Patent ID: 6129885
Filing Date: 2000-10-10
Classification: B29C,B29L

Abstract:
A process for producing elongate curved hollow bodies at least partially comprising thermoplastic material whereinfirstly a preform is extruded from an extrusion head of an extrusion system,the preform is engaged by a gripping means which is movable in space,the preform is moved by the gripping means into the region of a guide stencil extending above the length of the mold cavity of a mold portion of a divided blow molding mold for receiving the preform, the blow molding mold being so arranged that the mold cavity surface for carrying the preform includes at least one portion longitudinal extending along the same horizontal plane,the preform is introduced into the top of the guide stencil by a downward movement of the gripping means and by a movement thereof following the configuration of the guide stencil, the guide stencil having first and second wall portions disposed at a spacing from each other and the spacing thereof increasing in an upward direction, the spacing at the bottom of the guide stencil approximately corresponding to the maximum width of the mold cavity, the spacing at the top of the guide stencil greater than the spacing at the bottom of the guide stencil, whereby the preform is guided by the guide stencil from the top towards the mold cavity in a definitive orientation relative thereto, the preform passing into the mold cavity through a lower opening in the bottom of said guide stencil towards which said preform is guided by said wall portions, the preform having a larger diameter than the depth of the mold cavity,the blow molding mold is closed, andthe preform in the closed blow molding mold is pressed by an increased internal pressure in the preform against the wall of the mold cavity thereby to form the hollow body therefrom.