Structural elements

3,282,005

Nov. 1, 1966

B. F. BIRDWELL

STRUCTURAL ELEMENTS

Filed June 11, 1963

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INVENTOR.

BENJAMIN E BIRDWELL

BY

United States Patent Office

3,282,905

Patented Nov. 1, 1966

3,282,005 STRUCTURAL ELEMENTS

Benjamin F. Birdwell, Memphis, Tenn., assignor to Benco, Inc., Memphis, Tenn., a corporation of Tennessee

Filed June 11, 1963, Ser. No. 286,988

Claims. (Cl. 52—364)

This invention relates to structural elements, and more particularly relates to such elements adapted to be used in the roof and floor systems of buildings, and as studs in the walls of buildings.

Heretofore, architectural building designs have dealt, for the greater part, with walls. Floor and roof systems have been neglected since they provide function rather than esthetics. Excessive costs of roof and floor systems have been accepted by architects and builders; however, these parts of a building provide the greatest opportunity for savings. Modern architectural trends are towards flat roofs. Service stations, schools and industrial buildings require clear spans. Conventional roof systems consist generally of four members: (1) joists (independently erected); (2) deck (independently attached); (3) ceiling (independently applied by suspending or by applying lathes, plastering and painting); and (4) mop-on (applying felt waterproof membranes). Previously, there have been a number of free span roof systems introduced. For example, several types leave open cells which require the addition of special ceilings. Another type requires the addition of a deck in order to provide a surface upon which the roof can be applied. These systems carry a transverse section of heavy gauge in order to provide proper metal thickness for the beam section. These prior systems were expensive to manufacture, expensive to pack, and expensive to erect.

The present invention is primarily directed towards overcoming the above mentioned and other disadvantages in prior roof and floor systems.

Thus, one of the principal objects of the present invention is to provide a roof and floor system that is less expensive than previous systems, yet is highly effective.

A further object is to provide such a system that is easy for non-experienced personnel to erect.

A further object is to provide such a system that is long-lasting and substantially maintenance free.

A further object is to provide a metal roof and floor system that simulates a wooden system and is attractive in appearance.

A further object is to provide such a system that includes a unique metal box beam having provisions for receiving attaching members as nails and the like, deck members supported by said box beam, and attaching members as nails or the like extending through said deck members and into said box beam.

A further object is to provide improved means in such a beam for positively and tightly holding the attaching members.

A further object is to provide such a box beam which is shaped in an optimum form to have the maximum strength for a unit weight.

A further object is to provide such a beam that is easy to handle and erect.

A further object is to provide such a beam that is economical to fabricate, economical to transport, and economical to erect.

A further object is to provide such a beam that, in addition to being useful in a roof and floor system, can be used as a stud in a building wall.

A further object is generally to improve the design and construction of structural elements.

The means by which the foregoing and other objects of the present invention are accomplished and the manner of their accomplishment will be readily understood from the following specification upon reference to the accompanying drawings, in which:

FIG. 1 is a perspective view of one of the box beams of the present invention.

FIG. 2 is an enlarged cross-sectional view of the beam shown in combination with a deck member and an attaching member nailed through the deck member and into the box beam.

FIG. 3 is a fragmentary plan view of the box beam showing a step in the process of constructing same.

FIG. 4 is an enlarged fragmentary sectional view taken as on the line IV—IV of FIG. 3.

Referring now to the drawings in which the various parts are illustrated by numerals, the structural system 11 of the present invention includes, in general, the combination of the box beam 13, a member for attaching to the box beam such as the deck member 15, shown in FIG. 2, and an attaching member such as the helix drive nail 17.

Referring now in more detail to box beam 13, it includes two sections or halves 19, 21, which are substantially identical in construction except that in assembled relationship the halves are disposed 180 degrees relative to one another. The halves 19, 21 are respectively Cshaped in cross-section and inwardly face towards one another where they are interlockingly joined together, as will be better understood in the description to follow.

Half 19 is preferably formed of one piece of suitable material such as steel and is formed into the shape best seen in FIG. 2, wherein it will be seen the half 19 comprises a side wall 23 and spaced upper and lower walls, 25, 27 respectively extending substantially perpendicular from the upper and lower edges of side wall 23 and respectively terminating in upper and lower distal edges 29, 31. In addition, half 19 includes a substantially U-shaped member 33 integrally attached to upper wall 25 along the distal edge 29 thereof. In forming U-shaped member 33, the distal edge 29 is preferably rounded somewhat, as best seen in FIGS. 2 and 4. From the distal edge 29 the portion 35 of the U-shaped member depends downwardly and slightly inwardly, and then the U-shaped member is curved for a portion as at 37 from where it extends upwardly for a portion as at 39. This latter mentioned portion 39 preferably terminates below the level of upper wall 25 and is flared slightly outwardly away from side wall 23. Also, half 19 includes an upstanding flange 41 integrally attached to lower wall 27 along the distal edge 31 thereof. It will be noted from FIG. 2 that the flange 41 angles somewhat inwardly towards side wall 23. As distal edge 29, the distal edge 31 is also somewhat rounded, as best seen in this figure.

Half 21 is identical with half 19, and includes side wall 43 and walls 45, 47 extending perpendicularly from the side wall adjacent the lower and upper edges thereof. As heretofore stated, the only difference between the two halves 19, 21 is in the positioning thereof at 180 degrees relative to one another so that wall 47 is the upper wall from which the flange 49 depends and wall 45 is the lower wall from which the inverted U-shaped member 51 upstands.

The advantages of the above-mentioned construction relative to shipping can readily be appreciated when it is considered that the two halves 19, 21 can be nested to reduce the amount of space required in shipping. Then, when it is desired to assemble box beam 13, for example, at the construction site, the half 21 is turned 180 degrees and brought into interlocking engagement by insertion of flange 49 into U-shaped member 33 and insertion of flange 41 into inverted U-shaped member 51. The parts are so arranged that when brought into the interlocking engagement above described, the distal edge 29 of half 19 and the adjacent distal edge 53 of half 21 are

3,282,005 in close adjacency, as seen in dotted lines in FIG. 4, and the flange 49 and U-shaped member 33 are in engagement. In a like manner, the distal edge 31 of half 19 and the adjacent distal edge 55 of half 21 are in close adjacency, and flange 41 is in engagement with inverted U-shaped member 51.

The next step in the assembly of box beam 13 is to put U-shaped member 33 and flange 49, and the inverted U-shaped member 51 and flange 41, respectively, under tension by spreading apart edges 29 and 53, and edges 31 and 55. It will be understood that the spreading apart of the edges as above described puts the parts under tension since they are formed of resilient material. Also, when the edges are spread apart as above described, grooves 57, 59 will respectively be established between the edges. Thus, upwardly opening groove 57 will be established longitudinally of the beam in the middle of the upper wall 61 of the beam. It will be understood that upper wall 61 of beam 13 is established from the upper walls 25, 47 of the respective halves 19, 21. Likewise, downwardly opening groove 59 is established longitudinally in the middle of the lower wall 63 of box beam 13, which lower wall is established from the lower walls 27, 45 of the halves.

The preferable means for spacing edges 29, 53 and edges 31, 55 is by shims 65 interposed between the adjacent edges at spaced intervals. Then, the halves 19, 21 are tack-welded as at welds 67 interposed between the edges at spaced intervals. Shims 65 may be either left in or removed after welds 67 have been provided.

To complete the system 11, members, such as deck members 15 which are supported on upper wall 61 over groove 57, are attached to beam 13 by driving attaching members, such as helix nails 17, through deck member 15 and into groove 57. It will be understood that, if desired, other members may be similarly attached to beam 13 along lower wall 63 as by driving attaching members into groove 59. It will also be understood that when the attaching members, as nails 17, are driven into the grooves 57, 59, the edges 29, 53 and the edges 31, 55 will be slightly spread apart by the nails against the inward compressing force caused by the action of U-shaped member 33 and flange 49, and U-shaped member 51 and flange 41. This inward compressing force against the attaching member, as above described, is an important part of the present invention since it will be understood the attaching members are thereby clamped in tight engagement so that they will not fall out or be easily removed. Also, the importance of this can be appreciated when it is considered that if the compressive force were not present and the welds 67 were used to hold the halves 19, 21 together, then the welds could easily be broken and there would be no compressive force to hold the attaching members in place. In contrast to this, with applicant’s structure, it would make no difference if welds 67 did break when the attaching members were driven into the groove, as, for example, in close proximity to a weld, since the attaching member would then act as the spacer means.

It should be pointed out that helix nails 17 are preferably of the type which are symmetrical, that is, root portions of the threads on one side of the nail correspond with root portions on the opposite side of the nail, with the corresponding root portions being directly across from each other. This makes possible the entrance of the edges 29, 53 and the edges 31, 55 into opposite root portions of the nails so that the nails are tightly held substantially perpendicular to walls 61 and 63. In other words, it is not necessary to rely strictly on the friction between the nail and the above-mentioned edges as would be the case if ordinary smooth nails were used, but with the use of the symmetrical helix nails the friction of the edges against the nails prevents them from rotating, and : the edges extending into the roots of the threads hold the nails against withdrawal from the grooves in the beam.

From the foregoing description it will be understood that the present invention provides a unique and highly effective structural system for buildings in which a unique box beam is provided. It will further be understood that this system is one in which a roof and floor system can be erected much quicker and more economically than heretofore possible.

Although the invention has been described and illustrated with respect to a preferred embodiment thereof, it is to be understood that it is not to be so limited since changes and modifications may be made therein which are within the full intended scope of this invention as hereinafter claimed.