Dual-Drive Sun Curtain Position Detection

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Solution Overview

Problem

Existing sun protection systems with dual drives face challenges in safely switching off both primary and secondary drives at the retracted end position, particularly in emergency situations, due to high circuit complexity and mechanical wear issues with existing solutions, which can lead to damage and increased costs.

Innovation Solution

A common position sensor and evaluation unit detect the absolute curtain position independently of the activated motor, allowing safe shutdown of the secondary drive and optionally slowing down the primary drive, reducing mechanical wear and complexity by using a contactless, maintenance-free sensor system.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a mechanical limit switch is used to detect end position, then the drive can be switched off reliably, but mechanical wear occurs and the system becomes less reliable

Engineering Contradiction:
Improvedrive switch-off reliabilityVSAvoidmechanical component service life
Core Design Contradiction:
ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The patent replaces mechanical limit switches with a non-contact optical sensor system. The sensor detects the curtain's end position optically without mechanical contact, eliminating wear while maintaining reliable switch-off detection. This substitution directly resolves the contradiction between reliability and component durability.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If separate end position units are provided for both drives, then each drive can be switched off reliably, but the device complexity and cost increase

Engineering Contradiction:
Improvedrive switch-off reliabilityVSAvoidnumber of sensors and control units
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent implements a single optical sensor that serves both the primary and secondary drives. The sensor detects the curtain's position independently of which drive is active, and the control unit processes signals for both drives using this common sensor. This multi-functional approach eliminates the need for separate end position units while maintaining reliable switch-off for both drives, resolving the contradiction between reliability and complexity.

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

3Device complexity

If a torque shutdown system is used to switch off both drives, then the circuit complexity is reduced, but the shutdown reliability decreases

Engineering Contradiction:
Improvecontrol circuit complexityVSAvoiddrive switch-off reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent replaces the torque shutdown mechanism with an optical sensor-based detection system. The sensor accurately detects the curtain's end position without relying on torque thresholds, and the control unit processes this precise positional information to switch off both drives reliably. This substitution maintains low circuit complexity while significantly improving shutdown reliability compared to torque-based systems.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentEP2592211B1Sun protection system with two drive motors
Publication Date: 2015.01.21 WAREMA RENKHOFF SE
  • EP2592211B1 patent drawingFigure 1~3

AI summary

The sun protecting arrangement (10) has an adjustable curtain (26) with a primary drive (14) and a secondary drive (16). A control unit switches OFF the activated secondary drive in a retracted end position of curtain. The control unit includes common sensors to detect the changes in position of the curtain. An evaluation unit (34) determines the absolute position of curtain independent of primary and secondary drives, and brakes the secondary drive in retracted end position of curtain. USE : Sun protecting arrangement for shaded window and door opening. ADVANTAGE : The reliable detection of absolute position of curtain is ensured and the safe braking of secondary drive in retracted end position of curtain is achieved at less effort. Cost of sun protecting arrangement is reduced. DESCRIPTION OF DRAWINGS : The drawings show the perspective views of the sun protecting arrangement. 10 : Sun protecting arrangement 14 : Primary drive 16 : Secondary drive 26 : Curtain 34 : Evaluation unit.