Barrel and launching device as well as method for firing off a projectile

Patent metadata

Field	Value
Publication number	US-12305944-B2
Application number	US-202218574010-A
Country	US
Kind code	B2
Filing date	Jun 25, 2022
Priority date	Jul 1, 2021
Publication date	May 20, 2025
Grant date	May 20, 2025

Abstract

A barrel for a launching device for launching projectiles with a propellant charge is arranged with a cross-section in the form of a curve of constant width. A launching device and a method for firing a rotation-stabilized projectile from a barrel are also provided.

First claim

The invention claimed is:

1. A combination of a barrel for a launching device and a projectile to be launched therefrom with a propellant charge
the barrel being provided with a cross-section in a form of a curve of constant width, where the curve of constant width of the barrel is defined by an expression

r
⁡
(
φ
)

=

D
2

+

C
2

⁢

sin
⁡
(

n
⁢
φ

)

,

where D is a core diameter of the barrel, C is a rotation diameter of the barrel, φ is an angle and n is an odd integer greater than or equal to 3, and
the projectile being made with a cross-section in a form of a curve of constant width of the projectile, where the curve of constant width of the projectile is defined by the expression

r
⁡
(
φ
)

=

F
2

+

E
2

⁢

sin
⁡
(

n
⁢
φ

)

,

where E is a rotation diameter E for a geometry of the projectile, and F is a core diameter for the geometry of the projectile.

2. The combination according to claim 1 , wherein n is 3.

3. The combination according to claim 1 , wherein the barrel is formed with a pitch of between 20 to 30 where pitch is rotation expressed in caliber where L is a length of the barrel needed to achieve a full rotational turn, and Dcross-section is a caliber so that pitch=L/Dcross-section.

4. The combination according to claim 1 , wherein F<D and E<C.

5. Firing device comprising a combination according to claim 1 .

6. Method for firing a rotationally stabilized projectile from a barrel, comprising
providing the barrel with a cross-section in a form of a curve of constant width of the barrel by the cross-section being rotated with a pitch over an axial extent of the barrel, where the curve of constant width is defined by an expression

r
⁡
(
φ
)

=

D
2

+

C
2

⁢

sin
⁡
(

n
⁢
φ

)

,

where D is a core diameter of the barrel, C is a rotation diameter of the barrel, φ is an angle and n is an odd integer greater than or equal to 3,
providing the projectile made with a cross-section in a form of a curve of constant width of the projectile where the curve of constant width of the projectile is defined by the expression r(φ)=F/2+E/2 sin (nφ), where E is a rotation diameter E for a geometry of the projectile, and F is a core diameter for the geometry of the, and
firing the projectile from the barrel.

Assignees

• Bae Systems Bofors Ab

Inventors

• Thuvander Fredrik

Classifications

• F42B14/00

  Projectiles or missiles characterised by arrangements for guiding or sealing them inside barrels, or for lubricating or cleaning barrels · CPC title

• B21C37/155

  Making tubes with non-circular section (B21C37/151, B21C37/154 take precedence) · CPC title

• F41A21/18

  Grooves-Rifling · CPC title

• F41A21/00

  Barrels; Gun tubes; Muzzle attachments; Barrel mounting means (F41A25/00 takes precedence; barrel attachments for firing grenades or riot-control ammunition from smallarms F41C27/06) · CPC title

• F41A21/16 Primary

  Barrels or gun tubes characterised by the shape of the bore · CPC title