Patent GB-1014866-A (GB)
Title: Improvements relating to projectiles and the manufacture thereof
Inventor: LOBELLE MARCEL JULES ODILON
IPC: F42B10/14
Filed: 1962-11-19
Abstract: 1,014,866. Making propulsion nozzles for projectiles; jointing by forging. M. L. AVIATION CO. Ltd. Nov. 11, 1963 [Nov. 19, 1962], No. 43676/62. Headings B3A and B3H. [Also in Divisions F1 and F3] The invention relates to a propulsion nozzle assembly of a rocket-driven projectile of the kind which is fired from a launcher tube, the projectile having fins pivotally mounted at the rear thereof for stabilizing the projectile in flight. The nozzle assembly is shown in Fig. 2 and comprises a first portion A which is made of steel and defines a cylindrical portion 15, convergent portion 16, a throat portion 17 and a first part 18 of the divergent portion of the nozzle. The upstream end of the nozzle portion A is screwthreadedly engaged at 2 with the body portion 1 of the projectile. The nozzle assembly comprises also a second portion B made of a material lighter than steel, for example aluminium alloy, the portion B defining the final part 24 of the divergent portion of the nozzle. The outer surface of the steel portion A terminates in a reduced diameter portion 9, an inwardly tapering portion 11 and a portion 13 of the same diameter as the portion 9, shoulders 10 and 12 being formed between the surfaces 8 and 9 and 11 and 13, respectively. The inner surface 20 of the aluminium portion B is of the same diameter as the portions 9 and 13 of the steel portion A, the inner surface being continued by a divergent surface 21, a shoulder 22 and stepped portion 23 and finally a divergent portion 24, the latter portion in the assembly forming a continuation of the divergent portion 18 of the steel nozzle portion A. The nozzle portions are assembled together, the surface 20 of the portion B sliding over the surfaces 13 and 9 of the portion A until the forward end 25 of the portion B abuts against the shoulder 10 of the portion A. A swaging tool is then entered into the nozzle assembly and the down-stream end portion 13, 18 of the nozzle portion A is expanded to the position shown in Fig. 2 in which the shoulders 12 and 22 and the surfaces 13 and 23 engage. A further swaging operation is performed along the line 25 where the divergent surfaces 18 and 24 adjoin so as to ensure a continuous surface. Radial holes 3 are formed in the nozzle portion B and stabilizing fins 5 are pivotally secured thereto by means of screws 4. The fins 5 are protected by means of a casing 6 and are held in the retracted position shown in Fig. 2 by the launcher discharge tube. Upon leaving the discharge tube the fins are moved to their operative positions by means of a spring 7. An apparatus in which the assembly is made is described, the apparatus comprising a plate which is mounted for vertical movement on four vertical pillars upstanding from a base-plate. Springs are disposed between the movable plate and the base-plate. The nozzle portions A and B are located in a guide block which is itself located on the movable plate by means of four guide ports. The nozzle parts are forced together by means of hydraulic pressure.