REDUCING THE DIAMETER OF TUBULAR BODIES

摘要

REDUCING THE DIAMETER OF TUBULAR BODIES A method and apparatus for reducing the cross-section of a terminal portion of a tubular body said apparatus comprising an external die which defines a convergent work surface therein of like shape to the exterior of the reduced cross-section to be produced; a plug having a work surface thereon of like shape to the interior of the reduced cross-section to be produced; means to hold the plug in axial alignment with the die during relative motion as between the plug and die to centre the plug within the die to define a pass gap of shape and gap width substantially equal to that shape and thickness of the reduced cross-section; means to enter the terminal portion of the tubular body into the pass gap between the plug and die; and means to cause the die to vibrate in a radial mode at an ultrasonic frequency while the terminal portion is progressively reduced to the shape of the pass gap.