Awning Cable Tensioning with Intermediate Roller
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Solution Overview
Problem
Existing awning systems with removable sail corners face design complexities due to uneven tension distribution and wrinkling issues when sail corners are not perpendicular to the winding shaft, especially when the distance between corners is considerable, leading to inefficient winding and unwinding processes.
Innovation Solution
The introduction of a stationary intermediate roller guides the cable strand between deflection rollers in a plane perpendicular to the winding shaft, ensuring that the change in length of the cable strand section between the intermediate and deflection pulleys corresponds to the sail corner extension, maintaining uniform tension and preventing wrinkles during winding and unwinding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the cable pull is routed directly between deflection rollers without an intermediate roller, then the structure is simpler, but the cable strand does not maintain perpendicular orientation to the winding shaft during extension, causing uneven tension and wrinkling
Solution Approach 1:
A stationary intermediate roller is introduced as a mediator element in the cable pull system. This intermediate roller serves as a reference point that ensures the cable strand section between it and the deflection roller maintains perpendicular orientation to the winding shaft during sail corner extension. The intermediate roller acts as a geometric constraint that enforces the perpendicular cable routing, thereby ensuring uniform tension distribution across the sail corners while the cable pull operates.
2Length of stationary object
If the distance between deflection roller and intermediate roller is insufficient, then the structure is more compact, but the maximum extension length of the sun sail cannot be fully utilized and winding conditions deteriorate
Solution Approach 1:
The distance parameter between the deflection roller and the intermediate roller is explicitly set to correspond to the maximum extension length of the sun sail. This parameter optimization ensures that when the sail is fully extended, the cable strand maintains proper perpendicular orientation throughout its path. The distance is not arbitrary but is precisely determined by the operational requirements of the sail's maximum extension, thereby optimizing both the structural configuration and the winding efficiency.
3Adaptability or versatility
If sail corners are not perpendicular to the winding shaft, then the awning can accommodate irregular shapes, but the tensile force deviates from perpendicular direction causing cable pull tension reduction and wrinkling
Solution Approach 1:
The stationary intermediate roller creates a geometric constraint that establishes an equipotential condition for the cable pull system. By anchoring the cable strand at a fixed intermediate point, the system ensures that the cable maintains perpendicular orientation to the winding shaft regardless of the sail's overall shape or the positions of its corners. This equipotential constraint on the cable routing ensures that the tensile force is always directed perpendicular to the winding shaft, preventing tension reduction and wrinkling while still allowing the sail to accommodate irregular shapes.
Data Source
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AI summary
The invention relates to a tensioning device for a sun shade (1) that can be pulled off a winding shaft (3), said shade comprising a cable control (10), which engages on shade corners (4, 5) that can be pulled off the winding shaft (3) in the opposite direction and which, in order to form a loop, runs across two deflection rollers (8, 9) associated each with one of the two shade corners (4, 5), one of which is stationary and the other is braced on a tensioning cable (11) approximately perpendicular to the winding shaft (3). In order to create advantageous winding conditions, it is proposed that the cable length (14) of the cable control (10) running between the deflection rollers (8, 9) is guided by way of a fixedly supported intermediate roller (15) and that the section (17) of the cable length (14) between the intermediate roller (15) and the deflection roller (8) braced on the tensioning cable (11) runs in a plane that is at least approximately perpendicular to the winding shaft (3), wherein the distance between the deflection roller (8) braced on the tensioning cable (11) and the intermediate roller (15) corresponds to at least the extension length of the shade corner (4) on the side of the tensioning cable (11) when the sun shade (1) is fully opened.