Carbon/carbon rocket motor exit cone reinforcement

Claim 1

In a carbon-carbon exit cone for a rocket motor, which cone comprises a densified, carbonized laminate fabricated from a plurality of plies of phenolic resin-impregnated woven carbon cloth; which cone has a cylindrical section, a conical section and a transition section between and integral with said cylindrical section and said conical section, said cylindrical section having inside threads for connecting said cone to the throat piece of said rocket motor, said conical section diverging outwardly from said transition section; said cone comprising a first layer of cured material surrounding said cylindrical section, said transition section and a portion of said conical section, said first layer being fabricated from a plurality of spiral windings of phenolic resin-impregnated carbon fiber cloth tape, said cone yet further comprising a second layer of cured material surrounding said first layer above said cylindrical section and said transition section, said second layer being fabricated from a plurality of spiral windings of phenolic resin-impregnated high silica cloth tape; the improvement which comprises a third layer of cured material surrounding said second layer above said cylindrical section, said third layer being fabricated from helically wound epoxy resin-impregnated carbon fiber.