One-Piece Composite Ladder Rung for Lower Weight and Stable Assembly
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current ladder rung technologies, particularly aluminum forming applications, are limited in achieving a balance of safety, weight, and ease of movement, as they often require multiple parts and complex assembly processes, which can lead to instability and increased weight.
Innovation Solution
A one-piece composite rung made of carbon fiber or glass, at least 12 inches long and weighing no more than 0.35 pounds, is riveted to fiberglass rails without penetrating them, using a method that involves placing carbon fibers in molds, autoclaving, and using steel rivets for attachment, resulting in a lightweight and stable design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If traditional aluminum rungs with multiple parts (swaged joint or beaded assembly) are used, then structural strength is achieved, but weight increases and assembly complexity increases
Solution Approach 1:
The patent combines multiple traditional aluminum components (rung body, plates, and ferrules) into a single integrated composite rung made of carbon fiber or glass fiber reinforced polymer. This merging eliminates the need for separate parts and complex swaging operations, reducing overall weight while maintaining structural strength through the high strength-to-weight ratio of composite materials.
Solution Approach 2:
The invention uses composite materials (carbon fiber or glass fiber reinforced polymer) to replace traditional aluminum alloy. These composite materials provide superior strength-to-weight ratio, allowing the rung to achieve comparable or superior structural strength while significantly reducing weight (to 0.35 pounds or less for rungs 12 inches or longer).
2Strength
If multiple parts are assembled to form the rung, then structural integrity is achieved, but manufacturing complexity increases
Solution Approach 1:
The patent integrates the rung body, attachment plates, and ferrules into a single molded composite component. This eliminates multiple assembly steps (swaging, fastening, or bolting of separate parts) and simplifies manufacturing to primarily the molding process itself, followed by direct riveting to the ladder rails.
Solution Approach 2:
The composite rung is pre-formed with integrated attachment features (flat faces and flared ends) during the molding process. These features are built-in beforehand to receive rivets and attach to the rails, eliminating the need for post-assembly operations to create attachment points or join multiple components.
3Stability of the object's composition
If the rung is made solid and heavy, then stability is improved, but ease of movement decreases
Solution Approach 1:
The use of carbon fiber or glass fiber reinforced polymer provides high structural stiffness and strength despite low density. This allows the rung to be made hollow or with optimized internal structure to reduce weight (improving mobility) while maintaining sufficient rigidity and stability for safe ladder operation.
Solution Approach 2:
The composite rung structure can be optimized with varying material distribution - thicker sections at high-stress areas (attachment points, center) and thinner sections elsewhere. This local quality optimization maintains stability where needed while minimizing weight overall, enabling easy ladder movement.
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 provides a lightweight, stable, and safe ladder rung with significant weight savings (approximately 50%) while maintaining structural integrity and ease of movement, utilizing materials like carbon fiber and glass for enhanced strength and resistance properties.
Implementation Method 1
autoclaving, and using steel rivets for attachment
Implementation Method 2
placing carbon fibers in molds, autoclaving
Implementation Method 3
rivets that extend through the faces and the inner face surface of the web of the rails to attach the rung to the first rail and the second rail
Data Source
AI summary
A ladder having a first fiberglass rail. The ladder having a second fiberglass rail. The ladder having a one-piece composite rung which is hollow and made of carbon fiber or glass. The rung has a middle and a first end and a second end. The ladder having rivets that extend through the first end and the second end of the rung to attach the rung to the first rail and the second rail. No portion of the rung penetrates any portion of the first or second rails.