Roller Blind Spring-Loaded Winding Shaft Sagging
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Solution Overview
Problem
Conventional roller blind systems for sliding roof systems face challenges with wind-up springs, including dimensioning issues, self-adjustment, and varying friction conditions over the life of the blind, which are difficult to manage effectively.
Innovation Solution
A roller blind system with a spring-loaded winding shaft extending transversely across the flexible material, combined with spiral springs for winding and guiding, and a helical spring for tensioning in the circumferential direction, which reduces sagging and eliminates the need for additional guiding elements like metal strips.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a conventional winding spring is used to wind up the roller blind, then the roller blind can be wound up from any position, but the roller blind may adjust itself undesirably due to high spring force and varying friction conditions
Solution Approach 1:
The winding mechanism is segmented into two independent spring systems: spiral springs for winding capability and a weak circumferential spring for tensioning. This segmentation allows each spring to have optimized, independent functions - the spiral springs provide strong winding force from any position while the weak circumferential spring provides minimal tensioning to prevent self-adjustment.
Solution Approach 2:
Different parts of the system have different spring characteristics tailored to local needs: the spiral springs have high spring constant for winding action, while the circumferential spring has low spring constant for tensioning only. This local quality differentiation resolves the contradiction by applying appropriate spring strength at appropriate locations.
2Shape
If tensioning devices are applied in the transverse direction to prevent sagging, then the roller blind is kept taut, but additional guiding elements like metal strips are required
Solution Approach 1:
The guiding function and tensioning function are merged into the spiral springs. The spiral springs simultaneously provide winding force, guiding force, and tensioning force, eliminating the need for separate metal strips or guiding elements. This merging reduces device complexity while maintaining the tautness of the roller blind.
Solution Approach 2:
The spiral springs are designed to perform multiple functions: winding the roller blind, guiding it in the guide rails, and tensioning it in the longitudinal direction. This multi-functionality eliminates the need for additional dedicated components for each function, reducing overall device complexity.
3Shape
If strong spring loading is used to tighten the flexible material, then sagging is reduced, but the roller blind may self-adjust due to high tensile force
Solution Approach 1:
The spring constant of the circumferential spring is changed to a low value, providing just enough tensile force to reduce sagging but not enough to cause self-adjustment. This parameter optimization resolves the contradiction by finding the precise balance between tautness and position stability.
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 system ensures the roller blind is kept taut and minimizes sagging with a low tensile force, allowing for reliable operation and reduced noise, while the spiral springs handle winding and guiding, ensuring the blind remains in the desired position without self-adjustment.
Implementation Method 1
two spiral springs that extend in a longitudinal direction of the roller blind, are firmly connected to the longitudinal edges of the flexible material and contract to form a spiral
Implementation Method 2
A spring element is also particularly preferably provided, which acts on the winding shaft in the circumferential direction relative to the bearing axis
Implementation Method 3
a plastic shrink tube can be provided between the bearing axis and the winding shaft. This optional heat-shrink tubing usually covers the rigid bearing axis directly, in order to prevent undesirable noise development when the winding shaft rotates relative to the rigid bearing axis
Data Source
Figure 1
Figure 2~3
Figure 4~6
AI summary
The roller blind (10) has a flexible material (13) that partially covers a roof opening, and two coil springs (24), which extend in longitudinal direction (11) of the roller blind. A spring-loaded winding shaft (26) is provided, which extends transversely to the longitudinal direction continuously from a longitudinal edge (16) of flexible material to an opposite longitudinal edge. The spring-loaded winding shaft is firmly connected with a transverse edge (28) of the flexible material.