US 5,176,019 A · Forming of metal structural members

Abstract

A structural member having a complex shape, such as a return flange z-shape, is manufactured by confining a longitudinally-extending mid-portion of a metal strip between a pair of forming mandrels and running the mandrels and the strip as a unitary workpiece from pass-to-pass of a roll forming machine progressively to form the sheet metal about surfaces of both mandrels. The metal strip and the formed part may have a uniform thickness or may have varying thicknesses. The cross-sectional distribution of the metal mass along the length of the structural member may be modified from the original strip. The structural member may have one or more joggles using a mandrel or mandrels having a complementary recess for each joggle to be formed. In such case, one or more of the passes includes a forming roll assembly that is strongly biased, and or resiliently self-biased, toward each recessed portion of the mandrel to force the sheet metal into each such recess to complete the formation of a joggle. Joggles may be formed in structural members having shapes other than z-shapes. Equipment used in the manufacture of the structural members includes roll stands having appropriately-shaped forming rolls with surfaces that may move vertically, horizontally, or in other directions as needed to accommodate the shapes of the structural members to be formed.

Claims14

Dependent claims

A method for forming from an elongate sheet metal blank a one-piece, elongate, non-planar structural member, said method comprising the steps of:

providing a pair of elongate, rigid, forming mandrels, each of said forming mandrels having longitudinally-extending part-forming surfaces contoured to form parts of said structural member, and each of said forming mandrels having longitudinally-extending roll-engaging surface means for engaging upper and lower roll means at passes of a roll forming machine;
forming a workpiece comprising said forming mandrels in mutually confronting relation with a portion of said sheet metal blank positioned therebetween;
equiping a roll forming machine with a plurality of passes each of which has upper rolls and lower rolls, the upper rolls and the lower rolls of at least respective ones of said passes having contours differing from the contours of the corresponding rolls of at least some other passes, said rolls being configured to progressively form said blank over portions of said part-forming surfaces of said mandrels as said strip moves from pass to pass;
and
shaping parts of said sheet metal blank to predetermined contours matching said portions of said part-forming surfaces by passing said workpiece through said roll forming machine and thereby engaging said roll-engaging surface means of both of said mandrels by said rolls and thereby also engaging portions of said blank by said rolls to progressively form portions of said blank against portions of said part-forming surfaces of both of said mandrels.

2 more elements

A method for forming from an elongate sheet metal blank a one-piece, elongate, Z-shaped structural member having a generally vertical middle leg, a generally horizontal upper leg, a generally vertical upper return flange extending along and projecting downwardly from said upper leg, a generally horizontal lower leg, and a generally vertical lower return extending along and projecting upwardly from said lower leg, said method comprising the steps of:

providing a pair of elongate, rigid, forming mandrels, each of said forming mandrels having longitudinally-extending part-forming surfaces contoured to form parts of said Z-shaped section, said part-forming surfaces of one of said mandrels being contoured to form portions of at least one of said legs and said part-forming surface of the other of said mandrels being contoured to form portions of at least the other of said legs, and each of said forming mandrels having longitudinally-extending roll-engaging surfaces for engaging upper and lower rolls at the passes of a roll forming machine;
forming a workpiece comprising said forming mandrels in mutually confronting relation with a portion of said sheet metal blank positioned therebetween;
equiping a roll forming machine with a plurality of passes each of which has upper rolls and lower rolls, the upper rolls and the lower rolls of at least respective ones of said passes having contours differing from the contours of the corresponding rolls of at least some other passes, said rolls being configured to progressively form said blank over portions of said part-forming surfaces of said mandrels as said strip moves from pass to pass;
and
shaping parts of said sheet metal blank to predetermined contours matching said portions of said part-forming surfaces by passing said workpiece through said roll forming machine and thereby engaging said roll-engaging surface means of both of said mandrels by said rolls and thereby also engaging portions of said blank by said rolls to progressively form portions of said blank against portions of said part-forming surfaces of both of said mandrels.

2 more elements

Dependencies are inferred from the claim text.

Forming of metal structural members

Life of this patent

Forming of metal structural members

Life of this patent

Abstract

Claims14