Device for producing cross-finned pipes

Apparatus for the production of transversely ribbed tubes, comprising:

• mold jaw halves which bear against each other along a common mold section with front faces thereof and which form a mold passage therebetween, wherein said common mold section has a first surface thereof and a second surface thereof remote from and in opposite relationship to said first surface;
• wherein each mold jaw half is connected at said first surface to a support element, with said support element guided along a first linear guide device;
• wherein each mold element is connected at said second surface to a guide and slide element, which guide and slide element is guided along a second linear guide device which is parallel to the first linear guide device;
• with the support element and the guide and slide element comprising the same material, and with the mold jaw halves comprising a material of specific weight which is low in comparison with the material for said support element and for said guide and slide element, and with the mold jaw halves having a coefficient of expansion and thermal conductivity high in comparison with the coefficient of expansion and thermal conductivity of said support element and said guide and slide element;
• and
• wherein the longitudinal extent of each mold jaw half and the longitudinal extent of each support element and guide and slide element in the direction of said mold section, the coefficients of expansion of the material for the support elements and guide and slide elements, the coefficient of expansion of the mold jaw halves, the ambient temperature and an operating temperature are related as:
• A(T.sub.0).multidot.(1+.alpha..sub.A T)=B(T.sub.0).multidot.(1+.alpha..sub.B T)
• wherein A is the longitudinal extent of the support element and the guide and slide element, .alpha..sub.A is the coefficient of thermal expansion of the material for the support element and for the guide and slide element, B is the longitudinal extent of the mold jaw halves, .alpha..sub.B is the coefficient of thermal expansion of the material for mold jaw halves, T.sub.0 is the ambient temperature, and T is the operating temperature.