Ski Boot Closure Strand Sheath for Twist-Free Handling

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Solution Overview

Problem

Existing closure devices for footwear, such as ski boots, suffer from low stiffness of closure strands leading to difficult and uncomfortable handling due to twisting or hanging, resulting in cable clutter.

Innovation Solution

A closure device with a sheath arrangement that provides higher stiffness than the closure strand material, forming a self-supporting structure, and includes a telescopic sheath and stiffening members to maintain shape and flexibility, combined with a tensioning apparatus like a winding apparatus for controlled tensioning and releasing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the closure strand is made with low stiffness to allow tensioning by the tensioning apparatus, then the closure device can be tightened and loosened, but the closure strand tends to twist or hang down or protrude in an uncontrolled manner leading to difficult and uncomfortable handling

Engineering Contradiction:
Improvehandling of closure deviceVSAvoidcontrol of closure strand position
Core Design Contradiction:
Ease of operationVSStability of the object's composition

Solution Approach 1:

The closure strand is nested within a guiding sheath that provides structural support. The sheath encloses the closure strand along its entire length, preventing it from twisting or hanging down uncontrollably, while still allowing the closure strand to be tensioned by the tensioning apparatus when needed.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The guiding sheath acts as an intermediary between the closure strand and the external environment. It provides the necessary stiffness and guidance to control the closure strand's position, while allowing the closure strand to perform its function of tightening and loosening the closure device.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Stability of the object's composition

If the closure strand is given higher stiffness to prevent twisting and hanging, then handling becomes easier, but the closure strand becomes less flexible for tensioning by the tensioning apparatus

Engineering Contradiction:
Improvecontrol of closure strand positionVSAvoidflexibility of closure strand for tensioning
Core Design Contradiction:
Stability of the object's compositionVSAdaptability or versatility

Solution Approach 1:

The closure strand with higher stiffness is nested within the guiding sheath. The sheath provides the necessary flexibility and movement capability, allowing the closure strand to be tensioned by the tensioning apparatus while maintaining its positional control and resistance to twisting.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

Different parts of the closure device have different stiffness requirements. The closure strand itself is made with higher stiffness to prevent twisting, while the guiding sheath provides the necessary flexibility. This local differentiation of properties allows both requirements to be satisfied simultaneously.

Inventive Principle:
Principle #3Local quality

3Stability of the object's composition

If the closure strand is made with high stiffness via sheath arrangement, then twisting and hanging are prevented, but the device complexity increases due to additional sheath components

Engineering Contradiction:
Improvecontrol of closure strand positionVSAvoidstructure of closure device
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The guiding sheath is implemented as a flexible tubular structure that provides the necessary guidance and stiffness. This thin-walled flexible shell approach achieves the desired structural support with minimal additional complexity, as the sheath can be made from simple flexible materials and integrated into the closure device design.

Inventive Principle:
Principle #30Flexible shells and thin films

Data Source

PatentEP4470407B1Closure device, in particular for a ski boot, and ski boot comprising the same
Publication Date: 2025.12.24 HOJI UNLIMITED SOLUTIONS LTD
  • EP4470407B1 patent drawingFigure 1a
  • EP4470407B1 patent drawingFigure 1b
  • EP4470407B1 patent drawingFigure 1c

AI summary

A closure device (100), in particular for a ski boot (200), the closure device comprising a closure strand (102) which is designed and intended to be fixedly attached with at least one of its ends (102a, 102b) to a first basis portion (202a) of a basis unit (202), a closure strand receiving element (106a, 106b) which is designed and intended to be fixedly attached to a second basis portion (202b) of or fixedly connected to the basis unit, wherein the second basis portion is opposite the first basis portion, wherein in a closed state of the closure device, the closure strand is configured to be engaged with the closure strand receiving element, and in an opened state of the closure device, the closure strand is designed and intended to be not engaged with the closure strand receiving element, and a tensioning apparatus (112) which is designed and intended to be attached to the first basis portion of the basis unit, wherein the tensioning apparatus is operatively connected to the closure strand and configured to tension the closure strand along a longitudinal direction (I) of the closure strand, in the closed state of the closure device, wherein the closure device further comprises a sheath arrangement (114) which is configured to be arranged around the closure strand in an enveloping manner, wherein the sheath arrangement has a higher stiffness than the closure strand. The invention further refers to a ski boot comprising the closure device.