Triple-Noose Rope Shackle for Secure Lightweight Load Coupling

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Solution Overview

Problem

Metal shackles are heavy, bulky, and difficult to manually lift and deploy, posing safety risks and storage challenges, while soft shackles with buttons are prone to rope damage and unsafe load disengagement.

Innovation Solution

A shackle design featuring a flexible elongate member with a continuous endless circuit forming three noose portions, allowing for proportional tightening and loosening through a shackle pin, and optionally sheathed with durable materials for enhanced safety and ease of use.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If metal shackles are designed to be strong for heavy load situations, then load-bearing capacity is improved, but weight and bulkiness increase making them difficult to manually lift and deploy

Engineering Contradiction:
Improveload-bearing capacityVSAvoidshackle weight
Core Design Contradiction:
StrengthVSWeight of moving object

Solution Approach 1:

The patent replaces traditional rigid metal shackle construction with a flexible rope-based structure. The rope is configured to pass through itself and form three sequentially adjacent noose portions that collectively provide the structural strength needed for heavy loads while maintaining flexibility and significantly reducing weight compared to metal alternatives.

Inventive Principle:
Principle #30Flexible shells and thin films

2Strength

If metal shackles are designed to be strong for heavy load situations, then load-bearing capacity is improved, but storage difficulty increases due to heavy weight and bulkiness

Engineering Contradiction:
Improveload-bearing capacityVSAvoidstorage ease
Core Design Contradiction:
StrengthVSEase of operation

Solution Approach 1:

The flexible rope construction allows the shackle to be coiled or folded into a compact form for storage, dramatically improving storage ease compared to rigid metal shackles that maintain their bulky shape regardless of storage conditions.

Inventive Principle:
Principle #30Flexible shells and thin films

3Ease of operation

If soft shackles use a button design, then ease of operation is improved, but reliability deteriorates due to rope damage and unsafe load disengagement

Engineering Contradiction:
Improveease of couplingVSAvoidsafety against disengagement
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent employs a dynamic locking mechanism where the rope passes through itself to form three sequentially adjacent noose portions. The intermediate noose portion acts as a self-locking feature that dynamically responds to load forces, preventing accidental disengagement while maintaining ease of operation during proper coupling.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The triple-noose configuration provides inherent redundancy and safety margins before failure can occur. The intermediate noose portion serves as a protective element that prevents direct failure modes present in simpler button designs, cushioning against operational errors or rope damage.

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

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 design provides a lightweight, safer, and more manageable shackle that reduces the risk of catastrophic failure and enhances user safety by preventing accidental disengagement, while maintaining high load-bearing capacity.

Implementation Method 1

a contraction or extension of the intermediate noose portion causes a movement of said length of rope through where the elongate member passes through itself, thereby effecting a proportional tightening or loosening of one or each of said end noose portions

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP4448862B1A shackle
Publication Date: 2026.04.01 RIGGING CONCEPTS LTD
  • EP4448862B1 patent drawingFigure 1
  • EP4448862B1 patent drawingFigure 2A~2B
  • EP4448862B1 patent drawingFigure 3

AI summary

The present invention relates to a shackle (100). The shackle comprises a shackle body (101) for use with a shackle pin (102).The shackle body (101) comprises a flexible elongate member (104) comprising at least one length of rope circuitously formed so that the flexible elongate member (104) passes through itself and defines three sequentially 5 adjacent noose portions Three sequentially adjacent noose portions comprise an intermediate noose portion (110) and two end noose portions (108, 109) at opposing ends of the shackle body (101).