US1804132A - Construction unit - Google Patents

Description

May 5, 1931.

E. H. TASHJIAN CONSTRUCTION UNIT Filed Sept. 17. 1928 Patented May 5, 1931 PATENTY OFFICE EDWARD T1'. TASHJIAN, OF NEW YORK, N. Y.

CONSTRUCTON UNIT' Application filed September 17, 1928. Serial No. 306,365'.

The present invention relates to an improvement in building construction and more particularly to that type of floor em` ploying a plurality of skeleton joists each 5 vconsisting essentially of a compression member, a tension member, and a web of zig-zag shape interposed between them. Upon these joists With their ends supported by Walls or girder's is placed a sheet of expanded metal or the like upon which concrete is poured to form a floor slab. Floors constructed in this manner comprise in effect a floor slab substantially separate from the underlying system of supporting joists. l5 One object of my invention has been to provide a construction in which a material portion of each joist is imbedded or anchored in the concrete floor slab so that they are thus securely and structurally combined to form a composite j oist in Which the slab becomes longitudinally the compression member of said joist. In its broadest aspect, therefore a device according to my invention comprises a tension or loWer mem- "ber, a Web preferably of zig-zag shape, an upper member of suitable Vcross sectional shape Which acts temporarily as a compression member and retains the mesh or other suitable slab support during erection and v 'While the concrete is still plastic, and a slab engaging member formed either by a looplike extension of the Web orby any other suitable anchoring member projecting above the upper member and having portions adapted to extend into and engage a mass of concrete forming a floor slab, thus causing the slab to function as a compression member of said joist. l A preferred embodiment of my invention @L -is illustrated in the drawings accompanying this specification and in which Figure l is a View partly insection illustrating a single web joist with portions of the Web imbedded in a concrete mass;

' Figure 2, an enlarged detail partly in section of a portion of a double Web joist;

Figure 3, an enlarged detail partly in section on the line 33 of Figure 2;

Figure 4, a fragmentary vieW illustrating an arrangement of a plurality of single Web CII kother suitable means.

j oists and reinforcing rods associated therewith;

Figure 5, a View partly in section showing a form of joist in which the anchoring extensions are integral with or secured to the upper member of the joist; and,

Figure 6, a view partly in section showing a further modification in which the anchoring extensions engage or are secured to the upper member of the joist.

Referring to Figure l of the drawings, one form of joist employing my invention comprises a lower or tension member l of any desired cross sectional shape, an upper member 2 consisting of one or more longitudinally extending irons of angular or other suitable shape, and a. single web 3 Which may be a rod of round or other suitable contour and bent into a Zig-zag shape, said tension member l and said upper member 2 being secured to said web 3 as by Welding or The bent portions of Web 3 form loop-like extensions 4 which project beyond the outer or upper surface of the upper member 2 to such extent that, when the extension is imbedded in concrete, there Will be a `suiiicient mass or body of concrete Within the bight of said extension, loop or other shape to present effective resistance to shear.

As indicated more clearly in Figures 2 and 3, the Web may include a plurality of members as 3 and 8 Which are providedwith loops or extensions projecting into a mass of concrete or conglomerate 5 resting upon a flexible metallic member `6 of expanded metal or the like supported upon the upper surface or edge of the compression or upper member 2. The extensions 4 pass through said vexpanded metal to retain the same in stretched relation across the joists. Reinforcing rods as 7 are threaded through the bights of the loops or extensions 4 and lie transversely across the upper member 2.

As indicated in Figure 4, the skeleton joistsV may be assembled in such a manner that the loops il of one joist, as A, Will be in staggered relation with respect to similar loops i of an adjacent joist B. With such an arrangement, one reinforcing rod' 7 is linked with loops l in every other joist A, while an adjacent rod 7 is linked with loops 4 in every other j oist A, While an ad jacent rod 7 is linked With the loops of every other joist B.

In Figure 5, I have shown a modiiication in which the web 3 is interposed substantially between the lower member l and the upper member 2, and an anchoring extension 9 of any suitable shape is secured to or forms part of the upper member As shown in Figure 6 the anchoring member is a separatereadily attachable clip as l0 having any desired arrangement of convolutions or loops, it being contemplated that the anchoring members Whether secured ton or attachable to the upper member 2 may comprise a Wide variety of shapes to meet diii'erent conditions or circumstances of use.

important advantages oi my invention, therefore, include among others a saving ot from 2 to 3 inches in the over-all thickness of the iloor and substantial economy oi steel, the latter being eilectcd in. part by a reduction of section in the tension member due to an increase of the moment arm one end of Which is located in the slab, and in part by the entire or partial elimination et steel directly in compression when the concrete has set. Furthermore, the use oi' my invention produces greater rigidity and firm ness of construction as compared with the independent joist system iirst above referred to and 'frequently ifound detective because oi' its iiexibility and its tendency to deiiect and vibrate under load and impact sufficiently in many cases to result in cracking of the overlying concrete slab.

I claim as my invention:

l. A construction unit comprising an upper member, a tension member, and a Vweb consisting of a pair of rods bent to Zig-Zag shape each secured to said members and each having anchoring extensions beyond the outer edge of said upper member, the extensions oi one rod alternating With successive extensions of the other rod along the length of Ythe unit.

2. Building construction comprising a skeleton joist having an upper' member, a Zig-Zag Web secured thereto and anchoring extensions projecting above said member, flexible metallic reinforcing means supported above said upper member, and` a body oi" concrete on said reinforcing means and enclosing portions of said anchoring extensions.

Building construction comprising a skeleton joist having anrupper member, a Zig-aeg web and anchoring extensions projecting above said member, flexible metallic reinforcing means supported above said upper member, a tie member extending through the Ybight of said anchoring extension, and a body oit concrete disposed on said reinforcing means and enclosing portions oi' said anchoring extensions and of said tiermember. Y

4. Building construction comprising a plurality of skeleton joists each provided With an upper member, a Zig-zag web, and anchoring extensions projecting above said upper member, said joists being so disposed that the anchoring extensions of one will be in stepped relation to the anchoring extensions ott an adjacent joist, tie members extending transversely across said joists and through the bights oi' said anchoring extensions, and a body of concrete positioned above said j'oists to enclose portions of said anchoring extensions and of said tie members.

5. A skeleton joist comprising an upper member, a tension member having end portions extending across spaced portions of said upper member to form end anchoring extensions, a web secured to said members, and interniediate anchoring extensions positioned between said end anchoring exten- Sliblls.

ln testimony whereof, l have signed my name to this specification this lllth day of ISeptember, 1928.

EEWJVARD H. TASHJIAN.

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