US542206A

US542206A - Concrete-iron construction

Info

Publication number: US542206A
Authority: US
Publication date: 1895-07-02
Anticipated expiration: 1912-07-02

Description

' (No Model.)

E. L. RANSOME. Y GONORETE IRON CONSTRUCTION.

No'.542,206. 4 Patented July Z, 1895.

v #im v l STATES reina.

CONCRETE-IRON CONSTRUCTION.

SPECIFICATION forming part of Letters Patent No. 542,206, dated July 2, 1895.

Application filed October 10. 1894:. Serial No. 525,531. (No model.)

To all whom it may concern: 1

Be it known that I, ERNEST LESLIE RAN- SOME, a citizen of the United States, residing at Chicago, county of Cook, and State of Illinois, have invented an Improvement in Concrete-Iron Construction; and I hereby declare the following to be aclear and exact description thereof.

My invention relates 4to that class of construction in which the strength of the structure is largely increased by the embedment of iron bars into the body of the material, and it is an improvement upon the construction for which Letters Patent No. 305,226, of September 16, 1884,' and No. 516,113, of March 6, 189i, were granted me. 4By those inventions a continuous bond was created between the cement and the iron by means of long spiral threads formed upon the bar by twisting, square or polygonal iron being used.

My present invention consists in an alteration to the form of such bars, whereby the longitudinal bond created by the threads is en# larged and thel transverse bond greatly increased.

According to this invention one or more of the sides or planes between the spiral threads or ridges are made concave or recessed, instead of being dat, as heretofore.

The accompanying drawings illustrate this invention.

Figures 1, 2, and 3 represent various crosssections of my improved bar. Figs. 4 and 5 are end views of the ordinary twisted and my improved bars respectively, embedded in concrete beams D D in the usual manner, each having one-eighth of a circumferential twist in its length. The arrows indicate the direction of the strain upon the beam when it is loaded.

It is apparent that concaving the sides of the bar intensities the spiral'threads, fins, or webs created on the bar, and that in making these more prominent the bond. between the concrete and the iron is increased. This is an advantage, but the chief advantage of this invention is in the greater cross or transverse bond which it makes.l

It will be observed that in Fig. 4, which represents the ordinary twisted bar, the tendency of the concrete to split or separate, so far as thev bar influences it, is only hindered by the adhesion and slight irregularities of the surface of the iron.

Take, for example, the tendency to split along the line A A. But for the adhesion of the concrete to the iron and the small irregularities of the parallel sides B B there is nothing relative to the bar to prevent the concrete from breaking along the line A A following the direction ofthe thread. By making the sides of the bar concave, as shown in Figs. 1, 2, 3, and 5, this tendency to split along the line A A is not only hindered by the previously-mentioned adhesion and irregularities but it is resisted by the positive obstruction of the outward curve of sides B B', as shown in Fig. 5, to such an extent that before its resistance can be overcome the concrete must shear apart along lines C C. The like resistance will in like manner be found wherever the line of strain may occur, and in narrow beams of concrete-iron'construction such resistance is of great importance and benefit. It is also of great value where the iron is used for resisting compression, for the more closely and perfectly the concrete and iron can be bonded together in such cases the better will they act infunison and the greater will be their poweys of resistance.

For the purpose of this invention I regard stone, brick, and other masonry, glass, or like substance as the equivalent of concrete, and other metals having the requisite characteristics as the equivalent of iron.

yThe recess may be obtained in the commercial irons in the star-shape bars, as shown.

in Fig. 2, or it may be rolled specially as de- Sired.

When used for withstanding compression, the bars may be cast instead of being wroughtiron.

What I claim as new, and desire to secure ERNEST LESLIE RANSOME.

Witnesses:

LILLIAN GRAY, S. FERD. HowE.