive to ignore. Web results for "App[le] IPR2023-00148" show an exhibit styled "Prosecution History of US Patent No. 11,246,024." That is US 11,246,024, an unrelated patent (the '024 / '404 Mullen family), not US 11,402,406. The digits are transposed. Do not let anyone put IPR2023-00148 in a chart as a proceeding against this patent — it isn't one.

Strategic summary

Which claims are canceled vs. sustained vs. untested. All of them are UNTESTED. US 11,402,406 has exactly two claims. Claim 1 is the independent method claim — an evaluation method using a reference jig, requiring (i) connecting reference terminals to male terminals, (ii) adjusting the connection state so that a resistance including the contact-portion resistance is 0.06 mΩ ≤ R ≤ 0.15 mΩ, and (iii) evaluating performance against a 90 °C threshold at 400 A for 30 minutes, with the reference terminal structurally defined by a plurality of axial pieces plus a convex portion and adjusted with a metal band. Claim 2 depends from claim 1 and narrows the window to 0.08 mΩ ≤ R ≤ 0.1 mΩ. Neither claim has been through an AIA trial. If a demand letter cites this patent, the claims are fully live and fully valid-on-paper — but their validity has never been litigated, so no one, including Toyota, can point to a Board or court decision that backs them.

Estoppel landscape. The § 315(e)(2) ledger is empty. No petitioner has ever been estopped as to this patent, because no petitioner has ever filed. For a defendant being asserted against today, that means every prior-art ground remains available: you can raise any § 102 or § 103 ground on patents and printed publications, including art that Toyota's original examiner never saw. Two caveats matter more than the estoppel point. First, § 315(b) still binds you — if you have been served with a complaint alleging infringement, your IPR petition is due within one year of that service. Second, because there is no prior Board record, § 325(d) discretion to deny institution based on art already considered during prosecution is a live risk; pick art that is not in the original prosecution file (the file history here is short — the application was docketed 2021-08-21, received a single non-final action 2021-12-06, was responded to 2022-03-05, and issued a Notice of Allowance 2022-03-29, meaning these claims were allowed essentially on the first pass and are correspondingly less battle-hardened).

Pattern signals. There is no repeat petitioner to identify — zero filings. Toyota itself is an aggressive petitioner at the PTAB (e.g., its ongoing campaign against Emerging Automotive as patent owner, IPR2024-00786), but as patent owner on this family it has not had to litigate these claims in a contested forum at all. No defensive aggregator — no Unified Patents, RPX, or similar entity — appears anywhere in the chain for this patent. The only adversarial pressure on this family of which this record shows any trace is the ordinary foreign prosecution and the abandoned US continuation.

Recommended next steps

• Say it plainly: there is no PTAB activity on US 11,402,406. Nothing to distinguish, nothing to cite, no FWD to link. Do not let an opponent's analytics deck imply otherwise — a blank PTAB tab on a 2022-granted patent is the reality here.
• Treat the untested claims as the opening, not the conclusion. With two claims, a 400 A / 30-minute / 90 °C test protocol, and numerically bounded resistance ranges (0.06–0.15 mΩ; 0.08–0.1 mΩ), there are strong § 112 written-description and § 103 obviousness angles worth developing — particularly whether the claimed ranges are critical and whether the "resistance including a resistance at a contact portion" limitation is measurable with reasonable certainty. None of that has been tested.
• Watch the § 315(b) clock. If you are served with a complaint asserting this patent, your one-year petition window starts then. Draft the IPR on a parallel track.
• Map the family before you file. A petition against the '406 patent alone invites continuation-style siblings (the '255 jig publication, the '286 patent, the '104 "Reference jig" patent, all sharing the 2020-01-10 priority) to be asserted in reply. Consider whether the strongest single § 103 ground can be aimed at the family's common specification rather than at one claim set.
• No litigation link is available to cite. I identified no district court action and no CAFC docket for this patent. If you have reason to believe one exists, it is not in the public record this analysis could reach, and I would rather flag that gap than invent a docket number.

Confidence and limits. I have high confidence that no AIA trial proceeding exists on US 11,402,406 B2: the structured USPTO ODP block states so, and my web searches produced no contradicting petition, institution decision, FWD, or appeal. I have not independently confirmed the absence of unindexed or very recent filings via a logged-in PTAB E2E / Patent Center query, and ODP ingest lag is real (the source block itself notes the possibility of proceedings the ODP hasn't indexed). If a filing landed in the last few weeks, this report would not capture it — re-run the PTAB E2E search for application 17/116,838 before relying on the zero-count in a filing.

I'll research the assignment record for US 11,402,406 before writing.

Inventors

Pattern note: No unusual inventor-side activity. All three inventors conveyed their rights to Toyota by the standard pre-filing assignment (signature dates 2020-10-05 through 2020-10-12, i.e., ~3 months before the Jan 10, 2020 JP priority — note the signatures post-date the JP priority but precede the Dec 9, 2020 US filing). There is no evidence any inventor departed Toyota within 12 months of filing. Kawahara's inventor record shows continued Toyota filings through Dec 2024, which is inconsistent with a portfolio fire-sale narrative. No inventor-as-assignee, no inventor-reservation, no third-party co-inventor from another entity.

Original assignee

Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation) — 1, Toyota-cho, Toyota-shi, Aichi-ken 471-8571, Japan.

• Named on issued patent: Yes. Toyota Jidosha Kabushiki Kaisha is the sole assignee/applicant of record.
• Ships a product embodying the claims? Yes — importantly, the patent is about evaluation methodology, not a product. The claimed subject matter is a method for evaluating a charging connector in coolability using a reference jig with reference (female) terminals and a metal band. Toyota (and its charging-ecosystem suppliers) physically realize the apparatus side of this disclosure: the vehicle-side charging inlet / female connector, and the ChaoJi-based liquid-cooled charging hardware referenced in the specification. So Toyota is an operating company in the relevant technology space.
• Primary line of business: Automotive manufacturing (global OEM; #12 US assignee by volume per PatentsView-derived data, ~21,526 US grants 2015–2025).
• Current status: Operating, solvent, publicly traded. No bankruptcy, no acquisition, no dissolution. Corroborated by the legal-events record: Toyota paid the 4th-year maintenance fee on 2026-01-21 as a large entity (Google Patents legal events), which is dispositive that the patent is still held and maintained by Toyota.

Assignment timeline

Only one assignment is recorded for this patent. Per the USPTO Assignment Center / Google Patents legal-events record, the chain is a single inventor-to-corporate assignment; there are no post-issuance transfers, no security interests, no mergers, and no changes of name.

• 2020-10-05 to 2020-10-12 (executed; individual signature dates) / recorded 2020-12-09 — Reel 054598 / Frame 0236
  • Conveyance: Assignment (Assignment of Assignors' Interest)
  • Assignor: Kawahara, Hisato; Yuasa, Hiroaki; Kusumi, Hidetoshi (three joint inventors)
  • Assignee: TOYOTA JIDOSHA KABUSHIKI KAISHA, Japan
  • Correspondent: Not surfaced in the indexed record available to me. (USPTO free-format text is "ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:KAWAHARA, HISATO;YUASA, HIROAKI;KUSUMI, HIDETOSHI;SIGNING DATES FROM 20201005 TO 20201012;REEL/FRAME:054598/0236".) I will not fabricate a correspondent name; this field requires a direct look at the recorded cover sheet at Assignment Center.
  • Context: Standard pre-issuance acquisition of inventor rights by the corporate employer — the routine "employees assign to their employer" link. Not a fire-sale, securitization, or transfer-to-asserter.

No further Assignment Center records exist for US 11,402,406. This is itself the finding: Toyota still owns the patent outright. The two later US family members that appear in the record — a continuation (US 17/854,919 / US 2022/0334143 A1, filed 2022-06-30, abandoned) and the sibling patents US 11,695,286 B2 ("Evaluation jig") and US 12,184,104 B2 ("Reference jig") — are separate applications/patents, not assignments of this patent, and they remain within the same Toyota family. "Cited By" hits (e.g., US 2021/0218255 A1, US 11,695,286 B2, US 12,184,104 B2) are Toyota's own family citations, not adverse transfers.

Timeline diagram

timeline
    title Ownership of US 11402406
    2020 : Inventors execute assignment
         : Recorded Reel 054598 Frame 0236
         : Assigned to Toyota Jidosha KK
    2022 : Patent US 11402406 B2 issues
    2026 : Toyota pays 4th maintenance fee

NPE / troll-pattern signals

Verdict

Insufficient data (only the original assignment).

The complete assignment history of US 11,402,406 consists of a single recorded conveyance — Reel 054598/0236, executed 2020-10-05 to 2020-10-12 and recorded 2020-12-09 — in which inventors Kawahara, Yuasa, and Kusumi assigned their rights to Toyota Jidosha Kabushiki Kaisha. There is no second link, no LLC, no security interest, and no change of name against which any NPE pattern could be scored, so under the rubric the correct pick is the "only the original assignment" category. Substantively, every troll signal is not present: the assignee is a solvent, product-shipping OEM that continued to hold and pay maintenance fees on the patent (large-entity 4th-year fee, 2026-01-21), and the prior-art review found no litigation naming this patent.

Verification link (Assignment Center): https://assignmentcenter.uspto.gov/ — enter Patent Number 11402406 (or Reel/Frame 054598/0236). Mirrored index: https://assignment.uspto.gov/patent/index.html.

Caveat: the recorded correspondent (the attorney/firm on the assignment cover sheet) is the one field I could not confirm from indexed sources and should not be inferred. If you need it for the repeat-correspondent signal, pull the Reel 054598/0236 cover sheet directly from Assignment Center — though with only one link in the chain, it would not change the verdict.

I'll research the cited prior art for US 11,402,406. Let me search for the specific references.

Good progress. Let me research the remaining cited references.

Prior-Art Analysis — US 11,402,406 B2 ("Evaluation method")

Scope note / caveat first. I was able to pull the patent's own front-page citation lists and verify several references against open web sources, but I ran out of search budget before I could individually re-verify every cited reference's full text. The reference lists themselves are taken verbatim from the authoritative full text at https://patents.google.com/patent/US11402406/en (fetched 2026-09-24). Where I could not independently open a reference's full text this session, I flag it and rely on the title/assignee/date of record plus general knowledge — those are marked [unverified full text]. I do not have authenticated USPTO PatentCenter / PATENTSCOPE query access from this session, so this is an analysis of the patent's own citation lists, not a fresh examiner-style search.

Strict-ID compliance. The patent under analysis is literally US 11,402,406 B2. I did not substitute or auto-correct any number. Note two adjacent-looking but different identifiers that should not be conflated: the abandoned continuation US 2022/0334143 A1 (application 17/854,919) and the sibling US 2021/0218255 A1 / US 11,695,286 B2 ("Evaluation jig"). These are Toyota's own family members, not prior art.

1. Legal framework applied

• The application was filed 2020-12-09 with priority to JP 2020-003138 (2020-01-10) → AIA §102 applies.
• References published before 2020-01-10 are prior art under §102(a)(1).
• U.S. patents/applications effectively filed before 2020-01-10 but published after it are prior art under §102(a)(2).
• Anticipation under §102 requires a single reference disclosing every element of the claim, arranged as claimed. For method claim 1, that means one reference must disclose the full combination: (i) a jig/"reference jig" with paired reference terminals on paired male terminals of a connector; (ii) adjusting connection state to a resistance-including-contact-resistance of 0.06–0.15 mΩ; (iii) a pass/fail criterion of ≤90 °C at 400 A for 30 min; (iv) reference terminals having plural axially-extending pieces spaced about a center axis with an inward convex portion; and (v) tightening those pieces with a metal band.

Bottom line up front: No cited reference — on the face of the patent or in its family citation lists — discloses this full combination. The cited art is best characterized as background / analogous art that individually touches isolated elements. There is therefore no §102 anticipation shown by any cited reference; the realistic §103 exposure lies in combining, e.g., a female-terminal structural reference with a cooling/liquid-cooled-connector reference.

2. References cited on the face of US 11,402,406

(a) "Patent Citations (11)" — the substantive citations

3. "Family Cites Families (12)" — prior art cited in the JP/EP/CN siblings

These were cited during prosecution of the family members (JP 6958643 B2, EP 3848231 B1, CN 113112112 B), not necessarily against the U.S. case; treat them as secondary. Details from the family-citation list; full texts [unverified].

4. What each claim actually needs, and which references map where

Claim 1 elements and the best (but still insufficient) disclosures:

Claim 2 (resistance narrowed to 0.08–0.1 mΩ) is narrower still and is anticipated by nothing cited.

5. Conclusion

1. US 11,402,406 B2 is correctly identified and its citation lists were read literally; no similar-number substitution was made.
2. No cited reference anticipates claim 1 or claim 2 under 35 U.S.C. §102. Every reference maps to at most one or two isolated elements of the claim; none discloses the claimed combination of (i) a jig-based evaluation method, (ii) the 0.06–0.15 mΩ resistance-adjustment step, (iii) the ≤90 °C at 400 A/30 min criterion, (iv) the plural-axially-extending-piece-with-convex-portion reference terminal, and (v) the metal-band tightening step.
3. Most technically relevant references (for any §103 challenge or freedom-to-operate context):
   • Tesla US 2020/0282851 A1 and TE US 2020/0353830 A1 — liquid-cooled EV charging connector with paired power contacts, high-current/heating context (both are §102(a)(2)-type art given their post-priority-2020 publication dates).
   • Kittell US 9,457,681 B2 — the only cited reference touching a 400 A current level coupled with temperature constraints and resistance (though in a battery module).
   • WO 2019/171914 A1 and US 7,658,641 B1 — the two references most relevant to the claimed terminal structure and band-tightening (the collet reference is the single best structural analogue).
   • JP 2019-187035 A / US 2019/0308519 A1 — the liquid-cooled charging connector expressly named in the patent's own Background.
4. Confidence / limitations: The bibliographic dates, assignees, and titles above are drawn from the patent's authoritative citation lists and are reliable. My characterizations of the substantive content of items marked [unverified full text] rest on title/assignee/date plus general domain knowledge rather than a freshly opened specification this session. For a formal invalidity opinion, each reference's full text should be pulled from USPTO PatentCenter/PATENTSCOPE and charted element-by-element.

I'll ground the key prior-art references from the patent's citation list before building the §103 analysis.

Obviousness Analysis — US 11,402,406 B2 under 35 U.S.C. § 103

Scope/grounding note. Per the task, I am analyzing obviousness over the references appearing in the "Prior Art"/Citations section of the patent's Google Patents page (https://patents.google.com/patent/US11402406/en), plus the background reference JP 2019-187035 identified in the specification itself. I retrieved abstracts/portions of several key references (cited with URLs below); I did not parse the full text of every listed reference, so where my characterization rests on a title only, I flag it. All references predate the 2020-01-10 priority date and therefore qualify as AIA § 102(a)(1) or (a)(2) art (e.g., Tesla US 2020/0282851 A1 has a 2019-03-06 effective filing date and thus qualifies under § 102(a)(2) despite publishing 2020-09-10).

A. Analytical framework

The claim is a method of testing/evaluation. Under Graham v. John Deere, I assess (1) scope and content of the prior art, (2) differences between the prior art and the claims, (3) level of ordinary skill, and (4) secondary considerations. Under KSR Int'l v. Teleflex, the central question is whether the claimed subject matter is "more than a predictable variation" over the prior art; a combination is obvious where there is an apparent reason to combine (e.g., known technique to improve a similar device, a design incentive, a finite number of identified predictable solutions, or a "try it" situation). For numerical ranges and method steps of this type, In re Aller, In re Woodruff, and In re Peterson supply the range-specific rules, and MPEP 2144.04 governs "optimizing a result-effective variable."

Level of ordinary skill: a person of ordinary skill here would be an electrical/mechanical engineer or connector-test engineer with a few years' experience in EV high-power connector design and/or the design of high-current electrical connectors, familiar with DC fast-charging standards (e.g., ChaoJi, CCS) and with contact-resistance/thermal testing.

Key claim-construction observation (from the earlier section, relied on here): the granted claim uses "reference jig / reference terminals," "performance required for a connector" (not "coolability"), and "a resistance including a resistance at a contact portion" (not "contact resistance"). That last broadening is important to the § 103 analysis: the claim does not require a pure contact-resistance value — only some overall measured resistance that includes the contact-interface resistance. This makes the range easier to meet and easier to map onto prior-art test setups that measure total loop resistance across a mated pair.

B. Element-by-element mapping of claim 1 to the cited art

The mapping shows that every structural and functional element of claim 1 appears, individually, in a cited reference; the only question is whether the combination and the numerical window would have been obvious.

C. Combination 1 (primary): liquid-cooled EV charging connector + split-finger female terminal + adjustable band clamp + temperature-based pass/fail test

References combined:

• Primary A (the article under test): JP 2019-187035 A / US 2020/0282851 A1 (Tesla) — a liquid-cooled EV charging connector with a pair of power contacts, expressly concerned with contact heating at high charging current and with measuring/characterizing connector contact temperature rise (Tesla discusses current "100 Amps or more" up to "2000 Amps or more" and states charging connectors may exhibit a "50 degree C. rise … while the connector … has a 5 degree C. external rise"). URL: https://patents.google.com/patent/US20200282851A1/en.
• Primary B (jig terminal structure): WO 2019/171914 A1 — female terminal with an axially split insertion tube (plural pieces extending along the axis) and a separate biasing means that holds the tube in a reduced-diameter state to obtain "large contact pressure" while "suppressing fluctuations" in contact pressure/insertion force. URL: https://patents.google.com/patent/WO2019171914A1/en.
• Primary C (adjustable tightening): US 7,658,641 B1 — split barrel clamp (slots → compressible arms) tightened by a band clamp with an adjustable worm-drive screw / compression nut to make a "uniform electrical connection." URL: https://patents.google.com/patent/US7658641B1/en.
• Primary D (performance criterion): US 2019/0319317 A1 (Panasonic) — detects/infers connector contact degradation from temperature at the contact of the connector and from resistance/voltage behavior, and explains that increased contact resistance → connector heating. URL: https://patents.google.com/patent/US20190319317A1/en.
• Optional supplemental: US 4,207,611 A (calibrated test method/fixture for a vehicle electrical system) for the "calibrated evaluation jig/method" framing.

Motivation to combine (KSR rationales):

1. Design incentive / problem to be solved. Both Tesla and JP 2019-187035 exist because high-current fast charging makes contact heating the limiting factor; a connector vendor/specifier must therefore be able to verify cooling adequacy. Tesla itself quantifies connector contact temperature rise, which is exactly the "performance" being measured. This supplies the reason to build the evaluation method.
2. Known technique to improve a similar device. WO 2019/171914 and US 7,658,641 are both in the same field (high-current electrical connection) and address the same sub-problem the claim addresses — controlling contact pressure to suppress fluctuation in contact resistance. WO 2019/171914 expressly frames its goal as suppressing fluctuation of contact pressure/contact resistance; that is the very reason the patent's own specification gives for fixing the resistance window ("If the contact resistance … varies whenever the evaluation is made, the evaluation provides an unreliable result"). A POSITA would therefore be motivated to use an adjustable band to hold contact resistance in a narrow band before running the thermal test.
3. Predictable, finite solution space. Using an adjustable band/screw to set clamping force (US 7,658,641) — and thus to dial in a measured resistance (Panasonic measurement) — is a routine, mechanistic step with a predictable result. Setting it to a numeric window is optimization of a result-effective variable.
4. Reasonable expectation of success. Nothing about combining a spring-finger socket (B) with a clamp (C) and a temperature criterion (D) is unpredictable; the combination simply standardizes a test variable.

Result: Claim 1 would have been obvious over A+B+C+D; claim 2 (0.08–0.1 mΩ) is a routine narrowing of the working range.

D. Combination 2: high-current rapid-charge context + contact-resistance/thermal connector diagnostics + collet/split-barrel socket

References combined:

• US 9,457,681 B2 (Kittell, "Method for high-current rapid charging") — establishes the 400 A-class, rapid-charge regime and the need to manage connector heating.
• US 2019/0319317 A1 (Panasonic) — the criterion: monitor connector-connection temperature (and resistance/voltage drop) to judge whether the connection is acceptable, i.e., temperature as the pass/fail metric for connector contact quality.
• US 7,658,641 B1 (Mechanical Answers) — a split barrel/collet with plural compressible arms and an adjustable band clamp, which supplies both the "plural axially-oriented pieces + convex contact + metal band tightening" structure and the adjustability to set contact pressure.
• US 4,207,611 A (Ford) — "calibrated testing of a vehicle electrical system," supplying the notion of a calibrated, repeatable fixture-based test of an electrical system under load.

Motivation: Kittell supplies the loading profile (high-current rapid charging), Panasonic supplies the observable (connector temperature as a proxy for contact quality), Ford supplies the calibration/testing-method template, and Mechanical Answers supplies the adjustable tightenable socket. Combining a calibration mindset (Ford) with a known test variable (contact resistance → temperature, Panasonic) to define an adjustable, repeatable connector test is precisely the predictable combination KSR addresses. Here the "design incentive" rationale (Combination 1, rationale 1) and "known technique improving a similar device" rationale (rationale 2) both apply.

E. Combination 3: liquid-cooled connector art (Mark / TE) + split-finger terminal art (AutoNetworks) + band clamp

References combined:

• US 2016/0270257 A1 (Gregory Thomas Mark, "Actively cooled electrical connection") and US 2020/0353830 A1 (TE Connectivity Germany, "Electrical Plug Connector And Electric Plug-In Connection") — actively cooled plug connections with mating pin/socket contact constructions.
• US 9,496,636 B2 / WO 2019/171914 A1 (AutoNetworks) — female terminals with plural inward-projecting contact portions (convex portions) on resilient pieces, expressly to deliver a "proper contact pressure."
• US 7,658,641 B1 — the band clamp/adjustable tightening to set and hold the pressure.

Motivation: Cooling performance of a plug connection is directly governed by the thermal resistance at the pin/socket interface, which is a function of contact pressure and contact resistance — this is common engineering knowledge and is the express premise of both TE's and Mark's cooling-at-the-contact teachings. A POSITA seeking to evaluate cooling (the stated task of the patent) would naturally pair (i) a cooled plug connector, (ii) a socket whose contact pressure is engineered and held constant (AutoNetworks), and (iii) an adjustable clamp (Mechanical Answers) to pin the pressure/resistance so the cooling measurement is meaningful. This is a classic "combine known elements according to known methods to yield predictable results" case (KSR).

F. The numerical limitations — 0.06–0.15 mΩ, 0.08–0.1 mΩ, 90 °C, 400 A/30 min

1. The resistance range is an obvious optimization or an obvious "result-effective variable" range. The variable (contact/clamping resistance) is result-effective — the prior art itself (WO 2019/171914; Panasonic US 2019/0319317) ties contact quality/resistance to connector heating. Where the prior art teaches that the variable matters, selecting a sub-range to stabilize a test is routine optimization. In re Aller (range optimization), In re Woodruff / In re Peterson (overlapping/adjacent ranges), MPEP 2144.04.
2. The 400 A / 30 min / 90 °C evaluation parameters are dictated by the application and the applicable standard, not invented here. The specification itself states the connector is "based on the ChaoJi standard" and that 400 A rapid charging is the design case. Where a test parameter is fixed by the environment of use and a governing industry standard, selecting it is not inventive. Tesla and Kittell supply high-current (≥100 A, up to thousands of A) context; the specific 400 A and 30-min figures reflect real-world DC-fast-charge duty.
3. The claim's broadening to "a resistance including a resistance at a contact portion" makes the window even easier to meet: any test setup measuring total mated-pair resistance (e.g., a milliohm meter or voltage drop, as Panasonic and the patent both contemplate) can be adjusted into this range by tightening the band. The patent itself acknowledges measurement can be by "a milliohm tester or … a voltage drop caused when a current of 400 A is supplied."
4. Claim 2 (0.08–0.1 mΩ) is a still-narrower optimization of the same result-effective variable with no asserted criticality beyond the same stated benefit (≤90 °C), so it is a fortiori obvious if claim 1 is.

G. Secondary considerations and anticipated rebuttals

(a) "Criticality" of the claimed range / unexpected results. The strongest would-be rebuttal is that the 0.06–0.15 mΩ window is a critical range producing an unexpected result (≤90 °C at 400 A). But the specification's own reasoning is mechanistic and expected, not surprising: higher contact resistance → more Joule heating → higher temperature. That is the expected relationship, so it tends to support obviousness rather than rebut it. To rebut, the applicant would need comparative data showing the claimed range behaves differently in kind (e.g., a sharp threshold) versus adjacent ranges, and would need to show that this was unexpected against the art. The disclosure as presented reads as routine windowing, not criticality. (I flag this as a judgment call; the intrinsic record I have does not contain a comparative data showing a critical point.)

(b) Teaching away. I saw no teaching away. WO 2019/171914 and Mechanical Answers both teach toward controlling/adjusting contact pressure; Panasonic teaches toward using temperature of the connection as an indicator. None discourages the claimed combination.

(c) Non-analogous art as to US 4,414,076 A. US 4,414,076 A ("Low resistance ohmic contact," Navy) is microelectronics/semiconductor art (ohmic contacts on p-type InP, https://patents.google.com/patent/US4414076A/en) — it is not analogous to connector testing under the In re Bigio field-of-endeavor / KSR "reasonably pertinent" test. It should not be relied on as a primary reference; its citation on the face of the patent appears to be for the generic notion of a "low-resistance contact." A challenger relying on it should drop it. It adds nothing the other references don't supply.

(d) The "removing step" is not in the claims. As noted in the earlier summary, the granted claim does not recite the specification's partial removal of the male casing's tubular wall to open an "operating space" for the adjustment tool. A challenger therefore does not need art for that step. (This also means the claim is broader than the commercial embodiment and correspondingly easier to invalidate over art that provides any accessible route to adjust the band.)

(e) § 101/§ 112 side notes (not § 103, flagged for completeness). An evaluation method claim of this type invites subject-matter eligibility scrutiny (a mental/organizational process or a test protocol), and the claim's "performance required for a connector" is quite functional. These are separate invalidity theories and are outside the § 103 scope of this task; I note them only because they are typical companion challenges.

H. Bottom line

• Claim 1 is likely obvious under § 103 over, at minimum, the combination of (i) a liquid-cooled EV charging connector that heats at its contacts at high current (JP 2019-187035 / Tesla US 2020/0282851 A1 / Mark US 2016/0270257 A1 / TE US 2020/0353830 A1); (ii) a female "reference" terminal having plural axially extending pieces with inward convex contact portions (WO 2019/171914 A1 and/or US 9,496,636 B2); (iii) an adjustable metal band/clamp that tightens those pieces to set contact pressure (US 7,658,641 B1); and (iv) a connector-performance criterion based on connection temperature (Panasonic US 2019/0319317 A1), with the numeric window supplied by routine optimization of a result-effective variable.
• Claim 2 is obvious as a plain narrowing (0.08–0.1 mΩ) of the same result-effective variable.
• Strongest challenger theory: Combination 1 (liquid-cooled connector + AutoNetworks split-finger socket + Mechanical Answers band clamp + Panasonic temperature criterion), with Ford US 4,207,611 A as a "calibrated test method" teaching.
• Best non-obviousness arguments for the patentee: (1) asserted criticality/unexpected results of the 0.06–0.15 mΩ window; (2) that no single reference teaches adjusting the connection state to a specified resistance value before running the thermal test (i.e., the sequence/closed-loop adjustment as a whole). Argument (2) is the more plausible, because the claim recites the adjusting step as a distinct, quantified gate before the evaluating step — but it is weakened by WO 2019/171914's express teaching of a biasing means to hold contact pressure/contact resistance steady, and by the claim's broadening of "contact resistance" to "a resistance including" it.

Confidence caveats: (i) I reviewed abstracts/portions, not full texts, of several references; specific column/paragraph cites should be verified before any formal invalidity contentions. (ii) My "criticality" assessment is a judgment based on the intrinsic record provided and could change with comparative test data. (iii) No litigation/PTAB record for US 11,402,406 was found (per the earlier section), so this is a validity-risk assessment, not a challenge actually raised.