Method and arrangement for low or non-rotating artillery shells

• US 7,226,016 B2
• Filed: 03/28/2005
• Issued: 06/05/2007
• Est. Priority Date: 07/03/2000
• Status: Expired due to Term

• Current Assignee: BAE Systems Hã¤Gglunds AB
• Original Assignee: BAE Systems Hã¤Gglunds AB
• Inventors: Hellman, Ulf, Holmqvist, Ulf, Johnsson, Stig
• Primary Examiner(s): DINH, TIEN QUANG
• Application Number:
  US10/907,301
• Publication Number:
  US 20070084961A1
• Time in Patent Office: 799 Days
• Field of Search: 244/3.24, 244/3.26, 244/3.27, 244/3.28, 244/3.25, 244/3.23, 244/3.29, 102/473, 102/501
• US Class Current: 244/3.28
• CPC Class Codes: F42B 10/16 Wrap-around fins
• CPC Class Codes: F42B 10/18 using a longitudinally slidable support member
• CPC Class Codes: F42B 10/20 deployed by combustion gas pressure, or by pneumatic or hydraulic forces
• CPC Class Codes: F42B 10/40 with combustion of a slow-burning charge, e.g. fumers, base-bleed projectiles

Abstract

This disclosure relates to a method and an arrangement for low or non-rotating artillery shells fired from launch weaponry, and which introduces a portion of the barrel pressure built up in the barrel during the launch phase into a chamber arranged in the low or non-rotating artillery shell which is delimited in at least one direction by an element which is movable relative to the rest of the shell when a differential pressure between the chamber and the external environment of the shell is sufficient to move the element. The moveable element may be a protective casing covering fins of the artillery shell.

Claims

1. A method of launching a low or non-rotating fin-stabilized artillery shell from a launch weapon, the method comprising:

generating propellant powder gases in a barrel of the launch weapon during a launch phase of the low or non-rotating fin-stabilized artillery shell;

introducing at least a portion of the propellant powder gases from the barrel into a chamber of the artillery shell during the launch phase, wherein the chamber is arranged at a rear end of the shell to be in communication with a casing which is movable relative to a front portion of the low or non-rotating fin-stabilized artillery shell and which covers at least part of the rear part of the shell situated behind a drive band of the non-rotating fin-stabilized artillery shell;

applying a barrel pressure to an external rear portion of the casing so as to maintain a relative position of the casing with respect to the front portion of the low or non-rotating fin-stabilized artillery shell when the low or non-rotating fin-stabilized artillery shell is located inside the barrel during the launch phase;

after the low or non-rotating fin-stabilized artillery shell is located outside the barrel of the launch weapon after the launch phase, establishing a differential pressure with respect to an external atmosphere via an outlet in the casing to establish a differential pressure;

after the non-rotating fin-stabilized artillery shell has been launched from the launch weapon, removing the casing from the shell by using the differential pressure;

deploying fins of the low or non-rotating fin-stabilized artillery shell in response to the removal of the casing; and

enabling free rotation of the fins with respect to the front portion of the low or non-rotating fin-stabilized artillery shell about a longitudinal axis of the artillery shell by using a ball bearing assembly arranged around the longitudinal axis.

2. The method of claim 1, wherein the at least a portion of the propellant powder gases are introduced at high pressure in said chamber via an inlet dimensioned in such a way that, when a counter-pressure drops to a normal atmospheric pressure outside the barrel, the propellant powder gases introduced at high pressure into said chamber are not equalized at the same rate, but instead provide a relative displacement of the casing in a rearward direction with respect to the front portion of the non-rotating fin-stabilized artillery shell.

3. The method of claim 1, wherein a pressure from the propellant powder gases is accumulated in the chamber via an inlet which is dimensioned in such a way that, when a counter-pressure external to the chamber drops to a normal atmospheric pressure outside the barrel, the propellant powder gases in the chamber are at a higher pressure than the normal atmospheric pressure, wherein the higher pressure give rise to the displacement of the casing in a rearward direction with respect to the front portion of the non-rotating fin-stabilized artillery shell.

4. The method of claim 1, wherein said deploying fins of the non-rotating fin-stabilized artillery shell comprises, after the casing is removed, deploying a plurality of fins which are arranged in a rear part of the non-rotating fin-stabilized shell and which, from a retracted position, are forced out transverse to a direction of flight of the non-rotating fin-stabilized shell, wherein, during the launch phase, the plurality of fins are kept retracted by the casing covering the rear part of the non-rotating fin-stabilized shell,

wherein the casing is removed by the portion of the propellant powder gases accumulated in the chamber and, after the casing has been removed, a remaining gas pressure from the chamber is used to force out the fins.

5. The method of claim 1, further comprising, after the non-rotating fin-stabilized shell has been launched from the launch weapon, pushing a fin unit, initially located inside the non-rotating fin-stabilized shell, rearwards relative to a direction of flight of the non-rotating fin-stabilized shell behind a rear plane of the non-rotating fin-stabilized shell,

wherein the fin unit is pushed rearward by the portion of the propellant powder gases accumulated in the chamber.

6. A low or non-rotating fin-stabilized artillery shell which is suitable for use in conjunction with the method of launching a non-rotating fin-stabilized artillery shell of claim 1, the non-rotating fin-stabilized shell comprising:

a chamber arranged inside the non-rotating fin-stabilized shell and which is delimited in at least one direction by the casing which, in an original position during a launch phase of the non-rotating fin-stabilized shell from a barrel, is externally acted upon by a propellant powder pressure in the barrel;

an inlet which leads to said chamber from a part of the non-rotating fin-stabilized shell which, when viewed in a direction of flight, is situated behind a skidding drive band, wherein some of the barrel pressure during the launch phase gains access to the chamber through the inlet; and

a plurality of fins arranged in a rear portion of the non-rotating fin-stabilized artillery shell;

wherein the ball bearing assembly enables free rotation of the plurality of fins with respect to a front portion of the non-rotating fin-stabilized artillery shell about a longitudinal axis of the non-rotating fin-stabilized artillery shell.

7. The low or non-rotating fin-stabilized artillery shell arrangement of claim 6, wherein the inlet is dimensioned such that the pressure which builds up inside the chamber during the launch phase of the shell acts upon the casing after the non-rotating fin-stabilized shell has been launched from the launch weapon.

8. The low or non-rotating fin-stabilized artillery shell arrangement of claim 6, wherein the plurality of fins are initially arranged in a rear part of the non-rotating fin-stabilized shell first in a retracted position, and then in a position which is transverse to a direction of flight of the non-rotating fin-stabilized shell after the non-rotating fin-stabilized artillery shell exits the barrel, wherein, during the launch phase, the plurality of fins are kept retracted by the casing.

9. The low or non-rotating fin-stabilized artillery shell arrangement of claim 6, wherein the plurality of fins are arranged in a fin unit which is initially located inside the non-rotating fin-stabilized shell, and which is moved rearwards relative to a direction of flight of the non-rotating fin-stabilized shell behind a rear plane of the non-rotating fin-stabilized shell after the non-rotating fin-stabilized artillery shell exits the barrel.

10. The method of claim 1, wherein said deploying fins comprises pivoting the fins around respective axes arranged along a longitudinal axis of the artillery shell.

11. A low or non-rotating fin-stabilized artillery shell, the fin-stabilized shell comprising:

a chamber arranged inside the non-rotating fin-stabilized shell;

a casing arranged in an original position during a pre-launch phase so as to cover a plurality of folding fins, wherein an exterior portion of the casing is further adapted so as to be externally acted upon by a barrel pressure during a launch phase;

an inlet allowing communication between said chamber and said exterior portion of the casing and through which the chamber is pressurized by a barrel pressure during the launch phase,

wherein, after the artillery shell has exited the barrel, and in response to a differential pressure between the chamber and the exterior portion of the casing, the casing is removed so as to enable unfolding of the plurality of folding fins; and

a ball bearing assembly arranged to enable free rotation of the plurality of folding fins about a longitudinal axis of the artillery shell with respect to a front portion of the artillery shell.