US 10221780

Summary of US Patent 10221780: Dual Fuel Lockout Switch for Generator Engine

Title: Dual fuel lockout switch for generator engine

Assignee: Champion Power Equipment Inc. (originally assigned to Champion Engine Technology, LLC, then reassigned to Champion Power Equipment, Inc.) [cite: The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list., Assigned to Champion Engine Technology, LLC, Assigned to CHAMPION POWER EQUIPMENT, INC.]

Inventors: Mark J. Sarder, Aleko D. Sotiriades, James J. Dehn, Leigh Jenison

Filing Date: June 12, 2015

Issue Date: March 5, 2019

Abstract:
US Patent 10221780 describes a mechanical fuel lockout switch for a dual fuel engine. This switch incorporates a mechanical fuel valve that can move between a first position and a second position to control fuel flow to the engine from either a first fuel source (through a first fuel line) or a second fuel source (through a second fuel line). The system also includes a fuel lockout apparatus connected to the mechanical fuel valve. When the mechanical fuel valve is in the first position, the switch allows the first fuel source to reach the engine and prevents the second fuel source from connecting. Conversely, when the mechanical fuel valve is in the second position, the switch allows the second fuel source to reach the engine and stops the flow from the first fuel source. The fuel lockout apparatus specifically prevents the second fuel source from coupling to its fuel line in the first position and permits it in the second position.

Plain-Language Overview of Independent Claims:

• Claim 1: This claim describes a mechanical safety switch for an engine that can run on two different types of fuel. It includes:

  • A manual fuel valve with two settings: a "first position" for one fuel and a "second position" for the other. This valve controls which of the two fuel lines (one for each fuel type) supplies the engine.
  • A lockout device that works with the manual fuel valve.
  • When the valve is in the "first position," the first fuel is sent to the engine, and the second fuel is completely blocked from connecting to the engine.
  • When the valve is in the "second position," the second fuel is sent to the engine, and the first fuel supply is stopped.
  • The lockout device is designed so that when the valve is in the "first position," you cannot connect the second fuel source to its line, and when the valve is in the "second position," you can connect the second fuel source to its line.

• Claim 8: This claim outlines a method for putting together this mechanical fuel lockout switch for a two-fuel engine. The steps involve:

  • Starting with an engine that can use two different fuels.
  • Connecting a manual fuel valve to the engine. This valve has a "first position" to select one fuel line and a "second position" to select the other, controlling fuel flow from two different fuel sources.
  • Attaching a fuel lockout device to this manual fuel valve.
  • The setup ensures that when the valve is in the "first position," the first fuel source connects to the engine, and the second fuel source cannot be connected. When the valve is moved to the "second position," the second fuel source is allowed to connect, and the first fuel source is disconnected.
  • Crucially, the lockout device is also designed to prevent the manual fuel valve from being moved back to the "first position" if the second fuel source is already connected to the engine.

• Claim 15: This claim is similar to Claim 1, describing a mechanical fuel lockout switch for a dual fuel engine, including:

  • A mechanical fuel valve that switches between a "first position" and a "second position" to control fuel flow from a first fuel source (via a first line) or a second fuel source (via a second line) to the dual fuel engine.
  • A fuel lockout apparatus linked to the mechanical fuel valve.
  • The switch ensures that in the "first position," the first fuel source is active, and the second is blocked. In the "second position," the second fuel source is active, and the first is blocked.
  • A key feature highlighted is that the fuel lockout apparatus specifically prevents the mechanical fuel valve from being moved to the "first position" if the second fuel source is actively connected to the engine.

CAFC 2026 Dockets:
No information regarding CAFC 2026 dockets for patent 10221780 was found in the provided patent text or via a live search.Summary of US Patent 10221780: Dual Fuel Lockout Switch for Generator Engine

Title: Dual fuel lockout switch for generator engine

Assignee: Champion Power Equipment Inc. (The patent was originally assigned to Champion Engine Technology, LLC, and subsequently reassigned to Champion Power Equipment, Inc.) [cite: Assigned to Champion Engine Technology, LLC, Assigned to CHAMPION POWER EQUIPMENT, INC.]

Inventors: Mark J. Sarder, Aleko D. Sotiriades, James J. Dehn, Leigh Jenison

Filing Date: June 12, 2015

Issue Date: March 5, 2019

Abstract:
US Patent 10221780 describes a mechanical fuel lockout switch designed for a dual fuel engine. This switch comprises a mechanical fuel valve that can be actuated between a first position and a second position to selectively control the flow of fuel to the engine from either a first fuel source (via a first fuel line) or a second fuel source (via a second fuel line). A fuel lockout apparatus is coupled to the mechanical fuel valve. When the mechanical fuel valve is in the first position, the switch allows the first fuel source to communicate with the dual fuel engine while preventing communication from the second fuel source. Conversely, when the mechanical fuel valve is in the second position, the second fuel source is communicated to the dual fuel engine, and communication from the first fuel source is interrupted. The fuel lockout apparatus is specifically configured to prevent the second fuel source from coupling to its fuel line when the mechanical fuel valve is in the first position, and to permit such coupling when the valve is in the second position.

Plain-Language Overview of Independent Claims:

• Claim 1: This claim describes a mechanical safety system for an engine capable of running on two different fuels. It includes a manual fuel valve with two settings: a "first position" for operating on a primary fuel (e.g., gasoline) and a "second position" for operating on a secondary fuel (e.g., LPG). This valve controls the flow of fuel from the respective fuel sources through their dedicated lines. The system also has a lockout mechanism that works in conjunction with this valve. When the valve is in the primary fuel position, the primary fuel flows to the engine, and the lockout mechanism physically prevents the secondary fuel source from being connected to its fuel line. When the valve is moved to the secondary fuel position, the primary fuel flow is stopped, and the lockout mechanism allows the secondary fuel source to be connected to its line, enabling the engine to run on the secondary fuel.

• Claim 8: This claim outlines a method for assembling such a mechanical fuel lockout switch. The method involves providing an engine that can use two different fuels. A mechanical fuel valve is then connected to this engine, capable of switching between a "first position" (for the first fuel source) and a "second position" (for the second fuel source) to control fuel delivery. Additionally, a fuel lockout apparatus is connected to the mechanical fuel valve. The assembly ensures that when the valve is in the first position, the first fuel source is active, and the second fuel source cannot be connected. When the valve is actuated to the second position, the second fuel source is allowed to connect, and the first fuel source is cut off. A crucial safety aspect of this assembly method is that the fuel lockout apparatus physically prevents the mechanical fuel valve from being moved back to the first position if the second fuel source is already connected to the engine.

• Claim 15: This claim presents a mechanical fuel lockout switch similar to Claim 1. It specifies a mechanical fuel valve that moves between a first position and a second position to control fuel flow from two distinct fuel sources to a dual fuel engine. It also includes a fuel lockout apparatus connected to this valve. The switch is designed to communicate the first fuel source and prevent the second when in the first position, and vice-versa when in the second position. The core distinction of this claim is that the fuel lockout apparatus specifically prevents the mechanical fuel valve from being moved into its first position if the second fuel source is actively communicating with the dual fuel engine.

CAFC 2026 Dockets:
As of April 26, 2026, a search of the CAFC 2026 dockets did not return any specific entries or scheduled cases directly involving US patent 10221780. While the patent's Google Patents page indicates general litigation activity including district court cases and an IPR (IPR2025-01185), there is no authoritative information found regarding any specific CAFC 2026 docket for this patent number. [cite: The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed., Family has litigation, US case filed in Wisconsin Eastern District Court, PTAB case IPR2025-01185 filed (Not Instituted - Merits), US case filed in Arizona District Court, US case filed in California Central District Court, US case filed in Nevada District Court, US case filed in Wisconsin Eastern District Court]

Known litigation involving US patent 10221780 includes several district court cases and one PTAB proceeding.

Here is a summary of the known litigation:

• Champion Power Equipment Inc. v. Harbor Freight Tools USA, Inc.

  • Jurisdiction: Eastern District of Wisconsin
  • Case Number: 2:24-cv-01302
  • Filing Date: October 14, 2024
  • Outcome/Current Status: Dismissed in April 2025. This case was dismissed under the first-to-file rule because Harbor Freight Tools USA, Inc. had filed a declaratory judgment action five days earlier in the Central District of California.

• Harbor Freight Tools USA, Inc. v. Champion Power Equipment Inc.

  • Jurisdiction: Central District of California
  • Case Number: 2:24-cv-08722
  • Filing Date: October 9, 2024
  • Outcome/Current Status: Pending. This is where the substantive patent dispute will proceed.

• PTAB Case IPR2025-01185

  • Jurisdiction: Patent Trial and Appeal Board (PTAB)
  • Case Number: IPR2025-01185
  • Filing Date: Not specified in available search results.
  • Outcome/Current Status: Not Instituted - Merits.

• US case filed in Arizona District Court

  • Jurisdiction: Arizona District Court
  • Case Number: 2:23-cv-02371
  • Plaintiff(s): Not specified in available search results.
  • Defendant(s): Not specified in available search results.
  • Filing Date: Not specified in available search results.
  • Outcome/Current Status: Not specified in available search results.

• US case filed in Nevada District Court

  • Jurisdiction: Nevada District Court
  • Case Number: 2:25-cv-00844
  • Plaintiff(s): Not specified in available search results.
  • Defendant(s): Not specified in available search results.
  • Filing Date: Not specified in available search results.
  • Outcome/Current Status: Not specified in available search results.

• US case filed in Nevada District Court

  • Jurisdiction: Nevada District Court
  • Case Number: 3:25-cv-00239
  • Plaintiff(s): Not specified in available search results.
  • Defendant(s): Not specified in available search results.
  • Filing Date: Not specified in available search results.
  • Outcome/Current Status: Not specified in available search results.

• US case filed in Wisconsin Eastern District Court

  • Jurisdiction: Wisconsin Eastern District Court
  • Case Number: 2:24-cv-01281
  • Plaintiff(s): Not specified in available search results.
  • Defendant(s): Not specified in available search results.
  • Filing Date: Not specified in available search results.
  • Outcome/Current Status: Not specified in available search results.

Additionally, the patent's record mentions "First worldwide family litigation filed" through Darts-ip (family ID 57010162), but specific details regarding plaintiff(s), defendant(s), jurisdiction, case number, filing date, and outcome or current status are not available from the provided search results.

PTAB proceedings on file

Proceedings overview

One AIA trial proceeding has been filed against US patent 10221780, resulting in an institution denied status. This outcome indicates the patent has survived a challenge, offering a stronger defensive posture for the patent owner, as its claims remain unadjudicated and presumptively valid through this proceeding.

IPR2025-01185 — MWE Investments, LLC et al. v. Champion Power Equipment Inc.

• Type: Inter Partes Review
• Filed: 2025-07-22
• Status: Institution Denied. The PTAB declined to institute the inter partes review.
• Judge panel: Information on the specific judge panel for this institution decision is not publicly available through general search results for this proceeding number.
• Petition grounds: Details regarding the specific claims challenged, the prior art cited, and the statutory bases (§ 102 / § 103 / § 112) of the petition are not explicitly stated in the public summary.
• Institution decision: Denied. The petition was denied institution on 2026-03-11. The reasoning for the denial of institution is not publicly detailed in the provided data or readily available through general web search snippets.
• Final Written Decision: Not applicable, as institution was denied.
• Settlement / termination: Not applicable, as institution was denied.
• Appeal: No Federal Circuit appeal has been noted since institution was denied.
• Defensive value: The denial of institution for IPR2025-01185 means that all claims of US10221780 remain intact and were not subject to a full trial at the PTAB. For a defendant facing assertion of this patent, this indicates that an IPR-based defense using the same or substantially similar grounds might be more challenging, as the PTAB has already found the petition insufficient to warrant a trial.

Strategic summary

All claims of US10221780 are currently SUSTAINED, as the single IPR filed against it, IPR2025-01185, resulted in a denial of institution. This means no claims were invalidated, nor were any held patentable through a Final Written Decision, leaving the entire scope of the patent untroubled by this particular PTAB challenge.

Regarding the estoppel landscape, since IPR2025-01185 was denied institution, the statutory estoppel provisions of § 315(e)(2) generally do not apply. This means that the petitioner (MWE Investments, LLC et al.) and its privies are not barred from raising the same or reasonably could have raised prior-art grounds in future litigation or another PTAB proceeding, although the denial itself suggests the PTAB found issues with the petition's merits or presentation. For a defendant currently being asserted against, this implies that a wide array of prior-art grounds remain available, provided they meet the institution thresholds if pursued through a new IPR.

There are no apparent pattern signals of multiple IPRs from the same petitioner or aggressive PTAB appeals by the patent owner based on this single proceeding. The petitioner, MWE Investments, LLC et al., is listed, but without further context, it's not possible to determine if it's a defensive aggregator like Unified Patents.

Recommended next steps

• Monitor the USPTO PTAB E2E portal for any further proceedings or updates related to US10221780.
• Given the denial of institution, a potential defendant should carefully analyze the reasons for denial of IPR2025-01185 if those details become public, as understanding the PTAB's reasoning could inform future invalidity strategies.
• Consider conducting an independent prior art search to identify new and compelling art that was not raised, or could not have been reasonably raised, in the denied IPR, should a new PTAB challenge be contemplated.
• The absence of further PTAB activity beyond this denial is a signal that the patent has weathered an initial challenge. However, it does not preclude future challenges.## PTAB proceedings on file

Proceedings overview

One AIA trial proceeding has been filed against US patent 10221780, IPR2025-01185, which resulted in a denial of institution. This outcome indicates the patent has survived a challenge, offering a stronger defensive posture for the patent owner, as its claims remain unadjudicated and presumptively valid through this proceeding.

IPR2025-01185 — MWE Investments, LLC et al. v. Champion Power Equipment Inc.

• Type: Inter Partes Review
• Filed: 2025-07-22
• Status: Institution Denied. The PTAB declined to institute the inter partes review on 2026-01-16.
• Judge panel: The institution decision was issued under the authority of John A. Squires, Under Secretary of Commerce for Intellectual Property and Director of the United States Patent and Trademark Office. Specific PTAB judges forming a panel are not typically named in Director-level summary notices for routine institution decisions.
• Petition grounds: The petition challenged claims of US Patent 10221780. While the specific claims, prior art, and statutory bases (§ 102 / § 103) are not detailed in the available summary, the denial was based on a review of the merits, meaning the petitioner failed to show a reasonable likelihood of prevailing with respect to at least one challenged claim.
• Institution decision: Denied on 2026-01-16. The Director, after reviewing the merits, found that the petitioner had not shown a reasonable likelihood of prevailing with respect to at least one of the challenged claims. This denial was identified as "Not Instituted - Merits", distinguishing it from denials based purely on discretionary factors. Under the updated PTAB procedures in 2025, institution decisions have undergone a bifurcated approach, with the Director making a decision on discretionary grounds and then on the merits.
• Final Written Decision: Not applicable, as institution was denied.
• Settlement / termination: While MWE Investments, LLC (MWE) and Champion Power Equipment, Inc. (Champion) reached a settlement agreement in related litigation (the "MWE Litigation") and MWE sought to withdraw from several IPRs, including IPR2025-01185, Generac Power Systems, Inc. also remained a petitioner in this IPR and did not independently seek to withdraw, so the IPR was not terminated on this basis.
• Appeal: No Federal Circuit appeal has been noted since institution was denied. Under 35 U.S.C. § 314(d), institution decisions are generally nonappealable.
• Defensive value: The denial of institution for IPR2025-01185 on the merits means that all claims of US10221780 remain intact and were not subject to a full trial at the PTAB. For a defendant facing assertion of this patent, this indicates that an IPR-based defense using the same or substantially similar grounds that were presented in this petition might be more challenging, as the PTAB Director has already found the petition insufficient to warrant a trial on the merits.

Strategic summary

All claims of US10221780 are currently SUSTAINED, as the single IPR filed against it, IPR2025-01185, resulted in a denial of institution on the merits on 2026-01-16. This means no claims were invalidated, nor were any held patentable through a Final Written Decision, leaving the entire scope of the patent untroubled by this particular PTAB challenge.

Regarding the estoppel landscape, since IPR2025-01185 was denied institution, the statutory estoppel provisions of § 315(e)(2) generally do not apply to the petitioners (MWE Investments, LLC et al. and Generac Power Systems, Inc.). This means that they are not barred from raising the same or reasonably could have raised prior-art grounds in future district court litigation or a subsequent PTAB proceeding. However, the denial on the merits suggests that the PTAB Director found the petition's arguments unpersuasive, which could make it more difficult for a subsequent petition to succeed on similar grounds. For a defendant currently being asserted against, this implies that a wide array of prior-art grounds remain available, provided they meet the institution thresholds if pursued through a new IPR.

There are no apparent pattern signals of multiple IPRs from the same petitioner against this specific patent that proceeded to institution, although MWE Investments, LLC and Generac Power Systems, Inc. were involved in multiple IPRs against Champion Power Equipment Inc.'s patents generally. The PTAB has recently implemented a more restrictive, policy-driven approach to IPR institution, including increased discretionary denials and centralized control by the Director. This specific denial was on the merits.

Recommended next steps

• Monitor the USPTO PTAB E2E portal for any further proceedings or updates related to US10221780.
• Given the denial of institution on the merits, a potential defendant should attempt to access the full institution decision for IPR2025-01185 (Paper 12) from the USPTO PTAB E2E system (https://ptab.uspto.gov/#/search/documents) to understand the Director's specific reasoning for finding the petition insufficient. Understanding these details is crucial for informing any future invalidity strategies.
• Consider conducting an independent prior art search to identify new and compelling art that was not raised, or could not have been reasonably raised, in the denied IPR, should a new PTAB challenge be contemplated.
• The absence of further PTAB activity beyond this denial is a signal that the patent has weathered an initial challenge. However, it does not preclude future challenges.

Inventors

• Mark J. Sarder (Champion Power Equipment Inc.)
• Aleko D. Sotiriades (Champion Power Equipment Inc.)
• James J. Dehn (Champion Power Equipment Inc.)
• Leigh Jenison (Champion Power Equipment Inc.)

It is highly probable that all inventors were employed by Champion Power Equipment Inc. at the time of filing, as patent rights typically vest in the inventor initially but are often assigned to employers through employment agreements. Champion Power Equipment's engineering and R&D are based in Milwaukee, Wisconsin.

Original assignee

The original assignee named on the issued patent is Champion Power Equipment Inc..

Champion Power Equipment Inc. designs and manufactures a wide range of power equipment, including portable generators, home standby generators, inverter generators, engines, winches, and log splitters. They are known for their dual-fuel technology in generators, which is directly related to the claims of US10221780.

Champion Power Equipment Inc. is currently an operating company and has remained privately held since its founding in 2003.

Assignment timeline

• 2015-06-12 (executed) / recorded 2015-06-12 — Reel 035546/0995
  • Conveyance: Assignment
  • Assignor: DEHN, JAMES J.; JENISON, LEIGH; SARDER, MARK J.; SOTIRIADES, ALEKO D.
  • Assignee: Champion Engine Technology, LLC
  • Correspondent: Leigh J. Fulwood, Champion Power Equipment Inc., 12039 Smith Ave., Santa Fe Springs, CA 90670. This correspondent appears multiple times in this chain.
  • Context: Internal transfer from inventors to a related entity.
• 2018-11-29 (executed) / recorded 2018-11-29 — Reel 046460/0279
  • Conveyance: Assignment
  • Assignor: Champion Engine Technology, LLC
  • Assignee: CHAMPION POWER EQUIPMENT, INC.
  • Correspondent: Leigh J. Fulwood, Champion Power Equipment Inc., 12039 Smith Ave., Santa Fe Springs, CA 90670. This correspondent appears multiple times in this chain.
  • Context: Internal transfer/reorganization.

Timeline diagram

timeline
    title Ownership of US 10221780
    2015 : Inventors assigned to Champion Engine Technology LLC
    2018 : Assigned to Champion Power Equipment Inc
    2019 : Patent issued

NPE / troll-pattern signals

1. Shell-entity transfer — Not present. Both Champion Engine Technology, LLC and CHAMPION POWER EQUIPMENT, INC. appear to be related operating entities, with the patent eventually returning to the main operating company.
2. Known asserter in the chain — Not present. Neither Champion Engine Technology, LLC nor CHAMPION POWER EQUIPMENT, INC. are listed as known NPEs by Unified Patents or RPX.
3. Repeat correspondent across the chain — Present. Leigh J. Fulwood of Champion Power Equipment Inc. (12039 Smith Ave., Santa Fe Springs, CA 90670) is listed as the correspondent for both assignments recorded on 2015-06-12 (Reel 035546/0995) and 2018-11-29 (Reel 046460/0279). This indicates a consistent internal legal representation for Champion Power Equipment's patent activities.
4. Cascading transfers — Not present. There are only two recorded assignments in the chain, spaced over three years.
5. Pre-litigation transfer — Unclear. While there is litigation associated with this patent (mentioned on Google Patents), without specific filing dates for those cases, it's not possible to definitively state if any assignment occurred within 6 months prior to a lawsuit.
6. Bankruptcy fire-sale — Not present. Champion Power Equipment Inc. remains an active, privately held company.
7. Privateering — Not present. There is no evidence in the assignment records or public information to suggest a privateering arrangement.
8. Defensive aggregator (anti-NPE) — Not present. The chain does not terminate at a known defensive aggregator.

Verdict

Operating-company assertion. The patent was initially assigned from the inventors to Champion Engine Technology, LLC, and subsequently to Champion Power Equipment, Inc. Champion Power Equipment Inc. is an active operating company that manufactures and sells generators incorporating dual-fuel technology, which is the subject of this patent. The consistent correspondent across the assignments also points to internal management of the patent portfolio by an operating company.

Verification: https://assignmentcenter.uspto.gov/

I'll research US patent 10221780 and its cited prior art references, verifying key details via live search.

Let me research the remaining high-relevance references and the IPR grounds.

Prior Art Analysis — US 10,221,780 B2

"Dual fuel lockout switch for generator engine"

1. Patent Identification (USPTO)

A search for the specific number returned the following, confirming the record:

[cite: US10221780B2, Application No. 14/738,060, filed 2015-06-12, granted 2019-03-05; PATENT # 10221780, CONFIRMATION # 9670, FILING DATE 06/12/2015]

Prosecution correspondence was handled through Ziolkowski Patent Solutions Group, SC (Port Washington, WI). [cite: ZIOLKOWSKI PATENT SOLUTIONS GROUP, SC (ZPS) 136 S WISCONSIN ST PORT WASHINGTON, WI 53074]

Note on "most relevant prior art": The examiner-cited art (57 references) is reproduced below. Because the task is § 102-focused, I must be candid up front: no single cited reference discloses every element of independent Claim 1, 8, or 15, so none is a true anticipation reference. They are § 103 prior art. The genuinely anticipatory art for this family surfaced in the petitioner's record against the sibling '034 patent (not in this patent's own citation list) and is flagged in Section 5.

2. Legal Standard Applied

Under 35 U.S.C. § 102, a claim is anticipated only if a single reference discloses each and every claimed element, arranged as in the claim. A reference that discloses only some elements, or that requires combination with another reference, cannot anticipate — it is § 103 fodder.

The claim elements that drive this analysis are:

• [1.0–1.3] A mechanical fuel valve, actuable between two positions, that routes a first fuel source OR a second fuel source and prevents simultaneous communication.
• [1.4] A fuel lockout apparatus configured to (a) physically prevent the second fuel source from coupling to the second fuel line while the valve is in the first position, and (b) permit coupling in the second position.
• [3–4] The lockout is a flange rigidly coupled to the valve, rotating transversely across the second-fuel inlet.
• [5] Quick-disconnect hose coupling at the second-fuel inlet.
• [8.4 / 15] The lockout prevents actuation of the valve back to the first position while the second fuel source is coupled/in communication.

Elements [1.4], [3–4], and the "prevents actuation back" interlock of [8.4]/[15] are the points of novelty. The cited art is saturated with valve-based fuel selection (solenoids, selector switches, check valves), but essentially silent on a mechanical interlock that blocks the physical coupling of the gaseous-fuel connector.

3. The Cited References — "Citations (57)"

The Google Patents citation table in the source document listed 54 entries before the fetched text was truncated; three of the stated 57 were not displayed. The table below reproduces the 54 with priority/publication dates, a description, and the § 102 significance. "Anticipates?" answers for the independent claims (1/8/15) unless a dependent claim is identified; a "No" reflects a missing limitation, not irrelevance.

3.1 Early priming / fuel–air control art (1954–1975)

3.2 Core dual-fuel selection art (1979–1986) — most § 103-relevant cluster

3.3 Electronic fuel-injection and carburetor era (1987–2000)

3.4 Fuel cutoff solenoid / regulator art (1997–2005)

3.5 Generator / bi-fuel control art (2001–2013)

Truncation caveat: the source document states "Citations (57)" but the fetched table displayed only the 54 entries above (through US20140238340A1). Three citations were not retrieved and cannot be analyzed here.

4. Detailed § 102 Assessment of the Closest References

None of these meets the "single reference, every element" threshold:

US4463735A (GM) — closest to claims 1 and 6 on the routing logic. Its switching valve assembly (16) has a double-ended valve (36) that "interrupt[s] liquid phase fuel flow… and direct[s] vapor phase fuel" (and vice versa), each path "obstructing flow" from the other. This reads on Claim 1 elements [1.1] and [1.3] and on Claim 6 ("not simultaneously delivered"). Critically, however, it does not disclose element [1.4]: nothing in the reference prevents the second fuel source from coupling to the second fuel line, nor is there any structure that blocks a fuel inlet or connector. [cite: US4463735A]

US4489699A (Outboard Marine) — closest on "interrupts the first fuel source." Its control means energizes a liquid control valve (43) in the liquid position and de-energizes a gaseous control valve (45) in the gas position — i.e., selecting one fuel closes the other. This reads on [1.3] but is an electro-mechanical valve scheme, not a mechanical lockout of a physical coupling, and it does not "prevent actuation of the mechanical fuel valve to the first position" per Claims 2/15. [cite: US4489699A]

US6276345B1 (Kohler) — closest on non-simultaneous liquid/gas delivery in a carbureted engine. Fuel selection switch (15) cuts off LPG on gasoline and cuts off gasoline on LPG; gas cut-off solenoid (36); pressure regulator (45). This reads on Claim 6 and, in part, Claim 7 (liquid/gas) and Claim 11 (regulator). Again, the disconnect is via valves/solenoids, and the reference is silent on element [1.4] and on the quick-disconnect coupling with a physical blocker (Claims 3–5). [cite: US6276345B1]

US4373493A / US5816224A (Welsh) and US4335697A (McLean) are generic dual liquid/gas supply teachings and do not approach the lockout limitation.

Conclusion on the 57: every cited reference is either (i) unrelated engine/fuel-injection art, or (ii) dual-fuel delivery/selection art that prevents simultaneous flow via valves or solenoids. Not one discloses the "fuel lockout apparatus" that mechanically prevents coupling of the second fuel source (element [1.4]), which is precisely the limitation that distinguishes Claims 1/8/15. This is consistent with the fact that the only asserted validity challenge to date, IPR2025-01185, was denied institution (see previously generated PTAB section).

5. Higher-Relevance Art Discovered in the Family's Litigation Record

The prior art actually asserted against this patent family appears in the petitioner's IPR papers against the sibling '034 patent (US10393034), not in the '780 citation list. These deserve flagging because they are the art a challenger to '780 would most likely build on:

• US 1,931,698 (Holzapfel), filed 1931 — "a fuel system embodying the supplying of liquid fuel and gaseous fuel to an engine in alternation at will," in which a "rod or wire 47" controls both the liquid and gaseous valves and the liquid cutoff (14) sits downstream from the carburetor float chamber. This is the seminal "alternation at will" reference and is a serious § 102/§ 103 candidate against generic dual-fuel-selector claims — but it still lacks the coupling lockout of '780's Claims 1/8/15. [cite: "a fuel system embodying the supplying of liquid fuel and gaseous fuel to an engine in alternation at will"; A "rod or wire 47" controls both the liquid and gaseous valves]
• Nakafushi (LPG cut valve 18, vaporizer 14) — cited as a primary reference in the family IPRs. [cite: Nakafushi's LPG cut valve 18; Nakafushi discloses vaporizer 14]
• Jungmann — discloses a generator running on gasoline or propane; used to supply the "generator" element. [cite: Jungmann discloses an engine with a gasoline or propane fuel-delivery system in a generator]
• Parlatore / Bernhardsson — cited for regulator arrangements and solenoid fuel valves respectively. [cite: Bernhardsson's solenoid for Nakafushi's LPG cut valve 18]
• LP‑Gas Code Handbook (8th ed., 2008) — cited for the conventionality of quick connectors ("Fittings used to connect hose assemblies to piping and valves without the use of tools"), relevant to dependent Claim 5. [cite: Quick Connectors. Fittings used to connect hose assemblies to piping and valves without the use of tools.]
• US 4,492,207 (Hallberg) — dual methanol/gasoline system with a fuel selector switch (55) and solenoid (58); a recurring "fuel selector" reference across the family. [cite: fuel selector switch 55; solenoid 58]

Additionally, the applicant's own family repeatedly cites US10393034B2, US4538240, and US5986944 — the first being a Champion family member — showing the examiner treated the family as closely related art. [cite: US10393034B2 (en) * 2015-06-12 2019-08-27 Champion Power Equipment, Inc. Fuel system for a multi-fuel internal combustion engine]

6. Synthesis

Explicit Uncertainty / Limitations

• The citation table in the source document was truncated at 54 of the stated 57 references; the three unretrieved citations (and the truncated assignee/title for US20140238340A1) could not be analyzed.
• Descriptions for references I did not individually verify by live search are drawn from the reference titles and dates as listed in the '780 record; treat those as title-level characterizations.
• I did not obtain the full text of the IPR2025-01185 petition or its Grounds; the art listed in Section 5 comes from the related family IPR filings (against US10393034), so it is indicative of the challenger's art strategy rather than a verbatim record of the '780 proceeding.
• All dates for the underlying references are as reported in the Google Patents citation table for US10221780; the independently verified ones (US4463735A: filed 1983-06-02/issued 1984-08-07; US4502453A: filed 1984-04-03/issued 1985-03-05; US4489699A: priority 1981-10-23/issued 1984-12-25; US6276345B1: 1998-12-23/2001-08-21) matched the record.

I'll pull details on the key examiner-cited references so the obviousness combinations are grounded in actual disclosure rather than titles alone.

Now let me check the IPR2025-01185 record for the actual grounds/art asserted, plus the Kohler and Monros references.

Let me try to identify the primary references asserted in the (denied) IPR so I can distinguish examiner-cited art from IPR art.

Obviousness Analysis — US 10221780 under 35 U.S.C. § 103

Building on the Prior Art, PTAB, and Litigation sections above. Where I use art that appears in the live IPR record rather than the examiner-cited list, I label it explicitly.

1. Legal framework and level of ordinary skill

The patent has a priority date of 2015-06-12 and is an AIA patent, so §§ 102(a)(1)/(a)(2) and 103 apply as amended. The Graham/KSR framework controls: scope and content of the prior art, differences between the prior art and the claims, PHOSITA level, and objective indicia. Critically, under KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398 (2007), a combination is obvious where (a) the elements were known, (b) there was a known problem with an obvious solution, and (c) a POSITA had a reasonable expectation of success. MPEP § 2143 lists the recognized rationales (known technique improvement; simple substitution of one known element for another; use of a known technique to improve a similar device; "obvious to try"). Notably, the patent's own specification confirms the elements were individually known — it frames the invention as solving a known problem (simultaneous delivery causing an "overly rich air-fuel ratio" during cross-over switching) using known hardware (a manual fuel valve, a quick-disconnect coupling 50, a fuel cut solenoid 63, off-the-shelf primary/secondary regulators 42, 44).

PHOSITA: a person with a bachelor's degree in mechanical engineering (or equivalent) and 2–4 years' experience designing small air-cooled spark-ignition engine fuel systems for portable power equipment, or equivalent work experience — consistent with the small-engine dual-fuel literature (e.g., the SAE paper "Development of a Dual Fueled (Gasoline or Propane) Air Cooled, Spark Ignited Utility Engine," 1999-01-3335, describing a Kohler 725cc engine converted to gasoline/propane with a user-actuated switch and corresponding to the Kohler 6,276,345 family).

2. Prior art landscape (from the Prior Art section), with two corrections

The examiner-cited art in the Prior Art section establishes nearly every element of claims 1, 6, 7, 11–14:

Corrections / contradictions to flag (per the earlier Prior Art section):

1. US 4,463,735 A is mischaracterized in the Prior Art section. It is not a gasoline/LPG three-way-valve system. Its actual disclosure is a single pressurized tank containing methane and propane, with a diaphragm-actuated switching valve assembly 16 that automatically directs vapor-phase vs. liquid-phase fuel to the metering apparatus based on tank pressure (1400 kPa threshold). It is relevant only as generic evidence that valving between two fuels was routine; it is weak art for claims 1/8/15 because it involves no user-selected mechanical valve handle and no second fuel line that is physically coupled/uncoupled by the operator. This should be corrected before relying on it.
2. US 2014/0202430 A1 (Monros) is the correct citation for the "overly rich mixture on cross-over" problem the '780 patent recites; the earlier section's reliance on it for that point is sound.
3. CN 206,694,124 U is not prior art. Filed 2017-02-24, published 2017-12-01 — both after the 2015-06-12 priority date. It cannot anticipate or be combined under § 103 absent an earlier priority showing. (The Prior Art section reached the same conclusion; I confirm it.)
4. PTAB record discrepancy to note: the PTAB section states the IPR2025-01185 institution denial date as both 2026-01-16 and 2026-03-11. The ipverse case record lists the institution decision date as 2026-01-16, which I treat as the better-supported date.

Art surfaced from the live IPR record (not examiner-cited; label separately): Champion's preliminary-response excerpt in the '780 IPR identifies the petitioners' grounds as DuroMax (Grounds 1, 5), Hallberg (Grounds 2A, 2B), Rumao (Grounds 3–4, 6), with secondary references Eldson and Parlatore; it also notes the art is asserted to be cumulative of Sugimoto. Hallberg is US 4,492,207 ("Dual fuel system"), which discloses a manually actuated fluid dual valve 300 whose rotating spool 306 is driven by control 301 / control cable 302, with a vacuum-actuated "positive lock-off" of the liquified-fuel inlet valve. I could not retrieve the full IPR2025-01185 petition, so I do not treat its exact element mapping as established — treat the Hallberg mapping below as my analysis, not as the Board's.

3. Where the claims are strong and where they are exposed

• Strong ground for the patent (claims 1, 8, 15): the physical limitation — the lockout "prevent[s] the second fuel source from coupling to the second fuel line" (claim 1) and "prevents actuation of the mechanical fuel valve to the first position when the second fuel source communicates/coupled" (claims 2, 8, 15). Every reference in the Prior Art section (and Hallberg) discloses flow-based lockout (solenoids, spool seals, vacuum lock-offs). Apparatus claims cover what a device is, not what it does — so an obviousness case requires a secondary teaching of a structural obstruct/blocks-connection element, or a KSR "known technique" rationale.
• Weak ground for the patent (claims 3–6, 9–14): the dependent claims recite conventional expedients — a flange (3), a rotating flange (4), a quick-disconnect coupling (5), non-simultaneous delivery (6), an off-board regulator system (11–12), and a quick-disconnect at the regulator outlet (13). Each is individually disclosed or strongly suggested by the art above.

4. Combination scenarios

Combination A — US 6,276,345 B1 + US 4,489,699 A (primary), further in view of US 3,718,000 A (Walker).

• Disclosure: '345 gives the dual-fuel generator, the selector switch, and per-fuel cut-off valves ('345, cols. 2–3); '699 gives the selector switch with normally-closed energizable valves and sequencing to avoid simultaneous flow; Walker gives a single mechanical actuator (control rod 26) that opens one fuel valve while tightly closing the other.
• Motivation: all three are in the same field (dual-fuel spark-ignition engines) and address the same failure mode (fuel overlap → rich mixture, hard starting). Walker expressly teaches the mechanical alternative to solenoids, and Hallberg's own background criticizes electrically operated valves as "the weakest link," "frequently [not working] well in the environment of the engine" — a recognized reason to convert an electrical lockout to a mechanical one (substitution of a known element for a known element; KSR).
• Result: renders claims 1, 6, 7, 15 (and, with the solenoid art, the element-63 background) obvious. Gap: none of A teaches blocking coupling.

Combination B — A + a connection-guard/interlock teaching, or KSR "known technique."
The '780 patent's own specification concedes that the lockout structure is a flange (61) attached to a rotating selector handle (56) that sweeps transversely over the LPG inlet (59). Two independent routes:

1. Hallberg (US 4,492,207) as the valve subcombination — a fluid dual valve whose spool 306 rotates between "gasoline" (Fig. 10) and "propane" (Fig. 11) positions, with control 301/cable 302 "coupled to" the valve. A POSITA seeking a mechanical lockout of the LPG hose connection would, with predictable results, mount an abutment/cover on Hallberg's control 301 or spool 306 so that in the gasoline position the cover occludes the LPG inlet, and in the propane position the connected hose physically blocks return of the control — an "improvement of a known technique" applied to a known device, with no change in the principle of operation (MPEP 2143.01(IV)).
2. Interlock/mistake-proofing art — the IPR ecosystem around this family asserts key-based and selector-based interlocks (e.g., DeVries, US 7,481,087, asserted in IPR2025-01228), and the DuroMax-class generator art shows a dual-fuel generator in which the LPG hose must be attached before LPG operation. Mistake-proofing a fuel connection so that only one fuel can be connected at a time is a recognized design objective; the claimed structure (a rotating cover on the existing handle) is the natural and cheapest way to achieve it.

• Result: renders claims 1, 2, 3, 4, 5, 8, 15 obvious, if the secondary teaching is accepted. This is the crux of any § 103 case.

Combination C — A + US 5,320,078 A + US 6,453,877 B1 + US 6,276,345 B1.
'078 teaches remote mounting of a fuel pressure regulator; '877 teaches two-regulator fuel delivery; '345 shows two-stage vaporizer/regulator hardware in dual-fuel form. Motivation: the '780 specification itself states the off-board location exists "to reduce size and cost of the generator," and that off-board mounting permits use of "off-the-shelf components" — an explicit statement of the design trade-off a POSITA would already appreciate. This renders claims 11, 12, and 13 obvious (with a conventional quick-disconnect at the regulator outlet).

Combination D — US 6,276,345 B1 or US 4,489,699 A in view of US 6,213,083 B1 / US 6,401,685 B1 (float-bowl shut-off solenoids).
Motivation: to prevent residual gasoline in the float bowl feeding the engine during LPG start (the exact rationale recited in the '780 specification for solenoid 63). Renders the solenoid-related subject matter of the specification (and the corresponding limitations if imported) obvious.

5. Claim-by-claim assessment

6. Rebuttal posture and objective indicia

Champion's strongest responses, all reflected in the record, are:

1. § 325(d)/cumulativeness. Champion argued the IPR art was "cumulative to art already considered during prosecution" and that the petitioners could not show material examiner error. This is persuasive against repeat art but is not a § 103 defense on the merits.
2. No art teaches the physical coupling interlock. The examiner allowed the claims over 57 references, and the Board denied institution on the merits on 2026-01-16 — evidence (not dispositive, and non-appealable under § 314(d)) that the asserted art did not render the "prevent coupling" limitation obvious.
3. Claim-construction risk to petitioners. The record shows the term "fuel lockout apparatus" (and "mechanical fuel valve," "from coupling"/"to couple," "communicate") was disputed across the parallel litigations, and Director Squires vacated two Champion-related institutions in February 2026 for inconsistent claim constructions between IPR and district court. A petitioner taking inconsistent positions on "coupling" would face the same problem.
4. Objective indicia (to be developed). Champion has sold dual-fuel generators embodying the lockout at volume since ~2015 (commercial success), and the "copying" narrative in the district court record (documents concerning a 2014 Cabela's generator demonstration, and Generac's alleged copying) is available as evidence of copying, though a nexus showing to the lockout flange specifically — rather than to dual-fuel capability generally — will be required.

7. Bottom line

• Claims 6, 7, 11–14 are the most vulnerable — they are directed to the generic dual-fuel architecture and off-board regulator arrangement squarely disclosed by US 6,276,345 B1, US 4,489,699 A, US 5,320,078 A and US 6,453,877 B1, with motivation supplied by the patent's own stated purposes (avoid rich mixtures; reduce size/cost; use off-the-shelf regulators).
• Claims 1, 2, 3, 4, 5, 8, 9, 10, 15 survive only if the "prevents coupling / prevents actuation" interlock limitation is read narrowly as requiring a structural obstruction at the fuel inlet. A § 103 case is available via Hallberg (US 4,492,207) plus a connection-guard/interlock teaching, but it is a secondary-reference-dependent case, not a clean single-reference anticipation. This is consistent with the Board's merits denial of IPR2025-01185 and the examiner's allowance over 57 references.
• Not usable as prior art: CN 206,694,124 U (post-dates the 2015-06-12 priority date).
• Needs correction before reuse: the characterization of US 4,463,735 A in the earlier Prior Art section (it is a vapor/liquid-phase automatic switching valve for a mixed methane/propane tank, not a user-selected gasoline/LPG valve).

(Incidental confirmation of a prior section: the certificate-of-correction request in the PTAB record states "The Patent Term Adjustment is 605 day(s)," which matches the ~1 year 7 months derived in the Extensions section and the 2037-02-06 adjusted expiration.)

Patent Term Adjustments (PTA) and Patent Term Extensions (PTE) for US10221780

Patent Term Adjustment (PTA):
Patent Term Adjustment (PTA) is granted to compensate for certain delays incurred by the USPTO during the prosecution of a patent application. These delays are categorized as "A," "B," and "C" delays, relating to specific timeframes for USPTO actions (e.g., issuing a first office action within 14 months, issuing a patent within 36 months of filing). Any such extensions can be reduced or eliminated by delays caused by the applicant.

The provided patent text for US10221780 states an "Adjusted expiration" date of 2037-02-06. This indicates that Patent Term Adjustment has likely been applied to the patent, extending its term beyond the standard 20 years from its earliest filing date. The specific details of the PTA calculation (e.g., the number of days of "A", "B", and "C" delays, and any applicant delays) are typically found in the "Issue Notification Letter" and the patent's file wrapper in USPTO's Patent Center.

Patent Term Extension (PTE):
Patent Term Extension (PTE) is available for patents covering certain products (e.g., human drugs, food or color additives, medical devices, animal drugs) to restore some of the patent term lost during premarket regulatory review by agencies like the FDA.

US Patent 10221780, titled "Dual fuel lockout switch for generator engine," pertains to mechanical engineering and internal combustion engines, not to products requiring premarket government approval from a regulatory agency such as the FDA. Therefore, it is highly unlikely that US10221780 would be eligible for a Patent Term Extension (PTE) under 35 U.S.C. § 156.

Continuation and Divisional Applications

• Continuation Applications: A continuation application allows an applicant to pursue additional claims based on the same specification and drawings as a previously filed "parent" application, while retaining the parent's priority date. Continuation applications must be filed before the parent application issues or becomes abandoned.
• Divisional Applications: A divisional application is filed when a patent application claims more than one independent and distinct invention, and the USPTO requires the applicant to restrict the claims to one invention. The non-elected inventions can then be pursued in divisional applications, sharing the same priority date as the original application.

The provided "Priority Applications" and "Related Child Applications" sections in the patent text list several applications that claim priority from or are related to US10221780 (Application Number US14/738,060).

Priority Applications of US10221780 (US14/738,060):
US10221780 itself is the primary patent from application US14/738,060. The "Priority Applications" section of the Google Patents page lists US14/738,060 as its own priority, which is typical for the initial application in a family.

Applications Claiming Priority from US14/738,060:
The "Priority Applications" section also lists other applications that claim priority from the same priority date as US14/738,060 (June 12, 2015):

• US14/925,441 (US10697398B2) - "Batteryless dual fuel engine with liquid fuel cut-off"
• CA2930628A (CA2930628C) - "Batteryless dual fuel engine with liquid fuel cut-off"
• CA2930627A (CA2930627A1) - "Dual fuel lockout switch for generator engine"
• CN201610392379.4A (CN105971744A) - "Dual-fuel lock switch for generator engine"
• CN201610407234.7A (CN106089421A) - "There is the engine of double fuel without battery of liquid fuel stopper"
• US15/285,215 (US10393034B2) - "Fuel system for a multi-fuel internal combustion engine"
• US15/332,264 (US10167789B2) - "Dual fuel engine with liquid fuel cut-off"
• US16/191,503 (US11530654B2) - "Off-board fuel regulator for generator engine"
• US16/358,822 (US10697379B2) - "Tri fuel gen"
• US16/783,455 (US11492985B2) - "Off-board fuel regulator for generator engine"
• US16/946,438 (US11143145B2) - "Batteryless dual fuel engine with liquid fuel cut-off"
• US16/946,439 (US11143120B2) - "Fuel system for a multi-fuel internal combustion engine"
• US17/937,046 (US11840970B2) - "Dual fuel generator with remote regulator"
• US18/183,734 (US11905895B2) - "Dual fuel lockout switch for generator engine"
• US18/443,487 (US20240183319A1) - "Dual fuel lockout switch for generator engine" (Pending)
• US19/026,996 (US20250154911A1) - "Dual fuel lockout switch for generator engine" (Pending)

Related Child Applications (Explicitly listed as Continuation or Continuation-In-Part):
The "Related Child Applications" section specifically identifies the following:

• US14/925,441 (US10697398B2) - "Batteryless dual fuel engine with liquid fuel cut-off" is a Continuation-In-Part.
• US16/191,503 (US11530654B2) - "Off-board fuel regulator for generator engine" is a Continuation.

These entries clearly indicate that Champion Power Equipment Inc. has actively managed its patent portfolio through continuation and continuation-in-part applications, deriving multiple patents from the original filing of US10221780.

Related Family Members

The "Family Applications" section on the Google Patents page lists several related applications that share the same priority date (June 12, 2015), indicating they are part of the same patent family (Family ID=57010162). These include:

• US14/738,060 (US10221780B2) - Dual fuel lockout switch for generator engine (This patent)
• US16/191,503 (US11530654B2) - Off-board fuel regulator for generator engine
• US16/783,455 (US11492985B2) - Off-board fuel regulator for generator engine
• US17/937,046 (US11840970B2) - Dual fuel generator with remote regulator
• US18/183,734 (US11905895B2) - Dual fuel lockout switch for generator engine
• US18/443,487 (US2024018331A1) - Dual fuel lockout switch for generator engine (Pending)
• US19/026,996 (US20250154911A1) - Dual fuel lockout switch for generator engine (Pending)

The "Country Status" section also lists foreign family members:

• CN (1): CN105971744A - Dual-fuel lock switch for generator engine
• CA (1): CA2930627A1 - Dual fuel lockout switch for generator engine

These represent the broader international patent family covering similar or related inventions stemming from the original priority application.

Projected Expiration Date

The "Legal status" section of the Google Patents page for US10221780 explicitly states that the patent is "Active" and "expires 2037-02-06". This date already includes any Patent Term Adjustment (PTA) applied to the patent. [cite: The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed., Active , expires 2037-02-06]

The standard patent term for utility patents filed on or after June 8, 1995, is 20 years from the earliest filing date of the application. The original filing date for US10221780 (Application No. US14/738,060) is June 12, 2015. A 20-year term from this date would result in an expiration around June 12, 2035. The stated expiration date of February 6, 2037, indicates that the patent has received approximately 1 year and 7 months of Patent Term Adjustment. This adjustment would be due to delays by the USPTO during the examination process, consistent with PTA provisions.

No information suggests the application of a terminal disclaimer that would shorten the patent term.