Retrofitable Retractable Screen System Using Pulley-Cord Mechanism

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Solution Overview

Problem

Existing screen systems for windows and doors are often permanently installed, obstructing views, requiring separate screens for ventilation, and complicating maintenance, while also limiting access for cleaning.

Innovation Solution

A retrofitable retractable screen system that uses a spindle pulley mechanism with a tension adjustment arrangement and guide components to allow the screen to be easily extended and retracted, providing unobstructed views when closed and easy access for maintenance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a permanent screen system is installed in a window frame, then the screen provides continuous protection against insects and debris, but the screen obstructs the view and limits access for cleaning and maintenance

Engineering Contradiction:
Improvecontinuous protectionVSAvoidaccess for cleaning
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The screen system transitions from a static permanent installation to a dynamic retractable mechanism. The screen can be extended to cover the window opening for protection and retracted to provide unobstructed access for cleaning and maintenance activities, resolving the contradiction between continuous protection and ease of maintenance access

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The screen system is divided into separable components including the screen material, support structure, and mounting mechanism. This segmentation allows the screen to be independently operated, extended, and retracted without affecting the window frame or other components, enabling easy access for cleaning while maintaining protection when needed

Inventive Principle:
Principle #1Segmentation

2Illumination intensity

If a retractable screen mechanism is added to provide unobstructed views, then the view is improved when the screen is retracted, but the device complexity increases

Engineering Contradiction:
Improveview clarityVSAvoidmechanism complexity
Core Design Contradiction:
Illumination intensityVSDevice complexity

Solution Approach 1:

The retractable screen mechanism serves multiple functions: it provides insect and debris protection when extended, allows unobstructed views when retracted, and facilitates easy access for cleaning and maintenance. This multi-functionality justifies the added complexity by delivering multiple benefits from a single integrated system

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The screen mechanism is designed to be easily operated by the user without requiring complex control systems. The retractable mechanism can be manually or automatically operated to extend or retract the screen as needed, providing self-service functionality that reduces the need for professional installation and maintenance of complex mechanisms

Inventive Principle:
Principle #25Self-service

3Stability of the object's composition

If a screen frame is permanently mounted to the window, then the screen provides stable support, but access to the window for cleaning is restricted

Engineering Contradiction:
Improvescreen support stabilityVSAvoidwindow access
Core Design Contradiction:
Stability of the object's compositionVSEase of operation

Solution Approach 1:

The screen support system transitions from a fixed permanent mounting to a dynamic retractable mechanism. The screen can be extended to provide stable support for protection and retracted to allow unobstructed access to the window for cleaning, resolving the contradiction between stability and ease of access

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The retractable mechanism acts as an intermediary between the screen material and the window frame. This intermediary component allows the screen to be mounted to the frame while still enabling easy access to the window by retracting the screen, decoupling the stability of the mounting from the accessibility of the window surface

Inventive Principle:
Principle #24Intermediary (Mediator)

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 seamless extension and retraction of the screen without obstructing views, simplifies maintenance, and allows for easy installation and removal from existing frames, providing a versatile and functional solution for window and door openings.

Implementation Method 1

a tension adjustment arrangement that adjusts a tension in the cord

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

a first pulley located on the spindle, a second pulley, a third pulley located on an axis orthogonal to the spindle axis

Methodology Applied
Scientific EffectPulley: Pulley

Implementation Method 3

The cord is threaded through a guide assembly that includes a tension adjustment arrangement

Methodology Applied
Scientific EffectMechanical Advantage: Mechanical Advantage

Data Source

PatentEP3175073B1A retrofitable retractable screen system
Publication Date: 2020.08.26 SCREEN & BLIND TECH PTY LTD
  • EP3175073B1 patent drawingFigure 1A
  • EP3175073B1 patent drawingFigure 1B
  • EP3175073B1 patent drawingFigure 1C

AI summary

A retrofitable retractable screen system suitable for use with a range of windows or doors. Instead of using a spring based tensioning arrangements to rewind the screen onto the roller assembly, the arrangement uses a pulley located on the spindle, around which is wrapped a cord. A guide assembly guides the cord through or around a tension adjustment arrangement that adjusts the tension in the operative means as the screen is wound and unwound from the spindle to provide a smooth mechanism to extend and retract the screen. When the screen is extended, pushing the edge of the screen in order to force retraction of the screen is translated into a pulling action on the cord to unwind the cord off the first pulley, and this drives the rotation of the spindle to wind the screen back on. Conversely, pulling the distal edge to extend the screen rotates the spindle and pulley to wind the cord back onto the first pulley.