US732484A - Fireproof floor and method of constructing same. - Google Patents

Description

N0. 732,4 34- PATENTED JUNE SO, 1903.

PIRBPROOF FLOOR AND METHOD OF CONSTRUGTING SAME.

APPLICATION FILED SEPT. 30, 1902.

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Q v I Alli n I w No. 732,484. PATBNTED JUNE 30, 1903.

W. N. WIGHT. FIREPROOF FLOOR AND METHOD OF GOHS TRUO-TING SAME.

APPLICATION IILBD SEPT. 3.0, 1902.

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. Patented June 30, 1903 PATENT OFFICE.

WILLIAM N. WIGHT, OF NEW YORK, N. Y.

SPECIFICATION forming part of Letters Patent No. 732,484, dated jllil so, 1 903. Application filed September 30, 1902. Serial No. 125,361. (No model.)

- citizen of-the United States, residing in the borough of Manhattan, city, county, and State of New York, have invented a certain new and useful Improved Fireproof Floor and Method of Constructing the Same, of which the following is a specification.

My invention aims to provide certain improvements relating to fireproof floors whereby to facilitate the construction of floors of great load-sustaining power with a minimum depth and weight, so as to economize both space and material in their construction.

Various other features of advantage are specified in detail hereinafter.

Referring to the accompanying drawings, illustrating embodiments of the invention, Figures 1 and 2 are transverse sections across the beams, illustrating the process of construction. Fig. 3 is a section at right angles to Fig. 1, showing the construction of the lower portion of myimproved floor. Figs. 4, 5, and 6 are sections of details. Figs. 7, 8, 9, and 10 are sections similar to Fig. 2, illustrating other forms of floor embodying the invention. 7

My invention is directed to improvements in floors of the type composed of concrete molded with a metallic reinforce embedded therein and is shown in connection with the steel I-beams usually employed.

A feature of the invention by which concrete is economized and the structure lightened without seriously reducing its supporting power is in the formation between the supportingbeams of a concrete structure molded in place between the beams so as to fit accurately and bear uniformly at all points and comprising upper and lower plates of concrete spaced apart from each other'at their intermediate portions, either with a filling of light material between them or with only a hollow air-space between them, and preferably united to each other at their'ends. The lower plate may be provided with an embedded metal reinforce, so as to increase its tensile strength, and this reinforce is preferably carried by the beams, extending over the tops thereof, so as to securely support the lower plate. Preferably also the upper plate is provided with a metal reinforce. In order to give additional support to the intermediate portion of the lower plate, it is preferably connected by any suitable tie with the upper plate,this construction beingespeciallyadapted for long spans or thin plates. The process by which I make possible the construction of such a floor comprises the use of a temporary center of loose granular material, upon which the upper plate may be molded, and which may then remain in place as a dead load, or which may be removed through a suitable opening formed in one of the plates for the purpose, and preferably, but'not necessarily, formed in the plate in the original molding of the same.

Referring now to the drawings, A represents supporting I-beams, which are preferably attached at their ends to deeper girders B of the same shape, as indicated at the right in Fig. 8.

C is an ordinary flat center, upon which the concrete is supported while hardening. The concrete structure between the beams comprises an upper plate D, Fig. 2, and a lower plate E, the former of which is arched, so as to be separated a considerable distance from the latter at its intermediate portion and so that its ends are united with the ends of the lower plate E or supported directly thereon. The lower plate E is provided with a metal reinforce F,which is preferably a wire-netting of the type illustrated in my application for Patent, Serial No. 114,868, filed July 9,1902, and which may be briefly described as composed of straight wires in one direction, cross-wires spacing said straight wires and bent around the same at the crossing-points, and bindingwires binding together the straight wires and the cross-wires at the crossing-points. The wires which extend transversely between the beams are the straight ones, as shown in Figs. 2 and 3, so as to transmit the loads to the beams without any yielding of such wires. The reinforce F is preferably carried by the beams, being shown as extending up and over the tops of the beams and into the adjacent bay. In fact, it preferably extends from wall to wall of the building continuously. The reinforce gives to the substantially flat plate E a desired increase of tensile strength. It extends, at least for the greater part of its length, through the lower portion of the plate E, since it is in the lower portion that the tensile stresses come. The upper plate D also may be provided with a metal reinforce G, constructed of netting similarly to the reinforce F and embedded in the plate D, preferably in the lower portion thereof. The reinforce G at its ends engages the reinforce F of the lower plate, so that the strain which is transmitted to the ends of the upper plate D and its reinforce are transmitted thence to the ends of the reinforce F, thus straining the latter in an endwise direction and giving it increased resistance against transverse stresses at the central portion of the lower plate E. The central portion of the lower plate E may, especially in the case of long spans, be additionally supported by ties H, embedded at their upper ends in the upper plate D. In the usual construction in which metal reinforces F and-G are used the ties H consist, shown, of wires looped over these metal reinforces at suitable points.

The process of constructing my improved fioor is illustrated in Figs. 1 to 6. The center 0 or any other suitable center and the reinforceF being arranged in position, concrete is spread on the center to a desired depth extending from the web of one I-beani to the web of the opposite one, so as to rest on the lower flanges of the beams. When this lower plate E has set sufiiciently, a second center J, of loose material-such as cinders, cokebreeze, sand, gravel, or sawdust or shavings treated to render them non-infiammable-is molded to a desired arch form. The reinforce G for the upper plate is then laid in position, preferably with its ends engaging the angle of the reinforce F of the lower plate, and the upper plate D is then molded directly on the center J, with its ends resting witha broad bearing on the ends of the lower plate E. It is understood that the ties II are connected to the lower reinforce F and held upright during the formation of the lower plate and the center of loose material and are attached to the reinforce G before the upper plate is molded. The haunches of the arch are preferably filled in with cinders or similar loose material K. The flooring is applied directly to the top of this structure and the plaster or other finishing of the ceiling may be applied directly to the lower face of the plate E. By reason of the ties H the plate E isadapted to support a very heavy ceiling, even though itself made quite thin. The entire structure, though extending neither above nor below the I-beams, is of great strength, because of its total depth at the center,where the greatest transverse strain comes. The arched upper plate transmits to the I-beam all the strains which come upon the floor, while the lower plate transmits the strains which are due to the weight of the ceiling, the lower plate being itself to some extent supported and strengthened by the upper plate by reason of the ties H and the engagement of the reinforce G with the reinforce F at the ends of the latter. The center J and the filling K are of the lightest practicable material, the former, in fact, sustaining no strain whatever, but being only of temporary usefulness during the construction of the upper plate I.) and being but a slight addition to the dead load which the beams have to carry.

Where the maximum economy of steel, and therefore a reduction of the dead load to a minimum, is necessary, I may even eliminate the weight of the material Jand leave ahollow air-space between the upper and lower plates D and E. The method of doing this is to leave in one of the plates D or E when molding it a suitable opening for the subsequent removal of the loose material after it has served its purpose in supporting the upper plate until the latter sets and hardens. This process and the resulting hollow structure are illustrated in Figs. 3 to 10, inclusive. Acenter 0 being extended from one to the other of the girders B and below the I-beams A, collapsible fillingpieces-such, forexainple, as L-are supported between two I-beams, the filling-pieces L being spaced apart from each other a considerable distance, as shown. With these filling-pieces in place the reinforce F is set in place and the lower plate E molded to the desired depth in the spaces between the filling-pieces L. The destructible center J, of loose material, is then molded, as in the previous case, to the desired form of the under face of the u per plate, the reinforce G of the upper plate is set in place, the ties H are attached to the reinforce, and the upper plate D is molded to the desired depth upon the center of loose material. \Vhen the concrete has set and hardened sufliciently, the center 0 being'removed the filling-pieces are taken out, and the loose material J is drawn out through the openings M with any suitable tool, similar to a small rake or hoe. An advantage of forming the aperture M in the lower plate in connection with the destructible center of cinders or the like lies in the fact that when the interior center is destroyed the material has only to be scraped to the opening, when it will fall out easily. A further advantage is that it will fall directly where it is desired to use it-that is to say, upon the top and haunches of the arch of the next floor belowthus saving a rather expensive handling of the material. The center being of loose granular material can be removed through a very small opening, and its destruction is more easily accomplished and requires less care than the taking apart of any center which can be made of ordinary-structural material, such as wood or iron. The wood or iron is not destroyed, but is so expensive comparatively that it must be kept for further use. Hence a certain amount of care and delay is involved in removing it.

After the temporary center of loose material has been removed it is desirable to close v the opening M before finishing off the ceiling.

For this purpose I may use a block N, Fig. 4,

whose depth is less than the width of the opening, so that'it can be turned endwise and pushed up into the hollow space and then turned horizontally and dropped into the opening, the latter being upwardly flared, as shown, to prevent the block falling out. The block N may be of concrete, tile, or any other suitable material. The block and the wall of the opening may be gradually flared, as in Fig. 4, or they may be stepped, as in Fig. 5, at M and N. The construct-ion which I prefer, however, provides an opening M Fig. 6, with substantially vertical edges and a block N fitting in the opening, but tapered off toward its face to leave a key-space O for engagement of the plaster. The block may be held in place by means of rods P and Q, the latter being preferably of the well-known Z shape in plan, extending across the edges of the plate and of the block on opposite sides of the joint and connected together by means of wire ties- R.

The exact shape of the concrete plates D and E and the exact arrangement of the embedded reinforces described are not essential to the invention, but may be varied in a great many ways which will present themselves to constructors. Certain variations are'shown in Figs. 7 to 10, the hollow construction being illustrated in each case, although the features shown are equally applicable to a construction in which the center of loose material is allowed to remain in place. According to Fig. 7 the reinforce F for the lower plate and the reinforce G for the upper plate are formed into a continuous cylinder of wirenetting, following substantially the contour of the two plates. This union of the two reinforces increases the useful tendency of the upper plate to stretch taut the reinforce of the lower plate, and thus increase its resistance against transverse stresses. It is possible also with this construction to extend the lower reinforce F over the lower flange of the I-beam almost to the very end of the lower plate E, and thus strengthen the concrete structure against the shearing stresses, which are a maximum at the edge of the lower flange of the I-beam. The upper face of the upper plate D is curved inthis case and its haunches filled with loose material K, as in the previously-described constructions.

Fig. 8 illustrates a construction similar to Fig. 7 in all respects, except that the upper reinforce G2 is extended only through the central portion of the plate D, so as to form little more than a support for the ties H and to give a slight additional tensile strength to the under face of the plate. The reinforce Gr may, in fact, be entirely abolished, since the plate D being of arched shape stays always in compression under ordinary circumstances. The ends of the reinforce F are turned up into the upper plate, as shown,to tie the two plates together.

Instead of forming the upper plate as a true arch it may be formed as a flat arch D,'Figs.

9 and 10, connected by substantially vertical portions S at its ends with the lower plate E. The molding of this form of upper plate can be accomplished in the same manner as the other forms described. The vertical portions S, of concrete, molded to fill the space between the flanges of the I-beams gives to the beams themselves a very desirable increase of stifiness and strength, while it at the same time transmits the stresses on the upper plate to the lower flange of the I-beam, as in the previously-described cases. With the fiat-arch construction the reinforce of the lower plate may be extended continuously over successive beams, as shown at F, Figs. 1 and 2, or may be formed in one with a reinforce embedded in the upper plate, as in Fig. 7, or may be a separate section extending only through the individual plate E in the manner made clear in Fig. 8, the upper reinforce G being modified accordingly, or the upper reinforce may be in the form of a sheet of netting G Fig. 10, passing continuously over successive I-beams, while the lower reinforce F is an isolated section extending only from end to end of a single lower plate E. With all these constructions one or more ties H may be used, permitting the construction 0 a very thin lower plate E.

The tying of the two plates together at their ends by the cement, and especially by the ends of the reinforce F or F where they extend into or through the upper plate, as indicated in Figs. 1 to 9, unites the entire concrete structure into practically an arched truss, of which the two plates form the upper and lower chords, respectively. Longitudinal strains on the upper compression member may be taken up entirely by the lower tension member. For this reason a skewback is not necessary to support the structure, since no horizontal strains are transmitted to the supports; but any column or pier may be used which will carry the vertical loads imposed. By extending the reinforce of the lower plate not only into the upper plate, but through the same and over the beamsas, for example, in Figs. 2 and 9the building of the structure is much simplified. The truss effect is assisted by the intermediate tie H joining the upper and lower plates.

Though I have described with great particularity of detail a floor anda process of constructing the same in accordance with my invention, yet it is not to be understood that the invention is limited to the floor and process disclosed. Various modifications thereof are possible to those skilled in the art without departure from the invention.

What I claim is 1. In a floor, the combination of supportingbeams and a concrete structure molded in place between said beams comprising upper and lower plates of concrete spaced apart from each other at their intermediate portions and united at their ends, said lower plate being provided with a wire-netting embedded therein and increasing its tensile strength, said-netting being embedded in and surrounded by the end portion of said upper plate and extending continuously over and between a number of said beams.

2. In a floor, the combination of supportingbeams and a concrete structure molded in place between said beams comprising upper and lower plates of concrete united at their ends and spaced apart from each other at theirintermediate portions, each of said plates being provided with a metal reinforce embedded therein, the reinforce of the lower plate extending continuously over and between a number of said beams.

3. In a floor, the combination of supportingbeams and a concrete structure molded in place between said beams comprising upper and lower plates of concrete with embedded wire-nettings, said plates and nettings being spaced apart from each other at their intermediate portions, the reinforce of the lower plate extending continuously over and between a number of said beams.

4. In a floor, the combination of supportingbeams and a concrete structure molded in place between said beams comprising upper and lower plates of concrete with embedded wire-nettings, said plates and nettings being spaced apart from each other at their intermediate portions, and a tie attached to the intermediate portions of said nettings to connect them to each other.

5. In a floor, the combination ofsupportingbeams, a concrete plate between said beams and provided with an opening, and a block (i. Inafioor, the combination ofsupporting- I beams, a concrete plate between said beams and provided with an opening, a block closing said opening, rods extending across the edges of said plate and of said block on 0pposite sides of the joint, and a tie connecting said rods and holding said block in place.

7. In a door, a structure'comprising upper and lower plates of concrete spaced apart from each other at their intermediate portions and united at their ends, and a metal reinforce embedded in said lower plate and at least in part in said upper plate to unite said plates into practically a self-contained truss without horizontal strains on its supports.

8. In a floor, a structure comprising upper and lower plates of concrete spaced apart from each other at their intermediate portions and united at their ends, a metal reinforce embedded in said .lower plate and at least in part in said upper plate, and a tie connecting the intermediate portions of said plates to each other, whereby the whole forms practicallya self-contained truss without horizontal strains on its supports.

9. The process of molding in place between beams a concrete structure comprising upper and lower plates spaced apart from each other with a hollow air-space between them,which consists in molding the lower plate in place on any suitable center, molding on said lower plate a destructible center of loose granular material, molding the upper plate on said center of loose material, and then destroying said center and withdrawing said loose material through a suitable opening formed in one of said plates for the purpose.

In witness whereof I have hereunto signed my namein the presence of two subscribing witnesses.

WILLIAM N. WIGHT.

Witnesses:

DOMINGO A. USINA, FRED WHITE.

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