US3537224A

US3537224A - Truss joist with case-connected web members

Info

Publication number: US3537224A
Application number: US761234A
Authority: US
Inventors: Arthur L Troutner
Original assignee: Individual
Current assignee: Individual
Priority date: 1968-09-20
Filing date: 1968-09-20
Publication date: 1970-11-03
Anticipated expiration: 1987-11-03

Description

1,970 A. TROUTNER 3,537,224

V TRUSS JOIST WITH CASECONNECTED WEB MEMBERS I Filed Sept. 20, 1968 v "FIG.

IO FIG. 4

ARTHUR l TROUTNER INVENTOR.

IIIIH BY Zla hd ATTY.

FIG. .5 3634 United States Patent Olfice 3,537,224 Patented Nov. 3, 1970 3,537,224 TRUSS J OIST WITH CASE-CONNECTED WEB MEMBERS Arthur L. Troutner, Skyline Drive, Boise, Idaho 83702 Filed Sept. 20, 1968, Ser. No. 761,234 Int. Cl. E04c 3/292 U.S. Cl. 52-693 9 Claims ABSTRACT OF THE DISCLOSURE A truss joist comprises upper and lower chords having staggered recesses in their opposed faces. A plurality of structural cases are secured one in each of the recesses. A plurality of web members are arranged diagonally between the chords with the ends of adjacent web members overlapped, one pair of overlapped ends being inserted into each case. Securing means secure the web member ends to the respective cases, thereby interlocking the truss joist components.

This invention relates to truss joists of the class employed for supporting floors, roofs and other structural components.

One popular form of truss joist comprises wooden upper and lower chords having staggered slots in their opposed faces, and cross bores intercepting the slots. Web members or links are arranged diagonally between the chords.

The web members have perforated ends which are overlapped and inserted, one pair of overlapped ends in each slot, with the perforations in the web members ends being aligned with each other and with the cross bores of the slots. Pins then are pressed through the aligned openings to interlock the elements of the truss joist at the panel points and assemble the final product.

A truss joist of the foregoing class is subject to a certain disadvantage in that the provision of the cross bores which intercept the recesses and contain the pins removes some of the net section of the wood. This detracts from the efficiency of the truss. Also, the cross bores present points of weakness which makes the truss subject to splitting during manufacture, transportation or installation.

It accordingly is the purpose of the present invention to provide a truss joist having chords which are not cross bored and which accordingly works with greater efiiciency and is relatively free from a splitting tendency at its panel points.

It is a further object of the invention to provide a truss joist of well balanced construction and great efiiciency.

It is a further object of the present invention to provide a truss joist which has planar sides, free from outwardly projecting fastening members.

Still another object of the present invention is the provision of a truss joist, the components of which are securely interlocked.

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 truss joist with case-connected web members of the invention;

FIG. 2 is an exploded, fragmentary perspective view illustrating the construction and manner of assembly of one of the panel points of the truss joist;

FIGS. 3 and 4 are transverse sectional views taken along lines 33 of FIG. 1 and 44 of FIG. 3, respectively, further illustrating the construction of the panel points of the truss joist; and

FIG. 5 is a plan view, looking in the direction of the arrows of line 5-5 of FIG. 4.

In its broad aspect, the presently described truss joist comprises upper and lower chords having staggered recesses in their opposed faces. A structural case is inserted in each recess. A plurality of web members (links) are arranged diagonally between the chords, with the ends of each pair of adjacent web members being overlapped and extending into one of the cases. Suitable securing means secure each case to the chord in which it is contained.

The web members thus are connected to the chords by an internal connection which does not weaken the chord unnecessarily and which does not interrupt the planar side faces of the truss with outwardly projecting connecting members.

As shown in FIG. 1, the herein described truss joist comprises an upper chord 10 and a lower chord 12. The opposite faces of each chord are provided with staggered recesses 14 which in the illustrated form of the invention extend completely through the chord, from top to bottom.

The chords may be fabricated from wood pieces such as 2 x 4s, 2 x 3s, small glue-lam beams, etc.

The recesses in the chords are in staggered relation to each other, top and bottom. The chords are interconnected by a plurality of web members or links 16. These may be comprised of tubular steel members having fiattened ends 18. Suitably dimensioned and located transverse perforations 20 penetrate each of the web member ends.

In the construction of the truss joist, the links are arranged diagonally with adjacent flat ends overlapped. Means then are provided for connecting them to the chords. The means employed for this purpose are illustrated particularly in FIGS. 2-5 inclusive.

Basically considered, the means by which the web members are connected to the chords comprises a structural case, i.e. a case of rigid metal having appreciable strength inserted in each of the chord recesses, secured thereto, and connected to the web members.

In the illustrated form of the invention, each case is indicated generally at 22. It comprises two interlocking

parts

24, 26 respectively. When interlocked, they form a unit which may be pressed into one of recesses 14.

Both parts may be stamped out of heavy gauge sheet metal using dies of suitable design.

Case component 24 includes a side wall 28 having a central, integrally formed short sleeve 30 therethrough. A pair of inwardly bent end plates 32 extend substantially normally to the plane of the side wall. A flange or foot 34 extends outwardly from the bottom of the side wall, substantially normal to its plane.

Case component 26 comprises a side wall 36 having an integrally formed short sleeve 38 centrally thereof (aligned with short sleeve 30), a pair of end plates 40', a plurality of short ribs 42 adjacent its side margins, and a flange or foot 44 extending outwardly from its lower margin, substantially at right angles.

End plates 40 of one part overlap end plates 32 of the companion part. They are provided with upward extensions 40a which may be bent outwardly at right angles to the position of FIG. 4.

Case components

24, 26 may be nested together in the position of FIGS. 3, 4 and 5 to form a strong case. In their nested position, end walls 32 of case component 24 are protected from buckling by overlapped end wall plates 40 of case component 26.

End plates 40, not being thus protected, are rigidified against buckling by integral ribs 42.

In assembling the truss joist, the perforated ends of the end links are overlapped and

case segments

24, 26 nested together over the web member ends in the manner shown in FIG. 2. In this position of the assembly, perforations 20 through the ends of the web members are aligned with

short sleeves

30, 38 of the case components. A short pin 48 then is pressed through the aligned openings to interlock the assembly. It is retained in position by the frictional forces generated between the pin and

short sleeves

30, 38.

With tabs 40a extending upwardly, the assembly is inserted into the selected one of recesses 14 in the chord members of the truss. After being so inserted, tabs 40a are lbent outwardly.

This procedure is repeated along the length of the truss joist until the latter has been assembled completely.

The final truss joist has a balanced construction which causes it to function with a high degree of efliciency. The web members transmit the stresses to inner pins 48 which transmit them through the case to the chord. Both vertical and horizontal forces are thus transmitted.

While top tabs 40a retain the components in their assembled condition during assembly of the truss, foot flanges 44 contain the vertical loads on the truss. Ribs 42 prevent collapse of end plates 40 during the application of load. Tabs 40a support the ceiling loads. The stresses thus are distributed by the case so that relatively light weight trusses may be used for comparatively heavy duty applications.

The efliciency of the herein described truss joint is evident from the following comparison of a conventional truss joist and, the truss joist of the invention.

The conventional truss joist consisted of wooden chords slotted and cross drilled in the manner described above. The case-connected truss joist consisted of the elements described herein, the wooden members being of the same dimensions as in the case of the conventional truss joist. The results of the tests were as follows:

Conven- Case contional nected truss truss Percentage joist joist increase Net wood section (in.*) 2. 843 3. 937 +37 Bearing (pounds) 780 937 +20 Bearing I (pounds) 2,500 2,875 +11.5 Pin link tension (pounds) 2, 862 3, 590 +25 It thus is readily apparent that by the present invention (b) a plurality of structural cases secured one in each recess,

(0) a plurality of web members arranged diagonally between the chords with the ends of adjacent web members overlapped, one pair in each case, and

(d) securing means confined within the recess securing the overlapped ends of the web members in the case.

2. The truss joist of claim 1 wherein the overlapped I ends of the web members are perforated and the side walls of the case have transverse openings aligned with the web member perforations and each other, and wherein the securing means comprises pin means pressed into the aligned openings and perforations.

3. The truss joist of claim 1 wherein each case comprises a pair of side plates, each side plate having integral, inwardly bent and plates, the end plates of one side plate nesting within the end plates of the other, the overlapped web member ends being provided with registering perforations, the side plates being provided with centrally located short sleeves registering with the perforations and with each other, and wherein the securing means comprises pin means pressed through the perforations and short sleeves, thereby mounting the web member ends in the case and contemporaneously holding together the case parts.

4. The truss joist of claim 1 wherein each case comprises a pair of side plates, each side plate having a pair of inwardly directed end plates, the end plates on one side plate nesting within the end plates of the other side plate, the end plates of one side plate extending upwardly beyond the plane of the case and of the chord in which it is received, the end plate ends thus projecting being bent outwardly to engage the chord and retain the case in the recess therein.

5. The truss joist of claim 4 wherein the overlapped end plates are the ones provided with extensions and wherein the side plate supporting the overlapped plates is provided with a plurality of short ribs adjacent the end plates to prevent its buckling under load.

6. The truss joist of claim 1 wherein the case comprises a pair of nesting interengaged parts, each part having along its lower margin anoutwardly extending flange designed to engage the underside of the chord adjacent the recess in which the case is received.

7. A truss joist comprising (a) upperand lower wood chords having staggered recesses in their opposed faces,

(b) a plurality of structural cases secured one in each recess and comprising a pair of side plates, each side plate having integral, inwardly bent end plates, the end plates of one side plate nesting within the end plate of the other, the side plates being provided with centrally located short sleeves,

(c) a plurality of web members arranged diagonally between the chords with the ends of adjacent web members overlapped, one pair in each case, the overlapped web member ends being provided with registering perforations registering with the short sleeves, and

(d) securing means securing the overlapped ends of the web members to the case and comprising pin means pressed through the perforations and short sleeves, thereby mounting the web member ends in the case and contemporaneously holding together the case parts.

8. A truss joist comprising (a) upper and lower wood chords having staggered recesses in their opposed faces,

(b) a plurality of structural cases secured one in each recess and each comprising a pair of side plates, each side plate having a pair of inwardly directed end plates, the end plates on one side plate nesting within the end plates of the other side plate, the end plates of one side plate extending upwardly beyond the plane of the case and of the chord in which it is re- 5 ceived, the end plate ends thus projecting being bent outwardly to engage the chord and retain the case in the recess therein,

(c) a plurality of web members arranged diagonally between the chords With the ends of adjacent web members overlapped, one pair in each case and (d) securing means securing the overlapped ends of the web members to the case.

9. The truss joist of claim 8 wherein the overlapped end plates are the ones provided with extensions and wherein the side plate supporting the overlapped plates is provided with a plurality of short ribs adjacent the end plates to prevent its buckling under load.

6 References Cited UNITED STATES PATENTS 10/ 1963 Abramson 52-694 X 11/ 1963 Smith 287--20.92

FOREIGN PATENTS 8/ 1966 Canada.

PRICE C. FAW, JR., Primary Examiner US. Cl. X.R.