Pressure Cooker Bolt Lock for Safe Retractable Lid Opening

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Solution Overview

Problem

Existing pressure cooking appliances with retractable lids face issues such as improper handling leading to safety risks, high costs due to over-engineering of safety features, difficulty in industrialization, and lack of clear locking indications, which compromise user safety and reliability.

Innovation Solution

A pressure cooking appliance with a retractable cover featuring a self-activating lock that prevents the control mechanism from opening, allowing safe handling and use, regardless of pressure levels, and a design that optimizes the safety finger's durability without increasing costs, while providing visual and auditory feedback for proper locking.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a flexible lid pressure cooker with a long lever is used to exert sufficient tensile force on the cover, then the cover can be properly deformed and sealed, but the lever becomes prone to being grasped and lifted by users, creating safety risks

Engineering Contradiction:
Improvetensile force on coverVSAvoidsafety risk from improper handling
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

A bolt is introduced as an intermediary component between the lever and the cover. The bolt transmits the tensile force from the lever to the cover while preventing direct grasping of the lever. The bolt acts as a mechanical mediator that separates the force transmission function from the handle function, eliminating the safety hazard while maintaining the required sealing force.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The force transmission system is segmented into distinct components: the lever for user operation, the bolt for force transmission, and the cover for sealing. This segmentation allows each component to perform its specific function optimally - the lever can be shorter and safer, while the bolt provides the necessary mechanical advantage to deform the flexible cover without requiring user grasping of the lever itself.

Inventive Principle:
Principle #1Segmentation

2Object-affected harmful factors

If safety features are over-engineered to prevent accidental opening, then user safety is improved, but manufacturing costs increase

Engineering Contradiction:
Improveuser safetyVSAvoidmanufacturing cost
Core Design Contradiction:
Object-affected harmful factorsVSEase of manufacture

Solution Approach 1:

The bolt system is designed to be self-activating through the natural movement of the lever. When the lever is moved to the closed position, the bolt automatically engages with the cover to lock it in place. This self-service mechanism eliminates the need for complex electronic sensors, motors, or expensive safety systems, providing reliable safety at low manufacturing cost.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The invention replaces complex electronic or multi-component mechanical safety systems with a simple bolt-lever mechanical system. The safety function is achieved through basic mechanical principles - the bolt physically blocks the lever from moving to the open position unless properly activated, providing foolproof safety without expensive electronics or complex mechanisms.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Ease of operation

If the control means is made movable to allow opening and closing operations, then ease of operation is improved, but reliability decreases due to potential accidental activation

Engineering Contradiction:
Improveease of opening and closingVSAvoidrisk of accidental opening
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The bolt is positioned and configured in advance to engage with specific features on the cover and lever. Before the lever can move to the open position, the bolt must be in its locked engagement state. This preliminary positioning ensures that accidental movements cannot activate opening, as the pre-configured bolt physically prevents lever movement unless deliberately actuated through the proper sequence.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The bolt provides a preliminary counter-action to any attempted lever movement. The mechanical interference fit and engagement features of the bolt create a preliminary barrier that prevents accidental activation. The bolt's design includes features that actively resist unintended lever movement, requiring deliberate user action to overcome the preliminary anti-action and initiate opening.

Inventive Principle:
Principle #9Preliminary anti-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 solution enhances user safety and ergonomics, reduces manufacturing complexities, and ensures the appliance cannot be opened unless properly supported, thereby preventing accidents and improving reliability.

Implementation Method 1

designed to prevent relative movement between the cover and the tank

Methodology Applied
Scientific EffectMechanical constraint: Mechanical Fastener

Implementation Method 2

The interior of the enclosure can thus reach high pressure and temperature when the device is subjected to the influence of a heat source

Methodology Applied
Scientific EffectPressure control: Pressure Increase

Implementation Method 3

when the device is subjected to the influence of a heat source

Methodology Applied
Scientific EffectThermal heating: Heating

Implementation Method 4

cook the food present in the chamber under steam pressure

Methodology Applied
Scientific EffectSteam pressure cooking: Pressure Increase

Data Source

PatentEP1938717B1Pressure-cooking device provided with a bolt
Publication Date: 2010.08.25 SEB SA
  • EP1938717B1 patent drawingFigure 1~2
  • EP1938717B1 patent drawingFigure 3~4
  • EP1938717B1 patent drawingFigure 5~6

AI summary

The appliance (1) has a controlling unit (5) controlling displacement of an engageable lid (3) between closed and open positions. The controlling unit is movably mounted between positions corresponding to respective closed and open positions of the lid. A deactivable/activable lock (15) avoids the controlling unit from reaching its one position, from the other position when the lock is activated. The lock is independently activated from a pressure level reigning inside a hermetically sealed cooking chamber.