To manufacture a circular corrugated metallic tube whose ratio of the wave depth Wt to the wave pitch Ws is more than 0.3.
The rotary axis which is rotatable around an axis orthogonal to the longitudinal axis of the tube and is positioned on the perpendicular plane orthogonal to the longitudinal axis is fed to a pressure roll while the corrugated shape is formed and rotated around a smooth pipe rotating the pressure rolls in sequence by the feeding motion. At least by one pressure roll, a circular corrugated metallic tube, especially a circular corrugated metallic tube of a coaxial high frequency cable external conductive body, is manufactured by the equipment, in which a) the tooth tip. is formed flat, b) the pipe is guided in a state that the pipe is closely attached to a guide bush (12) in the forewarder and the rearwarder zones than the section where the pipe meshes with the pressure roll (13), c) the number of teeth (Z) is 7-11, preferably 8-10, as the features.
JANK KLAUS-D
MEYER MICHAEL
STROHMEYER ROBERT
HARTEN FRIEDRICH
| US3780556A | 1973-12-25 |