Shoe Upper Overlap Region for Lateral Bulging Suppression
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Solution Overview
Problem
Shoes often experience 'lateral bulging' due to insufficient rigidity in the upper, leading to poor foot conformity and increased risk of buckling during dorsiflexion, which affects performance in various sports and activities.
Innovation Solution
The shoe upper features a first and second upper portion with an overlap region that increases in area during dorsiflexion, supported by a separation line positioned anterior to the metatarsal phalangeal joint and posterior to the fourth toe, preventing buckling and enhancing foot conformity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If polyurethane or similar materials are used to increase the rigidity of the upper on the lateral side of the forefoot portion to suppress lateral bulging, then lateral bulging is suppressed, but the upper locally bends when the foot is dorsiflexed, causing buckling and deteriorating foot conformity
Solution Approach 1:
The upper is divided into multiple portions (first upper portion covering the toe, second upper portion covering the ball of the little toe) with a separation line between them. This segmentation allows different regions to have different degrees of flexibility, enabling the upper to maintain rigidity for suppressing lateral bulging while allowing controlled bending for foot conformity during dorsiflexion.
Solution Approach 2:
Different portions of the upper are designed with different properties. The first and second upper portions are configured to provide support and suppress lateral bulging, while the overlap region with separation line is designed to allow relative displacement and bending. This local differentiation enables the upper to have both rigid support functions and flexible adaptation functions in different regions.
2Stability of the object's composition
If the upper has high rigidity to suppress lateral bulging, then lateral stability is improved, but buckling occurs during dorsiflexion, reducing the synchronization with foot movement
Solution Approach 1:
The overlap region between the first and second upper portions is designed to be dynamic, allowing relative displacement between these portions during foot dorsiflexion. This dynamic design enables the upper to adapt to foot movement while maintaining overall structural stability for suppressing lateral bulging.
Solution Approach 2:
The problem is solved by introducing a new dimension of movement through the overlap region, where the second upper portion can displace relative to the first upper portion in the front-rear direction. This additional degree of freedom allows the upper to maintain lateral stability while accommodating dorsiflexion movement.
3Reliability
If the upper is made rigid to prevent lateral sliding of the foot, then lateral bulging is suppressed, but the upper cannot bend in sync with the foot, deteriorating comfort and conformity
Solution Approach 1:
The upper is segmented into multiple portions with a separation line, allowing different regions to perform different functions. The segmented structure provides reliable foot support through the first and second upper portions while enabling bending conformity through the overlap region where relative displacement occurs.
Solution Approach 2:
Different local regions of the upper have different properties: the first and second upper portions provide stable support for suppressing lateral bulging, while the overlap region provides local flexibility for bending during dorsiflexion. This local quality differentiation achieves both reliable support and good conformity.
Data Source
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AI summary
An upper including: a first upper portion covering a lateral side of a toe; a second upper portion for providing a support covering a side surface of a ball of a little toe; an overlap region where the first upper portion and the second upper portion overlap each other on the lateral-side surface in a standstill position and a dorsiflexed state; and a separation line at which the first upper portion and the second upper portion are separated from each other so that as the foot dorsiflexes from the standstill position, a front end of the second upper portion displaces with respect to the first upper portion so as to increase an area of the overlap region, wherein a position of a lower end of the separation line is set to be anterior to a metatarsal phalangeal joint of the little toe and posterior to a tip of a fourth toe.