Hot Drink Machine Drip Tray with Dual-Level Overflow Detection

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Solution Overview

Problem

Existing beverage preparation machines with drip trays often stop operation at inconvenient times due to overflow detection, lacking flexibility and increasing complexity and cost when trying to prevent liquid overflows during purging, rinsing, or cleaning cycles.

Innovation Solution

A hot drinks dispensing machine with a detection device that signals both intermediate and high liquid levels, allowing for user alerts and preventing overflow by continuing operation until the high level is reached, using a single measuring circuit and electrodes to detect these levels with reduced complexity and cost.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a detection device with only high level signal is used, then the machine stops operation when the drip tray is full to prevent overflow, but the machine stops at inopportune moments (e.g., during succession of drinks) reducing flexibility and productivity

Engineering Contradiction:
Improveoverflow preventionVSAvoiddrink preparation speed
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The liquid level detection is segmented into two distinct levels: an intermediate level (first level) and a high level (second level). The detection device includes a first electrode for detecting the intermediate level and a second electrode for detecting the high level, allowing the system to differentiate between warning conditions and critical stop conditions.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system implements feedback through two separate signals: an intermediate level signal that warns users to empty the drip tray soon, and a high level signal that triggers machine shutdown. This feedback mechanism allows users to take proactive action rather than being forced into reactive shutdowns during critical moments.

Inventive Principle:
Principle #23Feedback

2Ease of operation

If a detection device with intermediate and high level signals is used, then user flexibility is improved and overflow is prevented, but the device complexity increases

Engineering Contradiction:
Improveuser flexibilityVSAvoiddetection device complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The detection device merges multiple detection functions into a single integrated unit. The control circuit receives both intermediate and high level signals from the same detection device, which uses a single measuring circuit that alternately connects to different electrodes, reducing overall system complexity despite the multi-level detection capability.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

A single measuring circuit performs multiple functions by alternately connecting to different electrodes. The measuring circuit can detect both the intermediate level (via the first electrode) and the high level (via the second electrode), making one component serve multiple detection purposes and reducing the need for separate dedicated circuits for each level.

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

3Measurement precision

If two separate measuring circuits are used for intermediate and high level detection, then detection accuracy is improved, but the manufacturing cost and device complexity increase

Engineering Contradiction:
Improveliquid level detection accuracyVSAvoidmanufacturing cost
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

A single measuring circuit is designed to perform both intermediate level detection and high level detection by alternately connecting to the first electrode and second electrode respectively. This multi-functional approach maintains measurement precision for both levels while significantly reducing manufacturing cost compared to using two separate dedicated measuring circuits.

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

Solution Approach 2:

The measuring circuit operates by periodically alternating between connecting to the first electrode and the second electrode. This periodic switching allows the single circuit to sample both liquid levels sequentially, maintaining detection accuracy for both levels while using shared hardware resources to reduce cost.

Inventive Principle:
Principle #19Periodic 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

The machine provides user flexibility by allowing operation until the high liquid level is reached, preventing overflows and maintaining machine functionality without increasing complexity or cost, by alerting users to empty the drip tray at intermediate levels and blocking operation at high levels to prevent overflow.

Implementation Method 1

a measuring circuit, a first electrode arranged to detect the high level, a second electrode arranged to detect the intermediate level

Methodology Applied
Scientific EffectElectrical impedance measurement: Electrical Resistance

Data Source

PatentEP4193890B1Hot drink dispensing machine with drip tray
Publication Date: 2024.07.24 SEB SA
  • EP4193890B1 patent drawingFigure 1~2
  • EP4193890B1 patent drawingFigure 3

AI summary

A hot beverage dispensing machine comprising a hot beverage dispensing device (20) with at least one hot beverage dispensing nozzle, a drip tray (10) arranged under the dispensing nozzle, a control circuit, and a detection device that generates and transmits a high-level (HL) signal to the control circuit when the liquid filling the drip tray (10) reaches a high level (HL). The detection device generates and transmits an intermediate-level (IL) signal to the control circuit when the liquid filling the drip tray (10) reaches an intermediate level (IL), and the control circuit includes an alarm device to alert a user that the liquid is at the intermediate level (IL).