METHOD AND APPARATUS FOR MAKING HELICAL GROOVES IN SMALL-SIZE THIN-WALL PIPES Russian patent published in 1994 - IPC

FIELD: radioelectronics. SUBSTANCE: pipe workpiece is lowered onto a screw template whose length exceeds that of the workpiece by one screw pitch. Screw template has cylindrical and helical portions. End of the cylindrical portion of the screw template and end of the workpiece are aligned, and helical part of the screw template in inserted into a guide to be orientated so that sharp projections of rollers enter helical grooves of the projection part of the template and fed to rollers until end of the workpiece is engaged with the rollers. Pressure screw acts to move the template and workpiece forward to a length necessary for forming helical grooves on end of the workpiece. Rollers have a shape conforming to the cross section of the groove in a plane perpendicular to the helical groove. The rollers are positioned at an angle twice the angle of elevation of helical grooves. Guide axis of hole extending through vertical axis of rollers is inclined to the plane of each roller to the value of elevation angle of the helical line to separate the angle between the plane of rollers into two equal parts. Apparatus has means for adjusting clearances, angular position, and aligning of axes. EFFECT: capacity to roll multistart helical grooves, enhanced production accuracy, simplified manufacture. 3 cl, 4 dwg