Load-Responsive Cable Rotation Blocking for Hoist Strength

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Solution Overview

Problem

Rotation-resistant cables used in rescue hoists face torque imbalance under high loads, leading to cable rotation and reduced breaking strength, as the torque between inner and outer strands is not perfectly balanced, and existing solutions that block cable ends to maximize strength are not operational under normal conditions.

Innovation Solution

A Cable Rotation Blocking System (CRBS) with two sections that are either rotatable or non-rotatable based on load thresholds, utilizing a bearing holder, shim washer, and spring washers to connect the cable and load, preventing rotation when loads exceed an upper threshold by contacting internal and external surfaces, ensuring even load distribution and maximum breaking strength.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the cable ends are blocked to maximize breaking strength, then the cable strength is improved, but the cable cannot swivel freely under normal operational loads

Engineering Contradiction:
Improvecable breaking strengthVSAvoidcable swiveling capability
Core Design Contradiction:
StrengthVSEase of operation

Solution Approach 1:

The patent applies the dynamics principle by creating a system that automatically transitions between two states based on load conditions: under normal loads, the second section rotates freely about the axis to allow cable swiveling, but when the load exceeds a predetermined threshold, the system engages to prevent rotation and maximize breaking strength. This dynamic state change resolves the contradiction by making the system adaptive to operational conditions rather than fixed in one configuration.

Inventive Principle:
Principle #15Dynamics

2Stability of the object's composition

If rotation-resistant cable construction is used with inner and outer strands wound in opposite directions, then cable rotation is reduced, but torque imbalance under high loads still causes rotation and reduced breaking strength

Engineering Contradiction:
Improvecable rotation resistanceVSAvoidcable breaking strength under high load
Core Design Contradiction:
Stability of the object's compositionVSStrength

Solution Approach 1:

The patent applies preliminary anti-action by implementing a preventive mechanism that engages before torque imbalance can cause harmful rotation. The system includes a predetermined threshold mechanism that detects approaching high-load conditions and preemptively engages the rotation-blocking feature, preventing the torque imbalance from causing cable rotation and strength reduction in the first place, rather than merely responding after rotation has occurred.

Inventive Principle:
Principle #9Preliminary anti-action

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 CRBS significantly enhances cable performance by maintaining maximum strength under ultimate load tests while allowing free swiveling under normal loads, increasing breaking strength by at least 25% compared to conventional systems.

Implementation Method 1

The bearing holder and the bearing shim washer may be fixedly attached to each other so that they cannot move relative to each other. The first section may further comprise means for connecting the cable to the first end of the body, and may further comprise a bearing holder provided internally of the body and a bearing shim washer in contact with the bearing holder.

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3718947B1Cable rotation blocking system
Publication Date: 2021.09.22 GOODRICH CORP
  • EP3718947B1 patent drawingFigure 1a~1b
  • EP3718947B1 patent drawingFigure 2
  • EP3718947B1 patent drawingFigure 3

AI summary

A cable rotation blocking system (CRBS) (300) is described herein. The CRBS extends along an axis X between a first end (305) and a second end (303), and comprises a first section provided at the first end (305), the first section being configured to be connectable to a cable (100). The CRBS further comprises a second section provided at the second end (303), the second section being configured to be attachable to a load. With the CRBS described herein, when no load, or a load up to an upper load threshold is attached to the second section, the second section is rotatable about the axis X, relative to the first section, however, when a load higher than the upper load threshold is attached to the second section, the second section is prevented from rotation about the axis relative to the first section.