Drawer Drive Control Using Shaft Rotation Threshold Detection

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Solution Overview

Problem

Existing drawer opening and closing devices complicate the determination of manual operation force through acceleration measurements, which are vector quantities requiring direction and magnitude determination.

Innovation Solution

A device with a timer that starts a predetermined time interval upon detecting non-drive-generated revolutions, allowing for the determination of angular speed and enabling motor-driven constant speed operation of the drive shaft, eliminating the need for elaborate acceleration measurements and ensuring smooth, controlled drawer movement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If acceleration measurements are used to determine manual operation force, then the drawer movement can be detected, but the measurement complexity increases due to vector quantity determination

Engineering Contradiction:
Improvedrawer movement detectionVSAvoidacceleration measurement system
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts only the necessary information from the complex acceleration measurement - specifically, only the magnitude of acceleration is used, not the full vector quantity with direction. This simplifies the measurement system while still enabling drawer movement detection and force determination.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces complex mechanical acceleration sensors with a simpler sensor system that only measures acceleration magnitude. This substitution reduces device complexity while maintaining the ability to detect drawer movement and determine opening force.

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

2Loss of information

If acceleration vector determination is implemented, then complete motion information is obtained, but the control system complexity increases

Engineering Contradiction:
Improvemotion information completenessVSAvoidcontrol and regulation device
Core Design Contradiction:
Loss of informationVSDevice complexity

Solution Approach 1:

The control system extracts only the magnitude component from acceleration measurements, discarding the directional vector information. This extraction approach provides sufficient motion information for drawer control without requiring complex vector processing in the control system.

Inventive Principle:
Principle #2Taking out (Extraction)

3Object-affected harmful factors

If constant angular velocity is maintained, then safety and smooth operation are improved, but the ability to respond to variable user input is reduced

Engineering Contradiction:
Improveinjury risk and surprise effectsVSAvoidresponse to user operation
Core Design Contradiction:
Object-affected harmful factorsVSAdaptability or versatility

Solution Approach 1:

The system performs preliminary detection of user operation intent through acceleration magnitude measurement before initiating movement. The drive is activated only after detecting sufficient manual operation force, ensuring the system responds appropriately to user input while maintaining safe constant velocity during actual movement.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system dynamically adjusts between two operational modes: detection mode (variable acceleration during manual operation) and execution mode (constant angular velocity during motorized movement). This dynamic switching allows the system to respond to user input while maintaining safety during automated operation.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP1934424B1Device and method for closing or opening and closing at least one drawer, flap
Publication Date: 2016.03.16 GRASS GMBH
  • EP1934424B1 patent drawingFigure 1
  • EP1934424B1 patent drawingFigure 2

AI summary

Disclosed is a device for moving and/or opening and closing at least one drawer, flap, door, or similar. Said device comprises at least one drive unit (9) that is effectively connected to the drawer, flap, door, or similar, at least one control and regulation unit (1) for the at least one drive unit (9), and at least one sensor unit (2) for detecting the direction of rotation and/or the number of rotations of the drive shaft of the drive unit (9), said number and/or said direction of rotation being fed to the control and regulation unit (1). A timer (5) is provided that starts a given interval when rotations of the drive shaft are detected which are not generated by the drive unit (9) while at least one comparing unit (3, 4) is provided in which a lower threshold value can be stored for the rotations or partial rotations of the drive shaft detected by the sensor unit (2) within the given interval. The drive unit (9) can be activated so as to open or close the at least one drawer, flap, door, or similar when the lower threshold value is exceeded.