US2327655A - Heel connection - Google Patents

Description

Aug. 24, l943- c. MAclN'rosH 2,327,655

HEEL CONNECTION Filed Jan. 19, 1942 I I', l /H Y fai;

Patented Aug. 2.4, v41.943

UNITED STATES yrar par orgies aamssv y HEEL C()NJ.\IEC'1I0I1Ty Charles'Mackintcsh, Los Angeles, Calif;

Application January 19, 1942, Serial- No. 427,382' A (Cl. :w8- 23) 13A Claims.

This invention relates totruss constructions, for example, such as are used inv supporting roofs of building structures of various kinds, and has for its ,general` objectthe provisionv of a novel and improved. heel connection at .the junctions of the'upper and lower chordsatthe ends of the truss. The means very ccmmonlylemployed' iny effecting this connection involves the provision of a relatively broad generally U-shape'd: fstrap or shoe which'. embracesthe ends. of. the members of the lower chordto-which it is secured byl means of a double row of bolts, andthe bight of? which provides a socket' or stirrup within which. the end of the upper chordiisv received and against' which it abuts. One seriousdisadvantageof such4 constructions, especially when u'ns'easonedV orincompletely seasoned lumber isused, lies in the tendency of the members of either the upper or lower chords, or both of themtolsplit either. along. thelines of Vthe bolt holes or between.v them. Thisis due to theY subsequentshrinkage ofi the wooden chord. members after being rigidly secured. at spaced 'xedpoints tothe metal shoe.

In its preferred embodiment, the inventionfcontemplates the provision; of aheel connection for a` trussJ of the general class described. in which the upper andi lower. chord ends are secured. together tocomplete the unitary truss frame, by

` means oftwo or morespaced. strapsoif` generally U-shaped con'guration'.' Each of thestraps is preferably secured' to the members of the lower chordby means ofy bolts' which 'pass through the chord: members andfbothof the'paralle'l arms of the straps; The'spaoing between corresponding arms of adjacent; straps. should, of course, be greater than the, maximum expected shrinkage ofr the woodenmembersof the lower chord. The bight's of the straps encloselthe endf of the upper `chord andy provide a plurality of stirrups for taking the endwise pressure of'. the upper chord elements. 'Preferably a thrustlplate or block is in- Vsertedwithi'n the bights o'thex straps to provide a. more solid and unitaryI surfacexfor the upper chord. i f

In a modified. form ofthe` invention, the straps enclose the lend portion of the upperA chord. only and thedivided ends. of the lower chord; extend areasvvlfiich` are secured. to the individualnarrow straps. i

Provision is also made for tying; in the truss heel connection with the post or column upon which it is supported and also with the. plates which extendV between thev posts-at rightfangles to the truss, and which, together with'the posts and sills, define the bays of the side walls-cf the building. These baysniayfbe cross braced by means of diagonal tie rods or the like, provision being made in the novel heel connections for anchoring the upper-ends-of such rods.

Other objects and features ofI novelty will be apparent from the followingA specification when read'in connection with thel accompanyingdrawing in which one embodiment of the invention is I illustrated by way of example.

alongside of. the end1of the.uppe'r chord in overlapping. relationship. The bolts4 securingl the chordsand thevstraps together pass all theway through the overlapping. portions of the`three members. I If desired, the endszofthe lower. chord members may be kerfedonslottedf so/ that slight relative `movementy mayv takeI place between'Y the In the drawing:

Figure l is a fragmentaryview infront elevation of one-end portionof a trussembodying the principles ofv the invention, one Aof 'the `plates which connectysuccessive trusses and columns being shown in cross section;

Figure 21isa horizontalsectionallview taken substantially on line 2-2 of Figure 1; V

Figure 3fis a viewin end elevation` ,oft-he' heel connection. of the truss and showingother connecting yelements for the posts or. columns;

, Figure 4 Vis a fragmentaryperspective` view of the heel connection,` the ro'of' platesbeing omitted for the sake of clarity oi illustration;-

Figure 5 isa view similar to Figure l,.but showing a prior art construction andthe results of employing such a heelconn'ection with unseasoned lumber; Y u

Figure 6 is afragmentary view in side elevation in a. modiedform-of truss heel; and

Figure 7 is a View in horizontal section taken on line 'lyof Figure 6.

The novell truss connection illustrated and described in the present specificationissho'wn as `heel connection may be embodied inltruss assem- -bliesoii any typeandadaptation. l

In the exemplaryembodim'ent illustrated-each extent of the chords. member I3 of the upper chord is indicated at IS,

truss comprises an upper chord element IB and a lower chord element I2, each of which is composed of one .or more spaced timbers, the members comprising the upper chord i and indicated at I3 and I4 and those forming the lower chord I2 at I5 and l5. Of course, as in the usual case, the upper and lower chords are braced throughout their length by means of vertical or diagonal struts or webs, the ends of which may conveniently be received and secured between the upper chord timbers I3 and I4 and the lower chord members I5 and I6. Obviously, the members I3 and I4, and I5 and I6 are not continuous, but comprise a series of timbers spliced together at their abutting ends at intervals throughout the For example, a splice inthe the ends of the timbers I9 and 20 forming the member I3, abutting at ,the joint and being secured together bymeans of the block 22 which overlaps the ends of thetimbers I9 and 2t and is secured to them by means of the bolts 23.Y The splices between the timbers of the upper chord elements I3 and I4 are staggered, the end timber of the element I4 being indicated at.

The heel connection between the upper chord I and the lower chord I2 is effected by the ccmposite'shoe shownV to the best advantage inFigure 4 of the drawing.l The shoe 'comprises essentially the two vertically spaced `Ushaped straps 21 and 28, the bights 30 of these straps passing around the end of the upper chord I@ and the arms 3I and 32 of the Vrespective straps extending alongside of the end of the chord I0 and also extending along both sides of theend portion of the lower chord I2, which terminates at the diagonal line 33 in close proximity to the end of the upper chord Ill.

In the simplest-l form of the construction, the

spaced members I3 and I4 of the upper chord' and members I and I5 of the-lower chord are merely received between the arms 3| and 32 of the straps 21 and 28v and the Vrespective timbers bolted tov the straps, but-in order to provide a more firmly bracedy construction, blocks 35 and 36-may be respectively interposedV between the upper chord elements I3 and I4 and the lower chord elements TI5 and IB at the extreme ends to hold the elements apart and make a snugger and moreV rigid clamped connection at the shoe.

The bolts 31 pass through the parallel arms 3I and 32 of the straps 21 and 28, through the members I5 and I 6 of the lower chord, and through the insert block 35. Two vertically aligned bolts 38 and a bolt 39 are shown extendingthrough the arms of the straps, the elements I3 'and I4 .of the upper chord, and the insertblock 35. These latter bolts are optional but may be employed to further rigidify the heel connection. The extreme end of the upper chord I0 is `beveledY off horizontally toprovide a rm seat upon the upper end of the column or post 45|.V This seat may be through direct Contact of the chord with the `top ofthe post, or a bearing plate of any conventional type may be interposed between the memf bers. Since the lower chord I2 is a tension elementand is sufcientlyconnected or ,tied into'the trusses structure by means of the bolts 31 and the straps 21 and 2B, this chord needs no Afurther connection with the supporting structure.

In'orderf to provide a more rigid unitary seat for the' end ofthe upper; chord Ill within the bights 30 of thestraps 2.1 andiZB, a thrust plate 42 is provided, this plate being of a vertical extent exceeding the combined height ofthe two embraces the ends of the lower chord I2. rowsof bolts 31 and 38 lare employed for an` -weakness in the truss.V

tures together.

straps and being provided preferably with round- I ed or beveled corners as at 43 in order to conform to the bights 33 of the stra s. forcing or thrust plate 42 may be tack-welded as at 45 and 4S to the respective straps 21 and 28 in order to maintain the relative positions of these elements.

In Figure 5 of the drawing, a heel connection is shown which typifles prior art construction in which the upper chord I0' and the lower chord I2 are joined by means of the broad U-shaped shoe 21', the bight 3G of which surrounds the end of the upper chord IG which rests upon the post 49' and the arms or side Webs 3l' of the shoe Two chorin'gthe lower chord I2 to the heel connec tion.V In periods -of great demand for lumber,

as in war times or during buiding booms, it is dicult to obtain thoroughly cured and dried lumber for use inbuildin'g construct-ionsof this type, practically all of the supply being used asrapidly as it is cut. In such a case the unseasoned Y or only partly seasoned lumber is liable to great shrinkage after erection of the buildingand in a `great percentage .of theV heel connectionsv con-r structed in accordance with the prior art example shown, the lower chords have split atV any one of vthree places in' the vicinity of the' shoe, either .along the liney of the lower rowof bolts 33-as shown at'I Ile-along the line of theupper row of boltsS'I, or at some point between these lines of bolt connections. `Such .failures are exv tremely Vcommon and one of the objectives of the present vinvention isl to yeliminate this source'of It will be readily seen that in the use of the composite shoe afforded by the present invention, the lower. chord members may shrink` to` theirfullest extent without causing a splitiatthe heel connection because of the ilexibility' of the compound shoe, the straps 21 and 28 being-free to move with relation to each other in response to any vshrinkage in the timbers.

In pursuing the further object of theinvention,

. provision is madefor extending the heel connectionto provide.: guides andsupports for the plates which t'ieithe successive trussand column struc- 'Anglebrackets 50 are disposed upon eitherside of the post 40 'adjacent the extreme upper end thereof. are bolted to the post bymeans' of the bolts 5I which may be either screw bolts employed individually for the respective angle `bracketslor may be elongated and extended right through the post 40 and the .flangesof the brackets of both sides thereof. The ends ofthe plates rest upon and are secured to the 'horizontal flanges of the angle brackets 53. as "clearly shown in Figure 3 of the drawing; 'I'he ends ofthe plates abutthe i weld or tack weld shown at 63'.

shoe 21, 28 andare secured thereto in proper scribed in relation to the connectionbetw'een the shoe andthe upper chord. Bolt 62 servesto con'- nect the bracket with the vpost A40:' andthe bracket 60 may be. furtherconnected with the horizontal bracket 50 as by means ofthe spot Bolts sse'rve'to connect the bracket 6,3 with the plate 55. InV the The reineY These angle brackets lowermost portion'oftl'e angle bracket 6,0 andlin alignment with the, openings provided-with the boltsi, 'an openingy (il: affords meansfor. securing thevdia'gonal tie rodsiito the heelfconnection. These tie rods providef crossbraoing. for i the bays` of the sidewalls offthe building and the lower` ends thereof may be secured -tof the lower portionsof tbe next adjacent columns 40 or to theV sills of the.buildingnstructure inthe Vicinity of such columns, as well known: in the art. l l

In the modiiication illustrated in Figuresl and '7 of theV drawing, a portion-of the upper chord isindicatedA at' lll' and the endoflth'e lower chord atl IIZ. `fheendiof the upper chord is embraced by.v spaced U-shaped strap members Irland" |28 each provided with parallel. arms |31: and |32. A plate I isiinserted in the big'ht of the straps totake thethrust of the chord. The lower chord H2' comprises two members H5 and. l'which vextend. alongside" ofV theA end' of the upper `chord Vand t closely against the outersides-of' the arms of` the straps. vA row of'transverse-bolts |31 pass through the arms itl of the straps: and also through the enclosedend' offthe upper chord and v `the upper portions of the members/I |5land iii;

ofthe lower'chord.' A similar row ofboltsl |31' pass through the arms |32' of the lower strap 28 and theV lower portion of! the chord members lliland M6.. VCertain of these latter bolts also passithrough enclosed: portions of the end of the upper chord. l'

Optionally, the members H5 and H6 of the `lower chordrmay be-kerfed als at 150s() as to in,-

hibit the splittingofthe ohordf elements due to contraction of the wood. These kerfsare preferably made by drilling an` opening through the cliordimembers as at |5I. and then sawing a slit longitudinally from the end' ofJ the members to meet the drilled opening. If desired, it' is-Within the purview of this invention to kerf the endsof the members ls'` and Iii of thel lower chord vI2 in thel embodiments previously described." v

"'B'y `means of the` structures just described, there is provided a convenient and! useful building connection which lgreatly facilitates the erection of wooden buildingsof various types and definitely obviates serious deiiciencies in prior constructions. It is understood that various changes or alterations can be made in the em-v bodiment illustrated and described herein Without departing from the scope 0f the invention as defined in the following claims.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent is:

1. A truss construction comprising in combination, an upper chord, a lower chord, and a connection between said chords at the adjoining ends thereof, said connection comprising a plurality of vertically spaced U-shaped straps, each of said straps embracing the end of at least one of said chords and separately secured to said chords by fastening means disposed in a single substantially straight line and means connecting said portions of the straps together to form a unitary connection element which will permit some independent movement of said straps to accommodate any possible changes in the vertical transverse dimensions of the members of the truss.

2. A truss construction comprising in combination, an upper chord, a lowerchord, and a` connection between said chords at the adjoining ends thereof, said connection comprising a -plurality of Ua-shaped. metal straps. embracing. the end'iof"4 atleastlone ofsaid chords, well distributed'l across the'height :of the lower chord and spacedapart by at least the distance equal to the-maximum shrinkage at such'spaces of the woo'dl ofwhicl-il the lowerV chordis composed, each 'ofi said strapsY beingsecured to .the lower chord by fastening means. disposed 'in a single substanvtially-/straight.line substantially parallel with the ydirectionfof longitudinali extent `of said lower 3. truss "construction comprising in` combinatiomian.rupper.-.chord, a` lowerchord,` and a connection between said. chords at the adjoining ends thereof;4 said connection'` comprising a pluralityof U.shaped"straps, thearms of said straps being disposediparallel witl'rsaidl chord ends and 'eacli` secured thereto by fastening means disposed ina'singlesubstantially straight line, one "of: saidlchords beingv kerfed along a line between :the straps. i l f 4. A truss construction `nation, an upper chord, a lower chord comprising. two substantially `horizontal parallel membersspa'cedapart and extendingV along both sides of the endfoff the upperchord, and a connection between said. chords comprising a plurality oi vertically spacedfULshaped straps embracing the end of the upper chord. and having their arms disposed:betweenfsaidupper chord and the menu bers of the lower! chord, `saidfstraps being spaced apart to accommodate any change in the vertical= transverseV dimensionsdof. the .lower chord, and fastening meanspassing througheach of said far-msi and both chords and disposed in a single substantiallyY straight line;

5'. A truss construction for supporting roofs of buildings or the 'like comprising,` in combination, an upper chord, the ends of which are adapted to rest upon a. supporting structure, a lower chord providing ya tension element or the truss and: suitably connected with said upper chord at intermediate points, theends ofsaid upper chord -overlappingfthe corresponding" ends of the lower chorclzin` al longitudinal direction, a heel conn-ectiony for` each? of the .adjoining ends of the two chords'wl'iich comprises a` plurality of relatively narrow U-shaped straps, the respective arms of which extend along opposite sides of the lower chord in parallel spaced relation to each other, each pair of arms being secured to said lower chord along a single Ystraight line, the bights of said straps embracing the end of said upper chord to take the thrust thereof and means connecting said straps together adjacent'their bights not only to provide a unitary connection member but to permit some independent relative movement of said straps to accommodate any change in the vertical transverse dimensions of members of the truss.

6. For use in providing connections between one end of a roof truss of a building and the adjacent columns and plates, a unitary assembly comprising a plurality of parallel spaced apart U-shaped straps, the arms of which are adapted to embrace an end of said truss, a thrust plate received within the bights of said straps for directly receiving the thrust of the truss, means securing saidv thrust plate to said straps, an angle bracket on each side of the assembly connecting the arms of said straps adjacentY the bights thereof and having a flange adapted to abut and be secured to the adjacent plate.

7. For use in providing connections between one end of a roof truss of a building and the comprising in combiadjacent columns'and plates,.a unitary assembly comprising a-pluralityof parallel spaced apart U-shaped straps, the arms of which are adapted to embrace an 'end 'of said truss; a thrust plate received within the bights of said straps for directly receiving the thrust of the truss, said thrust plate being tack welded to said straps, an angle bracket on each side ofthe assembly connecting the arms of said straps adjacent the bights thereof and having a flange adapted to abut and be secured to the adjacent plate, anotherkangle bracket secured to the lower end of each of said rst named brackets, adaptedto underlie the adjacent plate, and having flanges adapted to be secured to the plate and the column.

8. A truss construction comprising, in combination, an upper chord,va lowerchord, and a connection between said chords in the adjoining ends thereof, said connection comprising an end abutment member and a plurality of vertically spaced, relatively narrow straps rigid with and extending from said member along each side of said chord ends, fastening means securing said straps to at least one of said chords, said straps being spaced apart to accommodate the maximum expected change in the vertical transverse dimensions of the' chord to which it is secured.

9. A truss construction comprising, in combination, an upper chord, a lower chord, and a connection between said chords in the adjoining ends thereof, said connection comprising an end abutment plate and a plurality of vertically spacedstraps secured to and extending from said plate along each side of said chord ends, and fastening means securing said straps to atleast one of said chords, said straps being spaced apart to accommodate the maximum expected change in the Vertical transverse dimensions of the chord to which'it is secured.

10. A truss construction comprisingA in combination, an upper chord, a lower chord, and a connection between said chords at the adjoining ends thereof, said connection comprising a unitary member of generally U-shaped configuration embracing the end of at leastrone of said chords, said member comprising a transverse base element adapted to abut saidchord end,

vand a plurality `of 'metal straps Asecured to said base element Vand extending along each side of the chord ends, said straps being Well distributed across the height ofthe lower chord and spaced Vapart by at least the distance equalto the maximum shrinkage at suchl spaces of the Wood of which the lower chord is composed, each of said straps being secured to the lower chord by fastening means disposed in a singlesubstan-` tially straight line substantially parallel with the direction of longitudinal extent of said lower chord.` f "L 11. A trussconstruction comprising, in combi'- nation,` anupper chord, a lower chord, anda connection between said chords at the .adjoining ends thereof, said connection comprising a unitary member ofgenerally U-shaped configura.- tion,V said member comprising a transverse 'base element adapted to abut said chord end and a plurality of metal straps secured to said base element, said straps being disposed parallel with said chord ends and each secured thereto by fastening means disposedin a single substantially straight line, one of said chords being kerfed along a line between the straps.

12. As an article of vmanufacture for use in providing connections between the upper land lower chords of a roof truss or the like, a unitary substantially U-shaped member adapted to embrace thel ends of a truss, said memberrcomprising a substantially rectangular base plate and a plurality of parallel spaced arms extending from each of a pair of opposite side edges of the plate and perpendicularto the plane of the'plate, the spacing between said arms on the same side of the member` being equal to any expected shrinkage of a wooden structural member .Y to which the arms may be secured, said arms being of strap metal of some slight flexibility toaccommodate relative movement ldue to such shrinkage. i

13. The truss construction as set forth in claim 5 in which the strap connecting means comprises a unitary thrust plate received within the bights of all of said straps and bearing against the end surface of the upper chord. V

CHARLES MACKrN'rosH.

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