U.S. patent application number 12/024412 was filed with the patent office on 2008-06-26 for grid tee for suspended ceiling.
Invention is credited to Peter G. Jahn, Scott G. Jankovec.
Application Number | 20080148668 12/024412 |
Document ID | / |
Family ID | 39540904 |
Filed Date | 2008-06-26 |
United States Patent
Application |
20080148668 |
Kind Code |
A1 |
Jahn; Peter G. ; et
al. |
June 26, 2008 |
GRID TEE FOR SUSPENDED CEILING
Abstract
A suspended ceiling grid beam is provided that has an increased
beam height to provide enhanced resistance to downward deflection.
The beam has a cross-section generally in the form of an inverted
T, with a central web, a pair of panel support flanges extending
from one edge of the web, and a reinforcing bulb extending from the
other edge of the web. The reinforcing bulb has a generally planar,
fin-like structure extending therefrom opposite to and generally
co-planar with the central web.
Inventors: |
Jahn; Peter G.; (Palos Park,
IL) ; Jankovec; Scott G.; (Elmhurst, IL) |
Correspondence
Address: |
COOK, ALEX, MCFARRON, MANZO, CUMMINGS & MEHLER LTD
SUITE 2850, 200 WEST ADAMS STREET
CHICAGO
IL
60606
US
|
Family ID: |
39540904 |
Appl. No.: |
12/024412 |
Filed: |
February 1, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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|
11499035 |
Aug 4, 2006 |
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12024412 |
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60887850 |
Feb 2, 2007 |
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60705758 |
Aug 5, 2005 |
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Current U.S.
Class: |
52/506.07 |
Current CPC
Class: |
E04B 9/068 20130101;
E04B 2009/062 20130101 |
Class at
Publication: |
52/506.07 |
International
Class: |
E04C 3/08 20060101
E04C003/08; E04B 9/06 20060101 E04B009/06 |
Claims
1. A grid tee for a suspended ceiling having a cross-section
generally in the form of an inverted T with a central web with
first and second opposed edges, a pair of support flanges extending
from the first edge of the web, and a reinforcing bulb extending
from the second edge of the web, the reinforcing bulb having a
cross section with a narrow central portion and a relatively wider
top and bottom portion.
2. The grid-tee of claim 1 wherein the narrow central portion of
the reinforcing bulb includes a series of spaced apertures adapted
to receive hangar wire for suspending the grid tee.
3. The grid tee of claim 1 further comprising a fin extending
upwardly from the relatively wider top portion of the reinforcing
bulb.
4. The grid tee of claim 1 wherein the web comprises a double
layer, the layers being secured together by a plurality of stitches
at spaced intervals along the web, the stitches being forced with a
pair of opposed horizontally oriented cuts through the two layers
and each stitch including a vertical displacement to resist motion
in a vertical direction.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional
Application Ser. No. 60/887,850, filed Feb. 2, 2007, and is a
continuation in part of U.S. application Ser. No. 11/499,035, filed
Aug. 4, 2006, which claims the benefit of U.S. Provisional
Application Ser. No. 60/705,758, filed Aug. 5, 2005, all of which
are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to a beam or runner having a
generally inverted T cross section that is used in a support grid
for suspended ceilings.
[0003] Suspended ceilings typically require a support grid
comprising a plurality of interconnected beams for supporting
ceiling tiles or panels, light fixtures, air diffusers, etc. The
beams, also referred to as runners or tees, are generally inverted
T-shaped with a reinforcing bulb at the top, a vertical web
extending downwardly from the bulb, and opposed horizontal flanges
at the bottom of the web for supporting drop-end ceiling panels. In
standard practice, the height of the beam, as measured from the top
of the flange to the top of the beam, is approximately 11/2 inches,
so as to accommodate the frames of conventional fluorescent ceiling
light fixtures. The beams are typically made in a roll-forming
operation from a flat strip of sheet metal, as is well known in the
art.
[0004] It is well known that resistance to downward deflection in
the runner or tee is enhanced by the reinforcing bead at the upper
end of the vertical web, and various shapes for the reinforcing
bead have been proposed. See, e.g., U.S. Pat. No. 3,511,012, where
the reinforcing bead is triangle-shaped; U.S. Pat. No. 4,525,973,
where the reinforcing bead is rectangle-shaped; U.S. Pat. No.
4,549,383, where the reinforcing bead is square-shaped; U.S. Pat.
No. 4,932,186, where the reinforcing bead is circle-shaped; U.S.
Pat. No. 4,989,387, where the reinforcing bead is trapezoid-shaped;
U.S. Pat. No. 5,896,724, where the reinforcing bead is
diamond-shaped; and U.S. Pat. Nos. 4,817,357 and 6,138,416, where
the reinforcing bead is pentagon-shaped, with the peak pointing
either downward or upward.
SUMMARY OF THE INVENTION
[0005] By way of the present invention, a suspended ceiling grid
member is provided having an improved reinforcing bead
configuration that provides enhanced resistance to downward
deflection. The beam or grid tee has a cross-section generally in
the form of an inverted T, with a central web, a pair of panel
support flanges extending from one edge of the web, and a
reinforcing bulb extending from the other edge of the web. In
keeping with an aspect of the invention, the reinforcing bulb has
optionally includes a generally planar, "fin-like" structure
extending therefrom opposite to and generally co-planar with the
central web.
[0006] The fin has narrow width in comparison with the width of the
reinforcing bulb. In a first embodiment, the fin is generally
planar. In a second embodiment, the fin is more in the shape of a
drop, with the narrow portion of the drop being adjacent to the
reinforcing bulb.
[0007] In keeping with another aspect of the invention, the two
layers forming the web of the beam are stitched together to provide
additional resistance to torque.
[0008] Other features and advantages will become apparent upon
reference to the drawings and detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIGS. 1-5 show cross-sectional views of five different
embodiments of suspended ceiling grid beam that include a
reinforcing fin in accordance with the present invention.
[0010] FIG. 6 is a perspective view of a beam according to the
present invention, in which the fin includes a hole for receiving
the hanger wire for suspending the beam.
[0011] FIG. 7 is a fragmentary cross-sectional view of the
strengthening fin taken along line 7-7 of FIG. 6.
[0012] FIG. 8 is a perspective view of a beam according to the
present invention showing a stitching method in which the web of
the beam has a series of horizontal stitches with a vertical cut
therein spaced at intervals along the length of the runner.
[0013] FIG. 9 is a cross-sectional view of a stitch taken along
line 9-9 of FIG. 8.
[0014] FIG. 10 is a cross-sectional view of the stitch prior to
having the vertical cut being made therein.
[0015] FIG. 11 is a perspective view of the suspended ceiling grid
beam of FIG. 5.
[0016] FIG. 12 is a fragmentary cross-sectioned view of the ceiling
grid beam of FIGS. 5 and 11 showing a hanger wire.
DETAILED DESCRIPTION
[0017] With reference to FIGS. 1-5, a runner or tee 10 for use in a
suspended ceiling is disclosed comprising a reinforcing bead or
bulb 12, a central web 16, and a pair of opposed flanges 26 for
supporting ceiling panels or tiles, with a cap 27 covering the
exposed portions of the flanges 26, all as is well known in the
art.
[0018] In keeping with one aspect of the invention, the bulb 12 of
the runner 10 is modified to provide for a greater beam height than
the standard runner configuration. This is accomplished by forming
the bulb 12 with a central fin 14. While the bulb 12 typically has
a rectangular cross-sectional shape, as seen in FIGS. 1-4, other
cross-sectional shapes are contemplated, such as the I-beam or
"dog-bone" shape seen in FIG. 5, in which the bulb has a relatively
narrow central portion 28 between an enlarged top 30 and bottom 32.
The fin 14 extends from the bulb 12 generally opposite to, and
coplanar with, the web 16 of the runner and forms a continuous
curve about its upper end. This provides for greater strength, and
thus greater resistance to deflection, than a runner of identical
configuration but without the fin. The fin 14 preferably has a
generally flat configuration (as seen in FIGS. 1-3), and is narrow
in width as compared to the width of the strengthening bulb 12.
However, other narrow configurations may be used for the fin 14,
such as the inverted drop shape seen in FIGS. 4 and 5. The fin 14
may be of different heights, with the overall height of the runner
or tee being maintained, as shown in FIGS. 1 and 2. Thus, while the
total height of the tee is a predetermined value, the heights of
each of the bulb 12 and fin 14 may vary.
[0019] The enhanced strength provided by the fin configuration
permits the runner to be formed of thinner material than the prior
art runner without compromising the beam strength of the runner.
This results in a runner that is more economical to manufacture
(because less material is required) is easier to handle,
particularly in bulk or carton quantities (because each runner is
lighter in weight), and is easier to cut.
[0020] The fin 14 also facilitates the creation of a runner
suitable for long spans by stacking a second, inverted, runner on
top of the first runner, with their fins 14 lying along each other,
and preferably secured to each other through the fins. Such a
configuration can also be used to create a coffer.
[0021] With reference to FIG. 3, the fin 14 can be reinforced by
introducing an elongated strengthening element 18 of the same
material of the remainder of the runner that is bonded in place
between the opposed faces of the two layers that comprise the fin
by, e.g., adhesive, solder, spot welding, plasma welding, toggle
locks, or by stitching or the creation of embossed hanger wire
holes in the fin, as discussed below.
[0022] To provide the beam with added resistance to torque, the two
layers of the web are preferably secured to each other by means of
locking stitches or lances that mechanically join together the two
layers of the web. See, e.g., U.S. Pat. No. 4,489,529, which is
incorporated herein by reference. This patent shows the web of a
suspended ceiling beam fastened together by either a horizontal or
a vertical stitch.
[0023] The stitch 20 may be of any configuration known in the art,
but is preferably of the configuration shown in FIGS. 8 and 9.
FIGS. 8 and 9 show a 2-axis stitch 20 applied at spaced intervals
along the length of the web. This stitch 20 includes a vertical cut
21 to resist motion in the horizontal direction.
[0024] The stitches 20 are preferably made as part of the roll
forming operation for the beam in which the beam is passed between
a pair of cooperating rollers. One roller has a series of small
punches with opposed cutting edges spaced around its circumference,
while the other roller has a continuous circumferential groove
aligned so that the punches penetrate the groove. Thus, in a first
roll pass, the web passes through the rollers, and the punches in
the first wheel cut out parallel slots and displace a slug out of
the plane of the web and into the groove of the second roller, with
the slug from one of the layers protruding through the hole in the
other layer to form a horizontally-oriented D-shaped stitch, when
viewed in horizontal section as shown in FIG. 10. This resists
vertical displacement between the two layers of the vertical web.
See also U.S. Pat. No. 6,047,511, FIGS. 1-2a and associated
description, and U.S. Pat. No. 5,979,055, FIGS. 1-3 and associated
description, both of which are incorporated by reference. Thus,
each stitch comprises two horizontally oriented legs displaced out
of the plane of the web that have their free ends engaging each
other and, preferably displaced back to or into the plane of the
web.
[0025] The beam is then passed through a second pair of rollers in
which one of the rollers has an edge that creates a vertical
displacement in the D-stitch formed in the first roll pass to
complete the stitch. As shown in FIG. 9, the illustrated stitch
includes a vertical cut that completely severs the layers of the
web. However, this is not required and the second roll pass
operation may simply press a central portion of the D-shaped stitch
back into the plane of the layers forming the web.
[0026] As shown in FIG. 7, the fin 14 is preferably provided with a
series of spaced holes 22 for receiving the hanger wire 24 for
suspending the assembled grid from the ceiling. Preferably, the
series of holes 22 is spaced so that a hole 22 is aligned with
apertures in the web of the beam for receiving the cross beams.
Having the fin 14, rather than the web 16, carry the hanger wire
allows for the hanger wire to be aligned with the cross-tee and for
the hanger wire to be more tightly wrapped about itself. This, in
turn, lessens the likelihood of damaging the edges of the ceiling
tiles by the hanger wire when the tiles are dropped into place on
the flanges 26 of the runner 10 because there is greater clearance.
The greater clearance also facilitates faster installation of the
ceiling tile. The hanger holes 22 are also preferably formed as
part of an embossment 28 for additional strength. The embossment 28
also provides a tapered hole, which allows easier hanger wire
insertion.
[0027] Additional advantages accrue to runners in which the
reinforcing bead 12 includes the dog bone profile as seen in FIG.
5. With reference to FIGS. 11 and 12, hanger wire holes 34 are
punched in the narrow central portion 28 of the reinforcing bead 12
where the opposing surfaces are at a minimum distance apart. The
hanger wire holes 34, as illustrated, have a generally elongated
shape. In one embodiment, the hanger wire holes have a major axis
measuring approximately 1/4'' and a minor axis measuring
approximately 3/16'' and are spaced at intervals of approximately
17/8'' along the length of the reinforcing bead. Preferably, the
profile of the bead is such that there is an angled transition 36
between each of the wide top and bottom portions 30, 32 and the
narrow central portion 28. As a consequence, the angled portions 36
can act as guiding surfaces to facilitate the threading of the
hanger wire 38 through the hole. Further, the closeness of the
opposing surfaces of the narrow portion 28 allow for greater
off-angle installation of the hanger wire 38. While the embodiment
of FIGS. 5 and 11 includes a fin 14, a fin is not required in order
to obtain the foregoing advantages.
[0028] Thus, an improved beam for a suspended ceiling grid has been
provided. While the invention has been described in terms of
certain preferred embodiments, there is no intent to limit the
invention to the same. Instead, the invention is defined by the
scope of the following claims.
* * * * *