METHOD AND EQUIPMENT FOR PRODUCTION OF CROSS-RIBBED INSIDE TUBE FOR SPECIAL TWO-WALL GASEOUS DISCHARGE TUBE WITH HIGH ANGULAR SELECTIVITY

摘要

A method and apparatus for the production of a transversely corrugated or serrated interior pipe of a double walled special gas discharge pipe with high angle selectivity, especially to the production of such pipe from silicate materials, preferably for CO2 laser with axial gas discharge with high amplification, the method and apparatus providing for the economic production of such pipes from silicate materials, with defined sharp-edged corrugations, in the required accuracy and quality. This is accomplished by forming an interior pipe from a smooth cylindrical glass pipe, which has been heated by means of suitable heat sources, until the material can be plastically formed. For this, an inner transformation tool, into the outer jacket of which the corrugated form required for the interior pipe has worked in, is used, as well as an outer transformation tool, the outer jacket of which has at least two corrugations with a design which is complementary to the inner transformation tool, with the inner transformation tool being fixed, while the pipe to be transformed is displaced in a slow rotary movement, and with the outer transformation tool being pressed against the outer jacket following the heating of the pipe segment to be transformed, so that the required corrugation is formed. The transformation process proceeds so that always at least one corrugation of the outer transformation tool is guided in the corrugation formed during the respective preceding working step, when forming the respective next corrugation. In an alternative embodiment, the inner transformation tool is vertically displaceable and the pipe is stationary, the tool being mounted to a longitudinally extending shaft, so that the tool cooperates with the outer transformation tool by vertically upwards displacement of the inner tool.