Coffee Grinder Force-Controlled Grinding Gap for Thermal Compensation

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Solution Overview

Problem

Conventional coffee grinders face challenges in precisely setting the degree of fineness due to manufacturing accuracy issues and disruptive influences like thermal expansion and grinding disc wear, leading to fluctuating extraction times and the need for lengthy adjustment cycles.

Innovation Solution

A grinder with a force-generating device that applies an adjustable force to the grinding tools, allowing for precise control of the grinding gap and enabling automatic adjustment of the degree of grinding based on coffee type, using force sensors and a control unit to maintain a product-specific optimal setting.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional geometry-based adjustment mechanisms are used to change the grinding gap, then the degree of grinding can be adjusted, but manufacturing accuracy issues and thermal expansion cause fluctuating extraction times and require lengthy adjustment cycles

Engineering Contradiction:
Improvegrinding gap precisionVSAvoidadjustment cycle time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The patent replaces conventional mechanical geometry-based adjustment mechanisms with a force-generating device that applies controlled forces to the grinding tools. This substitution allows precise control of the grinding gap through force application rather than mechanical positioning, eliminating the need for lengthy adjustment cycles and compensating for thermal expansion and wear effects in real-time

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

Solution Approach 2:

The patent changes the control parameter from geometric positioning to force application. By controlling the magnitude and direction of forces applied to the grinding tools, the system can precisely adjust the grinding gap and compensate for various disruptive influences, achieving both high precision and rapid adjustment

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If multiple grinders are used in fully automatic coffee machines to handle different coffee types, then product-specific grind settings can be maintained, but the device complexity and cost increase

Engineering Contradiction:
Improveproduct-specific grind setting capabilityVSAvoidnumber of grinders
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent makes the grinding system dynamic by introducing a force-generating device that can rapidly adjust the grinding parameters in response to different coffee types. This dynamic adjustment capability allows a single grinder to replace multiple fixed-setting grinders, maintaining product-specific grind settings while reducing device complexity

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The force-generating device enables a single grinder to perform multiple functions by adapting to different coffee types and grind requirements. The system can be quickly reconfigured through force control to handle various products, eliminating the need for multiple dedicated grinders

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

3Loss of time

If the grinding gap is reduced to achieve finer grind, then the extraction time decreases, but the contact pressure increases and may cause compaction issues

Engineering Contradiction:
Improveextraction timeVSAvoidcontact pressure
Core Design Contradiction:
Loss of timeVSStress or pressure

Solution Approach 1:

The patent changes the control approach from purely geometric gap adjustment to force-controlled grinding. By controlling the forces applied to the grinding tools, the system can achieve fine grinds while managing contact pressure through force balance, preventing compaction issues that would result from simple gap reduction

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 solution allows for quick and precise adjustment of the grinding degree, compensating for thermal expansion and wear, ensuring consistent extraction times and flavor profiles, potentially eliminating the need for multiple grinders in fully automatic coffee machines.

Implementation Method 1

a force-generating device (15) for applying a force F, which can preferably also be adjusted during operation, to the first grinding tool (2) or the second grinding tool (8), with the force F being directed in such a way that it pushes the respective grinding tool, which is acted upon by the force F, in the direction of the other grinding tool

Methodology Applied
Scientific EffectMechanical Force: Mechanical Force

Implementation Method 2

The grinder also has at least one force measuring device with at least one force sensor, with the at least one force sensor being directly or indirectly connected to the grinding tool

Methodology Applied
Scientific EffectForce sensing: Force

Implementation Method 3

The rotating movement of one grinding tool pulls the beans into a grinding gap and grinds finer and finer over the narrowing grinding gap width

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 4

a force-generating device (15) for applying a force F... which pushes the respective grinding tool, which is acted upon by the force F, in the direction of the other grinding tool

Methodology Applied
Scientific EffectCompression: Compression

Data Source

PatentEP3813614B1Grinder, coffee machine and method for grinding coffee beans
Publication Date: 2022.08.31 MELITTA PROFESSIONAL COFFEE SOLUTIONS GMBH & CO
  • EP3813614B1 patent drawingFigure 1
  • EP3813614B1 patent drawingFigure 2
  • EP3813614B1 patent drawingFigure 3

AI summary

The invention relates to a grinder (1) for grinding coffee beans (5), wherein the grinder (1) has a first grinding tool (2) and a second grinding tool (8), which form a grinding gap (14), wherein the second grinding tool (8) is rotatable relative to the first grinding tool (2), characterized in that the grinding tool (1) has at least one force generation device (15) for applying a force F, which is also adjustable during operation, to the first grinding tool (2) or second grinding tool (8), and which can be transferred to the coffee beans, and a method for grinding coffee beans for preparing a caffeinated hot beverage.