Apparatus comprising a ring-shaped nozzle, for manufacturing a hollow body comprised of plastic material

An apparatus for manufacturing a hollow body of thermoplastic material, said body has a formed head piece and a body member formed by blow-molding a tube segment attached to and integral with the head piece, comprising:

• a ring-shaped nozzle with a ring shaped nozzle opening bounded by a nozzle piece and a controllably, reciprocally movable nozzle cone piece;
• a withdrawal device operaive with respect to said ring-shaped nozzle, said withdrawal device is axially, reciprocally movable and has a recess for said head piece;
• a blow mold with a plurality of blow mold parts which are laterally reciprocally movable, wherein, when the blow mold is closed, its support surface on bottom members rests on a seat surface on said nozzle piece, and said closed blow mold leaves said nozzle opening free;
• and
• a blowing device which blows the extended withdrawn tube segment against the closed blow mold;
• whereby,
• the said closed blow mold leaves free said passage to said nozzle opening;
• a control device is provided for controlling the stretching of said extruded tube segment by means of said withdrawal device, under conditions of cessation of a feed of plastic;
• said nozzle opening is open until a start of said blowing process;
• and
• at said start of said blowing process, said nozzle opening is controlled such that said opening is closed by shear action, while said hollow body is under pressure, wherein as part of the shear action, a forward end member of the cone piece entirely passes between said bottom members of the closed blow mold.