| 摘要 |
<p>METHOD OF FORMING A THIN WALLED ANNULAR CHANNEL A method of forming a thin walled annular channel or semitoroidal shell from a flat rectalinear sheet, including forming the sheet into a cylindrical band and welding or otherwise securing the abutting free ends of the band. The cylindrical band is then forced into a die set having a cylindrical opening which smoothly blends into an inwardly curving semi-toroidal space defined by opposed concave and convex die surfaces. The cylindrical band is curled inwardly and compressed by the die surfaces, accurately conforming the band and the weldment to the outer concave die surface and eliminating tensile fracture of the weldment.</p> |
