Composite Fastener Locking Cap With Helical Insert Torque Stability

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing locking fasteners, particularly those using resilient inserts like Vespel™, are expensive, difficult to install, prone to damage, and have limited reuse and torque consistency, especially under varying temperature and vibration conditions, and they are costly and labor-intensive to maintain.

Innovation Solution

A new type of nut featuring a helical thread insert and a Lockone clasp with retainers, which provides a positive locking mechanism that increases the strength and consistency of torque performance over traditional fasteners, allowing for reusable and durable fasteners with improved assembly and maintenance processes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If resilient inserts like Vespel™ are used in locking fasteners, then locking capability is achieved, but cost increases and installation becomes difficult

Engineering Contradiction:

Improvelocking capabilityVSAvoidinstallation difficulty

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent replaces expensive resilient inserts with a disposable deformed nut that provides locking capability through controlled deformation. The deformed nut is designed to be installed once and discarded after its locking function is fulfilled, eliminating the need for costly resilient materials while maintaining effective locking.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The invention extracts the locking function from the resilient insert and transfers it to a dedicated deformed nut component. This separation allows the locking mechanism to be implemented through simple deformation of the nut rather than requiring complex resilient material properties, simplifying installation and reducing cost.

Inventive Principle:

Principle #2Taking out (Extraction)

2Reliability

If resilient inserts are used in locking fasteners, then locking is achieved, but the inserts are easily damaged during installation

Engineering Contradiction:

Improvelocking functionVSAvoiddamage resistance

Core Design Contradiction:

ReliabilityVSStrength

Solution Approach 1:

The deformed nut is designed as a disposable component that absorbs installation damages without compromising the locking function. Since it is meant to be discarded after use, it can be made from simpler, more damage-tolerant materials rather than expensive resilient inserts that must maintain their properties through multiple cycles.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The deformed nut incorporates pre-designed deformation zones that absorb installation shocks and damages before they can propagate to critical locking elements. The controlled deformation acts as a cushioning mechanism that protects the essential locking features from damage during the installation process.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

3Reliability

If resilient inserts are used, then locking capability is provided, but reuse and reinstallation are limited

Engineering Contradiction:

Improvelocking capabilityVSAvoidreusability

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The system uses inexpensive deformed nuts that are discarded after single use, eliminating the need for them to be reusable. The locking capability is transferred to the permanent threaded insert that can be reused, while the disposable nut provides the locking function during installation and is then discarded, simplifying the design requirements.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The fastening system is segmented into a reusable threaded insert and a disposable deformed nut. This segmentation allows the expensive, precision-threaded insert to be reused multiple times while the simpler, cheaper nut is discarded after providing its locking function, optimizing both reusability and cost-effectiveness.

Inventive Principle:

Principle #1Segmentation

4Reliability

If resilient inserts are used, then locking is achieved, but torque consistency varies between early cycles and final replacement

Engineering Contradiction:

Improvelocking functionVSAvoidtorque consistency

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The deformed nut provides consistent locking torque through controlled deformation geometry rather than relying on resilient material properties that change over time. The rigid deformation structure maintains consistent torque characteristics from first to last cycle, eliminating the torque drift problem associated with resilient inserts.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The invention changes the locking mechanism from relying on material elasticity (which degrades over cycles) to relying on controlled geometric deformation. This parameter change from material-property-based locking to geometry-based locking ensures consistent torque performance throughout the fastener's service life.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS11209041B2Composite fastener with locking cap feature

Publication Date: 2021.12.28 BPC LG 2 LLC

AI summary

A fastener comprising a nut body and an associated Lockone clasp is disclosed. The locking clasp may be maintained in its association by one or more locking clasp retainers, the retainers forming an arc. In one embodiment, the nut body is formed with an internally threaded thread bore partially filled by helical thread insert. In another preferred embodiment the helical thread insert is a free running helically wound wire thread insert.