Injection-Molded Transport Case With Interlocking Ribs

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Solution Overview

Problem

Transport boxes, such as bottle crates, face challenges in achieving a high stacking load without deformation while maintaining aesthetic appeal and ergonomic handling, as existing designs often compromise on material distribution and structural integrity.

Innovation Solution

A transport box design featuring a base shell and cover shell with interlocking, tooth-like elevations that form a load-bearing skeleton, allowing for high stacking capacity without material accumulation, achieved through a two-stage injection molding process using different plastic materials for enhanced strength and grip comfort.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a two-shell design with different plastics is used to improve ergonomic handling and aesthetic appearance, then grip comfort and visual appeal are improved, but structural integrity and load-bearing capacity deteriorate due to material distribution issues

Engineering Contradiction:
Improvegrip comfortVSAvoidload-bearing capacity
Core Design Contradiction:
Ease of operationVSStrength

Solution Approach 1:

The patent applies different plastic materials to different regions of the transport box: a first plastic material with higher strength and stiffness for load-bearing areas (base and side walls), and a second plastic material with better grip properties for handle areas. This local differentiation resolves the contradiction by optimizing each region's material properties for its specific function.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent uses a composite structure combining two different plastic materials in a two-shell design. The first shell provides structural integrity with load-bearing plastic, while the second shell adds ergonomic grip surfaces. This composite approach allows simultaneous achievement of strength and ease of operation.

Inventive Principle:
Principle #40Composite materials

2Strength

If material is added to reinforcement areas to improve load-bearing capacity, then stacking strength is improved, but material accumulation occurs that negatively influences surface quality and aesthetics

Engineering Contradiction:
Improvestacking load capacityVSAvoidsurface quality
Core Design Contradiction:
StrengthVSShape

Solution Approach 1:

Instead of adding material in the third dimension (creating protruding reinforcements), the patent uses rib-like structures that distribute reinforcement within the wall thickness dimension. This maintains the external surface smoothness while providing internal structural support through the multi-shell construction with interlocking ribs.

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

Solution Approach 2:

The patent employs thin-walled multi-shell construction where the strength comes from the multi-layered structure and interlocking rib patterns rather than thick material accumulations. This allows high stacking load capacity while maintaining smooth external surfaces for aesthetic quality.

Inventive Principle:
Principle #30Flexible shells and thin films

3Strength

If a multi-shell design with interlocking ribs is used to improve structural strength, then load-bearing capacity is improved, but manufacturing complexity increases

Engineering Contradiction:
Improvestructural integrityVSAvoidmanufacturing process complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The patent incorporates the reinforcement ribs and interlocking features directly into the molding process itself, rather than adding them as separate post-manufacturing steps. The multi-shell structure with interlocking ribs is formed in one integrated injection molding operation, which maintains manufacturing efficiency while achieving high structural integrity.

Inventive Principle:
Principle #10Preliminary action

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 design provides a high load-bearing capacity, torsion resistance, and material efficiency while maintaining the ergonomic and aesthetic features, ensuring the transport box can handle stacking forces effectively without deformation or bulging.

Implementation Method 1

the first plastic material is thermally bonded to the second plastic material

Methodology Applied
Scientific EffectThermal bonding: Heating

Data Source

PatentEP1880948B1Transport case and injection moulding device for manufacturing such a transport case
Publication Date: 2010.05.26 HAIDLMAIR HLDG
  • EP1880948B1 patent drawingFigure 1~2
  • EP1880948B1 patent drawingFigure 3~4
  • EP1880948B1 patent drawingFigure 5~6

AI summary

Injection-molded drinks crate is made up of an inner shell (14) with compartments for the bottles and an outer shell. These are connected at the corners (11) by integral interlocking ribs (30). The corners are rounded and their radius of curvature varies with height.