Helical Thread Insert Nut for Reusable Positive Locking
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Solution Overview
Problem
Existing locking fasteners, particularly those using resilient inserts like Vespel™, are expensive, difficult to install, and have limitations such as damage during installation, inability to reuse, and shape restrictions, leading to inconsistent torque values and reduced reliability.
Innovation Solution
A new type of nut featuring a helical thread insert and a retained Lockone clasp, which provides a positive locking mechanism and is designed to be reusable, with the helical thread insert increasing the strength of the fastener assembly.
Engineering Contradictions & Design Principles
Engineering 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
Solution Approach 1:
The patent replaces expensive resilient inserts with a disposable deformed nut that provides locking capability through controlled deformation. The nut is designed to be deformed during installation to create the locking effect, eliminating the need for costly resilient materials while maintaining reliability.
Solution Approach 2:
The invention extracts the locking function from the resilient insert and transfers it to the nut itself through controlled deformation. By removing the resilient insert component entirely and embedding the locking mechanism within the nut's deformation characteristics, the system simplifies installation while preserving locking capability.
2Reliability
If resilient inserts are used in locking fasteners, then locking capability is provided, but the inserts are easily damaged during installation and cannot be reused
Solution Approach 1:
The deformed nut is designed as a disposable component that absorbs installation stresses through controlled deformation. Rather than using fragile resilient inserts that can be damaged, the system employs a robust metal nut that can be deformed intentionally to create the locking effect, then discarded after single use, eliminating reuse issues.
3Reliability
If prevailing torque fasteners with resilient inserts are used, then locking is achieved, but torque consistency varies between early cycles and final replacement
Solution Approach 1:
The nut is pre-deformed during manufacturing to specific geometric parameters that ensure consistent torque characteristics. By establishing the deformation geometry in advance rather than during installation, the system achieves uniform torque values across all usage cycles, eliminating variability between early cycles and final replacement.
4Reliability
If locked fasteners with positive locking mechanisms are used, then reliability is improved, but device complexity increases
Solution Approach 1:
The invention merges the locking function with the nut body itself through controlled deformation. Rather than adding separate locking components like clips or pins, the nut's own deformation creates the positive locking effect, integrating multiple functions into a single component and reducing overall system complexity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The new fastener system offers improved strength, consistency in torque performance, and reduced costs compared to traditional systems, with the ability to maintain torque tolerances over multiple cycles and withstand varying temperatures and vibrations.
Implementation Method 1
a helical wire insert that increases the strength of a fastener
Implementation Method 2
a retained cap to lock a fastener in place
Data Source
AI summary
A fastener system including a nut body and a helical thread insert. The nut body having an internally threaded bore containing a plurality of bore threads, and at least one bore obstruction. The helical thread insert formed to create a plurality of internal HTI threads and a plurality of external HTI threads, with the helical thread insert received in the internally threaded bore and not occupying all of the plurality of bore threads, and having its movement limited by the bore obstruction. The helical thread insert having threads with both circular end profiles and a non-circular end profile. The non-circular end profile including at least three straight segments, and located between circular threads.