Apparatus for manufacturing a metal pipe

• US 4,491,004 A
• Filed: 04/16/1982
• Issued: 01/01/1985
• Est. Priority Date: 08/18/1980
• Status: Expired due to Term

• Current Assignee: Aliko Limited Alitalo's Engineering Works
• Original Assignee: Osmo O. Ivanoff
• Inventors: Ivanoff, Osmo O.
• Primary Examiner(s): Combs, E. Michael
• Application Number:
  US06/373,505
• Time in Patent Office: 991 Days
• Field of Search: 72/51, 72/169, 72/170, 72/171, 72/173, 72/175, 72/212, 72/213, 72/389, 72/412, 72/368, 72/465, 72/466, 72/168
• US Class Current: 72/168
• CPC Class Codes: B21C 37/0815 without continuous longitudinal movement of the sheet during the bending operation
• CPC Class Codes: B21D 5/14 by passing between rollers B21D5/06 takes precedence

Abstract

The invention relates to an apparatus for manufacturing a metal pipe. At present, accurately measured, thick-walled pipes to be used as rolls must be manufactured in a plurality of working steps. The manufacture of pipes of accurate diameters is complicated e.g. due to inner stresses in pipe blanks which results in deformations in internal or external machining of pipes. An object of the present invention is to overcome the drawbacks of the prior art. According to the invention a metal sheet is bent into the shape of a pipe by applying to said sheet a bending force perpendicularly to the sheet along a longitudinal line of action (a) in the sheet by means of a bending tool (2), said sheet being supported on a support tool (3) along two support lines (b, c) parallel to said line of action which lies between said support lines, the sheet being laterally displaced, so that the bending line and support lines move along the sheet in its lateral direction, and that the edges of said sheet are bent against each other and welded together. Said sheet (1) may be bent by means of a bending roll (4) against two support rolls (5, 5'"'"'). The apparatus of the invention consists of a bending tool (2) e.g. comprising a bending roll (4), and a support tool (3), e.g. two parallel rotatable support rolls (5, 5'"'"') supported at a distance from each other, wherein bending roll is parallel to said support rolls and can be moved towards the support rolls by means of an actuator (11).

Claims

1. An apparatus for fabricating a tubular article from a metal sheet, comprising a base, a top support mounted for movement with respect to said base, a support tool mounted on the base and comprising at least two spaced parallel rotatable support rolls, bending tool means mounted on said top support and comprising at least one bending roll disposed parallel to said support rolls, drive means for moving a metal sheet between said bending roll and said support rolls in a direction transverse to the longitudinal dimension of said rolls wherein said metal sheet is bent into tubular shape by applying a bending force through said bending roll along a longitudinal line located between said support rolls, first spring roller means supporting said bending roll from said top support, second spring roller means for mounting each of said support rolls with respect to said base, said first and second spring roller means permitting rotation of said rolls and corresponding transverse movement of said sheet, means for applying a force to said bending roll sufficient magnitude to overcome the force of said first and second spring means and provide a rigid mounting for both said support rolls and said bending roll during the bending operation to bend said sheet to form said tubular article, and actuator means for moving said bending roll into contact with the outer surface of said tubular article whereby the article is supported for rotation for subsequent processing by said support rolls and said bending roll.

2. The apparatus of claim 1, and including a support member disposed between the support rolls and aligned with said bending roll and having a generally concave upper surface against which the edge portion of said sheet is bent, said support member being constructed and arranged to be moved in a direction away from said bending roll to a position out of engagement with the tubular article to enable said article to be supported for rotation solely by said support rolls and said bending roll.