Coffee Grinder-Doser Self-Calibration for Dose Weight Precision

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Solution Overview

Problem

Conventional grinder-doser apparatuses for espresso coffee are inefficient in achieving precise and automatic calibration of coffee dose weights due to sensitivity issues with weighing devices during grinding, leading to imprecise and labor-intensive calibration processes that are unsuitable for high-frequency professional use.

Innovation Solution

A method for instantaneous self-calibration that includes setting nominal dose weights and tolerance/reliability ranges, with automatic control and recalculation of grinding times using electronic weighing means and a granulometry adjusting mechanism, allowing continuous and autonomous calibration during operation, ignoring anomalous values and considering granulometry variations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional weighing devices are used during grinding, then dose weight can be measured, but measurement precision deteriorates due to sensitivity issues and vibrations during grinding

Engineering Contradiction:
Improvedose weight measurement precisionVSAvoidweighing device reliability during grinding
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The system performs weighing operations periodically at specific moments when grinding has ceased, rather than continuously during grinding. The microprocessor controls the weighing cycle to occur after grinding stops, when vibrations have subsided, ensuring accurate measurement without interference from grinding vibrations.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The system prepares for weighing by first stopping the grinding operation and allowing vibrations to settle before initiating the measurement. This preliminary action ensures that the weighing device is in a stable state before dose weight measurement begins, eliminating measurement errors caused by vibrations.

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If manual calibration methods are used, then dose weight can be adjusted, but productivity deteriorates due to labor-intensive and time-consuming calibration processes

Engineering Contradiction:
Improvedose weight calibration precisionVSAvoidcalibration process efficiency
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The system performs automatic self-calibration using its own integrated weighing device and microprocessor control. The microprocessor automatically adjusts grinding time parameters based on measured dose weights, eliminating the need for manual intervention and external calibration tools, thereby improving both precision and productivity.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system implements a feedback loop where the weighing device measures actual dose weight, the microprocessor compares it with target values, and automatically adjusts grinding time parameters accordingly. This closed-loop control system continuously refines calibration without manual intervention, achieving high precision efficiently.

Inventive Principle:
Principle #23Feedback

3Ease of operation

If grinding time is fixed, then operation is simple, but manufacturing precision deteriorates as actual dispensed dose varies with environmental conditions and wear

Engineering Contradiction:
Improvegrinder operation simplicityVSAvoiddispensed dose weight precision
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The system transitions from fixed grinding time to dynamic, adjustable grinding time controlled by the microprocessor. The microprocessor modifies grinding time parameters in real-time based on feedback from the weighing device, environmental sensors, and wear detection, maintaining precise dose weight while adapting to changing conditions.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system automatically changes the grinding time parameter based on measured dose weight deviations, environmental conditions, and component wear. The microprocessor adjusts this critical parameter dynamically to compensate for variations and maintain manufacturing precision without affecting operational simplicity.

Inventive Principle:
Principle #35Parameter changes

4Manufacturing precision

If periodic manual calibration is performed, then dose accuracy can be maintained, but loss of time increases due to interruptions in high-frequency professional use

Engineering Contradiction:
Improvedose weight accuracyVSAvoidcalibration interruption time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The system performs calibration continuously and automatically during normal operation rather than requiring periodic interruptions. The microprocessor manages calibration cycles that occur during low-demand periods or between uses, maintaining dose accuracy without stopping workflow and eliminating time loss from manual calibration interruptions.

Inventive Principle:
Principle #20Continuity of useful action

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 continuous correct grinding times, reduces out-of-tolerance doses, minimizes operator intervention, and maintains coffee quality by automatically adapting to granulometry changes, thus improving precision and efficiency in coffee dosing.

Implementation Method 1

automatic control of the weight of each actually dispensed dose

Methodology Applied
Scientific EffectGravitation: Gravitation

Data Source

PatentEP3560399B1Method for the instantaneous self-calibration of the dose for a coffee grinder-doser apparatus
Publication Date: 2021.01.27 FIORENZATO M C
  • EP3560399B1 patent drawingFigure 1
  • EP3560399B1 patent drawingFigure 2~4c
  • EP3560399B1 patent drawing

AI summary

Method (10) for the instantaneous self-calibration of the dose of coffee, for a grinder-doser apparatus (20) with electronic control (203, 204, LCF, LCO) provided with a weighing means (205, 206) and with a granulometry adjusting means (214, 215) with a warning microswitch (216). The method provides: a first setting (101) of the nominal dose with temporary grinding times (TS, TD); a second setting of the tolerance (106) and reliability (107a, 107b) ranges of the dispensed doses, for the purpose of recalculation; the automatic control (103) of the weight of each actually dispensed dose; the automatic recalculation (104) of the grinding times according to an ordinary calculation logic (204, LCO), when one detects three consecutive out-of-tolerance doses all within the positive or negative reliability range, or according to a forced calculation logic (204, LCF) when the microswitch (216) detects a granulometry variation; automatic calibration (105, TS, TD) of the apparatus according to the recalculated times (TS, TD).