GB1192284A - Rocket Motor - Google Patents

Abstract

1,192,284. Rocket motors and igniters. AEROJET-GENERAL CORP. 26 April, 1968, No. 20016/68. Heading F3A. A pulse rocket motor has solid propellant in the form of three grains 18, 20, 22 which are caused to burn in succession with a short time interval therebetween by intervening membrane-igniters 24, 26 substantially similar to each other. As shown in Fig. 2 membraneigniter 24 comprises a disc 28 of frangible elastomeric material which is a good thermal insulator such as silicone or Buna N rubber. A recess 30 in the side of the disc facing the second grain 20 contains electrically actuated primers 32 energized through leads 33 and connected to a petal design of string-like pyrotechnic material 34. The recess 30 is closed or filled by pyrotechnic material 36 which may take the form of a layer of heat paper or the form of a slurry of aluminium, boron, potassium nitrate, potassium chlorate, and a binder. Since the first grain 18 is internal burning the membrane-igniter 24 has an erosion barrier 38. In operation, the grain 18 is ignited and the membrane-igniter 24 and barrier 38 prevents the heat from igniting the second grain 20. After a desired time interval following expiration of the grain 18 the primers 32 are actuated to ignite the grain 20, the membrane-igniter 26 preventing ignition of the grain 22. When grain 20 has expired the grain 22 is ignited by energizing the ignition elements of the membrane-igniter 26.