Patent 8842454B2

Assignment history

Inventors, original assignee, and the chain of ownership recorded with the USPTO — including the correspondent attorney who recorded each assignment, since shell-LLC chains often share one repeat-player attorney even when the entity names look unrelated. Surfaces NPE / patent-troll patterns: shell-entity transfers, known asserters in the chain, repeat correspondent fingerprints, pre-litigation assignments, and bankruptcy fire-sales.

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Assignment history

Inventors, original assignee, and the chain of ownership recorded with the USPTO — including the correspondent attorney who recorded each assignment, since shell-LLC chains often share one repeat-player attorney even when the entity names look unrelated. Surfaces NPE / patent-troll patterns: shell-entity transfers, known asserters in the chain, repeat correspondent fingerprints, pre-litigation assignments, and bankruptcy fire-sales.

✓ Generated

Inventors

  • Brian Johnson: Likely SolarBridge Technologies Inc. (original assignee)
  • Philip Krein: Likely SolarBridge Technologies Inc. (original assignee)
  • Alexander Gray: Likely SolarBridge Technologies Inc. (original assignee)
  • Patrick L. Chapman: Likely SolarBridge Technologies Inc. (original assignee)

No unusual patterns regarding inventor departures are immediately determinable from the patent text alone.

Original assignee

The original assignee named on the issued patent is SolarBridge Technologies Inc.

SolarBridge Technologies Inc. was a company that designed and manufactured microinverters for solar panels. They shipped products embodying the claims, specifically AC modules with integrated microinverters for photovoltaic applications. Their primary line of business was power conversion electronics for solar energy. SolarBridge Technologies Inc. was acquired by SunPower Corporation in 2014. SunPower subsequently sold its microinverter business, including the SolarBridge portfolio, to Enphase Energy in 2018.

Assignment timeline

  • 2011-03-25 (executed) / recorded 2011-03-25 — Reel 025805/0064
    • Conveyance: Assignment
    • Assignor: Brian Johnson, Philip Krein, Alexander Gray, Patrick L. Chapman
    • Assignee: Solarbridge Technologies Inc.
    • Correspondent: Jeffrey B. Miller, FISH & RICHARDSON P.C., P.O. BOX 1022, MINNEAPOLIS, MN 55440-1022
    • Context: Assignment from inventors to the initial corporate assignee.
  • 2014-09-02 (executed) / recorded 2014-09-02 — Reel 032223/0446
    • Conveyance: Security Interest
    • Assignor: SOLARBRIDGE TECHNOLOGIES, INC.
    • Assignee: SILICON VALLEY BANK
    • Correspondent: R. Andrew Collins, MAYER BROWN LLP, PO BOX 2828, CHICAGO, IL 60690-2828
    • Context: Grant of a security interest, typically as collateral for financing.
  • 2014-12-19 (executed) / recorded 2014-12-19 — Reel 032644/0833
    • Conveyance: Release by Secured Party
    • Assignor: SILICON VALLEY BANK
    • Assignee: SOLARBRIDGE TECHNOLOGIES, INC.
    • Correspondent: R. Andrew Collins, MAYER BROWN LLP, PO BOX 2828, CHICAGO, IL 60690-2828. This correspondent recurs in this chain.
    • Context: Release of the security interest by Silicon Valley Bank.
  • 2014-12-19 (executed) / recorded 2014-12-19 — Reel 032644/0835
    • Conveyance: Assignment
    • Assignor: SOLARBRIDGE TECHNOLOGIES, INC.
    • Assignee: SUNPOWER CORPORATION
    • Correspondent: R. Andrew Collins, MAYER BROWN LLP, PO BOX 2828, CHICAGO, IL 60690-2828. This correspondent recurs in this chain.
    • Context: Acquisition of SolarBridge Technologies Inc. by SunPower Corporation.
  • 2018-09-10 (executed) / recorded 2018-09-10 — Reel 045869/0751
    • Conveyance: Assignment
    • Assignor: SUNPOWER CORPORATION
    • Assignee: ENPHASE ENERGY, INC.
    • Correspondent: Eric L. Miller, NIXON PEABODY LLP, 2500 ATRIUM ON THE COMMON, 500 SOUTH AVENUE, ROCHESTER, NY 14618
    • Context: Transfer of SolarBridge microinverter business and related patents from SunPower to Enphase Energy.
  • 2023-09-01 (executed) / recorded 2023-11-20 — Reel 060595/0426
    • Conveyance: Assignment
    • Assignor: ENPHASE ENERGY, INC.
    • Assignee: POWERBRIDGE NETWORKS, LLC
    • Correspondent: Steven W. Smith, SMITH & MITCHELL LAW FIRM, 1400 BROADWAY, SUITE 423, NEW YORK, NY 10018
    • Context: Transfer from operating company (Enphase Energy) to an LLC (Powerbridge Networks, LLC).
  • 2026-04-21 (executed) / recorded 2026-04-21 — Reel 066708/0426
    • Conveyance: Assignment
    • Assignor: POWERBRIDGE NETWORKS, LLC
    • Assignee: GRIDSCALE SOLUTIONS, LLC
    • Correspondent: Steven W. Smith, SMITH & MITCHELL LAW FIRM, 1400 BROADWAY, SUITE 423, NEW YORK, NY 10018. This correspondent recurs in this chain.
    • Context: Transfer between LLCs.

Timeline diagram

timeline
    title Ownership of US 8842454B2
    2011 : Inventors assign to SolarBridge
    2014 : SVB security interest
         : SVB releases interest
         : SolarBridge to SunPower
    2018 : SunPower to Enphase Energy
    2023 : Enphase Energy to PowerBridge Networks
    2026 : PowerBridge to GridScale Solutions

NPE / troll-pattern signals

  1. Shell-entity transfer — Present.

    • 2023-09-01 (executed) / recorded 2023-11-20 (Reel 060595/0426): Transfer from Enphase Energy, Inc. (an operating company) to PowerBridge Networks, LLC. The "LLC" suffix and the general absence of public product information for PowerBridge Networks suggests a licensing-focused entity.
    • 2026-04-21 (executed) / recorded 2026-04-21 (Reel 066708/0426): Transfer from PowerBridge Networks, LLC to GRIDSCALE SOLUTIONS, LLC. Again, the "LLC" suffix and lack of clear operating activities for GridScale Solutions, LLC points towards a shell entity.

  2. Known asserter in the chain — Unclear. Neither PowerBridge Networks, LLC nor GridScale Solutions, LLC immediately appear on widely published public NPE lists (like RPX or Unified Patents asserter directories) from a quick search. However, this does not definitively rule out their NPE status.

  3. Repeat correspondent across the chain — Present.

    • R. Andrew Collins of Mayer Brown LLP handled the Security Interest (Reel 032223/0446) and the subsequent Release and Assignment to SunPower (Reel 032644/0833 and 032644/0835).
    • Steven W. Smith of Smith & Mitchell Law Firm handled the transfer from Enphase Energy to PowerBridge Networks, LLC (Reel 060595/0426) and the subsequent transfer from PowerBridge Networks, LLC to GRIDSCALE SOLUTIONS, LLC (Reel 066708/0426). The recurrence of Steven W. Smith for two successive transfers involving "LLC" assignees is a strong signal.

  4. Cascading transfers — Present.

    • The transfer from Enphase Energy to PowerBridge Networks, LLC in September 2023 (recorded November 2023, Reel 060595/0426) followed by the transfer from PowerBridge Networks, LLC to GRIDSCALE SOLUTIONS, LLC in April 2026 (recorded April 2026, Reel 066708/0426) shows two consecutive assignments through LLCs within a relatively short period (less than 3 years between the executed dates, less than 2.5 years between recorded dates), with the same correspondent attorney, Steven W. Smith.

  5. Pre-litigation transfer — Not present. There is no information about current litigation for this patent in CAFC dockets for 2026, and a general search for litigation involving these new assignees and this patent doesn't immediately show filings within 6 months of the 2023 or 2026 transfers.

  6. Bankruptcy fire-sale — Not present. The transfers from SolarBridge to SunPower and then to Enphase were corporate acquisitions/sales of business units, not a bankruptcy fire-sale. The transfers to PowerBridge Networks, LLC and GridScale Solutions, LLC also do not appear to be bankruptcy-related.

  7. Privateering — Unclear. While Enphase Energy transferred the patent, there is no public information or SEC filing data available to suggest they are asserting on Enphase's behalf, or if Enphase is retaining a financial interest in future assertions.

  8. Defensive aggregator (anti-NPE) — Not present. The chain does not terminate at a known defensive aggregator like RPX or AST.

Verdict

NPE — moderate confidence

The patent has been transferred from operating companies (Enphase Energy) to an LLC (PowerBridge Networks, LLC) and subsequently to another LLC (GRIDSCALE SOLUTIONS, LLC), which is a shell-entity transfer signal. The same correspondent attorney, Steven W. Smith, handled both recent transfers to these LLCs (Reel 060595/0426 and 066708/0426), which is a strong repeat correspondent signal and contributes to the cascading transfers pattern. These elements strongly suggest the patent is now held by a non-practicing entity for potential assertion purposes.

USPTO Assignment Center search for US8842454B2: https://assignmentcenter.uspto.gov/patent/index.html

SunPower to Buy SolarBridge Technologies (PV-Tech): According to a PV-Tech article from November 19, 2014, SunPower announced it would acquire SolarBridge Technologies, strengthening its position in the microinverter market.
SunPower (SPWR) to Acquire SolarBridge Technologies (StreetInsider.com): A StreetInsider.com article from November 19, 2014, reports on SunPower's plans to acquire SolarBridge Technologies, noting SolarBridge's expertise in AC modules and microinverters.
Enphase Energy to acquire SunPower’s microinverter business (PV Magazine): An article from PV Magazine, dated October 10, 2018, details Enphase Energy's acquisition of SunPower's microinverter business, including the existing microinverter product line and intellectual property.

Generated 5/24/2026, 6:46:19 PM