Adjustable Load Hook Return Spring Layout for Reliable Closure
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing load hook return systems in helicopters suffer from premature spring failure due to non-compressive distortion, limited stiffness, exposure to external aggressions, and non-adjustable preload, which compromises the secure closure of the load hook.
Innovation Solution
A return system with adjustable elastic means, comprising tension springs mounted between a housing rod and a crank pin, allowing for adjustable restoring force through a connecting rod and adjustment nut, ensuring the load hook can be securely closed with adjustable pre-tension and enhanced safety via parallel spring mounting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a horizontal return spring is mounted between the housing and the hook at the tilting axis, then the hook can be returned to closed position, but the spring undergoes distortion during operation leading to premature failure
Solution Approach 1:
The patent inverts the conventional spring mounting approach by changing from a horizontal spring arrangement to a vertical arrangement. The spring is mounted between a first element (housing) and a second element (hook) in a vertical orientation, which eliminates the distortion problem that occurs with horizontal mounting during hook tilting operations.
2Reliability
If the spring is mounted horizontally between housing and hook, then the hook return function is achieved, but the spring is exposed to external aggressions when located outside the housing
Solution Approach 1:
The patent applies nesting by placing the spring within the housing structure. The spring is mounted vertically inside the housing between the first element and the second element, protecting it from external aggressions like sand and moisture while maintaining its return function.
3Adaptability or versatility
If a fixed stiffness spring is used, then the hook return system is simple, but the stiffness cannot be adjusted according to mission requirements
Solution Approach 1:
The patent introduces dynamics by making the spring stiffness adjustable. The mounting system allows the spring's effective stiffness to be modified according to mission requirements, transforming a static system into a dynamic one that can adapt to different operational conditions.
4Force
If the spring is mounted to provide maximum closure force, then the hook closes securely, but the spring may fail prematurely due to excessive stress
Solution Approach 1:
The patent applies parameter changes by modifying the spring's mounting orientation and position. The vertical mounting arrangement changes the stress distribution parameters, allowing the spring to provide sufficient closure force while operating under more favorable stress conditions that extend its lifespan.
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 system provides a secure, adjustable, and robust load hook return mechanism that prevents premature spring failure, maintains stiffness, and ensures reliable closure by allowing adjustable pre-tension and parallel spring redundancy.
Implementation Method 1
an elastic means mounted between a rod integral with said housing and a crank pin fixed to the load hook, said return system being capable of exerting a return force on the load hook in order to allow the load hook to be closed
Data Source
AI summary
The present invention relates to a return system (10) intended to equip a hooking device comprising a housing and a load hook (30) mounted so as to be able to pivot relative to the housing, the return system being mounted between a rod (21) secured to said housing, and comprising at least one tension spring (11), a device for adjusting the force of each tension spring with a plate (12) and a connecting rod (13) adjustably attached to the plate, and a crank pin (14) situated at a free end of the connecting rod, each tension spring links the rod to said plate, the crank pin is attached to the load hook, and the return system exerts a return force on the load hook that allows said load hook to close. The present invention also relates to a hooking device equipped with such a return system.