Multipurpose Ladder Brackets for Weight Reduction
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Solution Overview
Problem
Existing multipurpose ladders are either too heavy or fail to support loads when used, as they lack sufficient strength and weight distribution to meet safety standards, particularly for ANSI duty ratings of IA and IAA.
Innovation Solution
A lighter weight multipurpose ladder design with thinner rails and strategically positioned brackets to enhance bending strength, optimized for weight savings while maintaining safety and compliance with ANSI standards, incorporating features like articulated hinges, reinforced plates, and optimized rail and rung structures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If traditional multipurpose ladder designs are used, then strength and load support are adequate, but weight is excessive
Solution Approach 1:
The patent applies local quality by positioning brackets at specific locations on the rails where bending forces are highest during cantilever loading. Instead of uniformly strengthening the entire rail structure, brackets are strategically placed at critical stress points (typically one-third to one-half the rail length from the support end), providing localized reinforcement exactly where needed to maintain strength while minimizing overall weight.
Solution Approach 2:
The patent employs composite construction by combining different structural elements (rails, brackets, rungs) made from materials optimized for their specific functions. The brackets and rails are designed as composite structures that leverage the mechanical properties of each component to achieve high strength-to-weight ratio, allowing the ladder to meet load requirements with reduced overall weight.
2Weight of moving object
If rail thickness is reduced to decrease weight, then weight-to-length ratio improves, but bending strength decreases
Solution Approach 1:
The patent addresses this contradiction by making the rails thinner overall but adding localized reinforcement through brackets at critical bending locations. The brackets compensate for the reduced rail thickness by providing additional structural support at the points of highest stress, allowing the rails to be lighter while maintaining adequate bending strength under ANSI test loads.
Solution Approach 2:
The brackets serve as intermediary elements between the thin rails and the applied loads. These brackets transfer and distribute the bending forces from the rungs to the main rail structure, preventing stress concentration that would occur in thin rails without reinforcement, thereby enabling the use of thinner, lighter rails while maintaining structural integrity.
3Strength
If brackets are added to reinforce rails, then bending strength increases, but device complexity increases
Solution Approach 1:
The patent applies segmentation by dividing the reinforcement function into separate, modular bracket components rather than creating a single complex reinforced rail design. Each bracket is an independent element that can be manufactured separately and attached to the rails at specific locations, simplifying the manufacturing process and assembly while achieving the required structural strength.
Solution Approach 2:
The brackets are designed as universal components that serve multiple functions: they reinforce the rails against bending, provide attachment points for rungs, and distribute loads across the rail structure. This multi-functionality reduces the need for additional specialized components, thereby limiting the increase in device complexity while achieving the desired strength enhancement.
Data Source
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AI summary
A multipurpose ladder having a first inner section. The ladder has a first articulated hinge and a second articulated hinge. The ladder has a second inner section. The ladder has a first outer section. The ladder has a first locking bar. The ladder has a second outer section. The multipurpose ladder may have a plurality of brackets disposed about outer rails of the outer sections. The brackets provide support to each of the outer rails and strengthens them against bending forces so the rails can be thinner and of lighter weight. The ladder may have an ANSI duty rating of 1A or an ANSI duty rating of 1AA. A method for using a multipurpose ladder. A method for producing a multipurpose ladder.