US3158925A - Method of making a purlin or roof truss - Google Patents

Description

Dec. l, 1964 w. s. EDGE 3,158,925

METHOD OF' MAKING A PURLIN OR ROOF TRUSS Original Filed April 16, 1956 United States Patent O 3,l58,925 METCHGD Si? MAKING A PURLN 6R RF TRUSS Walter S. litige, deceased, inte of Kansas ity, Mo., by Helen M. Ed e, heir, Kansas City, Mo., assigner to Keystone Steel Wire Company, Peoria, ill., a corporation of Delaware Griginai application Japr.. i6, 1956, Ser. No. 575,252. Divided and this application .italy S, i963, Ser. No. 293,562 f 4 Ciaims. (Si. 2Q-4155) This invention relates to a method of making a purlin or roof truss.

This application is a division of parent application, Serial No. 578,242, tiled April 16, 1956 and now abandoned.

The structural member made by the improved method is employed particularly in the construction of roofs and oors in building and other structures, wherein concrete or gypsum or similar liuid materials are poured over the structural member to form a permanent deck or slab.

in the construction of poured root decks or doors concrete or gypsum is frequently poured in a quite fluid state, and unless the structural member provides a tight joint in the roof structure, leakage may occur, which is highly undesirable. This improved method provides a structural member having upper and lower chords and a web portion made of continuous wires or rods, said web portion having obliquely extending portions connected by curved portions so as to form a zig-zag web member, the lower chord being made up of a pair of angle members, which may be referred to as base angles. In such a structure it is highly important, when used in a poured roof, deck or licor structure, to provide a liquid tight joint between the two base angles so that no leakage can occur at this point through the lower chord of the structural member.

The method of the present invention provides a structural member in which the lower chord is made up of a pair of angle members or base angles, made of continuous sheet steel strips that are so related and connected together as to provide a closure between the upstanding legs of the angle members, which are adjacent each other, throughout the length of the structural member, whereby the joint between said base angles can be tightly closed against leakage and a structural weakness which exists in bar joists, is avoided.

It is a further purpose of the invention to provide a bottom chord or base member in a structural member of the above mentioned character, which comprises a pair of members that are of such a character that they will lend themselves to the welding of said members to the bent web member and toV the ,welding of the two parts or" the base member to each other by a continuous welding process. Y

it is a specific purpose of the invention to provide a continuous process of making a structural member of the above mentioned character comprising continuously progressively straightening a pair of rods, continuously progressively forming uniformly spaced oppositely directed bends in a rod, leading the three members into a guide with the straight rods in engagement with the opposite sides of the bent rods adjacent one set of the bends, continuously bending a pair of continuons sheet steel strips to form continuous angle members, having lateral beads thereon, and feeding said steel angle members with one of the ilanges of each thereof in engagement with opopsite sides of the bent rod at the other set of bends therein and said bends in Contact, progressively welding the bent rod to the straight rods and angle members to provide the web portion of the structural member connecting the chords made up of the straight 3,153,925 Patented Dec. 1, 1964 ice rods and the angle member and continuously Welding said beads to each other to form a continuous structural member of indefinite length and then shearing the resulting continuous member into any desired lengths that may be required,

Other objects and advantages of the invention will appear as the description of the drawings proceeds. I desire to have it understood, however, that I do not intend to limit the invention to the particular details shown or described except as defined by the claims.

in the drawings:

lF'lG. l is a fragmentary perspective view of the improved structural member made by the new method.

PEG. 2 is a fragmentary cross sectional view through a root or similar structure, showing the improved structural member mounted therein, and

FIG. 3 is a fragmentary cross sectional View on an enlarged scale through the improved structural member, the thickness of the coating shown thereon being somewhat exaggerated.

Referring in detail to the drawings, a structural member is shown in FlGS. l and 2 that has the upper chord thereof made up of a pair of continuous straight rods or Wires 4, which extend parallel to each other in uniformly spaced relation. The lower chord or" said structural member is made up of a pair of angle members 5 that have upstanding legs 6 and horizontal legs 7, said horizontal legs being ot much greater extent than the vertical legs. Extending between the upper and lower chords is a web portion that is made of a continuous wire or rod and which has obliquely extending oppositely inclined portions S and 9 that are connected together by upper bends lil and lower bends 1l. Thus the web portion is formed oi a continuous rod or wire round in cross section, that extends in Zig-zag arrangement between the upper and lower chords of the structural member and connects said upper and lower chords together.

The web portion and the upper and lower chords are connected together, by pressure resistance elec-tric welding. Thus the straight parallel rods or wires 4 are connected together and connected with the web portion by welds joining the web forming rod or wire with the rods or wires 4 adjacent Ithe bends l0 in said web member, as shown at l2 in FlG. l. While the bends 1t) are shown as extending slightly above the tops of the rods 4, this is not absolutely necessary. The upstanding anges 6 on the base angle members 5 engage opposite sides of the lower bends l1 of the web forming rod or wire and are welded thereto in a similar manner to that of the welding of the web forming rod or wire to the rods 4, as is illustrated in FlG. 3.

The horizontal legs 7 of the base angles or angular bottom chord members, have oppositely inclined odset portions 13 extenmg obliquely upwardly from the main body portions of said iianges 7 and downwardly oppositely inclined oblique porti-ons 14 extending from the portions 13 to thus form a rib 15 between the portions i3 and i4 on the upper side of each :dange 7 adjacent the outer extremity 16 thereof, the angularity of the portions l and i4 to each other at their junction providing a break on the outer side of the bend formed by said otlset portions that will provide an edge or ridge, providing line contact between said flanges 7 and board members i7, that serve both as forms for the material that is to form the main body portion of the roof or door and as permanent facing members remaining in place after the concrete or gypsum torrning the main body portion of the roo.F or door is poured and has set. The board members 17 can be made of a plurality of plies and when such is the case the same comprise an inner ply l of relatively hard material, and outer plies 19 of softer material, which would be slightly indented by the rib or 3 ridge` formed at 1S on the horizontal flanges 7 so as to provide a seal between the ply 19 and said anges 7.

The upstanding legs 6 of the base angle members 5 are provided with offsets 2li that are directed toward each other and run continuously lengthwise of the ilanges 6 throughout the length thereof, said olsets'being of such depth that the same will be in contact with each other at the1r crests when a' bend 171 of a web member is in posit1on between thepair of langes 6. Preferably, the oitsets Ztl Vare of the specific shape shown in FIG. 3 so as to get Said oisets at as low a position in the vertically extending anges 6 as 1s possible, or in other words, as closely adiacent the horizontal flanges 7 as is possible. In orderto accomplish this the anges or Vlegs 6 are offset toward each other at an oblique angle in the upper portions of said offsets, as indicated at 21 in FIG. 3, and from the point ofrcontact of said inclined portions 21 with each other the curved portions 22 extend to the flanges 7. Thus, each odset has a planar portion 21 and a cur-ved portion 22.

It will be obvious that when the two angle members are assembled in the manner shown :in the drawings a pocket, for the lower bends 11 of the bent wire forming the web portion of the structural member, is provided between said flanges and that the inclined `portions 8 and 9 are also c onnedadjacent the bends 11 between said ilanges and 1n engagement therewith. It will be further noted that the odset portions form continuous longitudinal beads Vthat are in engagement with each other throughout the length of the structural members and are located belowthe bends 11 of the web forming member.

' The twoVV angle members 5 are welded to each other at the 'offset portions 22, as will be obvious from FlG. 3, andV the upstanomgrleg portions 6 thereof are welded to the web forming member at the bends Hand along the inclined Yportions 8 and 9 where these lie in contact with the legs 6.

In doing the welding of the structural member preferably, this isdone by a continuous process which const1tutesustraightening the two wires or rods 4 continuously by means of a continuous straightener, forming the bent web portion by a continuous bending process, leading the tnree memberscomprising the pair of rods or wiies 4 Vand the bent rod or wire comprising the web portion into a guide, continuously forming two continuous strips of sheet steel into two similar angle members 5 and feeding the three rods or wires and the two continuous angle membersA through two welding Vmachines equipped with two pairs of roller welding wheels, whereby the web member is welded to the two"V angles and the two upper chord members and the two angles welded to each other at the crests 'of beads 2l), and then shearing the continuous structural member to lengths desired by means ofil y a flying shear.

In FIG. the structural member forming the subject matter of the invention is shown Vas being mounted in position in .a floor oriroof structure that is provided with the Y board-like form members i7, which are preferably mounted on the legs 7 of Vthe lower chord of the structural `member. in slightly spaced relation, as shown in FIG. 2

and the concrete, or gypsum, or similar plastic materialiV in a fluid state, is poured onto^the structure made up of Y Y the membersjl'l'and the structural members to form the slab shown in FIG. 2, the concrete `or gypsum slab being indicatedby'the numeral 23 therein.

' It will beV obvious that this material, which is quite iuid,

will ow Yinto 'the spaces'24 between the endsof the the V-shaped groove formed between the portions 21 ofV the bends 11 by means of continuous bead-like rib formations, such as the oisets 2), that are in engagement with one another and welded to each other at their crests throughout the length of the structural member 6. The point of engagement of said offsets 2l? forming said inwardly directed beads or ribs on the llanges 6, where the continuous weld is made, is indicated in FIG. 3 by the numeral 25. Y

While a metal to metal Contact would not provide an absolutely water-tight joint between the base lianges 7 at the zone of engagement 2S of said ribs or beads, structural members of this character are ordinarily painted, preferably, by a dipping method, the coating material being indicated by the numeral 26 in FIG. 3. Said coating i material will ow around the bends 11 and will lodge in the legs d above the curved portions 22, as indicated at 27, and will similarly lodge in the groove between the curved portions 22 as indicated at 28, forming a double sealing coating at said point of contactrof said ilanges 6,

Vproviding a completely water-tight joint Vso that not any of the liquid in the slab forming material 23 can leak through between the flanges 6 and downwardly below the same. Similarly, because Voli the sharp corners at the continuous ribs 15 on the flanges 7, a seal isprovided between the composition board-like members 17 andthe ilangesr'? so that none `of the material 23 nor any liquid contained therein will escape between the flanges 7 and said board members 17 Also the offsets or beads formed by the offset portions i3 and 14 on each of the flanges 7 stilen the ilangesland makes it possible to use lighter gauge steelthan would otherwise be possible for the angles 5, and in addition assures that a straight edge will exist along each of the extremities Voi the anges 7 at 16.

What I claim is: L

l. In the process of making a structural member having an upper chord comprising a pair of rods, a lower chord comprising a pair of angular members and a web portion comprising a rod having oppositely inclined obliquely extending portions extending between said upper and lower chords, continuously progressively straightening a pair of rods of indenite length, continuously progressivelyv forming alternately oppositely directed, spaced bends in a rod of indefinite length,'leading said three rodsY into Va guide with said pair of rods in engagement with opposite sides of said bent rod at one set or said bends, progressively transversely bending each of a pair of sheet metal strips of indefinite length to form an angular member having an upstanding flange and a horizontal flange connected by abend, said bends being odset to form abead on each of said angular members projecting laterally` from said Vupstanding ilangerin an opposite direction to said horizontal ilange, feeding said pair of resulting continuous angular members with the upstanding flanges thereof inY engagementl withfrthe op-n posite sides of said bent rods. at theother set of bendsVlr therein and the crests of said beads in engagement with each other, progressivelyweldingV said straight rods and said upstanding flanges vto said bent rods andV said: beadsY to eachother as said rods and angular .members areV 2. vInthe process of making a structuralmember'hav- I ing an upper chord comprising a pairof rods, a lower Y boards 17 and the anges 6, andwill also ilow between i Ythe paired anges V6, as willfbe obvious from FIG. l, as

there are long `open spaces between the bends 11 Vlocated between the flanges 6. Forthi-s reason it is highly desir-Y able that a closure be provided between the flanges 6 that Ydirilicult to obtain such a closure in a welded structure of Y willgconiine this material, and it has been found to be chord` comprising a pair of angular members and arweb portion comprising. va rod having! oppositely inclined obliquely extending portions extending between said upper sively forming alternately oppositely directed, spaced bends in a rod of indefinite length, leading said three Arodsinto a guide withsaid pair of rods in engagementwith opposite sides of said bentV rod atone set of said` bends, progressively transversely bending each of a pair. of sheetmetal strips of indeinitelength totorm an an-v gular member having an upstanding iiange and a horizontal ange connected by a bend, said bends being offset to form a bead on each of said angular members projecting laterally from said upstanding ilange in an opposite direction to said horizontal ange, feeding said pair of resulting continuous angular members with the upstanding anges thereof in engagement with the opposite sides of said bent rods at the other set of bends therein and the crests of said beads in engagement with each other, progressively pressure resistance electric welding said straight rods and said upstanding flanges to said bent rods and said beads to each other as said rods and angular members are advanced, and shearing the resulting continuous welded member into desired lengths.

3. In ythe process of making a structural member having an upper chord comprising a pair of rods, a lower chord comprising a pair of angular members and a web portion comprising a rod having oppositely inclined obliquely extending portions extending between said upper and lower ch rds, continuously progressively straightening a pair of rods of indefinite length, continuously progressively forming alternately oppositely directed, spaced bends in a rod of indefinite length, leading said three rods into a guide with said pair of rods in engagement with opposite sides of said bent rod at one set of said bends, progressively transversely bending each of a pair of sheet metal strips of indefinite length to forni an angular member having an upstanding tiange and a horizontal flange connected by a bend, said bends being oliset to form a bead on each of said angular members projecting laterally from said upstanding flange in an opposite direction to said horizontal flange, feeding said pair of resulting continuous angular members with the upstanding ilanges thereof in engagement with the opposite sides of said bent rods at the other set'of bends therein and the crests of said beads in engagement with each other, progressively welding said beads to each other at their crests by a continuous resistance weld and said straight rods and said upstanding llanges to said bent rods as said rods and angular members are advanced,

d and shearing the resulting continuous welded member into desired lengths.

4. In the process of a structural member having an upper chord comprising a pair of rods, a lower chord comprising a pair or angular members and a web portion comprising a rod having oppositely inclined obliquely extending portions extending between said upper and lower chords, continuously progressively straightening a pair or rods of indefinite length, continuously progressively forming alternately oppositely directed, spaced bends in a rod of indenite length, leading said three rods into a guide with said pair of rods in engagement with opposite sides of said bent rod at one set of said bends, progressively transversely bending each of a pair of sheet metal strips of indefinite length to form an angular member having an upstanding flange and a horizontal flange connected by a bend, said bends being offset to form a bead on each or said angular members projecting laterally from said upstanding harige in an opposite direction to said horizontal flange and an inclined portion extending between said bead and upstanding leg, feeding said pair of resulting continuous angular members with the 11p-standing flanges thereof in engagement with the opposite sides of said bent rods at the other set of bends therein and the crests of said beads in engagement with each other, progressively welding said beads to each other at their crests by a continuous resistance weld with said inclined portions positioned to form a V-shaped trough above said continuous weld between said angular members and said straight rods and said upstanding anges to said bent rods as said rods and angular members are advanced, shearing the resulting continuous Welded member into desired lengths and supplying a sealing coating to said V-shaped groove.

References Sited in the le of this patent UNITED STATES PATENTS

Claims (1)

1. IN THE PROCESS OF MAKING A STRUCTURAL MEMBER HAVING AN UPPER CHORD COMPRISING A PAIR OF RODS, A LOWER CHORD COMPRISING A PAIR OF ANGULAR MEMBERS AND A WEB PORTION COMPRISING A ROD HAVING OPPOSITELY INCLINED OBLIQUELY EXTENDING PORTIONS EXTENDING BETWEEN SAID UPPER AND LOWER CHORDS, CONTINUOUSLY PROGRESSIVELY STRAIGHTENING A PAIR OF RODS OF INDEFINITE LENGTH, CONTINUOUSLY PROGRESSIVELY FORMING ALTERNATELY OPPOSITELY DIRECTED, SPACED BENDS IN A ROD OF INDEFINITE LENGTH, LEADING SAID THREE RODS INTO A GUIDE WITH SAID PAIR OF RODS IN ENGAGEMENT WITH OPPOSITE SIDES OF SAID BEND ROD AT ONE SET OF SAID BENDS, PROGRESSIVELY TRANSVERSELY BENDING EACH OF A PAIR OF SHEET METAL STRIPS OF INDEFINITE LENGTH TO FORM AN ANGULAR MEMBER HAVING AN UPSTANDING FLANGE AND A HORIZONTAL FLANGE CONNECTED BY A BEND, SAID BENDS BEING OFFSET TO FORM A BEND ON EACH OF SAID ANGULAR MEMBERS PROJECTING LATERALLY FROM SAID UPSTANDING FLANGE IN AN OPPOSITE DIRECTION TO SAID HORIZONTAL FLANGE, FEEDING SAID PAIR OF RESULTING CONTINUOUS ANGULAR MEMBERS WITH THE UPSTANDING FLANGES THEREOF IN ENGAGEMENT WITH THE OPPOSITE SIDES OF SAID BENT RODS AT THE OTHER SET OF BENDS THEREIN AND THE CRESTS OF SAID BEADS IN ENGAGEMENT WITH EACH OTHER, PROGRESSIVELY WELDING SAID STRAIGHT RODS AND SAID UPSTANDING FLANGES TO SAID BENT RODS AND SAID BEADS TO EACH OTHER AS SAID RODS AND ANGULAR MEMBERS ARE ADVANCED, AND SHEARING THE RESULTING CONTINUOUS WELDED MEMBER INTO DESIRED LENGTHS.

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