Patent ID: 6247634
Filing Date: 2001-06-19
Classification: B23K

Abstract:
A method of stir welding together two cylindrical end portions of large, thin-walled tank sections composed of like metallic material which abut one another at a cylindrical joint,assembling within said tank sections an anvil assembly including a multipart anvil ring having a center axis and an outer cylindrical anvil surface such that the inside wall of said cylindrical end portions engage said anvil surface at said joint,applying a high endwise force to a stir welding tool along a line of force passing through said joint and axis while turning said tool about a rotational axis coinciding with said line of force and while moving said tool and tank sections relative to one another along said cylindrical joint with said tank sections being stationary relative to said anvil ring to thereby stir weld the tank sections together at said joint,maintaining a reactive force against the outside of said edge portions at said joint at a location diametrically opposite to said tool so as to press said edge portions against said anvil surface at said location and oppose said endwise force while said tank sections are being stir welded together, anddisassembling said anvil assembly and removing the disassembled parts of said anvil assembly through an access opening at the conclusion of the stir welding.