Underwater Firearm Muzzle Valve Gas Bubble Mechanism

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Solution Overview

Problem

Current devices for underwater firearm firing from a dry environment face challenges such as barrel rupture due to water penetration, reduced projectile velocity, and hydraulic shock waves, limiting the effectiveness and reliability of firearms, especially at high firing rates.

Innovation Solution

A device with a controllable muzzle valve and pyrotechnic charge that generates excessive pressure within a housing, bypassing gas into the water to form a gas bubble, reducing propellant gas pressure and hydraulic shock, and ensuring the muzzle valve is open only during firing, using a mechanical or electromechanical drive for reliable operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the barrel is completely filled with water before firing, then the projectile can enter the water effectively, but the barrel may swell and rupture due to water pressure

Engineering Contradiction:
Improvebarrel integrityVSAvoidwater pressure on barrel
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies preliminary action by pre-filling the barrel with water before firing. This ensures that when the projectile exits, it immediately enters water rather than air, enabling effective underwater engagement. The barrel is prepared in advance with the necessary medium (water) to eliminate the harmful air gap that would otherwise cause projectile deceleration and cavitation issues.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent employs flexible sealing elements including an O-ring and a flexible membrane at the muzzle end. These flexible components can deform under water pressure to seal the barrel effectively, preventing water from entering the weapon mechanism while allowing the barrel to be completely filled with water. The flexible membrane specifically prevents water ingress into the barrel during the filling process while maintaining structural integrity under pressure.

Inventive Principle:
Principle #30Flexible shells and thin films

2Speed

If the propellant gas pressure is increased to increase muzzle velocity, then the projectile velocity increases, but the hydraulic shock wave and damage to the barrel increase

Engineering Contradiction:
Improvemuzzle velocityVSAvoidhydraulic shock wave
Core Design Contradiction:
SpeedVSObject-generated harmful factors

Solution Approach 1:

The patent introduces a gas bubble as an intermediary between the propellant gas and the water. The propellant gas first fills this bubble, which then collapses as the projectile exits. This intermediary absorbs and distributes the energy transfer, reducing the direct hydraulic shock wave generated when high-pressure gas contacts water. The gas bubble acts as a buffer that mediates the interaction between the high-pressure propellant system and the external water environment.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the physical parameters of the propellant gas by allowing it to expand into a larger volume (the gas bubble) before the projectile exits. This expansion reduces the peak pressure of the gas, thereby reducing the hydraulic shock wave when the gas contacts water. By controlling the timing and volume of gas release, the system optimizes muzzle velocity while minimizing harmful hydraulic effects.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If the firing rate is increased to 600 rounds/min, then the productivity increases, but the barrel cannot be completely filled with water between shots

Engineering Contradiction:
Improvefiring rateVSAvoidbarrel water filling
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent ensures continuous water presence in the barrel by using the projectile and cartridge case as pumping elements. As these components move through the barrel during each firing cycle, they actively push water forward, maintaining continuous water filling even at high firing rates of 600 rounds per minute. This eliminates idle time where air might enter the barrel, ensuring the barrel remains completely filled with water between shots.

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The system uses the existing firing mechanism components (projectile, cartridge case) to perform the additional function of water pumping. These components, already moving through the system as part of normal operation, automatically displace water and maintain the water-filled state of the barrel without requiring separate pumping mechanisms. The system serves itself by utilizing its own operational elements to maintain the necessary water environment.

Inventive Principle:
Principle #25Self-service

4Object-generated harmful factors

If a muzzle device with membranes is used to reduce propellant gas pressure, then the hydraulic shock wave decreases, but the device complexity increases

Engineering Contradiction:
Improvehydraulic shock waveVSAvoidmuzzle device structure
Core Design Contradiction:
Object-generated harmful factorsVSDevice complexity

Solution Approach 1:

The patent makes the flexible membrane serve multiple functions: it seals the muzzle end to prevent water ingress, it allows controlled gas passage to reduce pressure, and it maintains barrel integrity under water pressure. By making one component perform multiple roles, the design avoids adding separate devices for each function, thereby reducing overall system complexity while still achieving hydraulic shock wave reduction.

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

Solution Approach 2:

The patent uses a flexible membrane made of elastomeric material that can deform under pressure differentials. This flexible film naturally responds to pressure changes, allowing gas to pass through when internal pressure exceeds external water pressure, while maintaining a seal when pressures are equalized. The flexibility of the membrane provides passive pressure regulation without requiring complex mechanical control mechanisms.

Inventive Principle:
Principle #30Flexible shells and thin films

Data Source

PatentEP2690390B1Device for underwater firing from a firearm
Publication Date: 2016.08.10 DSG TECH LTD
  • EP2690390B1 patent drawingFigure 1
  • EP2690390B1 patent drawingFigure 2

AI summary

The invention relates to a firearm, to be more precise to devices providing the possibility of underwater firing from a dry firearm. The device for underwater firing from a firearm comprises a firearm with ammunition, a firing control means, and a controllable muzzle valve, a through-opening in said muzzle valve being intended for the flight of an underwater charge on discharge. Furthermore, the device comprises an outer housing, within which at least a firearm and ammunition are arranged. The firing control means is equipped with at least one pyrotechnic charge intended for producing, prior to firing, an excess gas pressure in the housing which exceeds the external water pressure. Furthermore, the firing control means is connected to the muzzle valve so as to provide the possibility of firing after the muzzle valve has opened as a result of an increase in the pressure of the pyrotechnic gas inside the housing and a cessation of the firing once the muzzle valve is closed. Furthermore, the muzzle valve is mounted so as to provide the possibility of the pyrotechnic gas passing through the through-opening therein out of the housing into the water. The invention increases the firing efficiency underwater and the reliability of the device for underwater firing from a firearm