BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
FIG. 1 is a partial perspective view of the basic single-layered web beam of the invention, taken from above.
FIG. 2 is a partial perspective view of the beam of FIG. 1, taken from below.
FIG. 3 is a cross sectional view of a prior art beam with a double-layered web.
FIG. 4 is a cross sectional view of a prior art beam with a single-layered web.
FIG. 5 is a cross sectional view of the beam of the invention.
DETAILED DESCRIPTION OF THE INVENTION
Beams 20 for suspended ceilings are shown in FIGS. 1 through 5. Such beams include the prior art beams shown in FIGS. 3 and 4, and the single-layered web beam of the invention shown in FIGS. 1, 2, and 5. Beams 20 have a bulb 21 at the top of a web 22. Opposing flanges 23 and 25 extend horizontally away from the web at the bottom of the beam.
The vertical panel load, or vertical drywall load, on the beams in a suspended ceiling, is indicated in FIGS. 3 through 5 by vectors that represent the amount, location, and direction of the load exerted by the panels or drywall in a suspended ceiling. The load on each flange is indicated by numbers 26 and 27 on the prior art beams shown in FIGS. 3 and 4, and on the beam of the invention 20 shown in FIG. 5.
The prior art beam 20 shown in FIG. 3 has a two-layered web 22, with each of the flanges 23 and 25 cantilevered from one of the layers of the web 22. The beam is symmetrical, and hence balanced, in cross section.
The prior art beam 20 shown in FIG. 4 has a single-layered web 22 with a flange 25 cantilevered from the bottom of the web 22, to the right, and then a second opposing flange 23 cantilevered from flange 25 at location 29, in a direction to the left.
The basic single-layered web beam 20 of the invention, as seen in FIGS. 1, 2, and 5, has a single-layered web 22, with the flanges formed as in the prior art beam 20 of FIG. 4. The basic single-layered web beam 20 of the invention also has a seam 40 that runs longitudinally along the web 22 of the beam, that binds flanges 23 and 25 together, so that flange 23 is cantilevered from flange 25 along web 22.
The seam 40 is preferably made as the beam is being continuously rollformed, as by stitching. A form of stitching is disclosed in U.S. Pat. No. '055 cited above. A seam 40 could also be formed by continuous or spot welding, or by adhesives.
Seam 40, in effect, cantilevers the flange 23 from the single-layered web 22 of the basic beam of the invention 20, so that the result is a balanced beam that is loaded through the plane of the single-layered web 22. Such basic beam 20 of the invention resists twisting and bending to an extent equivalent to that of a double-layered web beam of a comparable size made of the same thickness metal strip, as seen for instance in FIG. 3. The beam of the invention however, uses less metal.
In FIGS. 3, 4, and 5 of the drawings, the loading of the beams 20, both prior art, and of the invention, is shown through the use of vectors.
In FIG. 3, load vectors 26 and 27 represent the vertical loading on each of the flanges 23 and 25 of a double-layered prior beam 20, in either a panel or a drywall suspended ceiling. The resultant load vector 30 of vectors 26 and 27 of such prior art double-layered web beam passes through the plane of web 22, since the beam is balanced. Such balanced beam creates a maximum resistance to bending and twisting.
In FIG. 4, there is shown the single-layered beam of the prior art. Again, as in FIG. 3, the vectors 26 and 27 represent the loads applied to the beams, either through panel, or drywall, loads. However, because of the beam construction wherein flange 23 is cantilevered from flange 27 at location 29, the resultant load vector 31 is shown applied at a distance away from the single-layered web, resulting in an unbalanced beam subject to bending and twisting that is not present in the balanced beam of FIG. 3.
In FIG. 5, which shows the basic single-layered web beam 20 of the invention, again, as in the prior art, the beam 20 is vertically loaded on the flanges 23 and 25, in the suspended ceiling, as shown by vectors 26 and 27. However, seam 40 binds flange 23 to flange 27 along web 22, so that in effect both flanges 23 and 25 are cantilevered from web 22, resulting in a balanced beam. Load resultant 32 passes through the plane of the web, so that the single-layered beam of the invention resists twisting and bending equivalent to a comparably sized two-layered web beam, as seen in FIG. 3, but with the use of less metal.
Patent Application
20070277466
