GB660789A - Propellant charge - Google Patents

Abstract

660,789. Rocket propellent charges. AEROJET ENGINEERING CORPORATION. Jan. 22, 1948. [May 28, 1945] No. 2036/48. Classes 9 (i) and 9 (ii). A rocket propellent charge comprises a solid stick of self-combustible propellent with an ignition-retarding coating covered by a fireproofed wrapper, the coating consisting of a slow-burning thermoplastic material. A charge 10 for a rocket motor is formed by mixing asphalt with potassium perchlorate or other perchlorate. The mixture is heated and cast in a cylindrical mould. Whensolidified, the charge is coated with asphalt, thermoplastic resin or other thermoplastic slow-burning substances. The coated charge is then covered with a tape 14 helically wound along its cylindrical surface. Strips of tape 13 are placed over one end of the charge and a reverse helical winding 16 is then applied. A metal plate 17 with projections 18 is placed over the covered end and secured to the charge by strips 20 extending along the charge. A third helical winding 30 is carried along the charge in the same sense as the first winding. A fireproofing solution such as ammonium sulphamate or zinc chloride is sprayed over the tape and when dry a corrugated paper liner 21 is secured to the charge by tapes. The exposed end 15 of the charge is grooved to facilitate ignition and the charge is inserted into the combustion chamber 23 of a jet motor 22 with the exposed end adjacent nozzle 24. A spacing disc 26 of ethyl cellulose, rubber or other thermoplastic material is placed against the covered end of the charge and an end cap 25 is then screwed on to the chamber. The charge is fired electrically by closing the circuit through leads 29 to an igniter 28.