Recoilless Weapon Gas Flow Control via Projectile-Blocked Openings

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Solution Overview

Problem

Existing high- and low pressure systems in recoilless weapons face challenges in achieving a balanced expelling of the counter-mass, leading to issues with recoil force, air pressure, and firing range due to rapid or slow gas pressure increases, and the weapons tend to be long and ungainly.

Innovation Solution

A recoilless weapon design with a launch tube, a projectile having an inclined rear part, and a counter-mass with a high pressure propellant chamber inside and a low pressure counter-mass chamber outside the tube, featuring gas openings configured in concentric circles that are successively unblocked by the projectile as it moves, allowing controlled gas flow regulation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If the gas passage is large, then the gas pressure increases fast and the counter-mass is expelled quickly, but this causes too fast expelling of the counter-mass which adversely affects recoil and pressure

Engineering Contradiction:
Improveexpelling speed of counter-massVSAvoidrecoil force
Core Design Contradiction:
SpeedVSForce

Solution Approach 1:

The gas passage is segmented into multiple gas openings arranged in at least two concentric circles around the launch tube. This segmentation divides the single large passage into multiple smaller passages, allowing controlled gas flow that prevents too-fast expelling of the counter-mass while maintaining effective propulsion.

Inventive Principle:
Principle #1Segmentation

2Force

If the gas passage is restricted by reducing the cross flow area, then the gas pressure increases slower and the counter-mass is expelled later, but this causes too slow expelling of the counter-mass which adversely affects firing range

Engineering Contradiction:
Improverecoil forceVSAvoidfiring range
Core Design Contradiction:
ForceVSLength of moving object

Solution Approach 1:

The gas openings are arranged in at least two concentric circles around the launch tube, utilizing the radial dimension. This multi-dimensional arrangement increases the total gas flow area compared to a single circular passage, allowing sufficient gas flow for adequate firing range while maintaining controlled pressure increase through the distributed opening configuration.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Force

If the high- and low pressure system is arranged in the launch tube, then the recoil and air pressure are reduced, but the launch tube becomes long and ungainly

Engineering Contradiction:
Improverecoil forceVSAvoidlaunch tube length
Core Design Contradiction:
ForceVSLength of moving object

Solution Approach 1:

The low pressure part (counter-mass chamber) is arranged outside the launch tube in a coaxial counter-mass tube, while the high pressure part (propellant chamber) remains inside the launch tube. This nested arrangement allows the pressure system to function effectively while keeping the launch tube compact and avoiding excessive length.

Inventive Principle:
Principle #7Nested doll (Nesting)

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

This design achieves a balanced recoil force and air pressure, a compact weapon form, and self-regulation of gas flow and temperature effects, enhancing firing range and reducing recoil forces.

Implementation Method 1

a propellant charge for propelling the projectile and the counter-mass out of the weapon

Methodology Applied
Scientific EffectCombustion: Combustion

Implementation Method 2

gas openings between the high pressure part and the low pressure part

Methodology Applied
Scientific EffectPressure gradient flow: Pressure Gradient

Data Source

PatentEP2396618B1Recoilless weapon
Publication Date: 2016.06.29 SAAB AB
  • EP2396618B1 patent drawingFigure 1
  • EP2396618B1 patent drawingFigure 2~3
  • EP2396618B1 patent drawingFigure 4~5

AI summary

The present invention relates in general to a recoilless weapon (1) and, in particular to a new high-and low pressure system for recoilless weapons (1). The invention provides a recoilless weapon (1) comprising a launch tube (2) open at muzzle (3) and breech (4) ends thereof, a projectile (5) and a counter mass (6) residing in said recoilless weapon (1), the recoilless weapon (1) further comprises a high pressure part (7) containing a propellant charge (8) for propelling the projectile (5) and the counter mass (6) out of the launch system (1), a low pressure part (9) containing the counter mass (6), a blocking element (16) in the rear part of the launch tube (2) and gas- openings (10) between the high pressure part (7) and the low pressure part (9) The invention is characterized in that the projectile (5) is positioned in a first start position, where the projectile (5) is blocking the gas-openings (10) and where the projectile (5), upon ignition of the propellant charge (8), moves to further positions (12') in the launch tube (2), where the gas-openings, successively, are unblocked by the projectile (5).