Reversible Last Extension Mating for Robotic Shoe Assembly
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Solution Overview
Problem
The manufacturing of shoes is labor-intensive due to variations in materials and conditions, leading to imprecision in tooling and assembly, which is costly and time-consuming, especially when using precision machined lasts.
Innovation Solution
A last extension with a mounting mechanism and a unique pattern is used to automate the manufacturing process, allowing robotic manipulation and precise identification of critical points on the shoe, reducing the need for human compensation and enabling consistent assembly across different shoe designs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If precision machined lasts are used, then manufacturing precision is improved, but device complexity and cost increase
Solution Approach 1:
The last is divided into two separate parts: a reusable last body and a disposable last extension. The last body contains the precision-machined mounting mechanism, while the last extension is a simpler, pattern-marked component that is attached temporarily for manufacturing operations and then discarded. This segmentation allows precision to be concentrated in the mounting mechanism rather than the entire last assembly.
Solution Approach 2:
The last extension is designed as a disposable component that is attached to the last body, used for a single manufacturing operation, and then discarded. This eliminates the need to precision-machine entire lasts for each shoe design, as only the reusable last body requires precision manufacturing. The disposable extension carries only the necessary pattern markers for robotic identification.
2Adaptability or versatility
If human operators manually compensate for variations, then adaptability is improved, but productivity decreases
Solution Approach 1:
The manual visual inspection and compensation performed by human operators is replaced with an automated vision system that reads the machine-readable pattern on the last extension. The pattern contains encoded information about the last's geometry and critical points, allowing robotic systems to automatically compensate for variations without human intervention. This substitution of manual processes with automated systems increases productivity while maintaining adaptability.
Solution Approach 2:
Instead of requiring human operators to physically measure and compensate for variations, the critical geometric information is copied into a machine-readable pattern on the last extension. This pattern serves as a digital twin or representation of the last's key features, enabling automated systems to access and process this information quickly and accurately, thereby increasing productivity while maintaining the adaptability to handle variations.
3Adaptability or versatility
If multiple shoe designs are manufactured, then adaptability is improved, but manufacturing precision deteriorates due to retooling
Solution Approach 1:
The last body is designed as a universal platform with a standardized mounting mechanism that can accommodate multiple different last extensions corresponding to different shoe designs. Instead of creating precision-machined lasts for each shoe model, the same precision last body is reused with different disposable extensions. This universal mounting system maintains precision across multiple designs while enabling rapid changeover between different shoe styles.
Solution Approach 2:
The critical geometric information for each shoe design is pre-encoded into the machine-readable pattern on the respective last extension before manufacturing begins. This preliminary encoding of design-specific information allows the automated system to quickly adapt to different shoe designs by simply reading the pattern on the attached extension, without requiring retooling or recalibration of the precision mounting mechanism. This maintains manufacturing precision while enabling versatility.
Data Source
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AI summary
The application relates to a method for reversibly mating a last for an article of footwear to a last extension, the method comprising: providing a last, the last having a first cavity and a second cavity on the last; providing a last extension, the last extension comprising: a body; a generally planar lower surface of the body; and a first protrusion and a second protrusion protruding from the lower surface of the body, and moving the openings of the cavities along the lower surface of the body of the last extension, such that the cavities at least partially envelop the protrusions.