Pressure-Actuated Mixing Chamber to Prevent Tire Sealant Backflow

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Solution Overview

Problem

Existing puncture repair kits suffer from backflow of puncture repair liquid when compressed air supply is stopped, leading to inefficiencies and potential spillage.

Innovation Solution

A mixing device with a movable upper member that opens and closes inlets based on air pressure, ensuring communication during air supply and isolation during air stoppage, preventing backflow and spillage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the compressor is stopped before the total amount of puncture repair liquid is supplied, then the injection process can be paused, but the remaining puncture repair liquid flows back to the compressor

Engineering Contradiction:
Improveability to pause injection processVSAvoidbackflow of puncture repair liquid
Core Design Contradiction:
Ease of operationVSObject-generated harmful factors

Solution Approach 1:

A check valve is introduced as an intermediary component between the mixing chamber and the compressor. This check valve allows compressed air to flow bidirectionally but prevents puncture repair liquid from flowing back to the compressor, thus solving the backflow problem while maintaining the ability to pause injection

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The mixing chamber design includes a movable upper member that dynamically opens and closes the communication between the second inlet and the mixing chamber based on air pressure. When air supply stops, the upper member closes to prevent backflow; when air supply resumes, it opens to allow liquid injection

Inventive Principle:
Principle #15Dynamics

2Object-generated harmful factors

If the upper member remains closed to prevent backflow, then puncture repair liquid is protected from spillage, but communication between inlets and outlet is blocked during air supply

Engineering Contradiction:
Improvespillage of puncture repair liquidVSAvoidcommunication efficiency during air supply
Core Design Contradiction:
Object-generated harmful factorsVSProductivity

Solution Approach 1:

The upper member is designed to be dynamically controllable, automatically opening when compressed air is supplied to allow liquid injection and closing when air supply stops to prevent backflow and spillage. This dynamic behavior resolves the contradiction between preventing spillage and maintaining communication efficiency

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system uses air pressure as feedback to control the state of the upper member. When air pressure is present, the upper member opens; when air pressure is absent, the upper member closes. This feedback mechanism ensures the system automatically adapts to operational conditions, maintaining productivity while preventing harmful backflow

Inventive Principle:
Principle #23Feedback

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

Effectively suppresses backflow and spillage of puncture repair liquid, enhancing operational efficiency and reducing material waste.

Implementation Method 1

the upper member moves in a direction away from the bottom surface due to supply of the compressed air

Methodology Applied
Scientific EffectCompressed air pressure: Pressure Increase

Implementation Method 2

moves toward the bottom surface due to stop of the supply of the compressed air

Methodology Applied
Scientific EffectPressure reduction: Pressure Drop

Data Source

PatentEP4520513B1Mixing device, mixing method, bottle unit, and puncture repair kit
Publication Date: 2026.03.18 SUMITOMO RUBBER INDUSTRIES LTD
  • EP4520513B1 patent drawingFigure 1
  • EP4520513B1 patent drawingFigure 2
  • EP4520513B1 patent drawingFigure 3

AI summary

The present invention is directed to a mixing device 4 including: a mixing chamber 6 which defines a space for mixing a puncture repair liquid R and compressed air A; a first inlet 7 for supplying the compressed air A to the mixing chamber 6; a second inlet 8 for supplying the puncture repair liquid R to the mixing chamber 6; and an outlet 9 for discharging a mixture of the puncture repair liquid R and the compressed air A from the mixing chamber 6. The mixing chamber 6 includes an upper member 10 which defines a top surface 6a of the space, and a lower member 11 which defines a bottom surface 6b of the space, in a state of use. The second inlet 8 is formed in the upper member 10. The upper member 10 moves in a direction away from the bottom surface 6b due to supply of the compressed air A to provide communication between the second inlet 8, and the first inlet 7 and the outlet 9 via the mixing chamber 6, and moves toward the bottom surface 6b due to stop of the supply of the compressed air A to close the communication between the second inlet 8, and the first inlet 7 and the outlet 9.