US3496693A

US3496693A - Stapled composite truss joist and method of assembly

Info

Publication number: US3496693A
Application number: US761751A
Authority: US
Inventors: Arthur L Troutner
Original assignee: Individual
Current assignee: Individual
Priority date: 1968-09-23
Filing date: 1968-09-23
Publication date: 1970-02-24
Anticipated expiration: 1987-02-24

Description

Feb. 24,1970 A. L. TROUTNER STAPLED COMPOSITE'TRUSS JOIS'I' AND METHOD OF ASSEMBLY Filed Sept. 23, 1968 ARTHUR L. TROUTNER INVENTOR BY 5 ATTY.

United States Patent 3,496,693 STAPLED COMPOSITE TRUSS JOIST AND METHOD OF ASSEMBLY Arthur L. Troutner, Skyline Drive, Boise, Idaho 83702 Filed Sept. 23, 1968, Ser. No. 761,751 Int. Cl. E04c 3/09 US. Cl. 52-693 3 Claims ABSTRACT OF THE DISCLOSURE A structural truss joist for use in supporting roofs, floors, etc. includes two vertically spaced chords dimensioned to span two horizontally spaced bearing walls. Each chord comprises two spaced lumber pieces placed side by side parallel to each other. A plurality of metal links are arranged zigzag between the chords. The ends of adjacent links overlap and extend between the lumber pieces comprising the chords. Registering openings extend through the pieces and each pair of overlapped link ends. Unsecured metal pins penetrate the registering openings. Staples interconnect the lumber pieces comprising each chord, holding the pieces together, spacing them the proper distance apart, and stabilizing the chords from buckling under compressive loads.

This invention relates to truss joists designed to carry heavy loads and to span substantial distances.

In my US. Patent No. 3,330,087 there is disclosed a heavy duty truss joist of the class comprising upper and lower chords interconnected by webbing of metal links arranged zig-zag between the chords. Each chord is a composite of two parallel pieces spaced laterally from each other. The ends of each pair of adjacent links are overlapped, inserted in the space between the pieces comprising the chord, and fastened to each other and to the pieces by pins penetrating registering opening through all of these members. Securing means such as press on washers secure the pins, preventing them from becoming dislodged.

The foregoing tr-uss joist assembled is of great strength and has major applications. However, it is the purpose of the present invention to provide a truss joist of the class described, but having materially improved characteristics and functions, as follows:

(1) It maintains an accurate spacing between the pieces comprising the respective chords.

(2) It holds'the pieces together securely.

(3) It eliminates the securing washers or other externally projecting fasteners for securing the pins to the chords. This in turn makes possible the provision of truss joists having flush side faces, without projecting metal parts.

(4) It includes chords which are stabilized from buckling under compressive loads.

(5) It may include chords composited from lumber pieces of smaller size and lower grade without sacrifice of truss joist properties, thereby decreasing the cost of the final product.

(6) It maybe made lighter, without sacrifice of strength, thereby facilitating and rendering less expensive its handling, transportation and application to various construction projects.

(7) Its assembly at the plant is greatly simplified, increasing production and reducing labor costs.

The manner in which the foregoing and other objects of the invention are accomplished will be apparent from the accompanying specification and claims considered together with the drawings, wherein:

FIG. 1 is a fragmentary view in side elevation of the herein described stapled, composite truss joist;

3,496,693 Patented Feb. 24, 1970 FIGS. 2, 3 and 4 are fragmentary sectional views taken along lines 2, 3 and 4 respectively of FIG. 1; and

FIG. 5 is a view in elevation of a staple element employed in the construction of the truss joist illustrated in the preceding figures.

Generally stated, the stapled, composite truss joist of my invention comprises a structural truss joist for use in supporting roofs, floors, etc. It includes two vertically spaced chords dimensioned to span two horizontally spaced bearing walls. Each chord comprises two spaced lumber pieces placed side by side parallel to each other.

A plurality of metal links are arranged zig-zag between; the chords, with the ends of adjacent links overlapped and extending between the lumber pieces comprising the chords. Registering openings extend through the pieces and each pair of overlapped link ends. Unsecured metal pins penetrate the registering openings.

Staples interconnect the lumber pieces comprising each chord, holding the pieces together, spacing them the proper distance apart, and stabilizing the chords from buckling under compressive loads.

Considering the foregoing in greater detail and with particular reference to the drawings:

As indicated in FIG. 1, the stapled, composite truss joists of my invention are supported in parallel, spaced arrangement between a pair of bearing walls, one of which is indicated at 4. The bearing walls may be of wood, concrete, or masonry construction. A wooden or other bearing plate 6 may lie across the top of each bearing wall.

Each joist is composed of an upper chord, indicated generally at 10, and a lower chord, indicated generally at 12. In one embodiment, upper chord 10 is longer than lower chord 12. Its ends overlie and are supported bv the bearing plate.

Lower chord 12 is slightly shorter than the distance between the bearing walls 4 spanned by the joists. It is not supported directly thereby, but is nailed or otherwise fastened to a stabilizing strip 14 mounted on the inside surface of the bearing Walls.

To supply the requisite strength and length, while using a minimum of lumber, each of chords 10, 12 is a composite of two structural pieces placed side by side, parallel to each other, and spaced apart horizontally to provide an intermediate space of predetermined width, as required to accommodate linking members.

Thus, in the case of a medium high-load truss joist, each chord may be a composite of a pair of 2 x 3 pieces placed on edge; the pieces comprising upper chord 10 are indicated at 15, 16. Lower chord 12 may be constituted similarly.

Upper chord 10 and lower chord 12'are interconnected by a lacing of link members arranged zig-zag with their ends overlapped. Each link member may comprise a metal tube 20 having transversely perforated flat ends 22. The latter are of such thickness that when overlapped they may be inserted in the space between the pieces comprising each chord as shown particularly in FIGS. 2 and 3.

At spaced offset intervals, which may be longer and farther apart than the intervals of the truss joist of my US. Patent No. 3,330,087 aforesaid, the upper and lower chords are cross bored to form openings which register with the perforations through the flattened ends 22 of the link members.

Pin means are inserted through the registering Openings to interconnect the link members and the chords. The construction of the pin means employed is illustrated particularly in FIG. 3.

As illustrated in that figure, each pin means may comprise a hollow cylinder 24 dimensioned for snugly fitting reception in the registering cross bores through the lumber pieces and the perforations through the flat link ends.

3 The ends of the cylinders lie flush, or are slightly recessed in, the exterior side faces of the chord.'They do not project outwardly. Beyond the frictional engagement supplied by the snug fit, no extraneous fasteners secure the pins to the lumber pieces and links. In other words, the ins are unsecured in their respective chord-link assemblies.

The key feature of the herein described composite truss joist, and that which distinguishes them in structure and properties from the truss joist of the prior art, is the provision of a plurality of staples 30 which are driven into the pairs of lumber pieces comprising each chord. The staples interconnect the pieces and maintain them separated by a spaced distance.

As illustrated in FIG. 5, the staples are of the heavy duty structural class designed to carry a substantial load. To fix them securely in piace, their terminal portions preferably are serrated. The weight and dimensions of the staples may be varied to suit particular applications.

However, where 2x35 are employed as the lumber pieces comprising the chord, the staples may comprise 1% inch heavy duty metal staples.

Similarly, the spacing of the staples from each other may be varied to suit the particular properties demanded of the final product. However, in a typical product, the staples may be placed on the top and bottom of the chords opposite each other, on each side of each panel point. This arrangement is shown particularly in FIG. 1.

The stapled truss joists of my invention are easily manufactured. First, the lumber pieces making up the chords are positioned with the predetermined lateral spacing in a suitable jig or holder. Next, the staples are driven into 'the pieces at the desired locations, maintaining the spacing. Next the connecting web .of links is inserted into the spaces thus provided, aligned, and the pins driven through the resulting assembly. This completes the manufacture of the truss joist.

Manifold benefits flow from the application of the product and method described above. The truss joists are stabilized against buckling under compressive loads by the presence of the staples so that desired ratings are maintained using lighter weight chords of lower grade lumber. The individual links are locked in by the wood 1. A composite truss joist comprising "(a) two 'vertically spaced chords/dimensioned to span two horizontally spaced bearing walls,

(bf: each chord comprising two juxtaposed lumber pieces placed side by side and parallel to each other,

(c) a plurality of links arranged in zig-zag relation between the chords with the ends of adjacent links overlapped and extending between the lumber pieces comprising the chord,

(d) there being registering openings through the pieces and each pair of overlapped link ends,

(e) unsecured metal pin means penetrating the registering openings, securing together the links and pieces, forming panel points,

(f) and staple means driven into the pieces comprising each chord at spaced intervals, on each side of each panel point, thereby maintaining the pieces in their spaced apart relation, maintaining the overlapped links and pins in their assembled condition, and stabilizing the chords from buckling under compressive loads.

2. The truss joist of claim 1 wherein the staples are spaced substantially opposite each other, top and bottom of the chords, one pair on each side of each panel point.

3. The method of compositing a structural truss joist which comprises (a) positioning a pair-of lumber pieces in laterally spaced relation to each other.

(b) stapling the pieces together while maintaining the spaced relation between them, thereby producing a composite chord,

(c) arranging two of the composite chords in spaced apart upper and lower chord relation;

((1) arranging interconnecting links zig-zag between the chords with the ends of adjacent ones of the links overlapped and inserted in the space between the pieces comprising each chord,

(e) the link ends and adjacent chord areas having registered openings therethrough, and

(f) inserting pins through the registering openings,

thereby assembling the composite truss joist.

References Cited UNETED STATES PATENTS JOHN E. MURTAGH, Primary Examiner U.S. Cl. X.R. 29-155, 432, 526