US2815831A

US2815831A - Column and rafter assembly for rigid frame buildings

Info

Publication number: US2815831A
Application number: US558084A
Authority: US
Inventors: Roger A Hield; Carmen L Ramirez
Original assignee: Butler Manufacturing Co
Current assignee: Butler Manufacturing Co
Priority date: 1956-01-09
Filing date: 1956-01-09
Publication date: 1957-12-10
Anticipated expiration: 1974-12-10

Description

Dec. W, W57 R. A. HBELD ETAL COLUMN AND RAFTER vSSEIIVIBLX'FOR RIGID FRAME BUILDINGS Filed Jan. 9, 1956 3- Sheets-Shea?I l Dec. 10, 1957 R. A. HIELD ET A1. 2,815,831

COLUMN AND RAFTER ASSEMBLY-FOR RIGID FRAME BUILDINGS Filed Jan. 9, 1956 t i5 Sheets-Sheefl 2 Eby- 4' 1N V EN TORS.

BY f 14 TTOKNEK Dm., W, 1957iy R A" HIELD ET AL wam COLUMN AND RAFTER ASSEMBLY FOR RIGID FRAME BUILDINGS Filed Jan. 9, 1956 .'5 Sheets-ShagC 5 J'L. MHUWIHU' 4 Amam United States Patent Q CLUMN AND RAFTER ASSEMBLY FOR RIGID FRAME BUILDINGS Roger A. Hieid, Kansas City, Kans., and Carmen L.

Ramirez, Kansas City, Mo., assignors to Butler Manufacturing Company, Kansas City, Mo., a corporation of Missouri Application January 9, 1956, Serial No. 55%,084

9 Claims. (Cl. 189-1) Rigid frame structures A rigid frame building is `one which is structurally stable by virtue of the rigidity of its joints, as differentiated from a trussed structure which is stable because of the triangular arrangement of its members. The invention is applicable to one story gable bents of rigid frame construction covering large open areas wherein a raftered roof structure is built integrally with wall columns.

Rigid frame structures of such described type are now quite common and in many building applications have replaced the ordinary roof truss and column structures of past times. The various frame members of a rigid frame structure are generally referred to as the column, the rafter and the knee. The knee is that area or joint at the eave which connects the column and rafter members together'. The knees ties the structure together and makes it a unit to carry all loads whether ythey be vertical loads on the roof or lateral loads on the Vertical projection of the building.

Rigid frames are somewhat similar to arches in their action. They are similar to arches in that they produce a lateral thrust at their bases. In gable type frames this thrust is not very great and can usually be carried by the ordinary type of floor and footing construction. The rigid frames can be made fixed or free (hinged) at their column base. A hinged column base keeps foundation costs at a minimum and is therefore preferable. Rigid frame structures belong to a general class of structures called continuous structures. This term applied because the structural action and stress travel are continuous throughout the structure, there being no joints in a structural sense. Because of this, the entire structure must be stress analyzed as an integral unit and cannot be con'- sidered as an assembly of separate members.

Rigid frame types of buildings are essentially merely an enclosing shell around the necessary functions of the building and the structure itself uses up little of the enclosed building Volume. Such a construction contributes to economy and the usable interior dimensions always govern the outside dimensions of the building. A rigid frame building requires a height from two to ve `feet less (depending upon span) than that required by a comparable truss and column construction. The structural frame of buildings of this type when erected and placed present a Very rigid type of construction even before the enclosing walls are in place. The structure is very Ipleasing to the eye in that it is clean and clear cut. The

2,3 l 5,83 l Patented Dec. l0, l 957 absence of the usual maze of steel members found in a truss type construction is notable.

Rigid frame buildings are designed for live 'and wind loads plus dead load. Dead load is the weight of the building itself. Live load can be any load that can be applied to the building but is usually thought of as snow load and is considered as acting vertically over the horizontal projection of the roof. Wind load is 1also a live load but is considered separately because the wind load is considered to act horizontally on the Vertical projection of the building. Wind tunnel tests show that the wind load on buildings will vary for each different size and shape and that the wind load will act as a pressure on the Windward side and as a vacuum on the leeward side of the building.

The principal stresses of a rigid frame are due to bending. The shears and thrusts are of little consequences except that the direct compression in the columns and roof beams is usually an appreciable stress. The knee is the strongest section of the frame. This condition is required by vertical load consideration, but at the same time gives the frame a very great lateral strength. Since the knee is always the section requiring the greatest strength it has greater depth than any other point in the frame. The structural performance of the knee section is rather complex in that there is a sudden change in the direction of stress in traveling around the sharp corner between the column and the rafter. members. However, the design of the knee has been well established on a rational basis by a` considerable number of tests, some of them relatively large size members. These tests indicate a nonlinear stress distribution around the corner with a neutral axis of moments displaced toward the inside corner of the knee.

Rigid frame structural members In rigid frame buildings of conventional construction, the main frame members are generally L-sh-aped column and rafter members the L-shaped members being used `in opposed pairs which are joined at the ridge of the roof. In such L-shaped members, the web is preferably widest at the junction between the column and the rafter `since this is the point at which the load and stresses are greatest. The column tapers downwardly from this point and the rafter likewise tapers toward the ridge, all in accordance with good engineering design.

A few manufacturers of Prefabricated buildings make the entire L-shaped member (one column and its attached rafter) as a single integral unit. However, this presents a tremendous storage problem at the factory, not to menj tion the problem of shipping such units to the site Where the building is to be erected. Accordingly, it is amore common practice to make this member in two parts which are assembled at the job site. In such a conventional two piece construction, one of the parts is a conventional I-beam section and the other is an elbow shaped column and haunch section, the two being joined by a bolted or riveted splice plate. This is a material improvement but the haunch section still is a cumbersome unit to store and ship. Also, since ditferent builders have different ideas about what the wall height of their building should be (which means that the column portion must be made longer or shorter according to the builders requirements), the factory must maintain a variety of sizes of haunch sections, each size being specially designed and engineered at no little expense.

'and rafter assembly wherein thecolufnn vandfrafter are `separate straight structural members so 'formed as to -permit a stable strong interconnection therebetween which is simple'in construction, modestinsize and requires a lminimum number -of interconnecting bolts or rivets 4therebetween to secure the two members one to the other.

-Another object of the invention is to provide a'column vand 4rafter assembly "as described in the previous parafgraphhaving means to fprevent twisting of the column and the rafter about their longitudinal axes.

Other and further objects of the invention will'appear vinthe course of the following description.

Inthe'drawings, which form` aipart ofthe i'ns'ta'ntspeci- Aiicationand areto be read in i'conjunctiontherewith, *an embodiment of 'theinvention is fshown and, inthe 'various lviews,like ynumerals areused'to indicate like=parts.

Fig. ll iis ka perspective View with parts broken faw'ay showing -a-rigid frame sectional building employing the inventive'column andrafter assembly therein. Fig. -2 is an elevation 'showing the inventive -colu'mn andraftera'ssemblyas mounted'ina typical rigid frame building. l

Fig. 3=isa view'taken along Ythe lines 3-3'of 'Fig f2 inthe direction of the arrows. Fig. 4is a view'taken alo'ng'the lines 4 4 of Fig. 2 in the direction`of the arrows.

Fig-5 is a view taken along the lines 5 5 of Fig. 2 in ythe direction vof the arrows.

Fig. 6 is a view taken along the lines 6-6 of Fig. 2 Y

Referring now to the drawings and more particularly to Fig. l, reference numeral 10 indicates generally 1the flooring for the building, 'which may conveniently be a pouredconcr'ete slab. Around the margin 'of 'the slab is provided a raised curb 10a which is continuous except for a gap Vatthe forwardend providing a sill 10b for the forward door level with the floor of the building. -T he floor or foundation is preferably poured in a shallow excavation conforming in size and shape with the desired dimensions ofthe building, and the curbing 10a is formed in the usual manner by wooden forms which can be knocked'down and removed, once the concrete is set.

Providing the main supporting structure for the side walls and roof vare the arch-like support members 11, spaced at intervals along the length of the building. As is seen in Figs. l and 2, each of the members 11 `rcomprises `two opposed generally L-shaped girders having vertical legs or columns 12 and inwardly extending, upwardly linclined legs or rafters 13. The inner ends of the rafters 13 abut yone another and are secured together in any suitable fashion, for example, by lapped plates 14 (Fig. 2). The lower ends of the columns 12 rest upon and are secured to the curbing 10avof the foundation in a manner to be subsequently described. A series of

diagonal tie rods

15, 16, 17 and 1S, each provided with an intermediate turn buckle 15a, 16a, '17a and 18a, is provided between adjacent frame ymembers 11 for' bringing the members '11 'into parallel relationship.

v Figs. ll and 2 show the preferred manner in which the frame or support members '1'1 are connected v'vithithe 75 foundation curbing 10a. The lower ends of the vertical columns 12 are received in channel-like brackets -19 which have their web portions secured rigidly to the curbing 10a by bolts 20 set therein when the concrete is poured. The lower end of each column 12 is received between the upstanding vflanges of its respective bracket 19 and bolts 21 are provided for securing the two together. It will be noted that the girders which form the frame members 11 are I-shaped in cross section, and that the bolts 21 are received through the cross flanges of the l on opposite sides of the center web.

In assembling the building, the rst step consists of raising the frame members 11, securing them to -the foundation in the fashion just described in connecting the frames with one yanother by means of thetie rods. It will be understood that the length of the building and the internal strength required will dictate the number of frame members 11 that are used. In the illustrated embodiment there are only three, one at each end and one intermediate the ends substantially equdistant therefrom.

Following the assembly and raising of the internal frame structure, the horizontal girts 22, roof purlins 23 and eave members 24 are attached thereto. The girts 22 extend lengthwise of the building on opposite sides thereof 'and are preferably Z-shaped sections secured to the outer flanges of the vertical legs 12 intermediate the upper and lower ends thereof. Flange braces 25 are used to provide lateral support for the inside flange of the rigid frame and a sag rod 26 depends from the eave member 24 to suspend the center section of the girt. It will be understood that girts 22 are secured directly to the vertical legs 12 of the frame members, either by welding or by bolts.

The roof purlins 23 are also preferably Z-shaped in cross-sectionand like the girts span the distance between adjacent frame membersl 11. The ends of the purlins rest upon andare secured in any suitable fashion, such 'a'sby bolts, tothe upper flanges of the rafters 13. Transverse'tie rods 27 are utilized to connect the intermediate portion of adjacent purlins 23 and to maintain them in parallel relationship.

'As isseen in Figs. l and 2, the eave members 24 comprise C-shaped sections which are secured to and spaced outwardly from the outer ends of the rafters 13. The eave`members'24 are bolted by bolts 28 to the rafters.

iIn the illustrated embodiment, the building is particularly suitable for garages or warehouses, and`thus is provided 'at its forward `end with framework adapted'to provide a large door. The door jamb is formed by spaced upright posts 29 which carry at their upper ends a horizontal header 30, connected at its ends to the underside of theinwardly extending rafter of the forward frame member l11. A center support 31 rises vertically from the cross beam to connect with the (only in small'buildings) vertex 'or ridge of the frame member through a horizontal connecting'plate `32. Intermediate horizontal girts 33 are provided betwee'nthe posts and the vertical columns for mounting of the wall panels, as will behereinafter described. It will be evident, however, Ithat vother types of ends may be desirable, depending on the use to which the building is to be put.

The side walls of the building are formed by a plurality of corrugated rectangular panels 34 which are fastened to the framework of the building in the manner shown in Fig. 2. Each panel preferably comprises a at metal sheet having formed therein three spaced'p'arallel corrugations, -a center corrugation and two outer corruga tions which form the outer edges of the panel. An interlocking arrangement between adjacent panels is obtained by nesting the corrugations at the edges'fof'thc panel one within the other'to 'give the appearanceof a continuous single panel arrangement. The nesting corrugtions may be provided with lbolt apertures 'for the amasar insertion of bolts to obtain betweenpanels.

As shown in Figs. l and 2, the length of the side wall panel is preferably equal to the height of the side wall of the building. The upper ends of the side wall panel are bolded to the eave member 24 and the intermediate portion of the panels are bolted to the girt 22. The lowerends of the side wall panel are bolted in like fashion to an angle iron 35 secured on top of and along the outer edge of the curbing a. It will be noted particularly from Fig. 2 that the lower ends of the corrugations are closed by flattening the end of the corrugation against the sheet. The lower terminus of each corrugation along the length and across the width of a building is flattened or crimped in the fashion shown, thus providing a weather-tight connection with the foundation.

The roof of the building is formed in much the same manner as the side walls. As is true in the side walls, the roof panels 36 have interlocking corrugations and are disposed in interlocking side by side arrangement along the length of the building. However, each side of the roof preferably comprises three panel sections, namely, an outer or eave panel 36a having a downwardly curved portion extending beyond the side wall of the building; a flat intermediate roof panel 36h overlapping at its lower end the upper end of the eave panel;` and a one-piece ridge panel 36C having angularly disposed portions extending downwardly from the ridge line of the roof on opposite sides thereof which overlap at their lower ends the upper ends of the intermediate panels. The joints provided by the interlocking corrugations lengthwise of the building and the overlapping relation between adjacent panels from the eave to the ridge line are weather-tight and prevent leakage, even under the most severe conditions. The panels are secured to the frame work of the building (eave members 24 and roof purlins 23) by bolts 37 located at suitably spaced intervals.

It will be noted that'the joint formed by the intersection of the side wall panels with the eave panels is effectively shielded by the downwardly curved portion of the latter. Even in strong winds, snow or rain, it is effectively deected away from the joint and there is little or no possibility of intrusion. Also, by Virtue of the single piece ridge panel, no joint is formed along the ridge line of the roof and leakage is thus impossible in this area.

It will be understood that while in Fig. l only a portion of the building is shown as paneled, in its completed form it is completely covered with the exception of the doors and windows. ln forming the end walls it may be necessary to superimpose an upper panel section over the upper end of the conventional side wall panel to obtain the required height. The upper edge of the upper panel section will of course be cut along a line conforming to the pitch of the roof. To fill the space over the door, pieces of the required configuration can be cut from the basic panel.

Returning to the frame members 11, it will be observed that the depth of the vertical columns 12 increases uniformly from the lower end to the point of contact with the inwardly and upwardly extending rafters 13. Correspondingly, rafters 13 increase in depth toward their outer ends. The tapered configuration of the frame members 11 makes possible the construction of a building in which internal cross beams from wall to wall are eliminated. A calculation of the bending moments through the frame members 11 indicate that the maximum moment is obtained in the heaviest and widest portion of the frame, that is, at the intersection of the vertical columns 12 with the inclined connecting rafters 13. By tapering the depth of the frame members from the area of maximum moment toward the ends a great saving in material as well as weight is attained.

a more rigid connection '6 The column and raft' assembly Referring more particularly now to Figs. 2 through 6 the inventive structure comprises a column and rafter assembly which' forms a portion of an arched support member for rigid frame building. Vertical column 12 has horizontal plate 38 formed on the top thereof with a portion of said plate extending beyond the outer ange of the column. Rafter member 13 is attachable -to the top of the column at its outer end and angles upwardly inwardly whereby to engage at the ridge of the building with an opposite member 13 with its inward end. The column 12 and the rafter 13 are I-beams in cross section. Arportion of the lower l-beam tiange of the rafter 13 is angled from the line of the lower ange to form a horizontal plate 39 to match and engage thehorizontal column plate 3S. The web of rafter 13 extends beyond the outer edge of the column to the vicinity of the outer edges of the column and rafter horizontal plates. Supporting means or gusset 40 may be employed to connect the outwardly extended portion of the column horizontal plate and the outer flange of the column. Continuous flange 41 at the outer end of the rafter joins the rafter flange and the lower rafter horizontal plate to furnish additional strength in the end of the rafter. The continuous flange 41 is normal to the web of the rafter. Bolts 4&2 outside the outer ange of the column and bolts 43, preferably positioned at the inner edge of the column, connect the column horizontal plate and rafter horizontal plate to form an essentially rigid joint therebetween. The column web preferably increases in width upwardly and the rafter web preferably decreases in width inwardly. Angle iron members 2S attached at one end to the interior flange of the rafter and column members and at their outer ends to the girts 22 or purlins 2.3 prevent the rafter and columns from twisting about their longitudinal axesl The frame itself is a rigid structure. That is, the joints at the ridge and eave are rigid and not hinged. In the structural analysis of the building, the points of attachment of the frame to the foundation are treated as though they were hinged. rlhis is not strictly correct, but the narrow width of the Vcolumn base and the small anchor bolts offer little fixation and the concrete foundation prevents lateral movement. So, the frame is essentially a two hinged arch.

There are several forces to which a building is subjected. These are its own weight, snow load on the roof, wind load on the vertical projection of building, etc. For the purposes of engineering analysis, these are resolved into three forces or effects; moment (or bending moment), thrust and shear. The simplest analysis of a rigid frame is that of a dead load, taking into account only the weight of the building itself. A uniformly distributed roof load such as snow merely results in a uniform increase of the various forces. However, a wind load applied to one side of the building results in eccentric loading with a positive moment in the column to which the wind is applied and a negative moment in the opposite column. In the following discussion, dead loads will be considered only.

First considering the moments developed in the various parts of the structure, since the column is pre-` sumed to be hinged at the base, it is free to rotate` at this point and there is no bending moment. Moving up the column, the moment increases uniformly to the knee joint where there is a change of direction into the roof beam. This moment in the column is a negative one with the inside flange of the column under compression and the outside flange of the column under tension. The neutral axis where there is neither compression nor tension runs up the center line of the column. Since the moment varies uniformly from a maximum at the top to zero at the bottom, the column can be correspondingly designed wide at the top and narrow at the bottom. The knee joint is rigid, so the moment developed in the roof beam at this joint must Aequal that;

7 d eveloped in;the-column and must-be-inthe same direction. Starting at the roof beam at the knee joint where -therey is la' rfrafxiin'umriega'tive 'nmenL in" the" progression up the'f'looffb'e'am foward the rid'g'e, themment decreases until it becomes z ero at some'point between the knee Vand the ridge. 'It 1then b'ecomespositive and Are- 'r'nainsjso'until theridge is reached. The neutral axis of the roof b'eam lies 'on or'ne'ar thefce'n't'e'r lline. At, ythe knee jontwhere the'f'orce changes direction, the neutral axisfte'ndstopull in toward the inside Hnge. Although lthe forces ow continuously through this joint, ltheir exact distribution y.depends on the type Aof" joint.

, The thrust 'in 'the colnin'isiinifoi'm and is ldirected downwardly'nto the foundation. lThe th'r'ustinthe-roof bem is directed along .its'axis towar'd`the knee and'incireasl'esunifoxrilyfrom, the"ridge to the knee.

, The s'h'e'ar i'n'the 'column is directed perpendicularly tojgthexis'ofthecolnn Since the base of the column isifixed from lateralin'ovement by lthe`foun`dation bolts, th`e`i`1pper part of the coliimn'tends'to" shear outwardly from the lower part. By convention, this'is called positi'veshear. In the colmnthis shear is uniform. The shea'r'in" the roof beamis directed j'aerp `=.ridic1ilar1y to the axisbfthe'beam and varies uniformly Vfrom a positive 'sliearl'at'the ridge to a"negative shear at the knee. At theridge, the beam is restrained by the joint so the p-art ofthe beam away from the ridge tends'to shear downwardly fro'mthe part near theY ridge. `By convention this is positive. As the knee is approached, t-he opposite condition prevails because the part farthest from the ifidge is restrained by the knee joint. VUnder this conditionuthe part of the beam farthest from the knee ('nearestthe ridge) tends to shear downwardly from"the p'art nearest the knee. By convention, this shear is negative.

` The forces of thrust, shear and moment in the roof beam are transmitted through the knee joint into similar bu't-not equal forces in the column. That is to say, thrust in theroof beam does not equal thrust in the column nor does shearin the roof beam equal shear in the column. As stated previously, the moment of the column at the knee joint equals the moment at the roof beam at 'the same joint.

structurally speaking, then, the inventive assembly comprises a column-and rafter assembly forming essentially a two hinged arch support member for a rigid frame building. The support member includes a pair of vertical columns, the columns under dead load conditions having neutral moment axes running up essentially the center lines 'thereof and a pair of rafter members attached to the tops of the columns'to f-orm rigid knee joints at their outer `ends`and angling upwardly to join at their inner endsV to form a rigid ridge joint. The rafter members under dead load conditions have neutral moment axes running essentially along their center lines. The neutral axes-inthe knee joints lie under dead'l-oad conditions between t-he inner and outer edges of the joints.

Thus when the means which join'the column and afterhorizontal plates together are in part positioned in the portions of the assembly projecting beyond the outside ofthe column ange and in part adjacent the inside Vof the column, a'vertical loading of the rafter tends-to produce a moment so'that the outermost joining rneansr are under tension kand the innermost joining means are in compression. VA horizontal load on the outside face of the column or side wall of the building tends to produce a reversed'rnoment whereby the outside joining means are under compression and the innermost joining means are under tension.

,A Fig. 7 shows a construction illustrating the manner of joining two rafter members 1'3 withl a single column member 12 topermit joinder of the side walls of two rigidv framebuildingsto form a single rigid frame building ofgreaterwidth. I'n this construction, a single unitary, 'preferably nontaper'ed (the momentslof the ltwo buildings cancelone yanother inthis'colu'rn'n) column'lZ is employed having a horizontal plate aixed'tof-the'top thereof?numb'ered'4'4whiehsisupported on eachfside by 'gussets "45. I-bea'm^46 having `Yend --nges 47 1 joining theupper and lower-flanges `thereofiis lixe'dly-attached to column-horizontalplate44'byf-boltsf48. Rafters 13 have horizontal Y-plates 39a running-continuously ywith the lowerflan'ges thereoffandendianges -'41m-joining-the horizontal lrafter plates Yr9a'a'n`d'the upper rafte'rr'l-beam flanges. Bolts 49 and bolts '50,eent`rally and peripherally engage the rafter hbrizbntal'pla'tes39a and'th'eitopfange -of I-beam`46. i

From the foregoingit will beseen'thatthisfinvehtion is lone well adapted' to Fattairi'all of the i ends an'd objects hereinabove set forth, together A'with *other advantages which are obviousand'fwhich-'a're inherenttothe structure.

It will be understood'that-,certain `features 'and subcombinations' are of' utilityAV and may -beemployed without reference tootherfeatures 'and `subcombinations. This is contemplated by and'is :within the scope of the claims.

As many. possible embodimentsrnay'be'made of Xthe invention without departing from'thefseope thereof; it'is to beunderstood that 'all material hereinabove 'set forth or shownin thedrfa'wingsris t'o-vbe'interpreted'was illustrative and not in; a limiting/sense Having thus-#described rny invention,'I claim:

'1. Acol'mn and raftervassembly formingan arched support member for a rigid frame building` comprising a pair l of' at least'lsubs'tantially 'vertical Ycolumns,` a 1 pair of rafterrne'mbersfdetachably'connected to the tops of'said columns 'atx their outer-ends `and-angling upwardly to join attheirinnerends-to frm 'a=ridge, said columns and said rafters lI-beainsfinv cross'fsecti'on, af horizontal plate tixed said fplatesfexten'ding outwardly he'yond'the outer edges offeaehfofsaid columns, a'porticinofl each of the lower I- beam flanges'bf the 'raftersi angled from'the lineof the lower flange to form horizontal plates to match 2andengage vvth'e"horizontaly col'm'n plates, the web-of said rafters extending beyond'tlielfouter anges of 'saidicolumns at least to thevicinit'ylbfthe outeriedges of said plates, and meanscon'r'iec'tingthe column"h`orizontal `plates and'the rafter'horizontalplates t'o form anesse'ntilly rigid joint therebetween. I

'-2. Acolur'rna'nd rafter' assembly 'asV in claim l including support-ing means connecting the-outwardly extending portions of the column horizontal plates and the outer flanges ofthe columns.

3, A column and rafter assembly forming Vessentially a two hinged 'archisupport'membervfor a'rrigid frame building comprising a pair of at least substantially vertical columns, said columns under dead load'conditions having a neutral moment axis running'up'sub'stantially the center line thereof, a pair of rafter members detach- `ably connected to the tops of said columns to form a rigid knee joint at theirouter ends and angling upwardly to join at their inner ends to form a'rigid ridge joint, said rafter members under dead load-conditions having neutral moment axes running essentially along their center lines, said columns 'and said rafters'I-beams in cross section, the neutral axes in the knee-joints between the columns rand the rafters lying under dead load conditions between the inner and outer edges of the joints,a hori- 7 zontal plate fixed to the top of each of said columns,

a portion of each of said plates extending beyond the outer flanges of each of said columns, a portion of each of the lower I-beam flanges of the rafters angled from the line of the lower flanges to form horizontal plates to match and engage the horizontal column plates, the webs of said rafters extending beyond'the outer lianges of the columns at least to the vicinity ofthe outer edges of the column and rafter horizontal plates, and means connecting the columnhorizontal plates and rafter horizontal j plates to-form an' essentially rigid joint therebetween.

4. A column and rafter assembly as in claim 3 wherein the means connecting the column horizontal plates and rafter horizontal plates are positioned on opposite sides of the neutral axes in the knee joints.

5. In a prefabricated building supported on a surface, a curbing raised above said surface and bounding at least a portion of the periphery of the area to form the floor space of the building, a plurality of essentially parallel frame members spaced relative said floor and spanning the width thereof, each frame member comprising a pair of upright columns attached at their lower ends to top surface of the curb and spaced inwardly from the outer edge thereof and a pair of inwardly and upwardly extending connecting rafters joined at their inner ends to form an arch, said columns and rafters I-beams in cross section, panel support members interconnecting adjacent frame members along the length of the building including at least one member on each column and at least one on each rafter, said panel support members xed to the outer surfaces of said columns and rafters `and the column panel support members having their outer edges vertically in line with the outer edge of said curb, substantially horizontal plates fixed to the top of each of said columns, a portion of each of said plates extending beyond the outer flange of its respective column to a position with its outer edge substantially vertically in line with the outer edge of the curb, a portion of each of the lower I-beam anges of the rafters vangled from the line of the lower flange to form substantially horizontal plates to match and engage the horizontal column plates, the webs of the rafters extending to a position substantially vertically in line with the outer edge of the curb, means connecting the column and rafter horizontal plates to form an essentially rigid joint therebetween, a plurality of metal panels secured to the support members to form the side walls and the roof of the building, the side panels secured against the outer face of the curb at their lower ends and lying essentially in contact with the column and rafter plate outer edges and rafter web adjacent their upper ends.

6. A prefabricated building as in claim 5 including a panel support member C-shaped `in cross section fixed to the outer edge of the upper flange of each of the rafters, the closed face of the C substantially vertically in line with the peripheral edge of the curb whereby the upper inner face of the side panels lie thereagainst.

7. A building as in claim 6 wherein the side panel upper edges are substantially in line with the top of the C member and the top panels overlie the side panels.

8. A building as in claim 5 including means cooperating between the inside anges of the columns and the column panel support members to prevent the columns twisting about their longitudinal axes.

9. A building as in claim 5 including means cooperating between the inside flanges of the rafters and the rafter panel support members to prevent the rafters twisting about their longitudinal axes.

References Cited in the lile of this patent UNITED STATES PATENTS FOREIGN PATENTS Canada Apr. 26, 1955