Adjustable Torsion Spring for Roller Blinds
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Solution Overview
Problem
Standard spring-assisted roller blinds often experience uneven operating forces due to mismatched spring characteristics, leading to unbalanced operation and increased complexity in manufacturing for various blind sizes and fabric weights.
Innovation Solution
A method to adjust the spring constant of a torsion spring by using a damper to reduce the number of active coils, effectively altering the spring torque and matching the torque changes with the weight of the fabric as it is rolled or unrolled, ensuring balanced operation with a single spring suitable for multiple blind sizes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a single spring is used for multiple blind sizes, then manufacturing inventory is reduced, but the operating force becomes uneven
Solution Approach 1:
The spring is segmented into active and inactive coils by introducing a damper that contacts specific coils, allowing the spring to function as multiple springs with different effective lengths. This enables a single physical spring to serve multiple blind sizes while maintaining balanced operating force.
Solution Approach 2:
The effective spring constant is changed by varying the number of active coils through damper positioning. By adjusting which coils are active versus inactive, the spring characteristics can be optimized for different blind weights and sizes without changing the physical spring itself.
2Ease of operation
If spring characteristics are customized for each blind, then operating force is balanced, but manufacturing complexity and inventory increase
Solution Approach 1:
A single spring design with multiple coils serves multiple functions by accommodating different blind sizes and weights. The damper mechanism allows the same spring to be optimized for different applications through selective coil engagement, eliminating the need for custom springs for each blind.
Solution Approach 2:
The system transitions from a static spring configuration to a dynamic one where the damper can be positioned to activate or deactivate specific coils based on the blind's requirements. This dynamic adjustment capability allows one spring to adapt to multiple scenarios.
3Ease of manufacture
If the spring is oversized or undersized, then manufacturing is simplified, but the cylinder acceleration becomes uneven
Solution Approach 1:
By segmenting the spring into active and inactive portions using a damper, the system can use an oversized spring while keeping only the necessary number of coils active. This maintains uniform cylinder acceleration by ensuring the active spring length matches the specific blind's requirements.
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 approach provides consistent operating force throughout the extension and retraction of the blind, reduces torque requirements, and allows for a single spring to be used across different sizes, minimizing manufacturing inventory and extending motor lifespan.
Implementation Method 1
The spring winds and tightens when the blind is lowered by an operator so that upon lifting the blind, the spring can release the stored energy
Implementation Method 2
A method to adjust the spring constant of a torsion spring by using a damper to reduce the number of active coils
Data Source
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AI summary
The present invention relates to a method for altering the spring constant (k) of a torsion spring for a roller blind, the method including (i) locating a dampener at a predetermined length along a longitudinal axis of the torsion spring, and (ii) tightening an end of the torsion spring against the dampener to increase the spring constant. The invention further relates to a roller blind system comprising a cylinder, a fabric attached to said cylinder for winding and unwinding from said cylinder, a torsion spring and a damper moveable along the longitudinal axis of the spring.