US1933430A - Structural shape - Google Patents

Description

Oct. 31, 1933. R. J; HARRY STRUCTURAL SHAPE Filed May 3, 1930 lwezor.' 5055er J HEEY,

Patented Oct. 31, 1933 UNITED s'rli'rgsK PAT-ENT OFFICE This invention relates to structural shapes and, While not limited thereto, relates more particularly to structural shapes of the larger' sizes and has for one of its objects the provision of beams varying in cross-section throughout their length l so as to provide maXimum'vvcross-section Where the stress is greatest and vminimum cross-section Where the stress is least.

Another object is to provide a beam structure which will permit the use of the lightest beam for a given load, and to increase the useful load which the beam will support for the same maximum section modulus.

Heretofore beams have generally had a uniform cross-section throughout their entire length, whereas the load supportedI produces stresses which vary throughout the length of the beam. Uniform section beams are therefore 4subject to a y marked disadvantage as much excess weight must be used on account of the same section being employed lwhere the bending moment is maximum and minimum and also where the. shear is maximum and minimum.

In the drawing: y

Figure l is a side elevation of a beam constructed in accordance with this invention.

Figure 2 is a longitudinal section taken on the line II,II of Figure 1. v

Figure 3 is an end elevation.

Referring more particularly to the drawing, the letter A designates the web portion of the beam and the letter B designates the flange por--l tions.

The web A is composed of a relatively thin center section 2 and successively thicker end sections 3 and 4, all of which sections are welded together end-to-end to form a continuous structure.

The flange portions B are each composed of three rolled metal plates 5, 6'and 7 arranged one on top of the other and Welded together along their longitudinal and end edges.

The plates 5k are of the same length as the center section 2 of the Web and are welded direct- 45- ly thereto by welds 8 along the longitudinal edges vof the web-plate. lIfhe web sections 3 are of a greater height than the section' 2, the difference y being equal to the thickness of the flange plates 5,- so that the edge faces of the web-plates or sections 3 are flush with the outer faces of the flange plates 5.- The second flange lplates 6 are of a length equal to the combined length of the webplates 2 and 3 and extend along the Web-plates or sections 3 and over the flange plates 5 and are 55 welded along the longitudinal edges of the webplates or sections 3. by welds 9 and also along the longitudinal and end edges of the flange plates 5, as at l0 and 11, respectively. The web sections 4 are an amount higher than the sections 3 equal to the thickness rof the flange plates 5 and 6 so 60 that their edge faces are flush with the outer faces of the flange plates 6. The third and outer flange plates 7. are of a length equal to the combined length of all the web sections 2, 3 and 4 and t extend along the whole beam. The flange plates '7 are welded along the longitudinal edges of the web sections 4`by weld 12 and along the longitudinal and end edges of the flange plates 6, as at 14 and l5, respectively. The above construction provides an integrally welded beam ha'ving a web and flanges of varying cross-section so as to provide maximum crosssection where the stress is greatest.

The invention `is shown in connection only with a shape analogous to an I-beam. But it may be applied to various shapes which are in general similar tol-beams but differ therefrom in the flanges or other laterallyprojecting portions a the edges of the webs. l

The invention is illustrated in connection with arc welding. But it is applicable also to shapes in which the parts are welded together by any one of various other known or suitable methods.

- It will be understood that while I have illustrated one specific embodiment of my invention, I do not wish Ato be limited thereto since various modifications may be made to accommodate the beam for carrying various loads.

I claimzvf 1. As a new article of manufacture, the struc- .tural shape, characterized by having a cross-section Within the limits' that may be rolled as an integral shape, whichcomprises integral flange and web portions formed of rolled metal plates and` continuous line welds uniting the flanges and longitudinal edges of the web portions into a unified structure, said web portion being composed of a p"'rality of relatively short lengths of rolled meta. )lates of varying thickness Welded end-to-end to form a continuous structure of t and continuous line welds uniting the flanges and longitudinal edges of the web portions into a unied structure, said web portion being coinposed oi a plurality of relatively short lengths of rolled'metal plates of varying thickness welded end-to-end to form a continuous structure of single plate thickness, and said ange portions beingcomposed of a plurality of plate sections of varying lengths mounted. one on top of the ipeaaeo andcontinuous line welds uniting the flanges and longitudinal edges of the-web portions into a unified structure, said web portions being'composed of a plurality` of relatively short lengths of rolled metal plates of successively less thickness toward the transverse center of the beam, said plates being welded end-to-end to form a' continuous structure of single plate thickness, and said iiange portions being each composed of one c'ontinuous rolled metal plate extending along the entire length of said beam, and other plates mounted on the inside face of said rst named plate and welded together and to said continuous plate by line welds, said last named plates extending between the Ajoints in said web so as to form a flange increasing in cross-section as the web decreases in cross-section.

ROBERT J. HARRY.

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