U.S. patent application number 12/662822 was filed with the patent office on 2010-11-18 for open web stud with low thermal conductivity and screw receiving grooves.
Invention is credited to Ernest R. Bodnar.
Application Number | 20100287872 12/662822 |
Document ID | / |
Family ID | 43067357 |
Filed Date | 2010-11-18 |
United States Patent
Application |
20100287872 |
Kind Code |
A1 |
Bodnar; Ernest R. |
November 18, 2010 |
Open web stud with low thermal conductivity and screw receiving
grooves
Abstract
An open web low thermal conductivity steel stud, having a web
defining a longitudinal axis and a web plane, side edges along each
side of the web, main web openings formed through the web defining
two lengthwise sides parallel to the web axis, ribs extending
diagonally across the web between the main web openings, right
angle flanges formed around the main web opening and along the
ribs, bent away from the web, and having flange extensions formed
along the right angle flanges formed along the two lengthwise sides
of the main web opening, bent at further right angles into planes
parallel to but spaced from the web plane to define three sided
parallel spaced apart reinforcing channels extending lengthwise
along the web, rib openings at each end of each rib defining narrow
throat portions of the web for reduced heat transmission, at least
one stud leg formed along at least one web side edge, at right
angles to the web, and, two parallel screw receiving grooves formed
in the at least one stud leg, the grooves being spaced apart
equally on opposite sides of the centre of the stud leg.
Inventors: |
Bodnar; Ernest R.;
(Burlington, CA) |
Correspondence
Address: |
GEORGE A. ROLSTON
45 SHEPPARD AVE EAST, SUITE 900
TORONTO
ON
M2N5W9
CA
|
Family ID: |
43067357 |
Appl. No.: |
12/662822 |
Filed: |
May 5, 2010 |
Current U.S.
Class: |
52/582.1 ;
52/846 |
Current CPC
Class: |
E04C 3/09 20130101; E04B
2/789 20130101; E04C 2003/0434 20130101; E04C 2003/0473 20130101;
E04C 2003/0421 20130101; E04B 2/7412 20130101 |
Class at
Publication: |
52/582.1 ;
52/846 |
International
Class: |
E04C 3/32 20060101
E04C003/32; E04B 2/58 20060101 E04B002/58 |
Foreign Application Data
Date |
Code |
Application Number |
May 13, 2009 |
CA |
2668945 |
Claims
1. An open web low thermal conductivity steel stud, having a web
defining a longitudinal axis and a web plane, side edges along each
side of said web, main web openings formed through said web, said
openings defining two lengthwise sides parallel to said web axis,
ribs extending diagonally across said web between said main web
openings, right angle flanges formed around said main web opening
and along said ribs, bent away from said web, and comprising;
flange extensions formed along said right angle flanges formed
along said two lengthwise sides of said main web opening, bent at
further right angles into planes parallel to but spaced from said
web plane to define three sided parallel spaced apart reinforcing
channels extending lengthwise along said web; rib openings at each
end of each rib defining narrow throat portions of said web for
reduced heat transmission; at least one stud leg formed along at
least one said web side edge, at right angles to said web; two
parallel screw receiving grooves formed in said at least one stud
leg, said grooves being spaced apart equally on opposite sides of
the centre of said stud leg, and, planar regions on either side of
each said groove for receiving wall panel material thereon.
2. An open web low thermal conductivity steel stud as claimed in
claim 1, wherein said steel has a gauge of between about 0.88 mm
and 1.15 mm, and wherein the thermal transmission values as
compared with a standard C-section stud are reduced by between 80%
and 94%
3. An open web low thermal conductivity steel stud as claimed in
claim 1 wherein said stud includes an edge lip formed on said stud
leg, said edge lip being formed at an included angle of about 90
degrees.
4. An open web low thermal conductivity steel stud as claimed in
claim 3 wherein said edge lip is formed with a groove indented
therein.
5. An open web low thermal conductivity steel stud as claimed in
claim 1 wherein said rib openings are circular, and including
annular flanges formed from said web around said rib openings.
6. An open web low thermal conductivity steel stud as claimed in
claim 1 and including depressions formed in said web around said
rib openings, said depressions being of generally irregular
triangular shape.
7. An open web low thermal conductivity steel stud as claimed in
claim 1 and including depressions formed in said web adjacent to
said rib openings, said depressions being of generally linear
shape.
8. An open web low thermal conductivity steel stud as claimed in
claim 2 wherein said grooves have sides formed whereby to define an
included angle of between 75 and 90 degrees.
9. An open web low thermal conductivity steel stud as claimed in
claim 8 wherein said grooves are spaced apart from one another by a
distance of from between 70 mm and 105 mm.
10. An open web low thermal conductivity steel stud as claimed in
claim 9 and including a scribe line formed along said at least one
leg equidistant between said two grooves and defining the median
line of said leg.
11. An open web low thermal conductivity steel stud as claimed in
claim 1 wherein, in a given length of stud, the metal removed from
said stud by said main web openings and said root openings, leaves
a mass of metal in the locations of said restricted throat portions
is between about 16% and 21% of the total mass of metal in said
given length of stud.
12. An open web low thermal conductivity steel stud as claimed in
claim 1 including an embedment edge formed along said web, said
embedment edge defining a root portion, and a mid portion, with
concrete flow opening in said mid portion, and metal portions
punched from said openings being bent outwardly normal to said mid
portion, and a continuous lip formed on said mid portion, said lip
being bent at right angles to said mid portion.
13. An open web low thermal conductivity steel stud, having a web
defining a longitudinal axis and a web plane, side edges along each
side of said web, main web openings formed through said web, said
openings defining two lengthwise sides parallel to said web axis,
ribs extending diagonally across said web between said main web
openings, right angle flanges formed around said main web opening
and along said ribs, bent away from said web, and comprising;
flange extensions formed along said right angle flanges formed
along said two lengthwise sides of said main web opening, bent at
further right angles into planes parallel to but spaced from said
web plane to define three sided parallel spaced apart reinforcing
channels extending lengthwise along said web; rib openings at each
end of each rib defining narrow throat portions of said web for
reduced heat transmission; at least one stud leg formed along at
least one said web side edge, at right angles to said web; said
ribs and said throat portions, at a predetermined temperature
gradient across said stud, transmitting heat at between 5% and 20%
of the heat transmitted across a plain C-section stud.
14. An open web low thermal conductivity steel stud as claimed in
claim 13, wherein said steel stud is formed of steel of between
about 0.88 mm and 1.15 mm.
Description
FIELD OF THE INVENTION
[0001] The invention relates to steel studs for supporting drywall
panels, and in particular to an open web stud having low thermal
conductivity, and formed with grooves in predetermined spacings,
the grooves having a specific shape, for receiving dry wall
screws.
BACKGROUND OF THE INVENTION
[0002] Steel studs in construction, especially for erecting dry
wall, are replacing wooden studs for many reasons. Wood is becoming
scarce. Wood will warp, or may rot, or become infested.
[0003] Wood is inflammable. Also in many cases it has become less
suitable simply because it is heavy, and is bulky for
transportation. Wood has however two major advantages over steel
studs, namely that wood has low thermal conductivity, and that wood
will receive and retain dry wall fastenings such as screws.
[0004] Clearly it is desirable to use steel studs to overcome the
various disadvantages of wood, provided the two major problems with
steel as compared with wood can be solved. In addition, since steel
studs when installed are not subject to outdoor environment
conditions, they can be made from recycled steel with no loss of
performance, thus providing a good outlet for steel recovered from
other products. In the past there have been numerous proposals for
steel studs of various designs. In many cases steel studs were roll
formed as simple C-sections. These simple sections had a web, and
two "legs" or side walls, forming a simple rectangular channel in
section. Dry wall panels were secured to the two legs with dry wall
screws.
[0005] These simple C-sections are widely used throughout
commercial and high rise construction. They are unsatisfactory for
various reasons, most of which are well known.
[0006] Simple C-section studs are either of a heavier gauge steel
than is desirable or economical, or are of so light a gauge that it
renders them too flexible. Where such studs are too thin and
flexible, it becomes difficult to install screws to fasten the
panels.
[0007] Heavier gauge will permit ease of insertion of screws, but
it will transmit noise, and has high thermal conductivity. It also
uses more steel than is desirable. This may result in excessive
floor loadings in multi story buildings. The heavier the gauge, the
greater will be the cost of the raw material.
[0008] Lighter gauge steel may be considered to be more desirable,
but it can be difficult to install. The vertical and horizontal
members of a wall framed with such light gauge steel C sections may
be too weak and flexible, and the wall may vibrate. Fastening the
vertical stud members to the horizontal channels to make a frame is
also rendered difficult, since the fastenings, usually special self
tapping screws for use in sheet metal, are difficult to secure
firmly in the excessively thin steel material of the members. In
general the typical dry wall screws used in the trade for securing
dry wall to wooden studs, are not suitable for use with sheet metal
studs, especially, sheet metal studs of lighter gauge steel.
[0009] Self tapping screws for sheet metal are designed with a
chisel drill point and a threaded shank. These screws will hold
more securely in sheet metal. However when using lighter gauge
steel, the steel may be so thin that only one or two threads of the
screw shank with grip the metal. Another factor is that the light
gauge steel material of such simple C sections is often too
flexible to permit rapid insertion of screws. This slows down the
men installing the dry wall panels and ends up increasing the
overall cost of the work.
[0010] Plain C-sections are not suitable for erecting exterior
walls, or walls where the thermal gradient across the wall may be
significant, or where sound transmission is a problem. Such simple
sections have high thermal conductivity and can result in
condensation, known as "ghosting", along lines on the inside walls,
where the dry wall panels lie against the sides of the C section
studs.
[0011] Studs can be made with spaced apart openings, so as to
reduce thermal conductivity. Such studs may be classified as "open
web" studs. Studs can also be made with various flanges and ridges
to make them more rigid. However in the past such studs have been
more costly than plain C-section studs and have not found wide
acceptance. It is apparent that forming studs with complex
openings, ribs, and ridges will be more costly than rolling simple
C-sections. Thus if the more complex open web studs are to be
competitive with simple C-section studs, it must be on the basis
that while the open web studs may cost slightly more to make, they
are easier and quicker to install, and can be made of significantly
thinner gauge, thus using less material, than simple C-section
studs. Open web studs are also beneficial for reducing sound
transmission through the wall, and reduce the weight of the
building on its footings. For exterior walls, open web studs will
be far more attractive the simple C section studs since with
exterior walls thermal conductivity is a problem. The lower thermal
conductivity of open web studs will mitigate the problem of
"ghosting" condensation lines along the inner wall surfaces, which
was a problem with plain C section studs. For this reason every
effort must be made to reduce thermal conductivity to an absolute
minimum, while retaining the other advantages over C-section
studs.
[0012] Open web studs having low thermal conductivity are also
highly desirable for making exterior walls using exterior wall
panels which are a composite of thin shell concrete and steel
reinforcing studs. Such composite exterior panels have numerous
advantages over solid concrete exterior panels. One of the
significant advantages is that such composite panels incorporate
both the exterior concrete surface, in a relatively thin slab of
concrete, and in addition, incorporate steel studs on the inside of
the slab for reinforcing. The thinner concrete slab, saves the cost
of concrete, and also reduces the weight on the footings of the
building. The steel reinforcing studs extend from the interior
surface of the thin concrete slab and provide the interior studs
within the building to which dry wall can be attached.
[0013] Again, the ability to make such reinforcing studs of light
gauge steel has several advantages. The cost of material is
reduced. The weight of the composite panel is reduced. The thermal
conductivity of each stud is also reduced. This last advantage
results from the fact that lighter gauge steel, being of reduced
mass, will transmit only a reduced number of thermal units, at any
given temperature gradient, as compared with a stud of heavier
gauge.
[0014] Another factor arises from the use of lighter gauge steel in
open web studs. Such studs are widely used for supporting dry wall
panels. Panels are usually attached to the legs of studs with
screws. Where two panels abut edge to edge, then their edges must
lie side by side over one leg of a single stud. The leg width may
be less than five cms. This leaves only a relatively narrow support
for each panel edge. Screws must be secured, through each panel
edge, into the same stud leg, to hold the edges of the two abutting
panels onto the same leg.
[0015] Where light gauge steel is used to make the studs, then
there is a tendency for the legs to bend or twist, when screws are
being inserted. This tendency becomes more pronounced in the case
of open web studs, where the gauge may be even less than the gauge
of conventional C-section studs. This tendency can be reduced by
incorporating various ribs, webs and flanges in the studs, giving
them increased stiffness, in spite of their reduced gauge.
[0016] The invention further provides for this situation by the use
of two wide screw receiving grooves in each stud leg. The grooves
are formed parallel, at a predetermined spacing so as to optimise
the insertion of screw fastenings. The grooves have a width greater
than the width of the screw points, so as to assist in screw
penetration, and to permit the screws to drill into the sheet
metal, even where there is some twisting of the steel due to
pressure of the screw point, on the metal.
[0017] Between and alongside the two grooves the stud legs are flat
and planar, so as to support the panel edges, firmly. The grooves
also assist in forming tubular recess in the legs, when the screws
are inserted. These tubular recesses provide a greater security of
engagement for the threads of the screws.
BRIEF SUMMARY OF THE INVENTION
[0018] With a view to achieving a solution to these complex and
conflicting problems the invention comprises an open web low
thermal conductivity steel stud, having a web defining a
longitudinal axis and a web plane, side edges along each side of
said web, main web openings formed through said web, said openings
defining two lengthwise sides parallel to said web axis, ribs
extending diagonally across said web between said main web
openings, right angle flanges formed around said main web opening
and along said ribs, bent away from said web, and having, flange
extensions formed along said right angle flanges formed along said
two lengthwise sides of said main web opening, bent at further
right angles into planes parallel to but spaced from said web plane
to define three sided parallel spaced apart reinforcing channels
extending lengthwise along said web; rib openings at each end of
each rib defining narrow throat portions of said web for reduced
heat transmission; at least one stud leg formed along at least one
said web side edge, at right angles to said web, and, two parallel
screw receiving grooves formed in said at least one stud leg, said
grooves being spaced apart equally on opposite sides of the centre
of said stud leg.
The Invention Further Comprises
[0019] An open web low thermal conductivity steel stud wherein said
steel has a gauge of between about 0.88 mm and 1.15 mm, and wherein
the thermal transmission values as compared with a standard
C-section stud are reduced by between 80% and 94%, compared with a
conventional C-section stud. The invention further comprises an
open web low thermal conductivity steel stud wherein said stud
includes an edge lip formed on said stud leg, said edge lip being
formed at an included angle less than 90 degrees.
[0020] The invention further comprises an open web low thermal
conductivity steel stud wherein said edge lip is formed with a
groove indented therein.
[0021] The invention further comprises an open web low thermal
conductivity steel stud said rib openings are circular, and
including annular flanges formed from said web around said rib
openings.
[0022] The invention further comprises an open web low thermal
conductivity steel stud including depressions formed in said web
adjacent to or around said rib openings.
[0023] The invention further comprises an open web low thermal
conductivity steel stud wherein the mass of metal in the locations
of said restricted throat portions is reduced by between about 80%
and 94% compared with the mass of metal in an equivalent plain C
section stud.
[0024] The invention further comprises an open web low thermal
conductivity steel stud Including an embedment edge formed along
said web, said embedment edge defining a root portion, and a mid
portion, with concrete flow opening in said mid portion, and Metal
portions punched from said openings being bent outwardly normal to
said mid portion, and a continuous lip formed on said mid portion,
said lip being bent at right angles to said mid portion.
[0025] The various features of novelty which characterize the
invention are pointed out with more particularity in the claims
annexed to and forming a part of this disclosure.
[0026] For a better understanding of the invention, its operating
advantages and specific objects attained by its use, reference
should be made to the accompanying drawings and descriptive matter
in which there are illustrated and described preferred embodiments
of the invention.
IN THE DRAWINGS
[0027] FIG. 1 is a perspective view of a dry wall stud illustrating
the invention;
[0028] FIG. 2 is a section along 2-2 of FIG. 1;
[0029] FIG. 3 is a section similar to FIG. 2 but showing portions
of two dry wall panels, and screw fastenings, attached to the
stud;
[0030] FIG. 4 is a side elevation of a portion of the stud, showing
the various areas of reduced thermal transmission;
[0031] FIGS. 5, 6, 7, 8, and 9 are sections along 5-5, 6-6, 7-7,
8-8 and 9-9 of FIG. 4;
[0032] FIG. 10 is a schematic section of a portion of a stud
showing dry wall self tapping screws at two stages of
insertion;
[0033] FIG. 11 is a perspective of a low thermal conductivity stud
for reinforcing a composite concrete wall panel;
[0034] FIG. 12 is a perspective of the stud of FIG. 11 from the
opposite side;
[0035] FIG. 13 is a section along 13-13 of FIG. 11;
[0036] FIG. 14 is a side elevation of a further embodiment;
[0037] FIG. 15 is a side elevation of a further embodiment;
[0038] FIG. 16 is a perspective of a further embodiment;
[0039] FIG. 17 is a side elevation of FIG. 16;
[0040] FIG. 18 is a section along line 18-18 of FIG. 16;
[0041] FIG. 19 is a schematic view of a patin stud showing the heat
transmission paths; and,
[0042] FIG. 20 is a schematic view corresponding to FIG. 19 showing
the heat transmission paths of a stud according to the
invention.
DESCRIPTION OF A SPECIFIC EMBODIMENT
[0043] As explained above the invention is illustrated in the form
of a steel stud of light weight and having low thermal
conductivity. The stud has specific features adapted to facilitate
the attachment of dry wall panels, in a manner explained below, and
further features providing it with low thermal conductivity and low
sound transmission, as will be described below.
[0044] FIGS. 1 and 2 show a stud (10), which may generally be
classified as an "open web stud" for the purpouse of illustrating
the invention.
[0045] The stud (10) has a web (12). The web (12) defines an outer
mounting face (14) and an inner face (16). The web (12) is formed
with two parallel longitudinal web grooves (18).
[0046] Between the grooves (18) there are main web openings (20) of
generally trapezoidal shape. The openings (20) define long and
short longitudinal sides parallel to one another, and diagonal
sides joining the ends of the long and short sides.
[0047] Between the main web openings (20) ribs (22) extend
diagonally across the stud. Longitudinal flanges (24) extend along
the parallel sides of each opening (20).
[0048] Diagonal flanges (26) extend along each side of each rib
(22). Flanges (24) and (26) are bent at right angles to the plane
of web (12), to reinforce the stud.
[0049] Longitudinal flanges (24) are extended, by simply leaving
more metal from the web, in the flanges.
[0050] These longitudinal flanges (24) are bent at a further right
angle (28) so that they define an L-shape in section with the edge
portions lying in planes parallel to but spaced from the web
itself.
[0051] In this way these flanges (24), together with the adjacent
portions of the web (12), form three sided rectangular shaped
reinforcing channels (30) having centre portions and two opposed
walls, extending along the parallel linear longer and shorter sides
of each main web opening (20) for still greater strength.
[0052] Along each side of each rib (22) the flanges (26) form a
generally triangular peak (32), for increased strength. The rib
(22) varies in width along its length being narrowest at about its
median point.
[0053] At each end of each rib (22) there is a circular rib opening
(34) surrounded by an annular flange (36). The circular rib
openings (34) define two separate narrow throat portions (38) and
(40), one on each side of each circular rib opening ( )
[0054] The throat portions (38) and (40) at each end of each rib,
and the narrow median region of each rib all constitute thermal
restrictions or heat transmission barriers. Thus any heat being
transmitted across the stud, can pass only through these thermal
barriers.
[0055] Referring to FIGS. 5, 6, 7, 8, and 9, it will be seen that
the throat portions (identified and shown in elevation in FIG. 4),
are shown in section. Any heat being transmitted through the stud
will have to pass through these throat portions.
[0056] Studs of this design, with openings, ribs, and flanges and
channels, can be made of light gauge sheet steel. The steel can
actually be a lighter gauge than the gauge of conventional simple
C-section metal studs, because the various flanges, edges,
channels, and openings all contribute to make the stud stronger and
with a better load bearing character, than convention simple
C-section studs.
[0057] It will therefor be appreciated that the function of the
throat portions becomes even more effective as a barrier to heat
transfer.
[0058] The heat transferred, over a given time span, must depend,
both on the temperature gradient across the stud, and also the
volume of steel providing a heat transfer path. FIGS. 5, 6, 7, 8,
and 9 show sections of the various throat portions. These thermal
barriers contain the smallest volume of steel, at the locations
given, for transmission of heat across the stud. Thus whatever heat
gradient exists across the stud, heat transmission from one edge to
the other of the stud must be restricted to whatever heat values
can be transmitted at these restricted locations.
[0059] The reduction in heat transmission values for the present
studs compared with plain studs, from one edge to the other of the
stud, can be seen from the following figures for various gauges of
steel.
TABLE-US-00001 Steel gauge 20 (0.88 mm) 18 (1.15 mm) Plain stud
100% 100% Open web stud 4% to 8% 20% to 25%
[0060] These represent values developed theoretically.
[0061] In practice it is more likely that the values will be
subject to some margin, one way or the other, depending for example
on the heat loss conditions outside the exterior of a wall or
building, which may depend not merely on temperature, but also wind
chill and the like. There may be some slight variation due to
differences in steel formulations, and possibly, the volume an type
of thermal insulations placed in the wall between the studs.
[0062] It is clear that given a steel gauge which is lighter than
the gauge of a conventional plain stud, the actual volume of metal
at each throat portion or restriction is radically reduced.
[0063] Because the design of the open web stud makes it stronger
than conventional plain C-section studs, and because the design of
the stud restricts heat transfer to the throat portions only, the
stud of the present invention is greatly superior to conventional
C-section studs.
[0064] Along each edge of the web (12), in this embodiment, the web
is bent at a right angle to create web legs (42). Each web leg is
formed with an edge lip (44) turned inwardly at an angle of 90
degrees, in this case. In some larger studs the edge lip (44) may
be extended as shown in FIG. 2, and formed with a further
groove.
[0065] Each web leg (42) in this embodiment is formed of planar
sheet steel, in which are formed two parallel indented grooves
(46). The outer surface of each web leg defines a planar area (48).
This permits panels of dry wall to be laid flat on the planar area
(48) of the web leg outer surface. Where two panels of dry wall
material meet and abut, each panel edge will lie over one half the
width of the web leg (42). Dry wall screws will pass through the
edges of the two abutting panels of dry wall material, into their
respective grooves (46). Where the dry wall panels lie over one the
legs (42) of intermediate studs (10), they will be fastened by a
single line of dry wall screws. These screws will be received in
one of the two grooves (46).
[0066] In order to facilitate the location of the dry wall panels,
a central scribe line (50) is formed along each web leg (42). The
scribe line (50) is positioned along the median of the web leg,
equidistant between the two grooves (46). This enables the dry wall
installers to line up the panels precisely, so that any two
adjoining panels will overlap the web leg of one stud by the same
distance. This ensures that the screws will be inserted correctly
into the grooves in the web leg.
[0067] All formations and indentations in the web (12) are formed
from the web outer surface (14) and extend inwardly. This leaves
the web outer surface, and the outwardly directed surfaces of the
web legs (42) planar and flat so as to accept juxtaposition of
other materials. In the case of web legs (42) the material would be
dry wall panels,(FIG. 3), which can thus lie flat against the
planar outer surfaces (48) of the web legs (42).
[0068] Each of the grooves (46) is formed with linear angled sides
(52) (FIG. 10). The angled sides are formed in such a way as to
facilitate the insertion of self tapping screws (54). Self tapping
screws (54) are designed specifically for the fastening of dry wall
panels (56) (FIG. 3), to the steel studs (10). For this purpouse
the screws (54) have self drilling chisel points (58). The chisel
points have tips which are formed as a cone around cone angle. The
included angle of the cone point is in the region of approximately
40 to 50 degrees, thereabouts.
[0069] The included angle of the angled sides (52) of the grooves
(46) is between about 75 and 90 degrees. The grooves are therefor
wider, and the chisel points are narrower. In this way the chisel
point of each screw can reach completely down into the depth of the
groove. This ensures that the screw will start to drill into the
steel immediately the screw is rotated by the insertion tool,
usually a power driven screw driver.
[0070] If the screw is pressed in too hard causing the web leg to
deflect and bend, the chisel point will remain trapped in the
groove. This prevents the screw from twisting sideways and slipping
off the web leg. FIG. 10 shows a left side screw being about to
start drilling and a right side screw fully inserted.
[0071] Once fully inserted, it will be seen that the screw will
form the sheet metal in the groove of the web leg into a generally
trumpet shaped metallic tube (60). The metallic tube (60) so formed
can be seen to engage several threads of the screw (54), and thus
provide a secure hold.
[0072] Various different wall systems will require studs with
different specifications and dimensions.
[0073] Non load bearing studs will usually have web legs which have
a width of 0.92 mm to 102 mm.
[0074] Load bearing and heavier duty studs may have web legs with a
width of 152 mm and up.
[0075] Where two panels join the web legs of the studs function to
receive the edges of two edge abutting dry wall panels.
[0076] Accordingly the grooves (46) shall be equally spaced from
each other, on opposite sides of the median scribe line (50). The
grooves shall also be equally spaced from the web (12) and from the
lip (44).
[0077] The parameters of groove spacings B for various studs of
varying widths, and web leg widths A are shown below.
TABLE-US-00002 Stud Size Leg Width (A) Groove Separation (B) 92 mm
to 102 mm 41 to 51 mm 17 to 26 mm 152 mm 41 to 64 mm 17 to 39
mm
[0078] Studs of the invention, with some changes, can be used in
making thin shell composite concrete panels, reinforced with steel
studs.
[0079] The reinforcement studs (70), FIGS. 11, 12, 13, for this
purpouse, will be made essentially as described above, with the
same parts given the same reference numbers, with the exception
that there is only one web leg (42), bent at a right angle.
[0080] In place of the other web leg there is an embedment edge
(72) formed for embedment in a thin shell concrete panel (not
shown), usually from about 3.25 cm thick to about 4.5 cm thick,
although these figures are merely by way of illustration and
without limitation. Edge (72) consists of a right angular root
portion (74), extending from the web (12). A mid portion (76)
extends from root portion (74) at right angles, in this embodiment.
Openings (78) are formed through mid portion (76) at spaced
intervals to permit flow of concrete therethrough. The metal
portions (80) punched out from openings (78) remain joined along
one edge and are deflected so as to extend at right angles to one
side of mid portion (76).
[0081] A continuos lip (82) is formed along the edge of mid portion
(76), bent at a right angles and extending in a direction opposite
to metal portions (80).
[0082] Additional strength can be added to the embodiment of FIG. 1
and FIG. 11, as shown in FIGS. 14 and 15.
[0083] In this case the studs (90) have the same features as those
described above and have the same reference numbers. Additional
strength is provided by forming additional indentations (92), of
generally three sided shape, FIG. 14, or indentations (94) of
generally linear shape with rounded ends, FIG. 15.
[0084] In a still further embodiment, FIGS. 16, 17, and 18, studs
(100), indentations (102) of generally irregular triangle shape are
formed at the end of each rib (22). Circular rib openings (104) are
formed in the indentations (102), which function to define throats
for reduction of heat transmission, in the same way as in FIG. 1,
and FIG. 10.
[0085] The general effect, on heat transmission, of the open web
stud of the invention, as compared with a plain stud are shown in
FIGS. 19 and 20.
[0086] FIG. 19 show a length of plain stud (P). A series of arrows
(A 1) represent the heat transmission across the stud. The heat is
transmitted simply straight across the stud, without any
restriction. The greater the gauge of steel, the more heat will be
transmitted.
[0087] FIG. 20 shows a length of open web stud (10) according to
the invention. A series of arrows (A 2) represent the heat
transmission across such an open web stud of the invention.
[0088] It is clear that the heat is restricted to a narrow path, in
the stud (10) of FIG. 20, so that the actual heat transmitted will
be far less than that carried by a plain stud of FIG. 19.
[0089] The foregoing is a description of a preferred embodiment of
the invention which is given here by way of example only. The
invention is not to be taken as limited to any of the specific
features as described, but comprehends all such variations thereof
as come within the scope of the appended claims.
* * * * *