Motorized Curtain Carriage With Variable Friction Wheel Loading

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Solution Overview

Problem

Existing motorized curtain systems face inefficiencies in energy consumption due to the need for oversized motors to handle varying curtain masses during opening and closing, as the force required changes significantly throughout the movement, leading to poor performance and high energy consumption, especially when powered by autonomous sources.

Innovation Solution

A motorized curtain carriage with an adjustable pressing means that varies the contact force between the friction wheel and the rail based on the evolving load, allowing the friction wheel to be positioned closer to the rail and adjusting the spacing of guide wheels to match the changing mass of the curtain, optimizing energy consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the motor is dimensioned to tow the curtain at the end of its travel, then the motor can close the curtain, but the motor is oversized at the start of closing resulting in poor performance and high energy consumption

Engineering Contradiction:
Improveability to close curtainVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The pressing means is designed to dynamically adjust the contact force between the friction wheel and the rail based on the evolving load during curtain movement. The contact force increases as the curtain mass increases during closing, and decreases when opening, allowing the motor to operate at optimal power levels throughout the cycle rather than being constantly oversized.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the physical parameter of contact force between the friction wheel and rail according to the operational phase. By varying this parameter in response to load conditions (curtain mass being moved), the motor can maintain efficient operation across different stages of curtain opening and closing.

Inventive Principle:
Principle #35Parameter changes

2Force

If the contact force between the friction wheel and the rail is increased to handle maximum load, then the motor can tow the full curtain mass, but the energy consumption increases during low load phases

Engineering Contradiction:
Improvetowing forceVSAvoidenergy waste
Core Design Contradiction:
ForceVSLoss of energy

Solution Approach 1:

The pressing means dynamically modulates the contact force between the friction wheel and rail according to the actual load being moved. During closing, as more curtain mass is towed, the contact force increases accordingly. During opening, when pushing lighter loads, the contact force decreases, preventing energy waste from excessive friction.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system incorporates feedback through the pressing means that responds to the evolving load conditions during curtain movement. The contact force is automatically adjusted based on the mass being moved, creating a self-regulating mechanism that optimizes energy usage while maintaining sufficient towing force when needed.

Inventive Principle:
Principle #23Feedback

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 solution ensures consistent energy usage by adjusting the contact force according to the curtain's mass, reducing motor strain and optimizing energy efficiency, particularly in autonomous systems.

Implementation Method 1

a friction wheel (140) which is in contact with a rolling surface (53, 54) of the rail (50) and exerts on this surface a contact force

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP2590538B1Driving carriage for a motorized curtain and occultation device with such a driving carriage
Publication Date: 2018.07.04 SOMFY ACTIVITES SA
  • EP2590538B1 patent drawingFigure 1~3
  • EP2590538B1 patent drawingFigure 4~6
  • EP2590538B1 patent drawingFigure 7~8

AI summary

This motorized carriage (100b) for opening/closing a screen moves along a rail (50) by means of a friction wheel (140b) that is rotated by a motor and is in contact with at least one running surface (53, 54) of the rail. The contact force (FT) between the friction wheel (140b) and the running surface can be regulated by a presser means (164b) that enables the contact force (FT) to be varied according to a resistive force (RT) that depends on the load pulled or pushed by the carriage (100b) as it moves (F1).