Disengageable Lid Control for Pressure Cooker Opening Safety

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing pressure cooking appliances face issues with user safety due to the risk of excessive force being applied when attempting to open the lid, leading to potential breakage of parts or sudden release of steam, which complicates design and increases costs, despite safety measures like metallic materials and oversized components.

Innovation Solution

A pressure cooking appliance design featuring a disengageable locking/unlocking control member and pressure-sensitive safety means, allowing the control member to move without unlocking the lid when the safety means is active, using standard materials and reducing user effort through a mechanical force limiter mechanism.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the control member is blocked by the safety rod when pressure exceeds safety level, then user safety is improved, but the risk of part breakage due to excessive user force increases

Engineering Contradiction:
Improveuser safetyVSAvoidpart breakage risk
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent introduces a decoupling mechanism where the control member is no longer directly coupled to the locking/unlocking means. Instead, an intermediary system allows the control member to rotate freely when the safety rod is in its blocking position, preventing force transmission to the locking mechanism. This mediator approach resolves the contradiction by allowing user input without transmitting excessive force to vulnerable parts.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system transitions from a static blocked state to a dynamic state where the control member can rotate independently. When pressure exceeds safety levels, the control member is decoupled from the locking/unlocking means, allowing it to move dynamically without affecting the locked state. This dynamic behavior prevents force accumulation and potential breakage while maintaining safety.

Inventive Principle:
Principle #15Dynamics

2Strength

If the control member is made disengageable to allow free movement when safety rod is active, then part breakage risk is reduced, but the complexity of the transmission mechanism increases

Engineering Contradiction:
Improvepart breakage riskVSAvoidtransmission mechanism complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The transmission mechanism is segmented into independent functional components: the control member for user input, the safety rod for pressure monitoring, and the locking/unlocking means for secure closure. The decoupling mechanism separates these segments, allowing the control member to operate independently when needed. This segmentation reduces overall system complexity by allowing each component to be optimized separately.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system changes the operational parameters of the control member based on pressure conditions. When pressure is safe, the control member is coupled to the locking/unlocking means for normal operation. When pressure exceeds safety levels, the coupling parameter changes, allowing free rotation. This parameter-based control simplifies the mechanism by using automatic state transitions rather than complex control logic.

Inventive Principle:
Principle #35Parameter changes

3Ease of manufacture

If standard materials are used instead of metallic materials, then manufacturing cost is reduced, but the strength and durability of safety-critical parts may be compromised

Engineering Contradiction:
Improvemanufacturing costVSAvoidsafety-critical part durability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent applies the principle of using inexpensive materials for components that are designed to be replaced rather than permanently retained. The control member and associated transmission components can be made from standard plastics or other inexpensive materials, as they may need replacement over time. This approach significantly reduces manufacturing costs while maintaining safety through the overall system design.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The system incorporates safety margins and protective design features that compensate for the use of standard materials. The locking/unlocking means and sealing components are designed with sufficient strength margins to ensure safety even when made from standard rather than premium materials. This beforehand cushioning approach allows cost reduction while maintaining reliability.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

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 design enhances user safety, reduces the risk of part breakage, and allows for the use of standard, inexpensive materials while minimizing user effort, maintaining reliability and safety without increasing weight or cost.

Implementation Method 1

a spring (17) mounted between the cover and the safety rod (7A) and designed to exert a restoring force on the safety rod (7A) in order to return the latter to its initial position when the pressure decreases

Methodology Applied
Scientific EffectSpring: Spring

Implementation Method 2

an opening safety means, capable of occupying an active position in which it prevents the lid from unlocking... a manometric safety rod mounted to slide vertically on the cover between a low return position and a high position which it reaches under the effect of reaching the level pre-determined safety pressure

Methodology Applied
Scientific EffectPressure-sensitive: Pressure Increase

Data Source

PatentEP2624728B1Pressure cooking appliance including a disengageable control member
Publication Date: 2016.08.03 SEB SA
  • EP2624728B1 patent drawingFigure 1~2
  • EP2624728B1 patent drawingFigure 3~5
  • EP2624728B1 patent drawingFigure 6~7

AI summary

The invention relates to a cooking device comprising: a bowl and a lid; a member (6) for controlling the locking/unlocking of the lid, which member can move between a first position and a second position; and an opening safety means (7) which can occupy an active position in which it prevents the lid from being unlocked. The device is designed such that, when the opening safety means (7) is not in the active position, the movement of the control member (6) from the first position to the second position thereof results in the unlocking of the lid. The device is characterised in that the control member (6) can be disengaged, such that, when the opening safety means (7) is in the active position, the control member (6) can move from the first position to the second position thereof without unlocking the lid. The invention is suitable for pressure cooking devices.