Composite Ski Boot Base with Angled Carbon Fiber for Torsional Stiffness
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Solution Overview
Problem
Conventional ski boot bases lack sufficient strength and torsional stiffness, leading to deformation under high loads and poor ski control, as they often shear or deform when attached to ski bindings, especially during Nordic skiing.
Innovation Solution
A fiber-reinforced composite sole with angled carbon fiber yarns in a laminate structure, combined with rigid elastomeric outsole elements and a heel portion for enhanced torsional stability, is used to create a base that maintains structural integrity and flexibility, incorporating a polymer matrix and balanced plain weave fabric layers oriented at specific angles to optimize torsional and flexural stiffness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional injection moulded plastic material is used for the base, then ease of manufacture is improved, but strength and torsional stiffness are insufficient leading to deformation under high loads
Solution Approach 1:
The base is constructed as a composite structure combining a plastic sole with integrated carbon fiber reinforcement elements. The carbon fiber bars are embedded within the plastic material to provide tensile strength and torsional stiffness, while the plastic matrix maintains ease of manufacture through injection molding processes. This composite approach resolves the contradiction by combining the manufacturing advantages of plastic with the strength benefits of carbon fiber reinforcement.
2Strength
If harder plastic material is used to increase strength, then strength is improved, but the material shears off or deforms under high loads reducing reliability
Solution Approach 1:
The use of carbon fiber reinforced plastic creates a composite material that combines the toughness of plastic with the high strength-to-weight ratio of carbon fiber. The carbon fiber reinforcement prevents the plastic from shearing or deforming under high loads, while the plastic matrix provides impact absorption and manufacturing flexibility. This composite structure achieves both strength and reliability by distributing mechanical loads across the reinforcement network.
Solution Approach 2:
The invention changes the material parameters by incorporating carbon fiber reinforcement at specific orientations within the plastic matrix. The carbon fiber is positioned to align with expected stress patterns, maximizing strength where needed while maintaining plastic's inherent toughness. This parameter modification allows the material to withstand high loads without shearing or permanent deformation.
3Stability of the object's composition
If the base is made more rigid to prevent deformation, then torsional stiffness is improved, but flexibility for walking and skiing is reduced
Solution Approach 1:
The carbon fiber reinforcement is strategically positioned within the base structure to provide localized strength enhancement. The reinforcement is concentrated in areas subject to high torsional loads, such as the heel and midfoot regions, while maintaining flexibility in the toe and forefoot areas where bending is needed for walking and skiing. This local quality approach allows the base to be rigid where required without compromising overall flexibility.
Solution Approach 2:
The composite structure of carbon fiber reinforced plastic allows different regions of the base to have different effective stiffness characteristics. The carbon fiber provides torsional rigidity in the heel and midfoot, while the plastic matrix maintains flexibility in the forefoot and toe areas. This material composite enables simultaneous achievement of torsional stiffness and operational flexibility through spatial variation in structural properties.
Data Source
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AI summary
A base (1) is provided for a ski boot (2) and comprises a one-piece sole (4) defining heel and toe portions (6, 7) that is adapted to be secured to one or more outsole elements (8, 9, 10). Preferably, toe and heel outsole elements (8, 9) are bonded to the toe and heel portions (6, 7) respectively to form a base (1) with a unitary construction. The sole (4) also has a fiber-reinforced composite structure wherein a majority of the fibers in at least a mid-section (7) of the sole (4) between the heel and toe portions (6, 7) are angled at an acute angle with respect to a longitudinal axis (L) of the sole (4). Preferably, the mid-section (7) of the sole covers a position anatomically beneath the location of the metatarsal bones and the plantar arch of a person wearing the ski boot and a majority of the fibers in this mid-section (7) of the sole are angled at substantially ±45° ± 10° to the longitudinal axis (L) of the sole (4) and between 5% and 10% of the fibers in the mid-section (7) of the sole (4) are substantially aligned with the longitudinal axis of the sole at angles within ±20° of being parallel to the longitudinal axis (L) of the sole (4). A ski boot (2) incorporating such a sole (4) is also provided.