Bottom-up Last for Footwear Upper Forming
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Solution Overview
Problem
Current methods for manufacturing footwear lack efficiency in forming the upper structure, particularly in ensuring precise fitting and stability, and often require traditional strobel construction which can complicate the manufacturing process.
Innovation Solution
A method utilizing a last assembly with a base member and a pressing system that applies pressure and heat to shape and bond material sections directly, eliminating the need for a traditional strobel by using vacuum holes and retractable pins for temporary fixation, and a flexible membrane to form a contoured upper structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If traditional strobel construction is used, then the upper structure can be formed with conventional methods, but the manufacturing process becomes complicated and less efficient
Solution Approach 1:
The patent eliminates the traditional strobel layer from the footwear construction by directly bonding the upper material to the sole assembly. This extraction of the intermediate strobel component simplifies the overall construction process and reduces manufacturing steps while maintaining structural integrity.
Solution Approach 2:
The upper formation process is merged directly with the sole assembly bonding process. Instead of separately constructing the upper and then attaching it via strobel, the method combines these operations into a single integrated process where the upper is formed and bonded directly to the sole assembly, reducing process complexity.
2Productivity
If material sections are directly bonded without traditional strobel, then manufacturing efficiency improves, but precise fitting and stability must be ensured through alternative methods
Solution Approach 1:
The last assembly is prepared in advance with vacuum holes positioned at specific locations before the upper material is applied. This preliminary configuration of the bonding apparatus ensures that when bonding occurs, precise fitting and stability are achieved without requiring traditional strobel construction, thus maintaining reliability while improving efficiency.
Solution Approach 2:
The patent uses vacuum pressure applied through holes in the last assembly to bond material sections to the sole assembly. This pneumatic bonding method provides uniform and controllable adhesion force, ensuring precise fitting and stable bonding without the need for traditional mechanical stitching or strobel layers, thereby improving manufacturing efficiency while maintaining reliability.
3Strength
If vacuum pressure is applied through holes in the last assembly, then material sections are effectively bonded, but the system requires sophisticated pressure control
Solution Approach 1:
The bonding system is segmented into multiple discrete vacuum holes distributed across the last assembly rather than using a single complex pressure application mechanism. This segmentation allows for distributed bonding force application, achieving strong and uniform bonding across the entire upper structure while keeping each individual vacuum hole simple in design and easy to control.
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
This method enables the efficient formation of a stable and comfortable footwear upper with improved manufacturing efficiency by directly bonding material sections without a traditional strobel, ensuring precise fit and stability.
Implementation Method 1
a pressing system that applies pressure and heat to shape and bond material sections directly
Implementation Method 2
a pressing system that applies pressure and heat to shape and bond material sections directly
Implementation Method 3
using vacuum holes and retractable pins for temporary fixation
Implementation Method 4
a flexible membrane to form a contoured upper structure
Implementation Method 5
a flexible membrane to form a contoured upper structure
Data Source
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AI summary
A method and system for making uppers for articles of footwear is disclosed. The system comprises a last assembly as well as a pressing system for forming uppers with the last assembly. The last assembly includes a last member and a base member. The last member is inverted so that the bottom surface of the last member is oriented away from the base member.