Cordless Window Shade Drum With Adjustable Spring Limiting
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Solution Overview
Problem
Existing window shades with cord-operated rotary drums require excessive cord lengths, affecting appearance and pose a child safety risk, while spring-operated systems are inflexible and require customization for specific shading assembly sizes.
Innovation Solution
A cordless window shade system with a spring unit and limiting mechanism that adjusts biasing force and locking states, allowing for flexible operation and secure positioning of shading elements without cords, using a torsion spring and spring adjustment mechanism to accommodate varying shading structure weights and lengths.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a cord-operated rotary drum system is used, then the shading assembly can be operated to wind or unwind, but the cord length becomes excessive affecting appearance and creating child safety risks
Solution Approach 1:
The patent removes the cord from the system entirely, extracting the harmful element while preserving the essential function of raising and lowering the shading assembly through a cordless mechanism
Solution Approach 2:
The patent replaces the traditional cord-based mechanical lifting system with a spring-based mechanical system that uses elastic potential energy to raise the shading assembly, eliminating the need for long cords
2Length of moving object
If a spring assembly is used to drive the rotary drum, then cord length is reduced and child safety is improved, but the control system becomes strictly adapted to specific length and weight requiring modifications
Solution Approach 1:
The patent introduces an adjustable spring mechanism where the spring constant and pre-load can be dynamically modified to accommodate different shading assembly weights and lengths, transforming a static system into a dynamic one
Solution Approach 2:
The patent enables changing the spring parameters (stiffness constant and initial compression) to adapt the system to different operating conditions, allowing the same basic mechanism to serve multiple applications
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 provides convenient, safe, and adaptable operation of window shades, ensuring stable positioning and adjustable light transmission without cords, addressing both aesthetic and safety concerns.
Implementation Method 1
a spring unit (122) connected with the rotary drum (120), wherein the spring unit (122) comprises a torsion spring
Implementation Method 2
a spring adjustment mechanism (152) connected with the spring unit (122), wherein the spring adjustment mechanism (152) is operable to adjust a biasing force applied by the spring unit (122)
Data Source
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AI summary
An actuating system for a window shade includes a fixed support shaft, a rotary drum pivotally connected with the support shaft, the rotary drum being rotatable for winding or unwinding a shading structure, and a limiting mechanism disposed inside the rotary drum and including a threaded portion provided on the support shaft, a stop portion, a limiting part, and a follower engaged with the threaded portion, the stop portion and the limiting part being respectively disposed adjacent to a first and a second end of the threaded portion, and the follower being rotationally coupled to and slidable relative to the rotary drum. The rotary drum is rotatable in a first direction to drive the follower to slide toward a first position for engagement with the limiting part, and in an opposite second direction to drive the follower to slide toward a second position for engagement with the stop portion.