| 摘要 |
<p>1389950 Projectiles CANADA DEFENCE MINISTER OF 16 June 1972 [17 June 1971] 28421/72 Heading F3A A tubular projectile 10 which may be aerodynamically stabilized, spin stabilized, or stabilized by a combination of aerodynamic and spin forces, has its leading end 12 bevelled so as to releasably retain a front rider band 18 while its trailing end 14 is formed with a radially extending rib 20 rearwardly of which there is provided a seat 22. The seat 22 is fluted and has a diameter less than the outer diameter of the projectile 10. A pusher base 26 is releasably mounted on the trailing end 14, being formed with a seat 32 adapted to closely receive the trailing end 14. A driving band 34 is removably mounted partly on the circumference of the pusher base 26 and partly on the seat 22 of the projectile 10, and serves to hold the pusher base 26 in place during handling of the projectile. A rubber seal 36 secured to the outer face 30 of the pusher base 26 prevents gases from flowing past the projectile during launch. In a spin stabilized mode, the outer surface of the projectile is extended by the launcher riflings to produce the desired spin rate. Upon exit from the muzzle of the launch tube, the bands 18, 34 are separated and discarded by the large centifugal forces which have been built up. The pusher base 26 is subsequently pushed out of the back of the projectile, this being caused by the large stagnation pressure created by the normal shock wave ahead of the projectile. Once the projectile is in free flight, the flow of air is supersonic both internally and externally. In an aerodynamically stabilized mode, the bands 18, 34 are separated and discarded after launching by the combined effects of air friction drag and stagnation pressure generated by movement of the projectile in free flight.</p> |
