U.S. patent application number 10/829564 was filed with the patent office on 2005-06-30 for curtain wall system with enhanced resistance to blast forces.
Invention is credited to Biebuyck, Lawrence.
Application Number | 20050138889 10/829564 |
Document ID | / |
Family ID | 34704026 |
Filed Date | 2005-06-30 |
United States Patent
Application |
20050138889 |
Kind Code |
A1 |
Biebuyck, Lawrence |
June 30, 2005 |
Curtain wall system with enhanced resistance to blast forces
Abstract
Disclosed is a curtain wall system used for building exteriors.
The curtain wall system includes at least one vertical mullion and
at least one horizontal sill member. Either the vertical mullion,
the horizontal sill member, or both are formed to include a channel
of increased depth to facilitate the receipt of a panel member
therein. The panel member is secured with a bonding agent. The
channel of the vertical and horizontal mullions may be oriented
near at least one of a front edge and a back edge or substantially
near a center of the vertical mullion and horizontal sill member.
This Abstract is provided to comply with rules requiring an
Abstract that allows a searcher or other reader to quickly
ascertain subject matter of the technical disclosure. This Abstract
is submitted with the understanding that it will not be used to
interpret or limit the scope or meaning of the claims. 37 CFR
1.72(b).
Inventors: |
Biebuyck, Lawrence;
(Garland, TX) |
Correspondence
Address: |
JENKENS & GILCHRIST, PC
1445 ROSS AVENUE
SUITE 3200
DALLAS
TX
75202
US
|
Family ID: |
34704026 |
Appl. No.: |
10/829564 |
Filed: |
April 22, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60465253 |
Apr 24, 2003 |
|
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Current U.S.
Class: |
52/782.1 |
Current CPC
Class: |
E04B 2/96 20130101 |
Class at
Publication: |
052/782.1 |
International
Class: |
E04C 002/00 |
Claims
What is claimed is:
1. A curtain wall system comprising: at least one vertical mullion
formed with a channel having a depth sufficiently increased for
securing a panel member therein for enhanced resistance to a blast
force; at least one horizontal sill member formed with a channel
for receiving said panel member; and wherein the channel of said
horizontal mullion is formed of an increased depth for enhanced
resistance to a blast force.
2. The curtain wall system of claim 1, wherein the channel of said
vertical mullion is oriented near at least one of a front edge and
a back edge of said vertical mullion.
3. The curtain wall system of claim 1, wherein the channel of said
horizontal sill member is oriented near at least one of a front
edge and a back edge of said horizontal sill member.
4. The curtain wall system of claim 1, further comprising an
increased amount of a bonding agent placed in the channel of said
horizontal sill member.
5. The curtain wall system of claim 1, wherein said vertical
mullion is formed as a single extrusion.
6. The curtain wall system of claim 1, wherein said horizontal sill
member is formed as a single extrusion.
7. The curtain wall system of claim 1, wherein said vertical
mullion is formed so as to include a plurality of channels.
8. A vertical mullion for forming a curtain wall, the vertical
mullion comprising: at least one channel for receiving a panel
member, the channel including: a first side member of an increased
length for receiving an increased portion of the panel member; at
least one of a base member and a sill member for receiving a
portion of the panel member; and a second member of an increased
length for receiving an increased portion of the panel member.
9. The vertical mullion of claim 8, wherein the channel is oriented
near an edge of said vertical mullion.
10. The vertical mullion of claim 8, wherein at least one of the
first and second side members is oriented to receive substantially
one inch or more of a bonding agent.
11. The vertical mullion of claim 8, wherein the bonding agent
comprises silicon.
12. The vertical mullion of claim 8, wherein said vertical mullion
is formed as a single extrusion.
13. The vertical mullion of claim 8, wherein said at least one
channel comprises a plurality of channels.
14. The vertical mullion of claim 13, wherein the base member is
common between two channels of the plurality of channels.
15. A horizontal mullion for forming a curtain wall, the horizontal
mullion comprising: a channel for receiving a panel member, the
channel including: a first side member of an increased length for
receiving an increased portion of the panel member; a base member
for receiving a base portion of the panel member; and a second
member of an increased length for receiving an increased portion of
the panel member.
16. The horizontal mullion of claim 15, wherein the channel is
oriented near an edge of said horizontal mullion.
17. The horizontal mullion of claim 15, wherein at least one of the
first and second side members is oriented to receive substantially
one inch or more of a bonding agent.
18. The horizontal mullion of claim 17, wherein the bonding agent
comprises silicon.
19. The horizontal mullion of claim 15, wherein said horizontal
mullion is formed as a single extrusion.
20. The horizontal mullion of claim 15, wherein said at least one
channel comprises a plurality of channels.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority from, and incorporates by
reference for any purpose the entire disclosure of, U.S.
Provisional Application Ser. No. 60/465,253 filed Apr. 24,
2003.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to curtain walls used for
building exteriors and, more particularly, but not by way of
limitation, to methods of and apparatus for constructing and
assembling curtain walls with improved resistance to hurricane and
blast forces.
[0004] 2. History of the Related Art
[0005] The use of curtain walls for building construction is
wide-spread and generally accepted by municipal building standards.
They are cost effective and often aesthetically appealing. Curtain
walls are typically constructed of extruded aluminum frame support
members having generally U-shaped channels (although other shapes
may apply) for supporting a plurality of panel members that serve
as the exterior of a building. Such panel members are most often
panes of glass, and often double pane glass sections, but other
paneled building materials such as aluminum, granite, slate, or
concrete are also utilized. Such panel members are often of
identical size and shape. However, near doors, opening windows, or
other access points into the building, panel members of different
sizes and shapes may be utilized.
[0006] More specifically, such curtain walls generally include
multiple vertical and horizontal members, or mullions. In some
instances, the curtain wall system includes a plurality of
horizontal sill members having at least one portion forming an
upwardly facing region (or channel) at the bottom of a wall
section. The curtain wall systems also include horizontal head
members having a downwardly facing channel at the top of a wall
section, and a plurality of vertical mullions running between the
sill member and head members. Panel members are then generally
supported by the channels of the sill member and the head member.
Vertical joints between adjacent panel members are formed at the
mullions. In some designs, the mullions are disposed interiorly of
the sill member, the head member, and the panel members so that
only the joint between adjacent panel members, and not the mullions
themselves, are visible from the exterior of the building. The
designs do, however, vary, depending upon the desired aesthetics of
the curtain wall construction, and the architecture involved
therewith. One such design is set forth and shown in U.S. Pat. No.
4,899,508, assigned to the assignee of the present invention.
[0007] In another curtain wall construction, multiple panel members
are typically arranged side-by-side and are secured and sealed
between a sill member and a head member, with their vertical joints
overlapping at a mullion. This vertical joint must then be sealed
from both the interior and exterior of the building using both
resilient gaskets, sealant tapes, sealant, and/or structural
silicone, as described for reference purposes below.
[0008] Referring now to FIG. 1, a schematic, cross-sectional view
of a sill member 10 of an exemplary curtain wall is shown. The sill
member 10 secures a curtain wall to a structural support surface
such as a concrete slab 12. The concrete slab 12 of this
illustration may be disposed at ground level it may comprise one of
a plurality of floor surfaces of a high rise building or, in some
embodiments, positioned behind/within the curtain wall system. In
such designs, the sill member 10 may simply be a horizontal member
secured to the vertical mullion. Although not shown in FIG. 1, a
head member similar to the sill member 10 secures the curtain wall
to a concrete slab between floors of a building or other building
structures, and a plurality of mullions span between the sill
member 10 and the head member. The sill member 10 is typically
formed as an integral aluminum extrusion. The sill member 10 also
generally includes a channel section 14, an anchoring section 16
disposed interiorly of a channel section 14, and a cover 18.
[0009] Still referring to FIG. 1, the channel section 14 and the
cover 18 cooperate to secure the panel member 20 to the sill member
10. More specifically, the channel section 14 includes a base 14a
and two legs 14b and 14c that form a upwardly facing U-shaped
channel. A support member 22 rests on the top surface of the base
14a. The exterior leg 14b has a groove 24 proximate the upper end
of its interior surface facing the panel member 20, and the
interior leg 14c has a support surface 26 proximate the upper end
of its interior surface. The cover 18 has a downward projecting leg
28 that engages a groove 30 on the exterior surface of the interior
leg 14c. The cover 18 also has two tongues 32, 49, one proximate to
each end of the cover 18. The panel member 20 is placed within the
channel section 14 on an upper surface of a setting block 34. An
exterior and interior gasket 36, 38 are located at the upper end of
the exterior and interior legs 14b, 14c. The gaskets 36, 38 operate
to hold the panel member 20 in the channel section 14. The setting
block 34 is disposed on the top surface of the support member 22.
The exterior gasket 36 has a tongue 36a that engages the groove 24
of the exterior leg 14b. The exterior gasket 36 is typically
pre-installed in groove 24 of the exterior leg 14b during the
manufacture of the sill member 10. The interior gasket 38 has a
groove 38a that engages the tongue 32 of the cover 18 and the
support surface 26 of the interior leg 14c. The channel section 14
further includes a plurality of support legs 40 below base 14a.
[0010] The anchoring section 16 includes a base 16a, an interior
leg 16b, and a plurality of support legs 42 below the base 16a. The
base 16a has a plurality of holes 44 spaced along its length for
receiving fasteners 46 to secure the sill member 10 to the concrete
slab 12. The interior leg 16b has a groove 48 for receiving the
tongue 49 of the cover 18. The cover 18 stabilizes the interior
gasket 38 that presses against the panel member 20 and also
conceals the base 16a of the anchoring section 16 so that the
fasteners 46 are not visible.
[0011] The following technique is typically used to install the
panel member 20 of such a curtain wall. The sill member 10 is laid
on a shim 56 in the proper position on the concrete slab 12 and is
used as a template to drill holes into the concrete slab 12 for
each fastener 46. One should note that the shim 56 does not run
continuously along the length of the sill member 10. Instead, the
shim 56 is used at low points of the concrete slab 12 to level the
sill member 10, if necessary. The sill member 10 is removed from
the shim 56, and a hole 50 with a larger diameter is drilled in the
place of each of the holes drilled using the sill member 10. A
structural insert 52 is secured within each of the holes 50 via
epoxy or other conventional means. Each insert 52 has an internally
threaded hole 54 for receiving fasteners 46. The sill member 10 is
repositioned on the shim 56 and secured to the concrete slab 12
using fasteners 46. A sealant 58 is disposed continuously on the
concrete slab 12 along both the exterior and interior sides of the
shim 56. A head member similar to the sill member 10 is secured to
part of the building structure using the above-described
techniques. Vertical mullions are secured between the sill member
10 and the head member at appropriate intervals along the curtain
wall. The vertical mullions are attached at each side to sill
members 10. The support member 22 is disposed on the base 14a of
the sill member 10, and the setting block 34 is disposed on the
support member 22. The panel member 20 is then installed from the
exterior of the building, typically first being tilted into the
channel section of the head member, and then being dropped into the
channel section 14 of the sill member 10. The cover 18 is installed
in the sill member 10, and a glazing stop is installed in the head
member of the curtain wall. The interior gasket 38 is disposed on
the tongue 32 of the cover 18 of the sill member 10, and a similar
gasket is disposed on the tongue of the glazing stop of the head
member.
[0012] Of course, multiple panel members 20 are typically arranged
side-by-side and are secured and sealed between the sill member 10
and the head member in this manner, with their vertical joint
overlapping at a mullion. This vertical joint must then be sealed
from both the interior and exterior of the building using both
resilient gaskets and/or structural silicon.
[0013] While such curtain walls, and other conventional curtain
walls, have proved to be reliable commercial building systems,
other design parameters have relatively recently been brought into
focus. For example, the ability of a curtain wall system to
withstand impact from strong forces, such as hurricane force winds
or an unexpected blast, is under study. To affect such parameters,
the curtain wall system must be able to absorb the energy of a
blast or hurricane force loads and secure the panel members placed
thereon. In this manner the curtain wall system prevents the panel
members, often glass, from being blown into the interior of the
building causing additional destruction and injury. Relative to the
design aspects of the present invention, an example of a
storm-resistant window is set forth and shown in U.S. Pat. No.
5,560,149. In this particular system, a storm-resistant window
includes a window frame and a window sash for preferably aluminum
extruded frame members, a glass and polymer safety glass, clamping
glazing beads that bear sealingly on the glass, and a sash locking
clasp arrangement. The window is said to resist impact
characteristic of windblown hurricane debris, for example, and
resilient enough to damp wind loads induced by 75 mph (120 kph)
winds, with resilient arching and twisting of the frame members.
Such focus upon the window construction further manifests the
interest of the building industry to create a curtain wall system
accommodating the forces generated by hurricane force winds and/or
unexpected blasts. Various types of glass, such as safety glass,
laminated glass, etc., may be utilizes to form curtain walls for
buildings.
[0014] The current use of structural silicone to seal glass panel
members into a curtain wall system typically specifies a bonding
agent thickness of 3/8" to 5/8". Although normally successful for
conventional loads, in accordance with embodiments of the present
invention this thickness is increased to withstand blast impact
loading. When increasing the amount of bonding agent utilized in
the curtain wall, an additional surface may be added within the
curtain wall system to accommodate the additional bonding
agent.
SUMMARY OF THE INVENTION
[0015] The present invention relates to curtain walls used for
building exteriors and the assembly of a building curtain wall with
improved blast resistance. More particularly, one aspect of the
present invention relates to a curtain wall system including at
least one vertical mullion formed with a channel having a depth
sufficiently increased for securing a panel member therein for
enhanced resistance to a blast force. The system also includes at
least one horizontal mullion formed with a channel for receiving
the panel member. The channel of the horizontal mullion is formed
of an increased depth for enhanced resistance to a blast force.
[0016] In another aspect, the present invention relates to a
vertical mullion for forming a curtain wall. The vertical mullion
includes at least one channel for receiving a panel member. The
channel includes a first side member of an increased length for
receiving an increased portion of the panel member, a base member
for receiving a base portion of the panel member, and a second
member of an increased length for receiving an increased portion of
the panel member.
[0017] In yet another aspect, the present invention relates to a
horizontal mullion for forming a curtain wall. The horizontal
mullion includes a channel for receiving a panel member. The
channel includes a first side member of an increased length for
receiving an increased portion of the panel member, a base member
for receiving a base portion of the panel member, and a second
member of an increased length for receiving an increased portion of
the panel member.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] For a more complete understanding of the present invention,
and for further objects and advantages thereof, reference is made
to the following description taken in conjunction with the
accompanying drawings in which:
[0019] FIG. 1 is a schematic, cross-sectional view of conventional
curtain wall construction;
[0020] FIG. 2 is a cross-sectional view of a horizontal sill member
incorporating the principles of the present invention and having a
channel of increased depth adopted from facilitating the
application of increased bonding agent between the panel member and
the horizontal mullion;
[0021] FIG. 3 is a cross-sectional view of a vertical mullion of an
alternative embodiment of a curtain wall system having a channel of
increased depth in accordance with the principles of the present
invention;
[0022] FIG. 4 is a cross-sectional view of a vertical mullion of a
curtain wall system having panel members mounted therein in
accordance with the principles of the present invention;
[0023] FIG. 5 is a cross-sectional view of a vertical mullion of an
alternative embodiment of a curtain wall system incorporating the
principles of the present invention and illustrating the increased
uses of silicon therewith; and
[0024] FIG. 6 is a cross-sectional view of a head member
incorporating the principles of the present invention and having a
channel of increased depth adopted from facilitating the
application of increased bonding agent between the panel member and
the head member.
DETAILED DESCRIPTION OF THE INVENTION
[0025] It has been discovered that a number of advantages can be
obtained by assembling a curtain wall system with the use of an
increased amount of bonding agent for retaining a panel member
therein. This increase in the amount of bonding agent can result in
an improvement in the securement of the panel members within the
curtain wall system and thus the structural capability thereof.
Panel members mounted in a channel having a relatively small
bonding surface area will manifest less adherence and structural
interconnection with the horizontal and vertical mullions extending
therearound than those panel members mounted in a channel of
increased depth as set forth as shown in the present invention. For
example, in some embodiments, the depth of the channel may be
substantially on the order of one inch or more. In some
embodiments, a system is created with minimal sight line width and
maximum bonding surfaces with no exposed fasteners.
[0026] Referring to FIGS. 2-6 there are shown multiple views of
curtain wall system 200 having panel members 202 secured or
mountable therein. In FIGS. 2-4, the panel members 202 are shown
positioned within a channel 204 of a horizontal sill member 206 and
channels 300 of a vertical mullion 302. The vertical mullion 302
may be formed of several pieces or formed as one integral piece. It
may be seen that the channels 204, 300 are of increased depth for
facilitating receipt of a bonding agent 208, such as silicone,
therein and the adherence of a panel member 202 thereto.
[0027] The utilization of panel members 202 formed of glass having
increased structural integrity may not necessitate the use of
enlarged channels 204, 300 in accordance with the principles of the
present invention because such certain types of reinforced glass
have sufficient structural stiffness. Less expensive glass, may bow
under hurricane force winds and/or related blast forces, which may
place the bonding agent in a sheer force failure mode relative to
the surrounding vertical mullions 302 and horizontal mullions 206.
With the utilization of less expensive, more flexible, glass panel
members 202, it has been noted that the use of the increased
quantity of the bonding agent 208, such as silicone, and in
conjunction with the increased depth of the channels 204 300 as
shown in the figures herein will provide an improved blast
resistance.
[0028] The channel 204 of the horizontal sill member 206 includes a
first side member 204A, a base member 204B, and a second side
member 204C. The base member 204B is sufficiently deep in the
channel 204 to increase the amount of the panel member 202 that
resides in the channel 204. By increasing the depth of the base
member 204B, an increased amount of the second side member 204C is
in contact with the bonding agent 208 and the panel member 202.
[0029] In a similar manner, the channel 300 of the vertical
mullions 302 has an increased depth to accommodate blast forces.
Each channel 300 includes a first side member 300A, a base member
300B, and a second side member 300C. The first and second side
members 300A, 300C are of an increased length in order to increase
the depth of the channel 300. The increased depth of the channel
300 allows a larger portion of the panel member 202 to reside in
the channel 300. In addition, the increased depth allows an
increased portion of sealant 304 to be placed between the panel
member and the second side member 300C.
[0030] Referring now to FIG. 5, an alternate embodiment of the
vertical mullions 302 of the curtain wall system 200 is
illustrated. As opposed to forming a vertical mullion 302 with a
channel 300 near an edge of the vertical mullion 302, in the
alternate embodiment, the channel 300 is formed substantially near
the center of the vertical mullion 302. Again, the channel 300 is
of an increased depth for increasing the surface area of the panel
member 202 that is in contact with the bonding agent 208. Although
the vertical mullions 302 shown herein are illustrated as having a
particular configuration, any configuration of vertical or
horizontal mullion may be formed with a channel with an increased
depth in accordance with embodiments of the present invention.
[0031] FIG. 6 illustrates a cross-sectional view of a head member
206a in accordance with an embodiment of the present invention. The
head member 206a is similar in structure to the horizontal sill
member 206 of FIG. 2. The head member 206a receives a top portion
of the panel member 202 in a channel 204 of an increased depth and
sealant 304 may be placed therein for sealing the channel 204 and
the panel member 202.
[0032] It may thus be seen that a curtain wall system could thus be
constructed in accordance with the principles of the present
invention to provide the structural integrity to withstand certain
forces such as hurricane winds and/or impacts and/or blast impacts
of select characteristics to be certain design criteria and/or
construction regulations/municipal code restrictions in an
economically viable manner.
[0033] It is thus believed that the operation and construction of
the present invention will be apparent from the foregoing
description. While the method and apparatus shown or described have
been characterized as being preferred it will be obvious that
various changes and modifications may be made therein without
departing from the spirit and scope of the invention.
* * * * *