US1013650A - Solid rolled metal eight-inch i-beam. - Google Patents

Description

H. GREY. SOLID ROLLED METAL EIGHT INCH I-BEAM.

APPLICATION FILED SEBT.14, 190s.

1,013,65Q, Patented Jan 2, 1912.

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HENRY GREY, or NEW YORK, N. Y., AssIGNon 'ro AMERICAN UNIVERSAL MILL comrm, or new YORK, N. Y., A CORPORATION or wnsr VIRGINIA.

Specification of Letters Qatent.

?atented Jan. 2, 1912.

Application filed September 14, 1903, Serial No. 173,109.

To all whom it may concern:

Be it known that I, HENRY GREY, a citizen of the United States of America, residing at.New York city, in the county of New York and State of New York, have invented certain new and useful Improvements in Solid Rolled Metal Eight-Inch I-Beams; and I hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the artto which it pertains to make and use the same. 1

This invention relates to an improved solid rolled eight-inch I-beam.

The general object of this invention is to produce an improved 'solid rolled steel or iron I-beam having a height of eight inches and capable of safely carrying on any span whose length in feet is equal or somewhat exceeds the height of the beam in inches, for a given unit of material, a greater load than has heretofore been carried. In other words, this invention has in view the roduction of a solid rolled metal eight-inch I-beam which shall, by reason of an advantageous distribution of material in its Web and flanges, be able to safely carry, on all spans included within the above-mentioned limitation, a larger load to the unit of weight inthe said beam than has heretofore been carried by any heretofore produced solid rolled I-beam of the same height.

The object of this inventiommore specifically stated, is to produce solid rolled eight-inch Lbeams which are capable of safely carrying, on spans of at least one foot for every inch inheight of the beam, an evenly distributed safe load equal in amount to that carried by any heretofore made solid rolled I-beam of the same height, with ten per cent .less weight of material.

Another object is not only the production of a solid rolled eight-inch Ibeam which shall, by reason of an advantageous distribution of material in its web and flanges, be able tocarry safely, on all spans included Within the above-mentioned limitation, a larger load to the unit of weight in the said beam than can be carried by any heretofore produced solid rolled I-beam of the same height, but which is free from imperfec; tiohs, latent as well as visible, and has a web of considerably less thickness than the thickness of the web of the heretofore made solid rolled I-beams of the same height and to the mean thic less in thickness relative ess of the flanges than the webs of the said beams of the prior state of the art, and has a width which, measured straight across the outer sides of adjacent also considerabl oppositely projecting flanges of the beam, is

considerably greater relative to the mean thickness of the flanges of the beam than the width of any solid rolled eight-inch I- beam of the prior state of the art.

With these objects in view, this invention consists more es ecially in the production of a solid rolled eight-inch I-beam having such width relative to the mean thickness of the flanges, with the mean thickness of each flange and the thickness of the web hearing such proportion. to each other, that the coefficient of. strength in the said beam, per unit of Weight of one pound, for a fiber stress of sixteen thousand (16,000) pounds per square inch, exceeds ten hundred and sixty pounds (1060 lbs.) for every inch of height of the beam.

In the accompanying drawings, Figure 1 is a cross-sectional view of a solid rolled eight-inch I-beam embodying my invention. Fig. 2 is a cross-sectional view of the solid rolled eight-inch standard I-beam of the prior state of the art. Fig. 3 is a cross-sectional view of a rough beam or blank suitable for use in the manufacture of my improved solid rolled eight-inch I- beam illustrated in Fig, 1.

Referring to the drawings, w, represents the web, and f, the flanges of the beam.

M, in Fig. 1, designates a solid rolled I- beam embodying my invention and having a height of eight inches, as already indicated,that is, measurin eight inches (8") between the outer sides oi the flanges formed at one and the same sideof the web of the beam. The beam M has a width of five inches and eighteen hundreths of an inch 5.18"),that is, measures five inches and eighteen hundredths of an inch (5.18") be- -per cent.- The weight of the beam M, per

running foot, is sixteen pounds and twotenths of a pound (16.2 lbs.). The coefficient of strength of the beam M, for a fiber pounds (18 lbs)? per running foot.

stress of sixteen thousand pounds (16,000 lbs.) per square inch, is one hundred and fifty-one thousand, two hundred pounds (151,200 lbs), and the coeflicient of strength for the unit of one pound, in the said beam, is therefore, nine thousand, three hundred and thirty-three pounds (9,333 lbs.) the quotient obtained by dividing 151,200 bs. by the number of pounds (16.2) per running foot in the beam, and the quotient, obtained by dividing the coeflicient of strength for the unit of one pound (9,333 lbs.) by the number of inches that; the beam is high (8) is eleven hundred and sixty-six pounds (1166 lbs.) which is the coefilcient of strength, in the beam M, per unit of one pound, for every inch of the height of the beam, anda load which, when evenly distributed, the said beam can safely carry per ound of a span for which the said beam isgesigned, instead of ten hundred and fifty-fourpounds (1054 lbs.) which is the greatest load which any heretofore made solid rolled beam of the same height can safely carry, per pound of material, on .a corresponding span. N, in Fig. 2, represents a standard solid rolled eight-inch I-beain'of the prior state of the art. The beam N weighs eightle ieln e thickness of eac ange of the beam N is somewhat over fifty-eight hundredths of an inch (.58 at the root of the flange and twenty-seven hundredths of an inch (27 at the longitudinal edge of the flange, so that the said flange has a mean thickness of four hundred and twenty-five thousandths of an inch (.4257). The web of the beam N has a thickness of twenty-seven hundredths of an inch .27). Hence each flange of the beam N as a mean thickness of approximately one and fifty-seven-hundredths (1.57 times the thickness of the web. The coefficient of strength in the beam N, for a fiber stress of sixteen thousand 516,000) pounds, per square inch, is one hunred and fifty-one thousand, seven hundred (151,700) pounds, and obviously the coefiicient of strength for the unit of one pound, in the said beam, is eight thousand, four hundred and twenty-seven (8,427) pounds,

or ten hundred and fifty-four (1054) pounds beam N- has a width of four inches (4") or fifty .per cent. of the height of the beam. That is, the said beam measures four inches (4") straight across the outer sides of adj acent oppositely projecting flanges of the beam. The width of the beam N is obviously less than ten times the mean thickness of the flanges of the beam, and the taper of the inner sides of the. said flanges is sixteen (16) per cent. I

O, in Fig. 3, represents a cross-sectionally I-shapedblank especially suited for use in the production of my improved solid rolled eight-inch I-beam illustrated in Fig. 1. The blank 0 measures in height somewhat over fourteen inches (14) and has a width of,that is, measures straight across the flanges,five inches and seven-tenths of an inch (5.7). The mean thickness of each flange of the blank 0 is three inches and thirty-five hundredths of an inch (3.35") and the thickness of the web of the blank is one inch and eight-tenths of an inch (1.8"), and hence the mean thickness of the said flange is approximately one and eighty-sixhundredths (1.86) times or nearly twice as thick as the web of the blank. It will be observed, therefore, that the mean thickness of each flange of the blankO bears to the thickness of the web of the blank the same or approximately the same ratio which the mean thickness of the said flange, when finished and as it is to exist in the beam M, Fig. 1, to which the said blank is to be reduced, bears to the thickness of the web of the beam.

The improved I-beam, illustrated in Fig. 1, can be readily made by providing and suitably heating the cross-sectionally I- shapedblank shown in Fig. 3 in Whichblank, as already indicated, the thickness of the web and the mean thickness of each flange bear to each other thesame or substantially the same proportion which the mean thickness of the said flange and the thickness of the web are to bear to each other in the I-beam to whichthe said blank is to be reduced, and then rolling the flanges and web simultaneously in a rolling-mill and thereby reducing the mean thickness of each flange and the thickness of the web in the proportion which-the mean thickness of the said flange and the thickness of the web bear to each other in the blank. @This method of reducin the said blank is invaluable to avoid imperfections, latent as well as visible, in any portion of the resulting product.

my improved solid rolled eight-inch I- beam has no more material in its web than actually needed, and obviously considerably less material than the solid rolled I-beam of the same height in the prior state of the art.

In attempting to design an I-beam the result is always a compromise between an ideal that exists in the mind of the theorist and the practical possibility that can be attained in the manufacture of the beam. Solid rolled I-beams made prior to my invention have too much material in close proximity to the neutral axis. The moment of inertia of an I-beam, when the latter is to be used as a joist or girder, is calculated by the well known formula, viz:

1 of [w y-is] In the said formula, I stands for the moment of inertia, with the neutral axis perpendicular to the web at the center; 6, for the width of the beam; d,,for the height of the beam; h, for the distance between the flanges at one and the same side of the web at the longitudinaledges of the said flanges Z, for the distance between the roots of the flanges at one and the same side of the web;

T b t and t stands for the thickness of the web.

From the said moment of inertia a coeflicient for any given fiber stress is calculated for determining the evenly distributed load that the beam will safely carry. The said formula shows the coeflicient equal to 8 X fiber strain X I span in inches X12 and it stands for the distance of center of.

solid rolled eight-inch, I-beam,.have resulted in my inventing such a proportion, in a solid rolled eight-inch I-beam, between the thickness of the weband the mean thickness of the flanges, and between the mean thickness of the flanges and the width of the flanges, as to produce my improved solid rolled eight-inch I-beam, which when used as a girder or joist, is, with ten per cent. less material in 1t, equal in loadcarrying capacit to the solid rolled eightinch I-beam o the prior state of the art.

What I claim-is:-

1. As a new article of manufacture, a-

solid rolled I-beam eight inches or over in height and the ratio of the width of the flanges to the thickness of the web is not less than'twenty-two.

2. As a new article of manufacture, a solid rolled I-beam, the height of which is eight inches or over, and the ratio of the width of the flanges to the thickness of the web is not. less .than twent two, the said width of flanges being su 'stantially 5.18 inches and the said thickness of web being substantially .18 of an inch.

'3. As a new article of manufacture, a solid rolled I-beam the width of the flanges of which is not less than fifteen (15) times greater than the mean thickness of said flanges.

In testimony whereof, I sign the foregoing specification, in the presence of two witnesses.

HENRY GREY. Witnesses:

C. H. Donna, VICTOR G. Luzon.

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