Sports Shoe String Fastening Lever for Quick Tightening

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Solution Overview

Problem

Conventional cable winding mechanisms in sports shoes, particularly ski boots, face issues such as malfunction due to kinks or irregularities, abrasion, complexity, and cumbersome operation, leading to unreliable foothold and high costs.

Innovation Solution

A fastening mechanism featuring a string and a string actuator with pretensioning means and a fastening lever, allowing direct string pulling for quick loosening and lever-assisted tightening, providing improved usability and reliability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a cable winding mechanism is used to tighten the shoe, then the shoe can be closed and secured to the foot, but the mechanism becomes complex and expensive

Engineering Contradiction:

Improvereliable footholdVSAvoidmechanism complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The fastening mechanism is divided into two independent parts: a pretensioning means for initial cable tensioning and a fastening lever with cam mechanism for final tightening. This segmentation allows each component to be simple while the combination achieves reliable fastening, eliminating the need for a complex winding mechanism.

Inventive Principle:

Principle #1Segmentation

2Reliability

If a cable winding mechanism is used to control a larger amount of cable, then the shoe can be properly fastened, but the operation becomes cumbersome requiring high number of rotations

Engineering Contradiction:

Improveproper fasteningVSAvoidoperation ease

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The cam mechanism on the fastening lever provides periodic mechanical advantage during its rotation, allowing the cable to be tightened rapidly with minimal lever rotations. The cam profile is designed to convert small lever movements into large cable tension changes, eliminating the need for numerous rotations required by winding mechanisms.

Inventive Principle:

Principle #19Periodic action

3Reliability

If a cable winding mechanism is used, then the shoe can be closed tightly, but the mechanism is prone to malfunction due to kinks or irregularities in the cable

Engineering Contradiction:

Improveshoe closure reliabilityVSAvoidcable kinks and irregularities

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The pretensioning means is designed to initially tension the cable and position it properly before the fastening lever is engaged. This preliminary action ensures the cable is free of kinks and irregularities before the main fastening operation, preventing malfunctions during tightening.

Inventive Principle:

Principle #10Preliminary action

4Reliability

If the cable runs across the shell and tightening tongue, then both shell and tongue are pressed towards the foot providing improved foothold, but the repeated deflection causes additional abrasion or damage to the cable

Engineering Contradiction:

Improveimproved footholdVSAvoidcable durability

Core Design Contradiction:

ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The string path is designed with sufficient clearance and proper routing to minimize sharp bends and deflection points. The pretensioning means applies initial tension that stabilizes the string path, reducing repeated flexing and abrasion at critical points where the string contacts the shell and tightening tongue, thereby extending cable life while maintaining foothold.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

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 combination of pretensioning means and a fastening lever enables faster, more intuitive, and reliable shoe closure with enhanced foothold and reduced wear, while maintaining simplicity and affordability.

Implementation Method 1

the fastening device comprises a fastening lever configured for pulling the string via lever transmission

Methodology Applied

Scientific EffectLever transmission: Lever

Implementation Method 2

pretensioning means configured for directly pulling or releasing the string

Methodology Applied

Scientific EffectDirect mechanical force: Mechanical Force

Data Source

PatentEP4649855A1Sports shoe with string fastening mechanism

Publication Date: 2025.11.19 BARTHEL FRITZ

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AI summary

The present invention relaters to a sports shoe 10 comprising a shell 12, a sole 14 attached to the shell 12, an inner member arranged at an instep region on an inner side of the shell 12, a fastening mechanism 16 which can be operated by a user to open or close the shoe 10, wherein the fastening mechanism 16 comprises a string 18 and a string actuator 22 coupled to the string to exert a pulling force to the string 18 for closing the shoe 10, wherein the string actuator 22 comprises a fastening lever 20 coupled to the string 18 and pivotable about a pivot axis 36 to pull or release the string 18, pretensioning means 38, 40 for pulling or releasing the string 18 without pivoting the fastening lever 20.