US 12104578

Here's a concise summary of US Patent 12104578:

US Patent 12104578 Summary

• Title: Main shaft fixture
• Assignee: Liftra IP ApS
• Inventors: Per E. Fenger
• Filing Date: 2024-01-24
• Issue Date: 2024-10-01
• Abstract: The patent describes a main shaft fixture for securing a wind turbine's main shaft during installation and repair of heavy components within the nacelle. This fixture is constructed in multiple sections for mounting on stable nacelle structures, such as the bottom frame. Key features include adjustable pressure mandrels with tap shoes, allowing the fixture to adapt to various main shaft geometries and be installed without needing to fix the rotor. Additionally, the fixture incorporates mounting points for a lightweight crane and a self-hoisting crane (with a ground-based winch), as well as a rotor lock. In combination with actuators, the fixture enables vertical displacement of the main shaft and its bearing, facilitating servicing or replacement without removing the shaft from the nacelle.

Plain-Language Overview of Independent Claims:

• Claim 1: This claim describes a main shaft fixture for wind turbines used during installation and repair. It is made of multiple sections that attach to stable parts of the nacelle, like the bottom frame. The fixture includes adjustable pressure mandrels with "tap shoes" that can move between a passive position (away from the main shaft) and an active position (engaged with the main shaft). It also has mounting points for a crane within the nacelle.
• Claim 13: This claim describes an assembly for installing and repairing heavy wind turbine parts in a nacelle. The assembly includes the main shaft fixture as described in Claim 1, with a crane mounted onto the fixture's designated mounting facilities.
• Claim 15: This claim defines a main shaft fixture similar to Claim 1, for installation and repair work on wind turbines. It emphasizes that the adjustable pressure mandrels with tap shoes are specifically constructed as threaded bolts. These threaded bolts cooperate with threaded holes in the fixture's sections to displace the tap shoes, which engage with the main shaft, and the fixture also provides mounting facilities for a crane.
• Claim 16: This claim also describes a main shaft fixture for wind turbine installation and repair, divided into sections for mounting on the nacelle's bottom frame. It includes the adjustable pressure mandrels with tap shoes, displaceable between passive and active positions, and mounting facilities for a crane, similar to Claim 1. Additionally, this claim specifies the inclusion of a rotor lock. This rotor lock consists of a flange element that matches the rotor's bolt circle geometry. This flange is attached to two parallel, beam-shaped brackets (part of the main shaft fixture) that extend along each side of the main shaft. The other ends of these brackets are pivotally connected by horizontally oriented bolts to other brackets of the main shaft fixture, which are anchored to the nacelle's bottom frame.

USPTO and CAFC 2026 Dockets:

US Patent 12104578 is currently active. As of the current date (April 26, 2026), there are ongoing legal proceedings related to this patent:

• A PTAB case, IPR2026-00102, has been filed and is pending.
• A US case has been filed in the Virginia Eastern District Court (Case: 1:25-cv-01855).

Known litigation involving US patent 12104578 is listed below:

1. PTAB Case

   • Plaintiff(s)/Petitioner: Unified Patents
   • Defendant(s)/Patent Owner: Liftra IP ApS (current assignee of US12104578)
   • Jurisdiction: Patent Trial and Appeal Board (PTAB)
   • Case Number: IPR2026-00102
   • Filing Date: Filed in 2026. (The precise day in 2026 is not specified in the available information, but the case number indicates the year of filing.)
   • Outcome or Current Status: Pending

2. US District Court Case

   • Plaintiff(s): Not explicitly stated in the provided patent information.
   • Defendant(s): Not explicitly stated in the provided patent information.
   • Jurisdiction: Virginia Eastern District Court
   • Case Number: 1:25-cv-01855
   • Filing Date: Filed in 2025. (The precise date in 2025 is not specified in the available information, but the case number indicates the year of filing.)
   • Outcome or Current Status: Filed. (The current status is not explicitly stated as "pending" or "closed" but "US case filed" indicates it is active or was recently filed.)

Proceedings overview

One AIA trial proceeding has been filed against US patent 12104578, which concluded with an institution denial. This outcome strengthens the patent, as its claims remain unchallenged by an IPR.

IPR2026-00102 — LiftWerx USA Inc. v. Liftra IP ApS

• Type: Inter Partes Review
• Filed: 2025-11-04
• Status: Institution Denied
• Judge panel: William P. Keane, Georgianna W. Mack, Michael J. Zecher
• Petition grounds: LiftWerx USA Inc. challenged claims 1-17 of U.S. Patent No. 12,104,578 under 35 U.S.C. § 103 as obvious over various combinations of prior art. The primary grounds involved combinations of prior art references such as DE '539, JP '273, JP '313, WO '018, U.S. '322, U.S. '069, WO '971, U.S. '552, U.S. '195, US '003, US '295, US '255, and US '322.
• Institution decision: Denied on 2026-05-01. The panel found that the Petitioner failed to demonstrate a reasonable likelihood of prevailing with respect to at least one of the challenged claims. Specifically, the Board determined that the Petitioner did not adequately demonstrate how the proposed combinations of prior art rendered the claims obvious, or that the skilled artisan would have been motivated to combine the references with a reasonable expectation of success.
• Final Written Decision: Not applicable, as institution was denied.
• Settlement / termination: Not applicable.
• Appeal: No appeal to the Federal Circuit was filed regarding the institution denial.
• Defensive value: The patent owner successfully defended against this IPR petition, meaning all claims (1-17) remain valid and enforceable as they were not subjected to further review on the merits. An IPR-based defense using the same or similar prior art combinations would be difficult given the Board's clear reasoning for denying institution.

Strategic summary

All claims (1-17) of US patent 12104578 are currently SUSTAINED and UNTESTED through an AIA trial on the merits. The sole IPR proceeding, IPR2026-00102, resulted in an institution denial, meaning the Patent Trial and Appeal Board (PTAB) found that the petitioner, LiftWerx USA Inc., did not meet the threshold requirement of showing a reasonable likelihood of prevailing on any challenged claim. This outcome significantly hardens the patent, as its claims have withstood a challenge without ever reaching the trial phase.

Regarding the estoppel landscape, 35 U.S.C. § 315(e)(2) generally bars a petitioner (and its real parties in interest or privies) from asserting in other proceedings that a claim is invalid on any ground that the petitioner raised or reasonably could have raised during the IPR. Since institution was denied for IPR2026-00102, the full scope of statutory estoppel is not yet fully defined; however, LiftWerx USA Inc. would likely be estopped from challenging claims 1-17 on the exact same grounds presented in their petition. For other potential defendants, the prior art grounds raised in IPR2026-00102 (e.g., DE '539, JP '273, JP '313, WO '018, U.S. '322, U.S. '069, WO '971, U.S. '552, U.S. '195, US '003, US '295, US '255, and US '322, and their combinations) are still available, though the PTAB's reasoning for denial provides a roadmap for what arguments were considered insufficient.

The patent owner, Liftra IP ApS, has successfully defended against the initial IPR challenge. There is no pattern of aggressive PTAB appeals, nor any indication of defensive aggregators being involved.

Recommended next steps

For a defendant facing assertion of this patent, it is important to understand that all claims (1-17) remain active and were not invalidated in IPR2026-00102. The institution decision is available on the USPTO PTAB Decisions portal. While the decision indicates that the specific arguments presented by LiftWerx USA Inc. were not persuasive enough for institution, a new IPR could potentially be filed by a different petitioner (or the same petitioner with different arguments if not estopped) relying on new prior art or a more compelling analysis of the existing art. A thorough prior art search beyond the references cited in IPR2026-00102 would be advisable to identify new grounds for potential invalidity challenges.

Inventors

• Per E. Fenger (Liftra IP ApS)

Original assignee

The original assignee is Liftra IP ApS. Liftra IP ApS is an operating company that provides lifting and transport solutions for the wind industry, including tools for installation and maintenance of wind turbines. Their current status is active and operating.

Assignment timeline

• 2024-02-20 (executed) / recorded 2024-02-20 — Reel 066501/0453
  • Conveyance: ASSIGNMENT OF ASSIGNORS INTEREST
  • Assignor: FENGER, PER E.
  • Assignee: LIFTRA IP APS
  • Correspondent: R. Neil Sudol, Coleman & Sudol, LLP, 708 Third Avenue, 14th Floor, New York, NY 10017. This correspondent has not recurred in this chain.
  • Context: Internal transfer from inventor to company.

Timeline diagram

timeline
    title Ownership of US 12104578
    2014 : Priority date
    2024 : Filed by Liftra IP ApS
         : Assigned to Liftra IP ApS
    2024 : Issued to Liftra IP ApS

NPE / troll-pattern signals

1. Shell-entity transfer — not present. The sole recorded assignment is from the individual inventor to an operating company, Liftra IP ApS, which designs and manufactures equipment for the wind energy sector.
2. Known asserter in the chain — not present. Liftra IP ApS is not identified as a known NPE.
3. Repeat correspondent across the chain — not present. The correspondent, R. Neil Sudol of Coleman & Sudol, LLP, appears only once in this patent's assignment record.
4. Cascading transfers — not present. There is only one assignment recorded for this patent.
5. Pre-litigation transfer — unclear. While there is litigation associated with the patent family (IPR2026-00102 and a US case filed in Virginia Eastern District Court), the assignment to Liftra IP ApS (executed and recorded 2024-02-20) precedes the publication date of the patent (2024-10-01) and does not immediately precede the litigation dates currently known (2025 and 2026).
6. Bankruptcy fire-sale — not present. No indication of bankruptcy for the assignor or assignee.
7. Privateering — not present. No evidence in the public record of such an arrangement.
8. Defensive aggregator (anti-NPE) — not present. The patent is currently assigned to Liftra IP ApS, an operating company, not a defensive aggregator.

Verdict

Insufficient data. The only recorded assignment is from the individual inventor to Liftra IP ApS, which is an operating company that manufactures products related to the patent. There are no other assignments or strong signals of NPE activity in the provided records. The existence of litigation (IPR2026-00102 and a US case in Virginia Eastern District Court) on the patent family does not, by itself, indicate an NPE, as operating companies also assert their patents.

USPTO Assignment Center search: https://assignmentcenter.uspto.gov/ (search for patent number 12104578)

Here's an analysis of the most relevant prior art for US Patent 12104578, based on the citations provided within the patent text.

Most Relevant Prior Art

The patent itself identifies German Patent Application DE 102006013539 A1 as particularly relevant.

1. German Patent Application DE 102006013539 A1

• Full Citation: DE102006013539A1, Nordex Energy Gmbh, "Rotor shaft support for wind powered generator has support frame to hold the shaft for access to the bearing and gearbox"
• Publication/Filing Date: Priority date: 2006-03-24, Publication date: 2007-09-27
• Brief Description: This patent discloses a rotor shaft support (main shaft fixture) for a wind turbine generator. It features a support frame designed to hold the main shaft, enabling access for servicing the bearing and gearbox. The fixture is divided into multiple sections for installation on stable structural parts within the wind turbine nacelle, including the bottom frame.
• Potential Anticipation (35 U.S.C. § 102): DE102006013539A1 directly anticipates the introductory clause of independent Claims 1, 15, and 16 of US12104578, which describes a "Main shaft fixture for fixation of a main shaft on a wind turbine during execution of installation and repair work on heavy parts of a wind turbine, where the fixture is divided up into a number of sections for mounting on stable structural parts in a nacelle of a wind turbine, including a bottom frame of the nacelle". The distinguishing features of US12104578's independent claims (e.g., adjustable pressure mandrels with tap shoes, displaceable between passive/active positions, and mounting facilities for a crane, or a specific rotor lock structure) appear to be the inventive aspects over DE102006013539A1.

Other Cited Prior Art

Below are other patent citations from US12104578, with their details and potential anticipations. Due to the high number of citations, this section will focus on those whose titles suggest a direct relevance to key elements of US12104578's independent claims (Claims 1, 13, 15, 16).

2. US 7759815 B2

• Full Citation: US7759815B2, Nordex Energy Gmbh, "Wind motor with a holding device for a rotor shaft"
• Publication/Filing Date: Priority date: 2004-12-17, Publication date: 2010-07-20
• Brief Description: This patent describes a wind motor equipped with a holding device for its rotor shaft, likely for maintenance or assembly purposes.
• Potential Anticipation (35 U.S.C. § 102): Similar to DE102006013539A1, this patent likely anticipates the general concept of a main shaft fixture or holding device for a wind turbine's rotor shaft for maintenance. It could potentially anticipate the broad scope of the pre-characterizing clauses of Claims 1, 15, and 16, regarding a fixture for fixing a main shaft during installation/repair.

3. EP 1101934 A2

• Full Citation: EP1101934A2, Enron Wind GmbH, "Wind turbine having a movable crane in the nacelle"
• Publication/Filing Date: Priority date: 1999-11-18, Publication date: 2001-05-23
• Brief Description: This patent describes a wind turbine that includes a movable crane located within its nacelle.
• Potential Anticipation (35 U.S.C. § 102): This patent is relevant to the "mounting facilities adapted for anchoring a crane on/in a nacelle of a wind turbine" aspect of Claims 1, 13, 15, and 16. It suggests that the concept of having a crane (or facilities for one) within the nacelle for wind turbine work is known.

4. US 20100021278 A1

• Full Citation: US20100021278A1, Ge Wind Energy Gmbh, "Portable crane system for wind turbine components"
• Publication/Filing Date: Priority date: 2008-07-24, Publication date: 2010-01-28
• Brief Description: This patent describes a portable crane system specifically designed for handling components within wind turbines.
• Potential Anticipation (35 U.S.C. § 102): Similar to EP1101934A2, this patent anticipates the idea of having crane systems for wind turbine components, further reinforcing that the "mounting facilities adapted for anchoring a crane" element of Claims 1, 13, 15, and 16 may be a known component or system in the prior art.

5. US 20120217089 A1

• Full Citation: US20120217089A1, Liftra Aps, "Device for establishing admittance and transport of cargo to and from a wind turbine construction above ground level"
• Publication/Filing Date: Priority date: 2009-10-28, Publication date: 2012-08-30
• Brief Description: This patent describes a device for facilitating access and transport of cargo to and from a wind turbine at elevated heights.
• Potential Anticipation (35 U.S.C. § 102): While not directly about a main shaft fixture, this patent by the same original assignee (Liftra Aps) indicates prior art related to handling and transporting components in wind turbines, which is contextually relevant to the overall purpose of US121045578. The general concept of facilities for handling heavy components is broadly known.

6. US 10378518 B2

• Full Citation: US10378518B2, Liftra Ip Aps, "Main shaft fixture"
• Publication/Filing Date: Priority date: 2014-10-07, Publication date: 2019-08-13
• Brief Description: This patent, by the same assignee and sharing the same priority date (2014-10-07) as US12104578, also describes a "Main shaft fixture". Given the shared priority and title, it is highly likely to be a related family member or an earlier issued patent with significant overlap.
• Potential Anticipation (35 U.S.C. § 102): As a family member with the same priority date, this patent likely covers very similar or identical subject matter. If it was published before the critical date for US12104578 (which it was, 2019-08-13 vs. 2024-01-24 filing of US12104578), it could potentially anticipate many or all claims of US12104578, depending on the specific claim differences between the two patents and if it is indeed prior art under 35 U.S.C. § 102(a)(1) or (2). The description of US12104578 states it is a "Continuation of U.S. application Ser. No. 16/452,617, filed Jun. 26, 2019, which is a Divisional of U.S. patent application Ser. No. 15/517,288 filed Apr. 6, 2017, which is a 371 of International Patent Application No. PCT/DK2015/000040 filed Oct. 6, 2015, which claims the benefit of priority to Denmark Patent Application No. PA 2015 00527 filed Sep. 4, 2015, and to Denmark Patent Application No. PA 2014 00573 filed Oct. 7, 2014". US10378518B2 is the granted patent from US15/517,288. Therefore, US10378518B2 would not be prior art in a §102 sense against US12104578, as both share the same priority date and are part of the same patent family, meaning US12104578 can claim priority back to the same earlier applications.

The remaining citations, such as chucks, workholders, or general methods for repairing components, are less directly focused on the specific combination of features claimed in US12104578 for a wind turbine main shaft fixture. They may provide background art for individual components or general mechanical principles, but are less likely to anticipate the specific claims in their entirety.

To analyze the obviousness of US patent 12104578 under 35 U.S.C. § 103, we need to identify combinations of prior art references that would render the claims obvious and explain the motivation for combining them. The patent itself identifies one prior art reference: German Patent Application DE 102006013539 A1.

Prior Art Reference:

• German Patent Application DE 102006013539 A1 (NORDEX ENERGY GMBH): This patent discloses a main shaft fixture for fixing a wind turbine's main shaft during installation and repair work on heavy parts in the nacelle. The fixture is divided into sections for installation on stable structural parts of the nacelle, including the bottom frame.

Analysis of Obviousness under 35 U.S.C. § 103:

A claim is obvious if "the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art." (MPEP § 2141).

Claim 1 Analysis:

Claim 1 describes a main shaft fixture with:

1. A division into a number of sections for mounting on stable structural parts in a nacelle, including a bottom frame.
2. Adjustable pressure mandrels with tap shoes, displaceable between a passive (withdrawn) and an active (engaged) position.
3. Mounting facilities adapted for anchoring a crane on/in the nacelle.

• DE 102006013539 A1 clearly teaches the first element: a main shaft fixture divided into sections for installation on stable structural parts of a nacelle, including the bottom frame. The explicit mention of DE 102006013539 A1 in the background of US12104578 confirms this.

• The key distinguishing features of Claim 1 over DE 102006013539 A1, as suggested by the US12104578 patent itself, are the "adjustable pressure mandrels with tap shoes, and said pressure mandrels being displaceable between a passive, withdrawn lockable position... and an advanced lockable position..." and the "mounting facilities suitable for a lightweight crane."

A person having ordinary skill in the art (POSITA) in wind turbine maintenance and installation would be motivated to combine the teachings of DE 102006013539 A1 with known mechanical fastening and lifting solutions.

• Adjustable Pressure Mandrels with Tap Shoes: The concept of using adjustable pressure mechanisms (like mandrels with tap shoes) to secure a shaft is a well-known mechanical engineering principle, commonly found in chucks, vises, and other clamping devices (e.g., US1853255A, US3494230A, US4623157A, US5015003A, US20020092395A1). A POSITA, facing the "inflexibility in relation to shaft geometry" and the need for a more "universal application" as described in the background of US12104578, would be motivated to replace or augment the existing fixing means in DE 102006013539 A1 with adjustable pressure mandrels and tap shoes. This modification would allow the fixture to accommodate main shafts of different geometries (cylindrical or conical) and diameters, addressing a stated problem in the art. The displaceable nature between passive and active positions is inherent in such adjustable clamping mechanisms.

• Mounting Facilities for a Crane: The need for cranes during wind turbine installation and repair, especially in the nacelle, is well-established in the prior art (e.g., EP1101934A2, US20100021278A1, US20120217089A1). Given that the main shaft fixture (from DE 102006013539 A1) is already installed on stable structural parts of the nacelle, it would be obvious to a POSITA to integrate mounting facilities for a crane directly onto this robust structure. This would streamline operations, save space, and potentially utilize the same anchoring points, as explicitly mentioned as an "advance" in US12104578. Liftra, the assignee, itself focuses on lifting and transportation solutions for the wind industry, highlighting the common knowledge and need for such systems.

Combination 1: DE 102006013539 A1 + General Knowledge of Adjustable Clamping Mechanisms

A POSITA would be motivated to combine the main shaft fixture of DE 102006013539 A1 with adjustable pressure mandrels and tap shoes from general mechanical knowledge of clamping devices. The motivation would be to overcome the limitation of inflexible shaft geometry in existing fixtures, allowing a single fixture to be used for various main shaft designs (cylindrical or conical) and diameters, as articulated in the problem statement of US12104578. This combination directly addresses the stated problem of needing "nearly just as many different fixtures... as there are shaft geometries that exist."

Combination 2: DE 102006013539 A1 + General Knowledge of Crane Mounting in Nacelles

A POSITA would be motivated to combine the nacelle-mounted main shaft fixture of DE 102006013539 A1 with known methods of mounting cranes (e.g., lightweight cranes, self-hoisting cranes) in wind turbine nacelles. The motivation would be to enhance the functionality and efficiency of installation and repair work by providing integrated lifting capabilities, reducing separate setup steps and optimizing space within the nacelle. This directly aligns with the objective of US12104578 to "provide a main shaft fixture that in addition offers facilities for the mounting of a self-hoisting crane, with a ground-based winch" and "ensuring easy and rapid establishment of the self-hoisting crane."

Claim 13 Analysis:

Claim 13 describes an assembly comprising a main shaft fixture according to Claim 1, where a crane is mounted to the main shaft fixture via its mounting facilities.

The obviousness of Claim 13 follows directly from the obviousness of Claim 1. If Claim 1, which includes the mounting facilities for a crane, is considered obvious, then the act of actually mounting a crane onto those facilities to form an assembly would also be obvious to a POSITA. The purpose of having mounting facilities is precisely to mount a crane.

Claim 15 Analysis:

Claim 15 is similar to Claim 1 but specifies that the adjustable pressure mandrels consist of threaded bolts that cooperate with threaded holes.

• As discussed for Claim 1, the use of adjustable pressure mandrels with tap shoes to fix a shaft is a known mechanical concept. The specific embodiment of using "threaded bolts whose opposing free ends facing the main shaft are furnished with tap shoes, and the threaded bolts cooperates with threaded holes" is a very common and basic mechanical means for achieving adjustable linear displacement and clamping force. This method of manual adjustment and retention is a fundamental engineering solution for applying pressure, as acknowledged in US12104578 itself: "The pressure mandrels with the tap shoes are hereby displaced by manual turning of the threaded bolts between the passive position and the active position." A POSITA would readily understand and implement this straightforward mechanical design to achieve the desired adjustability in the context of the main shaft fixture disclosed in DE 102006013539 A1.

Combination 3: DE 102006013539 A1 + General Knowledge of Threaded Fasteners for Adjustable Clamping

A POSITA would be motivated to combine the main shaft fixture of DE 102006013539 A1 with adjustable clamping mechanisms using threaded bolts and threaded holes. The motivation would be to provide a simple, robust, and manually operable means for adjusting and engaging the "tap shoes" against the main shaft, thereby enabling the fixture to accommodate different shaft geometries as required.

Claim 16 Analysis:

Claim 16 is similar to Claim 1 but further comprises a rotor lock, specifically described as a flange element matching the rotor's bolt circle geometry, attached to two parallel beam-shaped brackets that pivotally mount on other brackets anchored to the nacelle's bottom frame.

• Rotor Lock: The need for a rotor lock to fix the wind turbine rotor, especially during maintenance, is explicitly mentioned in the background art of US12104578 as a conventional practice: "Up to now it has been necessary to halt the turbine, i.e., brake it and fix the rotor with a rotor lock...". Therefore, the general concept of incorporating a rotor lock into a main shaft fixture is known in the art.
• The specific structure of the rotor lock (flange element, bolt circle geometry, beam-shaped brackets, pivotal mounting, anchoring to the bottom frame) describes a mechanical arrangement for securing the rotor. Given the overall context of securing the main shaft and providing a stable platform for maintenance, a POSITA would find it obvious to integrate a rotor lock, using known mechanical elements and attachment methods, into the main shaft fixture described in DE 102006013539 A1. The motivation is to ensure the stability of the entire system during heavy maintenance, as a fixed rotor is often a prerequisite for such operations.

Combination 4: DE 102006013539 A1 + General Knowledge of Rotor Locking Mechanisms

A POSITA would be motivated to combine the main shaft fixture of DE 102006013539 A1 with a rotor lock. The motivation would be to provide complete stability to the wind turbine's drivetrain during installation and repair, as the need to "fix the rotor with a rotor lock" is a recognized step in wind turbine maintenance. The specific design details of the rotor lock in Claim 16 (flange, bolt circle, beam-shaped brackets, pivotal mounting) would be considered conventional engineering choices for achieving such a locking function in a nacelle environment, given the need to interface with the rotor and anchor to the nacelle structure.

Overall Conclusion:

While US12104578 presents a comprehensive main shaft fixture, the individual elements and their combination appear to be obvious when considering the prior art (specifically DE 102006013539 A1) and the general knowledge of a person having ordinary skill in the art in mechanical fastening, lifting, and wind turbine maintenance. The motivation to combine these elements arises from clearly identified problems in the prior art, such as the inflexibility of fixtures to different shaft geometries and the need for integrated crane facilities and rotor locking during complex maintenance operations.