Screening Body Position Detection Using Spring Tension

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Solution Overview

Problem

Existing screening devices face issues with sagging and wrinkling of the screening body during operation, leading to potential damage and jamming of the driving mechanism, and an aesthetically unpleasing appearance in the fully extended position, due to inaccurate detection of the fully extended position.

Innovation Solution

A method involving an electric motor, tachometer, and control unit to automatically determine the fully extended position by measuring the number of revolutions of the roller tube under varying tension levels, ensuring the screening body is properly extended and preventing sagging or wrinkling, which includes rotating the roller tube to tension spring elements, stopping at a breaking current, measuring revolutions, and calculating a value to denote the fully extended position.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the screening body is extended using prior art methods with learning processes and torque threshold detection, then the fully extended position can be detected, but the screening body sags and wrinkles during operation, leading to inaccurate detection

Engineering Contradiction:
Improvedetection accuracy of fully extended positionVSAvoidscreening body sagging and wrinkling
Core Design Contradiction:
Measurement precisionVSShape

Solution Approach 1:

The patent applies preliminary action by pre-tensioning the screening body using spring elements before detecting the fully extended position. The method involves extending the screening body beyond the actual fully extended position, then using the spring elements to pull it back, ensuring proper tension is established before position detection occurs. This prevents sagging and wrinkling during the detection process.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent changes the tension parameter of the screening body by using spring elements that apply a predetermined tension force. The system measures the number of revolutions required to achieve the fully extended position under this controlled tension, ensuring accurate detection. The spring elements maintain consistent tension parameters throughout the operation, preventing variations that cause sagging.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If the screening body is extended using prior art methods with multiple learning operations, then position detection is attempted, but the process is excessively cumbersome and time-consuming

Engineering Contradiction:
Improvedetection accuracy of fully extended positionVSAvoidtime required for learning process
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent performs the tensioning action in advance by extending the screening body beyond the fully extended position and using spring elements to pull it back to the correct position before detection. This preliminary preparation ensures that when detection occurs, the screening body is already in the correct tensioned state, eliminating the need for multiple learning operations and reducing time loss.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent skips the time-consuming multiple learning operations of prior art by directly extending the screening body beyond the fully extended position, applying spring tension, and immediately performing detection. This rushes through the preparation phase in a single operation rather than requiring multiple iterative learning cycles.

Inventive Principle:
Principle #21Skipping (Rushing through)

3Measurement precision

If the screening body is extended using prior art methods with current threshold detection, then position detection is attempted, but the appearance in fully extended position becomes aesthetically unpleasing

Engineering Contradiction:
Improvedetection accuracy of fully extended positionVSAvoidaesthetic appearance of screening body
Core Design Contradiction:
Measurement precisionVSShape

Solution Approach 1:

The patent applies preliminary action by pre-tensioning the screening body with spring elements before detecting the fully extended position. This ensures the screening body is properly tensioned and free of sagging or wrinkles at the moment of detection, guaranteeing both accurate detection and aesthetically pleasing appearance in the fully extended position.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent changes the tension parameter by introducing spring elements that apply a predetermined tension force to the screening body. This controlled tension parameter ensures the screening body maintains its proper shape and aesthetic appearance during detection, preventing the sagging and wrinkling that occurs with uncontrolled tension in prior art methods.

Inventive Principle:
Principle #35Parameter changes

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

This method ensures smooth operation and an aesthetically pleasing appearance by accurately determining the fully extended position, preventing sagging and wrinkling, and allowing for correct retraction and extension of the screening body.

Implementation Method 1

an electric motor connected to and adapted for rotating the roller tube, the first spring element and the second spring element such as to drive the screening body between a fully retracted position

Methodology Applied
Scientific EffectElectromagnetic conversion: Electromagnetic Induction

Implementation Method 2

the electric motor comprising a tachometer

Methodology Applied
Scientific EffectTachometer measurement: Electromagnetic Induction

Implementation Method 3

a first end section comprising a first spring element and a second end section comprising a second spring element, the first spring element and the second spring element such as to drive the screening body between a fully retracted position

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP3483380B1A method for determining a fully extended position of a screening body of a screening device
Publication Date: 2020.09.23 VKR HOLDING AS
  • EP3483380B1 patent drawingFigure 1
  • EP3483380B1 patent drawingFigure 2~4
  • EP3483380B1 patent drawingFigure 5

AI summary

A method for determining a fully extended position of a screening body (14) of a screening device (12) for a roof window. The screening device (12) comprises a control unit comprising a data storage device, an electric motor (18) comprising a tachometer (181), a roller tube (15), a screening body (14) and a first and a second spring element (164, 174). The method comprises the steps of driving the screening body (14) from a fully retracted position to a fully extended position, in which the spring elements (164, 174) are tensioned to a first tension level, T1, stopping the electric motor (18) at a point at which the spring elements (164, 174) are tensioned to a second tension level, T2, above the first tension level, T1, measuring the number of revolutions, Rd, of the roller tube (15) necessary to drive the screening body (14) to the said position at which the motor (18) is stopped, storing the measured number of revolutions, Rd, in the data storage device, measuring the number of revolutions, Rb, of the roller tube, that a release of a tension corresponding to the difference, ΔT, between the first tension level, T1, and the second tension level, T2, will cause the roller tube (15) to move back towards the fully retracted position, storing the number of revolutions, Rb, in the data storage device, and calculating and storing in the data storage device a value R = Rd - Rb.