Protective Sleeve for Steering Cable Routing

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Solution Overview

Problem

Control means, such as electrical cables, routed through the frame of bicycles with electric auxiliary motors, are prone to damage due to relative movements between the head tube and steerer tube during steering, as they are not adequately protected from contact with the steerer tube's circumference or interior.

Innovation Solution

A protective sleeve, made of deformable materials like plastic or elastomeric fabric, is arranged between the control means and the steerer tube to prevent direct contact and damage, potentially extending into the frame tube to cover sharp edges, and can be integrated with the centering ring for easier assembly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If control elements are routed through the centering ring into the frame, then cable routing appearance is improved and cables are protected from external damage, but control cables may chafe against the steerer tube or head tube due to relative movements during steering

Engineering Contradiction:
Improveprotection of control cables from dirt and moistureVSAvoidrisk of cable damage from chafing
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

A protective sleeve is introduced as an intermediary component between the control cable and the moving parts (steerer tube and head tube). The sleeve is fixed to the head tube and extends along the steerer tube, creating a protective barrier that prevents direct contact and chafing while allowing the necessary relative movements during steering operations.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The protective sleeve is made from a flexible material that can accommodate the relative movements between the head tube and steerer tube during steering. The flexible nature of the sleeve allows it to maintain protection while adapting to the dynamic geometry changes, preventing chafing without restricting necessary motion.

Inventive Principle:
Principle #30Flexible shells and thin films

2Reliability

If a protective sleeve is added inside the head tube, then control elements are protected from chafing, but device complexity increases

Engineering Contradiction:
Improveprotection of control cables from chafingVSAvoidadditional protective sleeve component
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The protective sleeve is merged with the centering ring assembly, which is already a necessary component of the headset system. By integrating the protective function into an existing structural element rather than adding a completely separate component, the increase in device complexity is minimized while still achieving the desired protection.

Inventive Principle:
Principle #5Merging (Combining)

3Ease of operation

If the protective sleeve is made of deformable material, then steering forces are minimized, but protection effectiveness may be reduced

Engineering Contradiction:
Improvesteering force requirementsVSAvoidprotection capability against sharp edges
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The protective sleeve exhibits different material properties at different locations: it has enhanced protection characteristics (greater thickness or hardness) in areas subject to chafing and contact with sharp edges, while maintaining flexibility and deformability in other areas to minimize impact on steering forces. This localized differentiation of material properties optimizes both protection and operational ease.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP3552938B1Fork-frame unit
Publication Date: 2021.02.24 ZEG ZWEIRAD EINKAUFS GENOSSENSCHAFT EG
  • EP3552938B1 patent drawingFigure 1
  • EP3552938B1 patent drawingFigure 2
  • EP3552938B1 patent drawingFigure 3

AI summary

In a fork-frame unit (10) for a two- or three-wheeled vehicle, in which a vehicle fork (15) with its fork steerer tube (17) is rotatably mounted in a head tube (14) of the frame, and in which at least one flexible control element, such as an electrical cable (23), is guided from the outside into the interior of the frame through a centering ring (20) into the space between the inside of the head tube and the outside of the fork steerer tube, the invention provides that at least one protective sleeve (25) for the control element is arranged inside the head tube between the head tube and the fork steerer tube, effectively preventing damage to the control element. (See Fig. 1)