US 10492641

I'll search for authoritative information on this patent number and any 2026 litigation activity.

Let me search for the specific litigation docket and any CAFC 2026 activity.

Let me check for any CAFC 2026 appellate docket and confirm the IPR target patent.

US Patent 10,492,641 — Analyst Summary

Scope note / literal-identifier compliance: All findings below are for the exact identifier 10,492,641 (US 10,492,641 B2). Where a search hit referenced a different but related number (e.g., 10,852,002; 9,980,322), I flag it explicitly rather than folding it into this summary. A targeted CAFC search for 10,492,641 / 10492641 returned no Federal Circuit appellate docket; I have no authoritative evidence of a 2026 CAFC appeal involving this patent. Treat that as "not found," not "confirmed none."

Bibliographic Data

Continuity: Application 15/985,255 is a continuation of US App. 15/133,220 (filed Apr. 19, 2016; granted as US 9,980,322 B1). It has one continuation child, US 16/403,415 (filed May 3, 2019; granted as US 10,841,981 B1). Family ID 62125512.

Classification: A47J 36/2483; A47J 36/2488; A47J 39/006; F24C 7/043; F24C 15/16; F24C 15/18; H05B 3/0076. Google Patents also flags the family as having litigation.

Sources: https://patents.google.com/patent/US10492641/en ; https://wiki.golden.com/wiki/US_Patent_10492641_Multi-zone_food_holding_bin-P43PW3W

Abstract (verbatim)

"A multi-zone food holding bin has a continuous food supporting surface with multiple food holding zones. Each food holding zone is independently controllable so that different food temperatures may be maintained in adjacent food holding zones."

Plain-Language Overview of the Independent Claim

Claim 1 (the sole independent claim; claims 2–34 all depend, directly or indirectly, on claim 1) covers a heated holding cabinet with this combination:

1. Cabinet structure. A chassis with a top panel, two side panels, a bottom panel, an open front face, and an opposing rear face.

2. Two stacked heated compartments.

   • The upper compartment is bounded by the side panels, the top panel, and an intermediate shelf, and is "substantially unobstructed" between the side panels and below a downwardly depending lid-holding shelf formed in the top panel.
   • The lower compartment sits below it, bounded by the side panels, the bottom panel, and that same shelf, likewise "substantially unobstructed" below a downwardly depending lid-holding shelf formed in the shelf.

3. Thermally conductive planar food-support surfaces. The shelf's upper face is a substantially planar thermally conductive surface forming the upper compartment's bottom (tray-receiving) surface; the bottom panel's upper face is a second substantially planar thermally conductive surface forming the lower compartment's bottom (tray-receiving) surface.

4. Four openings — pass-through on both faces. Two openings in the front face and two in the rear face, each bounded by the relevant planar surface and side panels, all sized to let a food tray pass through. This gives the front-to-back "pass-through" capability.

5. Four independently controlled holding zones. Two zones in the upper compartment and two in the lower. Every zone has at least one independently controllable heating element at the top portion of its compartment and at least one at the bottom portion, plus its own controllable holding temperature (first/second/third/fourth).

6. User interface + controller. At least one user interface for setting each zone's temperature, and a controller operatively coupled to that interface and to every heating element, configured to independently operate each element so each zone holds an independently controlled temperature.

Practical gist: a two-tier warming/pass-through cabinet whose shelf surfaces are continuous and undivided, with heat sources above and below each of four side-by-side zones, each zone individually temperature-controlled from a shared bezel/interface. The specification's stated benefit is holding different foods at different ideal temperatures in the same compartment (e.g., french toast, eggs, sausage, hash browns), extending palatability time "by a factor of two or more," and easy cleaning because the support surfaces are free of dividing walls.

Note on claim-scope caution: Search results surfaced a closely related but distinct patent, US 10,852,002 B1, whose independent claims recite different features (e.g., "food holding bays," "radiant/conductive" limitations, a method claim). Those are not the claims of 10,492,641 and should not be attributed to it.

Litigation / PTAB Context (as found)

• District court: Marmon Foodservice Technologies, Inc. v. Duke Manufacturing Co., No. 4:25-cv-01491 (E.D. Mo.), Nature of Suit 830 — Patent, Cause 35 U.S.C. § 271, filed 2025 (PacerMonitor lists a 2025 filing date; the Google Patents family page links this same case as family litigation).
  Source: https://cdn.pacermonitor.com/public/case/60445383/Marmon_Foodservice_Technologies,_Inc_v_Duke_Manufacturing_Co
• IPR (different patent — flagged): IPR2026-00406, Duke Mfg Co v. Marmon Foodservice Technologies Inc, lists respondent patent number 10,852,002 — i.e., the sibling patent, not 10,492,641. A separate IPR2026-00479 (Duke v. Marmon) appears with a 2026 filing date; the search result did not identify its target patent.
  Sources: https://ipverse.greyb.com/ptab-web/cases/case-details/IPR2026-00406 ; https://ai-lab.exparte.com/case/ptab/IPR2026-00479/duke-mfg-co-v-marmon-foodservice-technologies-inc

Explicit Uncertainties

• Date inconsistency in the source record: The task prompt states the current date as April 26, 2026, but several retrieved pages carry later timestamps (e.g., an IPR listed as filed 07/02/26 and a tracker "last updated Sep 22, 2026"). I am reporting dates exactly as retrieved and have not reconciled them.
• Asserted patents not confirmed: I did not retrieve the complaint in 4:25-cv-01491, so I cannot confirm that 10,492,641 is among the asserted patents — only that Google Patents associates this family with that case.
• No CAFC docket located: My search for a 2026 Federal Circuit appeal tied to 10,492,641 returned nothing on point. I do not have authoritative information confirming any appellate proceeding for this specific patent.
• Assignee history: The change of assignee to Marmon Foodservice Technologies, Inc. is recorded as a merger/change of name involving Cornelius, Inc. and Prince Castle LLC (Jan. 26, 2021); the current-assignee listing is stated by Google Patents to be an assumption, not a legal conclusion.

Primary source of record: https://patents.google.com/patent/US10492641/en

I'll search for litigation specifically involving US 10,492,641, being careful to exclude similar numbers.

Let me search more specifically for the known case and any docket listing asserted patents.

Let me check the Unified Patents litigation portal and look for the complaint's asserted patents, plus any other Marmon enforcement.

Litigation involving US 10,492,641

I searched for the exact identifier 10492641 / 10,492,641 on patent‑litigation sources (Google Patents family litigation entry, Unified Patents litigation portal, PacerMonitor, Justia Dockets, Docket Alarm). Here is what the record actually shows.

Known case (from the patent's own family-litigation entry)

Sources:

• Google Patents family‑litigation entry for the patent (Unified Patents link to "Missouri Eastern District Court, case 4:25-cv-01491"): https://patents.google.com/patent/US10492641/en
• PacerMonitor docket: https://cdn.pacermonitor.com/public/case/60445383/Marmon_Foodservice_Technologies,_Inc_v_Duke_Manufacturing_Co
• Justia Dockets (E.D. Mo., NOS 830): https://dockets.justia.com/search?noscat=10&page=5&sort-by-last-update=true&state=missouri

Important limitation — read this before relying on the case

I could not retrieve the complaint or any docket document that expressly lists U.S. 10,492,641 among the asserted patents. The association above comes from the patent's Google Patents family‑litigation field (which links that case), not from a face‑of‑the‑complaint patent list. So I can confirm the case exists, its parties, court, number and subject matter — but I cannot confirm from primary sources that 10,492,641 is one of the patents-in-suit. Treat "the '641 patent is asserted in 4:25-cv-01491" as unverified until the complaint (Dkt. 1) or an infringement contentions chart is pulled from PACER.

No other litigation found

• No other district-court case was located naming the '641 patent. Searches for the number returned no second lawsuit, and no ITC Section 337 investigation appeared.
• No CAFC appeal tied to this patent was found (the E.D. Mo. case is pending at the district court, so nothing is appealable yet).
• Do not conflate adjacent proceedings. IPR2026‑00406 (Duke Manufacturing Co. v. Marmon Foodservice Technologies, Inc., filed Jul 1, 2026) targets U.S. 10,852,002 — a different patent number — not 10,492,641. Per the strict-identifier rule, that proceeding is not litigation involving 10,492,641.
• The aggressive § 271 enforcement campaign between Marmon/Prince Castle and Duke is broader than this patent: LTI (Low Temp Industries) v. Duke (E.D. Mo. 4:20‑cv‑00686, plus IPR2021‑00412/‑00414/‑00415) belongs to the same competitor dispute but concerns different patents (e.g., 8,307,761; 8,661,970; 9,795,253) and a different patent owner. I flag it only as context; it is not a 10,492,641 case.

Flagged contradiction with the previously generated sections

The previously generated "PTAB challenges" section states there is an IPR2026‑00480, Duke v. Marmon, filed 2026-09-30, against this patent. That conflicts with the date given for this task (April 26, 2026) — a proceeding could not have been filed on 2026-09-30 if today is 2026-04-26. I have not repeated or relied on that entry here. I also could not independently retrieve IPR2026‑00480 in this session. For litigation purposes it is in any event a PTAB proceeding, not district-court litigation, and must not be counted in the table above.

Bottom line

One litigation matter is associated with US 10,492,641: Marmon Foodservice Technologies, Inc. v. Duke Manufacturing Co., No. 4:25-cv-01491 (E.D. Mo.), a § 271 infringement action between direct commercial competitors, pending with no reported outcome. Whether the '641 patent is actually an asserted patent in that case is not confirmed on the primary record I could access — verify via PACER (Dkt. 1 and the infringement contentions). No other litigation and no appellate proceeding involving this exact patent number were found.

Confidence: high on the case's existence, parties, court, number, cause and status (corroborated by PacerMonitor + Justia + the patent's family‑litigation link). Low/unverified on whether 10,492,641 is a patent-in-suit, and on the exact calendar filing date (2025-??-03; likely July 3, 2025).

I'll research the PTAB proceedings for this patent, starting with the canonical proceeding and any claim-level outcomes.

Let me dig deeper into the specific proceeding and check PTAB dockets.

Let me search for the specific proceeding number and its target patent.

AIA Trial Proceedings — US 10,492,641 B2 ("Multi-zone food holding bin")

Sourcing note. The proceedings list below is taken from the structured "PTAB proceedings on file" block (USPTO Open Data Portal), which I treat as canonical ground truth. I have not added proceeding numbers. Where my web searches surfaced other Duke/Marmon AIA filings, I flag them explicitly as not on this patent and do not count them. Today's date is 2026-09-30, which is material: the sole proceeding on this patent was filed today.

Proceedings overview

One AIA trial proceeding is on file for US 10,492,641 — IPR2026-00480, filed 2026-09-30 and still "Pending"; zero claims have been canceled or sustained, no institution decision, FWD, settlement, or appeal exists, so the patent is entirely untested at the PTAB and a defendant today has no claim-level estoppel or cancellation record to leverage — only a brand-new, high-risk § 315(b)/§ 314(a) battleground that will not produce an institution decision before roughly 2027-03-30 or a final written decision before roughly 2028.

Breakdown: active/pending = 1; claims invalidated = 0; claims sustained = 0; settled = 0; institution denied = 0.

IPR2026-00480 — Duke Manufacturing Co. v. Marmon Foodservice Technologies, Inc.

• Type: Inter Partes Review (IPR).
• Filed: 2026-09-30 (structured data: filed 2026-09-30; last modified 2026-09-30).
• Status: Pending (verbatim from the structured block) — gloss: the petition was docketed today; no preliminary response, no § 314(b) decision, no panel merits work exists on the public record.
• Judge panel: Not yet public / not assigned. No APJ names appear in the structured data; sister 2026 Duke/Marmon dockets still show "Pending Judge Assignment." I will not guess panel composition.
• Petition grounds: Not yet public on the record I could retrieve. The petition is one day old. I did not obtain the challenged-claim list, the asserted art, or the statutory basis (§ 102 / § 103 / § 112). Non-fabrication constraint applies — I am not inferring grounds from the sibling IPRs into this docket. Note for planning only: grounded in the patent's own cited art (e.g., US 5,724,886; US 6,175,099; US 6,119,587; US 2011/0030565), the natural attack on claim 1 is a § 103 combination aimed at the "four zones × independently controlled top-and-bottom elements + continuous planar pass-through shelf" combination — but that is my analytical expectation, not the filed ground.
• Institution decision: None issued. Statutory deadline under 35 U.S.C. § 314(b) is no later than six months after filing → by ~2027-03-30.
• Final Written Decision: None. Under § 316(a)(11), an FWD is due within 12 months of institution (extendable to 18 for good cause) — i.e., ~2028-03 at the earliest if instituted.
• Settlement / termination: None on file. No termination, no adverse judgment, no request for adverse judgment.
• Appeal: None. Nothing is appealable pre-institution; no Federal Circuit docket exists for this patent.
• Defensive value: For a defendant today, this proceeding is a signal, not a shield. Nothing is canceled, so every claim 1–34 remains live and presumptively valid; there is no § 315(e)(2) estoppel yet (estoppel attaches only after an FWD, and § 315(e)(1) IPR estoppel does not bind the petitioner until then either). Two live questions dominate the defensive posture: (1) timeliness — if Duke was served in the E.D. Mo. case in mid-2025, a 2026-09-30 petition is facially more than one year after service and vulnerable to a § 315(b) time-bar argument as to this patent unless the '641 patent was injected into the case by later pleading; (2) discretionary denial — the patent issued 2019 and the litigation is live, so Patent Owner will likely press § 314(a) (Fintiv-type) and settled-expectations arguments. Neither is resolved.

Strategic summary

Claim status: no PTAB narrowing whatsoever. All 34 claims of 10,492,641 are UNTESTED at the Board. Zero CANCELED, zero SUSTAINED. There is no surviving-claims list to cite because no claim has been adjudicated — the aggregate public record on this patent is a single same-day petition. Anyone asserting claims 1–34 today faces no PTAB estoppel and no cancellation history. That also means the patent is not "hardened" and not "broken" — it is simply un-adjudicated.

Estoppel landscape. Because no IPR on this patent has reached an FWD, § 315(e)(2) estoppel has not attached to anyone on the '641 patent. For a defendant currently asserted (and note the unusual alignment: Duke is both the petitioner here and the defendant in Marmon v. Duke, No. 4:25-cv-01491, E.D. Mo.), the full menu of § 102/§ 103 prior-art grounds remains available in district court today. If IPR2026-00480 is instituted and runs to an FWD, Duke would then be estopped from relitigating in the litigation any ground it raised or reasonably could have raised — but a non-petitioner co-defendant (or an entity not in privity with Duke) would not be bound by Duke's estoppel (subject to privity/RPI analysis). Separately, watch § 315(b): the one-year clock runs per-patent from service of a complaint alleging infringement of that patent.

Pattern signals. (a) Same petitioner, multiple filings — Duke has filed at least four PTAB cases per IP Verse (last updated 2026-09-17), and the searches surfaced a same-day companion, IPR2026-00481 (Duke Manufacturing Co., filed 09/30/26, Pending) — but the structured block lists only IPR2026-00480 for this patent, and I could not tie -00481's target to 10,492,641, so it is excluded from the count here. (b) Adjacent patent, not this one — IPR2026-00406 (Duke v. Marmon, filed 2026-07-01/02) targets US 10,852,002 (respondent app. 16/403,349), a different patent number; it is not a 10,492,641 proceeding and must not be conflated (strict-identifier rule). (c) Patent owner aggressiveness — Marmon is the plaintiff enforcing its own operating-company patents, not an NPE; no defensive aggregator (Unified/RPX/AST) appears in the chain. (d) No PTAB appeal activity for this patent — nothing is ripe.

Flagged contradiction, now resolved. The earlier "Litigation summary" section flagged that the "PTAB challenges" block dated IPR2026-00480 to 2026-09-30, which conflicted with that task's stated date of 2026-04-26. With today's date now 2026-09-30, that conflict dissolves: the proceeding was filed today, and the earlier April-26 date was the stale/inconsistent value. No correction to the proceeding number is needed.

Recommended next steps

1. Do not rely on any PTAB cancellation for US 10,492,641 — there is none. If a demand letter cites claims 1–34, the ordinary invalidity defenses remain fully available; there is no FWD to quote and no canceled claims to point to.
2. Pull the IPR2026-00480 papers as soon as they post (petition, statutory-grounds table, exhibit list) and calendar: POPR (§ 313), § 314(b) institution deadline ~2027-03-30, and, if instituted, FWD ~2028-03 under § 316(a)(11). Monitor via PTAB E2E / PTAB Center (https://ptacts.uspto.gov/ptacts/) and a commercial docketing mirror (e.g., Docket Alarm).
3. Preserve the § 315(b) timeliness theory and the § 314(a) discretionary-denial theory — these are the two issues most likely to dispose of the petition before institution. Confirm the service date in Marmon v. Duke, No. 4:25-cv-01491 (E.D. Mo.), and whether the '641 patent was pleaded in the original or an amended complaint; the case docket is tracked at the Unified Patents portal: https://portal.unifiedpatents.com/litigation/Missouri%20Eastern%20District%20Court/case/4%3A25-cv-01491
4. Verify the adjacent filings individually rather than by inference — confirm the target patents of IPR2026-00481 (Duke, filed 2026-09-30) and IPR2026-00406 (Duke, filed 2026-07-01/02, target US 10,852,002). Only proceedings whose respondent patent is 10,492,641 belong in this analysis; per the canonical list, that is IPR2026-00480 alone.
5. CourtListener (https://www.courtlistener.com/) is the place to watch for any future Federal Circuit appeal; none exists for this patent as of 2026-09-30.

Confidence: high that IPR2026-00480 is the only AIA proceeding on this patent and that it is pending with no merits record (structured block is canonical and corroborated as a same-day filing). Low / not established on the petition's grounds, challenged claims, and panel — none are public yet — and not verified on the exact § 315(b) service date.

I'll research the assignment record for US 10,492,641, starting with the USPTO Assignment Center and cross-referencing legal events.

Let me search for the specific assignment records and correspondents.

Let me pull the specific assignment records with reel/frame data.

Assignment & Ownership Analysis — US 10,492,641 B2

Sourcing note (important). I retrieved the assignment activity from Google Patents' USPTO-derived legal-events record for the patent's family page and an indexing hit at plainsite.org ("Patent Assignment from Prince Castle LLC; and Cornelius, Inc. to Marmon Foodservice Technologies, Inc.," assignment id 10443950). I was unable to retrieve the USPTO Assignment Center reel/frame numbers or the correspondent-of-record fields within this session (the search budget closed before the Assignment Center detail pages loaded). I therefore report the events and parties that are documented, and I have left reel/frame and correspondent marked "not retrieved" rather than guessing. Do not treat any blank reel/frame below as a fabricated value.

Inventors

Pattern check. No "unusual pattern" signal is present on the record I can access. There is no evidence of inventors departing within 12 months of filing, and Hartfelder's ongoing filings with the same corporate family cut against an inventor-departure/fire-sale narrative. Caveat: employment is inferred from the assignment to Prince Castle LLC plus inventor address-of-record; I did not retrieve each inventor's signed employment agreement.

Original assignee

Prince Castle LLC (recorded assignee on the 2018-07-24 assignment; also the applicant of record on the filed application).

• Line of business: commercial foodservice equipment — hot food holding bins/cabinets, toasters, slicers, timers, grills (see Marmon's 2013 corporate brochure describing the Foodservice Technologies sector).
• Did they ship a product embodying the claims? Yes — strong evidence. Marmon Foodservice Technologies' § 287(a) virtual patent-marking page lists "Prince Castle | Holding Bins | EHBXX and EHBTHXX, XX = 23, 24, 34" and "Modular Holding Bins (MHB)" — i.e., the family markets a multi-zone holding-bin product line under the Prince Castle brand. Source: https://www.marmonfoodservice.com/fr/patents
• Current status: Operating, not dissolved/acquired-in-distress. Prince Castle LLC is a subsidiary within Marmon Holdings, Inc. (a Berkshire Hathaway company); it was merged into Marmon Foodservice Technologies, Inc. in the 2021 event below (per onscope, Prince Castle LLC's parent is listed as Marmon Food Beverage & Water Technologies Co LLC).

Assignment timeline

(Reel/frame and correspondent fields: not retrieved in this session. Events and parties are taken from the USPTO-derived legal-events record.)

• 2018-07-24 recorded — Reel not retrieved / Frame not retrieved

  • Conveyance: Assignment of Assignors' Interest (inventor-to-company assignment)
  • Assignor: Kestner, Kyle Thomas; Lyons, Christopher B., Jr.; Hartfelder, Charles B.; McCoy, Zachary N. (the four named inventors)
  • Assignee: Prince Castle LLC
  • Correspondent: not retrieved
  • Context: Standard inventor-to-employer assignment, recorded ~2 months after the 2018-05-21 filing — routine prosecution housekeeping, not an acquisition.

• 2021-01-26 recorded — Reel not retrieved / Frame not retrieved

  • Conveyance: Merger and Change of Name
  • Assignor: Cornelius, Inc. and Prince Castle LLC
  • Assignee: MARMon Foodservice Technologies, Inc. (Marmon Foodservice Technologies, Inc.)
  • Correspondent: not retrieved
  • Context: Internal corporate reorganization — the two Marmon foodservice operating subsidiaries (Cornelius and Prince Castle) merged/renamed into Marmon Foodservice Technologies, Inc. This is a name/entity change of the same beneficial owner (Marmon/Berkshire Hathaway), not a transfer to a third party, licensing vehicle, or asserter. Source: Google Patents legal events ("Assigned to MARMON FOODSERVICE TECHNOLOGIES, INC. — MERGER AND CHANGE OF NAME … Assignors: CORNELIUS, INC., Prince Castle LLC").

No other recorded assignment was located for this patent. There is no security agreement, license, release, correction, or third-party transfer on the record I could access.

Timeline diagram

timeline
    title Ownership of US 10492641
    2016 : Priority date for the family
    2018 : Continuation applied for by Prince Castle
         : Inventors assign rights to Prince Castle LLC
    2019 : Patent US 10492641 issued
    2021 : Merger into Marmon Foodservice Technologies
    2025 : Marmon sues Duke Manufacturing for infringement

NPE / troll-pattern signals

1. Shell-entity transfer — Not present. The only non-inventor transfer is the 2021-01-26 merger/change-of-name into Marmon Foodservice Technologies, Inc., an operating company within Marmon Holdings/Berkshire Hathaway. No "IP / Licensing / Holdings / Ventures" shell, no registered-agent-only address, and no single-purpose LLC appears in the chain. Marmon markets embodying holding-bin products under the Prince Castle brand.

2. Known asserter in the chain — Not present. Neither Prince Castle LLC nor Marmon Foodservice Technologies, Inc. matches any entry on the public NPE lists named in the brief (Acacia, Marathon, Intellectual Ventures, IPNav, Wi-LAN, Conversant/Mosaid, Vringo, Pendrell, Round Rock, etc.). Both are operating commercial-equipment manufacturers.

3. Repeat correspondent across the chain — Unclear / not determinable. I could not retrieve the correspondent-of-record for either recording, so I cannot assess recurrence of a single filing attorney across the chain. This signal is therefore undetermined, not negative — it should be re-checked in the Assignment Center.

4. Cascading transfers — Not present. Only two recorded events span the life of the patent (2018 and 2021), and only one is an ownership-conveying change of entity. There is no rapid succession of chained LLCs, no shared correspondent address pattern available to test, and no common-principal red flag.

5. Pre-litigation transfer — Not present. The last ownership event is 2021-01-26; the associated infringement action (Marmon Foodservice Technologies, Inc. v. Duke Manufacturing Co., No. 4:25-cv-01491, E.D. Mo.) was filed 2025. The gap is roughly 4.5 years, far outside the 6-month window that would indicate a chain arranged to enable assertion. The patent was already owned by the operating company years before suit.

6. Bankruptcy fire-sale — Not present. No Chapter 7/11 proceeding and no sale-in-bankruptcy involving Prince Castle LLC or Marmon Foodservice Technologies, Inc. was located; the transfer was a solvent internal merger.

7. Privateering — Not present. Marmon is the operating company asserting its own patents directly as plaintiff, not transferring to an NPE to assert on its behalf. (The suit is Marmon v. Duke, competitor-vs-competitor.)

8. Defensive aggregator (anti-NPE) — Not present. The chain does not terminate at RPX / AST / LOT / Unified / OIN. Ownership stays with the operating manufacturer.

Verdict

Operating-company assertion.

Justification: The chain shows only a routine inventor-to-Prince Castle LLC assignment (recorded 2018-07-24) and a solvent merger/change-of-name into Marmon Foodservice Technologies, Inc. (recorded 2021-01-26) — no licensing shell, no asserter, no cascading LLC transfers, and no pre-litigation repositioning (the 2021 entity change precedes the 2025 complaint by ~4.5 years). The current owner is a Marmon/Berkshire Hathaway operating subsidiary that ships embodying holding-bin products (Prince Castle EHB/MHB lines per its § 287(a) marking page) and is suing a direct commercial competitor (Duke Manufacturing) — the classic operating-company enforcement posture, not an NPE.

Confidence: High on the verdict. Moderate on completeness of the chain — because I could not open the Assignment Center detail pages, the reel/frame numbers and correspondents remain unretrieved, and a diligent analyst should confirm whether any security agreement or license recording (which would not change beneficial ownership but would appear on the record) sits between the two events.

Verification links:

• USPTO Assignment Center (search by patent number 10492641): https://assignmentcenter.uspto.gov/
• Legacy index: https://assignment.uspto.gov/patent/index.html
• Corroborating indexing hit: https://www.plainsite.org/patents/assignment.html?id=10443950
• Patent legal events: https://patents.google.com/patent/US10492641/en

Flags carried forward: (a) The previously generated sections note the date inconsistency (task header April 26, 2026 vs. session/environment 2026-09-30); this assignment analysis is date-agnostic and unaffected. (b) Whether US 10,492,641 is actually an asserted patent in 4:25-cv-01491 remains unverified — but that does not change the ownership verdict, since the ownership chain does not depend on the suit.

I'll ground this in the actual citation record for US 10,492,641 and verify the key references via targeted searches.

Let me verify a few more high-relevance citations from the patent's list.

Prior-Art Analysis for U.S. Patent No. 10,492,641 — § 102 Anticipation Focus

Scope / strict-identifier compliance. This report is for the exact identifier 10,492,641 (US 10,492,641 B2, "Multi-zone food holding bin," app. 15/985,255). I did not substitute or fold in any similar number. Where a search surfaced a different but related number (9,980,322; 10,841,981; 10,512,363; 10,852,002), I flag it explicitly and exclude it from the anticipation analysis — several of these are same-family members and therefore not prior art at all (see §5).

Database note. The authoritative claim set and the examiner's citation list for 10,492,641 are the ones reproduced on the patent's official record (Google Patents mirror of USPTO data, https://patents.google.com/patent/US10492641/en). That record lists ~160–192 cited references, the great majority of which are only tangentially related (1940s–1980s refrigerators, vending machines, restaurant management systems, POS computers). Per the task, I identify the most relevant references and analyze each for § 102 purposes; the peripheral references are noted collectively in §4 rather than one-by-one, because none is a serious anticipation candidate.

Build-on note. The previously generated Obviousness (§ 103) section already mapped these references element-by-element for a § 103 combination. This section does not repeat that element map; it re-frames the same (and a few additional) references under the stricter § 102 single-reference standard, which is the correct question here.

1. The § 102 standard applied here

Anticipation under 35 U.S.C. § 102 requires that a single prior-art reference disclose every limitation of the claim, arranged as in the claim — no picking and choosing across references, and no reliance on the patentee's own recognition of the problem. A dependent claim is anticipated only if the reference discloses all limitations of the base claim plus the added limitation (a dependent claim carries every limitation of the claim from which it depends).

Consequence for this patent: claim 1 is the sole independent claim and is a narrow combination — two stacked compartments; a continuous, undivided, thermally conductive tray-support surface in each compartment; four zones, each with independently controllable heating elements at both the top and the bottom of its compartment; four pass-through openings (two front, two rear); and a "downwardly depending lid holding shelf" formed on the top panel and on the shelf. As explained below, no single cited reference discloses all of these, so, strictly, no reference fully anticipates claim 1 — and therefore no reference fully anticipates claims 2–34 either. Several references, however, are the strongest single-reference (near-anticipatory) art for particular limitations, and are the primary references any § 102/§ 103 challenge would be built on. I give both the strict answer and the practical "claims most relevant to" mapping for each.

2. Tier 1 — References that come closest to anticipating claim 1

2.1 US 2011/0283895 A1 (Veltrop) — the single closest reference

2.2 US 5,724,886 (Ewald et al.) — strongest "pass-through + top-and-bottom independent heating" reference

2.3 US 2004/0020915 A1 (Shei) / U.S. Pat. No. 7,227,102 — the "radiant top + conductive bottom, independently controlled compartments" reference

2.4 US 7,385,160 B2 (Jones) — the "two compartments, four tray locations, suspended covers" reference

3. Tier 2 — References most relevant to specific dependent-claim limitations

3.1 US 2009/0266244 A1 (Maciejewski et al.) — "compartment heated above and below, retained covers"

• Full citation: U.S. Pub. No. 2009/0266244 A1, "Post-supported covers for food trays," Maciejewski et al.; U.S. Pat. No. 8,091,472 B2; assignee Prince Castle.
• Dates: Pub. Oct. 29, 2009; granted Jan. 10, 2012.
• Description: Food warmer whose compartments are heated from above and below by heater plates, with covers (lids) retained/suspended inside the compartment above the tray location and per-compartment interface bars for temperature/hold-time.
• § 102 relevance: Most relevant to claims 21, 24, 25 (elevated lid-holding shelf; sheet-metal lid shelf) and claims 2, 9 (per-compartment display/controls). Does not anticipate claim 1.

3.2 US 2008/0302778 A1 (Veltrop) — "cover with horizontal + vertical section retained in compartment"

• Full citation: U.S. Pub. No. 2008/0302778 A1, "Apparatus and Method for Maintaining Cooked Food in a Ready-to-use Condition," Veltrop; assignee Prince Castle. (A same-title grant, U.S. Pat. No. 7,858,906 B2, issued Dec. 28, 2010; I flag below that its inclusion in the '641 citation list is not confirmed in this session.)
• Dates: Pub. Dec. 11, 2008; grant date Dec. 28, 2010 (not independently re-verified here).
• Description: Cover having a horizontal section and a downwardly extending vertical section, removably mounted on a support member in the heating compartment, cooperatively defining a receiving space for a tray.
• § 102 relevance: Most relevant to claims 21–25 (lid/cover retention and mounting). Does not anticipate claim 1.

3.3 US 2009/0126580 A1 (Hartfelder et al.) — "removable divider"

• Full citation: U.S. Pub. No. 2009/0126580 A1, "Removable Divider For Food Warming Apparatus," Hartfelder et al.; assignee Prince Castle.
• Dates: Pub. May 21, 2009.
• Description: Dividers for a food-warming compartment are removable/optional.
• § 102 relevance: Directly relevant to the negative limitations of claims 19–20 ("continuous surface"; "substantially free of any dividing walls"). A reference teaching that dividers are removable does not, standing alone, disclose a surface actually free of dividers, so it is not anticipatory of claims 19–20 — it is an obviousness reference.

3.4 U.S. Pat. No. 6,175,099 B1 (Shei & Luebke) — "front and rear aligned openings, independently controlled heaters"

• Full citation: U.S. Pat. No. 6,175,099 B1, "Holding or cooking oven," Steven M. Shei & Clement J. Luebke; assignee Duke Manufacturing Co. (reissue RE40,290).
• Dates: App. 09/538,761 filed Mar. 30, 2000; granted Jan. 16, 2001.
• Description: Cabinet with tiers of aligned front and rear openings 36 for tray pass-through, channel-shaped aluminum heat sinks heating tray bottoms and sides, and a control in which (per the RE40,290 claims) each heater's operation is controlled independently, or at least one group independently of another.
• § 102 relevance: Most relevant to the front/rear opening limitations of claim 1 and to claims 33–34 (independently set/maintained per-zone temperatures). Does not anticipate claim 1 (no top-and-bottom per-zone arrangement, no lid shelf, no continuous open two-zone compartment).

3.5 Control / temperature-sensing references (expressly incorporated into the '641 specification)

• US 2011/0114624 A1 (Chung et al.), "Food Holding Cabinet Power Supplies with Downloadable Software," pub. May 19, 2011, Prince Castle — expressly incorporated by reference in the '641 specification for microprocessor/downloadable-software control.
• U.S. Pat. No. 8,247,745 B2 (Chung et al.), "Temperature Sensor for a Food Holding Cabinet," granted Aug. 21, 2012, Prince Castle — expressly incorporated by reference for the semiconductor plate temperature sensor.
• § 102 relevance: Most relevant to the controller element of claim 1 and to claims 33–34. Neither anticipates claim 1.

4. Tier 3 — References relevant to isolated limitations (not anticipation candidates)

These are cited on the '641 face but disclose only discrete features and cannot anticipate claim 1 under § 102:

The remaining ~140 cited references (e.g., US 2,386,919 (1945 refrigerator), US 2,900,806, US 4,098,041, US 5,069,273, the Food Automation/Integrated Controls restaurant-management and cooking-computer patents, US 5,818,020 "Food shelving and cycling system," etc.) are not serious § 102 art for claim 1 and are not analyzed individually.

5. Same-family / related-number items that are NOT prior art (do not use)

• U.S. Pat. No. 9,980,322 B1 — the parent of 10,492,641 (app. 15/133,220, filed Apr. 19, 2016). Same family; not prior art.
• U.S. Pat. No. 10,841,981 B1 — the continuation child (app. 16/403,415, filed May 3, 2019). Not prior art.
• US 10,512,363 B2 ("Multi-zone food holding bin," app. 15/984,760, filed 2018-05-21, same inventors/assignee) — surfaced in search as a sibling application, not on the '641 family table (a source-record inconsistency). It is a related/same-owner application, not prior art.
• US 10,852,002 B1 — a separate patent number (the target of the earlier-flagged IPR2026-00406). Not 10,492,641 and not prior art here.

6. Bottom line for § 102

Net: On the record I can access, no cited reference anticipates claim 1 or any dependent claim of 10,492,641 under § 102. The patent's invalidity exposure lies in § 103 (see the previously generated Obviousness section), where Veltrop '895 + Shei '915 (Duke) + Jones '160 / PC '472 supply essentially every claim-1 limitation except the "downwardly depending" lid-shelf mounting and the divider-free negative limitation — both of which the '641 specification's own cleanability rationale and US 2009/0126580 A1 (removable dividers) tend to render obvious.

7. Explicit uncertainties / flags

1. Breadth of the citation list. The '641 record lists 160 (per one rendering) to 192 (per another) cited references; I analyzed the ~15 most relevant and grouped the remainder. A complete one-by-one treatment of all 160–192 is not provided, and none of the unlisted remainder is a plausible claim-1 anticipation reference.
2. Publication-to-grant mappings. For the Duke family I cite US 2004/0020915 A1 as it appears on the '641 face and note US 7,105,779 / US 7,227,102 / US 7,328,654 as family grants; I did not confirm a strict one-to-one application correspondence for every grant and have not asserted one.
3. US 7,858,906 relation. The "Apparatus and Method for Maintaining Cooked Food in a Ready-to-use Condition" grant (US 7,858,906 B2, Dec. 28, 2010) shares title/inventor lineage with US 2008/0302778 A1; I have not confirmed that the '641 citation list includes the grant, so I treat only the published application as confirmed art.
4. Strict vs. practical reading. I applied the strict § 102 rule (dependent claims require all base-claim limitations). Analysts sometimes loosely list "claims a reference could anticipate" meaning "limitations it discloses"; where I map references to claim numbers in §2–§3, that is a limitation-relevance map, not a legal conclusion that those claims are anticipated.
5. Date-header inconsistency (carried forward). The task header states April 26, 2026, while other parts of this project state 2026-09-30. This § 102 prior-art analysis is date-agnostic (all references predate the Apr. 19, 2016 priority date on any reading), so the discrepancy does not affect the conclusions.
6. No auto-correction applied. All identifiers — 10,492,641; 2011/0283895; 8,522,675; 5,724,886; 6,607,766; 2004/0020915; 7,105,779; 7,227,102; 7,328,654; 7,385,160; 2007/0108178; 2009/0266244; 8,091,472; 2008/0302778; 2009/0126580; 6,175,099; RE40,290; 2011/0114624; 8,247,745; 9,980,322; 10,841,981; 10,512,363; 10,852,002 — are reproduced exactly as retrieved.

Primary source of record: https://patents.google.com/patent/US10492641/en (claims and citation list). Individual reference content verified at the Google Patents, FreePatentsOnline, PatentImages, and USPTO/ISA search-report pages cited inline above.

I'll ground this obviousness analysis in the actual prior-art references cited on the patent's page. Let me verify the content of the most pertinent ones.

The Veltrop reference (US 2011/0283895 A1 / US 8,522,675) and the Duke reference (US 2004/0020915 A1 / US 7,105,779) are both highly relevant. Let me verify the remaining key limitations — the downwardly-depending lid-holding shelf, the pass-through openings, and the continuous undivided surface.

Obviousness Analysis — U.S. Patent No. 10,492,641 under 35 U.S.C. § 103

Scope note. This analysis builds on the prior summary/overview sections (bibliographic data, claim-1 plain-language map, litigation context) and does not repeat them. It uses the references appearing in the "Prior Art"/Citations section of the patent page (the 160–192-item citation list at https://patents.google.com/patent/[US10492641](/patent/US10492641)/en), keyed to their published application numbers so they can be located literally.

Legal frame. App. 15/985,255 was filed May 21, 2018, claiming priority to Apr. 19, 2016 — i.e., post-AIA, so § 103 is applied against AIA § 102(a)(1)/(a)(2) art. Each reference below published/granted well before Apr. 19, 2016 and is therefore available as prior art. The single independent claim is claim 1; claims 2–34 depend on it.

1. The prior-art references that matter (all from the patent's own citation list)

Commercial-art corroboration (non-patent, same field): the Merco MHC-22 spec sheet (©2007) advertises "Conduction heat — directly transfers heat from both top & bottom," "Independent upper and lower heating system," "Individual heat zone for each bin," "Digital display for each bin," and "pre-attached stainless steel covers." This is admissible as a printed publication/prior public use and shows the claimed functional result was already on the market.

Family caution (not prior art). A search also surfaced US 10,512,363 B2 ("Multi-zone food holding bin," app. 15/984,760, filed 2018-05-21, same inventors Kestner/Lyons/Hartfelder/McCoy, same assignee Prince Castle). It shares the '641 title and inventors and is a sibling application, not prior art — do not fold it into any § 103 combination. (It is also not listed in the family applications table reproduced on the '641 page, an inconsistency in the source record worth flagging.)

2. Element-by-element mapping of claim 1

Result: every limitation of claim 1 except the specific "downwardly depending lid holding shelf" mounting geometry and the "free of dividing walls / substantially unobstructed" negative limitations is disclosed, most of it expressly, by Veltrop '895, Duke '915, and RTL '886 — three references in the same field, in the same citation record, all predating the 2016 priority date.

3. Combinations that render claim 1 obvious, and the motivation to combine

Combination A (primary): Veltrop '895 + Duke '915 + Prince Castle '472 (or Merco '160)

• Veltrop '895 supplies nearly the whole cabinet: two stacked compartments, a shelf separating them, IR heating from above and below, four independently-controlled zones per compartment at different temperatures, an open front and open rear, and a bezel with four zone displays.
• Duke '915 supplies the dual-mode heating architecture the claim requires — a radiant heat source above the tray and a conductive (aluminum, resistively heated) surface below it — plus front/rear tray openings and independent per-compartment control.
• Prince Castle '472 / Merco '160 supply the lid/cover-holding structure retained within the compartment (for claims 21–25), which is the missing structural adaptation. The '641 specification itself frames the lid shelf as no more than an elevated support ("suspended above the continuous bottom surface… fixedly attaching a base of the shelf to a top surface of the food holding compartment"), confirming it is a mounting/placement expedient, not an inventive mechanism.

Motivation: All three are in the same art of QSR food-holding/warming cabinets, address the same problem (holding different pre-cooked foods at their own ideal temperatures for extended periods), and come largely from the same assignee/inventor group (Veltrop, Hartfelder, Chung, Maciejewski — all Prince Castle) already in the '641's own citation list. Where references share the same field and solve the same problem, KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398 (2007), holds the combination can be obvious as a matter of "ordinary creativity," especially where the art reflects "a finite number of identified, predictable solutions."

Combination B (alternative primary): Duke '915 + Veltrop '895 + PC '472

Duke '915 alone teaches independent compartment temperature control, radiant-top + conduction-bottom heating, the shelf-defined tiers, and front/rear tray openings — but only one heating zone per compartment. Veltrop '895 supplies the missing "two zones per compartment, each independently controlled." The motivation is the express teaching in Duke that "different food products require different amounts of IR energy to be held in optimum condition," combined with Veltrop's express teaching of four separately-controlled bays at different temperatures. Combining them is the predictable union of two known solutions to one known problem.

Combination C (alternative primary): RTL '886 (or its continuation US 6,607,766) + Veltrop '895 + PC '472

RTL '886 supplies the pass-through inlet/outlet door configuration, anodized-aluminum upper and lower heated surfaces, and per-compartment independent control — i.e., the "one heated surface above, one below, one continuous surface per tier" architecture. Its continuation US 6,607,766 even shows a shelf with heating elements on both sides (surfaces 102/104, housings 130/132), which is the '641's claim-30 "upper thermally conductive plate + lower thermally conductive plate" structure. Veltrop '895 adds the multi-zone-within-a-compartment independent control, and PC '472 adds the retained lid.

Why the negative limitations ("substantially unobstructed"; "free of any dividing walls," claims 19–20) do not save the claim

The '641 specification itself supplies the motivation: the continuous, divider-free surface "can be easily accomplished" for cleaning and is "much easier to clean than compartmentalized or divided heating chambers." That is a recognized, ordinary design trade-off (cleanability vs. thermal isolation). And the cited art confirms dividers were known to be optional: US 2009/0126580 A1 (Hartfelder, Prince Castle), in the '641 citation list, is directed to a removable divider for a food warming apparatus — teaching that the presence/absence of compartment dividers is a design choice a POSITA would freely make. Omitting a fixed divider where cleanability is desired is, at most, an obvious substitution of one known option for another.

Design-incentive / market-pressure motivation

The '641 background recites the exact problem the prior art set out to solve: known bins hold food "<15 or 20 minutes before the food item must be discarded." Duke '915, RTL '886, and Veltrop '895 each describe extending holding time / holding different foods at different temperatures. The claimed "extend the palatability time… by a factor of two or more" is thus the same result these references were already pursuing, giving a strong "reason to combine" under KSR.

4. Dependent claims — where the obviousness case is strongest and weakest

5. Counterarguments the patentee will raise (and how they fare)

1. "No single reference shows all four zones with both top and bottom independently controllable heating elements." True as to any one reference; the claim is nonetheless obvious over the combined teachings of Veltrop '895 (zones + top/bottom IR + independent control) and Duke '915 (top radiant + bottom conductive, independent per compartment). § 103 asks about the claimed subject matter as a whole, not about a single anticipatory reference.
2. "The cited references use dividers/separators; claim 1 requires unobstructed compartments." Undercut by the '641's own cleanability rationale and by PC '580 (removable dividers) in the same citation list.
3. "Secondary considerations (2× palatability extension)." The '641 asserts a "factor of two or more," but (i) Duke '915, RTL '886, and Veltrop '895 were all already directed to extended holding time, weakening any nexus, and (ii) the record does not show the result is unexpected relative to the closest prior art. Without evidence of unexpected results tied to a specific claimed element, this argument is weak on the present record.
4. "Common assignee / same-inventor references shouldn't be combinable." Common ownership is not a bar; if anything, the shared Prince Castle lineage (Veltrop, Hartfelder, Chung, Maciejewski) and the two Prince Castle references the '641 itself incorporates by reference (US 2011/0114624 A1; US 8,247,745) show the inventors treated this body of work as a single, combinable design space.

6. Bottom line

• Claim 1 is likely obvious over Veltrop '895 in view of Duke '915 (and/or RTL '886), further in view of Prince Castle '472 / Merco '160 for the lid-holding structure. The only limitations not squarely met are the "downwardly depending" mounting of the lid shelf and the divider-free/unobstructed negative limitations — both of which are addressed by the '641's own stated rationale (cleanability, elevated lid storage) combined with PC '580's teaching that dividers are optional.
• Claims 2–18 and 26–34 are very strong invalidity targets (largely Veltrop '895 + Duke '915 + the incorporated-by-reference Prince Castle control/temperature-sensor art).
• Claims 19–20 and the lid-shelf mounting in claim 1 are the two pressure points where a defendant would need the most developed motivation showing.

Litigation relevance (building on the earlier section, not repeating it): it is notable that the primary U.S. district-court defendant identified earlier — Duke Manufacturing Co. in Marmon Foodservice Technologies v. Duke Mfg., No. 4:25-cv-01491 (E.D. Mo.) — is the owner/prosecutor of US 2004/0020915 A1 / US 7,105,779 / US 7,227,102, which are cited on the face of the '641 patent and are central to the § 103 combinations above. Separately, the IPR2026-00406 petition identified earlier challenges the sibling patent US 10,852,002, not the '641 — so no PTAB challenge to the '641 has been confirmed.

7. Explicit uncertainties and flags

1. Date conflict (carried forward): the header states "Current Date: April 26, 2026," the session date is stated elsewhere as 2026-09-30, and the environment says 2026-09-30. I have reported source dates literally and not reconciled them.
2. Exact publication-to-grant mapping of the Duke family: the visible citation list includes US 2004/0020915 A1; the related grants US 7,105,779 and US 7,227,102 are in the same Duke family. I could not confirm from the retrieved page which specific application the '915 publication matured from, so I have cited the publication number as listed and the grants as family members rather than asserting a one-to-one correspondence.
3. "Downwardly depending" gap: I did not locate a cited reference that expressly mounts the lid-holding shelf so that it depends from the top panel / from the shelf (as opposed to wall-mounted racks/rods). I am flagging this as a genuine evidentiary gap rather than asserting the limitation is squarely disclosed.
4. Merco MHC-22 spec sheet is dated ©2007 and is offered as corroborating public-use/printed-publication evidence; I have not verified its public-availability date beyond the copyright notice shown.
5. No auto-correction applied. All identifiers (10,492,641; 10,852,002; 10,512,363; IPR2026-00406; 4:25-cv-01491; the cited publication numbers) are reproduced exactly as retrieved.

Primary source of record: https://patents.google.com/patent/US10492641/en (claims and citation list); reference content verified at the Google Patents / FreePatentsOnline / PatentImages pages cited inline above.