Apparatus for the continuous manufacture of hollow tubular elements

An apparatus for continuously manufacturing hollow tubular elements, comprising an elongated central core having a longitudinal axis and one end portion connectable with drive means to be rotated about said longitudinal axis;

• a plurality of supporting elements projecting circumferentially outwardly from said central core and longitudinally spaced along the same, each supporting element being provided with a plurality of guiding means circumferentially distributed around the same and axially aligned with one another;
• a cam element forming a cam surface arranged circumferentially about said longitudinal axis of said core and extending in a plane which is helical with respect to a plane transverse to said axis;
• a plurality of rod elements forming a substantially cylindrical molding surface, said rod elements being arranged in side-by-side relationship and extending longitudinally over the entire length of said central core in a circumferentially spaced relationship with the latter, said rod elements being aligned on said supporting elements and guided in an individual cyclic displacement by said guiding means, each of said rod elements being arranged immediately following said cam element and urged against said cam surface of the latter, said cam element with said surface being supported in a non-revolving manner on said central core so that during the rotation of said central core said cam surface remains immovable, whereby when each rod element is being displaced cyclically and biased against said immovable cam surface, it will perform a movement of extension and retraction in the direction of said longitudinal axis of said core, so that a continuous strip of a tubular body forming element can be wound helically about said molding surface with constant advance of one spiral with respect to the other and with a pitch between spirals equal to the width of the continuous strip, minus a marginal overlap portion.