Method and apparatus for producing pipes having a transverse profile from thermoplastic material

A method of producing pipes (71) having a transverse profile from thermoplastic material by means of circulating mold segment halves (4, 5) which are arranged in two opposite rows downstream of an extrusion head (7) and combine in pairs to form a closed hollow mold along a linear molding path (2),

• wherein each of the unconnected mold segment halves (4, 5) of a row are guided out of the molding path (2) at a downstream end (68) in a direction substantially at right angles to a direction of production (6) by means of a conveying device (29) and are guided back to the upstream end (70) of the molding path (2) where they are re-fed into the molding path (2),
• wherein downstream of the downstream end (68) of the molding path (2) and on both sides thereof, a respective additional mold segment half (74, 75) is stored in a parking position (76, 77), the additional mold segment half (74, 75) being feedable into the molding path (2) by means of the conveying device (29), and
• wherein the additional mold segment halves (74, 75) are removed from the molding path (2) at the downstream end (68) by means of a auxiliary conveying device (29′), which is separate from the conveying device acting as main conveying device (29), before being moved to the parking positions (76, 77) while a pair of mold segment halves (4, 5), which is disposed directly upstream of the additional mold segment halves (74, 75) in the molding path (2) when seen in the direction of production (6), is returned to the upstream end (70) of the molding path (2) where it is fed into the molding path (2).