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).