US633285A - Fireproof-floor construction. - Google Patents

Description

Patented Sept. I9, |899.

A. L. JOHNSON.

FIBEPBOOF FLOOR CONSTRUCTION.

(Application led Nov. 10, 1898.)

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UNITED STATES PATENT OFFICEC ALBERT L. JOHNSON, OF ST. LOUIS, MISSOURI, ASSIGNOR OF ONEHALF TO D. E. GARRISON, SR., OF SAME PLACE.

FlREPROOF-FLOOR CONSTRUCTION.

SPECIFICATION forming part of Letters Patent No. 633,285, dated September 19, 1899.

Application tiled November l0, 1898. Serial No. 696,067. (No model.)

To all whom, it may concern:

Be itknown that I, ALBERT L. JOHNSON, a citizen of the United States, and a residentof the city of St. Louis and State of Missouri,

have invented a new and useful Improvement in Fireproof-Floor Construction, of which the following is a specification.

My invention relates to reproof door and ceiling construction, and has for its principal ro objects to economize labor and material, to reduce weight, and to increase the strength and durability of the structure.

My invention consists principally in transversely-corrugated metallic bars ofsubstani5 tially uniform vthickness throughout their length embedded in the lower portion of concrete slabs or in ribs on the under side thereof. It also consists in a floor and ceiling construction wherein ribs of concrete extend from 2o I-beam to I-beam and have embedded therein metallic rods from which ceiling-hangers are suspended, as hereinafter claimed.

It also consists in the parts and in the combinations of parts described and claimed 2 5 herein.

In the accompanying drawings, which form part of this specification and wherein like symbols refer to like parts wherever they occur, Figure 1 is a perspective view of my floor 3o system.

Fig. 3 is a longitudinal section thereof. Fig. et is la cross-section similar to Fig. 2 except that the main oor layer has a sheet of expanded-metal embedded therein. Figs. 5 and 3 5 6 are enlarged details of the ribbed bar and,

hangers embedded in the concrete ribs.

The present system of ireproof-floor construction consists of haunehes of concret-e 1, resting on the lower flanges of adjacent I- 4o beams 2, incorporated into the building stru eture, a seriesof concrete ribs 3, extending from I-beam to I-beam, and a main door sheet or layer4 of concrete on said ribs and haunches and covering all the space between the I- beams, all incorporated as one solid mass. The lower portion of the strengthening-ribs Sis thus submitted to tensile stress, and as concrete has slight tensile strength a transversely ribbed or corrugated bar or rod 5 of 5o steel-or other suitable metal of great tensile strength is embedded in such lower portion. Although the bond between concrete and metal is originally strong, such bond becomes strength.

Fig. 2 is a4 cross-section thereof.-

broken or weakened in the course of time by the ordinary use and Wear of the floor. For this reason transverse indentations or corrugations are formed in the bar, sothat, re`' gardless of the bond, the bar is so incorporated into the rib as to utilize its full tensile The best arrangement of the in- 6o dentations or corrugations is in planes at right angles to the axis of the bar; but considerable variation in their direction is permissible. Theoretically such-variation is a function of the coeiiicient of friction between the concrete and metal, and the limit of variation in any case is capable of computation as such; but under ordinary circumstances such variations should not exceed fifteen degrees from the perpendicular plane above 7o defined. When the indentations or corrugations are inclined to the axis of the bar, their rid ges act as wedges tending to split the concrete and in the case of considerable variation from the plane above de'ned are very 75 liable to destroy the concrete strengtheningribs.

The next main feature of my invention after the corrugated bars is a loop 6 of pliable wire suspended astraddle such bars and 8o incorporated with them in the concrete ribs, but with its ends projecting below the ooncrete. These ends are intended to extend through interstices in the sheets of expanded metal or other open-work metallic lathing andv to be twisted together on the under side of the lathing to hold said lathing firmly up against the vribs as a foundation for the ceiling-plaster. A'ny other suitable form of hanger may be suspended from the 9o rod in lieu of the wire loop; but Iconsider such loop the most economical.

In operation my invention is carried out as follows: A centering or false work of the kind used for concrete ilooring is mounted on the I-beams in any suitable way. Then a thin layer of concrete is laid in each ribcentering and a ribbed or corrugated bar of a length approximately equal to the distance between the webs of the I-beams is laid thereroo on withoutbeing fastened. 'Wire loops are placed astraddle the bar ats uitable intervals, with their ends projecting through the centering, and then the concrete is filled in as in the ordinary concrete-flooring systems. Then the ribs are spaced farther apart than usual and when the floor is required to be specially strong, expanded metal, wire-cloth, or other similar material may be embedded in the lower portion of the main flooring layer to assist in carrying the load between the ribs.

After the concrete has hardened, the centering or false work is removed and the ceilinglathing is fastened in place merely by passing it over the projecting ends of the wire loops and twisting such ends together. The ceiling is thus held firmly up against the ribs.

There the ceiling is not required to be plastered, the wire hangers may be omitted. So, also, a mere wire embedded in the concrete will serve to suspend the ceiling hangers from, but will not materially strengthen the ribs.

The sectional shape of the bar is practically immaterial in use and will therefore depend largely upon the process of its manufacture and economical considerations. The ends of the bar, as Well as its middle portion, should be large enough to aord a firm bond with thc cement, and for this and other considerations of economy the bar should be of substantially uniform thickness throughout its length. The sectional form of the indentations or corrugations also has a very wide range of Variation and is determined very largely by the economy of manufacture. The proper sectional shape of the indentations is such that when the bar is embedded in a cube of concrete of the thickness of the strengthening-ribs and tested to destruction the bar will be pulled out without splitting the lconcrete. For practical and economical reasons I prefer to use a bar of rectangular section, having in all four of its sides fiutes or scallops of semicircular section and arranged in planes perpendicular to the axis of the bar, as shown in Fig. 6.

The particular advantages of my fiooring, in addition to the saving in labor and material, are that it increases the rigidity of the structure and increases the durability thereof. As the ceiling-hangers are incorporated in the concrete, they are firmly secured without injury to the ribs and are in proper position to hold the ceiling firmly against the ribs. The ceiling is thus especially rigid and free from vibration and is very inexpensive.

What I claim isl. In a concrete-and-metal construction, a slab of concrete having bars of metal embedded in the lower portion thereof, each of said bars being of substantially uniform thickness throughout its length and having corrugations arranged in planes substantially perpendicular to the axis of the bar, substantially as described.

2. In a concrete-and-metal construction, a main slab of concrete having ribs of concrete on its under side, and a metal bar embedded in the lower portion of each rib, said bar being of substantially uniform thickness throughout its length and having corrugations arranged in planes substantially perpendicular to the axis of the bar, substan-- tially as described. l

23. In a concrcte-and-metal construction, a main slab of concrete having expanded metal or other open-Work metal in its lower portion, concrete ribs on its under side and bars of lnetal embedded in the lower portion of said ribs, said bars being of substantially uniform thickness throughout their length and having corrugations arranged in planes substantially perpendicular to the axis thereof, substantially as described.

4. A concrete flooring comprising transversely corrugated bars embedded in the lower portion of strengthening-ribs formed on the under side of the main slab, said bars being of substantially uniform thickness throughout their length substantially as described.

5. A iireproof flooring comprising I-beams, a layer of concrete extending from I-beam to I-beam, concrete ribs on the under side ol' said layer of concrete and arranged transversely to said I-beams, and transversely-corrugated metal bars being of substantially uniform thickness throughout their length and embedded in the lower portion of said ribs, substantially as described.

6. A fireproof iioor consisting of I-beams, concrete haunches resting on the ianges thereof, concrete ribs extending from I-beam to I-beam on the lower side of the main floorslab and having transversely-corru gated bars of substantially uniform thickness throughout their length embedded in the lower porn tion thereof, and a main floor-slab of concrete resting on said ribs and haunches and having sheets of expanded metal or its equivalent embedded in the lower portion of said slab, substantially as described.

7 A iireproof flooring and ceiling construction comprising a main iooring layer of concrete having strengthening-ribs on its under side, transversely-corrugated bars of substantially uniform thickness throughout their length embedded in said ribs, and ceilinghangers suspended from said bars, substantially as described.

8. A lireproof ioor and ceiling construction comprising a flooring-slab of concrete extending from I-beam to I-beam, horizontal strengthening-ribs on the underside thereof, unfastened rods embedded in said ribs, ceiling-hangers suspended from said rods and metallic lathing held up against said ribs by said hangers, substantially as described.

9. A :tireproof ioor and ceiling construction comprising a main flooring-slab of concrete having horizontal ribs on its underside and unfastened rods embedded in said concrete, and pliable wire loops straddling said rods in the ribs and projecting below said ribs, substantially as and for the purpose set fort-h.

A. L. JOHNSON.

Witnesses:

JAMES A. CARR, j D. E. GARRIsoN.

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