Rotatable Spring Motor Shaft for Compact Vehicle Sun Blind

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Solution Overview

Problem

Existing sun blinds for motor vehicle windows require significant space and high restoring forces, making them bulky and uncomfortable to manually operate or requiring large drive motors, especially in compact areas like side windows.

Innovation Solution

A sun protection roller blind with a rotatable spring motor shaft synchronized with a pull-out profile, reducing the necessary restoring force and allowing for a more compact design, combined with an optional electric geared motor for remote control and space-saving components like toothed cords for force transmission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If a stationary shaft is used in the spring motor, then sufficient tension is maintained in the roller blind web, but the restoring force required becomes too great, increasing space requirements and manual operation difficulty

Engineering Contradiction:
Improverestoring forceVSAvoidmanual pull-out comfort
Core Design Contradiction:
ForceVSEase of operation

Solution Approach 1:

The shaft of the spring motor is made rotatable relative to the winding shaft, transforming a static system into a dynamic one. During unwinding, the shaft rotates in the unwinding direction, allowing the spring element to wind up and store energy. During winding, the shaft rotates in the winding direction, allowing the spring to unwind and provide restoring force. This dynamic adjustment optimizes the restoring force throughout the operation cycle.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The rotational state of the shaft changes depending on the operation phase. When the roller blind is pulled out, the shaft rotates to wind the spring, changing the spring's winding state. When the blind is wound back, the shaft rotates in the opposite direction, allowing the spring to unwind. This parameter change enables the spring element to provide consistent tension while reducing peak restoring force requirements.

Inventive Principle:
Principle #35Parameter changes

2Force

If a high restoring force spring element is used, then the roller blind can be wound up effectively, but the space required for the sun blind increases

Engineering Contradiction:
Improverestoring forceVSAvoidspace requirement
Core Design Contradiction:
ForceVSVolume of moving object

Solution Approach 1:

The rotatable shaft enables the spring motor to dynamically adjust its mechanical advantage throughout the winding/unwinding cycle. By rotating the shaft, the spring element can be pre-compressed or pre-tensioned to provide the necessary restoring force without requiring a physically large spring mechanism, thus reducing space requirements.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The shaft rotation introduces an additional rotational degree of freedom that allows the spring element to store and release energy more efficiently. This dimensional change enables the same restoring force to be achieved with a more compact spring configuration, reducing the overall volume required for the spring motor assembly.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Force

If a high restoring force is required, then the roller blind can be wound up, but a more powerful drive motor is needed, increasing installation space requirement

Engineering Contradiction:
Improverestoring forceVSAvoidinstallation space
Core Design Contradiction:
ForceVSVolume of stationary object

Solution Approach 1:

The rotatable shaft creates a dynamic transmission mechanism where the spring element's restoring force is modulated throughout the operation cycle. During manual pull-out, the shaft rotates to wind the spring, storing energy. During automated winding, the spring unwinds to assist the motor, reducing the peak power and size requirements for the drive motor.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The rotatable shaft acts as an intermediary between the spring element and the winding shaft, enabling the spring to provide variable restoring force assistance. This intermediary mechanism allows the system to achieve effective winding with a smaller drive motor by leveraging the spring's energy storage and release capabilities through rotational motion.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 solution provides a compact, efficient sun protection system that reduces space requirements and enhances operational comfort by minimizing the required restoring force and allowing for remote control operation, while maintaining sufficient tension in the roller blind.

Implementation Method 1

a spring element, the roller blind can be pulled off the winding shaft against a restoring force of the spring element and the roller blind can be pulled off by the Restoring force of the spring element can be wound up

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

a torsion spring being arranged between the winding coil arrangement and the winding shaft, which is preloaded by rotating the winding coil arrangement and winding shaft relative to one another in the sense of tensioning the composite system

Methodology Applied
Scientific EffectTorsion spring: Torsion Spring

Data Source

PatentEP1970234A2Sun roller blind for motor vehicles
Publication Date: 2008.09.17 BOS GMBH & CO KG
  • EP1970234A2 patent drawingFigure 1
  • EP1970234A2 patent drawingFigure 2~3
  • EP1970234A2 patent drawingFigure 4

AI summary

The anti-glare shield blind i.e. side window blind (2) has a blind strip (21) detachable from a winding shaft (20) against a resetting force of a spring element. The blind strip is wounded on the winding shaft by the resetting force of the spring element. A spring motor has a shaft (33) that is twistably supported relative to the winding shaft, and the spring element is arranged between the shaft and the winding shaft. Rotating motion of the shaft is synchronized with a displacement of an extension profile (22) during detachment of the blind strip.