Espresso Brewing Chamber Flowmeter Control for Grind Dose Consistency
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Solution Overview
Problem
Existing infusion devices for espresso-type coffee machines are complex and costly due to the use of sophisticated sensors and bulky components to measure the quantity of ground coffee, which are prone to breakdowns and difficult to maintain, especially in a humid environment.
Innovation Solution
An infusion device with a hydraulic drive mechanism and a flowmeter to measure the volume of hydraulic fluid injected into the infusion chamber, allowing the control circuit to determine the height of the compacted grind cake, thereby controlling the quantity of ground coffee with a simple and economical design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If sophisticated sensors (optical sensors, Hall effect sensors) are used to measure the packing position of the piston, then measurement precision is improved, but device complexity and cost increase, and reliability decreases due to sensitivity to dirt and breakdowns
Solution Approach 1:
The patent extracts the measurement function from complex sensors and implements it through a simple counter that counts revolutions of the motor driving the presser piston. This eliminates sophisticated sensors while maintaining measurement capability through a basic rotational counting mechanism.
Solution Approach 2:
The patent replaces expensive, sophisticated sensors with a simple, inexpensive counter mechanism that counts motor revolutions. This simple component is more reliable and less sensitive to environmental factors like dirt, effectively using a 'cheaper' solution that is more robust in the espresso machine environment.
2Measurement precision
If rotary potentiometers are used to measure the packing position of the presser piston, then measurement capability is achieved, but device complexity and cost increase, and the component is bulky and difficult to arrange
Solution Approach 1:
The patent extracts the measurement function from the bulky rotary potentiometer and implements it through a simple counter that counts the revolutions of the motor driving the presser piston. This eliminates the need for a separate potentiometer component while maintaining the ability to measure piston position.
Solution Approach 2:
The motor that drives the presser piston is given a dual function: it both moves the piston and serves as the measurement reference through its revolution counting. This eliminates the need for a separate measurement component, making the system more compact and less complex.
3Device complexity
If the quantity of grind is controlled by grinding wheel drive time, then simplicity is maintained, but manufacturing precision decreases due to variations from wheel wear and bean hardness
Solution Approach 1:
The patent implements feedback by measuring the actual packing position of the presser piston and using this information to adjust the grinding time. The counter records how many revolutions the motor makes to achieve the target packing position, and this data is used to correct variations in grind quantity caused by wheel wear or bean hardness differences.
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 provides precise control over the quantity of ground coffee, ensuring repeatable results for different beverage types while being economical and reliable, with a calibration mechanism that uses standard components and is resistant to environmental pollutants.
Implementation Method 1
a flowmeter to measure the volume of hydraulic fluid injected into the drive mechanism
Implementation Method 2
a hydraulic drive mechanism for the pressing piston comprising a hydraulic pump
Data Source
Figure 1
Figure 2
Figure 3~6
AI summary
- The invention relates to a brewing device (2) for an espresso-type coffee machine comprising a brewing chamber (12) for receiving ground coffee, a press piston (13) movably mounted over a stroke extending between a high and a low tamping position, in which it penetrates said brewing chamber (12) to form a compacted puck of ground coffee, a hydraulic drive mechanism for the press piston (13) comprising a hydraulic pump (18) and means for measuring the volume (9) of hydraulic fluid injected into the drive mechanism. - According to the invention, the brewing device (2) comprises a control circuit (3) determining the height of the compacted puck of ground coffee from the signals delivered by the volume measuring means (9) during the stroke of the press piston (13).