Skylight Structure

Abstract

A skylight structure is formed with condensate channels at the upper portions of the purlins and rafters adjacent glazing panels supported by them. Preferably, the condensate channels and the means for interconnecting the purlin and rafters are concealed. The preferred structural members used as rafters and purlins have hollow closed tubular bodies.

Description

This invention relates to a skylight structure having purlin and rafter structural members which support glazing panels of uninsulated glass, plastic acrylic or the like.

Transparent or translucent domes or skylight structures of various kinds are now used in shopping centers, buildings, libraries, swimming pool structures and the like. Such structures cover substantially large surface areas with the rafters and purlins joined to form a grid or skeleton framework for supporting marginal edges of the glazing panels. Preferably, such structures are constructed of lightweight metal purlins and rafters joined into a rigid and strong skeleton to stand loads applied to wide surface areas of the glazing panels. Additionally, as disclosed in Schultz et al. U.S. Pat. No. 3,488,899, the external sides of the outside glazing panels in a skylight structure may be cooled by a cold outside atmosphere with the result that the interior surfaces of the panels may be cooled to a temperature sufficiently lower than the temperature of the air in the building that water vapor carried by the inside air condenses on the interior surfaces of the glazing panels and/or framework. This internal condensate is collected along the purlins and rafters of the structure in condensate channels or gutters and directed to discharge at a weep hole, an outside gutter or a sewer. Also, some moisture on the exterior of the glazing panels may leak or bypass a glazing seal or bypass along a fastener and this bypass moisture is collected in moisture bypass channels which discharge into the gutter or weep hole.

The provisions of condensate channels and bypass moisture channels on purlins and rafters has heretofore been generally at the expense of the neatness and an uncluttered look for the purlins and rafters. Also, where condensate is delivered from the purlin moisture collecting channels to rafter moisture carrying channels, the interconnection between purlin and rafters is complicated by the necessity to provide the condensate flow paths while maintaining adequate mechanical interconnections. As a result, the mechanical interconnections often were made with exposed connectors and fasteners which detracted from the aesthetics of the structure. Moreover, the bypass moisture channels and condensate channels were at different levels in the purlins; and sometimes a downward flow of by pass moisture along the rafter caused a back flow of moisture into the lower condensate channel of the purlin. Such a back flow condition is to be avoided.

Accordingly, an object of the present invention is to provide an improved skylight construction having a clean uncluttered look and an efficient moisture removal system.

These and other objects and advantages of the present invention will become apparent from the following detailed description taken in connection with the accompanying drawings in which:

FIG. 1 is a diagrammatic perspective view of a skylight structure in which the present invention may be embodied;

FIG. 2 is an enlarged, fragmentary, sectional and perspective view of prior art purlins and rafters supporting glazing panels and having a moisture removal system;

FIG. 3 is another perspective view of the prior art structure shown in FIG. 2;

FIG. 4 is an enlarged, fragmentary, sectional and perspective view illustrating purlins and rafters arranged in a skylight structure and embodying the present invention;

FIG. 5 is a cross-sectional view taken substantially along the line 5--5 of FIG. 4;

FIG. 6 is a diagrammatic exploded view of the purlins and rafter of FIG. 4 showing the manner of interconnection therebetween;

FIG. 7 is a sectional view taken substantially along the line 7--7 of FIG. 6 but with the purlins connected to the rafter;

FIG. 8 is a fragmentary perspective view illustrating another embodiment of the invention for a double glazed skylight construction;

FIG. 9 is another fragmentary, partially exploded, perspective view of the structure of FIG. 8;

FIG. 10 is a fragmentary cross-sectional view of the structure of FIG. 8 showing purlin and rafter interconnections; and

FIG. 11 is a cross-sectional view taken substantially along the line 11--11 in FIG. 10, but with the rafter inclined.

As shown in the drawings for purposes of illustration, the invention is embodied, very generally, in a skylight structure 11 which may be used in overhead domes in various kinds of buildings in which a roof or a portion of a roof is formed with glazing panels 12 usually of transparent, tinted or translucent glass or of a plastic such as an acrylic plastic. The glazing panels 12 are supported along marginal edges 15 thereof in a framework 14 of structural members comprising horizontally extending purlins 16 and vertically extending rafters 17.

In prior art skylight structures such as those illustrated in FIGS. 2 and 3, the framework 14a is cluttered in its appearance by the exposed connectors 18a and exposed nuts and bolts 19a joining purlins 16a to rafters 17a. Condensate formed on glazing panels 12a is collected in condensate channels 21a formed by a wide bottom flange 23a projecting laterally from and on opposite sides of a central upstanding web 25a. Condensate is also collected in similar rafter condensate channels 27a formed by a wide bottom flange 29a projecting laterally from and on opposite sides of a central upstanding web 31a on the rafters 16a. These prior art rafters 16a and purlins 17a have upper transverse flanges 33a and 35a, respectively, projecting laterally from their respective central webs resulting in an I beam cross-sectional appearance for the rafters 17a and purlins 16a.

In these prior art frameworks 14a, the bottom flanges 23a of the purlins are disposed above the bottom flanges 29a of the rafters; with ends 37a thereof spaced from rafters 31a to allow condensate to flow over the flange ends 37a and to drop into the underlying rafter condensate channels 27a. Additionally, any moisture leaking past, i.e., by-passing, glazing seals 38a or fasteners 39a for fastening glazing bars or caps 40a to the purlins 16a is collected in internal bypass channels 41a at the top of the purlins 16a and carried to the ends of the purlins and allowed to flow down along the rafter's central web 31a into the rafter condensate channel 27a. In a similar manner, moisture by-passing rafter glazing seals 42a or bypassing fasteners for its glazing bar or cap 43a was collected in internal bypass channels 44a on the rafters 17a. Where considerable bypass moisture was present, it could flow down along the rafter web 31 a and cause a back flow of moisture into a purlin condensate channel 21a. Thus, the bypass moisture and condensate moisture were collected at different levels in the purlins and then deposited in the rafter condensate channels 27a.

Also, in the prior art frameworks 14a, exposed right angle connectors 18a and bolts 19a are used to fasten the intersecting purlins 16a to the rafters 17a. These connectors, bolts, and nuts, as well as the spaced top flanges 33a, 35a and bottom flanges 23a, 29a, contribute to an overall cluttered appearance to the structure which is desired to be overcome. Also, while the bypass and the condensate moisture are generally collected, the condensate channels are objectionable to some people and for certain applications as being too wide and too exposed to view.

In accordance with the present invention, the skylight structure 11 is formed with a clean, neat and uncluttered appearance with closed tubular-shaped purlins 16 and rafters 17 (FIG. 4) having hollow interiors with small condensate channels 21 and 27 being formed in the upper portions of the purlins 16 and rafters 17 adjacent the glazing panels 12. More specifically, the purlins and rafters 16 and 17 derive sufficient rigidity and strength from their tubular bodies 45 and 46, usually formed of extruded aluminum, and have thereon hidden condensate channels 21 and 27, as will be explained in greater detail. Also, the purlins 16 are preferably interconnected to the rafters 17 by a hidden, i.e., non-exposed interconnection, rather than by the exposed bolts 19a and connectors 18a used with prior structure shown in FIGS. 2 and 3.

Preferably, the condensate channels 21 in the purlins 16 are disposed adjacent to and extend longitudinally of the purlins with a pair of glazing supports 47 also carried along the upper portions of the purlins 16 upon which rest first marginal edges 15 of a pair of adjacent glazing panels 12. The purlin condensate channels 21 and bypass channels 94 are at substantially the same level. Similarly, a pair of glazing supports 48 are disposed adjacent to and extend longitudinally of the rafter 17 with bypass channels 94 and 94a adjacent the level of the rafter condensate channels 27. Preferably, outer sides of the purlin condensate channels 21 are formed as extensions of and coplanar with vertical, side walls 49 of the tubular body and extend to upper edges 51 positioned relatively close to the glazing panels 12. In a like manner, the outer sides of the rafter condensate channels 27 are formed as extensions of and coplanar with vertical side walls 50 of the rafter and extend to upper edges 52 adjacent the glazing panels 12. Thus, the presence of the condensate channels will not be readily, if at all, noticeable from below.

Also, to enhance the appearance, as viewed from beneath, the purlins 16 and rafters 17 are preferably interconnected by hidden interconnector means 53, as best seen in FIG. 6. The preferred interconnector means 53 between the purlins 16 and rafters 17 further comprises forming a curb or projection 54 on an end 55 of a purlin 16 to seat in a notch 57 formed in outer rafter condensate channel walls 58. In this instance, ends 59 of the purlin side walls 49 abut the vertical side walls 50 of the rafters 17. To prevent separation of the purlin curbs 54 from the rafter while still allowing clearance and tolerances for construction, the interconnecting means 53 further comprises retaining pin means 61 comprising pins 63 and 65. The pins 63 are secured in apertures in the purlins 16 and project downwardly into the rafter condensate channels 27 to abut the outer condensate channel walls 58 if the purlins 16 should tend to separate from the rafters 17. Longitudinally extending pins 65 may be inserted into holes or spaces formed in the purlins and rafters to extend therebetween to hold the purlins against shifting or lifting relative to the rafters. Thus, the hidden notching and hidden pins interconnect the purlins 16 and rafters against separation and large shifting movements relative to one another.

Referring now in greater detail to the individual elements of the skylight structure 11, the illustrated purlins 16 and rafters 17 are preferably formed of lightweight metal extrusions, for example of aluminum, with the closed tubular bodies enclosing a hollow interior space 73. In addition to the vertical side walls 49 and 50, the purlins 16 and rafters 17 each have a bottom wall 75 spanning a pair of side walls and joined thereto at integral corners 77. Also, each purlin 16 and rafter 17 has a top wall 79 which is disposed substantially parallel to the bottom wall 77 and which also is joined to the upper ends of the vertical side walls at right angled integral corners. In this instance, the purlin has a generally rectangular cross-sectional shape with the top and bottom walls 75 and 79 being longer than the vertical side walls 49.

Referring now in greater detail to the purlin 16, the condensate channels 21 each are defined by an open top, an outer vertical side at condensate wall 58, a bottom side 81 and an inner vertical side at a vertical wall 83. In this instance, the condensate channels are formed with a generally rectangular cross section. The inner channel wall 83 is spaced from ends 37 of the purlins 16 supported on the rafter and is parallel to the outer channel wall 58 and extends upwardly slightly above the upper edge 51 of the condensate outer wall 58 to terminate at a horizontal surface 85 of an extruded body 86 for the glazing support 47.

The marginal edges 15 of the glazing panels 12 are spaced slightly above the open tops of the purlin condensate channels 21 and inwardly thereof to purlin-supporting, glazing strips 87. The latter each have a lower spline shaped section 89 inserted into a complementary cross section slot 91 in the extruded body 86 and rest on the top surface 85 thereof. The upper edges of the glazing strip 87 are formed with sawtooth edges which are flattened slightly by the pressure from the exterior clamping or glazing bar 40 to provide a weathertight seal against the passage of moisture between the glazing panel 12 and the glazing strip 87. The preferred glazing strips 87 are formed of neoprene to provide resilient support surfaces which will provide a weathertight seal with the glazing panels. The purlin glazing strips 87 space interior sides 93 of the glazing panels 12 slightly above upper edges 51 of the condensate channels 21 so that condensate may flow along the glazing panels to the vertical sides of the glazing strips 87 and then flow down along the inner channel wall 83 and into the condensate channels 21 for delivery to the rafter condensate channels.

The marginal portions 15 of the glazing panels 12 have vertical edges 92 which are abutted against and cushioned by a glazing block 93 made of a suitable resilient material such as neoprene carried in a groove 94 on the top portion of the purlin 16. More specifically, the glazing block 93 is generally rectangular in cross section and extends longitudinally the length of the purlin and extends vertically above the glazing strip 87 and between the edge 92 of the glazing panel and one of a pair of upstanding cap-securing walls 95 and 96. While the purlin 16 shown in FIGS. 4 and 5 has only one glazing block 93 on the uphill side of the purlin, a second glazing block 93 may be inserted into the other empty groove 94.

The grooves 94 function to collect and to convey external water which has leaked into the skylight. A center groove or channel 94 functions to collect and to convey external water which may have leaked past fastener 39. The grooves 94 and 94a thus serve as a by-pass means to collect and transfer by-pass water.

Th glazing cap 40 is located relative to the purlin 16 and is secured to a pair of upstanding, cap-securing walls 95 and 96 which extend longitudinally of the purlin with upper edges thereof extending above the glazing panels 12 to project between a pair of longitudinally extending, depending flanges 97 formed on the inwardly facing side of the glazing cap. More specifically, lower marginal portions of the cap flanges 97 abut the outer sides of the cap-securing walls 95 and 96 and center the cap relative to the purlin 16 and edges of the glazing panels 12. The width of the space between the cap securing flanges 95 and 96 is less (at least at the lower portion of the space) than the outside diameter of the threads on cap screw shanks 99 to allow the self-tapping screws 39 to screw into the cap-securing walls 95 and 96. Suitable openings are formed in the glazing caps 40 to allow the screw shank to project down and to screw into the walls 95 and 96 as the cap screw is turned. The preferred glazing cap 40 is formed of extruded aluminum and covers the area between adjacent glazing panels 12.

On the underside of the glazing caps 40 are a pair of resilient glazing seals 101 which are compressed against the exterior side of the glazing panels 12 to provide a weatherproof seal along the exterior of the glazing panels. The glazing strips 101 in glazing are similar to and opposite to the glazing strips 87 carried by the purlins 16 and hence will not be described in greater detail.

Turning now in greater detail to the rafter 17, it has a glazing cap 43 generally similar to the glazing cap 40 in that it has a pair of depending longitudinally extending flanges 97 for abutting against the upper marginal edges of a pair of similar upstanding cap locating and securing walls 95 and 96. The glazing cap 43 for the rafter also has a pair of glazing strips 101 for sealing against the other exterior margins of the glazing panels 12 and holding them against the underneath pair of glazing strips 87 carried by the rafter 17 in glazing strip bodies 86. As in the purlins, glazing blocks 93 are carried in the grooves 94 at the top wall of the rafter 17 to abut edges 92 of the glazing panels 12. As the glazing strips 87, glazing blocks 93, and cooperation of the flanges 95 and 96 with the glazing cap 43 are substantially the same in structure and function for both the rafters 17 and the purlins 16, they will not be described in any greater detail.

The condensate channels 27 for the rafter 17 are formed with open tops and extend downwardly to a greater depth than the purlin condensate channels 21 and have a greater capacity to carry moisture than the purlin condensate channels from which they collect moisture. The bottom side of the condensate channel 27 is formed by extruded wall 105 which is generally horizontally extending and projects at right angles and inwardly from an integral connection with the outer condensate side wall 58. Because of the greater depth, the bottom condensate walls 105 are beneath and spaced below the glazing strip bodies 86 to project into the hollow interior 73 of the rafter. From the inward edge of the bottom walls 105, a wall 107 extends upwardly to and is integrally joined to the underside of the glazing strip body 86 and forms therewith a horizontally directed shoulder 109 which interconnects this lower wall 107 and upstanding outwardly facing wall 83 of the glazing strip body 86. Thus, as readily seen in FIG. 7, the condensate channels 27 in the rafters 17 have their bottom walls spaced beneath the bottom sides 81 of the condensate channels 21 so that liquid will flow through the discharge openings 37 therein into the rafter condensate channels 27.

As best seen in FIG. 6, the horizontally extending purlins 16 are supported by the vertically extending rafters 17 and interconnected thereto at spaced locations along the length of the rafters at notches 57 which receive the curbs 54 at the ends 55 of the purlins. The interconnecting means 53 secures the purlins against shifting from or separation from the rafters. The illustrated notches 57 are formed in the upper portion of the outer condensate channel walls 58 by making downward saw cuts to form cuts 111 spaced from each other by a distance slightly greater than the width of the purlin. The portion of the outer condensate wall 58 between the cuts 111 is removed as by being either bent and snapped off or cut from the rafter to form a horizontally extending support 114. The respective notches 57 extend downwardly to a predetermined depth and are related to the vertical dimension of the curb 54 with the result that when the curb lower wall 113 is placed on support 114 the glazing strips 87 on the purlins and rafters are aligned in a common plane to support the glazing panels 12. The curbs 54 on the purlins project outwardly from the vertical extending wall ends 71, which are abutted against the outer side walls 50 of the rafter tubular bodies, so that leading end walls 115 of the curbs 54 either engage or almost engage the outwardly facing walls 83 of the glazing strip bodies 86 on the rafter 17. Thus, the opposed purlins 16 are limited in relative movement inwardly toward each other and are limited against turning relative to the rafter by the walls at cuts 111 of the notches 57. The outward movement of the purlins 16 relative to one another and twisting of the purlins relative to the rafters 17 is prevented by the interconnecting means 53 which includes the horizontally extending pins 65 and the pins 63 which project downwardly from the purlins into the condensate channels 27. Preferably, the pins 63 and 65 are cylindrical, roll pins. Two pins 63 are forced into cylindrical bores drilled into the bottom of the glazing strip bodies 86 beneath the glazing strips 87. The pins 63 project downwardly of the wall 114 at the notches 57 to a position spaced above the bottom wall 105a of the rafter condensate channel. Should the purlins 16 tend to separate from the rafters 17, the roll pins 63 will abut the walls 58 and resist any such separating movement.

The purlins 16 are held by the notches 57 against shifting longitudinally of the rafter 17 and additionally are further held and aligned more precisely with other purlins 16 by the pins 65. More specifically, the pins 65, as best seen in FIG. 6, have one end forced into openings 121 in the glazing strip bodies 56 of the rafters 17 with opposite ends projecting horizontally to be received into the space between the upstanding cap-securing walls 95 and 96 as best seen in FIGS. 5 and 7. Also, the purlins 16 are held against lifting by the rafter glazing cap 43 which extends over the curbs 54 on the purlins. The purlin glazing caps 40 extend between and terminate at the glazing caps 43 for adjacent rafters 17.

In accordance with the further embodiments of the invention illustrated in FIGS. 8-11, a double glazing skylight construction 135 is provided with the improved condensate removal system of the present invention. More specifically, purlins 140 are secured to rafters 141 to support double glazing panels including upper or exterior glazing panels 143 and lower or interior glazing panels 145 separated by a large air space 147 therebetween. As will be explained in greater detail, only the exterior glazing panels 143 receive large amounts of condensate or bypass moisture. As with the single glazed structure purlin 16 of FIGS. 4-7, the purlins 140 have condensate channels 151 formed in the top portions thereof and adjacent the exterior glazing panels 143 to collect condensate and to deliver the collected condensate to rafter condensate channels 153 formed in the upper portions of the rafters 141 adjacent the upper glazing panels 143. In this instance, only a single purlin condensate channel 151 is provided for collecting condensate along the downward sloping side of the glazing panels 143. An end 155 of the condensate channel is spaced from a wall 156 of the rafter, as best seen in FIG. 9, to allow moisture discharging from a bottom wall 157 of the chanel to drop through the space between its end 157 and rafter wall 156 and collect in the underlying rafter condensate channels 153.

The upper glazing panels 143 rest upon and are supported by resilient, neoprene glazing strips 161 on the respective purlins 140 and rafters 141, the glazing strips 161 being substantially identical to the glazing strips 87 hereinbefore described. On the exterior side of the upper glazing panels 143 is a purlin glazing cap 163 which is substantially identical to the purlin glazing cap 40 and hence will not be described in detail herein. Likewise, the rafter glazing caps 165 for exterior glazing panels 143 are substantially similar in construction and function to the rafter glazing cap 43 hereinbefore described and will not be described again. Also, glazing blocks 169 are disposed against the edges of the exterior glazing panels 143 and are supported in the manner of the glazing blocks 93. The glazing blocks 169 are carried in grooves 170 which also serve to collect exterior water by-passing the glazing cap 40. A central groove 170a to receive the screw fastener for the rafter glazing cap 165 also serves as a by-pass water collecting channel.

The purlin condensate channels 151 are disposed slightly beneath the interior sides of the upper glazing panels 143 and along the top of the purlins 140. In this instance, the purlin condensate channels 151 are formed as an extension of an upper transverse wall or flange 175 which extends generally horizontally and carries the glazing strips 161 and the glazing block 169. More specifically, a bottom wall 176 for the condensate channel is in a common plane with and integrally joined to the flange 175. This bottom wall 176 extends to an upwardly inclined outer condensate wall 177 which is spaced from an inner condensate channel wall 179 formed on the glazing strip body. If desired, a second condensate channel 151 may be formed on the other side of the purlin 140.

The rafter condensate channels 153 in the rafters 141 are disposed at a slightly lower level than the purlin condensate channels 151 and have a greater depth and width than the condensate channels 151. The rafter condensate channels are formed at the top portions of the rafters adjacent the interior side of the upper glazing panels; and are formed with an open top, an outer vertical wall 181, a bottom wall 183, and an inner wall 185 extending to the underside of the glazing strip body.

A top edge 188 for the outer condensate walls 181 is preferably located at a position beneath the transverse flange 175 on the purlin to assure that the purlin and rafter glazing strips 161 are aligned in a common plane for supporting the upper glazing panels 143 when ends of the purlin flanges 175 rest on the upper edge 188 of the rafter condensate channel walls, as best seen in FIG. 8. As will be explained in detail hereinafter, the rafter condensate walls 181 are not notched with the notches 57 disclosed above.

As the purlins 140 and rafters 141 have generally similarly shaped lower sections, these lower sections will be described simultaneously and common reference characters will be applied thereto. Therefore, a description of the lower portion of the purlin 140 will suffice for an understanding of the lower portion of the rafter. The purlin 141 has a central vertically extending web 191 which extends from the top flange 175 to a lower transversely extending flange 193 which carries a pair of glazing supports 195 each having a pair of glazing strips 197 for supporting the marginal edges of the lower glazing panels 145. Glazing blocks 199 abut the edges of the glazing panels 145 and are disposed in grooves 201 between the glazing strip bodies 195 and one of a pair of upstanding, longitudinally extending walls 203 spaced from and on opposite sides of the central web 191.

A pair of inner glazing caps 205 of Z-shaped configuration are secured to opposite sides of the central web 191 of the purlin to hold the lower glazing panels 145 in position against the glazing strips 197. More particularly, the inner glazing caps 205 have an upstanding securing flange 209 which is apertured to receive bolt and nut fasteners 211 to fasten the caps 205 tightly against the central web 191. The inner glazing caps are formed with an outward transversely extending plate 213 integral with the securing flange 209 which at its outer end is formed with a depending glazing strip body 215 carrying a lower glazing strip 217 abutting the upper side of the lower glazing panel 145 at a position opposite the purlin glazing strips 197. In this manner, the lower glazing panels 145 are secured to the purlins and rafters. As best seen in FIG. 8, it is preferred to provide a clean bottom appearance formed by having the bottom surfaces of the purlins and rafters intersect, abut, and be flush with each other.

The purlins 140 and rafters 141 are interconnected by a angle-shaped connectors 221 which have one leg 223 fastened by a nut and bolt connection 225 to the central web 191 of the rafter. A second leg 227 of the connector 221 is fastened in a similar manner by a nut and bolt fastener 229 to a web 191 of the purlin 140.

In the preferred manner of interconnection, the rafters 141 are uncut with the ends of the purlins cut as best seen in FIG. 9 to provide a top curb 230 and a lower web projection 231. The latter projects from the curb 230 into the space between the upper and lower flanges 175 and 193 on the rafter 141. A hole 237 is drilled into the projection to receive the shank of the bolt of the fastener 229. Preferably the projection 231 extends to a leading end 237 which may abut or be closely adjacent to the rafter central web 191. The projection has an upper side 239 which extends beneath the end 233 of the upper transverse flange 175 for the purlin to form the curb 230 to allow it to project over the rafter condensate channel 153 and to rest on the edge 188 of its outer condensate wall 181, as illustrated in FIGS. 8-11. Thus, the bottom wall 157 the purlin condensate channel 151 may be superposed over the rafter condensate channel and condensate may discharge through the opening 155 into the underlying channel 153.

From the foregoing it will be seen that the purlins and rafters may be formed with condensate channels along their upper portions adjacent the glazing panels and that the prior art wide lower condensate flanges and channels may be eliminated. With the present invention, the condensate channels may be completely hidden, as viewed from below, or at least made inconspicuous. Also, the interconnecting means between channels may also be hidden or obscured from direct view therely eliminating the cluttered appearance of prior art interconnections. The overall skylight construction, the purlins and rafters are formed of simple and economical extrusions which are cooperatively related in a novel manner to provide a strong safe structure at low cost and yet a skylight structure which will more adequately collect and remove moisture.

While a preferred embodiment has been shown and described, it will be understood that there is no intent to limit the invention by such disclosure but, rather, it is intended to cover all modifications and alternate constructions falling within the spirit and scope of the invention as defined in the appended claims.

Claims

What is claimed is:

1. In a skylight structure having a set of glazing panels and a framework supporting said panels, the improvement comprising purlins in said framework extending between a pair of adjacent rafters, said purlins having an elongated structural body, a pair of glazing supports on the upper portions of said purlin bodies extending longitudinally to support first edges of adjacent pairs of said glazing panels, means integral with said purlin bodies defining a pair of purlin condensate channels each extending longitudinally along said upper portion of said purlin body and adjacent to said glazing panels for receiving and carrying condensate, elongated rafters spaced from each other and supporting said purlins and having a structural body, a pair of glazing supports on said rafters on the upper portion of said body extending longitudinally of said rafters for supporting the other edges of the glazing panels, means integral with said rafter structure body defining a pair of condensate channels extending longitudinally along the upper side of said rafter structural body for receiving condensate from said glazing panels, said purlin condensate channels having portions disposed above and discharging moisture downwardly into underlying rafter condensate channels and interconnecting means securing said purlins and rafters to each other each of said purlin and rafter comprising a closed tubular body having a hollow interior, each of said tubular bodies comprising a pair of vertically extending side walls, a bottom wall joined to lower ends of said vertical side walls, and a top wall joined to the upper ends of said vertical side walls, said glazing supports being disposed along said top wall of said purlin and inwardly and intermediate of said condensate channels and projecting upwardly of the upper edges of said purlin vertical side walls to space said glazing panels therefrom, means disposed centrally of said purlins and between said glazing supports on said top wall to secure a cap means thereto, said rafter glazing supports being disposed along said top wall of said rafter and inwardly and intermediate said rafter condensate channels and projecting upwardly of the upper edges of said rafter vertical side walls to space said glazing panels therefrom, said glazing panels being spaced upwardly of said condensate channels in said purlins and said rafters and extending thereacross and means disposed centrally along said rafters and between said glazing supports on said top wall to secure a cap means thereto.

2. In a skylight structure having a set of glazing panels and a framework supporting said panels, the improvement comprising purlins in said framework extending between a pair of adjacent rafters and having an elongated substantially closed tubular structural body, spaced glazing supports on said purlins extending along an upper longitudinally extending side of said tubular body to support first edges of a pair of said glazing panels, means integral with said closed tubular body defining a pair of condensate channels each extending longitudinally along an upper porioon of said body and adjacent said glazing panels for receiving and carrying condensate therefrom, elongated rafters spaced from each other and supporting said purlins and having substantially closed structural bodies, glazing supports on said rafters extending longitudinally of said rafters along an upper longitudinally extending side of said closed body for supporting the other edges of said glazing panels, means integral with said closed tubular rafter body defining a pair of spaced condensate channels extending longitudinally along an upper longitudinally extending portion of said closed rafter body for receiving condensate from said glazing panels and from said condensate channels of said purlins joined to opposite sides of said rafters, cap means on the exterior side of said glazing panels for fastening to said purlins and rafters to hold said glazing panels on said glazing supports; and interconnecting means securing said purlins to said rafters to provide said framework each of said purlin and rafter comprising a closed tubular body having a hollow interior, each of said tubular bodies comprising a pair of vertically extending side walls, a bottom wall joined to lower ends of said vertical side walls, and a top wall joined to the upper ends of said vertical side walls, said glazing supports being disposed along said top wall of said purlin and inwardly and intermediate of said condensate channels and projecting upwardly of the upper edges of said purlin vertical side walls to space said glazing panels therefrom, means disposed centrally of said purlins and between said glazing supports on said top wall to secure a cap means thereto, said rafter glazing supports being disposed along said top wall of said rafter and inwardly and intermediate said rafter condensate channels and projecting upwardly of the upper edges of said rafter vertical side walls to space said glazing panels therefrom, said glazing panels being spaced upwardly of said condensate channels in said purlins and said rafters and extending thereacross and means disposed centrally along said rafters and between said glazing supports on said top wall to secure a cap means thereto.

3. A skylight structure in accordance with claim 2 in which said glazing supports comprise means defining a pair of longitudinally extending channels along said top wall and flexible resilient glazing strips therein for supporting the marginal edges of said glazing panels, said condensate channels being closely adjacent and parallel to said glazing strips.

4. A skylight structure in accordance with claim 2 in which the upper longitudinally extending edges of said side walls of said rafters are notched and in which said top walls of said purlins are formed with longitudinally extending projections inserted into said notches to be supported by said underlying rafters.

5. In a skylight structure having a set of glazing panels and a framework supporting said panels, the improvement comprising purlins in said framework extending between a pair of adjacent rafters and having an elongated substantially closed tubular structural body, spaced glazing supports on said purlins extending along an upper longitudinally extending side of said tubular body to support first edges of a pair of said glazing panels, means integral with said closed tubular body defining a condensate channel extending longitudinally along an upper portion of said body and adjacent said glazing panels for receiving and carrying condensate therefrom, elongated rafters spaced from each other and supporting said purlins and having substantially closed structural bodies, glazing supports on said rafters extending longitudinally of said rafters along an upper longitudinally extending side of said closed body for supporting the other edges of said glazing panels, means integral with said closed tubular rafter body defining a pair of spaced condensate channels extending longitudinally along an upper longitudinally extending portion of said closed rafter body for receiving condensate from said glazing panels and from said condensate channels of said purlins joined to opposite sides of said rafters, cap means on the exterior side of said glazing panels for fastening to said purlins and rafters to hold said glazing panels on said glazing supports; and interconnecting means securing said purlins to said rafters to provide said framework, said interconnecting means comprising locating and retaining pins extending between said purlins and rafters to hold against the separation of one from the other, and certain of said locating pins being secured in said purlins and project downwardly therefrom into said condensate channels in said rafters.

6. A structure in accordance with claim 5 in which other locating pins extend in a direction parallel to the longitudinal direction of said purlins and project between said purlins and rafters.