Unitized skylight structure

A skylight system is formed of preglazed modules which are arranged side-by-side in a grid-like array which is supported on an underlying beam structure. The preglazed modules have slideably interfitting edges for joining to adjacent modules along all four sides of each module. The preferred modules are attached and are supported on corners thereof to the underlying beam structure. The interfitted edges allow slight relative shifting to accommodate expansion or contraction due to thermal conditions. Preferably, the modules may be supported and arrayed to define a flat surface or a predetermined curvature for the skylight. Broken glazing panels may be replaced in a given preglazed module. Gutters on adjacent modules are joined to provide a continuous moisture removal system.

The present invention relates to skylight or glass wall structures 
particularly useful as roofs of large buildings or as covering large 
atrium spaces and to the method of constructing the same. 
More specifically, the present invention is directed to a skylight system 
useable as a roof-like structure for an atrium or for the top of a 
building as distinguished from a curtain wall or facia of a building. Such 
skylight systems may be expected to carry relatively heavy loads and to 
have systems for removing condensate or water leakage. For instance, heavy 
snow, ice or other loads may be present on the roof or the atrium. Also, 
window washing equipment often must be supported on the roof or atrium 
skylight structure. 
Heretofore, skylight systems for this kind of use have been erected with 
individual rafters and purlins being built into gridwork on the job site 
and then later glazing panels are installed into the purlin and rafter 
gridwork. The present invention is directed to the elimination of the need 
for such preassembly of a rafter and purlin gridwork by using preglazed 
modules or units which are preassembled at another location such as a 
factory and shipped to the job site for erection directly onto a 
supporting structure. 
A typical support structure for an atrium in a large office building 
includes a series of beams extending parallel fashion in a given 
direction, for example, generally vertically or horizontally with few or 
no cross beams. Such beams are considerably larger than glazing support 
members such as purlins and rafters, and hence, it would be very costly to 
make an underlying beam support into a gridwork to support the glazing 
panels. Also, the aesthetics would be adversely effected. Usually, the 
glazing panels used for such atrium or the roofs have a maximum size of 
about 4 feet by 9 feet or, 5 feet by 10 feet, and hence, large beams would 
not be used in a manner to provide direct support for the glazing panels. 
When using preglazed modules they should be assembled in the skylight so 
as to allow for expansion or contraction due to thermal loading. Also, the 
skylight should not creak or make noise if it experiences wind or other 
dynamic loadings. Further, breakage of glass panels sometimes occurs and 
it is most desirable that the preglazed assemblies be designed to allow 
replacement of a broken glazing panel. Of course, such skylight systems 
should be sealed to be relatively weatherproof and have condensate removal 
systems for draining away condensate or water leaking past a seal. 
In many instances, the designer of the atrium, or roof desires to provide a 
curve or arcuate configuration for the structure. Since the sheets of 
glass are relatively large and flat, the skylight system using preglazed 
modules should be designed to allow an angular relationship between 
adjacent preglazed modules to accommodate the desired curvature for the 
entire roof or atrium. 
Accordingly, a general object of the present invention is to provide a new 
and improved skylight system and or preglazed modules which may be used as 
a roof or an atrium wall. 
The further object of the invention is to provide a method of making 
skylight system which will overcome the problems above-described.

DETAILED DESCRIPTION OF THE INVENTION 
As shown in the drawings for purposes of illustration, the present 
invention is directed to a preglazed module 10 (FIG. 1) having a glazing 
panel 12 preferably in the form of a large flat sheet of glass having a 
size about 5 feet by 10 feet. The preglazed modules 10 are supported on an 
underlying supporting framework 16 typically made of large support beams 
32. The preglazed modules are arranged in a grid-like array to form a 
skylight system 18 with the preglazed modules being interconnected with 
one another and with the underlying support framework 16. Herein, the 
underlying support framework 16 is formed with a plurality of parallel 
support beams 32, as shown in FIGS. 1-3, in the form of circular pipes 
extending horizontally and parallel to each other. Although the parallel 
beams 32 are in the form of circular tubes or pipes, other shapes may be 
used for the supporting framework 16. 
Usually the supporting beams 32 will be spaced apart a distance about equal 
to the width or height of the glazed panels. For instance, the beams 32 
illustrated herein are spaced at about 5 feet intervals with the glazing 
modules 10 having vertical height of 5 feet and a horizontal width of 
about 10 feet. In the framework 16 shown in FIGS. 1-3 there are no 
vertically extending beams. Of course, suitable cross or vertical beams 
may be provided, if desired, between the horizontal beams 32 at suitable 
locations to provide additional strength and rigidity. However, there is 
no need for, in fact, it is usually not desired to have the large beams 
extend in a grid-like pattern because of the expense and the aesthetics. 
It is, of course, to be realized that the beams 32 may be arranged 
parallel to each other in a vertical direction and disposed at 10 feet 
intervals rather than the being disposed horizontally and at 5 feet 
intervals as illustrated herein. Also, the dimensions may be changed from 
that given herein. 
As typical with skylight systems, a condensate or water removal system is 
provided to collect condensate condensing on the inside surface of the 
glazing panels 12 and to collect moisture leaking through an imperfect 
seal. The condensate removal system drains the water away without its 
dripping into the interior space. Herein, the unitized individual 
preglazed modules 10 are interconnected in a manner that their respective 
individual vertically extending, condensate channels or gutters 26 (FIG. 
4) on the vertical frame members 20 convey the collected water from one to 
another to convey the water in a downward direction to a discharge point 
(not shown). The preferred horizontal frame members 22 of the preglazed 
modules also have a condensate or gutter channel 28 which extends at least 
across the lower side of the module to carry condensate or moisture 
laterally and to discharge the moisture into an underlying gutter segment 
26. For instance, as shown in FIG. 4 by the dotted arrows "A", water may 
flow through the horizontal gutter 28 to discharge at an end 203 thereof 
to drop downwardly into the underlying vertically extending gutter 26 
which then carries the moisture downward. 
As will now be explaned in connection with FIG. 1, the preglazed module 10 
shown in full in FIG. 1 will be described as being fitted with and 
interconnected with adjacent preglazed modules 10a and 10b which are 
already mounted on the pair of supporting beams 32 shown in FIG. 1. As 
will be explained in greater detail hereinafter, each of the four sides 
20a, 20b, 22a and 22b of the preglazed module has an interlocking portion 
which is slideable into interlocking relationship with other adjacent 
modules so as to provide an interlocked gridwork of glazed modules having 
support frames connected at spaced intervals to the underlying beams. In 
the arrangement shown in FIG. 1 the lower horizontal frame member 22a of 
the module 10 will be slid into interlocking engagement with the upper 
horizontal support member 22b into already assembled preglazed assembly 
10b. Also, the preglazed module 10 will be slid to the left as viewed in 
FIG. 1 to interlock the left vertical support member 20a on module 10 with 
the right support vertical member 20b of the already assembled glazing 
module 10a. The remaining connection is to take the freehand corner 21 of 
the module 10 and to connect it to a corner support means which comprises 
a bracket means 34 which underlies the same as shown by the direction 
arrow as shown in FIG. 1. As will be explained in greater detail 
hereinafter, the preferred interconnection includes a weld between the 
module corner 21 and the underlying bracket means 34, although other 
fastening means could be used. Also, as will be explained in greater 
detail hereinafter, a "T-shaped" member 250 is then positioned betweeen 
the upper left hand corner 23 of the module and the upper right hand 
corner 21b of the preglazed module 10a. Thus, in this preferred embodiment 
of the invention each preglazed module 10 is secured at its upper two 
corners by means in addition to the sliding interfitted relationship it 
has along its vertical edges 20a, 20b and its horizontal edges 22a, 22b. 
The preferred construction resulting in the interfitted relationship 
between adjacent modules can be most readily understood from a review of 
FIG. 4 in which a lower projection 80 on a left hand vertical member 20a 
is slid into a slot 69 on the right hand vertical member 20b. The 
preferred sliding interlocking means includes a second means having a 
laterally projecting flange 94, on a right vertical member which, as shown 
by the arrows, is slid into the accommodating slot 96 on the left vertical 
member 20a. Similar interlocking slot and slideable interlocking flanges 
are presented on all four sides of each of the glazing modules as will be 
described in the detailed description hereinafter. As can be seen in FIGS. 
5 and 6, a gap is provided within the slots to allow individual expansion 
or contraction of the projecting flanges. Thus, the modules can 
accommodate expansion or contraction in different directions with the 
projecting flanges merely sliding in their receiving slots. 
After several of the modules have been assembled into an array and before 
the entire roof or skylight structure is assembled, it is possible to make 
the partially assembled array weather tight by inserting the weather 
strips 24a and 24b, as shown in FIGS. 5 and 6 between adjacent frame 
members of adjacent modules. The preformed and compressed weather strip 
seals 24a and 24b are preferably then overlayed with their respective 
caulk sealant 220 and 72. 
In the preferred embodiment of the invention, a glazing panel 12 may be 
removed if the same were broken in a preglazed module 10 by removal of the 
caulk 72, 220 and removably glazing strips 66a and 67b. Removal of the 
sealing strip 24b allows access to a fastener 171 (FIG. 6) which holds 
down an outer glazing strip 67a to an inner underlying glazing strip. In a 
like manner, as shown in FIG. 5, the removal of the caulking 220 and the 
seal 24a exposes a threaded fastener 102 which may be removed so that one 
may lift up the outer glazing strip 66a from the top of the glazing panel 
12. By removing the glazing strips 66a and 67a at a given corner of a 
module, the glazing panel 12 may be slid outwardly from the remaining two 
glazing strips and then lifted upwardly for removal. In a like manner, a 
new glazing panel 12 may be positioned and then slid inwardly into 
position with the glazing strips 67a and 67b being reapplied and 
refastened into position. Then the caulking and weather strips may be 
reapplied. This particular construction will also be described in greater 
detail hereinafter. 
In the illustrated embodiment of the invention, the skylight will be 
provided with a large curved surface with the curvature being in the 
vertical direction, as seen in FIG. 6, with the vertical support members 
20a and 20b being pitched at an angle of 2 1/4 degrees from a plane normal 
to a radius extending inwardly through the gap between adjacent modules 
and through the pipe beam 32. It is clear in FIG. 6, that the left and 
right hand glazing panels 12 are not coplanar and that their respective 
planes will intersect in the gap and at a particular angle. Herein that 
angle is called the segment angle. In this embodiment of the invention, 
each of the modules will be disposed at the same segment angle so that the 
modules will define a continually changing curvature of the same radius. 
Herein, the interconnection between adjacent modules is provided by 
bending the interlocking flanges 162 and 158 at a 4 1/2 degree angle from 
the plane of their associated glazing panels 12, as will be described in 
greater detail hereinafter. 
So that the invention will be more fully understood, the modular skylight 
array 18 will now be described in greater detail. 
In the illustrated embodiment, the structural framework 16 is provided 
interior of the skylight modules 10 holding the skylight modules 
thereabove. The structural framework 16 is formed of a plurality of beam 
members, herein tubes on pipes 32, running parallel to each other and 
along rows of interfitted horizontal frame members 22. The tubes 32 are a 
building component adjusted to carry an atrium like skylight or a roof 
like skylight. It is to be understood that the illustrated support 
framework 16 represents only one of many possible structural frameworks 
which may be used to support the modular array of the present invention: 
the tubes might be replaced by I beams or other shapes; the support tubes 
or beams might run along the lateral members or a lattice of support beams 
might be used where greater structural strength is required. 
As a means to provide for attachment of the modules 10 to the tubes 32, 
bracket means sometimes hereinafter referred to as bracket assemblies 34 
are secured at spaced intervals, herein, generally the length of the 
horizontal frame member 22, along the tubes. The bracket assemblies 34 
serve as corner supports in that each of the modules 10 is supported at 
its four corners by a bracket assembly 34. The bracket assemblies 34 
include an adapting bracket 36, (FIG. 6) having an arcuate underside 38 
matched to the cylindrical surface of the tube and a flat upper surface 
40, is laid over the tube. A channel bracket 42 having a flat bottom 44 
and a pair of upstanding flanges 46 perpendicular to the axis of the tube, 
is laid over the adapting bracket 46. The adapting bracket 46 and channel 
bracket are jointly attached to the tube by a pair of bolts 48. 
The bracket assembly 34 also includes a platform bracket 50, into which are 
slid cooperating portions of the module frames 14, is carried by the 
channel bracket 42. The platform bracket 50 has a base 52, a pair of 
depending flanges 54, which are attached by horizontal bolts 55 to the 
upstanding flanges 46 of the channel bracket 42, and a pair of sidewalls 
56 extending upward from the base. Each sidewall 56 has a lip 58, as best 
seen in FIG. 7, extending inwardly from its upper end to overly and hold 
down a frame member 20a or 20b. 
The frame 14 of the module 10 is preferably formed of the extruded aluminum 
members 20, 22. With references to the drawings, the vertical frame 
members 20 may be thought of as rafters of the skylight 18, and the lower 
members 22 may be thought of as purlins interconnecting the rafters. The 
terms are used interchangeably herein. Two types of vertical members 20a, 
20b are used, one type interfitting with the other, and herein, the two 
types will be referred to as left vertical members 20a and right vertical 
members 20b with reference to the orientation of FIG. 5. Similarly, two 
types of horizontal members are used, one type interfitting with the 
other, and herein they will be referred to as lower horizontal member 22a 
and upper horizontal member 22b with reference to the orientation of the 
frame FIG. 6. The frame 14 of each module 10 comprises a left and a right 
vertical member 20a, 20b and a lower and upper horizontal member 22a, 22b. 
Each vertical member 20 and each horizontal member 22 includes a lower 
body portion 60, 61 including gutter segments 26, 28 and an upper portion 
66, 67 which receives the glazing panel 12. As a means of inserting the 
glazing panel 12 in the frame 14, the upper glazing porions 66a, 67a of 
the left vertical member 20a and left horizontal member 22a are formed 
separate from the body portions 60a, 61a and attached to the body portions 
after insertion of the glazing panel 12. 
The body portion 60a of the left rafter 20a provides a segment 26 of the 
gutter structure by which water is conveyed from one module 10 to another 
to the edge of the skylight structure. The gutter segment 26 also provides 
the means of attaching the modules to the platform brackets 50. 
The gutter segment 26 includes a bottom plate 70 and a pair of upstanding 
sidewalls 72. The bottom plate 70 and sidewalls 72 are proportioned to 
slide into the platform brackets 50 with the bottom plate 70 resting on 
the base plate 52 and the gutter segment sidewalls 72 closely adjacent the 
platform sidewalls 56 and extending upward to the sidewall lips 58. Where 
the skylight 18 is inclined, the lower of a pair of rafter ends is 
generally welded 59 to hold the lower module from sliding down in a 
water-tight fashion to the platform bracket 50 as shown in FIG. 6. As seen 
in FIG. 6, the water will be flowing from right to left and across the gap 
between adjacent gutter ends on the respective rafters. The welded 
attachment at one end of the left vertical member 20a generally provides 
the only immobilized connection for each given module 10 to the structural 
framework 16, and by this single immobolized connection, the module 10 is 
positioned in the modular skylight structure. The other upper end of the 
module is attached by a T-shaped key to an adjacent module, as will be 
explained in greater detail. The lower of the pair of ends are unattached 
and free to slide within the platform bracket 50 whereby continuous 
downhill gutter channels are provided while shifting of adjacent modules 
is permitted to allow for thermal contraction and expansion. 
A flange 74a extends upward from the bottom plate 70 of the left rafter 26 
gutter structure toward its outer (right) side and carries an outwardly 
facing, U-shaped piece 71 which provides a U-shaped recess 73 into which 
is slid a protrusion 80 of the right rafter 20b. Another flange 74b 
extends upward from the bottom 20 of the left rafter 20a towards its inner 
side and carries a body wall 82. 
At each of the four corners of a preglazed module, the adjacent ends of the 
respective purlins and rafters are joined together by an angle 88 which is 
slid into a guideway or track formed on each rafter and purlin. As viewed 
in FIG. 5, the body wall 82 has a pair of angle pieces 84a, 84b on its 
outwardly facing (right) side, a lower angle piece 84a having its free 
section pointing upward and an upper angle piece 84b having its free 
section pointing downward whereby the angle members provide a track 86a 
for a rafter-purlin interconnecting angle member 88. Thus, the four 
corners of the rafters and purlins of each module are joined at a corner 
by an angle 88. 
At the upper end of the body wall, a horizontal central piece 90 provides 
an upwardly facing groove 92a for receiving a tongue 93 of a lower glazing 
gasket 95 that forms a seal along the edge of the glazing panel 12 carried 
thereontop. The central piece 90 also provides an end protrusion 94 to be 
slide into a U-shaped recess 96 of the right rafter 20b and an upper ridge 
98 which receives a connecting flange 100 of the glazing portion 66a of 
the left rafter. 
The purlin and rafter members 20a and 22a each have a detachable outer 
glazing strip which overlies an edge of the glazing panel 12 to lock the 
same to its associated purlin or rafter. As best seen in FIG. 5, an upper 
glazing strip 66a for the left rafter 20a is attached to the lower body 
portion 60a by bolts 102 holding the connecting flange 100 to the central 
piece 90. A glazing panel backing wall 104a extends upward from the inner 
side of the connecting flange 100. A pair of spaced-apart ridges 106 on 
the outer surface of the backing wall 104a cooperate with similar ridges 
on a backing wall 104b of the right rafter 20b to hold the resilient 
weather strip 24a therebetween. 
From the upper end of the backing wall 104a, a top piece 110 extends inward 
(to the left) to provide with the central piece 90 of the body portion 60a 
a channel 112a in which the glazing panel 12 is received. The top piece 
110 has a pair of downwardly depending ridges 114 providing a groove 116 
in which a segment of upper glazing gasket 118, that extends along the 
periphery of the glazing panel 12, is received. 
The top piece 110 also carries at its inner (left) edge an angle piece 120a 
having an upstanding section 122 and an outwardly extending section 124 
which, along with a facing angle piece 120b of the right rafter, provides 
the track 30 in which a window washing device may be conveyed across the 
skylight washing several modules in its sweep. 
The right rafter 20b is formed as a unitary structure with an edge of the 
glazing panel being slid laterally therein (FIG. 5). The body portion 60b 
includes a body wall 82b and a lower piece 128 and central piece 130 
extending outwardly (to the left) therefrom. The lower piece 128 has an 
upstanding flange 132 which forms one-half of rafter-purlin 
interconnection track 86b, and the horizontal protrusion 80 which slides 
into in the U-shaped recess 73 of the left rafter 20a. The central piece 
130 provides an upwardly facing groove 92b which receives a segment of the 
depending tongue 93 of the lower glazing panel gasket 95 and the outwardly 
facing U-shaped recess 96 in which the protrusion 94 of the left rafter 
20a is received. A short flange 138 depends from the central piece 
providing the other half of the rafter-purlin interconnection track 86b. 
The upper glazing portion 66b of the right rafter 20b includes a backing 
wall 104b extending upward from the outer edge of the central piece 120 
and a top piece 140 that forms with the central piece a channel 112b for 
receiving the glazing panel 12. A pair of ridges 114 depend from the top 
piece provide a groove 116 in which a segment of the upper glazing gasket 
118 is received. The top piece 140 also carries, at its outer edge, the 
angle piece 120b which forms the other half of the window washing track 
30. 
Referring now in greater detail to the right and left purlin 22a, 22b, 
shown in FIG. 6, the lower edges of the purlins are at the level of the 
upper edges of the platform bracket sidewalls 56 whereby water drains from 
the purlin gutter segments 28 to the elongated gutter channels formed by 
interconnected rafter gutter segments 26. Although the purlins 22 are 
illustrated in FIG. 6 generally horizontal, the interfitted purlins 22a, 
22b in the particular embodiment is for a structure in which the 
interfitted modules 10 are sloped upward (to the right), and in this 
embodiment, only the right purlin 22b has the gutter segment 28 to catch 
downwardly flowing water. 
The body portion 61a of the left purlin includes an inner body wall 152, an 
outwardly extending lower piece 154 and an outwardly extending central 
piece 156. The lower piece 154 has an outwardly extending protrusion 158 
for sliding into an interfit with a U-shaped recess 160 of the right 
purlin 226 and a pair of upwardly extending flanges 162, 164. The inner 
flange 162 provides one-half of a purlin-rafter interfitting track 86c, 
and the outer flange 164 provides one half of a key track 166. The central 
piece 156 provides an upwardly facing groove 92c at its inner (left) end 
for receiving a segment of the tongue 93 of the lower glazing gasket 95, 
an outwardly facing protrusion 162 for sliding interfit with a U-shaped 
upper recess 164 in the right purlin 22b and a pair of depending flanges 
167, 168 which complete the other halves of the purlin-rafter interfitting 
and key tracks 86c, 166. 
The upper removable glazing strip 67a of the left purlin 22a includes a 
connecting flange 169 by which it is attached by bolts 171 to the central 
body piece 156, an upstanding backing wall 104c and a top piece 170 
extending inwardly from the backing wall to provide with the central piece 
a channel 112c for receiving the glazing panel 12. The top pieces 170, 174 
of the purlins 22 are generally flush with the top pieces 110, 140 of the 
rafters 20, and the window washing tracks 30 carried by the rafters extend 
thereabove. The backing wall 104c has a pair of ridges 106 extending from 
its outer side which together with a pair of ridges 106 on a backing wall 
104d of the right purlin 22b hold the weather strip 24b. A pair of ridges 
114 depend from the top piece 170 for holding a segment of the upper 
glazing gasket 118. 
The lower body portion 61b of the intergal right purlin 22b includes a body 
wall 177, the inwardly extending purlin gutter segment 28, an outwardly 
extending lower piece 178 and an outwardly extending central piece 180. 
The lower and central pieces 178, 180 provide the outwardly (to the left) 
facing U-shaped recesses 160, 164 which receive the corresponding 
protrusion 158, 162 of the left purlin 22a. An upwardly extending flange 
184 on the lower piece 178 and a depending flange 186 of the central piece 
180 provide a rafter-purlin interconnection track 86d. The central piece 
180 also has an upwardly facing groove 92d for receiving a segment of the 
tongue 93 of the lower glazing gasket 95. 
The upper glazing portion 67b includes the backing wall 104d and the top 
piece 174 extending inward therefrom. The backing wall 104d has the pair 
of ridges 106 which help hold the weather strip 24b, and the top piece 174 
has a pair of depending ridges 114 for holding a segment of the upper 
glazing gasket 118. 
The preferred glazing panel 12 for use in the module 10 has safety and 
insulating features. Two sheets of glass 192a, 192b, bonded by a clear 
plastic material 194 comprise a lower panel 196. The resinous material 194 
prevents glass from spraying into the interior regions of the building if 
the glazing panel is broken. A single sheet of glass comprises an upper 
panel 198, which is spaced from the lower panel by a sealing spacer 199. 
The dead air space 201 between the panels 196, 198, of course, serves an 
insulating function. 
Moving clockwise around a typical module frame 14, a typical rafter-purlin 
sequence is a left or lower purlin 22a, a left rafter 20a, an upper or 
right purlin 22b and a right rafter 20b. With reference to FIG. 2, the 
lower purlin 22b with its gutter segment 28 is to the bottom of the 
incline in each module 10. The rafter segments 22 are joined end-to-end 
whereby the rafter segments 62 provide continuous drainage channels and 
the washing tracks segments 30 provide continuous track structures. The 
purlins 22, on the other hand, abut the rafters at their ends with the 
ends of the purlin gutter segments 28 extending over the sidewalls 72 of 
the rafter gutter segments 26. As seen in FIG. 5, the purlin gutter 
segment 28 is shortened at its end 203 to facilitate drainage of water 
into the rafter gutter segments 26. 
The frame 14 is constructed by initially joining body portions of the right 
rafters 20b and purlins 22b to the body portion of the left rafter 20a and 
purlin 22a. The rafters and purlins are interconnected at the four corners 
by means of four angles 88 having one section inserted into the 
interconnection track 86a, b of a rafter 20 and one section inserted into 
the interconnection track 86c, d of a purlin 26. After insertion, the 
angle pieces 88 are welded 204 to the respective frame members to securely 
connect the purlins 22 and rafters 20. 
The tongue 93 of the rectangular lower glazing gasket 95 is inserted into 
the upwardly facing grooves 92 of the interconnected frame members. 
Because the glazing portions 66a, 67a of the left rafter 20a and left 
purlin 22b have not been applied to the body portions 60a, 61a, the 
glazing panel 12 is inserted by lowering it into the upper side of the 
frame and sliding it into the glazing channels 112b, 112d of the right 
rafter 66b and right purlin 67b. Spacing blocks 206 of resilient material, 
e.g., neoprene are inserted into the corners of the glazing channels prior 
to insertion of the glazing panel to space the glazing panel from the 
backing walls 104. The spacing blocks 206 cushion the glazing panel and 
provide for different thermal expansion of the frames 14 and glazing panel 
12. The spacing blocks 206 have upper and lower protuberances 208 which 
extend the blocks between the central pieces and top pieces that define 
the glazing channels 112. 
After the glazing panel 12 has been inserted, the frame 14 is capped by 
bolting the removable glazing strips 66a, 67a of the left rafter 20a and 
left purlin 22a to the respective body portions 60a, 61a. The upper 
glazing gasket 118 is pressed into the groves 116 provided by the 
depending ridges 114 of the top pieces, and caulking 210 is applied along 
the upper edges of the glazing panel. 
To construct a skylight with modules of the present invention, the 
structural framework 16 is preassembled. Care is taken in the spacing of 
the parallel tubes 32 and in the spacing of the bracket assemblies 34 to 
provide a bracket assembly i.e. a corner support at each corner of each 
module 10. Each left rafter 20a is slid approximately halfway into a 
platform bracket 50 at each end whereby each pair of end-to-end left 
rafters is joined by a common platform bracket as seen in FIG. 6. Adjacent 
rafters 20 and purlins 22 are joined together by sliding them relative to 
each other so that their interfitting flanges mate with their 
corresponding U-shaped recesses. 
As seen in FIGS. 5 and 6, preferably the flanges 158, 162, 80 and 94 are 
considerably thinner than the respective recesses, and U-shaped strips 212 
of resilient material are applied to these flanges 158, 162, 80 and 94 
before insertion into the recesses whereby seals are formed between the 
protrusions and recesses. The strips 212 prevent squeaking and also assist 
in allowing expansion and contraction with thermal changes. 
The interfitting arrangement provides for the modules 10 to be joined 
together with good weather-proof sealing between adjacent modules, but 
also provides for some sliding movement between adjacent modules to 
accommodate thermal expansion and contraction. Adjacent modules are held 
together only by cooperation of the interfitted flanges and recesses and 
may pull together or spread apart slightly as the need may be. The weather 
strips 24, which provide the primary sealing between adjacent frame 
members are resilient enough to maintain their seal during such lateral 
shifting. Furthermore, the resilient U-shaped strips 212, carried by the 
flanges, provide, with the corresponding recesses, secondary sealing 
between adjacent modules 10, which secondary sealing is maintained 
throughout shifting. 
Because, generally only one end 21 of each module is permanently secured to 
a platform bracket 50, shifting is permitted in the lateral as well as the 
longitudional directions with respect to FIG. 2. Of course, it is not 
intended that the modules shift to any great extent relative to each 
other, and the modular construction assures that thermal effects are 
generally evenly distributed between all module interfittings rather than 
concentrated at certain locations as is typically the case in skylights of 
a unitary frame type construction. Accommodation of thermal effects 
becomes increasingly important as the size of the skylight structure 
increases. As a further consequence of the sliding interfit between 
adjacent modules, some tolerance is provided in assemblying the array of 
modules, slight misalignment of mounting brackets being corrected by the 
depth to which the protrusions are inserted into the corresponding 
recesses. 
At each corner 23, the T-shaped key 250 is slid into place to interlock 
three adjacent modules meeting at the corner. As best seen in FIG. 5, the 
key includes a straight leg or bar 251 which extends across the gap 
between modules in FIG. 5 and from a left end 253 to a right end 254. A 
cross bar 256 (FIGS. 5 and 6) on the key projects horizontally and at 
right angles to the bar 251. The cross bar 256 is short, as seen in FIG. 
6, and has a width to project laterally, in FIG. 5, across the gap to abut 
the angles 88 on the frame members 20a and 20b. This short cross bar is 
merely inserted into the gap shown in FIG. 5 to abut the corner angles 88 
on adjacent modules. The long bar 251 is preferably fastened such as by 
pins 260 (FIG. 6) extending through aligned holes in the bar and depending 
flanges 167 and 168 for the upper pin and aligned holes in the upwardly 
projecting flanges 162, and 164, which define the key tract 166. As best 
seen in FIG. 6, the lower and upper horizontal edges of the long bar have 
gasket strips 264 and 266 thereon to space the key from metal to metal 
contact with the respective flanges 167, 168 and 164 and 166. 
As seen in FIG. 6, the base plate 52 of the illustrated platform bracket 50 
is not flat from end-to-end, but rises slightly toward the center to 
accommodate the segment angle and the arcuate curvature of the skylight. 
This arrangement provides for a slight angle between one row of skylight 
modules and another. The angle of about 2 1/4.degree. in either direction, 
is accommodated by the design of the modules 10 without any modification 
because the resilient weather strips 24 and resilient U-shaped sealing 
strips 212 provide the necessary sealing even if the modules are not 
aligned in exactly the same plane. 
The skylight is extended to and is enclosed by an encircling frame of 
members which are to receive the lower, upper, and left and right hand 
edges of the skylight modules to join them to the surrounding structure. 
For instance, as will be explained in connection with FIG. 7, a lower 
frame member 300 extends horizontally along the bottom of the skylight and 
is attached to the usual bracket means 34 secured to the beam 32 and an 
exterior extruded aluminum flashing sheet 302 and interior extruded 
aluminum flashing sheet 304 extending from an upper edge 306 of a vertical 
building wall 308. More specifically, the lower edges of the flashing 
sheets 302 and 304 may be brought together along a vertical face 310 of 
the building wall and suitably joined thereto. Herein, a foam tape 312 of 
1 inch thickness is disposed between and adhered to the longitudinally 
extending edges of these sheets 302 and 304. The foam tape has 0.500 inch 
wide gaps below the vertical gutters 26 to allow water to flow down from 
between the sheets 302 and 304 and from the skylight across the vertical 
face of the building wall 308. The interior flashing sheet 304 extends 
inwardly and upwardly to be joined at its upper edge to the bracket means 
34 at the beam 32. The upper end of the exterior flashing sheet 302 is 
formed with a right angle flange 316 which is held by a horizontally 
extending adapter. A suitable sealing strip 320 and caulking 322 seal the 
upper end of the flashing strip to the frame member 300. 
The frame member 300 is made in the shape of a horizontal member 22a to 
match the horizontal members 22b on the lower ends of the adjacent modules 
10 (FIG. 6). The frame member 300 has upwardly projecting flanges 158a and 
162a in interfitted and slideable relationship with receiving slots 160a 
and 164a on the lower edge of the horizontal member 22b of the lowermost 
module 10 of the skylight. A sealing strip 324 is disposed between the 
lower edge of the module and the upper side of the frame member 300 to 
provide a horizontally extending seal. 
It is to be understood that the other three sides of the skylight may be 
likewise equipped with an edge frame member similar to frame member 300 
for with the other vertical side edges and the top edge of the skylight. 
Suitable flashing may be used to seal these three other sides of the 
skylight to the building structure. Thus, it is to be understood that 
these other frame members have the shapes, respectively, of the other 
horizontal and vertical members 22b, 20a and 20b to interfit with their 
associated side frame members on these other three sides of the skylight. 
Several advantages of the skylight assembly of the invention should now be 
more apparent. The modular structure taught herein is easily assembled and 
can be constructed to generally any size. The modules can be added to the 
array from any side unlike some previous skylight systems in which a 
predetermined order of construction must be followed. 
The individual modules have thin, lightweight frames which tend to maximize 
the amount of light-transmitting area and minimize the load on the lattice 
structure. Each frame is generally firmly attached at one upper corner to 
the support lattice positioning the module within the modular skylight 
array and it is keyed to another module at its other upper corner but is 
permitted by its sliding interfit with adjacent modules to shift slightly 
relative to the adjacent modules to accommodate thermal effects. The 
resiliency of the sealing strips maintains the weather-proof barrier 
despite the limited movement of the modules relative to each other. 
Furthermore, the sliding interfittings of adjacent modules provides some 
leeway in fitting adjacent modules and permits the modules to be installed 
in planes at a very small angle relative to each other. The gutters of the 
rafters and purlins and the interconnection of end-to-end rafters provide 
pathways to the edge of the skylight for all moisture which accumulates in 
the inside of the skylight. 
The skylight may be constructed from preglazed panels, a procedure which 
substantially reduces the time needed to construct the skylight. However, 
if a glazing panel should break, the glazing panel can be removed with 
relative ease by removing the removable glazing portions of the left 
rafter and the left purlin. The washing tracks provided by the rafters 
facilitate washing of the installed skylight structure. 
While the invention has been described in terms of a preferred embodiment, 
modifications obvious to one with ordinary skill in the art may be made 
without departing from the scope of the invention. 
Various features of the invention are set forth in the following claims.