Sheet-Metal Fastener Nut Structure for Stronger Lightweight Threads
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Solution Overview
Problem
Existing fastener nuts are heavy due to thick walls, costly to manufacture, and prone to loosening under vibrations, with stamped sheet-metal nuts offering weak threading and inadequate strength.
Innovation Solution
A fastener nut formed from sheet metal with radially inset side walls and a resilient joining portion, optimizing material distribution for high thread height and strength, and featuring a dome-shaped or ball-cone-shaped joining portion for enhanced torque resistance and ease of use.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If fastener nuts are forged or cold-formed from thick-walled material, then sufficient thread strength and proof load are achieved, but the nuts become relatively heavy and the manufacturing process becomes time-consuming and costly
Solution Approach 1:
The patent applies local quality by varying the wall thickness of the nut body - the regions requiring high strength (thread engagement areas) have greater thickness, while non-critical areas have reduced thickness. This creates a non-uniform thickness distribution that optimizes the strength-to-weight ratio, allowing the nut to achieve sufficient thread strength without the need for uniformly thick walls throughout the entire structure.
Solution Approach 2:
The patent transitions from traditional 3D forged nuts to a 2D sheet metal construction that is then formed into a 3D shape. The sheet metal is radially inset and formed into a polygonal profile with recesses, creating a multi-layered structure where multiple sheets are stacked and bonded. This dimensional approach allows for complex geometry and optimized material distribution without the material waste and time consumption of traditional forging.
2Weight of moving object
If fastener nuts are stamped or pressed from thin sheet metal to reduce weight, then material usage and weight are reduced, but the threading engagement becomes weak and the nuts are prone to loosening under vibrations
Solution Approach 1:
The patent employs composite construction by stacking multiple sheet metal layers and bonding them together with adhesive. This creates a composite structure where the combined thickness of multiple thin sheets equals or exceeds the thickness of a single thick-walled nut, providing sufficient material for strong thread engagement while maintaining the weight advantages of thin-gauge starting material. The composite structure also provides vibration resistance through the bonding between layers.
Solution Approach 2:
The nut construction is segmented into multiple separate sheet metal layers that are individually formed and then assembled together. Each layer can be optimized for specific functions, and the segmented structure allows for better material distribution and reduced weight compared to a monolithic structure, while the assembled configuration provides the necessary strength through the combined thickness and bonding interfaces.
3Reliability
If additional locking features such as locking rings or adhesives are added to prevent loosening, then vibration resistance is improved, but the device complexity and manufacturing cost increase
Solution Approach 1:
The patent merges the locking function directly into the nut body structure itself, eliminating the need for separate locking components. The polygonal profile with radially inset walls and recesses creates an integrated locking mechanism that prevents loosening through friction and mechanical interference with the bolt threads. This integration of the locking function into the primary structure reduces overall device complexity while maintaining vibration resistance.
Solution Approach 2:
The nut structure provides its own locking capability through the geometric configuration of the radially inset walls and recesses, without requiring external locking features. The structure self-regulates to prevent loosening through the interaction between the inset walls and the bolt, creating a self-locking mechanism that simplifies the overall fastener system by eliminating the need for separate locking devices.
Data Source
Figure 1(a)~1(c)
Figure 2
Figure 3(a)~3(d)
AI summary
A fastener nut (100) is provided that is formed from an integral piece of sheet metal having a first axial end and an opposed second axial end along a central axis (112), comprising: an annular head member (102) at said first axial end, comprising a plurality of side walls (108a-108f) defining a substantially polygonal external profile configured to engage with a tool and an internal profile comprising a thread (120) with a thread groove configured to engage with a screw, wherein at least a portion of at least one or more, preferably each one, of said plurality of side walls (108a-108f) is radially inset so as to form radially outward protruding corners (118a-118f) with the radially inset side wall portion (108a-108f) being between two such corners and preferably so as to form a substantially cylindrical internal axial passage (114), preferably concentric with the central axis (112), wherein at least one or more, preferably all of the radially inset side wall portions (108a-108f) comprises a thread groove with a groove deepness equal or greater as compared to the groove deepness of the thread (120) in the area directly adjacent to said radially inset side wall portion; and preferably a flange member (106), extending radially outward from said plurality of side walls (108a-108f) at said second axial end.