US3313082A

US3313082A - Truss system and method of erecting

Info

Publication number: US3313082A
Application number: US364733A
Authority: US
Inventors: Carl H Seaborg; Robert M Dodds
Original assignee: Republic Steel Corp
Current assignee: Republic Steel Corp
Priority date: 1964-05-04
Filing date: 1964-05-04
Publication date: 1967-04-11
Anticipated expiration: 1984-04-11

Description

P 11, 1967 c. H. SEABORG ETAL 3,313,082

TRUSS SYSTEM AND METHOD OF ERECTING 5 Sheets-Sheet 1 Filed May 4, 1964 FIG. 4.

ZNVENTORS CARL H.5EABOR 1 RQBERT M; DoDDs ATTORNEY April c. H SE ABORG ETAL 3,

TRUSS SYSTEM AND METHOD OF EREC TING Filed May 4, 1964 5 Sheets-Sheet 2 FIG. 6.,

INVENTORS CARL H. SEABORG ROBERT M. DODDS BY M WW' ATTORNEY p 1967 c. H. SEABORG ETAL I 3,313,082

TRUSS SYSTEM AND METHOD OF ERECTING Filed May 4, 1964 5 Sheets-Sheet 5 FIG. 11.

IF!-' I 4 45 l :1 I In 52 52 INVENTORS CARL H. SEABORG ROBERT MJDODDS ATTORNEY United States Patent Cfitice 3,313,982 Patented Apr. 11, 1967 3,313,082 TRUSS SYSTEM AND METHGD F ERECTING Carl H. Seaborg, Youngstown, Oh o, and Robert M.

Dodds, Pittsburgh, Pa., assignors to Republic Steel Corporation, Cieveland, Ohio, a corporation of New Jersey Filed May 4, 1964, Ser. No. 354,733 11 Claims. (Cl. 53-646) This invention relates to metal structural elements for use in buildnig construction and other types of metal construction, as Well as to a method. of assembling the elements.

More particularly, this invention relates to a metal truss system including longitudinal members and separately formed diagonal members especially adapted for use in the construction of roofs and floors.

The basic component in the present invention comprises a single upper chord and a single lower chord attached to one another by means of a web section. These members are subsequently connected to one another in adjacent relationship so that juxtaposed upper and lower chord members are secured to one another to provide a plurality of truss members, an end section of which is delta-shaped. In such a delta-shaped truss system the attachment of adjoining top chords provides an exceptionally stable system as each of the top chords obtains stability from its companion chord. In such a construction, the overall height of the assembly is reduced since less material is needed as compared with previous triangular trusses whcih required considerably more material in order to be structurally self-sufficient.

In present known truss elements, such as the individual triangular types, the cost of ship-ping and installing is very high since each of the trusses takes up considerable space during shipping and must be handled as an individual unit during the installation stage. In the present invention, many advantages are realized by utilizing a truss member which may be assembled and bundled by the manufacturer in a collapsed position so that it may be shipped in as compact a manner as possible. This same arrangement permits a method for quickly installing the preassem'bled trusses on location with minimum cost, as the entire truss system for one level, for example, in the construction of a floor of a building, may be lifted into position upon the building supporting members and expanded in accordion manner to its final installed position.

Accordingly, one of the objects of the present invention is to provide a new type of metal truss element which will lend itself to a unique type of ceiling, floor, or roof construction.

Another object of this invention is to provide a delta truss system comprising a plurality of similarly constructed truss elements having their adjacent upper and lower chord members connected in hinged relationship to permit collapse and expansion of the truss assembly.

Still another object of the invention is to provide a delta truss system including upper chord members provided with novel means for reducing friction during the placement of the system into position upon suitable supporting means.

A further object of the present invention is to provide a truss system comprising a plurality of metal truss members having adjacent upper and lower chords attached to one another by means of novel hinge arrangements.

A still further object of the present invention is to provide a delta truss system having upper chord members which also serve as hinge means for adjustably connecting adjacent truss elements.

Another object of the invention is to provide a method of erecting a metal truss system whereby a complete assembly for a floor or other structure is placed in position in a compacted status and thereafter expanded accordion-style to its final arrangement.

With these and other objects in view which will more readily appear as the nature of the invention is better understood, the invention consists in the novel construction, combination and arrangement of parts hereinafter more fully described, illustrated and claimed.

A preferred and practical embodiment of the invention is shown in the accompanying drawings in which:

FIGURE 1 is a perspective view of a pair of truss elements according to the present invention.

FIGURE 2 is an end elevation of one of the truss elements shown in FIGURE 1.

FIGURE 3 is an end elevation of a plurality of the truss elements of FIGURE 2 arranged to provide a collapsed truss assembly as shipped and ready for installation.

FIGURE 4 is an end elevation partly in section and illustrates a delta truss arrangement according to the present invention.

FIGURE 5 is a partial end elevation and illustrates one form of hinge connection between adjacent upper chord members wherein the upper chord members form a part of the hinge structure.

FIGURE 6 is a partial end elevation of another embodiment of a hinge structure.

FIGURE 7 is a partial side elevation of a truss assembly as positioned on a supporting beam and having a sheet metal deck mounted thereon.

FIGURE 8 is an end elevation partly in section of a delta truss system having reinforcing struts connecting adjacent bottom chord members and a cast-in-situ concrete floor on the upper chord members.

FIGURE 9 is an enlarged partial end elevation illustrating a modified upper chord and hinge arrangement including bearing shoe members for supporting the upper chord members on a supporting beam.

FIGURE 10 is a partial side elevation of the structure shown in FIGURE 9.

FIGURE 11 is a partial end elecation illustrating the elements of FIGURE 9 as they appear with the truss assembly in a collapsed position while resting on a supporting beam prior to expansion to the final installed position as shown in FIGURE 9.

FIGURES l2 and 13 are partial end elevation views disclosing further modifications of upper chord members forming hinge connections between adjacent truss elements.

Similar reference characters designate corresponding parts throughout the several views of the drawings.

The general arrangement of a delta-shaped metal truss, as shown in FIGURE 1, is not new in itself; however, in the present instance improved truss elements have been developed to permit construction of a stronger and more readily installed truss system.

FIGURE 2 illustrates the basic truss element construction used throughout the several embodiments of the present invention and discloses an upper chord-member 1 and lower chord member 2 joined to one another by means of a suitable web assembly 3 which may be welded to the chords or secured by other appropriate means. Both the chord members 1 and 2 and the web assembly 3 may be of any suitable cross-sectional shape. One form for the chord members is that of angular bars, as illustrated, While each web element 3 may comprise either an undulating Web member such as shown in FIGURE 7, or a plurality of individual diagonal braces such as shown in FIGURE 1. In either case, the web elements may be of various crosssections, for example, round, square, oblong, or channels-haped bars, angles, or tubes or may be of any other light structural section.

In forming a truss system utilizing the truss element shown in FIGURE 2, it will be understood that a plurality of the elements generally designated A are assembled in adjacent juxtaposed relationship in order to achieve a continuous delta shaped truss system such as shown in FIGURES 4 and 8. Suitable conventional means, such as welding, is employed to secure the adjacent chords of the assembly together to provide a rigid truss system. Quite obviously, however, any method of assembly which would require the handling and placement of a plurality of separate truss elements A at the installation site would involve both an excessive amount of time and expense.

Accordingly, it is proposed to provide hinge means for pivotally connecting the adjacent upper and lower chord members of a plurality of truss elements prior to erection of the system. This obviates the necessity of providing for assembling or attaching a plurality of individual truss members A to one another at the time of installation, and leads to an inexpensive and rapid method of installing an entire delta-truss system in a building construction. The system is subsequently strengthened by welding adjacent chords.

FIGURES 3 and 4 disclose one form of hinge connecting means H comprising a pair of butts 4 and 5 which are attached, for example, by welding to the opposed edges 6 and 7 of two adjacent top chord members 1. A pintle 8 pivotally connects the butts 4 and 5. It will be understood that not only are all of the alternate pairs of upper chords 1 provided with similar pivotal connection means, but also each alternate pair of adjacent lower chord members 2 are similarly provided with identical connection means. Thus, it will be seen that the truss system when initially assembled by the manufacturer may be shipped to the site of construction in the collapsed manner illustrated in FIGURE 3. When it is desired to install the truss system, a crane can then pick up the collapsed structure, such as shown in FIGURE 3, and position it with the free or extending ends 9 and 10 of the upper chords resting upon suitable transverse supporting beams S. The truss assembly is then expanded accordionstyle by pulling apart the two outermost upper chord members 1 until all the truss members A are spread apart to their fully-opened position. This may be deemed as the point at which the upper chord members can no longer be pivoted around the pintle 8 of the hinge means H. The butts 4 and 5 are formed such that when they are attached to the flanges 6 and 7 of the upper chord members they will be fully closed in the position shown in FIGURE 4 in which case the flanges 6 and 7 will be perpendicular to the supporting means S, with the result that the other

adjacent flanges

11 and 12 forming the chords will be disposed in a near-perfect horizontal position ready for reception of any suitable flooring structure thereupon.

FIGURE 5 discloses another embodiment of the hinge means for connecting alternately adjacent upper and lower chord members. In this form the chord members, generally designated 13 and 14, are also formed in such a manner as to include a portion of the hinge structure. The outer edge 15 of the chord member 14 is secured to the upper portions of the web 16 by any suitable means and is bent to form the supporting surface 17 which is designed to be horizontally disposed when the truss assembly is in its final installed position. At the other edge of the supporting surface 17, the chord member 14 is bent to form a recess 18. Adjacent to this recess a leg 19 of the chord member engages the upper ends of the web members 16 on the side opposite that to which the outer edge 15 of the chord member is attached. The chord member is then doubled back upon itself to form a pivot section 20 having a free hook portion 21 projecting towards the recess 18.

A pair of truss sections each provided with upper chord members as above described are placed in opposed relationship with the pivot sections 20 abutting one another as in FIGURE 5. A spring clip 22 having inwardly curved engagement arms 23 is placed over the pair of outwardly projecting hook portions 21 of the

chord members

13 and 14 and thereby retains the two adjacent truss elements together by means of its resilient biasing action which urges the two portions 2t) together under constant tension regardless of the relative angular displacement of the two truss elements.

Also, as previously described in reference to the connection means of FIGURE 3, it will be understood that similar hinge means are utilized in this embodiment to connect alternate adjacent lower chord members together so that the present invention may be practiced in erecting an entire floor or level at one time.

FIGURE 6 illustrates another form of connecting means whereby a single unitary member 24 not only serves as two adjacent chord members, but also includes hinge means permitting relative movement between adjacent truss elements. In this form, the unitary hinge members 24 includes two symmetrical sections, each including outer and inner web-engaging edges 25, 26, respectively, attached to the upper or lower portions of the web elements 16, Whichever the case may be. A top 27 and side surface 28 joins each outer edge 25 to its respective inner edge 26. Bridging the gap between the two inner edges 26, 26 is a plastic-hinge section 29 including a reduced area portion 30 medially disposed longitudinally therein.

It is believed that the operation of this embodiment will be readily apparent, as the inherent plastic nature of the reduced portion 30 permits contraction and expansion of a plurality of so-equipped tnuss elements. By forming the

surfaces

27 and 28 perpendicular to one another, it will be seen that when the truss assembly is expanded as in FIGURE 6, the adjacent side surfaces 28, 28 will abut each other to limit the expansion of the truss elements and present the

top surfaces

27, 27 in a horizontal plane for the reception of suitable flooring structure.

The hinge connecting means disclosed in the embodirnent illustrated in FIGURE 13 comprises symmetrical

upper chord members

31 and 32, connected to each other by means of a hinge assembly 33 having a pair of

butts

34 and 35, each secured to a leg of one of said chord members and pivotally retained together by means of a pintle 36. The upper surfaces 37 and 38 of the

chord members

31 and 32 are preferably disposed at right angles to the side surfaces 39 and 40, similar to the arrangement of the surfaces of the chord members in the embodiment illustrated in FIGURE 6 so that when a truss assembly comprising a plurality of similarly connected elements is expanded upon the supporting beams S during installation, the hinge connecting means will appear as in FIGURE 13 wherein it will be seen that the truss web elements 16 when fully expanded will be limited in their angular displacement due to the flush abutment of the side surfaces 39 and 40. Also, when the truss elements are properly expanded, the

top surfaces

37 and 38 will be horizontally disposed for reception of appropriate subsequent flooring structure.

FIGURES 9-11 relate to still another form of upper chord members, generally designated 41 and 42. In this instance, each chord member comprises a strip of metal having a single curve providing a short offset

portion

43 and 44, which is disposed at an acute angle with respect to the

main body portion

45, 46. Hinge connecting means between adjacent alternate pairs of upper and lower chord members is provided by means of a plurality of oppositely disposed overlapping tabs 47, each of which is provided with an axial bore for the reception of suitable pivotal fastening means, such as screw-threaded bolts 48. The angle of the short offset

portions

43, 44 of the chords is such that when the truss elements generally designated 49 are fully expanded, the upper surface of these portions will be horizontally disposed for reasons made obvious hereinbefore. It will be seen that the abutment of the opposed

curved sections

50 and 51 limits the expansion of the truss elements 49 during installation.

Another feature disclosed in connection with this embodiment, but which may be utilized with any of the disclosed forms of the invention, includes a bearing shoe 52 fastened by any suitable means to the ends of each of the upper chord members. As will be most clearly seen in FIGURE 10, one bearing shoe i mounted at the end of each upper chord member and depends from the lower edge ofthe chord so as to rest upon the supporting beam S. An important feature is that the bearing shoes 52 are provided on their lower edge with a rounded or curved surface 53 as shown in FIGURES 9 and 11.

The object of the bearing shoe 52 will be readily appreciated by referring back to FIGURE 4 which discloses upper chord members resting upon a supporting beam S without the benefit of bearing shoes 52. It will be seen that when a collapsed truss assembly such as shown in FIGURE 3 is initially lowered onto a pair of spaced apart supporting beams S, the entire weight of the assembly will rest upon the sharp corners of the edges of the lower flanges 6 and 7 forming the upper chord members and as the truss assembly is expanded to the installed position, such as in FIGURE 4, a great amount of friction is created between these sharp edges and the top of the supporting beams S. This excessive friction would be evident throughout the entire period of expansion since it is not until the assembly is finally positioned, as in FIGURE 4, that the flanges 6 and 7 are resting squarely upon the top of the beams S. By providing one of the bearing shoes 52 on the end of each upper chord member so that the entire weight of the structure is transmitted through the rounded tip 53 of the shoes, it will be seen that the amount of friction is greatly reduced and thereby lessens the force or effort required to expand a truss assembly during installation.

FIGURE 7 discloses a truss assembly having upper and lower chord members 1 and 2, such as disclosed in FIG- URES 1-4, but shows a modified web construction comprising a continuous bar 3a. This figure also discloses a typical sub-flooring, for example, transversely installed metal decking 54, which may be utilized in connection with any of the forms of the invention.

The arrangement shown in FIGURE 8 comprises another modification of the present delta truss system, and includes additional transverse reinforcing means in the form of a plurality of strut members 55, bridging the lower chord members 2 to provide additional transverse rigidity. Also shown is a flooring structure which, in this instance, comprises a cast-in-situ concrete layer 56 poured around the upper chord members 1.

FIGURE 12 illustrates another modification of the hinge connecting means and discloses upper chord members 57 and 58, which also form the two leaf sections of a continuous piano-type hinge. It will be understood that the leaf sections 57 and 58 are inter-woven and encircle a common pintle 59 about which the chord-hinge members 57 and 58 pivot. Each one of a plurality of connecting sections 58a in the leaf 58 is disposed for limited angular movement through a cut-out portion 57a in the other leaf 57. The

end walls

57b and 57c of each of the cut-out portions 57a will be seen to .act as a stop or abutment to limit the opening and closing movement of the truss assemblies 60.

We claim:

1. A metallic structural assembly for suspension between a plurality of horizontal transversely disposed beams comprising: a plurality of rigid truss sub-assemblies, each of said sub-assemblies including, a parallel upper and lower chord disposed in offset vertical planes, said upper chord having an uppermost horizontal surface, a web rigidly connecting said upper and lower chords; means connecting together in juxtaposed relationship a pair of upper chords of two of said sub-assemblies to provide an inverted V-shaped assembly, whereby said upper chords are supported at their extremities upon a pair of said horizontal beams and said horizontal surfaces of said pair of upper chords are retained in one horizontal plane.

2. A metallic structural assembly for suspension between a plurality of horizontal transversely disposed beams comprising; a plurality of rigid truss sub-assemblies, each of said sub-assemblies including, a parallel upper and lower chord disposed in offset vertical planes, said upper chord having an uppermost horizontal surface, a web rigidly connecting said upper and lower chords; said sub-assemblies disposed in pairs having means connecting in juxtaposed relationship adjacent pairs of upper chords to provide a plurality of inverted V-shaped assemblies; and means connecting together in juxtaposed relationship adjacent pairs of said lower chords of alternate adjacent pairs of said sub-assemblies to provide a unitary truss assembly, whereby said upper chords are supported at their extremities upon a pair of said horizontal beams and said horizontal surfaces of said pair of upper chords are retained in one horizontal plane.

3. A metallic structural assembly according to claim 2, wherein, both of said connecting means joining said upper and lower chords of said sub-assemblies comprise hinge means permitting collapse and expansion of said unitary truss assembly.

4. A metallic structural assembly according to claim 3, wherein each of said hinge means comprises a pair of butts pivotally joined by a pintle.

5. A metallic structural assembly according to claim 3, wherein, each of said upper and lower chords includes a top and side surface disposed at right angles to one another, whereby when said structural assembly is expanded said side surfaces are vertically disposed.

6. A metallic structural assembly acording to claim 5, whereby when said structural assembly is expanded, each pair of opposed side surfaces are in abutment to limit the expansion of the assembly.

7. A metallic structural assembly according to claim 3, wherein each pair of adjacent upper and lower chords comprises a single unitary member and said hinge means includes a reduced thickness area intermediate said member providing a point between said pairs of chords and adapted to yield by deformation during collapse and expansion of said structural assembly.

8. A metallic structural assembly according to claim 3, wherein said hinge means includes a clip resiliently connecting said adjacent chords by a spring action constantly urging said chords into abutment with one another.

9. A metallic structural assembly according to claim 3, wherein each of said upper and lower chords comprises a main body portion connected to a short offset portion by a curved section, said offset portion disposed at an acute angle with respect to said main body portion, a plurality of tabs projecting at right angles from one side of said main body portions, said tabs on adjacent chords disposed in opposed and overlapping relationship, whereby when said assembly is expanded, said curved sections of adjacent chords abut one another and said offset portions are horizontally disposed.

10. A metallic structural assembly according to claim 3, wherein, each end of said upper chords disposed over said horizontal beams includes a bearing shoe secured thereto, said shoes depending from the lower edge of said upper chords over said supporting means, and a rounded portion on the lower edge of said shoes, whereby, as said unitary truss assembly is collapsed or expanded only said rounded portions contact said beams.

11. A method of erecting a metallic structural assembly upon a pair of spaced apart transverse supporting means, said assembly including a plurality of sub-assemblies each having an upper and lower chord connected by a web member, comprising the steps of; providing alternate adjacent upper and lower chords of said subassemblies with hinge-connecting means, elevating said assembly while collapsed in compact condition into posi- 7 a 9 tion with only the ends of said upper chords resting upon 2,687,102 8/ 1954 Rongved et a1. 52643 X said supporting means, and expanding the collapsed as- 2,855,617 10/ 1958 Broms et al. 52646 sembly by pulling apart the sub-assemblies whereby said 2,979,169 11/ 1961 Yolles 52650 alternate adjacent upper and lower chords pivot about 3,235,903 2/ 1966 Anderson 16167 said hinge connecting means. 5 FOREIGN PATENTS References Cited by the Examiner 635, 2 1 50 Great Britain.

UNITED STATES PATENTS HARRISON R. MOSELEY, Primary Examiner. 2,270,161 1/1942 Briggs 52-'64.3 X

2,461,916 2/1949 Omar 52641 X 10 A. I. BREIER, Assistant Examiner.