Coffee Grinder Load-Cell Feedback for Accurate Dose Control
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Solution Overview
Problem
Existing coffee grinders with automatic dose control systems face inaccuracies in dosing due to variable 'time-of-flight' which depends on grain size and mechanical/electronic factors, leading to errors in coffee dispensing.
Innovation Solution
A coffee grinder with a load cell and control unit that adjusts the tare weight with a correction factor and allows for extra-dose dispensing based on user-defined error limits, ensuring accurate dosing regardless of grain size and mechanical structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the grinder is stopped in advance to account for time-of-flight, then the coffee dose amount is controlled, but the dosing accuracy deteriorates due to variable time-of-flight depending on grain size and mechanical structure
Solution Approach 1:
The system continuously monitors the actual weight of ground coffee during dispensing using a load cell and compares it with the target dose weight. The control unit adjusts the grinder operation in real-time based on this feedback, eliminating the need for fixed time-of-flight calculations and achieving accurate dosing regardless of grain size or mechanical variations.
Solution Approach 2:
The patent replaces the mechanical/time-based dosing method (fixed time-of-flight calculation) with an electronic measurement and control system. The load cell provides continuous weight measurements, and the control unit processes this data to dynamically adjust dispensing, substituting the inadequate mechanical timing approach with a precise electronic control system.
2Loss of time
If the load cell is calibrated to a lower weight to account for time-of-flight, then the time-of-flight is considered, but the dosing accuracy deteriorates due to incorrect calculation for different coffee types
Solution Approach 1:
The system transitions from a static, pre-calibrated time-of-flight approach to a dynamic, real-time measurement system. The load cell continuously measures the actual weight during dispensing, and the control unit dynamically adjusts the grinding process based on current conditions, adapting to different coffee types and grain sizes without requiring recalibration.
Solution Approach 2:
The continuous weight feedback from the load cell allows the system to monitor and adjust the dispensing process in real-time. This feedback mechanism eliminates the need for inaccurate pre-calculated time-of-flight compensation and enables precise dosing adaptation to varying coffee characteristics.
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 solution provides accurate and reliable automatic dose control, ensuring the coffee dose is precise and consistent, maintaining coffee quality within acceptable error limits.
Implementation Method 1
a load cell (6) connected to the support (4) to weigh the coffee powder inside the filter holder (5)
Data Source
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AI summary
A coffee grinder (100) comprises an automatic coffee dose control system that provides for comparing a difference between an ideal weight (PID) set by a user and an actual weight (PM) measured by a load cell (6) with an error (ERR); if the difference between the ideal weight (PID) and the actual weight (PM) is greater than the error (ERR), an extra-dose of coffee powder is dispensed.