Note: Descriptions are shown in the official language in which they were submitted.
BACKGROUND OF T~IE INVENTION
(1) Field of the Invention
\
The present invention relates to wall construction, and
more particularly refers to studs which may be utilized to
form fire-retardant or ~ire-rated wall structures particularly
for-use in enclosing open shafts in multi-story buildings such
as offices and high-rise apartments, and to the wall structure
formed therewith.
(2) Description of the Prior Art
.
Walls enclosing shafts such as air return shafts, eleva-
tor shafts, and stairwell shafts commonly separate the shafts
from other rooms such as corridors, toilets, and utility rooms.
With increasing governmental concern for promoting safety for
occupants of public buildings, manufacturers of building pro-
ducts have sought to provide shaft walls meeting at least
minimal safety requirements, whi.le at the same time, providing
builders with materials that are both easy to install and low
in cost.
Two of the most important of these safe~y requirements
concern wind loading and fire ratings. Destructi~e wind
loading is of particular concern where the shaft is an air
return shaft or an elevator shaft, where pressures or vacuums
are developed which load the shaft wall up to 15 pounds per
square foot in excess of atmospheric pressureO
Cavity walls, and particularly those utilized for en-
closing elevator shafts, stairwells, and air return shafts,
are continually being subjected to increasingly stringent
fire code requirements. The trend is to require such walls
;9;
to meet or surpass certain fire ratings measu.red pursuant
to ASTM E-ll9 Fire Rating Test. Elevator shaft walls require,
for example at least a 2-hour rating. Where the wall system
is "unbalanced'l, increasingly, code enforcement organizations
are requiring that the rating be achieved from both sides of
the wall. To pass such tests, heat trans~er through the metal
studs used to construct such walls must be substantially re-
duced~ At the same time, however, the stud must still retain
a sufficient degree of structural strength, and in addition,
must meet economic requirements. Moreover, the enga~ement of
the stud with the wall panels which they support must be of
such nature that construction is achieved with a minimum of
required labor and materials. The structure must, never-
theless, withstand the requirements of accurate and complete
en~agement of the panels and studs, to ensure that the fire
rating will be achieved.
The above fire problems concerni.ng shafts can also be
said to.apply to long corridors in buildings, which in effect
are horizontal, rather than vertical, shafts. Thus, without
adequate fire ratings, a corridor wall easily transmits the
fire throughout the floor as the fire proceeds along the
corridor.
To solve these and other problems, early building shaft
walls were commonly built up and lined with various types of
block masonry, including both concrete and gypsum block.
~hile block masonry has proved suitable for many applications 9
it has been found to be undesirable in those situations where
the shaf~ rises to great heights. Further~ block masonry
structures cannot withstand high wind loading. Because of
their great weight, concrete block masonry materials require
supporting structures of great weight and strength. An
additional problem is that these heavy materials give rise
to problems in their installation. Those skilled in install-
ing the above-described shaft lining materials are forced to
handle them at dangerously high levels.
Walls of the type described and related structures have
been disclosed in the prior art, and particularly in U.S.
Patent Nos. 3,740,912, 3,702,044, 3,609,93~, 3,016,116,
3,094,197, 999,752, 3,495,417, 3r271,920, 3,839,839, and
many others. However, even though many of the structures
disclosed in these patents have proven to be highly satis-
factory, the search has continued to provide wall structures
of the type described of greater strength, and greater fire-
retardant properties.
In U.S. Patent No. 4,152,878 there is disc]osed a highly
satisfactoxy stud and fire-rated shaft wall structure. How-
ever, the stud is somewhat expensive to construct since it
uses a substantial amount of metal.
SUMMARY OF THE INVENTION
It is accordingly, an object of the invention to
provide a stud for the construction of a cavity shaft wall
for mul-ti story buildings, which walls meet safety standards
of wind loading.
It is a further object to provide a stud for the proauc-
tion of a cavity shaft wall, which wall can meet required
fire rating tests even when utilizing relatively thin wall-
board panels.
It is an additional object to provide a stud for the
production of a cavity shaft wall which is relatively
inexpensive, lightweight, and relatively easy to install.
It is a further object to provide a building structure
utilizing studs of the type described wherein both layers
of wallboard panels can be inserted from the outside or
corridor side, thereby obviating the need for workmen to
erect scaffolding and to work within an elevator shaft
around which the shaft wall is beiny installedO
Other objects and advantages will become apparent
upon reference to the drawings and detailed description.
According to the invention~ a fire-rated cavity shaft
wall structure is provided utilizing a plurality of metal
studs according to the invention and a plurality of gypsum
wallboard panels to form two spaced-apart rows with each of
the panels having two opposed vertical edges, a stud being
interposed between adjacent panels, and mounting the panels.
Each of th~ studs has a web portion formed of a single layer
of metal, a pair of oppositely directed continuous flanges
provided at one edge of the web, an oblique panel integrally
connected with the web, and a supporting panel spaced
apart from the oppositely directed flanges and in substan-
tially parallel relationship thereto~ Additionally, tabs
are struck out on both sides of the oblique panel to
provide oppositely direct~d discontinuous flanges sub-
stantially parallel to the oppositely directed contin-
uous flanges. The oppositely directed continuous flanges
and the oppositely directed discontinuous flanges CQ-
operate to define oppositely directed channels in which
the edges of adjacent gypsum board panels may be inserted
from the corridor side of the shaft wall. In assembling the
structuxe, one layer of wallboard is inserted in the
oppositely directed channels formed by the flanges, and
another layer of-wallboard panels is subsequen~ly affixed to
the wallboard-supporting panels by nails or screws. The
entire structure may be assembled by workmen positioned in
the corridor side of the shaft wall. Additionally, slots
may be provided in the web to improve the fire-rated proper-
ties~
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 is a side elevational view of a stud according
to the invention.
FI&~ 2 is a cross-s~ctional view taken at the line 22
of FIG. 1, looking in the direction of the arrows.
FIG. 3 is a cross-sectional view of a stud similar to
that of FIGS. 1 and 2, but wherein the orientation of the
oppositely directed flanges and the base panel are reversed.
PIG. 4 is a perspective view of a portion of a cavity
shaft wall embodying the stud of FIGS~ 1 and 2.
FIG. 5 is a fragmentary cross-sectional view taken at
the line 5--5 of FIG. 4, looking in the direction of the
arrows.
FIG. 6 is a perspective view of a portion of a wall
suitable for use in stairwells, and
FIG. 7 is a fragmentary cross-sectional view taken at
the line 7--7 of FIG. 6, looking in the direction of the
arrows.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIGS. 1 and 2, a stud 10 is shown formed
of a unitary int.egral sheet of metal such as steel or
aluminum. The stud comprises a continuous flange-forminc3
panel 11 comprising an outer panel member 12 terminating at
a first fold 13, and an inner panel member 14 connected to
the first fold 13, folded over onto the outer panel member
12, and extending to a second fold 15, thereby defining a
pair of oppositely directed flanges 16 and 17.
A web 18 is connected at the second fold 15 and e~tends
substantially perpendicularly with respect to the outer panel
member 12 to a third fold 19. An oblique panel 20 which is
acutely angled with respect to the plane of the web 18 extencls
from the third fold 19 and is connected by means of a portion
thereof or connecting panel 27 to a wallboard supporting
panel 21 which is disposed at an acute angle with respect to
7~
the oblique panel 20, perpendicular to the connecting panel
27, and substantially para~lel to the oppositely directed
flanges 16 and 17. The wallboard-supporting panel 21 may
be provided with a turned-over edge or flange 22. The
outer panel member 12 may also be provided with a turned-
over edge 23. Additionally/ in a preferred embodiment, a
groove 24 may be proviaed in the outer panel member 12 in
order to increase structural rigidity thereof. Further, a
conventional circular aperture 25 may be provided in the
oblique panel 20 to permit cables, wires and ducts to pass
through the stud. The web 18 is preferably provided with
elongate apertures 26, similar to those shown in U.S. Patent
4,152,878, issued May 8? 1979 to the present inventor. ~s
disclosed therein, the apertures have several functions.
First, they break up the heat conduction path transversely
through the web. Second, they facilitate heat dissipation
into the wallboards, and enhance the fire-rating properties
of a wall formed from a plurality of the studs and wallboards.
Although only a single row of apertures has been shown in
the structure of FIGS. 1 and 2, if desired two or more rows
may be utilized with the apertures preferably in staggexed
relationship. Additionally, if desired, apertures may be
placed in the outer panel member 12.
A pair of discontinuous flanges 28 and 29 are formed,
one on each side of the web 18, by striking tabs 31 and 32
from the web 18. The tabs alternate from one side to the
other of the web and are oriented substantially parallel
to the flange-forming panel 11. The discontinuous flanges
~3~ 75
28 and 29 comprised of the tabs 31 ana 32 ~ooperate with
the web 18 to define a pair of oppositely directea channels
33 and 34 in which the edges of adjacent wallboard liner
panels are inserted and retained.
In the studs shown in FIGS. 1 and 2 the folded-over
flange 17 is on the same side of the web 18 as the turned-
over flange 22 of the wallboard-supporting panel 21.
Alternatively~ the stud 30 shown in ~IG. 3 may be utilized
in which the folded-over flange 17' is on an opposite side
of the web 18 as the turned-over flange 22 of the wallboard-
supporting panel 21. In FIG. 3 the same numerals have been
utilized to show the structures which are the same as those
of FIG. 2, while prime numerals are utilized to show the
structures which are reversed. As can be seen, in addition
to the identical structures, the stud 30 comprises an outer
panel member 12' extending to a fold 13l, and an inner panel
member 14' extending to a second fold 15l and web 18.
Referring to FIGS. 4 and 5, a wall structure suitable
for use as a cavity shaft wall is shown utilizing stud 10 as
shown in FIGS. 1 and 2. The structure is in the form of a
cavity shaft wall structure 35 suitable for assembly from
the outer or corridor side with respect to the cavity around
which the wall is assembled, and comprises an upper 3-runner
36 having a web 37, a major or lar~e flange 38 on the shaft
side, and a minor or smaller flange 39 on the outer wall
side. The runner 36 may be affixed to a ceiling structure.
-10-
s
On the floor structure is mounted a lower J-runner 40ihaving
a web 41, a major flange 42 on the shat side, an~ a minor
flange 43 on the outer or corridor side. A plurality of
studs 10 are mounted inside the runners 36 and 40. As shown
in FIGS. 4 and 5, a layer or row of gypsum wallboard or
liner panels 44 is retained within the channels 33 and,34
of each stud and restrained by the web 18, the flanges 16
and 17 and the tabs 31 and 32. The liner panels are provided
with beveled panel corners 45 to facilitate insertion into
the channels 33 and 34, and additionally, to clear the
grooves 24 of the studs.
A first outer layer of wallboard panels 46 is affixed
to the wallboard-supporting panels 21 of each stud by means
of screws 47. A second layer of outer wallboard panels 48
is affixed to the first layer of panels 46 and the studs
10 by means of screws 49.
In erecting the wall, because of the structure of the
J-runners and studs, the entire wall may be assembled from
the outside or corridor sid of the shaft without the need
for placing workmen on scaffolding within the shaft to
assemble,any portion of the wall from the shaft side. In
assembling the wall the runners 36 and 40 are first affixed
to the ceiling and floor structures. A stud 10 is then
inserted between the flanges of the runners and maintained
in place by the flanges. The flanges may be screwed to
the stud if desired. A wallboard panel 44 is then set into
place with its bottom edge within the lower runner, and the
upper edge is swung into place into the upper runner. The
minor flange 39 is sufficiently narrow so that the upper
~ 3~ 7~i
edge of the wallboard panel 44 clears the ~lange and comes
to rest against the major flange 38. It can then be moved
laterally to become engaged within the channels 33 and 34.
A second stud is then mounted between the runners and moved
laterally until the opposite vertical edge of the panel 44
is engaged within one of the channels 33 or 34. Then another
stud is inserted. This process continues until the entire
inner wall is erected. The first outer wallboard panels 48
are then placed against the wallboard-supporting panel 21
of the studs and affixed in place by means of screws 47.
The second layer of outer wallboard panels 48 is then placed
against the flrst layer and affixed thereto and to the stud
by means of screws 49.
The results of fire tests indicate that the wall made
according to the invention and as described above equal
those obtained with the structure disclosed and claimed in
U.S. Patent No. 4,152,878. While performing excellently in
the fire tests, the present studs are considerably lighter
and less expensive than those disclosed in the afore-named
patent.
Referring to FIGS. 6 and 7, a modified embodiment of
the structure shown in FIGS. 4 and 5 is illustrated. This
structure is in most respects identical to that shown in
FIGS. 4 and 5 and identical numeral designations have been
utilized to refer to identical structure. However; the
structure of FIGS. 6 and 7 differs in that only a single
wallboard panel 46' is provided at the corridor side, and
a similar wallboard panel 4B', instead of being placed over
-12-
~3~3~7~
the panel 46', is affixed to the flanges 16 and 17 by means
of screws 49'. This structure provides a finished wall on
both sides and is useful for such applications as for stair
cases where there is no shaft on the inner side.
The studs of the present invention have many advan-
tages over those of the prior art. First~ they are as
strong as and provide comparable fire resistance as the
prior art studs such as those disclosed in U.S. Patent
No. 4,152,878. They also permit complete assembly of a
shaft wall from the corridor side. Additionally, because
of the geometic configuration, less material is required
~or their construction.
It is to be understood that the invention is not to be
limited to the exact details of operation or structure
shown and described in the specification and drawinys,
since obvious modification and equivalents will be readily
apparent to one skilled in the art.
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