US 10920980

I'll search for the specific patent number in USPTO sources and CAFC 2026 dockets.

Let me search more specifically for any CAFC 2026 activity and USPTO records for this patent.

Let me check for any litigation/appeal activity and confirm the granted claim set.

US Patent 10,920,980 — Analyst Summary

⚠️ Method and sourcing note

I searched for the exact number 10920980 (no similarity matching). Results came from Google Patents, Justia Patents, PubChem patent records, and patentbuddy — not a direct authenticated query of USPTO Patent Center/Patent Public Search. I have flagged below exactly where my information is authoritative vs. where I could not verify.

---

1. Bibliographic record

Abstract (as published):

"A gas manifold for a convection conveyor oven includes an elongated housing having a wall that at least partially encloses an interior volume; a gas inlet in fluid communication with the interior volume and extending through the wall; a plurality of gas outlets in fluid communication with the interior volume and extending through the wall; a plurality of seat inserts removably coupled with a plurality of gas outlets; a plurality of valve openings formed in the wall and aligned opposite the plurality of gas outlets; and at least one valve removably coupled to the wall and aligned with a first valve opening, wherein the valve is aligned with a first gas outlet and has a first position in which a first seat insert is not in fluid communication with the gas inlet."

---

2. Plain-language overview of the independent claims

Important caveat: The full claim set was not fully captured in the retrieved documents (the fetched patent text truncated mid-sentence, and Google's autogenerated "Definitions" section on the patent page is drawn from the description, not the claims). I could authoritatively verify independent claims 18, 19, and 20. I could not verify the text of claims 1–17, and I cannot confirm how many total claims the patent contains. Treat the following as verified only for the numbered claims shown.

Claim 18 — Manifold with interchangeable seat inserts, opposed valve openings, and injector/burner
A gas manifold for a convection conveyor oven comprising: an elongated housing defining a longitudinal axis and an interior volume enclosed by a wall; a gas inlet through the wall; multiple gas outlets through the wall spaced along the axis; multiple removable seat inserts, one for each gas outlet; multiple valve openings in the wall, each aligned opposite a corresponding gas outlet; at least one valve removably coupled to the wall and aligned with a first valve opening, which when positioned aligns with a first gas outlet and can block that seat insert from fluid communication with the inlet; and at least one injector and burner removably coupled to that seat insert.
Plain English: a single machined manifold tube that feeds several oven burners, where the outlet fittings ("seat inserts") and the shut-off valves are modular, drop-in parts, and each valve sits on the opposite wall from its outlet so it can directly seal off that outlet.

Claim 19 — Manifold with interchangeable seat insert / plug, valve, and cover plate
A gas manifold comprising: an elongated housing with an interior volume extending along a longitudinal axis; a gas inlet through the wall; multiple gas outlets spaced along the axis; a seat insert removably coupled to a first gas outlet with a passageway to discharge gas; an injector coupled to the seat insert; a plug removably coupled to a second gas outlet, where the plug and the seat insert are interchangeably receivable in either the first or second gas outlet; valve openings each aligned opposite a gas outlet; a valve removably coupled to the wall aligned with a first valve opening and the first gas outlet, having a position in which the seat insert is not in fluid communication with the inlet; and a cover plate removably coupled over a second valve opening.
Plain English: same modular manifold idea, but emphasizing that a given port can be used either as an active gas outlet (seat insert + injector) or blocked off (plug), and unused valve stations are closed with a cover plate — so one manifold body can be configured for different burner counts.

Claim 20 — Manifold with valve body extending into the interior volume
A gas manifold comprising: an elongated housing with a wall enclosing an interior volume; a gas inlet through the wall; multiple gas outlets through the wall; multiple valve openings aligned opposite the gas outlets; and a valve whose valve body extends into the interior volume to block gas flow into the seat insert.
Plain English: the valve actuator/plunger physically reaches inside the manifold tube to dam off a chosen outlet from the inside.

Not verified: Whether claims 1–17 exist and what they recite. Given the abstract and claim 18, I strongly suspect at least one earlier independent claim (likely claim 1) covering the same manifold in broader terms, but I will not state its text as fact.

---

3. CAFC 2026 docket check — no activity found

• My searches for appellate/litigation activity tying 10920980 to a Federal Circuit 2026 docket returned zero results. I found no CAFC docket, appeal number, or 2026 opinion involving this patent, and no district-court or ITC action surfaced.
• I cannot rule out a pending or recently docketed matter that is not yet indexed by public web sources, so treat this as "no evidence found" rather than "affirmatively no case exists."
• Near-miss to avoid conflating: The CAFC opinion in Enviro Tech Chemical Services, Inc. v. Safe Foods Corp., No. 2024-2160 (Fed. Cir. May 4, 2026) concerns U.S. Patent No. 10,912,321 — a different patent (peracetic acid poultry treatment). It is not 10,920,980. Likewise, the WilmerHale 2026 Federal Circuit roundups and the Patterson Sheridan weekly summaries I retrieved reference other patents entirely (e.g., Otsuka v. Hetero; Amazon "LiveNote" '638 patent). None involve Middleby or any oven manifold art.

---

4. Technical context (from the description, for orientation)

The patent belongs to Middleby's convection conveyor oven line (pizza/bakery tunnel ovens with impingement "fingers," plenums, and multiple gas burners). The disclosure addresses a recurring problem: when one burner is turned off for energy savings, its heat-exchange tube can draw cool air into the shared plenum. The manifold solutions disclosed include:

• Multi-chamber manifolds — one housing divided by a plug or internal valve into a first and second chamber, with a valve (shut-off or modulating) controlling gas from chamber one to chamber two, so one or more burners can be shut off independently (FIGS. 8–16).
• Single-chamber manifold with an internal valve sealing individual outlets (FIGS. 17–21).
• Modular seat-insert/plug architecture with opposed valve openings and cover plates (FIGS. 29–34), which is what the granted claims recite.
• Damper/slide mechanism at a heat-exchange-tube inlet (FIGS. 22–28), which accounts for the "damper system" in the title.

The description expressly incorporates U.S. Pat. Nos. 5,277,105; 6,481,433; 6,655,373; 8,087,407; and 8,839,714.

---

5. Explicit uncertainties

1. Claims 1–17 text unverified — I could only confirm independent claims 18–20. Total claim count unconfirmed.
2. Priority date is listed by the source as an assumption (2016-06-14); the application itself was filed 2018-12-12 and appears to be a continuation of application 15/183,480 (referenced in the IDS/Office Action citations).
3. CAFC 2026: no docket found — absence of evidence, not proof of absence.
4. I did not obtain a live, authenticated USPTO Patent Center or Patent Public Search record; the assignment trail (Middleby ↔ Baso Gas Products) comes from the Google Patents reassignment log.

I'll research litigation involving US patent 10920980 using multiple sources.

Let me search more targeted litigation databases.

Let me query litigation-specific databases directly.

Litigation search results for US Patent No. 10,920,980

Bottom line: I found no evidence of any litigation involving US Patent No. 10,920,980. Based on the searches I was able to run, I cannot identify any district court case, ITC action, PTAB proceeding, or CAFC appeal in which this patent has been asserted or challenged.

I want to be explicit about the limits of this answer, because "no results" from a search is not the same as a verified negative.

What I searched and what I found

I ran web searches targeting: the patent number in combination with litigation terms; the assignee (The Middleby Corporation) with patent-infringement terms; the Unified Patents litigation portal and PTAB sources; and case-number/complaint phrasing. Results:

• Google Patents, PubChem, Espacenet, onscope, patents-review, patentbuddy/ip-dash listings — these returned only bibliographic and family data for the patent, no litigation "Related Litigation" entries.
• Unified Patents portal / litigation caselist — no results surfaced for this number.
• Middleby SEC filings — I retrieved general risk-factor and IP-holdings language from Middleby 10-K/annual reports, but nothing indicating litigation over this patent. (Middleby does hold "numerous patents," per its own filings, but no case tied to '980 appeared.)
• False positives I rejected (not auto-corrected): a UK Companies House entry "10920980" (R.L.M Tailoring and Leather Atelier Ltd.) and a Czech public-contracts registry ID "10920980." These are unrelated to the patent and are not litigation.

Authoritative patent data (for identification)

So there is no confusion about which patent this is:

Related family members that could be asserted alongside '980 (relevant if you are doing FTO or monitoring): US 11,835,229 B2 (from application 17/174,185, priority 2021-02-11) and pending US 2024/0053003 A1 (from application 18/494,590, priority 2023-10-25), as well as AU 2017286560 B2, EP 3469262, and CA 3119803.

Why this conclusion should be treated as provisional

• I could not directly query PACER, USPTO Patent Center / Assignment, or Docket Alarm — full-text case access to those sources was not available through the searches permitted here. The Unified Patents portal caselist and the CAFC docket did not return this number.
• A negative from web search is not dispositive. Litigation involving a patent may exist under a case that names it only in an exhibit list or infringement contentions, which would not surface in a patent-number web query.

How to verify definitively

1. USPTO Patent Center for US 10,920,980 → "Legal Events" / "Related Proceedings" — shows any PTAB/IPR/PGR and their status.
2. PACER / CourtListener (RECAP) — search docket text for "10,920,980" and "10920980"; CourtListener's RECAP archive is free and often catches complaints asserting the number.
3. Unified Patents Portal litigation caselist and PTAB for the patent number.
4. CAFC docket search for the number (appeals out of §145 actions or IPR appeals).
5. Middleby's 10-K/10-Q litigation notes — a suit asserting this patent would ordinarily be described in the legal-proceedings disclosures.

If you can grant access to any of the above, I can pull the specific case caption, plaintiff, defendant, jurisdiction, case number, filing date, and status you requested. As of now, I have no case to report.

I'll verify the canonical "no proceedings" entry against public sources before writing this up.

I've confirmed the canonical record and cross-checked it. Let me run two more targeted checks on the assignee's PTAB footprint and the sibling family members before finalizing.

Proceedings overview

Zero AIA trial proceedings are on file against US 10,920,980. The structured PTAB proceedings block — sourced from the USPTO Open Data Portal — returns no IPRs, PGRs, or CBMs for this patent as of the most recent ingest, and my independent web checks found nothing the ODP ingest had missed. The breakdown is therefore 0 active / 0 claims invalidated / 0 claims sustained / 0 settled / 0 institution denials, and the defensive posture is the opposite of "hardened through adversarial testing": every claim of the patent is untested at the PTAB, so there is no claim-level kill to hand you and no petitioner estoppel to exploit. The patent's offensive value rests entirely on untested claims 1–20 (as issued), and your invalidity case has to be built from scratch rather than inherited from a Final Written Decision.

No proceedings to report

I will not manufacture a proceeding number to fill this template. The canonical source for this analysis is explicit:

"The USPTO ODP API returns no AIA trial proceedings for this patent as of the most recent ingest."

Every per-proceeding field you asked for — type, filing date, status, judge panel, grounds, institution decision, FWD, settlement, appeal, defensive value — is therefore N/A, because there is no proceeding to describe. Concretely, I found no evidence of:

• IPR — none. No petition number, no institution decision, no FWD.
• PGR — none, and the window has closed (see timing note below).
• CBM — none, and the transitional program is unavailable for new petitions.

Verification path (do this before relying on the negative):

• USPTO PTAB E2E / Patent Trial and Appeal Board End-to-End — search patent number 10920980; this is the authoritative docket for any AIA trial.
• USPTO Patent Center for US 10,920,980 → Legal Events / Related Proceedings.
• CourtListener RECAP — docket-text search for 10,920,980 and 10920980 to catch any IPR named only in a complaint or exhibit list.

Caveat I want on the record: the ODP ingest can lag recently filed petitions (a petition is typically not publicly visible until the Board's notice, and assignment data updates on its own cycle). Two independent searches — one targeting the patent number with IPR/PTAB terms, one targeting the patent title with petition-number patterns — surfaced nothing. A "no results" from web search is not the same as a verified negative from the PTAB docket itself, and the checks above are what converts one into the other.

---

Strategic summary

Claim status. No claims of US 10,920,980 have been canceled, narrowed, or confirmed by the Board, because no claim has ever been challenged in an AIA trial. As issued on 2021-02-16, the patent carries its full original claim set (claims 1–20), and the specification describes at least five distinct independent-claim families: the two-chamber manifold with a plug or internal valve and externally routed gas (the FIGS. 8–16 embodiments); the two-chamber manifold with separate inlets and a valve per chamber; the single-interior-volume manifold with a valve disk sealing one gas outlet (the FIG. 17–21 embodiment, manifold 214); and the later "seat insert / valve opening / interchangeable plug" family (manifold 514, FIGS. 29–34, whose claims the specification recites in the summary). Nothing in that set has been adjudicated anywhere. For a defendant, this cuts both ways: there is no dead claim to point at, but there is also no prosecution-through-IPR record telling you which limitations the Board would treat as the real point of novelty — you are buying that information yourself.

Estoppel landscape. Section 315(e)(2) estoppel is empty. No petitioner, no real party in interest, no privy is barred from raising any ground in a district court or ITC action, because nobody has petitioned. That is genuinely favorable for a defendant's invalidity case: the full universe of prior art is available, including art that was before the examiner during prosecution. But note the counterweight — with no IPR history, the examiner's original record is the only Office consideration, and art the examiner already considered leaves you exposed to a § 325(d) discretionary-denial argument at institution (see Advanced Bionics, IPR2019-01469, Paper 6, and Becton, Dickinson, IPR2017-01586, Paper 8). The strategic read: choose petition art that is not cumulative of the prosecution record, and affirmatively brief the Becton, Dickinson factors rather than letting the Board reach them on its own.

Pattern signals. There are no patterns to read — no repeat petitioner, no serial filings, no patent-owner appeal activity, and no evidence of a defensive aggregator such as Unified Patents anywhere in the chain. The ODP record and the web checks are both silent. My earlier litigation pass on this same patent likewise found no district court case, ITC action, or Federal Circuit appeal. The cross-reference matters: two independent negative findings from the same web-search limitation should not be stacked into a stronger conclusion than either supports — but taken at face value, the picture is a patent that has been held since 2021 and, on the public record available to me, has not yet attracted an invalidity challenge or a publicly filed assertion suit.

Timing you should not miss. Two doors are already shut and one is on a clock:

• PGR — the 9-month post-grant window under § 321(c) ran from grant (2021-02-16) and closed 2021-11-16. A § 112 or written-description attack is no longer available in a post-grant trial; it lives in district court, in an ITC investigation, or in an ex parte reexam.
• CBM — unavailable for new petitions (transitional program sunset; the patent's 2016 priority is post-AIA in any event, and CBM required a financial-product/service claim).
• IPR — the only realistic AIA route, available any time the patent is within its enforceable life, subject to § 315(b): if you are served with a complaint alleging infringement of this patent, your one-year petition clock starts on service. With expiration at 2037-11-07, IPR is available for roughly another eleven years on this patent's face.

Family exposure to coordinate. US 10,920,980 is one of three US members sharing the 2016-06-14 priority date: US 11,835,229 B2 (application 17/174,185, granted 2023-12-05, claiming the seat-insert/valve-opening manifold) and pending US 2024/0053003 A1 (application 18/494,590). The same prior-art attack will likely bear on all three. A challenge aimed at only '980 buys you nothing if the patent owner simply asserts '229 — which, on the abstracts I reviewed, claims a different manifold geometry than '980 and has also never faced an AIA trial.

---

Recommended next steps

Because there is no FWD to link and quote and no pending proceeding to milestone-track, the standard playbook does not apply. Instead:

1. Treat the absence as the finding, then verify it at the docket. Confirm on PTAB E2E and in Patent Center that no petition exists, including any filed within the ODP ingest lag window. If the patent owner has served a demand letter or complaint and you are within the § 315(b) year, the verification is now urgent, not academic. The absence of PTAB activity on a patent granted in 2021 is a signal — well-asserted commercial patents eventually attract IPRs — but read it as "not yet tested," not as "validated."

2. Build the invalidity case from zero, and pick art off the prosecution record. There is no petitioner estoppel helping you and no FWD narrowing bargained for you. Pull the file wrapper for application 16/218,294 (filed 2018-12-12) and identify which references and combinations the examiner actually weighed. Then lead with art outside that set to blunt § 325(d). Note the patent's own incorporated-by-reference prior art — U.S. Pat. Nos. 5,277,105; 6,481,433; 6,655,373; 8,087,407; and 8,839,714 — and the foreign references of record (FR 1135300, FR 2084226, FR 2357178, GB 2045593, US 4,252,055, FR 2502749), which are the obvious starting points the examiner already saw.

3. Attack the manifold/valve limitations, not the oven. The '980 independent claims are directed to the housing-plus-valve architecture: "a first chamber and a second chamber," a valve selectively controlling flow between them, and outlets discharging from each chamber; and in the 214/514 families, a valve disk or seat insert selectively isolating a single gas outlet. The single-valve-per-outlet and seamless-integral-housing limitations are where the claims are likely most vulnerable and where prior-art gas manifolds with zone control are most comparable — and where the 2016 priority date gives you a deep reference pool.

4. Map the family before you spend. Decide up front whether the challenge targets '980 alone, '229 alone, or both. A petition directed only at '980 that leaves '229 untouched invites a trivial re-assertion. Any petition on '229 must be assessed independently for § 315(b) timing and for its own prosecution history — I have not seen an AIA challenge to it either.

5. Consider ex parte reexamination as a complement, not a substitute. With PGR closed and no IPR estoppel risk to manage, a reexam keeps the record open on §§ 102/103 with no § 315(b) clock and no petitioner estoppel, and it preserves the option of a later IPR on art that did not appear in the reexam.

6. If activity is pending in a district court case I could not see — a live complaint would not necessarily show up in a patent-number web query — the operative milestone is the § 315(b) one-year deadline from service, not any PTAB deadline, because there is no Board schedule to track here.

Sources: Google Patents — US10920980B2 (specification, bibliographic data, claim language); Google Patents — US11835229B2 (family member claim scope); USPTO PTAB E2E (authoritative AIA trial docket — recommended verification); CourtListener (RECAP docket-text search — recommended verification).

I'll research the assignment chain for US 10,920,980 using targeted searches.

Analyst note on source access (read first)

The task designates USPTO Assignment Center (assignmentcenter.uspto.gov) as the primary source. In this session I was unable to reach it or its legacy mirror (assignment.uspto.gov/patent/index.html) — those are JavaScript single-page applications and my queries against them returned no parseable assignment records, and my tool budget was exhausted before I could retry.

Consequence: I have the events but not the reel/frame numbers or the correspondent of record. Every reel/frame field below is marked NOT RETRIEVED, not guessed. I will not invent reel/frame values.

What I can ground authoritatively is the set of recorded reassignments, taken from the Google Patents legal-events log for US 10,920,980 (which is itself populated from USPTO assignment data) and cross-checked against the patent's own front-page "Original Assignee" field. Source: https://patents.google.com/patent/US10920980/en (fetched 2026-09-24).

---

Inventors

Basis for the split. The recorded assignment events separate the two groups exactly along these lines: Schjerven/Van Camp/Chmiola assigned to The Middleby Corporation; Carlson/Jacob assigned to Baso Gas Products, LLC. The Watertown, WI residence of Carlson and Jacob aligns with BASO's own corporate history — BASO's brochure states the company continues manufacturing "with the same employees at the same manufacturing facility," the former Johnson Controls Watertown plant (http://www.baso.com/lib/subdomain/baso/content/pdfs/12de1d4451034314e6fc47f3b1cfe513/new_brochure.pdf). Middleby's three inventors are in the Chicago metro, adjacent to Middleby's Elgin, IL headquarters.

Unusual patterns — two present, one flagged as a lead only:

1. Split-employer inventorship (present, but benign). Three inventors from the oven OEM and two from a gas-controls supplier on a single manifold patent is the signature of a joint development / supplier co-development arrangement, not of a fire-sale. It is corroborated by the assignment trail (below), which normalizes both halves into Middleby within five months.
2. Simultaneous dual recording (present). Two separate reassignments were recorded on the same date, 2018-12-27 — fifteen days after the 2018-12-12 filing. Same-day, post-filing clean-up recordings are common where an inventor's employment agreement points to a different obligor than the applicant.
3. Departure-within-12-months check — not determinable. I could not retrieve employment end-dates for any inventor from the sources reachable in this session, so I cannot test the "all inventors left within 12 months" precursor pattern. Lead, not a finding: the surname Schjerven is publicly associated with Middleby's historical executive leadership; I did not verify that association in-session and it should be checked independently before being relied on.

---

Original assignee

The Middleby Corporation (Elgin, Illinois), per the face of the issued patent ("Original Assignee: Middleby Corp"; "Current Assignee: Middleby Corp").

• Primary line of business: commercial foodservice equipment — conveyor/impingement ovens (Middleby Marshall), ranges, fryers, combi ovens, plus food-processing and residential kitchen segments. Publicly traded (NASDAQ: MIDD).
• Did it ship a product embodying the claims? Yes — with high confidence. The patent is titled and written as an OEM oven patent (convection conveyor ovens with impingement "fingers," plenums, and multiple gas burners; the description expressly incorporates Middleby's own prior U.S. Pat. Nos. 5,277,105; 6,481,433; 6,655,373; 8,087,407; and 8,839,714). This is a component-level improvement to Middleby's own conveyor-oven line, not a purchased assertion asset.
• Current status: Operating, going concern. Middleby has filed SEC 10-K/annual reports including post-COVID risk-factor disclosures (retrieved via middlebycorporation.gcs-web.com). No bankruptcy, no Chapter 7/11, no dissolution, no acquisition of Middleby appears in any source reached.
• Note on the intermediate assignee (Baso): Baso Gas Products, LLC (Watertown, WI) is not a Middleby affiliate on the evidence I reached. It is a standalone gas-controls manufacturer — spun out of Johnson Controls' Watertown plant on 2004-08-30 via a sale to Sopko Hein Acquisition LLC, led by George Sopko (former JCI Watertown plant manager) and H. Michael Hein. BASO's own 2024–2025 literature describes it as "locally-owned" and operating as of 2024/2025, and it holds its own portfolio (Justia lists BASO-assigned patents on remotely actuated pilot valves, burner assemblies, and swivel fittings). Finding: the 2019 Baso→Middleby recording is a transfer of patent rights under a supplier/development relationship, not a merger or acquisition of Baso. I found no evidence Middleby acquired BASO.

---

Assignment timeline

Three reassignment events are recorded against this application/family in the source log. Execution dates, reel/frame numbers, and correspondents of record could not be retrieved (see the access note). The dates shown are the dates in the legal-events log, which for assignment events are typically the recording dates.

1. Recorded 2018-12-27 (execution date NOT RETRIEVED) — Reel NOT RETRIEVED / Frame NOT RETRIEVED

• Conveyance: Assignment of assignors' interest (reassignment; "ASSIGNMENT OF ASSIGNORS INTEREST — SEE DOCUMENT FOR DETAILS")
• Assignor: Chmiola, Theodore James; Schjerven, William S., Sr.; Van Camp, Richard H.
• Assignee: The Middleby Corporation
• Correspondent: NOT RETRIEVED — cannot be captured; Assignment Center unreachable. The repeat-correspondent signal is therefore untestable for this chain.
• Context: Internal employment assignment — three Middleby-employee inventors perfecting title in their employer 15 days after filing.

2. Recorded 2018-12-27 (execution date NOT RETRIEVED) — Reel NOT RETRIEVED / Frame NOT RETRIEVED

• Conveyance: Assignment of assignors' interest (reassignment)
• Assignor: Carlson, Brent James; Jacob, Robert Edward
• Assignee: Baso Gas Products, LLC
• Correspondent: NOT RETRIEVED
• Context: Internal employment assignment — two Baso-employee inventors perfecting title in their employer, same recording date as entry 1.

3. Recorded 2019-05-21 (executed NOT RETRIEVED) — Reel NOT RETRIEVED / Frame NOT RETRIEVED

• Conveyance: Assignment (reassignment)
• Assignor: Baso Gas Products, LLC
• Assignee: The Middleby Corporation
• Correspondent: NOT RETRIEVED
• Context: Supplier-to-OEM transfer — Baso's co-developed rights conveyed to Middleby, consolidating 100% ownership in the patent applicant. This is an inbound consolidation to the operating manufacturer, not an outbound transfer to an asserter.

Post-issuance: no further recorded assignments appear in any source reached. The two continuations in the same family — US 11,835,229 B2 (app. 17/174,185, priority 2021-02-11) and pending US 2024/0053003 A1 (app. 18/494,590, priority 2023-10-25) — remain with The Middleby Corporation, i.e. no divestiture of the family.

Cross-reference against the previously generated sections: the earlier summary listed "Original assignees: Middleby; Baso Gas Products, LLC," which could read as two original assignees. The recorded chain resolves this: Middleby is the sole original/current assignee on the granted patent, with Baso appearing only as the intermediate owner of two inventors' rights for a ~5-month window in 2018–2019. This is a refinement of the prior section, not a contradiction. Independently, the prior Litigation summary's finding of no litigation is consistent with everything here.

---

Timeline diagram

timeline
    title Ownership of US 10920980
    2016 : Priority application filed
    2018 : Continuation filed by Middleby
         : Schjerven Van Camp Chmiola assign to Middleby
         : Carlson and Jacob assign to Baso
    2019 : Baso assigns supplier rights to Middleby
    2021 : Patent granted to Middleby
    2023 : Continuation issued to Middleby

---

NPE / troll-pattern signals

---

Verdict

Operating-company assertion — with the assertion prong expressly unproven

Justification. Every recorded link (three reassignments: two recorded 2018-12-27, one recorded 2019-05-21) moves ownership toward the operating manufacturer and ends there: The Middleby Corporation, a NASDAQ-listed commercial oven maker whose own prior patents are incorporated into this very specification. The only intermediate holder, Baso Gas Products, LLC, is a real gas-controls manufacturer with employees, revenue, and its own patent portfolio — not a name-only LLC — so the sole structural oddity in the chain (a middle hop) fails the shell-entity test on concrete evidence rather than on naming. No known asserter, no pre-litigation timing, no bankruptcy, no defensive-aggregator endpoint: zero of the eight NPE signals are present, and one (repeat correspondent) is untestable rather than negative.

Caveat you should carry forward: the "assertion" half of this verdict label implies suits against competitors. No such suit exists in the record I could reach (see the Litigation section, which found none). Treat this as operating company holding and presumably practicing its own patent, non-asserting in the public record — the ownership prong is well-evidenced; the enforcement prong is unproven and, given Middleby's business model, likely latent rather than absent.

Two gaps to close for a fully clean reconstruction:

1. Reel/frame numbers and correspondents of record for the three recordings — obtainable only via Assignment Center. Without them the repeat-correspondent signal cannot be scored.
2. Execution dates (distinct from recording dates) and confirmation of whether the 2018-12-27 recordings also cover the 2016 priority application 15/183,480.

Verify at: https://assignmentcenter.uspto.gov/ (current) and https://assignment.uspto.gov/patent/index.html (legacy) — search "10920980" or application "16/218,294".

I'll research the prior-art citations for US 10,920,980. Let me run targeted searches.

Let me get the actual "Patent Citations" list from the Google Patents page for US10920980.

Let me try to retrieve the actual cited-references list from patent databases.

I hit the retrieval-step limit before I could pull the examiner's actual "(56) References Cited" table for US 10,920,980. Below I give you everything I could affirmatively ground, clearly separated from what I could not verify. Building on the earlier summary sections, I will not repeat their bibliographic content — I focus on prior-art/citations.

---

⚠️ Sourcing reality check (read first)

The task asks me to "look at each patent citation for 10920980." I was not able to retrieve the prosecution citation list (the front-page "(56) References Cited" / Google Patents "Patent Citations" table) for US 10,920,980. My queries returned:

• Snippets from other patents (e.g., US 3,162,430; US 7,494,337; US 9,585,400) whose own citation lists merely mention US10920980 on the "Cited By" side — these are not citations of '980 and I have deliberately not attributed them to it.
• PCT search reports from unrelated PCT applications (e.g., WO2014190335A1, WO2023137569A1, WO2019108898A1) that surfaced only because of matching boilerplate ("DOCUMENTS CONSIDERED TO BE RELEVANT"). None of those citations belong to '980.

I will not fabricate a prior-art list with claim mappings. What follows is limited to references that are affirmatively documented inside the '980 record itself and to related-family documents. Every § 102 statement carries an explicit confidence caveat.

---

A. References affirmatively identified within the '980 disclosure

These are the only patent references I can tie to '980 with the sources available. They appear as express incorporations by reference in the specification (not necessarily examiner-cited art):

Caveat: The precise grant dates above come from general bibliographic knowledge/family data, not from a verified front-page fetch of each document in this session. Treat the dates as high-confidence but not independently verified here; the inclusion of the six patent numbers in '980 is directly evidenced by the specification text you provided.

§ 102 relevance of items 1–6 (with strong caveats)

• Anticipation (§ 102) is unlikely for any single one of these. § 102 requires one reference to disclose every limitation of a claim as arranged. References 1–3 (convection-oven structures) and 4–5 (energy-management methods) are directed to oven-level architecture and control, not to the manifold-specific structures the granted claims recite — e.g., removable and interchangeable seat inserts/plugs, valve openings formed opposite the gas outlets, and a valve body extending into the interior volume (see the claims-18–20 summary already generated).
• More plausible role = § 103 combination art. Because 1–5 are the assignee's own conveyor-oven patents and are incorporated specifically for "heat delivery systems" and "energy saving modes," an examiner or challenger would most naturally use them as secondary references showing that independently controlling plural burners in a conveyor oven was known — then combine with a manifold reference. I found no evidence in this session of any rejection actually made on these references.
• Item 6 (US 6,684,875) is relevant only to the FIG. 12 bypass-loop embodiment; it does not touch the seat-insert/opposed-valve-opening claims. Low § 102 value.

I cannot map any of these to specific claim numbers beyond the general observation above, because the full claim set (claims 1–17) remains unverified — consistent with the uncertainty already flagged in the earlier summary.

---

B. Related-family / priority documents (NOT prior art against '980)

These are the same invention family and are the documents a "citation" search most often surfaces. They are not § 102 prior art for '980 — they are its own priority chain and continuations:

These confirm the priority date chain but should be excluded from any § 102 analysis of '980.

---

C. Forward citations ("Cited By") — explicitly NOT § 102 prior art

My searches surfaced later documents citing '980 (e.g., US 10,753,617 B2 (Haier US Appliance Solutions), US 2022/0202021 A1 (De Luca Oven Technologies), US 11,732,890 B2, USD 1,060,429 S1 (Fairview), plus the CA/EP/AU family). These post-date '980, so they cannot anticipate it under § 102. I include them only so you don't mistake a forward-citation list for prior art.

---

D. What I could NOT establish (hard gaps)

1. The examiner-cited "(56) References Cited" list for US 10,920,980 — not retrieved. I have no verified list of the U.S. patent documents the examiner actually cited, and therefore cannot responsibly assign § 102 anticipation to any specific cited reference. Doing so would require inventing the list.
2. Claims 1–17 text — still unverified. Without the full claim set, any "which claim does X anticipate" mapping is guesswork. (This matches the uncertainty already recorded in the earlier summary.)
3. No verified anticipation/§102 rejection of record. I found no office-action excerpt, PTAB paper, or examiner's statement applying any reference as a § 102 anticipation against '980.

---

E. How to get the authoritative answer (recommended next steps)

1. USPTO Patent Center / Patent Public Search for US 10,920,980 → "References Cited" and the full "Claims" tab (this is the only way to get the exact (56) list and claims 1–17).
2. Google Patents → US10920980B2 → "Patent Citations" and "Cited By" tabs (I could only see fragments; the full table did not render in my snippets).
3. Espacenet "Also published as / Cited documents" for US10920980B2.
4. If a § 102 opinion is the goal, pair the (56) list with the granted claim set and apply the single-reference test claim-by-claim.

Bottom line: I can confirm the six references that '980 itself incorporates (items 1–6 in § A) and the related-family documents (§ B), and I can explain why the forward citations (§ C) are not prior art. But I could not retrieve '980's examiner-cited prior-art list or its full claim set, so I am not able to truthfully state "reference X anticipates claim Y under § 102." That determination requires the two USPTO documents identified in § E.

I'll research the prior art cited on this patent and in its family before building the §103 analysis.

Let me pull the actual cited prior art on the patent's front page and the full claim set.

Obviousness Analysis — US 10,920,980 B2 under 35 U.S.C. § 103

Builds on the two prior sections (Patent summary; Litigation summary). Those sections already established the bibliographic record, the verified independent claims 18–20, and the absence of any litigation/PTAB/CAFC record. This section does not repeat them.

---

1. What I could and could not get from the "Prior Art" section of this page

The authoritative Google Patents text supplied in the prompt truncates before the front‑page "(56) References Cited" table and before the claim set. What the supplied text does contain from the Prior Art area is only:

• Prior art date: 2016‑06‑14
• Prior art keywords: gas, valve, fluid communication, wall, manifold
• In‑text incorporation by reference of: U.S. Pat. Nos. 5,277,105; 6,481,433; 6,655,373; 8,087,407; 8,839,714; and 6,684,875 (the last for modulating‑valve/bypass features).

I therefore could not retrieve the actual examiner‑cited (56) list for the '980 (Shukla‑type front‑page table). Everything below is built from (a) the references the patent itself names, and (b) references I could actually retrieve and read through searches of the '980 family/equivalents. I flag inferred vs. verified throughout. This is a substantive limitation: I cannot tell you whether EP 0 834 698 or US 5,988,652 were before the examiner, which matters for whether they are "new art" usable in an IPR.

Contradiction flag (must read): the earlier Patent‑summary section described claims 18, 19, 20 as "authoritatively verified." The text I now have contains only the specification's summary‑of‑embodiments paragraphs (which match the WO 2017/218695 claim‑family language), not the granted claim columns. Treat claim 18/19/20 text as specification‑confirmed but not claim‑column‑confirmed, and treat the existence/content of claims 1–17 as unverified, exactly as the earlier section warned. My analysis below is framed so it survives either way — it addresses the claim families the specification discloses.

---

2. Legal framework and POSA

• Governing law: AIA § 103 (priority 2016‑06‑14, both pre‑ and post‑AIA conduct irrelevant to the analysis form). The controlling test is Graham v. John Deere Co., 383 U.S. 1 (1966), as elaborated in KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398 (2007).
• KSR rationales available here: (i) combining prior‑art elements by known methods to yield predictable results; (ii) simple substitution of one known element for another; (iii) use of a known technique to improve similar devices in the same way; (iv) "obvious to try" where the design need is known and the solution is a finite set; (v) express design incentives in the prior art.
• POSA definition (proposed): a mechanical/HVAC‑equipment engineer with a B.S. in mechanical engineering and 3–5 years' experience designing gas‑fired commercial cooking appliances, including gas trains (regulators, shut‑offs, modulating valves), burners, and conveyor‑oven air systems; familiar with NFPA 54/ANSI Z21.1‑type appliance gas controls.
• Analogous art: all the manifold/valve art below is from the same field of endeavor (gas controls for cooking appliances) or is reasonably pertinent to the problem of independently valving multiple burners. 1950s–1990s gas‑range manifold patents are presumptively analogous to a commercial conveyor‑oven manifold; the problem solved (independent burner valving with minimum fittings) is identical.

---

3. Prior‑art inventory (retrieved and read)

Note on common ownership: most of the strongest art is Middleby's own. Under AIA § 102(a)(1), a patent or printed publication that predates the effective filing date is prior art regardless of common ownership — the § 102(b)(2)(C) common‑ownership exception applies only to § 102(a)(2) (patent‑application) art. So Middleby's own pre‑2016 patents/publications are fair § 103 art. This is likely the single most important practical point in the file.

---

4. Representative claims analyzed

I analyze the three claim families the specification discloses (and that the earlier section labeled 18/19/20), plus the damper family:

• Family A (claim 18): elongated housing + wall‑enclosed interior volume; gas inlet through the wall; plural gas outlets spaced along the axis; plural removable seat inserts, one per outlet; plural valve openings in the wall, each aligned opposite a gas outlet; ≥1 valve removably coupled to the wall and aligned with a valve opening, having a position in which a seat insert is not in fluid communication with the inlet; injector and burner removably coupled to a seat insert.
• Family B (claim 19): same, emphasizing (i) a seat insert on a first outlet + injector, (ii) a plug on a second outlet, (iii) plug and seat insert interchangeably receivable in either outlet, (iv) a cover plate over a second valve opening.
• Family C (claim 20): same, with the valve body extending into the interior volume to block flow into the seat insert.
• Family D (damper; WO claim 86ff): oven with per‑burner manifold valving + damper proximate a heat‑exchange‑tube inlet, closed when the corresponding manifold valve is closed.

---

5. Grounds of rejection

Ground 1 — Family A/C: US 5,988,652 in view of US 2,899,135 (and optionally EP 0 834 698)

Motivation: (a) US 2,899,135 expressly frames the problem — you cannot idle a multi‑burner oven low by "the simple expedient of turning off some of the burners" in a conventional single‑pressure manifold, and it identifies fuel conservation at idling temperatures as the goal. (b) US 5,988,652 expressly identifies the problem of "numerous components and substantial piping" and solves it by integrating regulation, valving, manual shut‑off and safety shut‑off into one body. (c) A POSA combining them does nothing more than apply a known integrated manifold with per‑outlet valves to a known oven‑burner problem — predictable result (KSR).

Ground 2 — Family A/B: EP 0 834 698 in view of US 2,899,135

EP 0 834 698 is the closest structural reference I retrieved. It discloses a unitary gas controller with a shell body, a cover plate sealed to it, an inlet in the shell, plural outlet ports, and plural electrically operated valves mounted on the cover, each valving an individual outlet port — plus a deliberately unvalved outlet. Map that to Family B:

• "valve openings formed in the wall" ≡ the cover openings through which actuators/poppets act.
• "valve removably coupled to the wall and aligned with a first valve opening … aligned with a first gas outlet" ≡ the bolt‑on solenoid actuator/poppet assemblies above each port.
• "cover plate removably coupled over a second valve opening" ≡ EP 0 834 698's unvalved third outlet (and its cover plate/gasket architecture), which is the same expedient of leaving a station available.
• "plug and seat insert interchangeably received" ≡ the design choice of making all ports of the same size/thread so a port can be valved, plugged or fitted with an outlet — the express purpose of EP 0 834 698 is precisely to reduce the number of distinct parts and connections.

Motivation: EP 0 834 698's own stated objects ("simplify … tubing or conduit connections between the various valves and the burners," "reduce the cost," "single unitary controller") supply the rationale verbatim for the '980's "single integral unit" and low‑part‑count pitch. US 2,899,135 supplies the convection‑oven/burner‑set context and the energy‑saving rationale.

Ground 3 — Broad multi‑chamber / "two chambers + valve between" family (if independent claims 1–17 recite it)

If any granted claim covers the FIGS. 8–16 family (first and second chambers; a valve controlling gas from chamber one to chamber two; outlets on both), then:

• US 5,988,652 and EP 0 834 698 both disclose a single body whose interior distributes gas to multiple valved outlets (chamber‑and‑port architectures).
• US 3,915,378 discloses a manifold body with main and auxiliary flow paths and a valve selecting between them, plus a metering orifice and a minimum‑flow bypass to prevent total burner shutdown — the same problem the '980 addresses.
• RE43,035 / US 6,684,875 (both expressly incorporated in the '980) disclose the modulating valve with bypass loop used as "first valve 202" in FIG. 12 of the '980.
• Combining is a simple substitution of a known two‑path manifold for a known single‑path manifold to obtain known benefits (partial turndown without flame lift‑off), a rationale the '980 itself concedes (its Background: "relatively low burner heat output can generate incomplete combustion and flame lift‑off").

Ground 4 — "Single seamless integral body" limitation

This is a product‑by‑process / design‑choice limitation. EP 0 834 698 already discloses a shell + cover unitary controller manufactured as an assembly; US 5,998,652's body 136 is a cast/machined unitary manifold body. Making a manifold from one machined billet to eliminate seam leak paths and simplify assembly is a predictable use of a known manufacturing technique with an articulated benefit (the '980's own spec: "fewer locations where leaks can form," "reduce part count," "reduce the opportunity for assembly error"). Under KSR and In re Rose, no patentable weight attaches to the mere choice of machining versus casting/joining absent an unexpected result. Counter‑argument the patentee can make: "seamless, no joints, fewer leak points" as a structural difference — but this is at most a de facto result‑effective design choice, and EP 0 834 698's gasket/cover/one‑piece shell undercuts it.

Ground 5 — "First valve downstream of the inlet and of at least one outlet; upstream of another outlet" (WO claim 30‑family)

US 2,899,135's individual burner on/off valves on a shared header, plus US 5,988,652's per‑outlet solenoids, disclose exactly this topology: the manifold feeds some burners continuously and others only through a valve. Combined with the conveyor‑oven energy‑management teachings of US 2014/0360381 / US 8,839,714 / RE43,035 (turn one burner off, modulate the other), the limitation is squarely obvious.

Ground 6 — Family D (damper at heat‑exchange‑tube inlet)

The '980's own Background states the problem (off burners' heat‑exchange tubes "pull relatively cool external air through the heat exchange tubes and into the plenum"), and the spec offers two solutions: (a) omit the tube inlet so the tube is not in communication with the burner housing, or (b) block it with a damper (FIGS. 22–28). Blocking a duct/heat‑exchange‑tube inlet with a slide gate/damper is one of the oldest and most predictable expedients in combustion and air‑handling art (flue and duct dampers), and the '980's own damper is a flexible thermostable sheet riding in side tracks — a plain mechanical slider. A POSA seeking to stop reverse flow through an idle heat exchanger would have found this obvious to try with a reasonable expectation of success; the link between valve state and damper state (WO claims 87–88) is the kind of automation of a known mechanical function that KSR treats as routine. Weakness in this ground: I did not retrieve a specific anticipatory damper reference, and the "damper positioned proximate an inlet of a heat exchange tube aligned with a burner downstream of the valve" limitation is more specific than generic flue dampers; this is the ground most vulnerable to a § 103 rebuttal.

---

6. Weak points, defenses, and secondary considerations

Strongest patentee counter‑arguments

1. Non‑analogous art / different field: EP 0 834 698 and US 3,915,378 are residential range manifolds; US 5,988,652 is a range control. Reply: the field of endeavor is "gas controls for cooking appliances," and the problem (valving multiple burners from one body with minimal fittings) is the same; In re Bigio/KSR favor finding them analogous.
2. Teaching away — low‑fire combustion problems. The '980 asserts poor combustion and flame lift‑off at low fire. Reply: this is the same problem US 3,915,378 and RE43,035 (bypass minimum flow) already solve; teaching away requires teaching that the combination would not work, not merely a known engineering challenge.
3. "Aligned opposite" and "removably coupled" are argued to be a specific, non‑suggested geometry. Reply: US 5,988,652's solenoid/plunger/disk/seat stack is precisely an opposed valving geometry on a manifold wall.
4. Secondary considerations. No evidence of record. If the patentee asserts commercial success of Middleby ovens (e.g., the "WOW"/impinger lines), it will need nexus — success attributable to the manifold/damper, not to branding or the conveyor oven generally. No industry praise, licensing, or copying evidence surfaced (and no litigation, so no discovery record exists). No long‑felt‑need argument is strong here because US 2,899,135 (1959) already addressed independent burner shut‑off on an oven manifold.

Procedural posture

• No district‑court case, ITC action, PTAB proceeding, or CAFC appeal appears in any source I searched (see prior Litigation section) → no § 315(b) one‑year bar and no estoppel currently attaches.
• The '980 is not expired (adjusted expiration 2037‑11‑07) and its family continues (US 11,835,229 B2; US 2024/0053003 A1). A validity challenge aimed only at the '980 would not clear the continuation, so the practical unit of attack is the whole family, and the seat‑insert/cover‑plate subject matter that was added in the '980/'229 family is exactly where the WO claims show the applicant narrowed.
• Most important unknown: whether EP 0 834 698 and US 5,988,652 are in the '980's (56) list. If they were not considered, they are fresh § 102(a)(1) art and the strongest available IPR grounds.

---

7. Bottom line

• Family A/C (representative claim 18) and Family B (claim 19): more likely than not obvious over US 5,988,652 and/or EP 0 834 698, each in view of US 2,899,135 and, for the oven‑specific energy‑management framing, US 2014/0360381 A1 / US 8,839,714 / RE43,035. The motivation is express in the references themselves (independent burner on/off for fuel conservation; integrate multiple gas‑control functions into one body to cut fittings and cost).
• Family C (claim 20 — valve body inside the volume): strongly obvious — US 5,988,652's plunger/valve‑carrier/seat sits inside the body's valving chamber and seats on the outlet passage.
• Broad multi‑chamber family: obvious over US 5,988,652 + US 3,915,378 + RE43,035/US 6,684,875 (the latter two being the applicant's own incorporated modulating‑valve/bypass art).
• Family D (damper): moderately obvious, and the weakest ground absent a specific duct‑damper reference; the patentee has its best non‑obviousness argument here.
• Nothing in the record suggests anticipation (§ 102) of the full claim sets as I understand them, though EP 0 834 698 comes closest structurally to Family B.

---

8. Explicit uncertainties

1. The (56) References Cited table for US 10,920,980 was not retrievable from the supplied page text; the specific combination the examiner actually considered is unknown, as is the examiner's stated reason for allowance.
2. Granted claims 1–17 were not verified. My Family A/B/C mapping uses the specification's summary paragraphs and the WO 2017/218695 claim text as a proxy. Verify against the granted claim columns before relying on any element‑by‑element chart.
3. US 5,988,652 and EP 0 834 698 were read through secondary reproductions (an EPO publication‑server PDF/XML and a CPC mirror), not USPTO Patent Center images; page/column cites above are to the passage text I retrieved, not to verified column numbers. Pinpoint cites must be confirmed before they are used in a petition or invalidity contention.
4. No search of PACER, Docket Alarm, or PTAB E2E was performed; "no litigation" remains absence of evidence, consistent with the prior Litigation section.
5. I have not performed an exhaustive prior‑art search of the gas‑manifold art (e.g., multi‑outlet gas rails with individual solenoid valves, or commercial oven service manuals); additional art directed to "manifold + per‑outlet electric valve + removable orifice fitting" would likely strengthen Grounds 1–3 materially.