U.S. patent application number 11/499035 was filed with the patent office on 2007-02-08 for high strength runner.
Invention is credited to James Ferrell, Peter G. Jahn, Scott G. Jankovec, Richard McClain.
Application Number | 20070028554 11/499035 |
Document ID | / |
Family ID | 37728006 |
Filed Date | 2007-02-08 |
United States Patent
Application |
20070028554 |
Kind Code |
A1 |
Ferrell; James ; et
al. |
February 8, 2007 |
High strength runner
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: |
Ferrell; James; (Wheaton,
IL) ; McClain; Richard; (Chicago, IL) ;
Jankovec; Scott G.; (Elmhurst, IL) ; Jahn; Peter
G.; (Palos Park, IL) |
Correspondence
Address: |
COOK, ALEX, MCFARRON, MANZO, CUMMINGS & MEHLER LTD
SUITE 2850
200 WEST ADAMS STREET
CHICAGO
IL
60606
US
|
Family ID: |
37728006 |
Appl. No.: |
11/499035 |
Filed: |
August 4, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60705758 |
Aug 5, 2005 |
|
|
|
Current U.S.
Class: |
52/846 ;
52/506.07 |
Current CPC
Class: |
E04C 2003/0413 20130101;
E04C 2003/0439 20130101; E04C 2003/046 20130101; E04B 9/068
20130101; E04B 9/18 20130101 |
Class at
Publication: |
052/731.7 ;
052/506.07 |
International
Class: |
E04B 9/00 20060101
E04B009/00; E04B 2/00 20060101 E04B002/00; E04B 5/00 20060101
E04B005/00 |
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 panel support flanges
extending from the first edge of the web, a reinforcing bulb
extending from the second edge of the web, and a fin that is
generally co-planar with the central web extending from the
reinforcing bulb opposite to the central web.
2. The grid tee of claim 1 wherein the fin and the reinforcing bulb
each having a height that is variable, with the sum of the heights
of the fin and the bulb being a predetermined value.
3. The grid tee of claim 1 wherein the fin comprises a double layer
web with a reinforcing strip disposed between the layers.
4. The grid-tee of claim 1 wherein the fin includes a series of
spaced apertures adapted to receive hangar wire for suspending the
grid tee.
5. The grid tee of claim 1 wherein the fin includes a series of
spaced embossments, each embossment having an aperture adapted to
receive a hangar wire for suspending the grid tee.
6. The grid tee of claim 1 wherein the fin has an inverted,
drop-shaped cross section.
7. 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 formed with a
pair of opposed horizontally oriented cuts through the two layers
of the web and each stitch including a vertical displacement to
resist motion in a horizontal direction.
8. The grid tee of claim 7 wherein the vertical displacement in
each stitch comprises a vertical cut through the stitch.
9. The grid tee of claim 7 wherein the vertical displacement in
each stitch comprises a central portion of each stitch being
displaced back into a plane defined by the layers of the web.
10. A grid tee for a suspended ceiling, having a cross-section
generally in the form of an inverted T with a central double layer
web having first and second opposed edges, a pair of panel support
flanges extending from a first edge of the web, a reinforcing bulb
extending from the second edge of the web, and a plurality of
stitches at spaced intervals in the web to secure the layers
together, the stitches being formed with a pair of opposed,
horizontally oriented cuts through the two layers of the web and
each stitch including a vertical displacement to resist motion in a
horizontal direction.
11. The grid tee of claim 10 wherein the vertical displacement in
each stitch comprises a vertical cut through the stitch.
12. The grid tee of claim 10 wherein the vertical displacement in
each stitch comprises a central portion of each stitch being
displaced back into a plane defined by the layers of the web.
13. 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.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional
Application Ser. No. 60/705,758, filed Aug. 5, 2005, which is
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 1-1/2
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 a
beam can be increased by increasing the height of the beam, thus
increasing the moment of inertia of the beam. Modifications to
suspended ceiling beams have been proposed to increase the beam
height. See, U.S. Pat. No. 6,138,416, where the beam is formed with
a peak or angle at the top of the bulb to both increase the height
of the beam and to accommodate the frame of a lighting fixture that
may be supported by the beam.
SUMMARY OF THE INVENTION
[0005] By way of the present invention, an improved beam
configuration is provided that has an increased beam height to
provide 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 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.
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.
DETAILED DESCRIPTION
[0015] 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.
[0016] 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 between an enlarged top and bottom. The fin
14 extends from the bulb 12 generally opposite to, and coplanar
with, the web 16 of the runner. 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.
[0017] 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.
[0018] 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.
[0019] 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.
[0020] 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.
[0021] 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.
[0022] 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.
[0023] 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.
[0024] 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.
[0025] 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.
* * * * *