Roll forming of sheet metal

Claim 3

A method according to claim 1 wherein two of the said further initial ribs are formed in the second roll stand, one to each side of the said first initial rib.

Claim 4

A method according to claim 1 wherein each of the profiles subsequently formed from the said initial ribs is a pair of ribs, the said first initial rib being reformed into a pair of ribs in the second roll stand and the said at least one further initial rib being reformed into a pair of ribs in a third roll stand.

Claim 5

A machine for the draw roll forming of a plurality of longitudinally extending profiles in a metal sheet passed continuously through the machine including a first roll stand having cooperating male and female forming rolls, a second roll stand having cooperating male and female forming rolls, the said male forming rolls of the first roll stand having a radially projecting part which cooperates with a radially recessed part in the female roll of the first roll stand to form an initial rib in the sheet as it passes through the first roll stand, the said male-forming roll of the second roll stand having at least one radially projecting part which cooperates with a radially recessed part of the female roll of the second roll stand to form a further initial rib in the sheet as it passes through the second roll stand, the further initial rib being spaced laterally from the said first initial rib, the said rolls of the second roll stand having cooperating parts which reform the said initial rib formed by the first roll stand without drawing in further metal from the rest of the sheet, there being an axially extending coaxial support flange adjacent each side of each said radially projecting part, the diameter of at least one of the support flanges adjacent each said radially projecting part decreasing with distance from the said radially projecting part, the radially projecting part and the support flanges of the male roll and the radially recessed part on the female roll assisting in the transformation of the sheet as it approaches the roll stand into a valley cross-section having an apex portion which provides the strip of sheet from which the initial rib is formed as it passes through the roll stand.

Claim 6

A machine for the draw roll forming of a plurality of longitudinally extending profiles in a metal sheet passed continuously through the machine including a first roll stand having cooperating male and female forming rolls, a second roll stand having cooperating male and female forming rolls, the said male forming rolls of the first roll stand having a radially projecting part which cooperates with a radially recessed part in the female roll of the first roll stand to form an initial rib in the sheet as it passes through the first roll stand, the said male-forming roll of the second roll stand having at least one radially projecting part which cooperates with a radially recessed part of the female roll of the second roll stand to form a further initial rib in the sheet as it passes through the second roll stand, the further initial rib being spaced laterally from the said first initial rib, the said rolls of the second roll stand having cooperating parts which reform the said initial rib formed by the first roll stand without drawing in further metal from the rest of the sheet, there being an axially extending coaxial support flange adjacent each side of each said radially projecting part, the diameter of at least one of the support flanges adjacent each said radially projecting part decreasing with distance from the said radially projecting part, the radially projecting part and the support flanges of the male roll and the radially recessed part on the female roll assisting in the transformation of the sheet as it approaches the roll stand into a valley cross-section having an apex portion which provides the strip of sheet from which the initial rib is formed as it passes through the roll stand.

Claim 7

A machine according to claim 4 wherein the said radially projecting part on each of the said male forming rolls has an arcuately curved periphery as seen in axial cross-section whereby the initial rib formed has an arcuate cross-section.

Claim 8

A machine according to claim 4 wherein each of the said female forming rolls has a coaxial flange at each side of the said radially recessed part, which flanges are opposed to and parallel to the said flanges of the respective male rolls in the nip of the male and female rolls, the flanges being spaced in the nip to allow metal to be freely drawn in laterally during the formation of the initial rib.

Claim 9

A machine according to claim 4 wherein the said cooperating parts of the rolls of the second roll stand which reform the initial rib formed in the first roll stand, are shaped to form a pair of ribs from the initial rib, there being a third roll stand having rolls including cooperating parts which reform the said at least one initial rib formed in the second roll stand into a further pair of ribs.

Claim 10

A machine according to claim 4 wherein the male roll of the second roll stand has two of the said radially projecting parts, one to each side of the part which reforms the initial rib made in the first roll stand, whereby two further initial ribs are formed in the second roll stand.