Method and apparatus for the manufacture of pipes of thermoplastics with transverse profile features

A method for the manufacture of pipes of thermoplastics with transverse profile features, comprising mold segment halves (4, 5) which are circulated and, subsequent to an extrusion head (7), disposed in two lines opposite to each other, with the mold segment halves (4, 5) of a line not being interconnected, and which complement one another by twos along a straight molding path (2), forming a closed hollow mold;

• wherein each of the mold segment halves (4, 5) of a line is guided out of the molding path (2) at the downstream end (70) thereof and substantially at right angles to a direction of production (6) by means of a conveying device (29) and is re-circulated to the upstream end (67) of the molding path (2), where it is again inserted in the molding path (2) and attached to the respective mold segment half (4, 5) that leads in the direction of production (6);
• wherein downstream of the downstream end (70) of the molding path (2) and on both sides thereof, an additional first mold segment half (4a, 5a) is kept in a first parking position (77) for insertion in the molding path (2);
• wherein at least one additional mold segment half (4b, 5b, 4c, 5c) is kept in at least one additional parking position (78, 79) between the first parking positions (77) for the first mold segment halves (4a, 5a) and the downstream end (70) of the molding path (2), these additional mold segment halves (4b, 5b, 4c, 5c) also being insertable in the molding path (2)
• wherein at least one further additional mold segment half (4b, 5b, 4c, 5c) is moved out of a path of displacement (85) of the first mold segment halves (4a, 5a), when the first mold segment halves (4a, 5a) are moved from their first parking position (77) toward the molding path (2);
• and
• wherein at the least further additional mold segment half (4b, 5b, 4c, 5c) is moved out of the path of displacement (85) of the first mold segment halves (4a, 5a), when the first mold segment halves (4a, 5a) are moved from the molding path (2) into the first parking position (77).