US3092221A

US3092221A - Metal roof-supporting construction

Info

Publication number: US3092221A
Application number: US832293A
Authority: US
Inventors: Robert L Parsons; Grover H Bays
Original assignee: PARKERSBURG AETNA CORP
Current assignee: PARKERSBURG AETNA CORP
Priority date: 1959-08-07
Filing date: 1959-08-07
Publication date: 1963-06-04
Anticipated expiration: 1980-06-04

Description

June 4, 1963 R. L. PARSONS ErAL 3,092,221

METAL ROOF-SUPPORTING CONSTRUCTION Filed Aug. 7, 1959 2 Sheets-Sheet 1 ATTORNEY June4, 1963 R. L. PARSONS Erm.

METAL RooFsuPPoRTING CONSTRUCTION 2 Sheets-Sheet 2 Filed Aug. 7, 1959 M5 mw 2 L m w 0 Dn M B. H E W. e Q

A ORNEY United States Patent O 3,092,221 METAL ROF-SUPPRTING CGNSTRUCTION Robert L. Parsons and Grover H. Bays, Parkersburg, W. Va., assigner-s to Parkersburg-Aetna Corporation, Parkersburg, W. Va., a corporation of West Virginia Filed Aug. 7, 1959, Ser. No. 332,293 6 Claims. (Cl. 189-36) This invention relates to a metal roof-supporting construction and has primarily to do with the means for connecting the purlins to each other and to associated elements of a metal building.

An important object of the construction is to provide means for tying adjacent roof purlins to each other to prevent them from deflecting in the plane of the roof while erecting and to help take the horizontal cornponcnt of load such as snow and Wind, in the iinished building construction.

A further obiect is to provide a no fel combination of purlins and purlin ties which so function that tension loads are carried throughout the purlin ties from one side of the building to the other side thereof.

A further object is to provide novel means for connecting the purlin ties on opposite sides of each purlin to each other through the purlin to prevent deection of the purlin in the plane of the roof.

A further object is to provide among the purlin ties one which extends across the ridge of a roof to transfer tension loads between opposite sides of the roof.

A further object is to provide such a construction wherein the novel connection of the purlin ties to each other, in combination with the tie extending across the ridge of the roof, so functions that loads or forces in the planes of the roof will be transferred from the roof covering to one or more purlins which, in turn, will bear against shoulders of purlin ties to be transferred through the connection of such ties to higher purlin ties, thus distributing tension loads.

More specically, a further object is to provide novel means for so connecting adjacent purlin ties through a purlin therebetween as to overcome a tendency of the purlin to turn or otherwise be displaced from normal position.

A further object is to provide such a combination of purlin and purlin ties extending from the ridge of a roof to points spaced from opposite eave struts or equivalent constructions and to connect the eave struts to the adjacent purlins by threaded sag rods, thus preventing dispiacement of the eave struts and permitting the mounting of the latter in straight lines.

A further object is to provide an arrangement of purlin ties relative to intervening purlins having webs perpendicular to the plane of the adjacent portion of the roof; to connect adjacent purlin ties through the purlin web by the use in each case of a single bolt, and to provide purlin ties having, in edect, shoulders engaging the web of the purlin to provide bracing of the top and bottom ilanges of the purlins.

Other objects and advantages of the invention will become apparent during the course of the following description.

ln the drawings we have shown one embodiment of the invention, In this showing:

-FlGURE l is a partial plan View, largely diagrammatic, of a portion of a roof-supporting structure embodying the present invention;

FGURE 2 is an end elevation of the same;

FIGURE 3 is a section taken substantially on line 3 3 of FIGURE l, parts being broken away;

FIGURE 4 is a detail fragmentary sectional view 0n line 4i-4i of FIGURE 3;

ice

IFGURE 5 is a similar view on line 5-5 of IFIGURE 3;

FIGURE 6 is a similar View on line 6 6 of FIG- URE 3;

FIGURE 7 is a perspective view of ka purlin tie extending horizontally at the ridge of the roof structure;

FGURE 8 is a similar view of one of the other purlin ties;

FIGURE 9 is a side elevation of one of the purlin sections; and

-FlGURE 10 is a perspective of a connection employed for securing each end of the ridge purlin tie to adjacent pnrlin ties.

Referring to FlGURE 1, there are shown in broken lines opposite columns 1t) of a building structure, columns at each side of the structure being connected by any suitable type of girts l1. The columns support girders l?. shown in the present instance of the rigid bent type. lt will Ibecome apparent, however, that the present invention is not limited to use with a girder of this type, since the girder may be of other types, for example, the top chord of a truss.

At each side of the structure is diagrammatically shown in FIGURE l an eave strut 14, and this particular element, extending longitudinally of the building, may be of any desired or suitable type. Extending longitudinally of the building and bolted or otherwise secured to adjacent girders 12 are a plurality of purlins, each indicated as a -whole by the numeral l5. The number of these purlins rWill depend, of course, on the span of the root, and three of the purlins have been shown in FIGURE 3. Each purlin comprises a veb 16 perpendicular to the plane of the roof and provided at its upper longitudinal edge with a yharige 17 parallel to the plane of the root" and a down-turned ange l parallel to the web le. The bottom of each purlin comprises a ilange 19 parallel to the slope of the roof, and it is these flanges which are secured to the girders, such anges being directly seated on the girders, as will be apparent in `FIGURE 2. The flanges 19 terminate at their edges remote from the webs 16 in ilanges 2i) corresponding to the ilange 18 and arranged parallel to the webs 15. The web of each purlin is slotted as at 22 intermediate and perpendicular to its longitudinal edges, as shown in FIGURE 9, for a purpose to be described.

lt will be apparent that the purlin sections 15 extend longitudinally of the building and the ends of these sections are suitably bolted together, preferably in overlapping relationship (not shown) over the top flanges of the girders 12, thus providing in eect continuous purlins from end to end of the building. Two of the purlins, indicated as a whole in FIGURE 2 by the numeral 24 and identical with those described, are arranged on opposite sides and slightly spaced from the ridge of the roof. A purlin tie 25 of the type shown in detail in FGURE 7 extends between the purlins 24. Such tie has squared ends and includes a web portion 26 and longitudinal flanges 27 which preferably diverge slightly from each 'other away from the web 26. Each end of the web 26 of each purlin tie 25 is provided centrally of the width thereof with a bolt opening 2.8. The purlin tie 25 is tied to the next adjacent purlin tie outwardly of the purlins 24 in a manner to be described.

The purlins at each side of the ridge of the roof are equidistantly spaced from each other as shown in FIG- URE 2, such arrangement being preferred so that the purlin ties extending between adjacent pairs of purlins may be identical in the interest of economy in manufacture. Between each adjacent pair of purlins at opposite sides of the ridge is arranged a purlin tie or the type shown in FIGURE 8 and indicated as a whole by the 3 Y numeral 30. Each such purlin tie is similar in construction to the tie 25, being provided with a web 31 and upper and lower flanges 32, preferably slightly diverging from each other away from the web 31. Each of the purlin ties 3i?, of course, is longer than the purlin tie 25 land has the anges at one end thereof cut away as at 33 to form shoulders fora purpose to be described. The .cutting-away of the flanges 32 leaves the web 31 with a tongue or projecting web portion 34 having a bolt opening 35 therein, the web 31 at the opposite endof the tie being provided with a similar bolt opening 36. Each of the tongues 34 projects through one of the slots 22 in the adjacent purlin web 16 with the shoulders 33 abutting the web 16. 'I'he'right-hand end of the next lower purlin tie, as viewed in FIGURE 8, has the flange portion thereof forming shoulders abutting the opposite side of the .purlin web 16. The projecting tongue 34 fits within the channel of the next adjacent purlin tie, being equal in width to the space between the flanges 32 adjaf cent the web 31 to provide a rigid joint between the purlin ties at opposite sides of each purlin to prevent any rocking movement lbetween adjacent purlin ties in the plane of their webs 31. A bolt 3S secures each projecting tongue 34 to the adjacent end of the next adjacent purlin tie, the bolt'38 projecting through the bolt opening 35 of the tongue 34 and through the bolt opening of the web of the next adjacent purlin tie, as will be apparent in FIGURES 3 and 4.

At each side of the ridge of the roof, the purlin tie adjacent each of the purlins 24 has -its squared end (the right-hand end in FIGURE 8) abutting the web 16 of such purlin. A T-shaped connecting plate 49 (FIGURES 3 and :140) has its head portion 41 provided with bolt openings 42, one of which receives a bolt 43V to secure it against the outer face of the web 26 of the adjacent end of Ithe tie 25. The shank 45 of the connection 41 projects through one of the slots 22 of the adjacent pur-lin web 16, and such shank corresponds in shape and size to each of the tongues 34 to lie within the channel of the adjacent purlin tie 3i). The shank 45 has a bolt opening 46 Vadapted lto register with the bolt iopening 36 of the adjacent purlin tie 30, and a bolt 47 connects these elements together, as shown in FIGURES 3 and 6.

As previously stated, the purlin ties 30 are preferably identical to each other in the interest of economy in manufacture. Therefore, it seldom occurs that the space between the outermost purlin at each side of the roof and the eave strut 14 is equal to the space between adjacent pairs of purlins. Thus it is impracticable for this reason to use a purlintie between each eave strut and the adjacent purlin, and it is also impracticable for an additional reason to be referred to.

Each eave strut 14 may be of the cross-sect-ional type shown in FIGURE 3, terminating at the top thereof in a depending flange 49 at a slight angle to the vertical, as shown. A sag rod 50, threaded at both ends, projects through the flan-ge 49 and has a nut 51 threaded thereon. 'I'he other end of the sag rod 50 (FIGURE 5) projects through one ange 52 of an angle rail 53, the other flange 54 of which seats against the web 16 of the adjacent purlin 15. Within ythe ange 52. a nut 55 is threaded on the sag rod 50'. The next adjacent purlin tie 30 has its tongue 34 projecting through the adjacent slot 22 of the web 16 and bolted as at 56 to the flange 54. rIhe free end of the ila-nge 54 forms, in effect, a shoulder engaging against the adjacent face of the web 16, while Ithe shoulders 33 of the flanges 32 of the next purlin tie 30 seat against the opposite face of the web 16. Such web is arranged between engaging shoulders in the saune manner as the remaining purlin webs 16 are engaged by adjacent end portions of adjacent purlin ties 31. Thus the sag rod 50 and its angle rail 53 constitute, in eiect, a purlin tie. Similarly, each purlin tie 25 (FIGURES 3 and 7) and its associated tie plates 40 constitute a purlin tie connected lbetween the webs of the purlin-s 24.

Operation inserted in the next 4webs 16 of the adjacent purlins 15,

whereupon the next purlin ties 30 will be placed in position and bolted to the tongues 34 of the preceding purlin ties as at 38. This procedure is followed throughout successive purlins until the lowermost purlins at opposite sides of the roof are in position. The latter purlins are then xed with respect to the remaining structure by bolting the tongue 34 of the adjacent tie 30 to the flange 54 (FIGURE 5) as at 56. The sag rod 50 performs an important function in the structure. It is desired, of course, that each eave strut 14 be maintained straight, and due to manufactuning tolerances, etc., there will be some variation in the distance from each iange 52 to the ange 49 of the adjacent eave strut. By employing the sag rod 50, the nuts 51 and 55 may be suitably tightened to take up any slack between the elements and to straighten .the eave strut 14 at each side of the building. After the assembling has been completed as described, the roof coveringshee-ts are placed over the flanges 17 and secured in position. It will be noted that the sloping top of the eave strut 14 in FIGURE 3 lies in the plane of the purlin anges 15 to support the outer edge portions of the roof covering sheets.

Each sag rod is a tension member and prevents the eave strut from spreading away from the adjacent purlin due to any load directed toward the eave in the plane of the roof. Moreover, 'tension in either sag rod will place in tension the .purlin ties entirely across the building, such tension being transmitted through

bolts

56, 38, 47 and 43. The equal spacing of the purlins permits the manufacture of quantities of identical purlin ties for predetermined roof loadings. The use of the sag rod has the additional advantage of eliminating the necessity of using a purlin tie between Veach eave strut 1'4 and the adjacent purlin and also eliminates the problem which would be involved in connecting such elements together.

The equal spacing of the purlins will vary with diier` ent roof loadings depending upon the strength of the roof covering. For example, some roofs may be designed for 20 pounds per lsquare foot of snow load and others for 30 pounds per square foot. With the same roof covering, the purlins will have to be spaced closer. for 30-pound loading than for 20-pound loading, as will be apparent. In each case, however, the purlin spacing will be kept equal from the ridge toward the eave by means of identical purlin ties. These ties are primarily tension members, but will withstand sorne vcompression and bending.

The tendency for the purlins to deflect or bend in the plane of the roof will be prevented by the horizontal purlin tie at the ridge and the sloping ties at either side of the ridge. The loads or forces in the plane of the roof will be transferred from the roof covering to the purlins which, in turn, will bear `against the anges of the squared ends of the purlin ties (the right-'hand end n- FIGURE 8) and tension loads will be transferred through the tongues 34 of the next higher purlin ties.

It will be noted that the reduced ends or tongues 34 and the width of the shank 45 (FIGURE 10) are the same as the inside dimension of the purlin ties between the edge anges thereof. Accordingly, when the

bolts

38 and 47 are tightened, the ends 34 or 45 will be wedged in the channels of the purlin ties, thus preventing rocking of the purlin ties in the planes of their Webs. The shoulders formed on the ends of the purlin ties bear against the webs 16 of the purlins and accordingly tend to resist the slightest rotation or rocking of the purlin webs.

The degree of resistance to rotation `afforded by the bearing of the shoulders of the purlin ties on the purlin webs is dependent upon the depth of each tie as well as proper orientation of the tie. In the present construction, the depth of each tie is sucient to overcome purlin rotational tendencies without overstressing the shoulders of the purlin ties which are in bearing. Moreover, the orientation of each purlin tie is with the web of the tie perpendicular to the longitudinal center line of the adjacent purlin, this being the most etective arrangement of parts for maximum resistance to rotation of each purlin. The location of each purlin tie with its end centrally of the width of each web 16 provides lateral bracing for the top and bottom anges of the purlins.

The present construction not only resists loads from the roof covering due to snow, wind and erection, but also resists the weight of workmen or other loads on the purlins between the girders. Such loads cause undue rotation and bending of the flanges of the purlins. The purlin ties hold the purlins in alinement and prevent rotation, to facilitate the installation of the roof covering and provide increased safety for workmen.

It is to be understood that the form of the invention shown and described is to be taken as a preferred example of the same and that various changes in the shape, size, and arrangement of the parts may be made as do not depart from the spirit of the invention or the scope of the appended claims.

We claim:

1. In a roof construction wherein the roof slopes `downwardly in opposite directions away from a ridge, a plurality of purlins arranged at each side of said ridge and spaced lfrom and parallel to each other and to said ridge, two of said purlins being arranged at opposite sides of said ridge and equidistantly spaced therefrom, said two purlins having webs perpendicular to the respective slopes of the roof and provided with sets of slots transversely of such webs, purlin ties connecting adjacent pairs of said purlins, horizontal purlin ties associated with each of said slots and extending between said two purlins, all of said purlin ties having webs lying -in vertical planes, a tongue at each end of each horizontal purlin tie forming a continuation of the web thereof projecting through and fitting one of said slots, and means connecting said tongues to the respective purlin ties at the remote sides of said two purlins, the ends of the webs of said purlin ties at the remote sides of said two purlin .ties abutting the webs thereof offset to one side of the respective slots.

2. A construction according to claim 1 wherein each purlin tie extending between said two purlins is horizontal and comprises a horizontal purlin tie body and a T-shaped plate connected to each end of such body having a head portion connected to the web of said purlin tie body and having its shank constituting the tongue of the last-mentioned purlin, the heads of Said plates abutting the adjacent sides of said two purlins.

3. in a root construction wherein the roof slopes downwardly in opposite directions away from a ridge, a plurality of purlins arranged at each side of said ridge and spaced from and parallel to each other and to said ridge, two of said purlins being arranged at opposite sides of said ridge and equidistantly spaced therefrom, each purlin having a web perpendicular to the adjacent slope of the roof and provided with spaced slots transversely of such webs, each slot in each purlin web lying in `a common plane with slots in the other purlin webs, purlin ties -aI- ranged between each adjacent pair of purlins and each provided with a web lying in a perpendicular plane and edge anges, the purlin ties between said two purlins being horizontal and each having tongues at opposite ends thereof forming continuations of the web thereof projecting through and fitting slots in the respective purlins of said two purlins, each of the other purlin ties having a tongue in the plane of the web thereof at the end thereof remote from said two purlin ties projecting through and litting one of said slots and overlying the web of the next adjacent purlin tie, and bolts passing through each tongue and the purlin tie web which it overlies, adjacent ends of each adjacent pair of purlin ties at each slope of the web having shoulders engaging the purlin web therebetween.

4. A construction according to claim 3, wherein the anges of each purlin tie project from the same side of the web thereof whereby each purlin tie is of channel section, each of said tongues being of a width equal t0 the distance between said flanges to be engaged thereby to prevent relative rocking of ladjacent purlin .ties in the planes of the Webs thereof.

5. In a roof construction wherein the roof slopes downwardly in opposite directions away from a ridge, a plurality of purlins larranged `at each side of said ridge, and spaced from and parallel to each other and to said ridge, two of said purlins being arranged at opposite sides of said ridge and equidistantly spaced therefrom, all of said purlins having webs perpendicular to their respective slopes of the roof and provided with sets `of slots transversely of such webs, the slots of each set lying ina common vertical plane, purlin ties connecting adjacent pairs of purlins at each side of said ridge, horizontal purlin ties associated with the slots of said two purlins, said horizontal purlin ties being connected to the adjacent ends of the adjacent purlin ties through the -slots in said two purlins, each of the remaining purlin ties having a squared end engaging the web of the adjacent purlin, the other end of each such purlin tie having a tongue forming -a continuation of its web and projecting through the adjacent slot in the adjacent purlin, and overlying the web of the next adjacent purlin tie, each tongue tting the associated slot and being of a width less than the width of the web of which it forms a continuation, whereby portions of each such web beyond the edges of the associated tongue seat against the web of the associated purlin, and means xing each tongue to the purlin tie web which it overlies whereby said purlin ties act in eifect as `a continuous tension member from side to side of the roof.

6. A construction according to claim 5, wherein each purlin tie is provided with longitudinal edge flanges projecting from the same side of the web thereof, whereby each purlin tie is of channel section, each of said tongues being of a width equal to the distance between said anges to be engaged thereby to prevent relative rocking of adjacent purlin ties in the plane of the webs thereof.

References Cited in the le of this patent UNITED STATES PATENTS 1,225,727 Brogden May 8, 1917 1,843,356 Carlough Feb. 2, 1932 2,549,816 Johnson Apr. 24, 11951 2,689,630 Drury Sept. 21, 1954 2,692,033 Jayness Oct. 19, 1954 2,722,901 Johnson et al, Nov. 8, 1955 2,815,831 Hield et al Dec. 10, 1957 2,871,997 Simpson et al Feb. 3, 1959 2,903,z104 Brown Sept. 8, 1959 FOREIGN PATENTS 434,281 Italy Apr. 24, 1948

Claims

1. IN A ROOF CONSTRUCTION WHEREIN THE ROOF SLOPES DOWNWARDLY IN OPPOSITE DIRECTIONS AWAY FROM A RIDGE, A PLURALITY OF PURLINS ARANGED AT EACH SIDE OF SAID RIDGE AND SPACED FROM AND PARALLEL TO EACH OTHER AND TO SAID RIDGE, TWO OF SAID PURLINS BEING ARRANGED AT OPPOSITE SIDES OF SAID RIDGE AND EQUIDISTANTLY SPACED THEREFROM, SAID TWO PURLINS HAVING WEBS PERPENDICULAR TO THE RESPECTIVE SLOPES OF THE ROOF AND PROVIDED WITH SETS OF SLOTS TRANSVERSELY OF SUCH WEBS, PURLIN TIES CONNECTING ADJACENT PAIRS OF SAID PURLINS, HORIZONTAL PURLIN TIES ASSOCIATED WITH EACH OF SAID SLOTS AND EXTENDING BETWEEN SAID TWO PURLINS, ALL OF SAID PURLIN TIES HAVING WEBS LYING IN VERTICAL PLANES, A TONGUE AT EACH END OF EACH HORIZONTAL PURLIN TIE FORMING A CONTINUATION OF THE WEB THEREOF PROJECTING THROUGH AND FITTING ONE OF SAID SLOTS, AND MEANS CONNECTING SAID TONGUES TO THE RESPECTIVE PURLIN TIES AT THE REMOTE SIDES OF SAID TWO PURLINS THE ENDS OF THE WEBS OF SAID PURLIN TIES AT THE REMOTE SIDES OF SAID TWO PURLIN TIES ABUTTING THE WEBS THEREOF OFFSET TO ONE SIDE OF THE RESPECTIVE SLOTS.