Foldable Cart Side Structure Optimization

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Solution Overview

Problem

Existing sheet folding trailers have a high folding height, small capacity, complex side structures, and high costs due to excessive parts, leading to increased folding volume and costs.

Innovation Solution

A novel sheet folding trailer design featuring a vertical skeleton unit with a front-frame and rear-frame component, pocket component, bottom-frame mechanism, wheel component, and handle component, optimized to reduce folding height, increase capacity, and simplify the side structure using fewer parts, with a focus on welding and mesh belt fastening for cost-effectiveness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the side structure uses more parts (4-6 parts) to ensure stability and functionality, then the structural reliability is improved, but the device complexity and manufacturing cost increase

Engineering Contradiction:
Improvestructural reliabilityVSAvoidside structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges multiple side structure parts into a single integrated side structure component. Instead of using 4-6 separate parts as in prior art, the invention integrates these functions into one piece that includes the side frame, support structures, and connection points, thereby reducing complexity while maintaining reliability through unified design

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The simplified side structure component is designed to perform multiple functions simultaneously: providing structural support, enabling folding motion, accommodating the mesh belt, and facilitating connection to other components. This multi-functionality allows a single part to replace multiple specialized parts, reducing overall complexity

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Ease of operation

If the folding height is increased to accommodate the folded state, then the ease of folding is improved, but the folding volume increases reducing storage efficiency

Engineering Contradiction:
Improvefolding easeVSAvoidfolding volume
Core Design Contradiction:
Ease of operationVSVolume of stationary object

Solution Approach 1:

The patent implements a nested folding mechanism where the side structures fold inward and nest within the overall trailer framework. The mesh belt and pocket component are designed to collapse into the confined space between the frame structures, achieving compact folding without requiring excessive height

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The folding mechanism transitions from vertical height reduction to horizontal compression. Instead of folding upward requiring significant height, the structure folds laterally and compresses in the horizontal dimension, allowing the folded state to fit within a smaller overall volume while maintaining ease of operation

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Device complexity

If the number of parts is reduced to simplify structure and reduce cost, then the device complexity is reduced, but the ease of manufacture may be affected

Engineering Contradiction:
Improvenumber of partsVSAvoidmanufacturing ease
Core Design Contradiction:
Device complexityVSEase of manufacture

Solution Approach 1:

While reducing the total number of parts, the patent maintains manufacturing ease by segmenting the single side structure component into modular sections that can be manufactured separately and assembled. This segmentation allows for standardized production of complex shapes while keeping the overall part count low, balancing manufacturing simplicity with structural integration

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent optimizes the geometric parameters and material properties of the side structure component to facilitate manufacturing. By carefully selecting thickness, curvature radii, and connection point locations, the complex integrated shape becomes manufacturable using standard forming and joining processes, ensuring that part reduction does not compromise ease of manufacture

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3988424B1Foldable cart
Publication Date: 2023.04.05 ZHANG XIANGSHAN
  • EP3988424B1 patent drawingFigure 1
  • EP3988424B1 patent drawingFigure 2
  • EP3988424B1 patent drawingFigure 3

AI summary

The invention discloses a novel sheet folding trailer, comprising pocket component, front-frame component, rear-frame component, bottom-frame component, wheel component, handle component, wherein vertical skeleton unit of the invention comprises front-frame component and rear-frame component, the pocket component is arranged between front-frame component and rear-frame component, the bottom-frame component comprises front bottom-frame component, rear bottom-frame component, bottom-frame U-shaped hinge, drive tube component, the wheel component comprises universal wheel fork a, universal wheel fork b, directional wheel fork a, directional wheel fork b, torque tube a, torque tube b, the handle component is arranged at one side of front-frame component, the handle component and the front-frame component are connected through linkage component. Through structural optimization, the invention has a small folding height, a large capacity after opening, and has a simple side structure by adopting only two parts, which effectively reduces the product cost, moreover, the folding height thereof will not change.