Multi-stage rocket motors

Abstract

A motor for impelling a missile or projectile has a housing and a plurality of spaced walls defining progressive compartments in the housing. A nozzle in one of the compartments produces a thrust for the missile or projectile when pressurized gases flow through it. Igniters extending into the individual compartments ignite propellants in such compartments. The igniter in an individual one of the compartments is energized initially and the igniters progressively displaced from such individual compartment are thereafter energized sequentially. Each wall separating an individual pair of adjacent compartments has a normally closed valve. Each valve has a first orifice of relatively great area in the compartment closer to the nozzle and a second orifice of limited area in the compartment further from the nozzle. A membrane between the orifices prevents the valve from being opened by a pressure from the closer compartment until this pressure becomes relatively great (e.g. 6500 psi). When a comparatively low pressure (e.g. 1500 psi) is applied in the second orifice by propellant combusting in the further compartment, the membrane ruptures. The rupture is facilitated by dimpling the membrane in the direction from the second orifice toward the first orifice. When the membrane is ruptured, gases from the propellant combusting in the further compartment flow through the valve and then through the nozzle and gradually erode the membrane and orifice. This causes the gases in the compartments to be maintained at equal pressures sufficiently great to sustain the propellant combustion in the further compartment.