Convertible Soft Top Tensioning With Integrated Cable Winding

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Solution Overview

Problem

Conventional convertible top systems face challenges in maintaining optimal tension of the textile roof lining due to limited path for traction devices and complexity of the traction control system, leading to either insufficient or excessive clamping forces, which can result in damage or improper alignment.

Innovation Solution

A convertible top system with a winding and unwinding unit for the traction device, integrated with the existing gearbox and drive unit, allows for variable effective length of the traction means, ensuring the textile cover is kept in a tensioned state without excessive loads, using a cable pulley mechanism for efficient operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a tensioning device with deflection elements is used to maintain headliner tension, then the headliner remains taut when closed, but the design complexity increases considerably due to manufacturing tolerances and control requirements

Engineering Contradiction:
Improveheadliner tension maintenanceVSAvoidtensioning device complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent changes the parameter of tension element length from fixed to variable by introducing a winding unit. This allows the effective length of the tension element to be adjusted dynamically, simplifying the overall design while maintaining reliable headliner tension without complex deflection mechanisms

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent makes the tension element length dynamic through the winding unit, which can adjust the length in real-time. This dynamic adjustment replaces complex static deflection devices and enables reliable tension maintenance with simpler control

Inventive Principle:
Principle #15Dynamics

2Volume of moving object

If the tensioning device path is limited, then the convertible top structure is compact, but the control complexity of the tensioning device increases

Engineering Contradiction:
Improveconvertible top compactnessVSAvoidtensioning control complexity
Core Design Contradiction:
Volume of moving objectVSDevice complexity

Solution Approach 1:

The patent merges the tensioning control function with the existing convertible top drive mechanism by integrating the winding unit into the movable roof support structure. This combination maintains compactness while reducing control complexity by using the same drive system for both roof movement and tension adjustment

Inventive Principle:
Principle #5Merging (Combining)

3Device complexity

If the tension element length is not variable, then the design is simpler, but manufacturing tolerances cause either insufficient or excessive tension leading to damage

Engineering Contradiction:
Improvetensioning system simplicityVSAvoidtension control precision
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The patent introduces variable length capability through the winding unit, allowing the tension element length to be adjusted after manufacturing. This eliminates the need for extremely tight manufacturing tolerances while keeping the overall design simple, as the length can be programmed rather than precisely manufactured

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The winding unit can pre-adjust the tension element length before the convertible top is fully assembled or before operation begins. This preliminary adjustment ensures proper tension is achieved without requiring complex real-time control during operation

Inventive Principle:
Principle #10Preliminary action

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

This solution simplifies the design, reduces manufacturing costs, and ensures the textile cover is properly tensioned in all operating states, preventing damage and maintaining optimal tension without excessive loads.

Implementation Method 1

The cable pulley is non-rotatably connected to a rotatable component (14) of a gearbox (10)

Methodology Applied
Scientific EffectPulley: Pulley

Data Source

PatentEP4015269B1Soft top for a convertible
Publication Date: 2023.08.30 VALMET AUTOMOTIVE OY
  • EP4015269B1 patent drawingFigure 1
  • EP4015269B1 patent drawingFigure 2
  • EP4015269B1 patent drawingFigure 3

AI summary

A convertible top (1) for a convertible vehicle (2) is described, which is movable between a closed position and an open, stowed position and which comprises at least one textile cover (6). In the closed position of the convertible top (1), the cover (6) at least partially covers a convertible top mechanism (7) which is equipped with at least one gear (10). Additionally, the cover (6) is operatively connected to the convertible top mechanism (7) via at least one tension member (8). The tension member (8) is designed to hold the cover (6) in a taut state when the convertible top (1) is closed. The effective length of the tension member (8) can be varied by means of a winding and unwinding unit (12).