Double-Locking Safety Hook for Unintentional Opening Prevention

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Solution Overview

Problem

Existing safety hooks fail to reliably retain loads under abnormal conditions due to lock mechanism failures, posing safety hazards from unintentional opening.

Innovation Solution

A hook design featuring a double locking mechanism with a locking element and biasing element that secures the hook arm in a closed position, preventing unintentional opening even under abnormal forces or wear, using a lock securing device to prevent activation of the locking mechanism.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a single locking mechanism is used to secure the hook arm in the closed position, then the hook can function with simpler structure and fewer components, but the reliability of preventing unintentional opening under abnormal forces or wear is reduced

Engineering Contradiction:
Improvereliability of preventing unintentional openingVSAvoidcomplexity of locking mechanism
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The locking mechanism is divided into two independent locking elements (first locking element and second locking element) that can engage with the hook arm simultaneously. This segmentation allows each locking element to provide independent security, so that if one fails due to wear or abnormal forces, the other remains functional to prevent unintentional opening.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The biasing element is configured to bias both locking elements toward the engaged position simultaneously, providing pre-loaded protective force before any failure occurs. This beforehand cushioning ensures that the locking mechanism is already under optimal locking force when the hook is closed, compensating for potential wear or unexpected forces before they can cause failure.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

2Strength

If larger sized hooks with higher mass are used to handle heavier loads, then the load capacity increases, but the kinetic energy transmitted to the lock components under abnormal force conditions increases causing unplanned activation or failure

Engineering Contradiction:
Improveload capacityVSAvoidintegrity of locking mechanism under abnormal forces
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The locking mechanism uses two separate locking elements instead of one, distributing the stress and kinetic energy impact across multiple components. When abnormal forces occur on large hooks, the energy is divided between two locking elements rather than concentrated on one, reducing the likelihood of both failing simultaneously and maintaining reliability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The biasing element provides continuous pre-loading force to both locking elements, creating a state of heightened readiness that counteracts the effects of kinetic energy from abnormal forces. This beforehand cushioning ensures the locking elements remain firmly engaged even when subjected to the higher kinetic energy impacts that occur with larger, heavier hooks.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

3Ease of operation

If the locking mechanism allows free movement for normal operation, then the ease of opening and closing the hook is improved, but wear and tear induces additional play reducing integrity and causing lock failure

Engineering Contradiction:
Improveease of opening and closingVSAvoidintegrity of locking mechanism
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The biasing element continuously applies pre-loading force to keep both locking elements firmly engaged with the hook arm, compensating for wear and play before they can accumulate to dangerous levels. This beforehand cushioning maintains reliable locking pressure even as normal operational wear occurs, preventing the development of excessive play that would lead to failure.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

Using two locking elements provides redundancy against wear-induced play. Even if one locking element develops significant play due to wear, the second locking element remains functional to maintain the closed position, preserving both ease of operation and reliability over extended use.

Inventive Principle:
Principle #1Segmentation

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

Ensures the hook remains securely locked, enhancing user safety and load integrity by preventing accidental release, especially in larger hooks subjected to significant forces.

Implementation Method 1

a biasing element which is configured to bias the locking element towards the engaged position

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3844091B1Double locking hook
Publication Date: 2025.10.15 NAUTILUS HOOKS LTD
  • EP3844091B1 patent drawingFigure 1
  • EP3844091B1 patent drawingFigure 2
  • EP3844091B1 patent drawingFigure 3~4

AI summary

A lockable safety hook such as used for lifting loads and the like wherein the locking mechanism features a double locking function by way of a lock securing device arranged to prevent movement or unintentional activation of the locking mechanism by "locking the lock".