Pressure Cooker Lid Venting for Controlled Overpressure Release

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Solution Overview

Problem

Conventional pressure cooking appliances face issues with accidental overpressure due to deficient safety valves, leading to potential user injury from steam projection and difficulties in maintenance and cleaning, while existing safety mechanisms can be unreliable and complex.

Innovation Solution

A pressure cooking appliance design featuring a seal that deforms to release excess pressure through a controlled opening, preventing steam from directly reaching the user and allowing easy maintenance, with a bayonet locking system and a cover element that moves to expose or mask the opening for safety and accessibility.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If an orifice is made through the lid for steam leakage, then depressurization function is improved, but risk of steam projection towards user increases

Engineering Contradiction:
Improvedepressurization functionVSAvoidsteam projection risk
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

A cover element is introduced as an intermediary component between the orifice and the external environment. This cover element can move to either cover the orifice (preventing steam projection) or uncover the orifice (allowing depressurization), thus mediating between the conflicting requirements of safety and functionality.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The cover element is designed to be movable rather than fixed, allowing it to dynamically switch between covering and uncovering the orifice. This dynamic capability enables the system to adapt between two operational states: safe state (covered) and depressurization state (uncovered), resolving the contradiction between safety and depressurization functionality.

Inventive Principle:
Principle #15Dynamics

2Reliability

If an orifice is made through the lid for safety depressurization, then safety function is improved, but accessibility for maintenance and cleaning deteriorates

Engineering Contradiction:
Improvesafety functionVSAvoidmaintenance accessibility
Core Design Contradiction:
ReliabilityVSEase of repair

Solution Approach 1:

The movable cover element allows the orifice to be easily accessed when needed for maintenance or cleaning. By simply moving the cover element to the uncovered position, the orifice becomes accessible without requiring disassembly of the lid or complex maintenance procedures, thus improving ease of repair while maintaining safety functionality.

Inventive Principle:
Principle #15Dynamics

3Power

If a conventional safety valve is used, then depressurization capability is improved, but reliability of safety function deteriorates due to ageing and fouling

Engineering Contradiction:
Improvedepressurization capabilityVSAvoidsafety function reliability
Core Design Contradiction:
PowerVSReliability

Solution Approach 1:

The invention extracts the depressurization function from the conventional safety valve mechanism and implements it through the seal's natural deformation properties. By removing the complex valve mechanism and its associated maintenance issues (ageing, fouling, clogging), the system achieves depressurization capability through a simpler, more reliable mechanism that uses the seal's inherent elasticity to open orifices when pressure exceeds predetermined thresholds.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The seal automatically performs the depressurization function through its own deformation properties when overpressure occurs. The seal's natural elasticity causes it to deform and open the orifices without requiring any external actuation or complex mechanical components, making the system self-regulating and highly reliable.

Inventive Principle:
Principle #25Self-service

4Reliability

If the seal is used as additional safety means with natural deformation properties, then safety function is improved, but control over depressurization precision deteriorates

Engineering Contradiction:
Improvesafety functionVSAvoiddepressurization pressure threshold
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The seal is designed with non-uniform thickness, creating localized thin zones at specific positions. These thin zones have lower deformation resistance and deform first when pressure increases, allowing precise control over the pressure threshold for opening each orifice. This local variation in seal geometry enables precise control of depressurization timing while maintaining the overall reliability of the safety function.

Inventive Principle:
Principle #3Local quality

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

Ensures reliable and controlled depressurization in case of overpressure, reduces the risk of steam injury, and simplifies maintenance and cleaning by providing easy access to the pressure regulation mechanism.

Implementation Method 1

the natural deformation properties of the seal under the effect of the prevailing overpressure. in the enclosure, which overpressure will move the seal out of its sealing position to allow steam to escape

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP3238580B1Pressure cooker provided with a lid opening
Publication Date: 2018.10.03 SEB SA
  • EP3238580B1 patent drawingFigure 1~4
  • EP3238580B1 patent drawingFigure 5~12
  • EP3238580B1 patent drawingFigure 13~14

AI summary

- Pressure cooker provided with a lid opening. - The invention relates to an appliance (1) for cooking food under pressure comprising: - a tank (2) and a cover (3) intended to form with said tank (2) a cooking enclosure, - a sealing (4) interposed between the lid (3) and the tank (2) to allow the pressure rise of the cooking enclosure, - an opening (10) formed through the lid (3) facing said gasket seal (4), characterized in that it also comprises a cover element (12), said cover (3) and cover element (12) being mounted so as to move relative to each other to move between a first configuration in which the cover element (12) caps said opening (10) to hide it and a second configuration in which the cover element (12) uncovers said opening (10), the latter thus being accessible from the outside.