Elbow-making machine

Mechanism for cutting ends on circularly cylindrical pipe, said pipe having a longitudinal axis and a peripheral wall, said mechanism comprising:

• a frame;
• collet means to grip and to rotate the pipe around its longitudinal axis;
• a collet shaft to support and turn said collet means;
• drive means to turn said collet shaft;
• cutter means having a cutting edge to cut the wall of said pipe;
• cutter mounting means supporting said cutter means, said cutter mounting means rotatably mounting the cutter means for rotation of its cutting edge around its point of contact with a pipe being cut;
• supporting means mounting one of said collet shaft or cutter mounting means for axially shifting the same;
• positioning means for moving the supporting means and cutter mounting means to make a cut in the pipe, with the cutter means substantially aligned with its cutting path, said positioning means comprising:
• wobble means mounted to said collet shaft having a wobble axis at a reference angle to the axis of rotation of the collet shaft, whereby a plane normal to the wobble axis, when turned around the axis of rotation, is tangent to a cone;
• a converter comprising an embrasure which grips the wobble means and enables it to slide therein, rocking embrasure mount mounting the embrasure for rotation with the wobble means, and slave means interconnecting the embrasure and the cutter mounting means, whereby the angular position of the cutter means corresponds with the angular position of the wobble means, one of said collet shaft or the embrasure mounting being restrained to the base against axial movement, the other being axially shiftable relative to the base, whereby the relative axial position of the cutter means and of the collet is a function of the angular position of the wobble means.