US 3,940,965 A · Method and apparatus for forming corrugating pipe

Abstract

A corrugated pipe forming apparatus and method in which flat sheet metal is passed through a plurality of first and second opposite roller pairs and deformed into a corrugated sheet. Lateral lips are formed parallel to the edges of the sheet and extend generally perpendicular to the sheet over the full length thereof. A pipe rolling machine helically deforms the corrugated sheet and folds the lip into a mechanical lock seam defining Pittsburgh lock of predetermined dimensions and tolerances. To maintain such dimensions and tolerances the width of the lips is adjusted by simultaneously moving one roll of each set in identical increments towards and away from the other roll of each set to thereby correspondingly change the depth of the corrugations and the width of the lips. The sheet can be moved laterally to maintain the lips of equal width. Corrugating stations of the device are defined by opposed corrugating rollers with the upper rollers held on a first frame and the lower rollers held on a second frame. Each frame includes opposite and rigid sides interconnected by fixed rigid axles. Opposed upper and lower rollers are journaled at their respective ends about each of the respective axles.

Claims19

Dependent claims

In a line mill having a plurality of opposed overlying and underlying working rollers for corrugating a skelp strip passing therebetween, means for forming a longitudinal edge lip extending over the length of the corrugated strip, a power source for driving the rollers to corrugate the skelp, and adjustment means for varying the working dimension between the upper and lower opposed rollers to conform to various dimensions, thicknesses and deformabilities of skelp, the improvement comprising:

means for maintaining the width of the lip substantially constant, the last mentioned means including a first frame for supporting all of the overlying rollers;
first shaft means fixedly carried by the first frame and mounting the overlying rollers for rotation about an axis of the first shaft means;
a second frame for supporting all of the underlying rollers;
second shaft means fixedly carried by the second frame and mounting the underlying rollers for rotation about an axis of the second shaft means;
adjustment means for urging the first and second frame members with the respective attached overlying and underlying rollers towards one another;
and means for simultaneously and identically operating the adjustment means to move the respective frame sections towards and away from one another to produce simultaneous and identical adjustment between all of the overlying and underlying rollers whereby the activation of the operating means moves the frame sections towards or away from each other to compensate for skelp strip width variations and to thereby maintain the lip width constant irrespective of such variations in the skelp width.

3 more elements

A corrugated pipe forming apparatus comprising:

a plurality of first rolls and a like plurality of opposite second rolls for longitudinally passing flat sheet metal therebetween and for deforming the flat sheet into a longitudinally corrugated sheet;
means for forming lateral edge lips parallel to edges of the flat sheet metal, the lips extending over the full length of the sheet and generally transversely to a remainder of the sheet;
a pipe rolling machine including means for helically winding the corrugated sheet and means for continuously folding the lips over each other to form a mechanical lock seam securing the edges of the helically wound strip and thereby forming a continuous pipe seam defining a Pittsburg lock of predetermined dimensions and tolerances;
means for adjusting the width of the lips comprising means for simultaneously moving the rolls of each set in identical increments towards or away from each other to correspondingly change the depth of the corrugations formed in the flat sheet and to thereby correspondingly change the width of the lips, and actuating means for effecting the simultaneous and identical movement of the rolls;
whereby the widths of the lips can be continuously monitored and changed in response to variations in the sheet width or thickness to maintain the Pittsburgh lock within said dimensions and tolerances.

2 more elements

A method for forming corrugated pipe from flat sheet metal by helically winding corrugated sheet metal and forming an interlocking seam along edges of the helically wound sheet metal, the method comprising the steps of:

passing the flat sheet metal through a plurality of sets of corrugating rollers;
helically deforming the corrugated sheet and cylindrically winding it about an axis which is angularly inclined relative to the direction of movement of the sheet through the corrugating rollers, the angle being a function of the pipe diameter and the corrugated sheet width;
continuously interconnecting the edges of the helically wound sheet to form a continuous pipe seam;
monitoring the formation of the pipe seam, and intermittently changing the width of the corrugated sheet to compensate for deviations in the width due to irregularities or dimensional changes in the flat sheet by identically moving one of the rollers of each set towards or away from the other roller of each set to thereby correspondingly change the depth of the corrugation and the overall width of the sheet.

1 more element

Dependencies are inferred from the claim text.

Method and apparatus for forming corrugating pipe

Life of this patent

Method and apparatus for forming corrugating pipe

Life of this patent

Abstract

Claims19