7000 Series Aluminum Ladder Rails That Resist Bend Cracking
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Solution Overview
Problem
Current multipurpose ladders face challenges due to their weight, which makes them difficult to transport and position, and the use of 7000 series aluminum alloy introduces brittleness issues that can lead to stress cracking, particularly at bends in the material.
Innovation Solution
The ladder is constructed using 7000 series aluminum alloy with a specific method involving extrusion, cutting, bending, and age hardening to prevent cracking, and includes articulated hinges and locking mechanisms to enhance mobility and stability, while reducing weight through optimized rail and rung design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If 7000 series aluminum alloy is used to reduce weight, then the ladder becomes lighter and stronger, but the material becomes more brittle and prone to stress cracking
Solution Approach 1:
The patent applies parameter changes by modifying the manufacturing process parameters for 7000 series aluminum alloy, specifically controlling extrusion parameters, bending parameters, and heat treatment parameters to produce rails that are free from stress cracking while maintaining the weight and strength benefits of the alloy
Solution Approach 2:
The patent applies preliminary action by performing bending operations before heat treatment to establish the final rail geometry in a controlled manner, preventing stress cracking from developing during subsequent processing steps
2Strength
If 7000 series aluminum alloy is used to increase strength, then the duty rating increases to at least 300 lbs, but the material brittleness increases making processing more difficult
Solution Approach 1:
The patent applies parameter changes by optimizing extrusion parameters, bending parameters, and heat treatment parameters specifically for 7000 series aluminum alloy to achieve the required strength while avoiding processing difficulties associated with material brittleness
3Ease of manufacture
If traditional ladder design is used, then manufacturing is simpler, but weight is higher making transport and positioning difficult
Solution Approach 1:
The patent applies parameter changes by using 7000 series aluminum alloy with optimized processing parameters to reduce material weight while maintaining structural integrity, and by optimizing the geometric parameters of rails and rungs to minimize weight without sacrificing strength
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 results in a lighter, stronger ladder with a higher duty rating that is easier to transport and position, maintaining performance without suffering from stress cracking issues, as evident in the weight reduction and increased strength compared to 6000 series alloy ladders.
Implementation Method 1
the use of 7000 series alloys come with challenges. One being that with the increased strength also comes with more brittleness
Data Source
AI summary
A ladder and a multipurpose ladder whose rungs and rails are made out of 7000 series aluminum alloy and which has a duty rating of at least 250 lbs. A method for producing a ladder. A method for using a ladder.