Projectile Body Pressure Equalization Holes
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional ammunition rounds face challenges in achieving optimal muzzle velocity and material flexibility due to pressure imbalances between the outside and inside of the barrel, leading to increased drag and limited material options for projectile construction.
Innovation Solution
The design of an elongated projectile body with radially protruding seals and pressure equalization holes allows for equalization of gas pressure, reducing drag and enabling the use of lower-strength materials, such as lead, while maintaining propellant volume and stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional ammunition design is used without pressure equalization, then the projectile body requires high strength to resist radial expansion, but this increases device complexity and limits material options
Solution Approach 1:
The patent introduces pressure equalization holes as an intermediary mechanism between the propellant cavity and the exterior environment. These holes allow gas pressure to equalize between the inside and outside of the barrel, eliminating the pressure differential that causes radial expansion. This mediator approach enables the use of lower strength materials like lead while maintaining structural integrity during firing.
Solution Approach 2:
The invention changes the pressure parameter by introducing holes that allow internal cavity pressure to equalize with external pressure. This parameter change from pressurized to equalized state eliminates the need for high strength materials to resist pressure differential, thereby expanding material selection flexibility.
2Weight of moving object
If the projectile body is made with thinner walls to reduce weight, then kinetic energy increases, but the projectile becomes more susceptible to radial expansion under pressure
Solution Approach 1:
The pressure equalization holes act as intermediaries that eliminate the pressure differential causing radial expansion. This allows thinner-walled projectiles to maintain their shape during firing, as the equalized pressure removes the outward force that would otherwise cause thin walls to bulge or expand.
Solution Approach 2:
By changing the pressure parameter through equalization holes, the patent enables thin-walled construction. The pressure parameter transitions from a high differential state (which requires thick walls) to an equalized state (which allows thin walls), thereby reducing projectile weight while maintaining structural integrity.
3Strength
If high strength materials are used for the projectile body, then resistance to radial expansion improves, but manufacturing complexity and cost increase
Solution Approach 1:
The pressure equalization holes serve as a simple intermediary structure that can be easily manufactured into the projectile body. Instead of requiring complex high strength materials, the invention uses this simple geometric feature (holes) to achieve the same effect of preventing radial expansion, thereby simplifying manufacturing.
Solution Approach 2:
The invention changes the pressure parameter through simple hole formation, avoiding the need for complex high strength materials. This parameter change approach maintains resistance to radial expansion while significantly simplifying the manufacturing process and material selection.
4Speed
If pressure equalization holes are introduced, then drag is reduced and muzzle velocity increases, but the projectile structure becomes more complex
Solution Approach 1:
The patent applies segmentation by dividing the projectile structure into distinct functional zones: the propellant cavity, the pressure equalization holes, and the exterior surface. This segmentation allows each component to perform its specific function efficiently, with the holes providing pressure equalization without requiring complex overall structural changes.
Solution Approach 2:
The invention applies local quality by introducing pressure equalization holes only in specific locations where needed for pressure balance, rather than changing the entire projectile structure. This localized modification reduces drag and improves muzzle velocity while adding minimal structural complexity.
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 enhances muzzle velocity by minimizing radial expansion and allows for the use of thinner-walled projectiles made from materials like lead, increasing kinetic energy and stopping power without compromising stability or propellant volume.
Implementation Method 1
the primer is initiated usually mechanically by striking with a firing pin. This in turn causes deflagration of the propellant. Deflagration of the propellant results in the rapid generation of a large volume of gas.
Implementation Method 2
a plurality of seals extending about an outer surface of the body, each seal protruding radially from the body to form a substantial seal against an inner circumferential surface of the barrel
Implementation Method 3
one or more holes formed in the body enabling fluid communication between the cavity and the seal bound outer surface portion of the body... equalisation of pressure between a portion of a length of the outside of the round and the inside of a barrel
Data Source
Figure 1
Figure 2~3
Figure 4
AI summary
A projectile (14) for an ammunition round (10) for use with a small arms or light firearm comprises an elongated projectile body (16). The projectile body (16) has first and second axially opposed ends (18, 20) respectively and a cavity (20) extending there between. The cavity is able to hold a quantity of propellant (24). A plurality of seals (26) extend about an outer surface of the body (16). The seals (26) protrude radially from the body (16) and operate to form a substantial seal against an inner circumferential surface of a barrel (12) of the firearm. Two of the seals (26b and 26c) are mutually adjacent and spaced apart in a direction of a longitudinal axis of the body to form a seal bound outer surface portion (36) of the body (16). One or more holes (38) are formed in the body (16) enabling fluid communication between the cavity (22) and the seal bound outer surface portion (36) of the body (16). This enables pressure equalisation inside and outside of the cavity (22) about the seal bound outer surface portion (36) when the projectile (14) is travelling through the barrel (12).