Projectile and method for sealing a projectile in a barrel
View Patent ↗A weapon ( 104 ) including a stock, a barrel assembly ( 105 ) slidably mounted on said stock whereby, on discharging said weapon, the barrel assembly ( 105 ) slidably recoils relative to said stock, and a damper ( 107 ) for decelerating the recoiling barrel assembly, wherein said barrel assembly ( 105 ) includes a plurality of projectiles axially disposed within a barrel ( 108 ) wherein each of said projectiles is associated with a discrete propellant charge for propelling said projectile from the barrel. Suitably the weapon further includes a breech block ( 109 ) which slidably recoils relative to said stock and a further damper ( 106 ) for decelerating the recoiling breech block.
1. A barrel assembly having
a barrel including a plurality of projectiles aligned nose to tail,
each of the plurality of projectiles associated with a respective propellant charge for sequential firing from the barrel,
each of the plurality of projectiles having a spine and an expandable collar surrounding the spine and a complementary surface on the collar engaging a complementary surface on the respective spine,
each collar being expanded into engagement with the bore of the barrel by interaction of the complementary surfaces and each collar being expanded by rearward forcing of the spine with respect to the collar;
the distance to the centre axis of the projectile of a portion of one of the complementary surfaces reducing toward the rear of the barrel; and
each collar having a relaxed position on the spine for carrying the collar as the projectile leaves the barrel.
2. A barrel assembly as in claim 1 wherein the projectiles are spaced apart in the barrel by their respective propellant charges.
3. A barrel assembly according to claim 1 further having an ignition system for firing the projectiles sequentially from the barrel.
4. A method of firing projectiles from a barrel, including:
providing a plurality of projectiles, each of the plurality of projectiles associated with a respective propellant charge and includes a spine and a collar surrounding the spine,
aligning the plurality of projectiles axially within the barrel,
exerting a force down the barrel to force the spines rearwards within their respective collars,
expanding the collars as a result of the respective force of spines on the collars,
forming multiple engagements between the collars and the barrel as result of respective expansions, and
firing the projectiles sequentially from the barrel.
5. A method of firing projectiles according to claim 4 wherein the force down the barrel is exerted on the projectiles by reaction to firing of the propellant charges.
6. A method of firing projectiles according to claim 4 wherein the force down the barrel is exerted before the projectiles are fired.
7. A method of firing projectiles according to claim 4 wherein expansion of each collar is caused by relative movement between complementary surfaces on the collar and the respective spine.
8. A method of firing projectiles according to claim 4 wherein expansion is caused be interaction between conical complementary surfaces on the collar and the respective spine and wherein the conical complimentary surfaces taper towards the rear of the barrel.
9. A method of firing projectiles according to claim 4 wherein the propellant charges are provided between the projectiles and serve to space the projectiles within the barrel.
10. A method of firing projectiles according to claim 4 wherein the collars are initially set in grooves in the barrel bore prior to exerting the force down the barrel.
11. A method of firing projectiles according to 10 wherein the leading faces of the grooves are inclined to assist disengagement of the projectiles during firing.
12. A method of firing projectiles according to claim 4 wherein expansion of each collar is caused by interaction between complementary part-spherical surfaces on the collar and the respective spine.
13. A method of firing projectiles according to claim 4 wherein the engagements between the collars and barrel is a sealing engagement.
14. A barrel assembly as in claim 1 , expansion of each collar having been caused by relative movement between the complementary surfaces on the collar and the complementary surface on the respective spine.
15. A barrel assembly as in claim 1 wherein the complementary surfaces are substantially conical.
16. A barrel assembly as in claim 1 wherein the bore of the barrel includes grooves and the projectiles are spaced apart in the barrel by engaging the grooves.
17. A barrel assembly as in claim 16 wherein the grooves include leading faces located towards the muzzle of the barrel, the leading faces of the grooves inclined to assist disengagement of the projectiles during firing.
18. A barrel assembly as in claim 1 , wherein the complementary surfaces are part-spherical.
19. A barrel assembly as in claim 1 wherein the engagements between the collars and barrel is a sealing engagement.