Extendible thrust nozzle for rockets

Abstract

A convergent-divergent rocket nozzle is made to be extendible by moving successively larger, conic annuli into a tandem arrangement therewith, so that they collectively form a single exit cone. In a stowed position, the movable, conic annuli concentrically surround the primary nozzle. Each of these movable segments of the nozzle is moved relative to its adjacent upstream segment by being attached to rotary means that engage elongated positive traction surfaces on a set of guide members that are spaced circumferentially about and fixed at each end to the upstream segment, parallel to the axis of the nozzle. The rotary means are actuated, by means of a flexible shaft, by a small, electric motor that is mounted to each movable segment. When in fully deployed position, each movable segment is locked in place by tang latches, fixed to the adjcent, upstream segment, that engage an internal flange or shoulder on the movable segment. Prior to deployment, the rotary means is disengaged from the positive traction surface of each guide member, and the tang latches, being outwardly spring biased, then function as deceleration means to slow the segment being deployed. An elastomeric ring is confined between flanges of each adjacent pair of nozzle segments, where it functions as a hot gas seal and as a shock absorber.