US 11402442

I'll search for the specific patent number and any related litigation, then summarize.

Search scope and a caveat up front

I ran targeted queries for the literal string 11402442 together with terms for litigation, PTAB, and Federal Circuit activity. My tools here are general web search (surfacing Google Patents, Justia Patents, courtlistener, and CAFC opinion PDFs), not a live PACER/docket or USPTO PatentCenter API. So the litigation finding below is a "nothing surfaced" result, not a certified negative docket check. Also note the number is US 11,402,442 B2 (the grant); US 2021/0311142 A1 is the same application's pre-grant publication.

Bibliographic data (from the granted patent text)

Abstract (verbatim)

"An apparatus for validating magnets on site, including a standard reference magnet for providing a governing reference, a reference magnet for providing a reference based on the governing reference, a gauss meter, a hall probe, and a scanner. The reference magnet is arranged to be taken on site for further magnetic validation and includes guide members to target a nominated magnetic field density."

Independent claims — plain-language overview

The patent has 8 claims total, only 2 independent (claim 1 and claim 6); claims 2–5 depend from claim 1, claims 7–8 from claim 6.

Claim 1 — Apparatus (virtual, off-site magnet validation kit).
A kit of cooperating parts: (a) a standard reference magnet that serves as the governing/national-traceable reference; (b) a second reference magnet whose reference value is derived from that governing reference and which is built to be carried to a customer site; (c) a gauss meter; (d) a Hall probe; and (e) a scanner. The point of novelty is the field-reference magnet having guide members (brass sleeves, per claim 3) that physically index the Hall probe so it lands on a nominated magnetic field density — i.e., the measurement geometry is fixed and repeatable rather than left to operator judgment.

Claim 6 — Method (on-site validation workflow).
Steps: calibrate a reference magnet to establish the reference; take or send that magnet on site; align the Hall probe to a desired position; capture a scan (image — claim 5 specifies a camera for the apparatus) of both the probe's position and the field-density reading; transmit that scan externally for validation; and only once externally validated, use the Hall probe to validate the site magnets. The gated "validate the validation" step — remote mentor/reporting lab confirms the field reading on the reference magnet before the operator is trusted to measure production magnets — is the practical core.

Notable difference from the published application: granted claim 6 reads "taking or sending the reference magnet on site," whereas US 2021/0311142 A1 recited only "taking the reference magnet on site."

Supporting dependent matter: claim 2 (magnetically shielded case), claim 3 (brass sleeves as the guide members), claim 4 (scanner captures probe position + field density), claim 5 (scanner = camera), claim 7 (guide members used to align the probe), claim 8 (gaussmeter displays the field-density reading).

Litigation / CAFC 2026 docket search — nothing found

• No CAFC docket, opinion, or order referencing 11,402,442 surfaced in 2026 (or any year) results.
• No PTAB petition (IPR/PGR) referencing it surfaced.
• No district court complaint or docket entry referencing it surfaced.
• The "hits" containing the digit string 11402442 were unrelated (e.g., a Missouri unclaimed-property PDF listing it as an apparent account number; references to different patents such as US 11,446,424 and US 9,333,946).

Interpretation: on the record available to me, US 11,402,442 B2 appears to be unlitigated as of this search. Given the tooling limits above, treat that as "no evidence of litigation," not as proof of no litigation.

Uncertainty flags

• I have no authoritative independent confirmation of the current assignee beyond the recorded assignment in the patent text Google Patents reproduces; ultimate ownership could differ.
• The AU counterpart (AU 2021202022 A1) is shown as "not_active / Abandoned" on the source page — I did not verify its prosecution history independently.
• I cannot confirm whether the "Virtual Magnet Validation Information Document" referenced in the specification has any separate copyright/trademark or trade-secret protection, and nothing in the patent claims it.
• No claim-construction order, IPR institution decision, or reexamination certificate for this patent surfaced, so the claim-scope observations above are based solely on the granted claim language.

I'll research litigation involving US patent 11,402,442 across patent litigation databases.

Initial searches didn't surface any litigation. Let me search more targeted litigation databases specific to this patent number.

Let me try a few more targeted searches on specific litigation databases and the patent owner.

Litigation Search Results — US Patent No. 11,402,442

Summary finding: No litigation is known involving US Patent No. 11,402,442.

I searched patent-litigation resources (Unified Patents litigation database, CourtListener/RECAP, Docket Alarm, PTAB/PTActs, and general CAFC/PACER-indexed results) for the specific number 11,402,442 ("Magnetic validation," William John Baker; current assignees KR Baker Nominees Pty Ltd and RJ Baker Holdings Pty Ltd). I did not identify any district court complaint, CAFC appeal, ITC action, or PTAB proceeding (IPR/PGR/CBM) asserting or challenging this patent.

What the searches returned

• No case hits for the exact number. Querying the exact identifiers ("11402442", "11,402,442", and the patent's title/technology) returned no matching district court or appellate dockets. Results containing similar-looking but different numbers (e.g., patents/numbers such as 11402442 appearing in unrelated bates/invoice lists, case numbers like 1:19-cv-00742, and unrelated patents) were excluded as not matching this patent.
• No assignment/litigation-based signals. The only public events attached to this patent are prosecution and ownership events visible on its face (grant 2022‑08‑02; assignment to RJ Baker Holdings / KR Baker Nominees recorded 2024‑12‑23), not enforcement activity.
• The patent's own family evidence is consistent with no litigation. The Google Patents record lists only one family application (US 17/223,108) plus the Australian counterpart (AU2021202022A1, noted as not_active / abandoned), and lists no citing litigation — only a single third-party citation (CN115219960A). No "Related US Applications" or litigation tab entries appear.

Case table

Important caveats and limits on this conclusion

1. Absence of evidence is not definitive proof. My searches relied on publicly indexed sources. Very recent filings (e.g., within the last few weeks) may not yet be indexed, and some district court dockets are not freely searchable except through PACER, to which I do not have direct access here. A definitive negative should be confirmed via a PACER docket search by patent number, a Docket Navigator / Lex Machina patent-by-patent report, and a current Unified Patents litigation-page check for this specific patent.
2. Later-acquired owners can begin enforcement. The 2024 assignment to KR Baker Nominees Pty Ltd and RJ Baker Holdings Pty Ltd (effective 2024‑12‑09) means future litigation could arise even though none is presently known.
3. No auto-correction applied. I treated the identifier strictly as 11,402,442 and did not substitute near-matching numbers that surfaced in unrelated contexts.

Bottom line: Based on the available public sources, there is no known litigation — no filed suits, no appeals, and no PTAB challenges — involving US Patent No. 11,402,442 as of this search. If you need a court-certified negative, I recommend a paid docket query (Docket Navigator or Lex Machina) plus a direct PACER search on the patent number.

Proceedings overview

Total AIA trial proceedings on US 11,402,442 B2: zero (0). Breakdown by status: 0 active, 0 with claims invalidated, 0 with claims sustained, 0 settled, 0 with institution denied — because no petition for Inter Partes Review, Post-Grant Review, or Covered Business Method review has ever been filed against this patent. The structured "PTAB proceedings on file" block (USPTO Open Data Portal) is the canonical source here and returns an empty set; my web searches independently corroborate it. The bottom-line defensive posture is therefore "untested, not hardened": every claim — including the two independents, claim 1 (apparatus) and claim 6 (method) — remains presumptively valid and has never been construed by the Board or canceled. A defendant cannot point to a single PTAB paper as invalidating art or as Fintiv/§ 325(d) leverage, but equally, a defendant who files first gets the whole PTAB runway to themselves.

⚠️ Search caveat (consistent with the earlier sections): my tools are general web search and the ODP summary supplied in this prompt, not a live PTAB E2E or PatentCenter docket pull. I did not find so much as a proceeding number to report, and I will not invent one. Treat this as a well-corroborated negative, not a certified one.

No proceedings to itemize

There is no IPR20xx-XXXXX or PGR20xx-XXXXX number to report, no petitioner, no panel, no institution decision, no Final Written Decision, no settlement, and no Federal Circuit appeal. Anything I wrote in the per-proceeding template below would be fabricated, so I am leaving it empty by design:

• Type: n/a
• Filed: n/a
• Status: n/a
• Judge panel: n/a
• Petition grounds: n/a
• Institution decision: n/a
• Final Written Decision: n/a
• Settlement / termination: n/a
• Appeal: n/a
• Defensive value: n/a

False-positive filter (important). Searching on the digit string and on "Baker" surfaces several PTAB documents that are not about this patent or this inventor: IPR2019-01585 and IPR2019-01586 concern US 8,929,442 B2 (Realtime Adaptive Streaming / ARRIS — data compression), and IPR2019-01092 concerns US 6,928,442 B2 (PersonalWeb — file distribution). Those are '442 patents of an entirely different number (8,929,442 and 6,928,442 vs. 11,402,442) and different owners. Several hits also name an expert "R. Jacob Baker, Ph.D." in memory/DRAM IPRs — that is a different Baker from the inventor here, William John Baker, and is not evidence of anything regarding this patent. Do not let any of these leak into a validity or estoppel analysis.

Strategic summary

Claim status across the PTAB docket: all eight claims are UNTESTED. Nothing has been canceled, nothing has been held patentable, nothing has been construed. Claim 1 (standard reference magnet + field reference magnet + gauss meter + Hall probe + scanner, with guide members targeting a nominated field density), claims 2–5 (shielded case; brass-sleeve guides; scanner capturing probe position and field density; camera), claim 6 (calibrate → take/send on site → align probe → scan position and reading → send externally for validation → then measure), and claims 7–8 (guide members used for alignment; gaussmeter displays the reading) are all live and all in their original granted scope. Note the one prosecution-era refinement already flagged in the earlier section: granted claim 6 recites "taking or sending the reference magnet on site," broader than the pre-grant publication's "taking." That broadening has never been tested adversarially.

Estoppel landscape: there is none, which cuts both ways. Because there is no Final Written Decision under 35 U.S.C. § 318(a), § 315(e)(2) estoppel is not triggered for anyone. A defendant today may raise any invalidity ground in district court (or the ITC) — § 102, § 103, § 112, and even § 101 subject matter — with no IPR-based carve-out. Conversely, there is no prior petitioner whose unsuccessful grounds a defendant could inherit for free, and no Board claim construction or institution-denial reasoning to borrow for a § 325(d) or discretionary-denial argument. The record is a blank slate; whoever files first writes it. One practical note: because a first IPR would be the patent's first post-issuance challenge, a petition can candidly argue the Board is the efficient first mover, which is exactly the posture petitioners have successfully used to defeat Fintiv-type denials (compare the argument in the Granite Vehicle Ventures / IPR2025-00943 reply, which leaned on the patent "never [having] been challenged in a post-issuance proceeding").

Pattern signals: none of the usual ones are present. No serial petitioner (there is no petitioner at all), no IPR-vs-IPR joinder chain, no patent owner with a history of defending through PTAB (no appeals to the Federal Circuit, so no CAFC docket and nothing on CourtListener), and no defensive aggregator (e.g., Unified Patents) in the chain. What we do see is a small-entity, two-company ownership structure — RJ Baker Holdings Pty Ltd and KR Baker Nominees Pty Ltd, recorded 2024-12-23 and effective 2024-12-09, assignor William John Baker — with the AU counterpart, AU 2021202022 A1, shown as abandoned. That profile (narrow patent, Australian priority, small entity, maintenance fee 4th year paid 2025-08-06, no IPR history) is consistent with a patent that has been licensed or worked rather than asserted broadly. Well-asserted patents eventually attract IPRs; this one hasn't.

Timing note relevant to filing strategy. Grant issued 2022-08-02, so the PGR window under § 321(c) closed 2023-02-02 and is unavailable regardless — and CBM review sunset for new petitions on 2020-09-15, before this patent even issued. IPR is the only remaining AIA trial vehicle, and it remains available indefinitely against the live claims (subject to the § 315(b) one-year bar once a defendant is served, and to § 315(a)(1) if the petitioner/privy first files a declaratory-judgment action of invalidity). Anticipated expiration is listed as 2041-04-06, so a § 112/§ 101-based district-court attack carries no PGR-style best-mode or written-description-for-free benefit here — those grounds are court-only.

Recommended next steps

• If you are a defendant and hoped to inherit an invalidated claim: there is nothing to inherit. No claim of US 11,402,442 B2 has been canceled or held unpatentable by the Board, so there is no Final Written Decision to link to on PTAB E2E and no claim-level disposition to quote. Any assertion of claim 1 or claim 6 must be met with your own invalidity case.
• If you are being asserted and want to file, the clock matters more than the art. The instant a complaint alleging infringement is served on you, your real party in interest, or your privy, the § 315(b) one-year bar starts running, and the § 315(a)(1) bar is triggered if you first file a DJ action of invalidity. Because there is no prior FWD, a first-filed IPR would set the Board's claim construction with no competing record — a genuine advantage, but also the reason to move before any parallel DJ filing.
• Milestones if you file: institution decision due within 6 months of the petition's filing-date accord (35 U.S.C. § 314(b)); upon institution, the trial must reach a Final Written Decision within 1 year of institution, extendable up to 6 months for good cause (§ 316(a)(11)). No such dates exist today for any proceeding.
• If no PTAB activity exists, say so plainly — which is where I land. The absence of any AIA trial is itself the signal: this patent has not been subjected to adversarial post-grant testing, so its claim scope is whatever the district court says it is, unconstrained by any Board precedent.

Verification sources and residual uncertainty

• Structured source of truth: the "PTAB proceedings on file" block (USPTO Open Data Portal AIA-trial data) supplied with this prompt — empty for this patent as of the most recent ingest.
• Corroborating searches run for this section: literal 11402442, 11,402,442; combinations with "PTAB," "IPR," "inter partes review," "post-grant review," "petition"; the patent title "Magnetic validation"; the owners "KR Baker Nominees" / "RJ Baker Holdings"; and inventor "William John Baker." All returned either nothing relevant or the unrelated '442-numbered patents and unrelated "Baker" experts flagged above.
• I could not independently confirm the absence of a recently filed petition that PTAB E2E has posted but ODP has not yet indexed. If that gap matters commercially, pull the patent's trial record directly in PTAB E2E and confirm against the USPTO PatentCenter "Proceedings" tab before relying on the negative.
• No proceeding number, judge panel, ground, or disposition is stated anywhere in this report because none exists to state. If you find one I missed, treat that as a contradiction to flag, not something I would have silently omitted.

I'll research the assignment/ownership chain for US 11,402,442 across the assignment databases and related sources.

Good — this surfaces the real ownership picture. Let me pull the actual assignment records and correspondent details.

Ownership-chain analysis — US 11,402,442 B2 ("Magnetic validation")

Tools caveat up front: I was cut off by a search-step limit before I could pull the actual Assignment Center cover sheet (and therefore the correspondent of record). Everything below is grounded in the Google Patents legal-events transcription of the recorded assignment (which reproduces the reel/frame), plus trademark and corporate records for the assignee entities. Where I could not retrieve a field, I say so rather than guess. Note also the prior sections' finding of no known litigation.

Inventors

Unusual-pattern check: Not applicable in the classic sense. There is a single inventor, and he is the founder-principal of the family business, not an employee-inventor who departed. There was no pre-issuance corporate assignment (he filed personally), so there is no "inventors assigned out of the company" pattern. What is mildly notable is the reverse: the founder filed individually in 2021 and only assigned into the family holding companies in December 2024, ~2.5 years post-grant — a founder-side estate/succession consolidation, not a portfolio monetization.

Original assignee

• Original assignee on the issued patent: "Individual" — i.e., William John Baker personally. No company was the applicant/assignee at filing, so there is no "original corporate assignee" whose business can be characterized. The AU provisional (AU 2020901115) likewise claims priority from the same individual.
• Underlying operating business (the practical entity): the Baker family's magnetic-separation group — Magnattack Global / WJB Engineering, Unanderra / Figtree / Russell Vale, NSW, Australia. Primary line of business: design and manufacture of magnetic separators and metal-fragment-control equipment for the food and grain processing industries (Mag-Ram self-cleaning separator, Rapidclean grate magnet, spherical pneumatic transfer magnets, RE80 magnet technology), plus HACCP-endorsed magnet validation reporting (via AMR Consulting, partnered with WJB Engineering since 2007–2008).
• Status: operating, not acquired/dissolved/bankrupt. The group is actively filing US trademarks through 2025 (e.g., CO-FORCE, ser. 98554448, filed 2024-05-16; MSA MAGNETICS, ser. 99390483, filed 2025-09-12).
• Product embodying the claims: yes, and it is directly on point — US trademark ser. 90792753 "VERI-TEST" (filed 2021-06-24, owned by KR Baker Nominees Pty Ltd / RJ Baker Holdings Pty Ltd) is described as a "Verification kit comprised of magnetic materials, namely, certified standard magnets used in calibration of Gauss meters." That is the commercial embodiment of claim 1's "standard reference magnet … reference magnet … gauss meter … hall probe." Ser. 90791185 "CALI-MAG" (same co-owners) likewise covers "magnetic apparatus … for foreign metal fragment control and food safety."

Assignment timeline

Only one post-issuance assignment is recorded on the patent's legal-events record:

• 2024-12-09 (executed) / recorded 2024-12-23 — Reel 069667/0979
  • Conveyance: Assignment (Assignment of Assignors' Interest)
  • Assignor: BAKER, William John (sole inventor)
  • Assignees: KR Baker Nominees Pty Ltd and RJ Baker Holdings Pty Ltd (both Australian Pty Ltd companies; assignee correspondence addresses on the group's US trademark filings are Unanderra NSW 2526 and Figtree NSW 2525 / Russell Vale NSW 2517, Australia)
  • Correspondent: Not retrieved — the Assignment Center cover sheet was not reachable before my search budget ran out. This field must be read directly off reel 069667/0979 at the Assignment Center. For triangulation only (not a substitute): the Australian trademark portfolios for these same entities list the correspondent as "WJ & GM BAKER & WJB NOMINEES PTY LTD," NSW 2526, AU — i.e., self-representation by a family-named address, not an outside NPE-style IP filing service. I cannot confirm the US recording correspondent is the same.
  • Context: internal / related-party reorganization within the founder's family-controlled operating group — the equity in the patent was moved from the inventor personally into two jointly owned family proprietary companies (KR Baker Nominees and RJ Baker Holdings). No consideration to a third party is evidenced; no operating-asset sale, securitization, or bankruptcy is implicated.

No other assignments are recorded — no assignment at filing, no security agreement, no merger, no release, no change of name. The chain is: Inventor (individually) → [reel 069667/0979] → KR Baker Nominees Pty Ltd + RJ Baker Holdings Pty Ltd.

Timeline diagram

timeline
    title Ownership of US 11402442
    2020 : AU provisional filed by WJ Baker
    2021 : US application filed
         : Applicant is the inventor as individual
    2022 : US patent 11402442 B2 granted
         : Title held by inventor personally
    2024 : Assigned to KR Baker Nominees
         : Assigned to RJ Baker Holdings
         : Recorded at reel 069667 0979

NPE / troll-pattern signals

1. Shell-entity transfer — NOT PRESENT. The only transfer (reel 069667/0979, exec. 2024-12-09) moved the patent to two Australian Pty Ltd companies that are co-owners of a live US trademark portfolio covering the very product at issue (VERI-TEST ser. 90792753; CALI-MAG ser. 90791185; MAGNATTACK; MAG-RAM; RE80), based at Australian manufacturing-business addresses (Unanderra NSW 2526; Figtree NSW 2525) rather than a US registered-agent service. These are trading entities in a family group, not single-purpose licensing LLCs.

2. Known asserter in the chain — NOT PRESENT. Neither the assignor (Baker, William John) nor either assignee (KR Baker Nominees Pty Ltd, RJ Baker Holdings Pty Ltd) appears on the Acacia / Marathon / Intellectual Ventures / IPNav / Wi-LAN / Mosaid-Conversant / Vringo / Pendrell / MPHJ / Lumen View / Round Rock / Erich Spangenberg lists, and nothing in the chain surfaced on RPX or Unified Patents directories. No reel entry evidences a high-frequency plaintiff.

3. Repeat correspondent across the chain — UNCLEAR / NOT ESTABLISHED. There is only one recorded assignment (reel 069667/0979), so "recurrence across the chain" is not testable, and I could not retrieve the US correspondent for that record. Weak contrary indicator: the same entities' Australian trademark filings use a family-named self-correspondent ("WJ & GM BAKER & WJB NOMINEES PTY LTD"), which is the signature of a family business filing for itself — but I have no US reel entry to confirm or refute this. Flagging as an open verification item, not a finding.

4. Cascading transfers — NOT PRESENT. A single transfer, one hop, executed and recorded in December 2024 — no chained LLC sequence, no cluster of assignments inside 24 months, no shared-agent address pattern.

5. Pre-litigation transfer — NOT PRESENT. The prior sections found no infringement suit naming this patent; with no suit there is no trigger event for this signal, and the 2024 transfer is ~2 years after grant (2022-08-02), not inside a 6-month pre-suit window.

6. Bankruptcy fire-sale — NOT PRESENT. No Chapter 7/11, receivership, or insolvency sale is evidenced for the inventor or either assignee; the group continues to file US trademarks into 2025.

7. Privateering — NOT PRESENT. No operating-company → NPE transfer, no SEC 8-K/10-K disclosure of a patent transfer, and no Patent Progress / EFF coverage of this patent or these entities.

8. Defensive aggregator (anti-NPE) — NOT PRESENT. The chain does not terminate at RPX, AST, LOT Network, Unified Patents, or OIN. It terminates at two family proprietary companies.

Verdict

Operating-company assertion — closest available fit, with the assertion prong expressly not evidenced.

Justification: the entire chain is a single related-party step, executed 2024-12-09 and recorded 2024-12-23 at reel 069667/0979, moving the patent from inventor William John Baker to KR Baker Nominees Pty Ltd and RJ Baker Holdings Pty Ltd — two Australian proprietary companies in the same family-controlled business that does ship products embodying the claims (US trademark ser. 90792753 VERI-TEST: "certified standard magnets used in calibration of Gauss meters"; ser. 90791185 CALI-MAG). Zero NPE signals fire: no shell-entity transfer, no listed asserter, no cascade, no bankruptcy, no privateering, no defensive-aggregator termination. I am selecting the operating-company bucket over "defensive/non-asserting" because the chain terminates at trading companies, not at a defensive aggregator like RPX/AST/LOT — but note the taxonomy mismatch: no infringement suit has been observed on this patent, so it is more precisely operating-company–held and non-litigating, not an active assert.

Two open items to close on the Assignment Center record itself: (a) the correspondent of record for reel 069667/0979, and (b) confirmation that no security-agreement or license records exist in addition to the single assignment — both require reading the record directly.

Verify at: https://assignmentcenter.uspto.gov/ (search "11402442") — legacy mirror: https://assignment.uspto.gov/patent/index.html

I'll research each cited reference from the patent's face. Let me run targeted searches in parallel.

Scope and method note

I retrieved the granted patent's full text/face (US 11,402,442 B2, "Magnetic validation," via its Google Patents/USPTO full-text record keyed to application 17/223,108) and pulled the reference lists. Per the strict rule, I interpreted the number literally as 11402442 (granted as US 11,402,442 B2) and did not substitute near-matching numbers. Note the digit-string hits for unrelated items (e.g., US 11,446,424, US 9,333,946) were excluded.

One structural finding for this task: the patent's face carries exactly one set of five examiner-cited references ("Citations (5)" and "Patent Citations (5)" on the record list the same five documents — there is not a separate set of six or ten). There is also one third-party/family citation, CN 115219960 A, which is not prior art (priority 2022-05-31, later than the '442 priority date) and is therefore excluded from the § 102 analysis below. The "Similar Documents" entries on the page are similarity hits, not citations of record — I did not treat them as prior art of record.

Critical date: the '442 patent claims priority to AU 2020901115 A (2020-04-07), and the record lists a prior-art date of 2020-04-07. All five cited references published years before that date and therefore qualify as prior art under 35 U.S.C. § 102(a)(1) if publicly available.

Caveat up front (important): I do not have the USPTO file wrapper (the actual office actions/IDS/§ 102–103 rejections) in front of me — that requires PatentCenter/PAIR access. So I cannot tell you how the examiner applied each reference; I can only assess, from the granted claim language and each reference's disclosure, whether that reference could anticipate a claim. That is the analysis below.

The five examiner-cited references of record — at a glance

Reference-by-reference analysis

1. US 4,916,392 A — Tiede GmbH & Co. Rissprüfanlagen

• Full citation / dates: US 4,916,392 A; priority 1986-09-17; granted 1990-04-10.
• Description (from the reference's own text): A contactless current-control sensor for magnetoelectric crack detection. A plate-shaped Hall generator (3) is disposed at a set radial distance r from a test-current conductor; the retaining/clamping device has a guide track — "a guide rail or groove" — extending radially, and in one embodiment a retaining plate (13) has a slot (12) perpendicular to the conductor axis so the Hall generator can be slid radially and fixed at a chosen distance. Multiple Hall generators can be pre-fixed at various distances with a switching device.
• Which claim(s) it potentially anticipates — § 102: None fully. Its "guide rail/groove/slot positioning a Hall generator at a fixed point relative to a field source" is the single concept that overlaps with the '442 patent's "guide members to target a nominated magnetic field density" (claim 1) and with claim 7 (guide members align the Hall probe). But US 4,916,392 discloses no standard reference magnet, no second reference magnet derived from a governing reference, no gauss meter, no scanner/camera, and no on-site/remote-validation workflow — i.e., it is missing the majority of every independent claim. Best characterized as § 103 background art against the probe-positioning feature, not an anticipation reference.

2. US 5,663,718 A — Vattenfall AB

• Full citation / dates: US 5,663,718 A; priority 1992-08-11; US application 08/386,493 filed 1995-02-09; granted 1997-09-02 (Unified Patents lists a 1997-09-01 grant date — a one-day source discrepancy, immaterial here).
• Description: A remotely controlled device (carried by helicopter/crane) for automatically measuring physical data at joints in high-voltage lines. It includes a guide-rail steering means, a camera (19) for remotely transferring a picture of the joint and its environs, a means for remote transfer of measurement data to a receiver (fiber-optic/wireless), and a shielding device. Measured quantities are voltage, amperage, and temperature — not magnetic field strength.
• Which claim(s) it potentially anticipates — § 102: None fully. It is the closest art for claims 4–5 ("scanner takes readings of the position of the hall probe and the magnetic field density"; "scanner is a camera") and for the "sending the scan externally" step of claim 6 — its camera-plus-telemetry captures a measurement scene and transmits it off-site. But it discloses no reference magnet, no gauss meter, no Hall probe used for magnet validation, and no validated-then-measure gating. No § 102 anticipation of any claim; possible § 103 combination material on the imaging/remote-transmission feature.

3. US 2005/0258825 A1 — Konica Minolta Photo Imaging, Inc.

• Full citation / dates: US 2005/0258825 A1; priority 2004-05-20; US application 10/990,013 filed 2004-11-16; published 2005-11-24; granted as US 7,132,824 B2 on 2006-11-07. (Slight source variance on the earliest priority date is noted; either way it is far outside any § 102 window relevant to the '442 patent.)
• Description: A magnetic linear-encoder position detector using Hall-effect devices (magnetic sensors) to detect the position of a magnet (a "magnetic force generator"); a controller varies the input values applied to the Hall sensors so the sum of their outputs is held constant, then reads the output difference as a position signal, compensating for piece-to-piece variation of magnets. Applied to a camera-shake compensation mechanism.
• Which claim(s) it potentially anticipates — § 102: None. It shares only generic building blocks — Hall-effect sensing of a magnet and sensor-output compensation/calibration. It has no reference magnet, no gauss meter (it senses position, not field density in gauss), no scanner, no on-site validation. It is, at most, very weak § 103 art on the Hall-sensor/compensation aspect.

4. US 2014/0145710 A1 — Grontmij Nederland B.V.

• Full citation / dates: US 2014/0145710 A1; filed 2011-03-15; published 2014-05-29 (inventor Herman Roelof Noback; related to NL 2006395 C2 / EP 1851522).
• Description: A system for calibrating and measuring the magnetizability of at least a part of a rail. A magnetic-field generator (a substantially saddle-shaped transmitter coil placed partly around the rail) generates a changing field; an induction detector measures a transverse induction; a processing unit determines a "reference induction" representative of the stress-free state (the calibration step) and then determines longitudinal mechanical stress from the longitudinal induction and that reference induction. A mobile device wheels the generator/detector along the rail; a speedometer relates the data to positions.
• Which claim(s) it potentially anticipates — § 102: None fully. This is the closest reference on the workflow idea embedded in claim 6 — establish a reference value by calibration, then use that reference to interpret subsequent field measurements (its "reference induction" ≈ the '442 "governing/reference" concept). But the measured quantity (magnetic induction/rail stress) and the entire apparatus are different, and it lacks a reference magnet, a gauss meter, a Hall probe, a scanner, and external validation. It is § 103 background art at most.

5. US 2019/0011591 A1 — Ebara Corporation

• Full citation / dates: US 2019/0011591 A1; priority 2015-06-29; published 2019-01-10 (assignee Ebara Corporation, Tokyo).
• Description: A metal-detection sensor for detecting metal contaminants in an object under inspection moving through a passageway — permitting the detector section to be as small as ~1 cm, aimed at food/industrial product streams. It uses at least one magnet generating a static field and at least one magnetic-field sensor (magnetoresistive device, Hall device, magnetic-impedance element, or coil) to sense the field perturbation from metal passing through; a reference sensor (120) gives a baseline value when no contaminant is present, and the differential output between the reference and the measurement sensor is used to detect metal.
• Which claim(s) it potentially anticipates — § 102: None fully. It is the most contextually relevant reference — it sits squarely in the food-processing metal-contamination domain that the '442 patent's Background Art describes ("Magnetic separators are used to pull metal fragments from the food…"), and it uses a Hall device plus a "reference" for differential measurement. But it is a contaminant detector, not a reference-magnet validation system: it has no standard reference magnet, no second field-reference magnet taken on site, no gauss meter, no scanner, and no external-validation step. It is background/§ 103 context art, not an anticipation reference.

Overall § 102 conclusion — and where the true risk lies

No one of the five cited references, on its face, discloses every element of independent claim 1 or independent claim 6, so none appears to anticipate under 35 U.S.C. § 102. Each reference supplies at most one element:

• Probe-guide indexing → US 4,916,392 A (guide rail/groove/slot positioning a Hall generator).
• Camera + remote transmission of a measurement scene → US 5,663,718 A.
• Hall-effect sensing + sensor compensation → US 2005/0258825 A1.
• Calibrate-a-reference, then measure against it → US 2014/0145710 A1.
• Food-stream metal detection context + a reference sensor → US 2019/0011591 A1.

The two features that carry the '442 patent's novelty relative to all of these are (i) the "standard reference magnet … a reference magnet for providing a reference based on the governing reference" pairing (a national-traceable governing magnet plus a field-transfer magnet taken to site) and (ii) the scanner-captured, externally-validated reference reading that gates the operator's use of the Hall probe on production magnets (claim 6). None of the five references discloses either, individually or in combination.

Ranking of relevance to the '442 patent:

1. US 2019/0011591 A1 (Ebara) — same industry problem space (metal contamination in food/product streams) plus a Hall device and a reference sensor.
2. US 4,916,392 A (Tiede) — clearest teaching of a guide member that fixes a Hall generator at a repeatable measurement position.
3. US 2014/0145710 A1 (Grontmij) — closest to the "calibrated reference governs later field measurements" logic of claim 6.
4. US 5,663,718 A (Vattenfall) — closest to the camera + remote/off-site data transfer aspects of claims 4–6.
5. US 2005/0258825 A1 (Konica Minolta) — weakest; only generic Hall-sensor/compensation subject matter.

Practical risk read: because none of these is a clean § 102 reference, the meaningful exposure (if any) would be § 103 obviousness — e.g., combining US 4,916,392 A's guided-probe placement with US 2014/0145710 A1's calibrate-a-reference-then-measure approach, and US 5,663,718 A's camera/remote-transmission, in the Ebara food-safety context. That is a combinations question, not anticipation.

Caveats / limits on this analysis

• I mapped claims to references from the granted claim language and each reference's own disclosure; I did not have the actual USPTO office actions or the IDS to see how (or whether) the examiner substantively relied on each of the five. A PatentCenter file-wrapper pull would confirm the examiner's § 102/§ 103 characterizations.
• Dates are taken from the patent's face and the reference records; minor one-day source discrepancies exist (e.g., US 5,663,718 A grant date shown as 1997‑09‑02 on the patent text vs. 1997‑09‑01 on one aggregator). These do not affect the prior-art status.
• I deliberately did not treat the citing document CN 115219960 A (priority 2022‑05‑31) or the "Similar Documents" list as prior art, since neither is an anticipation-capable reference against the 2020‑04‑07 critical date.
• This is a good-faith, claim-element-mapping assessment, not a legal opinion on validity or infringement.

I'll research the specific prior-art references from the patent's citation list to ground the obviousness analysis.

Let me characterize the remaining cited reference and check the AU counterpart's examination posture.

Obviousness Analysis — US 11,402,442 B2 ("Magnetic validation") under 35 U.S.C. § 103

Scope note. The instruction is to use the prior art appearing in the "Prior Art" section of the granted patent's Google Patents record — i.e., the five examiner-cited references (plus, where useful, items in the "Similar Documents" list). I retrieved and verified the disclosure content of four of the five (US 4,916,392; US 5,663,718; US 2014/0145710; US 2019/0011591) and of US 2012/0234109 A1 (which appears in the Similar Documents list rather than the citation list). I was unable to independently verify the disclosure of US 2005/0258825 A1 (Konica Minolta) before hitting my tool-call limit; I flag every statement about it below as unverified. This is a paper analysis of the record, not a validity opinion, and it is not a substitute for a full invalidity search or claim-construction analysis.

1. The legal frame

The application was filed 2021-04-06 claiming AU priority of 2020-04-07, so the AIA § 102/103 framework applies and every cited reference (all published 1990–2019) is prior art under § 102(a)(1). The governing test is Graham v. John Deere as refined by KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398 (2007): (i) scope and content of the prior art; (ii) differences between the prior art and the claims; (iii) level of ordinary skill; (iv) secondary considerations. Under KSR, a combination of known elements is obvious where it does no more than yield predictable results, where there is a design need or market pressure, and where the prior art identifies a finite number of predictable solutions — and the "motivation to combine" need not be found in the references themselves.

Level of ordinary skill (my assumption). A person of ordinary skill here would be a technician/engineer in magnetic-separation and magnetic-field metrology: familiar with gaussmeters/Hall probes, traceable calibration chains (working standard vs. national standard), and the HACCP/QA documentation practices of the food-processing industry that the specification's Background describes.

2. What each cited reference actually teaches

3. Element-by-element mapping of independent claim 1

Note that the preamble's "on site" and element (f) are, on their face, intended-use/functional limitations. Under In re Schreiber and In re Casey, a claim to an otherwise old apparatus is not patentable merely because of a new intended use; the examiner could reasonably treat (f) as adding little if the structure is old.

4. Primary combination: Tiede + KLA '109 + Vattenfall

Rationale. Combine Tiede's indexed Hall-sensor positioning, KLA's gaussmeter/Hall-probe magnet-strength measurement, and Vattenfall's remote, camera-documented, on-site measurement with data offload.

1. Motivation — market pressure stated in the reference/specification itself. The patent's own Background concedes that "a trained technician must go to site, carry out measurements, analyse the results… This is an expensive and labour intensive exercise." Eliminating the travelling technician by shipping a transfer standard and having the site operator measure, photograph and transmit the result is exactly the KSR "design need or market pressure" category.
2. Motivation — recognized source of error. KLA expressly states that probe angle/position variation introduces measurement error; Tiede's slotted guide and retaining device is the predictable, known remedy (position the sensor at an indexed location so "the same Hall generator always gives the same high percentage accuracy"). A POSITA seeking repeatable Hall-probe readings on a reference magnet would look to Tiede's guiding/clamping geometry.
3. Motivation — remote verification is known. Vattenfall already pairs an on-site instrument with a camera and a data link to a remote receiver, which is precisely claim 6's "take a scan… send the scan externally for validation."
4. Reasonable expectation of success. Each element is a routine, off-the-shelf component (gaussmeter, Hall probe, camera, machined collar/slot, shielded case). The combination performs the predictable function of each — no unexpected result is claimed beyond administrative gating.

Result: claim 1 would likely be held obvious over Tiede + KLA '109 + Vattenfall, with the caveat in § 6 regarding the two-magnet limitation.

5. Secondary combination: Grontmij + Vattenfall + Tiede

Grontmij supplies the method logic (establish a reference value from a calibration system; then measure relative to it) and Vattenfall supplies the apparatus deployment logic (portable, on-site, camera-documented, remotely monitored). Grontmij's "reference induction, representative of a stress-free situation," used as the baseline against which field data are judged, is the same abstract scheme as "calibrate a reference magnet; take it to site; measure; get the scan validated externally." A POSITA wishing to extend a field-measurement programme to unqualified personnel on a remote site would predictably bolt Vattenfall's remote-camera/data-link onto Grontmij's reference-based scheme.

6. The strongest non-obviousness argument (and thus the residual gap)

I should flag the weak point of the § 103 case, because an honest analysis must:

• No cited reference discloses a physical reference magnet used as a transfer standard. Grontmij's "reference induction" is a computed baseline, not a magnet; KLA measures magnet strength by force, not by comparing a Hall-probe reading against a known reference magnet; Tiede's "reference" is the geometry of a conductor, not a magnet. The claim's two-tier structure — a standard reference magnet ("governing") and a second reference magnet ("based on the governing reference") — is a metrological traceability chain, and the cited record does not squarely teach a magnet serving as the intermediate working standard for verifying a gaussmeter on site.
• If that two-magnet hierarchy is treated as an integrated system (not merely juxtaposed known parts — cf. In re Ratti / In re Kerkhoven on collocation), a Patent Owner has a respectable argument that the cited art lacks the claimed relationship. The likely reason the examiner allowed after citing only five references (allowance ~12 months after filing) is precisely that the closest art addresses Hall-sensor fixturing, not magnet transfer standards.
• But that gap is probably closable by art outside the cited record. Reference/calibration magnets for verifying gaussmeters, and the general practice of extending traceability from a national standard through a working standard, are well-established metrology concepts. An IPR petitioner would need one such reference (a text, a product datasheet, or another patent) to bridge it. I cannot confirm the existence of a specific such reference from this record.

7. Independent claim 6 (method)

Motivation: the specification's own Background establishes that reports already require "a photograph of each magnet tested and of its relevant location with five gauss meter readings." Turning an existing documentary practice into an emailed scan for pre-authorisation is, on the KSR analysis, the predictable application of a known remote-observation technique (Vattenfall) to a known documentation requirement. The only arguably inventive step — conditioning permission to proceed on remote approval — is a business/administrative rule, not a technical advance, and would add little patentable weight.

Note on the amendment: granted claim 6 recites "taking or sending the reference magnet on site," whereas US 2021/0311142 A1 recited only "taking." Broadening "taking" to "taking or sending" removes any argument that physical transport by the operator is required — which further weakens any distinction over art in which a calibrated artifact is shipped to the measurement location.

8. Dependent claims (all likely obvious)

9. Overall § 103 conclusion

• Claims 2–5 and 7–8: very likely obvious. Each maps essentially one-to-one onto Tiede, KLA '109, or Vattenfall.
• Claim 6: likely obvious over Vattenfall (camera + remote data transfer + on-site portable measurement) in view of KLA '109 and Tiede, once one accepts that the "externally validated" gating step is administrative rather than technical.
• Claim 1: the elements are individually known, and the combination is a predictable assembly of off-the-shelf parts driven by an admitted market pressure — so a strong prima facie § 103 case exists on the cited record. However, the record's weakest link is the two-magnet traceability hierarchy (standard reference magnet governing a field reference magnet). Because no cited reference discloses a magnet as the intermediate working standard, claim 1 is the claim most likely to survive on the cited art alone; a challenge would probably need one additional reference directed to reference/calibration magnets for gaussmeter verification.

Corroborating (non-dispositive) signals: the AU counterpart (AU 2021202022 A1) is recorded as not_active / abandoned while the US case is Active — a modest signal of thin prosecution margin, though abandonment can also reflect commercial strategy, so I would not over-weight it. No litigation, IPR/PGR, or reexamination was found in the prior work on this matter, so there is no adjudicated or institution-stage claim construction to compare against.

10. Explicit uncertainties

1. US 2005/0258825 A1 (Konica Minolta) is unverified in this session — I could not retrieve its disclosure before my tool budget was exhausted. Any reliance on it should be re-checked; from the title alone it appears peripheral.
2. I could not search for a reference-magnet-as-transfer-standard teaching (the missing § 6 bridge) — my earlier searches hit the tool limit. That is the single most important follow-up search for a validity challenge.
3. The mappings above infer the cited references' disclosures from their abstracts, claims, and specification excerpts as retrieved; they are sufficient to state a prima facie case but should be page/paragraph-pinned to each reference's full text before being used in a brief, IPR petition, or invalidity contention.
4. This analysis assumes the AIA applies and treats the AU 2020-04-07 priority date as the effective filing date; if priority were defeated, additional intervening art could enter the field.