US1757388A

US1757388A - Rolled-metal beam

Info

Publication number: US1757388A
Application number: US172860A
Authority: US
Inventors: Norman C Rendleman
Original assignee: Jones and Laughlin Steel Corp
Current assignee: Jones and Laughlin Steel Corp
Priority date: 1927-03-04
Filing date: 1927-03-04
Publication date: 1930-05-06
Anticipated expiration: 1947-05-06

Description

N. C. RENDLEMAN May 6, 1930. 1,757,388

ROLLED METAL BEAM Filed March 4, 1927 JZ l X L ff/ t. E u

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J5 X X Z5 4 l1/wanton K-ffV A20/'mm fmd/eman.,

Patented May 6, 1930 lUNITED STATES PATENT OFFICE NORMAN C. RENDLEMAN, F DORMONT,

PENNSYLVANIA, ASSIGNOR TO JONES &

TION OF PENNSYLVANIA ROLLED-METAL BEAM Application filed March 4, 1927. Serial No. 172,860.

This invention relates to I-beams (including I-beams of the shape known to the trade as H-beams) for use as girders, columns, bridge members, floor joists, rafters, machin- '5'.:ery and vehicle frame members, and structures generally, and aims to increase the strength and reduce the weight thereof by an improved distribution of the metal resulting from the novel cross-sectional shape or con- 101-tour of the beam.

The invention further aims to cheapen the cost of manufacture by shaping the blank and beam in its successive stages of manufacture so as to permit of rolling it on compara- Isl tively small size mills, and to enable a number of sizes to be finished `without reheating the blanks or changing rolls.

Further objects and advantages of the invention will appear in connection with the '201 following description of the illustrative elnbodiments shown in the accompanying drawings, wherein Fig. 1 is a view of the end of a steel I- beam or column, showing its contour with 215i reference to the two principal axes of the shape; and v Fig. 2 is a similar view of a beam having a deeper web and proportionately thicker but narrower flanges, and also showing the ar- Taeg rangement of the rolls for supporting the internal sides of the flanges in the finishing pass for producing the shapes according to one mode of practicing the invention.

The invention contemplates so shaping the flanges 11, 13, at the opposite extremities of the web 12, 14, in the shapes shown in Figs. 1 and 2, as to enable rolling the beam with a minimum of distortion due to unequal cooling of the web and flanges, and with a greater transverse stiffness than is possessed by standard I-beams of the same depth and weight per foot. Both of these objects are attained by sloping the internal faces of the flanges oppositely to the slope of standard I-beains, that is, inwardly away from the web with respect to the principal axis X-X of the beam, thereby increasing the thickness of the flanges at their extremities.

The improved contour results in the center of gravity of each half flange being located farther away from the median lane of the web, located on the axis Y- in Figs. 1 and 2, than in standard I-beams, and hence increases the radius of gyration and resistance to bending of the beam laterally as compared with the standard shape of I-beam having the internal faces of its flanges sloping outwards toward their extremities. This is particularly advantageous for columns and members subjected to compression stresses, but is also beneficial for girders subjected to bending only, because the latter usually fail by buckling ofthe flanges in compression.

Fig. 1 shows diagrammatically the position of the center of gravity 10 of each half flange, and the relationship between the radius of' gyration about the axis X--X, indicated by the arrow rn, and the radius of gyration about the axis Y-Y, indicated by the arrow rw, from which the approximate uniformity of the radius of gyration with respect to said principal axes is apparent. This is desirable in beams loaded principally in compression, as columns, struts and chord members of buildings and bridges, because it stiffens them equally and permits greater heights and longer spans without undue tendency to bend sidewise in any direction.

ln the shape shown in Fig. 1, the flanges 11 at their points of juncture with the web 12 are of about the same thickness as the web, and in the shape shown in Fi 2, the flanges 13 are somewhat thicker than the web 14 at their points of juncture. In both shapes the thickness and width of the flanges are such as to make the area of each fiange adequate to develop the full strength of the web for the use desired.

A convenient method ofproducing my improved beams is illustrated in Fig. 2. The billets or beam blank may be preliminarily formed in the usual manner to present a web and flanges` of considerably heavier shape than that desired for the finished beam, and reduced to approximately the dimensions of 95 the finished shape by rolling it as many times as are found to be necessary in a mill of the universal type, having horizontal rolls and Vertical rolls mounted to rotate with their axes in the same plane. Such mills are well 100 bring its web into a vertical plane and passed between two sets of cylindrical bending and flange straightening rolls acting first on one flange and then on the other, as shown in Sack atent No. 1,013,567, dated January 2, i912, for example. Each bending roll is provided with two oppositely disposed taperedV flange and web supporting rolls l5 which project within the flanges and have flat end faces contacting with the opposite sides of the web, as shown in Fig. 2. These rolls are preferably set with their axes A-B and A-B at a slight angle with the perpendicular to the plane of the web, so as to engage the inner side of the flange for the full width and round the fillets, but their flat ends contact with the web only adjacent to the fillets and gradually diverge from the faces of the web as they leave the fillets.

rlhe cylindrical top and bottom bending rolls may be adjustable toward and from the center axis of the beam to control its depth, and the tapered rolls l5 are independently adjustable toward and from the cooperating bending rolls to determine the thickness of the flanges. i The slight adjustment of these rolls needed to shape the beam to its desired finished contour may be made without interfering with the proper rolling of the beam.

Preferably the thickness of the flanges where they join the web is not greatly in excess of the thickness of the web, and the concentration of a considerable mass of metal at the junction of the web and flanges characteristic of standard I-beams, which results in unequal cooling of the web and flanges during the rolling operation, is thereby avoided. rlhe greater concentration of metal in the louter edges of the flanges where radiation is most rapid tends to maintain uniform temperature in all parts of the beam during the rolling process. This enables the rolling to be continuous at a lower temperature and permits the web to be rolled thinner in proportion to the average thickness of the flanges than has heretofore been considered possible, and has the important advantage that it avoids internal stresses due to unequal rates of cooling, thereby enabling the beam to carry a greater working load.

The contour of the beam may be varied within wide limits, depending upon the use to which it is put. For struts, columna, and

A structural members subjected to lateral bending or transverse bending in more than one direction, the flanges may advantageously be made wider and thicker at their extremities in proportion to the web than for girders and structural members subjected to bending in one direction only. Where wide flanges are objectionable the same strength, both in the principal plane of the beam and at right angles thereto, as that of a standard beam may be secured with a narrower flange by making the edges correspondingly thicker.

lt is evident that beams having the characteristic contour of the invention formed by Y tapering the flanges inwardly insteadv of outwardly have many practical advantages, due to their more uniform properties and greater strength, both in their production and in their use. No claim is made herein for the process of production described, that being expressly reserved for another application for patent.

The invention is not restricted to the shapes and proportions illustrated, as these may be varied to suit the purposes desired, as will be readily apparent to those skilled in the art.

What I claim as my invention and desire to secure by Letters Patent is as follows:

l. A solid completely rolled metal -beam or irl-section having a median web, the flanges being thicker at points remote from the web than at the web, the thickness of the flanges at the web being as great as but not greatly exceeding the thickness of the web at points adjacent to its junction with the flanges.

2. A solid completely rolled metal l-beam or l-l-section having a median web and symmetrical flanges ofvarying thickness no thinner than the web adjacent thereto and thicker at points remote from the web than at the web, the outer faces of the flanges being strlight and perpendicular to the axis of the we Y 3. As a new article of manufacture, a solid completely rolled I-beam of symmetrical cross-sectional shape about its major and minor axes having a median web and opposit-ely disposed flanges at the-edges of the web characterized by the flanges being thicker at their extremities than at the web.

4. As a new article of manufacture, a solid rolled I-beam of symmetrical cross-sectional shape about its major and minor axes having a median web and oppositely disposed flanges at the edges of the web characterized by the flanges being thicker at their extremities than at the web and tapering uniformly towards the web. c c

5. As a new article of manufacture, a solid completely rolled -beam of symmetrical cross-sectional shape about its major and minor axes having amedian web and oppositely disposed flanges at the edges of the web characterized by the flanges being thicker at their extremities than at the web and decreasing to a thickness at the web approximately the vsame as that of the web.

6. As a new article of manufacture, a solid rolled I-beam having a web and oppos-itely disposed inwardly tapering flanges at the extremities of the web of a contour, providing a ratio of flange area to web area not less than and transverse stiffness substantially greater than that of known I-beams as heretofore rolled of the same weight.

7. As a new article of manufacture, a solid rolled I-beam having a web and oppositely disposed inwardly tapering flanges at the eX- tremities of the web providing symmetrically disposed regions of concentration of metal near the extremities of the flanges and stiffening their edges against buckling.

8. As a new article of manufacture, a solid rolled I-beam having a median web and symmetrical flanges at the edges thereof presenting flat outer sides and inner sides sloping inwards away from the web to provide a strong light member as compared with known beams as heretofore rolled.

9. As a new article of manufacture, a solid rolled I-beam having a web and fianges symmetrically disposed with reference to the axis of the web, each of said flanges being of gradually increasing thickness from a point near the juncture with the web toward the ends thereof.

In testimony whereof, I have signed my name to this specification.

NORMAN C. RENDLEMAN.