Household Door Opener With Variable Rack-and-Pinion Force Transfer

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Solution Overview

Problem

Household appliance door opening mechanisms face challenges in overcoming initial resistance, such as door locks and magnetic seals, requiring varying force levels, which existing actuator mechanisms often address by using oversized motors, compromising speed and user comfort.

Innovation Solution

A variable power transmission mechanism between the electric motor and the coupling part allows for different path speeds, adapting to non-uniform force requirements by changing gear configurations along the range of motion, enabling quick door opening without an oversized motor.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If an oversized electric motor is used to overcome initial resistance, then the force capability is improved, but the opening speed and user comfort deteriorate

Engineering Contradiction:
Improveforce capabilityVSAvoidopening speed
Core Design Contradiction:
ForceVSSpeed

Solution Approach 1:

The patent applies a variable transmission ratio mechanism that dynamically adjusts the force and speed characteristics during the door opening process. The transmission ratio changes as a function of the coupling element's position, providing high force at the beginning (to overcome initial resistance) and higher speed later in the movement, thus resolving the contradiction between force capability and opening speed without requiring an oversized motor.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention changes the transmission ratio parameter throughout the operating range. By using a transmission mechanism where the ratio between input and output speeds/forces varies continuously or in stages based on position, the system optimizes both force delivery and speed performance across different phases of door opening, eliminating the need for excessive motor power while maintaining high opening speed.

Inventive Principle:
Principle #35Parameter changes

2Device complexity

If a constant transmission ratio is used, then the device complexity is reduced, but the ability to adapt to varying force requirements deteriorates

Engineering Contradiction:
Improvetransmission mechanism complexityVSAvoidadaptability to force requirements
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent implements a transmission mechanism with variable transmission ratio that adapts to varying force requirements during door opening. The ratio changes based on the coupling element's position, providing high force multiplication when needed (at the beginning of movement) and lower ratio later, thereby achieving adaptability without excessive complexity through a well-designed mechanical or electromechanical transmission system.

Inventive Principle:
Principle #15Dynamics

3Force

If high force is applied throughout the entire opening process, then the initial resistance is overcome, but the energy consumption increases

Engineering Contradiction:
Improveforce applicationVSAvoidenergy consumption
Core Design Contradiction:
ForceVSUse of energy by moving object

Solution Approach 1:

The invention changes the transmission ratio parameter throughout the operating range to optimize energy consumption. By providing high force multiplication only when necessary (during the initial phase when resistance is highest) and reducing the effective force transmission ratio in later phases, the system minimizes energy consumption while still successfully overcoming initial resistance and completing the door opening motion.

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

The actuator mechanism ensures user comfort by quickly opening doors while maintaining efficient energy use, adapting force application to overcome initial resistance and maintain speed throughout the opening process.

Implementation Method 1

an electric motor, a coupling part that can be driven by the electric motor within a limited range of motion, in particular linearly

Methodology Applied
Scientific EffectElectromagnetic conversion: Electromagnetic Induction

Implementation Method 2

a force transmission mechanism between the electric motor and the coupling part

Methodology Applied
Scientific EffectMechanical force transmission: Mechanical Force

Implementation Method 3

for coupling with the movable component in a thrust- and/or tension-transmitting manner

Methodology Applied
Scientific EffectThrust and tension: Tension

Data Source

PatentEP4438920A1Actuator mechanism for an object of domestic equipment
Publication Date: 2024.10.02 EMZ HANAUER GMBH & CO KGAA
  • EP4438920A1 patent drawingFigure 1
  • EP4438920A1 patent drawingFigure 2~3
  • EP4438920A1 patent drawingFigure 4

AI summary

Exemplary embodiments of the invention provide a door opener (18) for a household electrical appliance. The door opener comprises an electric motor (30) and a push button (36) driven by the electric motor for pressing action against the door of the electrical appliance. A force transmission mechanism (32) is provided between the electric motor and the push button, which is capable of ensuring a variable linear speed of the push button at a constant speed of the electric motor. Certain embodiments provide for this purpose a multi-stage rack and pinion drive, which is formed by a gear ring (42) and a rack (38) that can transmit the driving force of the electric motor to the push button via various gear pairs that can be alternately meshed.