Schumag Ag

Schumag Gmbh

Walter Wetzels

Erwin Bock

Kurt Crott

Rainer Hergemoeller

Erich Voell

A pipe profiling machine improves the utilization of the working length of a profiling stone in the inner profiling of heat exchanger pipes. The press-on width of the revolving roller bodies, such as spherical, cylindrical, or barrel-shaped roller bodies, is substantially narrower than the profile width of the profiling stone so that in this area the profiling stone is worn out rapidly while the other area remains unworn. The press-on roller bodies and/or the profiling stone are/is oscillated axially back and forth within the axial working length of the profiling stone so that the entire profile range of the profiling stone can be utilized and so that radially outwardly projecting stripes on the pipes are avoided even if spherical roller bodies are used.

Apparatus for the inner profiling of tubes or pipes

A tubular blank formed by casting or extrusion or the like and having a relatively thick wall is prepared for a following drawing operation, such as a tandem or cascade drawing, by widening one end of the tubular blank with a shackled mandrel. Then the widened or distended section is stretched by a cooperative, external stretching action between the shackled mandrel and a draw plate to form a stretched section. Then, the stretched section is passed through a draw plate that may be the same or a different draw plate than the first mentioned draw plate, and then drawing over the shackled mandrel to provide the required reduced wall thickness for the following tandem drawing.

Method for preparing a tubular blank having a thick wall for a following

The invention relates to a method for the better utilization of the working width of a profiling stone in the inner profiling of heat exchanger pipes. The press on width of the revolving roller bodies is substantially narrower than the profile width of the profiling stone so that in this area the profiling stone is worn out rapidly while the other area remains unworn since it is not utilized. In order to avoid this, the invention suggests that the press on rollers and the profiling stone is moved within the range of the working width of the profiling stone axially back and forth so that the entire profile range of the profiling stone can be utilized.

Method for the inner profiling of tubes or pipes

Device for centerless grinding of rotation-symmetrical surfaces on workpieces at a grinding station, including drive means for turning a workpiece about the axes of symmetry thereof during grinding, a support bar for supporting the workpiece during turning, a rotatable disc being perpendicular to and disposed on each side of the workpiece generating vibrations of operating frequencies at the grinding station during grinding, at least one of the discs being a grinding wheel operating under grinding pressure, mechanical bearing supports and feed means for the discs forming an oscillating system with the discs generating resonance frequencies, and rigid connecting means for forming a rigid linkage of forces between the bearing supports and for increasing the resonance frequencies of the oscillating system beyond the operating frequencies.

Device for centerless grinding of rotation-symmetrical surfaces on work

Method for straightening elongated drawn round stock, which includes simultaneously advancing the stock in the longitudinal direction, rotating the stock about the longitudinal axis thereof and deflecting the stock from a straight line exceeding the yield point thereof in a straightening arc, and subjecting the surface of the stock to friction forces acting in the longitudinal direction during the deflection.

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Aachen, Germany

Walter Wetzels