Method and apparatus for forming spiral tubing
AssigneeGA Technologies Inc.
InventorsJack S. Yampolsky, Endre F. Peszeszer
Life of this patent
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Abstract
A method and apparatus for forming a spiral tube from a length of metallic strip material wherein the strip is fed through a closed tube forming die operative to form the strip into a spirally wound tube having its longitudinal edges in juxtaposed relation. Driven torque wheels carried on one or more support carriages downstream from the forming die are operative to engage the outer peripheral surface of the tube to prevent springback and enable selective control of the relation between juxtaposed edges of the strip as it is passed longitudinally through a welding station during which the juxtaposed edges are welded to form a continuous leak-proof seam. The metallic strip may be planar or have longitudinal flutes formed therealong.
Claims9
Apparatus for forming spirally wound unperforated tube with an uninterrupted leakproof welded seam without flanges thereon from metallic strip material having parallel laterally spaced longitudinal edges, said apparatus comprising, in combination,
- frame means,
- tube forming die means supported by said frame means and defining a substantially cylindrical bore therethrough having an entrance end and an exit end,
- means for feeding a length of said metallic strip material into said entrance end of said die means in a direction such that the longitudinal axis of the strip subtends a predetermined acute angle with the axis of said bore, said feeding means being operative to advance said strip material through said cylindrical bore in a manner to form a spiral tube having said longitudinal edges in juxtaposed relation,
- said tube forming die means being of the closed tube kind including a cylindrical wall therein defining the substantially cylindrical bore for forming the tube solely by contact with said cylindrical wall,
- welding means supported by said frame means to receive said spiral tube from said die forming means and weld said juxtaposed edges so as to form an uninterrupted leakproof, continuous seam between said juxtaposed edges, and
- torquing means supported by said frame means and including a plurality of driven torque wheels adapted to apply a torque to said spiral tube in a manner to selectively control the relationship between said juxtaposed edges of said spirally wound tube during welding of said spiral tube, said torquing means comprising at least three torque wheels equally spaced about the circumference of said spiral tube and opposed to each other and having frictional contact with the spirally wound tube adjacent the closed tube forming die means to hold the longitudinal edges within the tube forming means and to reduce springback at the exit of the tube forming means and thereby reduce the force of the tube on the cylindrical wall forming the tube.
A method for forming a spiral unperforated tube with an uninterrupted leakproof welded seam without flanges thereon from metallic strip material having parallel laterally spaced longitudinal edges, said method comprising the steps of;
- feeding said metallic strip into a closed tube forming means having a wall defining a substantially cylindrical bore such that said strip enters said bore generally tangentially thereto and with the longitudinal axis of the strip subtending an acute angle with the longitudinal axis of said bore, and progressively advancing said strip through said bore so as to form said strip into spirally wound tube with said longitudinal edges in juxtaposed relation without the use of moving parts,
- applying a predetermined torque to the outer peripheral surface of said spirally wound tube from at least three driven torque wheels to hold the longitudinal edges within said tube forming means so as to reduce the force of the tube on the cylindrical wall and so as to prevent springback of the spirally wound strip after passing from said cylindrical bore and maintain said juxtaposed edges in predetermined relation to each other, and
- welding said juxtaposed longitudinal edges of said strip so as to form a substantially continuous seam along the length of said spiral tube and applying a predetermined torque to the welded seam.
Dependencies are inferred from the claim text.