US1751747A - Trussed structure - Google Patents

Description

March 25, 1930. F. H. MOYER ET AL THUS SED STRUCTURE Filed May 21 1926 5 Sheets-Sheet l March 25, 1930. F MOYER ET AL TRUS SED STRUCTURE Filed May 21 1926 3 Sheets-Sheet 2 March 25, 1930. MOYER ET AL TRUSSED STRUCTURE Filed May 21, 1926 5 Sheets-Sheet 3 u lllriub f I iww fi w mwU F v Patented 'Mar. 25, 1930 UNITED STATES PATENT OFFICE IBEDELLIA H. MOYER, OF PITTSBURGH, PENNSYLVANIA, AND CARL A. FRAHM, F

MASSILLON, OHIO, ASSIGNORS, BY MESNE ASSIGNMENTS, TO THE BERG-EB. MANU- FACTURING COMPANY, OF CANTON, OHIO, ACORPOR-ATION OF OHIO TRUSSED STRUCTURE Application filed May 21,1926. Serial No. 110,717.

This invention relates to trussed structures and particularly to that class known generally as metal lumber, that is, to light weight trussed structures .of metal bars fabricated into beams, joists, columns, struts and the like.

An object of our invention is to provide a trussed structure in which the mass of the metal isdistributed to the greatest advantage to insure the maximum strength for a given weight. An object is to provide a trussed structure of light Weight and in which the component parts are of such form that they may be manufactured, assembled and united in a simple, eflicient and economical manner. Another object is to provide a trussed structure in which the web bars terminate at their points of contact with the tension chord but include portions extending along the compression chord to reinforce the same. A further object is to provide a trussed structure in which the web includes a plurality of bars-each of which is shaped to asubstantially triangular qutline. A fur- .2 ther object is to provide an improved end plate construction. in which relatively light weight can be used for a. given loading.

These and other objects of the invention will be apparent from the following specification when taken with the accompanying drawings which illustrate preferred embodiments of our invention.

In the drawings: Fig. 1 is a fragmentary side elevation of a joist or floor beam embodying the invention; Fig. 2 is same;

Fig. 3 is a fragmentary perspective view of "one end of the joist;

Fig. 4 is a vertical section on line 4-4 of Fig. 1; I

Fig. 5 is a fragmentary side elevation of a modification;

Fig. 6 is a broken plan view of the same; Fig. 7 is a vertical section on line 77 of Fig. 5;

Fig. 8 is a fragmentary side elevation of a further modification;

a fragmentary plan view of the Fig. 9 is a fragmentary plan view of the same; i

Fig. 10 isa vertical section on line 10-10 of Fig. 8; and

Figs 11, 12 and 13 are fragmentary side elevations of still further modifications.

In the drawings, the invention is illustrated as embodied in a-trussed structure comprising a compression chord G, a tension chord T, a web 7 and end supports S. The

compression chord takes the form of a pair of parallel bars 1 which are spaced apart to increase the width of the chord or flange, and the tension chord T is similarly constructed of parallel, spaced bars 2. The web W is provided by a plurality of bars, each of which is bent to a substantially trinagular contour having a base 3 and sides 4, which sides are preferably of equal length. The triangular web elements are arranged in the trussed reinforcing the bars 1 of the compresslon chord C and with the sides 4 extending to and terminating at the tension chord T. As

shown in Fig. 4, the center line of the base than the spacing of the chord members and the outer portions of the plates are notched or cut back by the removal of a rectangular portion 6-, which portion is then arranged as a bearing plate for the notched vend 7 and is welded thereto. The lower outer corner of the deeper section 8 of each plate S is provided with an opening 9 for receiving one end of a furring strip or extension rod 10, the

a other end of the angular rod being attached to and inline with the tension chord. The ends 11 of the tension bars 2, outside the end'web members, are bent diagonally outward to lie along the opposite faces of the adj acent end plates S. As shown in Fig.

structure with their bases 3 lying along and but we have found that s 1, the bent ends" 11 extend into contact with the shallow supporting section 7 of the plate S but are spaced from the lower edge thereof, and are also spaced from the top chord bars 1.

contacting surfaces of the web and flange bars may be welded throughout their length, pot welding would develop the full strength of the assembly. The sides 3 of the web triangles are preferably spot welded to the top chords at the points Y and the abutting ends of the sides 4 are welded to each other and to the tension flange bars 2, as indicated at Z. As stated above, the bearingplate 6 iswelded to the outer portion 7 of the end plate and the plate is spot welded to the adjacent surfaces of the flange bars 1- and 11. The inner edge 5 of the plate S is preferably welded throughout its length to the abutting surface of the end web bar 4.

The embodiment illustrated in Figs. 5, 6 and 7 involves the use of web elements W which are substantially triangular in outline but in which the bases 3 of the respective triangles are concave or bowed downwardly to provide individual truss constructions which add to the compressive strength of the top chord. As in the preferred embodiment, the contacting surfaces of the top chord members 1 and the bars 3 are spot welded as at X, and preferably short. bar sections; or slugs 12 are inserted between the chord members and the center of the bars 3' and are welded to'the web and chord.

In the modification shown in Figs. 8-10 inclusive the web W is formedof a plurality of inverted triangles having their bases 13 arranged parallel to and spaced below the top chord members 1. The necessary rigid connection between the web W and chord C is ef fected by short slugs or bar sections which are arranged between and welded to the web and flange. The slugs 14 overlie the adjoining apexes of the triangular elements, and additional slugs or sections 15 are provided at the center portions of the sides 13.

As described above, the opening or joint in the triangular elements has been placed at tlp: apex of the two sides 4. which extend to th tension bars 2. vAs shown in Fig. 11,

the joint or opening A may be located at'the junction of one side bar 4 with the top chord C, or as shown in Fig. 12, the joint may fall at the center of theinverted base 3 of the triangular elements. As shown in Fig. 13, the web elements take the form of inverted right triangles having a side 16 lying along and secured to the compression chord C and having sides 17, 18, which extend to and ter- 1 Ininate at the tension chord T.

It-will be noted that the reinforcement of the compression flange C-by the sections of the web IV is effected without adding to the mass or weight of the tension flange T. In a metal beam or joist construction the tension stress can be carried by a cross-section which is materially less than the area required for the compression load. By increasing the effective cross-section of the compression flange without adding to the tension flange, we are able to make the most effective use of the mass of metal in the assembly. The use a further economy in weight since the bent ends 11 of the tension bars are carried past the inner end of the bearing plate 7 and act as a reinforcement against vertical shear. Tests on trussed structures embodying the invention have demonstrated that the truss has a greater load-carrying capacity than previous constructions of the same weight.

Although we have illustrated our invention as embodied in structures assembled from rolled metal bars of circular cross-section, it will be understood that the invention is not limited to any particular cross-section of the component parts, and the term bar is therefore to be read as a generic term for rods, tubes, strips or the like. Since many of the advantages are dependent upon the shape and arrangement of the parts employed and not upon the particular methods or means for assembling the same, it will be apparent that the structures may be rigidly assembled by riveting, welding or'cold-forging. The relative size and arrangement of made in the several parts, their relative size,

shape and location, without departing from thespirit of our invention as set forth in the following claims. a

We claim: 1. In a trussed structure comprising metal bars arranged as spaced flanges and a web connecting the same, a plurality of bars forming the web, each of said bars beingbent to the outline of a closed geometric figure and arranged with the ends of the bar adjacent each other and adjacent one of said flanges, and means securing the said adjacent ends to each other and to the adjacent flange.

2. In a fabricated truss, the combination which has a portion in alinement with said lower chord.

3. The combination with a plurality of bars arranged as a truss having a tension chord, a compression chord of greaterlength than said tension chord, end bearing plates of less depth than said truss, and end shear members extending upwardly andoutwardly from said tension member and having portions secured to the respective end bearing plates, of an extension rod having a portion afiixed to j and providing an extension in line with said tension chord, and a second portion extending therefrom and secured to the adjacent end bearing plate.

4. A trussed structure comprising a tension flange, a compression flange formed by a pair of parallel bars spaced apart to increase the flange width, web members extending between said flanges and having portions lying along said compression flange, the said porsion chord, a tension chord of less lengthtions of the web members ing bowed down wardly away from said compression flange,

and fillers inserted between saiddownwardly bowed portions and the bars of the compres-- sion flange.

5. A fabricated truss comprising a 'plurality of bars assembled to form a compresthan said compression chord, and web members between said chords the end web mem-, bers being formed by the ends of the tension chord bar which project beyond the ends of tween the compressionbars and contacting therewith and with the adjacent sides of the triangularweb members, the said fillers' be in welded'to-the flange and web bars.

A truss comprising'bars forming in part the upper chord, bars forming the lower chord, and a series of separate bars each bent in the form of a trian le, the base of each being merged into and orming part of the upper chord and the free ends of same forming the apex of the triangle and connected together' and attached to the lower chord bars, the sides of said triangular arranged bars forming the web members of the truss. 4

8. A trussed structure comprising compression and tension flanges, each'of which is formed of a pair of parallel bars spaced-apart to increase the flange width, a plurality of web bars each bent to a substantially triangular contour, and having one side bowed' inwardly toward the opposite apex of the triangle, the said bowed side of each, triangle extending within the gap between the bars 01' the compression flange, the said opposite apex of each triangle being arranged within the gap between the tension bars, and fillers inserted between the central portions of said bowed sides of the triangular members and the bars of the compression flange, the web In testimony whereof, we afiix our signatures.

FREDELLIA H. MOYER. CARL A. FRAHM.

the tension chord and extend upwardly at an 1 angle to and terminatesubstantially at the 1 compression chord bar, and a bearing plate at each end of said truss and extending past the adjacent upwardly bent end of said-bottom chord bar to contact with the next web member, said plate being secured to the compression chord bar, the bent end of the tension chord bar and the said nextweb member, the said end bearing plates and thecompression' chord bars projecting beyond the ends of the compression chord.

6. A trussed structure comprising compression and tension flanges, each of which is formed of a pair of parallel bars spaced apart to increase the flange width, and a plurality of web bars each bent to a substantially triangular contour and arranged with one side 4 thereof lying along the compression flange, the apex of the triangular members being arranged within the gap between the tension bars, and fillers inserted within the gap be-

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