Abstract An improved cold formed, sheet metal profiled building unit and method of making the same are disclosed. The building unit incorporates at least one longitudinal stiffening rib in a longitudinal flat region of the type having a tendency to buckle when subjected to compressive forces. The longitudinal stiffening rib is formed not by drawing-in sheet metal as in current roll forming practices, but, instead, by stretching a segment of the sheet metal. Each longitudinal rib has a profile width, as measured along the centerline of the rib, which is greater than the linear of the sheet metal segment from which it was stretched-in. Roll forming machines incorporating the principles of this invention utilize fewer roll stands than do roll forming machines incorporating the principles of current roll forming practices.
In a profiled building unit formed from sheet metal having a substantially uniform sheet thickness and presenting alternating crests and valleys, and sloped webs connecting adjacent ones of said crests and said valleys, the improvement comprising: first and second stiffening ribs formed, respectively, in said crests and said valleys, said stiffening ribs extending longitudinally along substantially the entire length of said building unit and each having a substantially uniform rib thickness that is less than said uniform sheet thickness of said metal sheet.
Claim 2
Dependent Claim
83 words
In a profiled building unit formed from sheet metal having a substantially uniform sheet thickness and presenting alternating crests and valleys, and sloped webs connecting adjacent ones of said crests and said valleys, the improvement comprising: first and second stiffening ribs formed, respectively, in said crests and said valleys, said stiffening ribs extending longitudinally along substantially the entire length of said building unit and each having a substantially uniform rib thickness that is less than said uniform sheet thickness of said metal sheet.
Claim 3
Dependent Claim
47 words
The building unit as defined in claim 1 including third stiffening ribs formed in said webs, extending longitudinally along substantially the entire length of said building unit and each having a substantially uniform rib thickness that is less than said uniform sheet thickness of said metal sheet.
Claim 4
Dependent Claim
31 words
The building unit as defined in claim 1 wherein only those of said valleys disposed between adjacent ones of said crests each include at least one of said second stiffening ribs.
Claim 5
Dependent Claim
52 words
The building unit as defined in claim 1 or 2 wherein the firth of said sheet metal is less than that required to produce a decking unit identical in profile to said building unit but with stiffening ribs having a rib thickness substantially equal to said uniform thickness of said sheet metal.
Claim 6
Dependent Claim
16 words
The building unit as defined in claim 1 or 2 wherein said stiffening ribs are stretched-in.
Claim 7
Dependent Claim
39 words
The building unit as defined in claim 1 or 2 wherein each of said stiffening ribs has a profile width that is greater than the linear width of the segment of said sheet metal from which each was stretched-in.