METHOD AND APPARATUS FOR MAKING TUBES WITH HELICAL CORRUGATIONS Russian patent published in 2000 - IPC

FIELD: plastic metal working, namely manufacture of corrugated tubes. SUBSTANCE: method comprises steps of forming corrugations on tubular blank by means of rollers; placing rollers around tube with inclination relative to its lengthwise axis; axially moving tube; changing height and pitch angle of helical line of corrugations at process of corrugating due to radially moving and rotating rollers around lengthwise axis of tube; in order to change height of corrugations and pitch angle of their helical line in cross section of tube and along its axis, radially moving rollers in opposite directions and with different speeds. Each roller is mounted in housing and is provided with mechanism for radially moving it and rotating it around lengthwise axis of tube. Said mechanism is in the form of kinematic pair with outer and inner links. Roller axle is mounted on inner link end which is nearest to axis of apparatus. Shape of working surface of roller corresponds to shape of recesses of corrugations. Outer link of first kinematic pair is inner link of second kinematic pair whose outer link is formed by housing of apparatus. One kinematic pair is reciprocation-type pair, other kinematic pair is rotary-type pair. Inner link of rotary kinematic pair includes connection unit for joining by means of common link with connection units of other mechanisms. EFFECT: enlarged manufacturing possibilities, enhanced efficiency. 13 cl, 4 dwg