Search Images Maps Play YouTube News Gmail Drive More »
Sign in
Screen reader users: click this link for accessible mode. Accessible mode has the same essential features but works better with your reader.

Patents

  1. Advanced Patent Search
Publication numberUS3651612 A
Publication typeGrant
Publication dateMar 28, 1972
Filing dateNov 18, 1970
Priority dateNov 18, 1970
Publication numberUS 3651612 A, US 3651612A, US-A-3651612, US3651612 A, US3651612A
InventorsSchmitt Jack N
Original AssigneeTruswal Systems Inc
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Floor joist
US 3651612 A
Abstract
A truss-type floor joist formed of vertically aligned parallel chords connected together between their ends by alternating diagonal web members and at their ends by a pair of vertical end members arranged in face-to-face contact, with the chords, web members and end members all formed of 2x4 wood strips arranged with their narrow edges vertical. Each chord has an inner liner member in the form of a 2x4 wood strip member arranged in face-to-face contact therewith and extending from each end of the chord to a point just past its first, adjacent set of diagonal web members. Each of the joints formed by abutting web members and end members with the chords are overlapped on both vertical faces with metal connector plates having struck-out teeth embedded in the respective overlapped wood members.
Images(1)
Previous page
Next page
Claims  available in
Description  (OCR text may contain errors)

United States Patent Schmitt [451 Mar. 28, 1972 [s41 FLOOR JOIST Primary Examiner-Henry C. Sutherland [72] Inventor. Jack N. Schmitt, Birmingham, Mich. Anamey cunen, Settle, Sloman & Cantor [73] Assignee: Truswal Systems, Inc., Troy, Mich.

57 ABSTRACT [22] Filed: Nov. 18, 1970 1 A truss-type floor joist formed of vertically aligned parallel [2n Appl' 90,579 chords connected together between their ends by alternating diagonal web members and at their ends by a pair of vertical 521 0.5. CI. ..52/693, 52/642, 52/730 end members arranged in face-04m 60mm with 511 Int. Cl ..E04c 3/12 chmds, web members and end members 2x4 58 Field of Search ..52/639 642 690 693 696 StripS arranged with their edges Each 5 chord has an inner liner member in the form of a 2X4 wood strip member arranged in face-to-face contact therewith and extending from each end of the chord to a point just past its [56] References Cited first, adjacent set of diagonal web members. Each of the joints UNITED STATES PATENTS formed by abutting web members and end members with the chords are overlapped on both vertical faces with metal con- 2,385,l42 9/1945 Lank ..52/639 nector plates having struckout teeth embedded in the respec 2,886,857 5/1959 Brosenius .....52/639 fi overlapped wood membem 3,170,198 2/1965 Snider ..52/642 3,53 1,904 10/1970 Sanford ..52/642 2 Claims, 4 Drawing Figures S a f 1 a 4 /3 /4a a Patented March 28, 1972 FIG. I

mvemoa JACK N. SCHMITT ATTORNEYS FLOOR JOIST BACKGROUND OF INVENTION 1 Floor joists used to support the floor in a small building, and similarly used to support flat roof sections, have been typically made of large wood beams, such as 4X8 and 2X6 in cross section, or alternatively, out of metal I-beams. Suitable lumber for this purpose is relatively expensive and difficult to obtain and process. Likewise, metal I-beams are also relatively expensive and difficult to handle and assemble into the building construction.

Thus, the invention herein relates to floor joists formed in a truss-like shape out of conventional, readily available and inexpensive 2 4 wood strips which joists may then be used in small building construction such as in dwelling houses, for floor joists as well as ceiling joists where appropriate.

SUMMARY OF INVENTION The invention herein contemplates forming floor joists in a truss-like configuration out of long, parallel chords made of conventional 2X4 lumber with the chords interconnected by alternating diagonally arranged 2X4 web members and vertically arranged end members with all joints connected together by means of conventional flat, sheet metal connector plates which include integral struck-out teeth for embedding into the wood. Such type connector plates are illustrated for example in the patent to Broder, US. Pat. No. 3,242,788 granted Mar. 29, 1966.

More specifically, the invention herein contemplates forming the opposite ends of the chords in double thickness by means of inner, short length 2X4 liners arranged in face-toface contact with the opposite inner surfaces of the chords, and also forming the vertical end supports in double thickness 2X4 members and doubling the thickness of one of the two diagonal web members, whichever is the first tension loaded member, which are arranged between the doubled end portions of the chords. The 2X4s on all the members are arranged horizontally, that is, their thin or narrow edges are in the vertical plane and their wide edges are in the horizontal plane. Further, the doubled thickness members, being unconnected to each other except along the vertical plane by means of the vertical arranged connector plates, have some limited movement relative to each other to absorb stresses and strains and to avoid any tendency to crack or split lengthwise, thus forming a joist which may be of considerable length, yet of a high degree of stiffness and strength with minimal tendency to crack under varying loads.

Hence, an essential object of this invention is to form a truss-type joist of considerable strength and rigidity yet of low cost using readily available and low cost 2X4 lumber.

Other objects and advantages of this invention will become apparent upon reading the following description, of which the attached drawings form a part.

DESCRIPTION OF DRAWINGS FIG. 1 is an elevational view of one end of the joist. FIG. 2 is an enlarged, perspective view of the opposite end of the joist, and

FIG. 3 is an enlarged, fragmentary view of a section taken in the direction of arrows 33 of FIG. 2.

FIG. 4 is an elevational view of the end portion of a modified joist.

DETAILED DESCRIPTION FIG. 1 illustrates a floor joist which is of considerable length relative to its height. For example, typical sizes would run approximately 24 feet long by 16 inches high or 28 feet long by 20 inches high or 32 feet long by 24 inches high. Obviously, the length may be varied considerably whereas the height is relatively low compared to the length and varies only slightly despite increases of length.

The joist is formed of an upper chord l l, a lower chord 12, with the chords interconnected by sets of alternating diagonally arranged web members 13 and 14 and by opposite end vertical end members 15.

As illustrated in FIGS. 1 and 2, the upper chord 11 is formed of anouter, long 2X4 wood strip 17 having an inner, short 2X4 wood strip 18 arranged in face-to-face contact at its opposite ends. Likewise, the lower chord 12 is formed of a long 2X4, outer wood strip 19 having its opposite inner ends lined with a short 2X4 wood strip liner 20.

Each of the vertical end members 15 are formed of a pair of 2X4 wood strips 21, arranged face-to-face. Also, the diagonal web member 14a which is second from each of the opposite ends, and which is normally under tension, is formed of a pair of 2X4 wood strips 22 and 22a arranged face-to-face. In the event the joist is to be so loaded that the first web members 13a (the ones nearest to the joist ends) are to be in tension, then that first web member is formed of a pair of 2X4 wood strips, instead of the second web members 14a.

As is illustrated in FIG. 2, all of the 2X4s are arranged on their sides, that is, with their broad or wide faces in the horizontal plane and their narrow edges in the vertical plane.

The reference herein to 2X4 wood strips refers to conventional lumber, commonly called 2X4 meaning 2 inches by 4 inches in cross section, but actually of a slightly smaller size when the lumber is dressed. The size of the wood strips is not critical and may be varied somewhat but the size herein referred to indicates the use of the conventionally available inexpensive wood strips as contrasted with the previously used large size wood beams which are relatively expensive, tend to crack and are not readily available.

The opposite ends of the web members abut the interior surfaces of the chords as does the opposite ends of the end members 15 to form joints which are connected by means of conventional, fiat sheet metal connector plates of the type illustrated, for example, in the above-mentioned Broder US. Pat. No. 3,242,788-of March 29, 1966. These plates consist of flat sheet metal having struck-out teeth of suitable configuration for embedding into the wood.

FIG. 3 illustrates a corner joint wherein the plates 25, arranged on each vertical face of the joint have their teeth 26 embedded into the chord strips 17 and 18 and into the vertical end members 21. The plates are typically secured into position by first arranging all the wood parts in their proper relationship, then placing the plates above and below the joints and squeezing them into the wood by meansof a suitable press.

The size of the plates may vary, depending upon the size of the joints and thus, large plates 24 may be used on most of the joints with smaller plates 25 at the joints of less area.

As described above, the double thickness portions of the chords, web member 14a and end members 15 are so formed that the two strips making up the double thickness are relatively movable to the extent that they are not fastened face-toface but are fastened together only on their vertical edges by means of the plates with the embedded teeth so that there is some degree of relative movement or relative buckling permitted between the double thickness members which functions to better absorb stresses and to yield thereunder and to avoid cracking or splitting which frequently occurs in heavier, prior types of wood beams. Thus, the double thickness members are for all practical purposes not secured together except at their ends and then only along their side or vertical edge faces so as to permit this relative movement or buckling.

However, for some constructions, it is desirable to anchor the double thickness portions of the chord further for suitable strength requirements. Thus, FIG. 4 illustrates a modification wherein the upper chord is provided with an additional connector plate 28 at the free end of its inner or liner wood strip 18 and the lower chord is provided with a similar connector plate 29 midway between its ends. The inner and outer members of each chord are still free to move slightly relative to each other particularly since they are secured together only along their vertical faces by the embedded connector plate teeth.

vention, I now claim:

1. A floor joist comprising:

a pair of long, vertically spaced apart, parallel chords, each formed of a long outer 2X4 wood strip and a pair of short inner 2X4 strips extending from the outer ends from the long outer wood strip a short distance towards the center thereof, the inner strips being in loose face-toface contact with the respective outer strips to form double thickness short end portions on each chord, and with the 2 4 strips all laid on their sides so that their opposite narrow edges are vertical and coplanar;

a vertical end member spanning the space between and endwise abutting the inner chord strips at each opposite end thereof; each end member being formed of a pair of 2X4 wood strips arranged loosely together face-to-face with their narrow edges in the same planes as the corresponding chord strip narrow edges;

sets of alternating diagonally arranged web members extending along the length of the chord, with each web member diagonally spanning the space between the chords and endwise abutting the opposed inner surfaces of the chords, and with each formed of a 2X4 wood strip having its opposite narrow edges coplanar with the chord strip narrow edges;

a vertically arranged, flat sheet metal connector plate overlapping each of the vertical faces of each joint formed between the web members and the chord and the end members and the chord and secured to same by integral struck-out teeth embedded therein for securing the members and chord together;

with the plates overlapping the end member joints also overlapping and securing the outer and inner chord strips together and the plates overlapping the first set of web members closest to the end members also overlapping and securing the outer and inner chord strips together;

and the inner chord strips terminating only a short distance from said first set of web members;

the pairs of strips forming the double thickness chord end portions and the end members having their contacting faces free of securement to each other and being slightly relatively movable for absorbing stresses and avoiding longitudinal splitting.

2. A floor joist as defined in claim 1 and wherein the first tension loaded web member from each opposite end of the joist, that is, one of the two of the nearest set of web members to each opposite end which is to be loaded in tension, is formed of double thickness 2X4 wood strips, with the remaining web members being of single wood strips.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US2385142 *Dec 14, 1943Sep 18, 1945Timber Engineering CoTimber truss and the like
US2886857 *Dec 14, 1953May 19, 1959Hyresgaesternas Sparkasse OchWooden beam constructions
US3170198 *Jun 22, 1960Feb 23, 1965Snider Eliot IWooden i-beam
US3531904 *Jun 17, 1968Oct 6, 1970Sanford Arthur CReinforced construction for wood stress members
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3867803 *Sep 27, 1973Feb 25, 1975Richardson Lumber CompanyFlat joist truss with rounded load-transfer surfaces
US3961455 *Oct 21, 1974Jun 8, 1976Peters Dierk DTruss support connector
US4160350 *Jul 3, 1978Jul 10, 1979Craib Rupert GFloor joist plate
US4207719 *Apr 3, 1978Jun 17, 1980James KnowlesComposite construction beam
US4228631 *Sep 12, 1978Oct 21, 1980Geffe Bruce THollow rectangular joist
US4457118 *Aug 14, 1981Jul 3, 1984Bowen Alfred JIntegral foundation and floor frame system and method of building construction
US4641480 *Jun 3, 1985Feb 10, 1987Inter-Lock Steel Company, Inc.Combination connector plate and tail truss
US4659604 *Feb 20, 1986Apr 21, 1987Boise Cascade CorporationBonding metal and wood with epoxy or isocyanate type adhesives
US4891927 *Nov 23, 1988Jan 9, 1990Metsaliiton Teollisuus OyJoint for connecting wooden beams to each other, and the use of the joint in roof truss structures
US5560177 *Mar 4, 1996Oct 1, 1996Brightwell; Lionel L.Trimmable open web joist
US5592800 *Jan 20, 1995Jan 14, 1997Truswal Systems CorporationAdapted for load bearing
US5761872 *Aug 19, 1997Jun 9, 1998Sanford; Emmett BarryVariable length truss and method for producing the same
US5867963 *Sep 23, 1997Feb 9, 1999Truswal Systems CorporationTrimmable truss apparatus
US6139667 *Aug 21, 1997Oct 31, 2000Sanford; Emmett BarryVariable length truss and method for producing the same
US6256958Mar 22, 1999Jul 10, 2001Perf-X-Dek, L.L.C.Floor joist system
US6568134 *Jul 20, 2001May 27, 2003Thomas E. KerneyComponentized, three dimensional, self-aligning, self-engineering building system for homes, and modeling blocks therefor
US6651306Jun 16, 2000Nov 25, 2003Mitek Holdings, Inc.Apparatus and method for fabricating flat trusses
US7093628Oct 5, 2001Aug 22, 2006Mitek Holdings, Inc.Method of and apparatus for forming timbers with rounded ends
US7409804Dec 9, 2004Aug 12, 2008Nucon Steel CorporationRoof truss
US7509781Apr 17, 2001Mar 31, 2009Romaro 2000 LimiteeStructural wooden joist
US7513085Oct 24, 2003Apr 7, 2009Nucon Steel CorporationMetal truss
US7735294Aug 12, 2008Jun 15, 2010Nucon Steel CorporationRoof truss
US8006461Aug 12, 2008Aug 30, 2011Nucon Steel CorporationRoof truss
US8122676 *Apr 16, 2009Feb 28, 2012Solive Ajouree 2000 Inc.Top-chord bearing wooden joist
US20120076977 *Sep 27, 2010Mar 29, 2012Weyerhaeuser Nr CompanyReinforced wood product and reinforcement component
US20120324827 *Jun 23, 2012Dec 27, 2012James ForeroBracing system for reinforcing beams
CN101949212A *Sep 29, 2010Jan 19, 2011中冶建筑研究总院有限公司;中国京冶工程技术有限公司Slabform detachable support system and construction method thereof
CN101949212BSep 29, 2010Apr 25, 2012中冶建筑研究总院有限公司楼板可拆模板支撑系统及其施工方法
Classifications
U.S. Classification52/693, 52/642
International ClassificationE04C3/12, E04C3/16
Cooperative ClassificationE04C3/16
European ClassificationE04C3/16
Legal Events
DateCodeEventDescription
May 9, 1988ASAssignment
Owner name: HOUSEHOLD COMMERCIAL FINANCIAL SERVICES, INC., 270
Free format text: SECURITY INTEREST;ASSIGNOR:TRUSWAL SYSTEMS CORPORATION, (A DE. CORP.);REEL/FRAME:004889/0168
Effective date: 19880217
Owner name: HOUSEHOLD COMMERCIAL FINANCIAL SERVICES, INC., ILL
Apr 18, 1988AS02Assignment of assignor's interest
Owner name: ITW TRUSWAL CORPORATION, 8925 STERLING STREET, IRV
Effective date: 19880217
Owner name: TRUSWAL SYSTEMS CORPORATION
Apr 18, 1988ASAssignment
Owner name: ITW TRUSWAL CORPORATION, 8925 STERLING STREET, IRV
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:TRUSWAL SYSTEMS CORPORATION;REEL/FRAME:004860/0503
Owner name: TRUSWAL SYSTEMS CORPORATION, 8925 STERLING STREET,
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:ITW TRUSWAL CORPORATION;REEL/FRAME:004860/0507
Effective date: 19880217
Owner name: ITW TRUSWAL CORPORATION, A CORP. OF DE, TEXAS
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:TRUSWAL SYSTEMS CORPORATION;REEL/FRAME:004860/0503
Owner name: TRUSWAL SYSTEMS CORPORATION, A CORP. OF DE, TEXAS
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:ITW TRUSWAL CORPORATION;REEL/FRAME:004860/0507
Jan 12, 1988AS06Security interest
Owner name: HOUSEHOLD COMMERCIAL FINANCIAL SERVICES, INC., 270
Owner name: TRUSWAL SYSTEMS CORPORATION :
Jan 12, 1988ASAssignment
Owner name: HOUSEHOLD COMMERCIAL FINANCIAL SERVICES, INC., 270
Free format text: SECURITY INTEREST;ASSIGNOR:TRUSWAL SYSTEMS CORPORATION;REEL/FRAME:004876/0492