Rocket-assisted projectile or gun-boosted rocket with supported propellant grain

Claim 1

Rocket-assisted projectile the driving part of which is a rocket motor consisting of a grain with a central perforation and a tube-formed case, the mantle of which forms the outer wall of the rocket propellant chamber and with a rear end, which has a central nozzle and one supporting tube, which forms the inner wall for the rocket propellant chamber and has connections to the chamber througH one or several openings, characterized in that the rocket grain consists of a solid propellant having a high tensile strength and subject to axial compression from axial launching forces, and that the supporting tube in the central perforation of the grain has an outer dimension which in every cross section of the tube is less than the dimension of the central hole in the grain thereby defining an annular space between the tube and the grain, and substantially surrounding the tube so that the grain during the launch will thereby compress axially under the influence of axial force and expand radially against the tube without cracking, and when the axial force ceases the grain will resume its earlier shape and consequently reform said annular space between the grain and the supporting tube whereby radial burning of the grain is rendered possible.