Friction-Shaft Pull-Cord Control for Cordless Curtain Lifting
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Solution Overview
Problem
Current curtain control devices, especially manual ones, face issues with gear control causing damage to pull cords, high production costs due to metal gears that rust, and difficulty in adjusting tension, making it troublesome to control the lifting position of curtains without an external power supply.
Innovation Solution
A pull-cord control device without an operation cord, featuring a base with first friction shafts and a pressing plate with second friction shafts that can be rotated to clamp or loosen the pull-cord, allowing for adjustable friction to facilitate curtain lifting, using a combination of friction shafts and gravity to balance the pulling force for arbitrary height adjustment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If gear control is used in manual curtain devices, then the curtain can be controlled to open and close, but the pull cords are easily damaged and the production cost increases due to metal gears rusting
Solution Approach 1:
The patent removes the gear control mechanism entirely from the curtain device, extracting only the essential function of controlling curtain movement. By eliminating the gear component, the patent avoids the problems of pull cord damage and metal rusting while maintaining the basic opening and closing function through a simpler friction-based mechanism.
Solution Approach 2:
The patent replaces expensive metal gears with inexpensive friction shafts that have a simpler structure and lower production cost. The friction shafts use friction-based control instead of mechanical gear engagement, reducing material costs and manufacturing complexity while achieving the required functional reliability.
2Ease of operation
If gear control is used in manual curtain devices, then the curtain can be controlled, but the device complexity increases and tension adjustment becomes difficult
Solution Approach 1:
The patent replaces the mechanical gear control system with a friction-based control mechanism. Instead of using interlocking gears to control movement, the patent uses friction shafts that create friction with the pull cord to control tension and movement, simplifying the overall device structure and making tension adjustment more intuitive and easier to operate.
3Ease of operation
If friction shafts are used to increase friction with the pull-cord, then the curtain lifting position can be easily adjusted, but the device complexity increases
Solution Approach 1:
The patent divides the friction control function into multiple friction shafts distributed along the pull cord path. Each friction shaft provides localized friction control, and their combined effect enables precise tension adjustment and lifting position control. This segmentation allows the device to achieve fine control without requiring a single complex control 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
The device effectively increases friction between the control device and the pull-cord, enabling easy adjustment of the curtain's lifting position, reducing damage and production costs, and allowing for precise control of the curtain's height without the need for external power.
Implementation Method 1
The base forms a plurality of first friction shafts. The pressing portion forms a plurality of second friction shafts staggered with the corresponding first friction shafts... When the pressing plate is in the clamping portion, the second friction shafts actuate the pull-cord to wander between the first friction shafts and the second friction shafts
Data Source
AI summary
A pull-cord control device for a curtain without an operation cord includes a pull-cord (3), a base (1), and a pressing plate (2) rotatably mounted to the base through a rotation shaft (42). The base forms first friction shafts (11). The pressing plate forms second friction shafts (21) staggered with the first friction shafts. The pressing plate forms a fixing pole (41). A first end of the pull-cord is connected to a retractable-cord device (5), and a second end of the pull-cord extends between the first and second friction shafts, and is connected to a curtain body (6) after extending about the fixing pole. When the curtain body moves up and down, the pressing plate is rotated between a clamping position and a loose position. When the pressing plate is in the clamping portion, the second friction shafts actuate the pull-cord to wander between the first and second friction shafts.