Blind Fastener And Method Of Installation Thereof
Patent No. US11885358 (titled "Blind Fastener And Method Of Installation Thereof") was filed by Howmet Aerospace Inc on Feb 7, 2019.
What is this patent about?
’358 is related to the field of mechanical fasteners, specifically blind fasteners used in structures like vehicle frames and storage racks. These fasteners are installed in bores to join elements, and their failure can result from fatigue or bore variations. Designing for blind installation, where access is limited to one side, presents unique engineering challenges.
The underlying idea behind ’358 is to provide a blind fastener with a mandrel and sleeve design that allows for installation without fracturing the mandrel. This is achieved by controlling the axial length of the pull region on the mandrel, ensuring it's no more than four times the diameter of the shank region. This design reduces installation forces and increases corrosion resistance.
The claims of ’358 focus on a blind fastener comprising a sleeve and a mandrel. The mandrel has an enlarged portion at one end and a pull region at the other, connected by a shank region. Crucially, the pull region's length is limited to a maximum of four times the shank diameter, enabling engagement with an installation tool. Claim 16 further details a method of using this fastener, involving insertion, collet engagement, sleeve deformation, and swaging to secure the fastener.
In practice, the fastener is inserted into a bore, and a collet engages the pull region of the mandrel. An anvil then contacts the sleeve end, while the collet pulls the mandrel. This action deforms the sleeve on one side of the structure and swages the sleeve onto the mandrel's shank on the opposite side, creating a secure joint. The controlled length of the pull region allows for this deformation and swaging without requiring the mandrel to fracture.
Unlike traditional blind fasteners that rely on fracturing a breakneck groove on the mandrel, ’358's design eliminates this feature. This allows for lower installation forces, enabling the use of lighter tools and reducing the risk of damage to the structure. The design also allows for a thinner sleeve wall, saving material costs. By avoiding mandrel fracture, the fastener provides a more controlled and predictable installation process, enhancing both the fastener's performance and the installation tool's lifespan.
How does this patent fit in bigger picture?
Technical landscape at the time
In the late 2010s when ’358 was filed, blind fasteners were commonly used in vehicle frames, storage racks, and solar panel sub-structures, at a time when installation typically relied on manual or semi-automated tools to apply force and deform the fastener components.
Novelty and Inventive Step
The claims were rejected in an Office action. The examiner rejected claims 1-20 under 35 U.S.C. 103 as being unpatentable over a prior art reference. The prosecution record does describe the technical reasoning and specific claim changes that led to the rejection.
Claims
This patent contains 20 claims, with independent claims 1 and 16. Claim 1 focuses on the structural components of a blind fastener, while claim 16 focuses on a method for fastening using the same blind fastener. The dependent claims generally elaborate on specific features, materials, and configurations of the fastener and further define steps and parameters of the fastening method.
Key Claim Terms New
Definitions of key terms used in the patent claims.
Patent Family
File Wrapper
The dossier documents provide a comprehensive record of the patent's prosecution history - including filings, correspondence, and decisions made by patent offices - and are crucial for understanding the patent's legal journey and any challenges it may have faced during examination.
Date
Description
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US11885358
- Application Number
- US17423980
- Filing Date
- Feb 7, 2019
- Status
- Granted
- Expiry Date
- Feb 3, 2040
- External Links
- Slate, USPTO, Google Patents