Locking Nut Jaw Mechanism for Anti-Unscrewing Braking

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Solution Overview

Problem

Existing screw fastening devices fail to provide reliable braking against unscrewing due to mechanical excitations, especially in applications requiring precise torque control, and often require complex designs or additional components that can lead to loosening issues and increased weight and size.

Innovation Solution

A screw fastening device with a ring actuating member that rotates to engage a circumferential jaw with a braking surface, allowing for effective braking without damaging threads, using a flexible jaw design that reduces actuation force and incorporates a pressure limiter to protect the assembly, and is designed for simplicity and reliability with minimal weight and size impact.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If braking means are added to screw fastening devices to prevent inadvertent unscrewing, then reliability against mechanical excitations is improved, but device complexity increases

Engineering Contradiction:
Improvereliability against inadvertent unscrewingVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The braking function is merged with the nut body by integrating the jaw directly into the nut structure. The jaw is formed as an integral part of the nut body, eliminating the need for separate braking components and reducing overall device complexity while maintaining reliability against inadvertent unscrewing.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The jaw is designed with elastic properties to automatically engage and disengage based on the screwing/unscrewing motion. During screwing, the jaw elastically deforms to engage the thread and provide braking; during unscrewing, it automatically releases. This self-actuating mechanism eliminates complex actuating systems while ensuring reliable braking when needed.

Inventive Principle:
Principle #25Self-service

2Reliability

If additional braking components are added, then braking capability is improved, but weight and size increase

Engineering Contradiction:
Improvebraking capabilityVSAvoiddevice weight
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

The braking function is integrated into the existing nut structure, adding only the minimal material necessary for the elastic jaw. This eliminates the weight of separate braking components while maintaining braking capability. The jaw is designed with optimized dimensions to provide sufficient braking force with minimal additional mass.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The jaw is designed as a thin elastic structure that flexes during operation. This flexible design provides effective braking capability while minimizing the amount of material required, thereby reducing weight and size compared to rigid braking components.

Inventive Principle:
Principle #30Flexible shells and thin films

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 solution ensures reliable braking after multiple screwing-unscrewing cycles with moderate actuation forces, no risk of component misplacement, and no thread damage, maintaining the device's integrity and safety while minimizing size and weight.

Implementation Method 1

the return of the jaw to the released state taking place by elasticity

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3983688B1Screw-fixing device, with locking in the screwed state
Publication Date: 2023.08.02 JPB SYST
  • EP3983688B1 patent drawingFigure 1~2
  • EP3983688B1 patent drawingFigure 3~4
  • EP3983688B1 patent drawingFigure 5~6

AI summary

The nut comprises locking jaws (14), a floating end of which is actuated by cam profiles inside a rotary actuation ring (19). The jaws are produced by removing material from the body (11) of the nut and shift from the locking state to the release state and vice versa by elastic bending deformation. The locking surface (16) on the inside of the jaws has the same thread as the body of the nut.