Cordless Roller Blind Brake and Spring Self-Locking
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Solution Overview
Problem
Existing roller blinds, both mechanical and power-driven, face issues such as bead chain breakage, clutch damage due to torque, and aesthetic and safety concerns from entanglement, particularly affecting pets and children.
Innovation Solution
A cordless roller blind design featuring a roller tube with a coil spring and a brake device that balances torsion force, friction, and weight to allow manual operation and self-locking without external force, preventing excessive torque on components and incorporating an adjustable friction mechanism for different blind fabrics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a bead chain is used to wind and self-lock the roller tube, then the roller blind can be mechanically operated, but the bead chain breaks due to excessive pulling force and torque
Solution Approach 1:
The patent removes the bead chain from the system entirely, replacing it with a cordless design that uses a brake device and spring mechanism for winding and self-locking, thereby eliminating the component that was prone to breaking
Solution Approach 2:
The patent replaces the mechanical bead chain system with a friction-based brake device and spring mechanism, substituting the chain-based winding system with a brake-controlled rotation system that prevents excessive force transmission
2Ease of operation
If the roller blind self-locks using a clutch mechanism, then the blind fabric can be held in position, but the clutch is damaged by excessive torque from the blind fabric weight
Solution Approach 1:
The patent replaces the clutch mechanism with a brake device that uses friction to control rotation and achieve self-locking, eliminating the torque transmission issues that damaged the clutch while maintaining the self-locking function
Solution Approach 2:
The patent adjusts the friction coefficient of the brake device to optimize the balance between self-locking capability and torque limitation, ensuring the blind fabric weight is supported without excessive torque transmission
3Ease of operation
If a bead chain or cord is used for mechanical roller blind operation, then manual winding is enabled, but safety hazards arise from entanglement around necks of pets and children
Solution Approach 1:
The patent removes the bead chain and cord components from the system, replacing them with a cordless design that uses a brake device and spring mechanism, thereby eliminating the entanglement hazard while preserving manual operation capability
Solution Approach 2:
The patent implements a self-locking mechanism through the brake device and spring system that allows manual operation without requiring external cords or chains, enabling the system to serve itself through friction-based control
4Extent of automation
If a power-driven motor is used to rotate the roller tube, then automated operation is achieved, but the motor shaft bears full torque from the blind fabric weight causing load on the motor
Solution Approach 1:
The patent uses a spring mechanism that provides a counterbalancing force to offset the weight of the blind fabric, reducing the torque that the motor must overcome during operation and thereby decreasing the motor load
Solution Approach 2:
The patent replaces the direct motor-driven system with a brake-controlled friction system that limits torque transmission, substituting the motor shaft's direct load-bearing role with a friction-based torque management mechanism
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
Enables safe, aesthetically pleasing, and reliable operation by allowing manual raising and lowering with self-locking at desired positions, reducing component stress and preventing entanglement hazards, while allowing for adjustable friction to accommodate varying blind fabric weights.
Implementation Method 1
A coil spring is arranged in the roller tube, and a torsion force of the coil spring changes as the roller tube rotates
Implementation Method 2
The torsion force of the coil spring, friction provided by the brake device and a weight of a hanging portion of the blind fabric balance at equilibrium
Data Source
AI summary
A cordless roller blind includes a roller tube, a blind fabric wound around the roller tube, and at least one brake device. A coil spring is arranged in the roller tube, and the torsion of the coil spring changes as the roller tube rotates. The torsion force of the coil spring, the friction force provided by the brake device and the weight of a hanging portion of the blind fabric are mutually balanced, so that the blind fabric remains stationary at any position without an external force. When the external force pushes the blind fabric to move upward, pressure acting on the brake device decreases as the external force offsets the weight of the blind fabric, and the friction decreases accordingly, and the torsion force of the coil spring drives the blind fabric to wind up.