Load Hook Latch and Cam Release Against Accidental Opening

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Solution Overview

Problem

Existing load suspension devices for helicopters face issues with accidental opening due to weight-induced stress and inadequate torque reduction, leading to safety concerns during transportation.

Innovation Solution

A load suspension device with a pivotally mounted hook, a locking mechanism featuring a pivoting latch, rollers, and a locking cam that allows controlled release through a lever and cam interaction, providing redundant unlocking mechanisms for enhanced safety.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a locking mechanism based on bearings is used to maintain the hook in the closed position, then the hook can be locked securely, but the mechanism is easily overcome by the weight of the charges raised causing accidental opening

Engineering Contradiction:
Improvelocking securityVSAvoidresistance to weight-induced stress
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent employs a dynamic locking mechanism where a cam rotates to move a lever between locked and unlocked positions. This dynamic system allows the locking state to be actively controlled and changed, rather than relying on passive bearing-based locking that can be overcome by weight. The cam-actuated lever system provides a mechanical advantage that maintains secure locking under load while enabling controlled release.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent replaces the bearing-based mechanical locking system with a cam-actuated lever system. This substitution introduces a rotational cam mechanism that provides more reliable locking by using the cam profile to control the lever position, preventing accidental opening under weight-induced stress while maintaining the ability to release when needed.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Device complexity

If a locking mechanism with low torque reduction is used, then the structure can be simpler, but the effort required to open the hook remains high

Engineering Contradiction:
Improvemechanism structureVSAvoideffort to open hook
Core Design Contradiction:
Device complexityVSEase of operation

Solution Approach 1:

The patent employs a cam with a curved profile that provides mechanical advantage during rotation. The cam's curved surface interacts with the lever to amplify the rotational motion and reduce the torque required to actuate the locking mechanism. This curvature-based mechanical advantage allows for simpler structure while significantly reducing the effort needed to open the hook compared to straight-line actuation mechanisms.

Inventive Principle:
Principle #14Spheroidality (Curvature)

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 effectively prevents unwanted opening of the hook during flight, ensuring secure load transport by reducing the risk of accidental release and allowing for controlled release mechanisms, thereby enhancing air safety.

Implementation Method 1

the lock comprises an upper cavity in which can rest and roll the first roller

Methodology Applied
Scientific EffectRolling: Roller

Implementation Method 2

the locking cam is provided with at least one locking arm which can rest on and roll the second roller

Methodology Applied
Scientific EffectRolling: Roller

Implementation Method 3

a pivoting of the lock under the hook to effect the release of the end of said hook of the lower cavity of said latch

Methodology Applied
Scientific EffectGravity: Gravitation

Data Source

PatentEP3752444B1Load-bearing device for a lifting apparatus
Publication Date: 2021.12.29 LACE
  • EP3752444B1 patent drawingFigure 1a~1b
  • EP3752444B1 patent drawingFigure 2~4
  • EP3752444B1 patent drawingFigure 5~8

AI summary

The invention relates to a bearing device comprising a hook (10), a housing, and a latch and release mechanism for locking and unlocking the hook, the lock and release mechanism having a pivot latch (41) provided with a lower cavity (411) which is capable of receiving one end (111) of the hook, a lever (42) and a locking cam (43). The lever is pivotally mounted in the housing and has a first roller (421) and a second roller (422) on the ends thereof, the latch has an upper cavity (412) in which the first roller can rest and roll, the locking cam is provided with at least one locking arm (431a) on which the second roller can rest and roll, and a rotation of the locking cam in one direction causes the lever to tilt in the other direction, releasing the first roller from the latch, and causes the latch to pivot under the weight of the hook until the end of the hook is released from the lower cavity in the latch.