초록

The method of manufacturing a preform having a supporting core by effecting successive passes with a plasma torch while material is being supplied, and by effecting at least one glazing step with the plasma torch and without material being supplied includes:

대표청구항 ▼

[ We claim:] [1.] A method of manufacturing a preform in an installation for manufacturing or building up preforms having supporting cores, said installation including at least rotation means having a horizontal axis of rotation and two mounting points between which the supporting core of the prefor

[ We claim:] [1.] A method of manufacturing a preform in an installation for manufacturing or building up preforms having supporting cores, said installation including at least rotation means having a horizontal axis of rotation and two mounting points between which the supporting core of the preform to be manufactured or built up is mounted, plasma-torch and material-supply means disposed radially relative to said supporting core and mounted to move in axial translation relative to and parallel to the supporting core so as to make said preform around said supporting core, said preform being manufactured or built up by effecting successive passes with the plasma torch while material is being supplied, said method including, after the plasma torch passes with material being supplied have been effected, at least one glazing step in which at least one pass is effected automatically and without cooling the preform, which pass is effected with a plasma torch and without material being supplied so as to consolidate deposits comprising condensation soot;said method including sequential steps of:a) a first glazing step effected at slow speed from a first end of the preform to a second end thereof;b) pre-separation of the preform adjacent to the first end;c) a second glazing step effected from the first end, or at least from the place of pre-separation, to the second end of the preform; andd) complete separation of the preform at the place of pre-separation;wherein, during pre-separation, the diameter of a portion the preform is reduced to substantially that of the supporting core.