Cooking Vessel Liquid Level Sensing With an Open Swiveling Lid

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Solution Overview

Problem

Existing cooking appliances require the lid to be closed to measure the liquid level, limiting their universal use and complicating cleaning and maintenance, especially in applications where the lid is often open.

Innovation Solution

Attaching at least part of the non-contact measuring device to the lid allows for liquid level detection when the lid is open, using a reflector to direct radiation between the emitter and sensor, which can be positioned on the outside or inside of the lid, enabling measurement without internal components, thus facilitating easier access and cleaning.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the measuring device is attached to the inside of the container, then the liquid level can be measured, but the cleaning and maintenance becomes difficult and the inner wall cannot be smooth and undercut-free

Engineering Contradiction:
Improveliquid level measurementVSAvoidcleaning and maintenance
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The measuring device is extracted from the interior of the container and attached to the exterior surface. This allows the interior to remain smooth and undercut-free for easy cleaning, while the measuring device performs its function from the outside, eliminating the contradiction between measurement capability and ease of maintenance.

Inventive Principle:
Principle #2Taking out (Extraction)

2Measurement precision

If the lid must be closed to measure liquid level, then the measurement can be performed, but the appliance cannot be used universally for processes requiring open lid

Engineering Contradiction:
Improveliquid level detectionVSAvoidcooking process flexibility
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The measuring device is designed to function with the lid in any position (open, closed, or partially open) by attaching it to the exterior of the lid. This allows the appliance to maintain liquid level measurement capability while accommodating various cooking processes that require different lid positions, achieving universal applicability.

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

3Area of stationary object

If the measuring device is positioned away from the pivot axis, then the measurement range is increased, but the movement distance increases making measurement less stable

Engineering Contradiction:
Improvemeasurement coverageVSAvoidmeasurement stability
Core Design Contradiction:
Area of stationary objectVSStability of the object's composition

Solution Approach 1:

The system compensates for the increased movement distance of the measuring device by dynamically adjusting measurement parameters such as the angle of incidence and detection thresholds. This allows the device to maintain measurement stability even when positioned away from the pivot axis to increase measurement coverage.

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

Enables universal use of cooking appliances by allowing liquid level measurement with the lid open, improving maintenance and cleaning efficiency, and enabling precise portioning during cooking processes like pasta cooking without the need to close the lid.

Implementation Method 1

a non-contact measuring device for determining the liquid level in the pan... which was reflected on the liquid surface

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 2

Another embodiment that is optimized in terms of maintenance and loading of the measuring device provides for attaching a reflector to the cover. This reflector reflects a measuring beam coming to and/or from the liquid surface.

Methodology Applied
Scientific EffectReflection: Reflection

Data Source

PatentEP2633790B1Cooking device and method for measuring the liquid level in a cooking device
Publication Date: 2014.06.25 RATIONAL AG
  • EP2633790B1 patent drawingFigure 1~2
  • EP2633790B1 patent drawingFigure 3~4

AI summary

The appliance has a crucible (10) that is filled with a liquid e.g. oil, and a swiveling lid (18) that is utilized to close the crucible. A contactless measurement device is utilized for measuring a level of the liquid in the crucible. A part of the contactless measurement device is mounted on the lid such that the measurement device captures the level of the liquid when the lid is open. The measurement device is arranged with a transmitter (24) and a sensor (26) is arranged on the lid. A set of reflectors is mounted on the lid. An independent claim is also included for a method for measurement of a level of liquid in a crucible of a cooking appliance.