US1774423A - Fabricated metallic structure - Google Patents

Description

Aug. 26, 1930. w. DAL'roN FABRICATED METALLIC STRUCTURE 3 Sheets-Sheet 1 Filed 'May 2. 1927 Inventor.: William Dalto,

His Akbar-neig.

Aug. 26, 1930. w. DALToN FABRICATED METALLIC STRUCTURE Filed May 2. 1927 3 Sheets-Sheet 3 II'III/flllllll Inventor- William Dalton b5 W@ His Attorrjeg Patented Aug. 26, 1930 TATES PATENT OFFICE.

WILLIAM DAITON, OF SCHENECTADY, NEW YORK, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK FABRICATED METALLIC STRUCTURE Application led May 2,

The present invention relates to fabricated metallic girders or trusses for building construction and the like, and more particularly to structures of the above type which are f; fabricated from standard rolled sections.

- I-beams for example, with the ianges thereof standing vertically and with the webs lying horizontally and parallel with each other. rlhus the flanges which are parallel, lie in planes parallel with the plane of the normal load to which the structure is subjected. In the usual building construction, this is in a downward vertical plane. For a given weight of metal, H-beams provide a maximum resistance to compression, and, by so placing the H-beams in the chords of the truss, the full strength of that type of beam may be utilized with a saving in weight over other types heretofore used. Furthermore, by so placing the H-beams, the same desirable type of beam may be then utilized for com pression members connecting the chords, such members being constructed from standard rolled sectionsv which permit effective, easy welding to the chords. Simple channels complete the structure and form the tension and end members. The channels are also so arranged that they are easily and effectively welded to the chords. As used throughout the speciiication and claims, the term H- beam is used generically to designate beams of that general cross section, that is, beams having parallel flanges united by a central web, such as an I-beam, which in cross sectional shape is an H-beam with the web elongated.

For a further consideration of what is believed to be novel and the invention, atten- 1927. Serial No. 188,086.

tion is now directed to the accompanying drawing, the description thereof and the appended claims.

In the drawing, Fig. 1 is a side elevation of a truss embodying the invention; Fig. 2 is a section on a greatly enlarged scale taken through line 2-2 of Fig. 1; Fig. 3 is a section taken on line 3 3 of Fig. 2; Figs. 4 and 5 are details of end connections between the chord members and the tension and compression members of the truss; Fig. 6 is an enlarged side elevation of one end of the truss shown in Fig. 1; Fig. 7 is a section taken on line 7 7 of Fig. 6; Fig. 8 is a side elevation of a modified arrangement of the truss shown in Fig. 1; Figs. 9 and 10 are figures show ing details of the truss of Fig. 8, Fig. 10 being a sectional view taken on line 1010, Fig. 9, Fig. 11 is a sectional view of a detail of Figs. 9 and 10 taken on line 11-11, Fig. 9; and Fig. 12 is a sectional view similar to Fig. 10 showing a further modiiication adapted to the girder arrangement of Fig. 8. With the exception of Figs. 1 and 8 which are on the same scale, all of the iigures of the drawing are on the same enlarged scale.

Referring to Fig. 1 of the drawing', 10 and 11 are the upper and lower or compression and tension chords respectively of the truss or girder and are joined by compression members 12 and tension members 13 of the proper size and strength to carry the compression and tension loads for which the truss is designed. The truss is provided with end support members 14 which are joined to the upper and lower chords. The general arrangement of chords and connecting members shown represents a common form of truss or girder for building construction and which is readily adapted for fabrication in accordance with the present invention.

Referring now to Figs. 2, 3, 41: and 5, in which the same reference numerals as in Fig. 1 are used for like parts, it will be seen that the upper and lower chords 1-0 and 11 respectively are simple beams of H-shaped cross-section with the webs parallel and the flanges standing vertically. Other beams of this general cross-sectional shape, such as I- beams, may be used however as before mentioned. Chords embodying flanged beams of such general cross-sectional sha-pe, particularly H-beams, are not only less costly than ordinary angles and plates for a given strength but are stronger for a given weight.

Vit-h the ianges vertical, the faces thereof are presented in such a manner that compression and tension members of standard section are readily welded thereto. In the present example, the compression members 12 are oppositely disposed T-beams of standard section with the flange faces of the Ts Welded to the inside faces of the vertical flanges of the H-beams as indicated at 15 and along the edge of the H-beam flanges as indicated at 16. This provides three continuous welds between each compression member and the iiange of the chord member as shown in detail in Figs. 3, Ll, and 5. The welds with the bottom chord as indicated in Fig. 2 are in the same relative places between the T-faces and the flanges of the bottom chord.

In certain cases where additional strength of bonding with the chords is desired, the webs of the T-beams are made to abutthe webs of the chords and are there welded as indicated at 17. All of the welds are so located that they form an effective bond between the members and are not diflicult to place by ordinary welding equipment means.

The T-beams are united in pairs after being welded to the chords to form in substance and effect a single compression member of the general I-beam or H-beam form as indicated more clearly in Fig. 3. They are united preferably by struts 18 spaced along and between the adjacent webs and welded in place as indicated at 19, Figs. 2 and 8. The struts are sufficient in number to provide a web of sufficient strength to prevent buckling or bowing of the nish-ed compression member when under load. The H-beam chords are thus united by compression members of H-beam form, the struts and weldinowhich unite the T-beams and complete the ql'l-beam construction of the compression members be ing adapted to compensate for irregularities in the spacing between the T-beams caused by irregularities in the dimensions of the T- beams and H-beam chord fianges affecting the spacing.

The tension members 13 uniting the upper and lower chords are also oppositely disposed with respect to each other in pairs and in the present example are U-shaped channels -of standard section. The channels are readily adapted to lie flat against the outer faces of the chord flanges and are welded thereto along edges adjacent the chord flange faces as indicated at 20. Both ends of the channel members are welded in a similar manner. The welding of the channels and the top chord is indicated in Fig. 2 and more fully in Figs. 3 and 5. Additional welding if desirable or necessary may be made at the ends of the tension members after the manner of the welding 17 at the ends of the compression members.

Along the top flanges of the upper chord are welded short plates 23, Fig. 1, which are suitably spaced to provide purlin seats at desired locations. rIhese plates are welded as indicated at 22, Figs. 2 and 5, along their edges, to the edges of the chord flanges. To provide additional strength along the center of the span when required, additional metal in the form of plates may be weld-ed to the webs of the chord members. Such additional strengthening metal is shown in the present example in connection with the lower or tension chord member of the truss in the form of a plate 24 (Fig. 2) which lies along the under side of the web and which is secured in place by continuous welds 25. r1`he plate is of sufficient length and thickness to provide the desired additional strength for the lower chord. As is obvious, the upper chord may be strengthened in a similar manner.

It will be noted that in the structure provided, there are comparatively few parts, namely a top and bottom chord, each in one piece of simple standard l-l-section for maximum strength and minimum weight and strengthened if necessary by a simple fiat plate, and only two other' section types for the tension and compression members, namely simple channels and T-beams, each being a type adapted to lie flat with surfaces of the chord fianges. rlhe T-beams are joined by suitable strut pieces to provide integral l"- beams as compression members. The structure thus comprises a pair of l-l-beams or beams of that general cross-sectional form as chords, with connecting compression members of the same type, and connecting tension members of simple channel section.

To fabricate trusses of this type thus requires only a few standard sections of relatively low cost and embodying desirable features of strength with low weight. By using these sections in the manner shown, welding is easily and effectively accomplished. Furthermore, welding permits a construction which would be impractical with riveting. For example there is no piercing and wealtening` of the chord flanges which riveting would necessitate.

To complete the simple welded structure, the end plates 1li are provided in the form of wide channels as shown more fully in Figs. 6 and 7. The channel fianges are cut away at the ends to receive the ends of the H-beam chords as indicated at Q6. Clearance spaces are provided between each H-beam and the cut flanges of the end channels to permit welds 27 to be made between the H- beam flanges and the cut channel flanges. End welds are also made in the open channels of the H-beams between the flanges and webs of the latter and the inner faces of the end channel members as indicated at 28, thus eectively uniting the parts.

Referring particularly to Fig. 2, it will be seen that the truss is not only well adapted to support normal load in a direction parallel with the plane of the flanges of the chord members, but is of such construction that it is highly resistant to buckling in a direction transverse thereto. The solid vertical flanges of the H-beams connected by solid webs provide great strength against transverse load, particularly as arranged in accordance with the invention to be united by the tension and compression members without being pierced in any way for the purpose of fabrication.

Referring now to Fig. 8, and 3l are the upper and lower chords of the truss which are united by compression members 32, tension members 33 and end support members 34. This truss construction is similar to that shown in Fig. l but employs compression members which stand vertically or at a right angle to the chords. This permits still further simplification of the truss construction and the work of fabricating it, as will be seen with reference also to Figs. 9, l0 and ll, wherein the same reference numerals for like parts are used as in Fig. 3.

By the use of compression members which stand vertically or at a right angle to the chords, the ll-beam construction thereof, as carried out in the previous embodiment by fabrication from l`beams, is greatly simplified. In this embodiment standard rolled sections of the general irl-beam or I-beam type are placed between the chords as indicated in Figs. 9 and 10 and are welded to the edges of the chord flanges along their webs which are placed in the planes of the flanges. The compression members are cut to such length that a slight clearance space is provided between the edges of the chord flanges and the webs of said members and these spaces are filled with the weld bead as indicated at 35. Since the compression members stand vertically or at` a right angle to the chords and transmit a compression load, any suitable weld may be used which will hold them in position. l/Vith this construction only the simplest fabrication is necessary. The compression members are of standard rolled section, preferably standard H-beams or I-beams of lthe general shape shown in section in Fig. ll, cut to the proper length to stand between the chords and held in position by four simple welds.

In the case where a lighter compression load is to be taken through the compression members, one member 36 may be used instead of a pair as shown in Fig. l2. In this modification the web of the chord is strengthened by a plate 37 welded thereto as indicated at 38. The plate forms a footing for the single compression member which stands vertically or at a right angle thereto and is welded along its lianges to the plate as indicated at 39. In this arrangement the single compression member stands substantially midway between the chord flanges as shown.

In the truss construction of Fig. 8 and associated Figures 9, 10, ll and l2 the same type of tension members 33 are employed as in Fig. l and associated Figures 2, 3, 4, 5, G and 7. These are simple channels welded to the chord flanges as indicated at 3G, the weld beads being of substantially equal length. In this truss construction the ends of the tension members, as well as the ends of the compression members, are cut square, that is, sawed or cut straight across in the usual manner without angles, thereby simplifying the cutting and fabrication to an appreciable extent.

The purlin plates or seats shown at 37 are also made of such width that they overlap the flange edges of the upper chord as shown in Figs. l0 and l2. Thus they do not require accurate cutting and placing to the same degree as the plates in the truss of Fig. l. lVith the overlapping plates the weld bead is placed below the plate as indicated at 38.

The lower chord is not shown in detail for the reason that the various members are connected therewith in a similar manner to the connections with the top chord as shown. Likewise the end plates 3e and connections therefor are not shown in detail as they are the same as shown in detail in Figs. 6 and 7 and described in connection with said figures.

This girder or truss construction thus fol-' lows the arrangement of Fig. 1 in that it comprises chords of the general H-beam form having their webs parallel and flanges vertical, and connected by simple channel shaped tension members and compression members of the general H-beam form the compression members standing between the chords with their webs in the planes of the chord flanges and being suitably welded to the chord flanges to hold them in place. In this construction all of the members have plain ends, that is, they are simply sawed or cut to the desired length without additional cutting to various angles thus greatly simplifying the preparation for fabrication as well as the actual fabrication itself. For example the compression members are merely secured in position as they stand between the chord flanges by a single continuous weld at each end along the web.

In connection with Figs. 2, 4, 5 and 9, it should be noted that the center lines of the webs of the H-beam chords, compression members and tension members intersect. This is characteristic of all joints between the chords of the truss and the compression and tension members throughout the various embodiments shown and is the preferred construction in any girder or truss structure fabricated in accordance with the invention. Vith this construction the compression and tension forces are applied in the chords in planes which intersect in the neutral axes or webs of the chords thereby reducing the tendency to set up distorting component forces and obviating the necessity for additional or complicated welding to meet such Jforces. Stated in another Way, the center lines of the compression and tension members intersect a common transverse center line of the web of the chord to which they are joined.

What I claim as new and desire to secure by Letters Patent of the United States, is

l. A fabricated girder structure comprising H-beam compression and tension chords having their webs parallel and their side fianges in parallel planes, tension members uniting said chords, said tension members comprising U-shaped channel bars the ends of which overlap the flanges of the chords with their transverse walls in engagement therewith and welded thereto, and compression members uniting said chords, said compression members comprising bars of H-beam section.

Q. A fabricated girder structure compris` ing` H-beam compression and tension chords having their webs parallel and their side fianges in parallel planes, tension members uniting said chords, said tension members comprising U-shaped channel bars-the ends of which overlap the flanges of the chords with their transverse walls in engagement therewith and welded thereto, and compression members uniting said chords, said compression members comprising H-beams the webs of which lie in the planes of the chord flanges and are united thereto b v welding.

In witness whereof, I have hereunto set my hand this 30th dav of April, 1927.

WILLIAM DALTON.

Images