US 1915424 A
Description (OCR text may contain errors)
June 27, 1933. A. KERR METALLIC LTOIST I Filed March 14, 1928 Patented June 27, 1933 UNETED STATES PATENT ANDREW KERR, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOB TO MCCLINTIC-MABSHALL COMFANY, OF PITTSBURGH, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA METALLIC JOIST Application filed March 14, 1928. Serial No. 261,584.
This invention relates to a metallic joist and particularly to a metallic joist of truss form having the top and lower chords thereof formed of angle members, and having a web portion extending between the chords, said parts or elements being electrically welded together.
Among the objects of the present invention are, to provide a joist of the character specified, of simple and light construction, embodying the required side and vertical stiffness; a joist having its center of gravity near the middle and its supporting ends disposed in a plane above the center of gravity and of relatively shallow depth, whereby to provide stability and keep the height of a floor construct-ion, in connection with which the joist may be employed, to a minimum; and a joist construction comprising structural parts and elements of such character that they may be readily connected by electric welding.
Other objects and advantages of my invention will'be hereinafter pointed out or become apparent from a consideration of thefollowing description, taken in connection with the accompanying drawing.
In the accompanying drawing, which illustrates an application of my invention:
Fig. 1 is a side elevational View of a joist constructed in accordance with my invention;
" Fig. 2, an enlarged vertical sectional view, the section being taken on line 11-11 of Fig. 1;
Fig. 3, an enlarged detail perspective view, showing one end of the joist embodying my invention; and V Fig. 4, an enlarged vertical sectional view similar to Fig. 2, showing a modified form of webbing that may be employed.
Referring to the drawing, and as preferred, the top chord of the joist, designated generally by the numeral 5, includes two spaced apart angle members 6, each of the said angle members being preferably formed with a projection or rib 7 which may be rolled in the angle member 6. The purpose of this projection or rib 7 is to provide means for aiding in the welding of a web portion of the joist, hereinafter described, to the said angle members. 7
The lower chord of the joist, indicated generally by the numeral 8, is made up of angle members of, similar construction and arranged in spaced apart relation one to the other, as in the construction of the top chord of the joist. These lower angle members 9 are also provided with projections 10 corresponding with and functioning as the projections 7 of the angle members 6 of the top chord.
The angle members 9, constituting the lower chord of the truss, are bent upwardly adjacent their ends, as shown at 11, in a direction to meet the upper chord member 5 and are formed with horizontal extensions 12.
The said extensions 12 are adapted to be con nected to the end portions of the angle members 6 of the upper chord by horizontally extending members 14.
Members 14 are preferably welded to the angle members 6 of the upper chord and to COITGSPOIldlIlg' angle members 9 of the lower chord, and extend parallel with the upper chord angle members inwardly from the two ends of the joist to points adjacent to the diagonals or web portion of the joist. In addition to tyingthe said angle members together, as particularly shown by Fig. 3, it will be understood that these members 14 function to take care of the shear and moment.
Interposed between the upper and lower chords, and designed to be electrically welded thereto, is a web or webbing comprising a bent bar, rod, or other sectional member 13. It will benoted that the member 13 is bent so as to form diagonals and so that the bends of member 13 are positioned between the upper and lower pairs of angle members of the respective upper and lower chords; also, that the edges of the member13,"interposed between the adjacent faces of the respective upper and lower angle members, are arranged in contact therewith and with the projections 7 and 10 thereof. When thus positioned, the web member is joined to the anglesby 1Electrically welding it to the said angle memers.
15 designates vertically extending spacers for spacing and tying the angle members.
These spacers, one at each end of the joist, are
secured to the members by welding or otherwise. 5 In the form of Fig. 4, in place of the round member 13, I have shown a bent plate member 13a constituting the webbing of the j0ist., Otherwise, the joist of this form is the same as the form of Fig. 2.
1. A welded joist comprising an upper pair of laterally spaced apart L-shaped angle members constituting the upper chord of the joist, a lower pair of laterally spaced apart L-shaped 15 angle members constituting the lower chord of the joist, said lower chord having its ends bent upwardly to meet the upper chord, tie
-- and shear plates located at the ends of the joist, and a bent web member interposed be- 29 tween the chords having portions entered between the pairs of angle members and electrically welded to said angle members.
2. A welded joist comprising'an upper pair of laterally spaced apart L-shaped angle members constituting the upper chord of the joist, a lower pair of laterally spaced apart L-shaped angle members constituting the lower chord of the joist, said lower chord having its ends bent upwardly to meet the upper chord, shear plates located at the ends of the joist and connecting the angle members of the top and bottom chords, spacer members positioned adjacent the ends of the joist, and a bent web 'member interposed between the chords and 5 electrically welded to the respective pairs of angle members.
3. A joist comprising an upper chord and a lower chord, each chord consisting of angle members having transversely alined flanges 0 and upright flanges at their inner edges, the end (portions of thesangle members of one chor being arranged adjacent to the angle members of the other chord, with the upright flanges in alinement, a web welded to the facing surfaces of. the upright flanges, and shear plates at the ends of the joist located between the lateral flanges of the chords I and welded against the outer surfaces of the upright flanges. I 4. A joist comprising an upper chord and a lower chord, each chord consisting of angle members having transversely alined flanges 'T and upright flanges at their inner edges, the end portions of the angle members having 0 their upright flanges in edge contact, a' web welded to the facing surfaces of the upright flanges, and shear plates at the ends of the. joist located between the lateral flanges of the chords and welded against the outer surfaces of the uprightflanges.
In testimony whereof I aflix my signature. ANDREW KERR.
CERTIFICATE OF CORRECTION.
Patent No. 1,915,424. June 27, 1933.
it is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as foiiows: Page 2,, lines 21 and 22, claim 1, strike out the word "electrically"; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the ease in the Patent Office.
Signed and sealed this 22nd day of August, A. D. 1933.
M. J. Moore. (Seal) Acting Commissioner oi Patents.